Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.
The circulation of blood through the CORONARY VESSELS of the HEART.
A number of ligaments on either side of, and serving as a radius of movement of, a joint having a hingelike movement. They occur at the elbow, knee, wrist, metacarpo- and metatarsophalangeal, proximal interphalangeal, and distal interphalangeal joints of the hands and feet. (Stedman, 25th ed)
A polygonal anastomosis at the base of the brain formed by the internal carotid (CAROTID ARTERY, INTERNAL), proximal parts of the anterior, middle, and posterior cerebral arteries (ANTERIOR CEREBRAL ARTERY; MIDDLE CEREBRAL ARTERY; POSTERIOR CEREBRAL ARTERY), the anterior communicating artery and the posterior communicating arteries.
Recesses of the kidney pelvis which divides into two wide, cup-shaped major renal calices, with each major calix subdivided into 7 to 14 minor calices. Urine empties into a minor calix from collecting tubules, then passes through the major calix, renal pelvis, and ureter to enter the urinary bladder. (From Moore, Clinically Oriented Anatomy, 3d ed, p211)
Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.
The circulation of blood through the BLOOD VESSELS of the BRAIN.
Radiography of the vascular system of the heart muscle after injection of a contrast medium.
Radiography of the vascular system of the brain after injection of a contrast medium.
Complete blockage of blood flow through one of the CORONARY ARTERIES, usually from CORONARY ATHEROSCLEROSIS.
Radiography of blood vessels after injection of a contrast medium.
The circulation of BLOOD through the LIVER.
Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.
The ligament that travels from the medial epicondyle of the FEMUR to the medial margin and medial surface of the TIBIA. The medial meniscus is attached to its deep surface.
The symptom of paroxysmal pain consequent to MYOCARDIAL ISCHEMIA usually of distinctive character, location and radiation. It is thought to be provoked by a transient stressful situation during which the oxygen requirements of the MYOCARDIUM exceed that supplied by the CORONARY CIRCULATION.
A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.
Application of a ligature to tie a vessel or strangulate a part.
The condition of an anatomical structure's being constricted beyond normal dimensions.
Use of a balloon CATHETER to block the flow of blood through an artery or vein.
The veins and arteries of the HEART.
The flow of BLOOD through or around an organ or region of the body.
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.
Motion pictures of the passage of contrast medium through blood vessels.
Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose.
The arterial trunk that arises from the abdominal aorta and after a short course divides into the left gastric, common hepatic and splenic arteries.
The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.
The arterial blood vessels supplying the CEREBRUM.
Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.
Changes in the observed frequency of waves (as sound, light, or radio waves) due to the relative motion of source and observer. The effect was named for the 19th century Austrian physicist Johann Christian Doppler.
Pathological conditions of intracranial ARTERIES supplying the CEREBRUM. These diseases often are due to abnormalities or pathological processes in the ANTERIOR CEREBRAL ARTERY; MIDDLE CEREBRAL ARTERY; and POSTERIOR CEREBRAL ARTERY.
Narrowing or constriction of a coronary artery.
Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)
The main artery of the thigh, a continuation of the external iliac artery.
A noninflammatory, progressive occlusion of the intracranial CAROTID ARTERIES and the formation of netlike collateral arteries arising from the CIRCLE OF WILLIS. Cerebral angiogram shows the puff-of-smoke (moyamoya) collaterals at the base of the brain. It is characterized by endothelial HYPERPLASIA and FIBROSIS with thickening of arterial walls. This disease primarily affects children but can also occur in adults.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
Branch of the common carotid artery which supplies the exterior of the head, the face, and the greater part of the neck.
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
The development of new BLOOD VESSELS during the restoration of BLOOD CIRCULATION during the healing process.
A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.
Narrowing or stricture of any part of the CAROTID ARTERIES, most often due to atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce THROMBUS formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a TRANSIENT ISCHEMIC ATTACK; CEREBROVASCULAR ACCIDENT; or temporary blindness (AMAUROSIS FUGAX). (From Adams et al., Principles of Neurology, 6th ed, pp 822-3)
A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).
Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.
NECROSIS occurring in the MIDDLE CEREBRAL ARTERY distribution system which brings blood to the entire lateral aspects of each CEREBRAL HEMISPHERE. Clinical signs include impaired cognition; APHASIA; AGRAPHIA; weak and numbness in the face and arms, contralaterally or bilaterally depending on the infarction.
Radiographic visualization or recording of a vein after the injection of contrast medium.
Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.
Elements of limited time intervals, contributing to particular results or situations.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.
The vessels carrying blood away from the heart.
The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).
Diversion of blood flow through a circuit located outside the body but continuous with the bodily circulation.
The circulation of the BLOOD through the LUNGS.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.
Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.

The effect of cardiac contraction on collateral resistance in the canine heart. (1/1214)

We determined whether the coronary collateral vessels develop an increased resistance to blood flow during systole as does the cognate vascular bed. Collateral resistance was estimated by measuring retrograde flow rate from a distal branch of the left anterior descending coronary artery while the main left coronary artery was perfused at a constant pressure. Retrograde flow rate was measured before and during vagal arrest. We found that in 10 dogs the prolonged diastole experienced when the heart was stopped caused no significant change in the retrograde flow rate, which indicated that systole has little effect on the collateral resistance. However, when left ventricular end-diastolic pressure was altered by changing afterload or contractility, a direct relationship between end-diastolic pressure and collateral resistance was noted.  (+info)

Effect of coronary occlusion on left ventricular function with and without collateral supply during beating heart coronary artery surgery. (2/1214)

OBJECTIVE: To study the effects of coronary occlusion and collateral supply on left ventricular (LV) function during beating heart coronary artery surgery. DESIGN: Prospective intraoperative study, performed at baseline, during wall stabilisation, coronary artery occlusion, and 2 and 10 minutes after reperfusion. Transoesophageal M mode echocardiograms, simultaneous high fidelity LV pressure, and thermodilution cardiac output were measured. LV anterior wall thickening, thinning velocities, thickening fraction, regional work, and power production were derived. Asynchrony during the isovolumic periods was quantified as cycle efficiency. SETTING: Tertiary referral cardiac centre. PATIENTS: 14 patients with stable angina, mean (SD) age 62 (7) years, undergoing left anterior descending artery grafting using the "Octopus" device. RESULTS: Collaterals were absent in nine patients and present in five. Epicardial stabilisation did not affect LV function. Results are expressed as mean (SD). Coronary occlusion (15.6 (2) minutes) depressed anterior wall thickening (1.4 (0.6) v 2.6 (0.6) cm/s) and thinning velocities (1.4 (0.5) v 3.0 (0.6) cm/s), regional work (2.2 (0.8) v 4.6 (0.6) mJ/cm2), and power (21 (4) v 33 (5) mW/cm2) in patients without collaterals (p < 0.05 for all), but only wall thinning (3.5 (0.5) v 4.8 (0.5) cm/s, p < 0.05) in patients with collaterals. All returned to baseline within 10 minutes of reperfusion. Cycle efficiency and regional work were impaired at baseline and fell during occlusion, regardless of collaterals. Within 10 minutes of reperfusion both had increased above baseline. CONCLUSIONS: Coronary occlusion for up to 15 minutes during beating heart coronary artery surgery depressed standard measurements of systolic and diastolic anterior wall function in patients without collaterals, but only those of diastolic function in patients with collaterals. Regional synchrony decreased in both groups. All disturbances regressed within 10 minutes of reperfusion.  (+info)

Late massive haemoptyses from bronchopulmonary collaterals in infarcted segments following pulmonary embolism. (3/1214)

Massive, recurrent haemoptyses requiring blood transfusions occurred in a patient who had been diagnosed as having pulmonary thromboembolism 3 months earlier. To the authors' knowledge this is the first case report of this kind, in which massive haemoptyses were proved to be caused by large bronchopulmonary collaterals that had developed in the infarcted lung segments affected by embolism. Selective embolization of the collaterals proved to be therapeutic and life saving.  (+info)

Isolated femoropopliteal bypass graft for limb salvage after failed tibial reconstruction: a viable alternative to amputation. (4/1214)

PURPOSE: Femoropopliteal bypass grafting procedures performed to isolated popliteal arteries after failure of a previous tibial reconstruction were studied. The results were compared with those of a study of primary isolated femoropopliteal bypass grafts (IFPBs). METHODS: IFPBs were only constructed if the uninvolved or patent popliteal segment measured at least 7 cm in length and had at least one major collateral supplying the calf. When IFPB was performed for ischemic lesions, these lesions were usually limited to the digits or small portions of the foot. Forty-seven polytetrafluoroethylene grafts and three autogenous reversed saphenous vein grafts were used. RESULTS: Ankle brachial pressure index (ABI) increased after bypass grafting by a mean of 0.46. Three-year primary life table patency and limb-salvage rates for primary IFPBs were 73% and 86%, respectively. All eight IFPBs performed after failed tibial bypass grafts remained patent for 2 to 44 months, with patients having viable, healed feet. CONCLUSION: In the presence of a suitable popliteal artery and limited tissue necrosis, IFPB can have acceptable patency and limb-salvage rates, even when a polytetrafluoroethylene graft is used. Secondary IFPB can be used to achieve limb salvage after failed tibial bypass grafting.  (+info)

Relief of obstructive pelvic venous symptoms with endoluminal stenting. (5/1214)

PURPOSE: To select patients for percutaneous transluminal stenting of chronic postthrombotic pelvic venous obstructions (CPPVO), we evaluated the clinical symptoms in a cohort of candidates and in a series of successfully treated patients. METHODS: The symptoms of 42 patients (39 women) with CPPVO (38 left iliac; average history, 18 years) were recorded, and the venous anatomy was studied by means of duplex scanning, subtraction venography, and computed tomography or magnetic resonance imaging. Successfully stented patients were controlled by means of duplex scanning and assessment of symptoms. RESULTS: The typical symptoms of CPPVO were reported spontaneously by 24% of patients and uncovered by means of a targeted interview in an additional 47%. Of 42 patients, 15 had venous claudication, four had neurogenic claudication (caused by dilated veins in the spinal canal that arise from the collateral circulation), and 11 had both symptoms. Twelve patients had no specific symptoms. Placement of a stent was found to be technically feasible in 25 patients (60%), was attempted in 14 patients, and was primarily successful in 12 patients. One stent occluded within the first week. All other stents were fully patent after a mean of 15 months (range, 1 to 43 months). Satisfaction was high in the patients who had the typical symptoms, but low in those who lacked them. CONCLUSION: Venous claudication and neurogenic claudication caused by venous collaterals in the spinal canal are typical clinical features of CPPVO. We recommend searching for these symptoms, because recanalization by means of stenting is often feasible and rewarding.  (+info)

Quantification of collateral flow in humans: a comparison of angiographic, electrocardiographic and hemodynamic variables. (6/1214)

OBJECTIVES: Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia. BACKGROUND: There is limited information regarding the hemodynamic quantification of recruitable collateral vessels. METHODS: Angiography of the donor coronary artery was performed before and during balloon coronary occlusion in 63 patients with one vessel disease. Patients were divided into groups of those with an absence of collateral vessels (group 1, n = 10), those with recruitable collateral vessels (group 2, n = 23) and those with spontaneously visible collateral vessels (group 3, n = 30). During balloon inflation the coronary wedge/aortic pressure ratio (Pw/Pao) was determined as were collateral blood flow velocity variables, using a 0.014" Doppler guide wire. Myocardial ischemia was defined as > or =0.1 mV ST-shift on a 12 lead electrocardiogram at 1 min coronary occlusion. RESULTS: Myocardial ischemia was present in all patients of group 1, in 14 patients of group 2 and in 3 patients of group 3. Recruitable collateral flow without ischemia showed similar hemodynamic values as in group 3 while these values were similar to group 1 in regard to the presence of recruitable collateral vessels showing ischemia. Logistic regression analysis revealed both Pw/Pao and Vi(col) as independent predictors for the function of collateral vessels. CONCLUSIONS: Hemodynamic variables of collateral vascular circulation are better markers of the functional significance of collateral vessels than is coronary angiography. The total collateral blood flow velocity integral and coronary wedge/aortic pressure ratio are good and independent predictors of the function of collateral vessels producing complementary information.  (+info)

Recovery of contractility of viable myocardium during inotropic stimulation is not dependent on an increase of myocardial blood flow in the absence of collateral filling. (7/1214)

OBJECTIVES: The purpose of this study was to determine whether contractile recovery induced by dobutamine in dysfunctioning viable myocardium supplied by nearly occluded vessels is related to an increase in blood flow in the absence of collaterals. BACKGROUND: Dobutamine is used to improve contractility in ventricular dysfunction during acute myocardial infarction. However, it is unclear whether a significant increase in regional blood flow may be involved in dobutamine effect. METHODS: Twenty patients with 5- to 10-day old anterior infarction and > or =90% left anterior descending coronary artery stenosis underwent 99mTc-Sestamibi tomography (to assess myocardial perfusion) at rest and during low dose (5 to 10 microg/kg/min) dobutamine echocardiography. Rest echocardiography and scintigraphy were repeated >1 month after revascularization. Nine patients had collaterals to the infarcted territory (group A), and 11 did not (group B). RESULTS: Baseline wall motion score was similar in both groups (score 15.9+/-1.3 vs. 17.4+/-2.0, p = NS), whereas significant changes at dobutamine and postrevascularization studies were detected (F[2,30] = 409.79, p < 0.0001). Wall motion score improved significantly (p < 0.001) in group A both at dobutamine (-5.3+/-2.2) and at postrevascularization study (-5.5+/-1.9), as well as in group B (-3.9+/-2.8 and -4.5+/-2.4, respectively). Baseline 99mTc-Sestamibi uptake was similar in both groups (62.9+/-9.7% vs. 60.3+/-10.4%, p = NS), whereas at dobutamine and postrevascularization studies a significant change (F[2,30] = 65.17, p < 0.0001) and interaction between the two groups (F[2,30] = 33.14, p < 0.0001) were present. Tracer uptake increased significantly in group A both at dobutamine (+ 10.9+/-7.9%, p < 0.001) and at postrevascularization study (12.1+/-8.7%, p < 0.001). Conversely, group B patients showed no change in tracer uptake after dobutamine test (-0.4+/-5.8, p = NS), but only after revascularization (+8.8+/-7.2%, p < 0.001). CONCLUSIONS: The increase in contractility induced by low dose dobutamine infusion in dysfunctional viable myocardium supplied by nearly occluded vessels occurs even in the absence of a significant increase in blood flow.  (+info)

Angiographic abnormalities associated with alterations in regional myocardial blood flow in coronary artery disease. (8/1214)

To evaluate the association between alterations in myocardial blood flow and angiographic findings, myocardial blood flow was compared in 26 patients with asymergy, 15 patients with a similar extent of coronary artery disease but without asynergy, and 10 patients without coronary artery disease or obvious myocardial or valvular disease. Myocardial blood flow was measured at rest with an Anger camera and PDP-11/20 computer after the intracoronary injection of 133xenon. In comparison with the normal subjects, whole heart blood flow was significantly reduced in patients with asynergy. In addition, myocardial blood flow in regions of anteroapical asynergy was reduced (85-7 +/- 7-0 ml/min per 100 g3 in controls to 65-4 +/- 4-5, P less than 0-05) and a similar reduction was noted in regions of posterolateral asymergy (91-5 +/- 8-8 in controls to 66-8 +/- 5-0, P less than 0-05). In general, regional myocardial blood flow was reduced distal to left anterior descending or left circumflex stenosis of less than 50 per cent, with a trend toward further reduction distal to less than 75 per cent stenosis. In these same patients, the presence of anteroapical or posterolateral asynergy resulted in a similar trend to even greater reduction of flow. The effect of collaterals was variable: 7 of 8 patients without asynergy but with less than 75 per cent left anterior descending stenosis and collateral circulation to the lower left anterior descending quadrant had minimally reduced flows. However, in the 17 patients with anteroapical asynergy, regional myocardial blood flow was very similar in the 9 patients with collaterals compared with the 8 patients without them. This study suggests that the degree of coronary artery stenosis and presence of asynergy are both important in evaluating alterations in myocardial blood flow in coronary artery disease, while the role of collaterals remains uncertain.  (+info)

Collateral circulation refers to the alternate blood supply routes that bypass an obstructed or narrowed vessel and reconnect with the main vascular system. These collateral vessels can develop over time as a result of the body's natural adaptation to chronic ischemia (reduced blood flow) caused by various conditions such as atherosclerosis, thromboembolism, or vasculitis.

The development of collateral circulation helps maintain adequate blood flow and oxygenation to affected tissues, minimizing the risk of tissue damage and necrosis. In some cases, well-developed collateral circulations can help compensate for significant blockages in major vessels, reducing symptoms and potentially preventing the need for invasive interventions like revascularization procedures. However, the extent and effectiveness of collateral circulation vary from person to person and depend on factors such as age, overall health status, and the presence of comorbidities.

Coronary circulation refers to the circulation of blood in the coronary vessels, which supply oxygenated blood to the heart muscle (myocardium) and drain deoxygenated blood from it. The coronary circulation system includes two main coronary arteries - the left main coronary artery and the right coronary artery - that branch off from the aorta just above the aortic valve. These arteries further divide into smaller branches, which supply blood to different regions of the heart muscle.

The left main coronary artery divides into two branches: the left anterior descending (LAD) artery and the left circumflex (LCx) artery. The LAD supplies blood to the front and sides of the heart, while the LCx supplies blood to the back and sides of the heart. The right coronary artery supplies blood to the lower part of the heart, including the right ventricle and the bottom portion of the left ventricle.

The veins that drain the heart muscle include the great cardiac vein, the middle cardiac vein, and the small cardiac vein, which merge to form the coronary sinus. The coronary sinus empties into the right atrium, allowing deoxygenated blood to enter the right side of the heart and be pumped to the lungs for oxygenation.

Coronary circulation is essential for maintaining the health and function of the heart muscle, as it provides the necessary oxygen and nutrients required for proper contraction and relaxation of the myocardium. Any disruption or blockage in the coronary circulation system can lead to serious consequences, such as angina, heart attack, or even death.

Collateral ligaments are a pair of strong bands of tissue located on the lateral (outer) and medial (inner) sides of joints, particularly in the knee and ankle. They help to stabilize and limit the side-to-side movement of the joint by preventing excessive abnormal displacement or dislocation.

In the knee, there are two collateral ligaments:

1. Medial Collateral Ligament (MCL): It runs along the inner side of the knee and connects the femur (thigh bone) to the tibia (shin bone). The MCL helps to prevent excessive inward movement or valgus stress of the knee joint.
2. Lateral Collateral Ligament (LCL): It is located on the outer side of the knee and connects the femur to the fibula (the smaller bone in the lower leg). The LCL helps to prevent excessive outward movement or varus stress of the knee joint.

In the ankle, there are also two collateral ligaments:

1. Deltoid Ligament: It is a group of ligaments located on the inner side of the ankle and connects the tibia to the talus (ankle bone) and calcaneus (heel bone). The deltoid ligament helps to prevent excessive inward movement or eversion of the ankle joint.
2. Anterior Talofibular Ligament: It is a ligament located on the outer side of the ankle, connecting the talus to the fibula. The anterior talofibular ligament helps to prevent excessive outward movement or inversion of the ankle joint.

The Circle of Willis is a circulatory arrangement in the brain where the major arteries that supply blood to the brain converge to form an almost circular structure. It is named after Thomas Willis, an English physician who first described it in 1664.

This circle is formed by the joining of the two internal carotid arteries, which divide into the anterior cerebral and middle cerebral arteries, with the basilar artery, which arises from the vertebral arteries. These vessels anastomose, or connect, to form a polygon-like structure at the base of the brain.

The Circle of Willis plays a crucial role in maintaining adequate blood flow to the brain, as it allows for collateral circulation. If one of the arteries that make up the circle becomes blocked or narrowed, blood can still reach the affected area through the other vessels in the circle. This helps to minimize the risk of stroke and other neurological disorders.

A kidney calculus, also known as a kidney stone or nephrolith, is a solid concretion or crystal aggregation that forms in the kidney from minerals in urine. These calculi can vary in size and location within the urinary tract. They can cause pain, bleeding, infection, or blockage of the urinary system if they become too large to pass through the urinary tract.

Calcium oxalate and calcium phosphate are the most common types of kidney calculi. Other less common types include uric acid stones, struvite stones, and cystine stones. The formation of kidney calculi can be influenced by various factors such as diet, dehydration, family history, medical conditions (e.g., gout, hyperparathyroidism), and certain medications.

Arterial occlusive diseases are medical conditions characterized by the blockage or narrowing of the arteries, which can lead to a reduction in blood flow to various parts of the body. This reduction in blood flow can cause tissue damage and may result in serious complications such as tissue death (gangrene), organ dysfunction, or even death.

The most common cause of arterial occlusive diseases is atherosclerosis, which is the buildup of plaque made up of fat, cholesterol, calcium, and other substances in the inner lining of the artery walls. Over time, this plaque can harden and narrow the arteries, restricting blood flow. Other causes of arterial occlusive diseases include blood clots, emboli (tiny particles that travel through the bloodstream and lodge in smaller vessels), inflammation, trauma, and certain inherited conditions.

Symptoms of arterial occlusive diseases depend on the location and severity of the blockage. Common symptoms include:

* Pain, cramping, or fatigue in the affected limb, often triggered by exercise and relieved by rest (claudication)
* Numbness, tingling, or weakness in the affected limb
* Coldness or discoloration of the skin in the affected area
* Slow-healing sores or wounds on the toes, feet, or legs
* Erectile dysfunction in men

Treatment for arterial occlusive diseases may include lifestyle changes such as quitting smoking, exercising regularly, and eating a healthy diet. Medications to lower cholesterol, control blood pressure, prevent blood clots, or manage pain may also be prescribed. In severe cases, surgical procedures such as angioplasty, stenting, or bypass surgery may be necessary to restore blood flow.

Cerebrovascular circulation refers to the network of blood vessels that supply oxygenated blood and nutrients to the brain tissue, and remove waste products. It includes the internal carotid arteries, vertebral arteries, circle of Willis, and the intracranial arteries that branch off from them.

The internal carotid arteries and vertebral arteries merge to form the circle of Willis, a polygonal network of vessels located at the base of the brain. The anterior cerebral artery, middle cerebral artery, posterior cerebral artery, and communicating arteries are the major vessels that branch off from the circle of Willis and supply blood to different regions of the brain.

Interruptions or abnormalities in the cerebrovascular circulation can lead to various neurological conditions such as stroke, transient ischemic attack (TIA), and vascular dementia.

Coronary angiography is a medical procedure that uses X-ray imaging to visualize the coronary arteries, which supply blood to the heart muscle. During the procedure, a thin, flexible catheter is inserted into an artery in the arm or groin and threaded through the blood vessels to the heart. A contrast dye is then injected through the catheter, and X-ray images are taken as the dye flows through the coronary arteries. These images can help doctors diagnose and treat various heart conditions, such as blockages or narrowing of the arteries, that can lead to chest pain or heart attacks. It is also known as coronary arteriography or cardiac catheterization.

Cerebral angiography is a medical procedure that involves taking X-ray images of the blood vessels in the brain after injecting a contrast dye into them. This procedure helps doctors to diagnose and treat various conditions affecting the blood vessels in the brain, such as aneurysms, arteriovenous malformations, and stenosis (narrowing of the blood vessels).

During the procedure, a catheter is inserted into an artery in the leg and threaded through the body to the blood vessels in the neck or brain. The contrast dye is then injected through the catheter, and X-ray images are taken to visualize the blood flow through the brain's blood vessels.

Cerebral angiography provides detailed images of the blood vessels in the brain, allowing doctors to identify any abnormalities or blockages that may be causing symptoms or increasing the risk of stroke. Based on the results of the cerebral angiography, doctors can develop a treatment plan to address these issues and prevent further complications.

Coronary occlusion is the medical term used to describe a complete blockage in one or more of the coronary arteries, which supply oxygenated blood to the heart muscle. This blockage is usually caused by the buildup of fatty deposits, called plaques, inside the artery walls, a condition known as atherosclerosis. Over time, these plaques can rupture, leading to the formation of blood clots that completely obstruct the flow of blood through the coronary artery.

Coronary occlusion can lead to serious complications, such as a heart attack (myocardial infarction), angina (chest pain), or even sudden cardiac death, depending on the severity and duration of the blockage. Immediate medical attention is required in case of coronary occlusion to restore blood flow to the affected areas of the heart and prevent further damage. Treatment options may include medications, minimally invasive procedures like angioplasty and stenting, or surgical interventions such as coronary artery bypass grafting (CABG).

Angiography is a medical procedure in which an x-ray image is taken to visualize the internal structure of blood vessels, arteries, or veins. This is done by injecting a radiopaque contrast agent (dye) into the blood vessel using a thin, flexible catheter. The dye makes the blood vessels visible on an x-ray image, allowing doctors to diagnose and treat various medical conditions such as blockages, narrowing, or malformations of the blood vessels.

There are several types of angiography, including:

* Cardiac angiography (also called coronary angiography) - used to examine the blood vessels of the heart
* Cerebral angiography - used to examine the blood vessels of the brain
* Peripheral angiography - used to examine the blood vessels in the limbs or other parts of the body.

Angiography is typically performed by a radiologist, cardiologist, or vascular surgeon in a hospital setting. It can help diagnose conditions such as coronary artery disease, aneurysms, and peripheral arterial disease, among others.

Liver circulation, also known as hepatic circulation, refers to the blood flow through the liver. The liver receives blood from two sources: the hepatic artery and the portal vein.

The hepatic artery delivers oxygenated blood from the heart to the liver, accounting for about 25% of the liver's blood supply. The remaining 75% comes from the portal vein, which carries nutrient-rich, deoxygenated blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver.

In the liver, these two sources of blood mix in the sinusoids, small vessels with large spaces between the endothelial cells that line them. This allows for efficient exchange of substances between the blood and the hepatocytes (liver cells). The blood then leaves the liver through the hepatic veins, which merge into the inferior vena cava and return the blood to the heart.

The unique dual blood supply and extensive sinusoidal network in the liver enable it to perform various critical functions, such as detoxification, metabolism, synthesis, storage, and secretion of numerous substances, maintaining body homeostasis.

Portal hypertension is a medical condition characterized by an increased pressure in the portal vein, which is the large blood vessel that carries blood from the intestines, spleen, and pancreas to the liver. Normal portal venous pressure is approximately 5-10 mmHg. Portal hypertension is defined as a portal venous pressure greater than 10 mmHg.

The most common cause of portal hypertension is cirrhosis of the liver, which leads to scarring and narrowing of the small blood vessels in the liver, resulting in increased resistance to blood flow. Other causes include blood clots in the portal vein, inflammation of the liver or bile ducts, and invasive tumors that block the flow of blood through the liver.

Portal hypertension can lead to a number of complications, including the development of abnormal blood vessels (varices) in the esophagus, stomach, and intestines, which are prone to bleeding. Ascites, or the accumulation of fluid in the abdominal cavity, is another common complication of portal hypertension. Other potential complications include encephalopathy, which is a condition characterized by confusion, disorientation, and other neurological symptoms, and an increased risk of bacterial infections.

Treatment of portal hypertension depends on the underlying cause and the severity of the condition. Medications to reduce pressure in the portal vein, such as beta blockers or nitrates, may be used. Endoscopic procedures to band or inject varices can help prevent bleeding. In severe cases, surgery or liver transplantation may be necessary.

The medial collateral ligament (MCL) of the knee is a band-like structure located on the inner side of the knee joint. It connects the end of the femur (thighbone) to the top of the tibia (shinbone) and helps stabilize the knee by controlling side-to-side movement and preventing excessive separation of the bones. The MCL provides resistance to valgus force, which is a pushing or pulling force that attempts to push the bones apart in a direction away from the midline of the body. MCL injuries often occur due to direct impact to the outer knee or sudden changes in direction that strain the ligament.

Angina pectoris is a medical term that describes chest pain or discomfort caused by an inadequate supply of oxygen-rich blood to the heart muscle. This condition often occurs due to coronary artery disease, where the coronary arteries become narrowed or blocked by the buildup of cholesterol, fatty deposits, and other substances, known as plaques. These blockages can reduce blood flow to the heart, causing ischemia (lack of oxygen) and leading to angina symptoms.

There are two primary types of angina: stable and unstable. Stable angina is predictable and usually occurs during physical exertion or emotional stress when the heart needs more oxygen-rich blood. The pain typically subsides with rest or after taking prescribed nitroglycerin medication, which helps widen the blood vessels and improve blood flow to the heart.

Unstable angina, on the other hand, is more severe and unpredictable. It can occur at rest, during sleep, or with minimal physical activity and may not be relieved by rest or nitroglycerin. Unstable angina is considered a medical emergency, as it could indicate an imminent heart attack.

Symptoms of angina pectoris include chest pain, pressure, tightness, or heaviness that typically radiates to the left arm, neck, jaw, or back. Shortness of breath, nausea, sweating, and fatigue may also accompany angina symptoms. Immediate medical attention is necessary if you experience chest pain or discomfort, especially if it's new, severe, or persistent, as it could be a sign of a more serious condition like a heart attack.

Ischemia is the medical term used to describe a lack of blood flow to a part of the body, often due to blocked or narrowed blood vessels. This can lead to a shortage of oxygen and nutrients in the tissues, which can cause them to become damaged or die. Ischemia can affect many different parts of the body, including the heart, brain, legs, and intestines. Symptoms of ischemia depend on the location and severity of the blockage, but they may include pain, cramping, numbness, weakness, or coldness in the affected area. In severe cases, ischemia can lead to tissue death (gangrene) or organ failure. Treatment for ischemia typically involves addressing the underlying cause of the blocked blood flow, such as through medication, surgery, or lifestyle changes.

Ligation, in the context of medical terminology, refers to the process of tying off a part of the body, usually blood vessels or tissue, with a surgical suture or another device. The goal is to stop the flow of fluids such as blood or other substances within the body. It is commonly used during surgeries to control bleeding or to block the passage of fluids, gases, or solids in various parts of the body.

Pathological constriction refers to an abnormal narrowing or tightening of a body passage or organ, which can interfere with the normal flow of blood, air, or other substances through the area. This constriction can occur due to various reasons such as inflammation, scarring, or abnormal growths, and can affect different parts of the body, including blood vessels, airways, intestines, and ureters. Pathological constriction can lead to a range of symptoms and complications depending on its location and severity, and may require medical intervention to correct.

Balloon occlusion is a medical procedure that involves the use of a small, deflated balloon at the end of a catheter, which can be inserted into a blood vessel or other tubular structure in the body. Once the balloon is in position, it is inflated with a fluid or gas to create a blockage or obstruction in the vessel. This can be used for various medical purposes, such as:

1. Controlling bleeding: By inflating the balloon in a blood vessel, doctors can temporarily stop the flow of blood to a specific area, allowing them to treat injuries or abnormalities that are causing excessive bleeding.
2. Vessel narrowing or blockage assessment: Balloon occlusion can be used to assess the severity of narrowing or blockages in blood vessels. By inflating the balloon and measuring the pressure differences upstream and downstream, doctors can determine the extent of the obstruction and plan appropriate treatment.
3. Embolization therapy: In some cases, balloon occlusion is used to deliver embolic agents (such as coils, particles, or glue) that block off blood flow to specific areas. This can be useful in treating conditions like tumors, arteriovenous malformations, or aneurysms.
4. Temporary vessel occlusion during surgery: During certain surgical procedures, it may be necessary to temporarily stop the flow of blood to a specific area. Balloon occlusion can be used to achieve this quickly and safely.
5. Assisting in the placement of stents or other devices: Balloon occlusion can help position and deploy stents or other medical devices by providing temporary support or blocking off blood flow during the procedure.

It is important to note that balloon occlusion procedures carry potential risks, such as vessel injury, infection, or embolism (the blockage of a blood vessel by a clot or foreign material). These risks should be carefully weighed against the benefits when considering this type of treatment.

Coronary vessels refer to the network of blood vessels that supply oxygenated blood and nutrients to the heart muscle, also known as the myocardium. The two main coronary arteries are the left main coronary artery and the right coronary artery.

The left main coronary artery branches off into the left anterior descending artery (LAD) and the left circumflex artery (LCx). The LAD supplies blood to the front of the heart, while the LCx supplies blood to the side and back of the heart.

The right coronary artery supplies blood to the right lower part of the heart, including the right atrium and ventricle, as well as the back of the heart.

Coronary vessel disease (CVD) occurs when these vessels become narrowed or blocked due to the buildup of plaque, leading to reduced blood flow to the heart muscle. This can result in chest pain, shortness of breath, or a heart attack.

Regional blood flow (RBF) refers to the rate at which blood flows through a specific region or organ in the body, typically expressed in milliliters per minute per 100 grams of tissue (ml/min/100g). It is an essential physiological parameter that reflects the delivery of oxygen and nutrients to tissues while removing waste products. RBF can be affected by various factors such as metabolic demands, neural regulation, hormonal influences, and changes in blood pressure or vascular resistance. Measuring RBF is crucial for understanding organ function, diagnosing diseases, and evaluating the effectiveness of treatments.

Coronary artery disease, often simply referred to as coronary disease, is a condition in which the blood vessels that supply oxygen-rich blood to the heart become narrowed or blocked due to the buildup of fatty deposits called plaques. This can lead to chest pain (angina), shortness of breath, or in severe cases, a heart attack.

The medical definition of coronary artery disease is:

A condition characterized by the accumulation of atheromatous plaques in the walls of the coronary arteries, leading to decreased blood flow and oxygen supply to the myocardium (heart muscle). This can result in symptoms such as angina pectoris, shortness of breath, or arrhythmias, and may ultimately lead to myocardial infarction (heart attack) or heart failure.

Risk factors for coronary artery disease include age, smoking, high blood pressure, high cholesterol, diabetes, obesity, physical inactivity, and a family history of the condition. Lifestyle changes such as quitting smoking, exercising regularly, eating a healthy diet, and managing stress can help reduce the risk of developing coronary artery disease. Medical treatments may include medications to control blood pressure, cholesterol levels, or irregular heart rhythms, as well as procedures such as angioplasty or bypass surgery to improve blood flow to the heart.

Blood flow velocity is the speed at which blood travels through a specific part of the vascular system. It is typically measured in units of distance per time, such as centimeters per second (cm/s) or meters per second (m/s). Blood flow velocity can be affected by various factors, including cardiac output, vessel diameter, and viscosity of the blood. Measuring blood flow velocity is important in diagnosing and monitoring various medical conditions, such as heart disease, stroke, and peripheral vascular disease.

Magnetic Resonance Angiography (MRA) is a non-invasive medical imaging technique that uses magnetic fields and radio waves to create detailed images of the blood vessels or arteries within the body. It is a type of Magnetic Resonance Imaging (MRI) that focuses specifically on the circulatory system.

MRA can be used to diagnose and evaluate various conditions related to the blood vessels, such as aneurysms, stenosis (narrowing of the vessel), or the presence of plaques or tumors. It can also be used to plan for surgeries or other treatments related to the vascular system. The procedure does not use radiation and is generally considered safe, although people with certain implants like pacemakers may not be able to have an MRA due to safety concerns.

Cineangiography is a medical imaging technique used to visualize the blood flow in the heart and cardiovascular system. It involves the injection of a contrast agent into the bloodstream while X-ray images are taken in quick succession, creating a movie-like sequence that shows the movement of the contrast through the blood vessels and chambers of the heart. This technique is often used to diagnose and evaluate various heart conditions, such as coronary artery disease, valvular heart disease, and congenital heart defects.

The procedure typically involves threading a catheter through a blood vessel in the arm or leg and guiding it to the heart. Once in place, the contrast agent is injected, and X-ray images are taken using a specialized X-ray machine called a fluoroscope. The images captured during cineangiography can help doctors identify areas of narrowing or blockage in the coronary arteries, abnormalities in heart valves, and other cardiovascular problems.

Cineangiography is an invasive procedure that carries some risks, such as bleeding, infection, and reactions to the contrast agent. However, it can provide valuable information for diagnosing and treating heart conditions, and may be recommended when other diagnostic tests have been inconclusive.

The internal carotid artery is a major blood vessel that supplies oxygenated blood to the brain. It originates from the common carotid artery and passes through the neck, entering the skull via the carotid canal in the temporal bone. Once inside the skull, it branches into several smaller vessels that supply different parts of the brain with blood.

The internal carotid artery is divided into several segments: cervical, petrous, cavernous, clinoid, and supraclinoid. Each segment has distinct clinical significance in terms of potential injury or disease. The most common conditions affecting the internal carotid artery include atherosclerosis, which can lead to stroke or transient ischemic attack (TIA), and dissection, which can cause severe headache, neck pain, and neurological symptoms.

It's important to note that any blockage or damage to the internal carotid artery can have serious consequences, as it can significantly reduce blood flow to the brain and lead to permanent neurological damage or even death. Therefore, regular check-ups and screening tests are recommended for individuals at high risk of developing vascular diseases.

The celiac artery, also known as the anterior abdominal aortic trunk, is a major artery that originates from the abdominal aorta and supplies oxygenated blood to the foregut, which includes the stomach, liver, spleen, pancreas, and upper part of the duodenum. It branches into three main branches: the left gastric artery, the splenic artery, and the common hepatic artery. The celiac artery plays a crucial role in providing blood to these vital organs, and any disruption or damage to it can lead to serious health consequences.

Blood circulation, also known as cardiovascular circulation, refers to the process by which blood is pumped by the heart and circulated throughout the body through a network of blood vessels, including arteries, veins, and capillaries. This process ensures that oxygen and nutrients are delivered to cells and tissues, while waste products and carbon dioxide are removed.

The circulation of blood can be divided into two main parts: the pulmonary circulation and the systemic circulation. The pulmonary circulation involves the movement of blood between the heart and the lungs, where it picks up oxygen and releases carbon dioxide. The systemic circulation refers to the movement of blood between the heart and the rest of the body, delivering oxygen and nutrients to cells and tissues while picking up waste products for removal.

The heart plays a central role in blood circulation, acting as a pump that contracts and relaxes to move blood through the body. The contraction of the heart's left ventricle pushes oxygenated blood into the aorta, which then branches off into smaller arteries that carry blood throughout the body. The blood then flows through capillaries, where it exchanges oxygen and nutrients for waste products and carbon dioxide with surrounding cells and tissues. The deoxygenated blood is then collected in veins, which merge together to form larger vessels that eventually return the blood back to the heart's right atrium. From there, the blood is pumped into the lungs to pick up oxygen and release carbon dioxide, completing the cycle of blood circulation.

Cerebral arteries refer to the blood vessels that supply oxygenated blood to the brain. These arteries branch off from the internal carotid arteries and the vertebral arteries, which combine to form the basilar artery. The major cerebral arteries include:

1. Anterior cerebral artery (ACA): This artery supplies blood to the frontal lobes of the brain, including the motor and sensory cortices responsible for movement and sensation in the lower limbs.
2. Middle cerebral artery (MCA): The MCA is the largest of the cerebral arteries and supplies blood to the lateral surface of the brain, including the temporal, parietal, and frontal lobes. It is responsible for providing blood to areas involved in motor function, sensory perception, speech, memory, and vision.
3. Posterior cerebral artery (PCA): The PCA supplies blood to the occipital lobe, which is responsible for visual processing, as well as parts of the temporal and parietal lobes.
4. Anterior communicating artery (ACoA) and posterior communicating arteries (PComAs): These are small arteries that connect the major cerebral arteries, forming an important circulatory network called the Circle of Willis. The ACoA connects the two ACAs, while the PComAs connect the ICA with the PCA and the basilar artery.

These cerebral arteries play a crucial role in maintaining proper brain function by delivering oxygenated blood to various regions of the brain. Any damage or obstruction to these arteries can lead to serious neurological conditions, such as strokes or transient ischemic attacks (TIAs).

Coronary balloon angioplasty is a minimally invasive medical procedure used to widen narrowed or obstructed coronary arteries (the blood vessels that supply oxygen-rich blood to the heart muscle) and improve blood flow to the heart. This procedure is typically performed in conjunction with the insertion of a stent, a small mesh tube that helps keep the artery open.

During coronary balloon angioplasty, a thin, flexible catheter with a deflated balloon at its tip is inserted into a blood vessel, usually through a small incision in the groin or arm. The catheter is then guided to the narrowed or obstructed section of the coronary artery. Once in position, the balloon is inflated to compress the plaque against the artery wall and widen the lumen (the inner space) of the artery. This helps restore blood flow to the heart muscle.

The procedure is typically performed under local anesthesia and conscious sedation to minimize discomfort. Coronary balloon angioplasty is a relatively safe and effective treatment for many people with coronary artery disease, although complications such as bleeding, infection, or re-narrowing of the artery (restenosis) can occur in some cases.

The Doppler effect, also known as the Doppler shift, is a change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave. It was first described by Austrian physicist Christian Doppler in 1842.

In the context of medical ultrasound, the Doppler effect is used to measure the velocity of blood flow in the body. When the ultrasound waves encounter moving red blood cells, the frequency of the reflected waves changes due to the Doppler effect. This change in frequency can be used to calculate the speed and direction of blood flow.

Doppler ultrasound is commonly used in medical imaging to assess conditions such as heart valve function, blood clots, and narrowed or blocked blood vessels. It can also be used to monitor fetal heart rate and blood flow during pregnancy.

Cerebral arterial diseases refer to conditions that affect the blood vessels supplying the brain. These diseases can result in reduced blood flow, blockages, or bleeding in the brain. The most common cerebral arterial diseases include:

1. Atherosclerosis: A buildup of plaque made up of fat, cholesterol, and other substances in the inner lining of an artery, which can lead to narrowing or blockage of the artery.
2. Embolism: A blood clot or other particle that forms elsewhere in the body and travels to the brain, where it blocks a cerebral artery.
3. Thrombosis: The formation of a blood clot within a cerebral artery.
4. Aneurysm: A weakened area in the wall of an artery that bulges out and can rupture, causing bleeding in the brain.
5. Arteriovenous malformation (AVM): An abnormal tangle of blood vessels in the brain that can cause bleeding or reduced blood flow to surrounding tissue.
6. Vasculitis: Inflammation of the blood vessels in the brain, which can lead to narrowing, blockage, or weakening of the vessel walls.

These conditions can lead to serious complications such as stroke, transient ischemic attack (TIA), or vascular dementia. Treatment options include medications, surgery, and lifestyle changes to manage risk factors.

Coronary stenosis is a medical condition that refers to the narrowing of the coronary arteries, which supply oxygen-rich blood to the heart muscle. This narrowing is typically caused by the buildup of plaque, made up of fat, cholesterol, and other substances, on the inner walls of the arteries. Over time, as the plaque hardens and calcifies, it can cause the artery to become narrowed or blocked, reducing blood flow to the heart muscle.

Coronary stenosis can lead to various symptoms and complications, including chest pain (angina), shortness of breath, irregular heart rhythms (arrhythmias), and heart attacks. Treatment options for coronary stenosis may include lifestyle changes, medications, medical procedures such as angioplasty or bypass surgery, or a combination of these approaches. Regular check-ups and diagnostic tests, such as stress testing or coronary angiography, can help detect and monitor coronary stenosis over time.

A hindlimb, also known as a posterior limb, is one of the pair of extremities that are located distally to the trunk in tetrapods (four-legged vertebrates) and include mammals, birds, reptiles, and amphibians. In humans and other primates, hindlimbs are equivalent to the lower limbs, which consist of the thigh, leg, foot, and toes.

The primary function of hindlimbs is locomotion, allowing animals to move from one place to another. However, they also play a role in other activities such as balance, support, and communication. In humans, the hindlimbs are responsible for weight-bearing, standing, walking, running, and jumping.

In medical terminology, the term "hindlimb" is not commonly used to describe human anatomy. Instead, healthcare professionals use terms like lower limbs or lower extremities to refer to the same region of the body. However, in comparative anatomy and veterinary medicine, the term hindlimb is still widely used to describe the corresponding structures in non-human animals.

The femoral artery is the major blood vessel that supplies oxygenated blood to the lower extremity of the human body. It is a continuation of the external iliac artery and becomes the popliteal artery as it passes through the adductor hiatus in the adductor magnus muscle of the thigh.

The femoral artery is located in the femoral triangle, which is bound by the sartorius muscle anteriorly, the adductor longus muscle medially, and the biceps femoris muscle posteriorly. It can be easily palpated in the groin region, making it a common site for taking blood samples, measuring blood pressure, and performing surgical procedures such as femoral artery catheterization and bypass grafting.

The femoral artery gives off several branches that supply blood to the lower limb, including the deep femoral artery, the superficial femoral artery, and the profunda femoris artery. These branches provide blood to the muscles, bones, skin, and other tissues of the leg, ankle, and foot.

Moyamoya Disease is a rare, progressive cerebrovascular disorder characterized by the narrowing or occlusion (blockage) of the internal carotid artery and its main branches. The name "moyamoya" means "puff of smoke" in Japanese and describes the look of the tangle of tiny vessels formed to compensate for the blockage. Over time, these fragile vessels can become less effective or rupture, leading to transient ischemic attacks (mini-strokes), strokes, bleeding in the brain, or cognitive decline. The exact cause of moyamoya disease is unknown, but it may be associated with genetic factors and certain medical conditions such as Down syndrome, neurofibromatosis type 1, and sickle cell anemia. Treatment options include surgical procedures to improve blood flow to the brain.

Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.

The external carotid artery is a major blood vessel in the neck that supplies oxygenated blood to the structures of the head and neck, excluding the brain. It originates from the common carotid artery at the level of the upper border of the thyroid cartilage, then divides into several branches that supply various regions of the head and neck, including the face, scalp, ears, and neck muscles.

The external carotid artery has eight branches:

1. Superior thyroid artery: Supplies blood to the thyroid gland, larynx, and surrounding muscles.
2. Ascending pharyngeal artery: Supplies blood to the pharynx, palate, and meninges of the brain.
3. Lingual artery: Supplies blood to the tongue and floor of the mouth.
4. Facial artery: Supplies blood to the face, nose, lips, and palate.
5. Occipital artery: Supplies blood to the scalp and muscles of the neck.
6. Posterior auricular artery: Supplies blood to the ear and surrounding muscles.
7. Maxillary artery: Supplies blood to the lower face, nasal cavity, palate, and meninges of the brain.
8. Superficial temporal artery: Supplies blood to the scalp, face, and temporomandibular joint.

The external carotid artery is an essential structure for maintaining adequate blood flow to the head and neck, and any damage or blockage can lead to serious medical conditions such as stroke or tissue necrosis.

Myocardial infarction (MI), also known as a heart attack, is a medical condition characterized by the death of a segment of heart muscle (myocardium) due to the interruption of its blood supply. This interruption is most commonly caused by the blockage of a coronary artery by a blood clot formed on the top of an atherosclerotic plaque, which is a buildup of cholesterol and other substances in the inner lining of the artery.

The lack of oxygen and nutrients supply to the heart muscle tissue results in damage or death of the cardiac cells, causing the affected area to become necrotic. The extent and severity of the MI depend on the size of the affected area, the duration of the occlusion, and the presence of collateral circulation.

Symptoms of a myocardial infarction may include chest pain or discomfort, shortness of breath, nausea, lightheadedness, and sweating. Immediate medical attention is necessary to restore blood flow to the affected area and prevent further damage to the heart muscle. Treatment options for MI include medications, such as thrombolytics, antiplatelet agents, and pain relievers, as well as procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Physiologic neovascularization is the natural and controlled formation of new blood vessels in the body, which occurs as a part of normal growth and development, as well as in response to tissue repair and wound healing. This process involves the activation of endothelial cells, which line the interior surface of blood vessels, and their migration, proliferation, and tube formation to create new capillaries. Physiologic neovascularization is tightly regulated by a balance of pro-angiogenic and anti-angiogenic factors, ensuring that it occurs only when and where it is needed. It plays crucial roles in various physiological processes, such as embryonic development, tissue regeneration, and wound healing.

Digital subtraction angiography (DSA) is a medical imaging technique used to visualize the blood vessels and blood flow within the body. It combines the use of X-ray technology with digital image processing to produce detailed images of the vascular system.

In DSA, a contrast agent is injected into the patient's bloodstream through a catheter, which is typically inserted into an artery in the leg and guided to the area of interest using fluoroscopy. As the contrast agent flows through the blood vessels, X-ray images are taken at multiple time points.

The digital subtraction process involves taking a baseline image without contrast and then subtracting it from subsequent images taken with contrast. This allows for the removal of background structures and noise, resulting in clearer images of the blood vessels. DSA can be used to diagnose and evaluate various vascular conditions, such as aneurysms, stenosis, and tumors, and can also guide interventional procedures such as angioplasty and stenting.

Carotid stenosis is a medical condition that refers to the narrowing or constriction of the lumen (inner space) of the carotid artery. The carotid arteries are major blood vessels that supply oxygenated blood to the head and neck. Carotid stenosis usually results from the buildup of plaque, made up of fat, cholesterol, calcium, and other substances, on the inner walls of the artery. This process is called atherosclerosis.

As the plaque accumulates, it causes the artery to narrow, reducing blood flow to the brain. Severe carotid stenosis can increase the risk of stroke, as a clot or debris from the plaque can break off and travel to the brain, blocking a smaller blood vessel and causing tissue damage or death.

Carotid stenosis is typically diagnosed through imaging tests such as ultrasound, CT angiography, or MRI angiography. Treatment options may include lifestyle modifications (such as quitting smoking, controlling blood pressure, and managing cholesterol levels), medications to reduce the risk of clots, or surgical procedures like endarterectomy or stenting to remove or bypass the blockage.

Myocardial ischemia is a condition in which the blood supply to the heart muscle (myocardium) is reduced or blocked, leading to insufficient oxygen delivery and potential damage to the heart tissue. This reduction in blood flow typically results from the buildup of fatty deposits, called plaques, in the coronary arteries that supply the heart with oxygen-rich blood. The plaques can rupture or become unstable, causing the formation of blood clots that obstruct the artery and limit blood flow.

Myocardial ischemia may manifest as chest pain (angina pectoris), shortness of breath, fatigue, or irregular heartbeats (arrhythmias). In severe cases, it can lead to myocardial infarction (heart attack) if the oxygen supply is significantly reduced or cut off completely, causing permanent damage or death of the heart muscle. Early diagnosis and treatment of myocardial ischemia are crucial for preventing further complications and improving patient outcomes.

Brain ischemia is the medical term used to describe a reduction or interruption of blood flow to the brain, leading to a lack of oxygen and glucose delivery to brain tissue. This can result in brain damage or death of brain cells, known as infarction. Brain ischemia can be caused by various conditions such as thrombosis (blood clot formation), embolism (obstruction of a blood vessel by a foreign material), or hypoperfusion (reduced blood flow). The severity and duration of the ischemia determine the extent of brain damage. Symptoms can range from mild, such as transient ischemic attacks (TIAs or "mini-strokes"), to severe, including paralysis, speech difficulties, loss of consciousness, and even death. Immediate medical attention is required for proper diagnosis and treatment to prevent further damage and potential long-term complications.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

Electrocardiography (ECG or EKG) is a medical procedure that records the electrical activity of the heart. It provides a graphic representation of the electrical changes that occur during each heartbeat. The resulting tracing, called an electrocardiogram, can reveal information about the heart's rate and rhythm, as well as any damage to its cells or abnormalities in its conduction system.

During an ECG, small electrodes are placed on the skin of the chest, arms, and legs. These electrodes detect the electrical signals produced by the heart and transmit them to a machine that amplifies and records them. The procedure is non-invasive, painless, and quick, usually taking only a few minutes.

ECGs are commonly used to diagnose and monitor various heart conditions, including arrhythmias, coronary artery disease, heart attacks, and electrolyte imbalances. They can also be used to evaluate the effectiveness of certain medications or treatments.

Middle Cerebral Artery (MCA) infarction is a type of ischemic stroke that occurs when there is an obstruction in the blood supply to the middle cerebral artery, which is one of the major blood vessels that supplies oxygenated blood to the brain. The MCA supplies blood to a large portion of the brain, including the motor and sensory cortex, parts of the temporal and parietal lobes, and the basal ganglia.

An infarction is the death of tissue due to the lack of blood supply, which can lead to damage or loss of function in the affected areas of the brain. Symptoms of MCA infarction may include weakness or numbness on one side of the body, difficulty speaking or understanding speech, vision problems, and altered levels of consciousness.

MCA infarctions can be caused by various factors, including embolism (a blood clot that travels to the brain from another part of the body), thrombosis (a blood clot that forms in the MCA itself), or stenosis (narrowing of the artery due to atherosclerosis or other conditions). Treatment for MCA infarction may include medications to dissolve blood clots, surgery to remove the obstruction, or rehabilitation to help regain lost function.

Phlebography is a medical imaging technique used to visualize and assess the veins, particularly in the legs. It involves the injection of a contrast agent into the veins, followed by X-ray imaging to capture the flow of the contrast material through the veins. This allows doctors to identify any abnormalities such as blood clots, blockages, or malformations in the venous system.

There are different types of phlebography, including ascending phlebography (where the contrast agent is injected into a foot vein and travels up the leg) and descending phlebography (where the contrast agent is injected into a vein in the groin or neck and travels down the leg).

Phlebography is an invasive procedure that requires careful preparation and monitoring, and it is typically performed by radiologists or vascular specialists. It has largely been replaced by non-invasive imaging techniques such as ultrasound and CT angiography in many clinical settings.

Cardiac catheterization is a medical procedure used to diagnose and treat cardiovascular conditions. In this procedure, a thin, flexible tube called a catheter is inserted into a blood vessel in the arm or leg and threaded up to the heart. The catheter can be used to perform various diagnostic tests, such as measuring the pressure inside the heart chambers and assessing the function of the heart valves.

Cardiac catheterization can also be used to treat certain cardiovascular conditions, such as narrowed or blocked arteries. In these cases, a balloon or stent may be inserted through the catheter to open up the blood vessel and improve blood flow. This procedure is known as angioplasty or percutaneous coronary intervention (PCI).

Cardiac catheterization is typically performed in a hospital cardiac catheterization laboratory by a team of healthcare professionals, including cardiologists, radiologists, and nurses. The procedure may be done under local anesthesia with sedation or general anesthesia, depending on the individual patient's needs and preferences.

Overall, cardiac catheterization is a valuable tool in the diagnosis and treatment of various heart conditions, and it can help improve symptoms, reduce complications, and prolong life for many patients.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Therapeutic embolization is a medical procedure that involves intentionally blocking or obstructing blood vessels to stop excessive bleeding or block the flow of blood to a tumor or abnormal tissue. This is typically accomplished by injecting small particles, such as microspheres or coils, into the targeted blood vessel through a catheter, which is inserted into a larger blood vessel and guided to the desired location using imaging techniques like X-ray or CT scanning. The goal of therapeutic embolization is to reduce the size of a tumor, control bleeding, or block off abnormal blood vessels that are causing problems.

Arteries are blood vessels that carry oxygenated blood away from the heart to the rest of the body. They have thick, muscular walls that can withstand the high pressure of blood being pumped out of the heart. Arteries branch off into smaller vessels called arterioles, which further divide into a vast network of tiny capillaries where the exchange of oxygen, nutrients, and waste occurs between the blood and the body's cells. After passing through the capillary network, deoxygenated blood collects in venules, then merges into veins, which return the blood back to the heart.

Cerebral infarction, also known as a "stroke" or "brain attack," is the sudden death of brain cells caused by the interruption of their blood supply. It is most commonly caused by a blockage in one of the blood vessels supplying the brain (an ischemic stroke), but can also result from a hemorrhage in or around the brain (a hemorrhagic stroke).

Ischemic strokes occur when a blood clot or other particle blocks a cerebral artery, cutting off blood flow to a part of the brain. The lack of oxygen and nutrients causes nearby brain cells to die. Hemorrhagic strokes occur when a weakened blood vessel ruptures, causing bleeding within or around the brain. This bleeding can put pressure on surrounding brain tissues, leading to cell death.

Symptoms of cerebral infarction depend on the location and extent of the affected brain tissue but may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; and severe headache with no known cause. Immediate medical attention is crucial for proper diagnosis and treatment to minimize potential long-term damage or disability.

Extracorporeal circulation (ECC) is a term used in medicine to describe the process of temporarily taking over the functions of the heart and lungs by using a machine. This allows the surgeon to perform certain types of surgery, such as open-heart surgery, on a still and bloodless operating field.

During ECC, the patient's blood is circulated outside the body through a pump and oxygenator. The pump helps to maintain blood flow and pressure, while the oxygenator adds oxygen to the blood and removes carbon dioxide. This allows the surgeon to stop the heart and arrest its motion, making it easier to perform delicate procedures on the heart and surrounding structures.

Extracorporeal circulation is a complex and high-risk procedure that requires careful monitoring and management by a team of healthcare professionals. It carries risks such as bleeding, infection, and injury to blood vessels or organs. However, when performed correctly, it can be a life-saving measure for patients undergoing certain types of surgery.

Pulmonary circulation refers to the process of blood flow through the lungs, where blood picks up oxygen and releases carbon dioxide. This is a vital part of the overall circulatory system, which delivers nutrients and oxygen to the body's cells while removing waste products like carbon dioxide.

In pulmonary circulation, deoxygenated blood from the systemic circulation returns to the right atrium of the heart via the superior and inferior vena cava. The blood then moves into the right ventricle through the tricuspid valve and gets pumped into the pulmonary artery when the right ventricle contracts.

The pulmonary artery divides into smaller vessels called arterioles, which further branch into a vast network of tiny capillaries in the lungs. Here, oxygen from the alveoli diffuses into the blood, binding to hemoglobin in red blood cells, while carbon dioxide leaves the blood and is exhaled through the nose or mouth.

The now oxygenated blood collects in venules, which merge to form pulmonary veins. These veins transport the oxygen-rich blood back to the left atrium of the heart, where it enters the systemic circulation once again. This continuous cycle enables the body's cells to receive the necessary oxygen and nutrients for proper functioning while disposing of waste products.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Coronary artery disease (CAD) is a medical condition in which the coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of cholesterol, fatty deposits, and other substances, known as plaque. Over time, this buildup can cause the arteries to harden and narrow (a process called atherosclerosis), reducing blood flow to the heart muscle.

The reduction in blood flow can lead to various symptoms and complications, including:

1. Angina (chest pain or discomfort) - This occurs when the heart muscle doesn't receive enough oxygen-rich blood, causing pain, pressure, or discomfort in the chest, arms, neck, jaw, or back.
2. Shortness of breath - When the heart isn't receiving adequate blood flow, it can't pump blood efficiently to meet the body's demands, leading to shortness of breath during physical activities or at rest.
3. Heart attack - If a piece of plaque ruptures or breaks off in a coronary artery, a blood clot can form and block the artery, causing a heart attack (myocardial infarction). This can damage or destroy part of the heart muscle.
4. Heart failure - Chronic reduced blood flow to the heart muscle can weaken it over time, leading to heart failure, a condition in which the heart can't pump blood efficiently to meet the body's needs.
5. Arrhythmias - Reduced blood flow and damage to the heart muscle can lead to abnormal heart rhythms (arrhythmias), which can be life-threatening if not treated promptly.

Coronary artery disease is typically diagnosed through a combination of medical history, physical examination, and diagnostic tests such as electrocardiograms (ECGs), stress testing, cardiac catheterization, and imaging studies like coronary computed tomography angiography (CCTA). Treatment options for CAD include lifestyle modifications, medications, medical procedures, and surgery.

Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:

1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.

Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.

Carotid artery diseases refer to conditions that affect the carotid arteries, which are the major blood vessels that supply oxygen-rich blood to the head and neck. The most common type of carotid artery disease is atherosclerosis, which occurs when fatty deposits called plaques build up in the inner lining of the arteries.

These plaques can cause the arteries to narrow or become blocked, reducing blood flow to the brain and increasing the risk of stroke. Other carotid artery diseases include carotid artery dissection, which occurs when there is a tear in the inner lining of the artery, and fibromuscular dysplasia, which is a condition that affects the muscle and tissue in the walls of the artery.

Symptoms of carotid artery disease may include neck pain or pulsations, transient ischemic attacks (TIAs) or "mini-strokes," and strokes. Treatment options for carotid artery disease depend on the severity and type of the condition but may include lifestyle changes, medications, endarterectomy (a surgical procedure to remove plaque from the artery), or angioplasty and stenting (procedures to open blocked arteries using a balloon and stent).

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

The carotid arteries are a pair of vital blood vessels in the human body that supply oxygenated blood to the head and neck. Each person has two common carotid arteries, one on each side of the neck, which branch off from the aorta, the largest artery in the body.

The right common carotid artery originates from the brachiocephalic trunk, while the left common carotid artery arises directly from the aortic arch. As they ascend through the neck, they split into two main branches: the internal and external carotid arteries.

The internal carotid artery supplies oxygenated blood to the brain, eyes, and other structures within the skull, while the external carotid artery provides blood to the face, scalp, and various regions of the neck.

Maintaining healthy carotid arteries is crucial for overall cardiovascular health and preventing serious conditions like stroke, which can occur when the arteries become narrowed or blocked due to the buildup of plaque or fatty deposits (atherosclerosis). Regular check-ups with healthcare professionals may include monitoring carotid artery health through ultrasound or other imaging techniques.

A stroke, also known as cerebrovascular accident (CVA), is a serious medical condition that occurs when the blood supply to part of the brain is interrupted or reduced, leading to deprivation of oxygen and nutrients to brain cells. This can result in the death of brain tissue and cause permanent damage or temporary impairment to cognitive functions, speech, memory, movement, and other body functions controlled by the affected area of the brain.

Strokes can be caused by either a blockage in an artery that supplies blood to the brain (ischemic stroke) or the rupture of a blood vessel in the brain (hemorrhagic stroke). A transient ischemic attack (TIA), also known as a "mini-stroke," is a temporary disruption of blood flow to the brain that lasts only a few minutes and does not cause permanent damage.

Symptoms of a stroke may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; severe headache with no known cause; and confusion or disorientation. Immediate medical attention is crucial for stroke patients to receive appropriate treatment and prevent long-term complications.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Follow-up studies are a type of longitudinal research that involve repeated observations or measurements of the same variables over a period of time, in order to understand their long-term effects or outcomes. In medical context, follow-up studies are often used to evaluate the safety and efficacy of medical treatments, interventions, or procedures.

In a typical follow-up study, a group of individuals (called a cohort) who have received a particular treatment or intervention are identified and then followed over time through periodic assessments or data collection. The data collected may include information on clinical outcomes, adverse events, changes in symptoms or functional status, and other relevant measures.

The results of follow-up studies can provide important insights into the long-term benefits and risks of medical interventions, as well as help to identify factors that may influence treatment effectiveness or patient outcomes. However, it is important to note that follow-up studies can be subject to various biases and limitations, such as loss to follow-up, recall bias, and changes in clinical practice over time, which must be carefully considered when interpreting the results.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

... portocaval collateral circulation). collateral circulation (Articles with short description, Short description ... Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor ... It is occasionally also known as accessory circulation, auxiliary circulation, or secondary circulation. It has surgically ... Collateral circulation is created (within months) around the blocked central vein via a generally winding path, usually from a ...
The leptomeningeal collateral circulation (also known as leptomeningeal anastomoses or pial collaterals) is a network of small ... There is anatomical variation in collateral circulation from person to person, and as we age, collateral vessels decrease in ... Coyle, Peter (1994). "Collateral Pial Arteries". In Bevan, Rosemary D.; Bevan, John A. (eds.). The Human Brain Circulation. pp ... Therapies that attempt to optimize leptomeningeal collateral circulation appear to improve outcomes following acute ischaemic ...
Liebeskind DS (September 2003). "Collateral circulation". Stroke. 34 (9): 2279-2284. doi:10.1161/01.STR.0000086465.41263.06. ... as the bilateral circulation continues perfusing the brain. Thrombus formation is the natural physiologic response to the ...
Meier P, Schirmer SH, Lansky AJ, Timmis A, Pitt B, Seiler C (June 2013). "The collateral circulation of the heart". BMC Med. 11 ... It was only in 1931 that they were acknowledged as acting as collaterals, and the term collateral respiration was first used. ... Mitzner, W. (1 January 2006). "Ventilation , Collateral". Ventilation , Collateral. pp. 434-438. doi:10.1016/B0-12-370879-6/ ... Collateral ventilation is not present in horses who have a poor tolerance to airway obstruction but it is present in dogs who ...
This is known as collateral circulation. The saphenous nerve that runs with the upper part of the great saphenous vein is a ... Removal of the saphenous vein will not materially hinder normal circulation in the leg. The blood that previously flowed ... a clot fragment can migrate to the deep venous system and to the pulmonary circulation. Also it can be associated with, or ...
with A. Morgan Jones: Bramwell, C.; Jones, A. M. (October 1941). "Coarctation of the aorta: the collateral circulation". Br. ... and to the features of the circulation in athletes are well known. J. Crighton Bramwell's father Byrom Bramwell and eldest ...
"The collateral arterial circulation in the pelvis. An angiographic study". American Journal of Roentgenology. 102 (2): 392-400 ...
Leptomeningeal collateral circulation Moore KL, Dalley AR. Clinically Oriented Anatomy, 4th Ed., Lippincott Williams & Wilkins ...
The radial artery is also used to evaluate the collateral circulation of blood through the hands; applying pressure through ... adequate collateral circulation can be ascertained by how quickly normal colour returns after the pressure is removed. The ... "Evaluation of collateral circulation of the hand". Journal of Clinical Monitoring. 8 (1): 28-32. doi:10.1007/BF01618084. ISSN ... It travels superiorly to anastomose with the radial collateral artery around the elbow joint Palmar carpal branch of radial ...
... so there is potential for collateral circulation here. The venous drainage of the duodenum follows the arteries. Ultimately ...
Fishman AP (September 1961). "The clinical significance of the pulmonary collateral circulation". Circulation. American Heart ... Largely for this reason, bronchial artery circulation is usually sacrificed during lung transplants, instead relying on the ... persistence of a microcirculation (presumably arising from the deoxygenated pulmonary circulation) to provide perfusion to the ...
The result may be the development of collateral circulation. Tetralogy of Fallot (ToF) Total anomalous pulmonary venous ... Mathematical models are used to address the issue of pressure level alterations of circulation after the procedures. The ... or a mixture of oxygenated and unoxygenated blood entering the systemic circulation. It is caused by structural defects of the ... and these models permit clear analyses of the pressure increase allowing doctors to avoid possible venous circulation ...
Stead, SW; Stirt, JA (1985). "Assessment of digital blood flow and palmar collateral circulation". Journal of Clinical ... Allen's test looks for abnormal circulation. If color returns quickly as described above, Allen's test is considered to ... demonstrate normal circulation. If the pallor persists for some time after the patient opens their fingers, this suggests a ...
Collateral circulation gives "tree root" or "spider leg" appearance. Angiograms may also show occlusions (blockages) or ... The main symptom is pain in the affected areas, at rest and while walking (claudication). The impaired circulation increases ... The king's doctors prescribed complete rest and electric treatment to stimulate circulation, but as they were either unaware of ... Piazza G, Creager MA (April 2010). "Thromboangiitis obliterans". Circulation. 121 (16): 1858-61. doi:10.1161/CIRCULATIONAHA. ...
Schaper WK, Xhonneux R, Jageneau AH (November 1965). "Stimulation of the coronary collateral circulation by lidoflazine (R 7904 ...
There is no collateral circulation present besides the end arteries. Examples of an end artery include the splenic artery that ... The results are severe because the blood flow to that region is completely stopped since there is no collateral circulation. ...
... Cerebral circulation Leptomeningeal collateral circulation Fenrich, Matija; Habjanovic, Karlo ... for collateral circulation in the cerebral circulation. If one part of the circle becomes blocked or narrowed (stenosed) or one ... "Transcranial Doppler ultrasonography of carotid-basilar collateral circulation in subclavian steal". Stroke. 19 (8): 1036-1042 ... The circle of Willis is a part of the cerebral circulation and is composed of the following arteries: Anterior cerebral artery ...
"Transcranial Doppler ultrasonography of carotid-basilar collateral circulation in subclavian steal". Stroke. 19 (8): 1036-42. ... Classically, SSS is a consequence of a redundancy in the circulation of the brain and the flow of blood. SSS results when the ... Lord R, Adar R, Stein R (1969). "Contribution of the circle of Willis to the subclavian steal syndrome". Circulation. 40 (6): ... This is because of collateral vessels.[citation needed] As in vertebral-subclavian steal, coronary-subclavian steal may occur ...
The anastomosis provides collateral circulation in the event of damage to the region. Inferior or distal to the origin of the ...
Schaper W, The collateral circulation of the heart, New York, N.Y.: Elsevier, 1971. Kolibash AJ, et al., "Coronary collateral ... Cohen M and KP Rentrop, et al., "Limitation of myocardial ischemia by collateral circulation during sudden controlled coronary ... Fujita M, "Importance of angina for development of collateral circulation," British Heart Journal 1987; 57: 139-43. (Articles ... collateral circulation, and, in any case, sometimes precedes, and often prevents, infarction by relieving the critically ...
The patients having a significant collateral circulation can live to adulthood in rare cases; their circulation is often not ... Because the pressure in RCA exceeds the pressure in LCA a collateral circulation will increase. This situation ultimately can ... The development of symptoms in ALCAPA depends heavily on the amount of collaterals development. When only few collaterals are ... By the time of birth, the pressure will decrease in the pulmonic artery and the child will have a postnatal circulation. The ...
... the fine collateral circulation that it supplies is obliterated. Patients often survive on the collateral circulation from the ... A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are ... This is also the case when the arterial constriction and collateral circulation are bilateral. Moyamoya syndrome is unilateral ... The arteries are either sewn directly into the brain circulation, or placed on the surface of the brain to reestablish new ...
... providing a collateral circulation. This collateral circulation allows for blood to continue circulating if the subclavian is ...
He pioneered the field of vascular surgery and noted collateral circulation following ligation of arteries. Porta was born in ...
They provide a means of collateral circulation between the femoral vein, and lnternal iliac vein. Standring, Susan (2020). ...
Pulsatile back-bleeding from distal innominate artery stump should be checked to insure collateral circulation. In patients ... Innominate artery ligation leaves the carotid and subclavian circulations intact. ... and the carotid artery or the opposite carotid artery and the subclavian artery may be performed to restore normal circulation ...
This means that collateral circulation develops in the lower esophagus, abdominal wall, stomach, and rectum. The small blood ...
"Pre-stroke Physical Activity and Cerebral Collateral Circulation in Ischemic Stroke: A Potential Therapeutic Relationship?". ... thanks to the increase in peripheral circulation. This also makes changes to tumor vasculature from the increase of cardio and ...
The genicular anastomosis provides collateral circulation to supply the leg when the knee is fully flexed. When the knee ...
Symptoms from poor blood circulation in the arm is uncommon due to collateral circulation in the arm. Young adults without risk ...
... portocaval collateral circulation). collateral circulation (Articles with short description, Short description ... Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor ... It is occasionally also known as accessory circulation, auxiliary circulation, or secondary circulation. It has surgically ... Collateral circulation is created (within months) around the blocked central vein via a generally winding path, usually from a ...
Time From Stroke Onset and Fluid-Attenuated Inversion Recovery Lesion Intensity Is Modified by Status of Collateral Circulation ... Stroke: a journal of cerebral circulation. volume. 47. pages. 1022 pages. publisher. American Heart Association. external ... We hypothesized that collateral status as assessed by the hypoperfusion intensity ratio could modify the association between ... We hypothesized that collateral status as assessed by the hypoperfusion intensity ratio could modify the association between ...
Good collateral circulation has shown protective effects towards a favourable functional outcome and a lower risk of recurrence ... Over the past decade, the importance of collateral circulation has attracted more attention and is becoming a hot spot for ... However, the diversity in imaging methods and criteria to evaluate collateral circulation has hindered comparisons of findings ... and further studies in exploring the clinical relevance of collateral circulation and possible methods to enhance collateral ...
Decreased focal venous circulation around a thrombosed venous sinus * Visualization of collateral circulation ... Dilated venous collaterals, such as transcortical medullary veins, provide indirect evidence of venous thrombosis. The ... including posterior circulation structures as well as cortical areas close to the vertex. In a retrospective review of 10 ... were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial ...
With portal hypertension and the formation of collateral circulations, Cruveilhier-Baumgarten syndrome may develop. This may ...
... collateral circulations are less at risk of developing ischemic stroke than those with ineffective collateral circulations [23, ... Low prevalence of collateral cerebral circulation in the circle of Willis in patients with severe carotid artery stenosis and ... Angiographically defined collateral circulation and risk of stroke in patients with severe carotid artery stenosis. Stroke. ... Riggs HE, Rupp C. Variation in form of circle of Willis: the relation of the variations to collateral circulation: anatomic ...
Collateral Circulation in Thrombectomy for Stroke After 6 to 24 Hours in the DAWN Trial. Liebeskind DS, Saber H, Xiang B, ... Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual ...
Newer anatomy of the liver and its variant blood supply and collateral circulation. Am J Surg. 1966;112:337-347. [PubMed] [DOI] ... Investigations of collateral circulation during temporary balloon occlusion of either of the hepatic arteries have first of all ... Arterial collaterals in the liver hilus. Radiology. 1970;94:575-579. [PubMed] [DOI] [Cited in This Article: ] ... The development of collateral blood flow with one of the hepatic arteries being occluded was shown to be a possibility and to ...
This concept is reversed in fetal circulation AND in cardiac collateral circulation; therefore, a tip is to think of blood not ...
Also improves coronary collateral circulation. Lower BP, increased HR, occasional paradoxical bradycardia ...
It is not fully understood which factors are involved in the development of postoperative collateral circulation. In this study ...
... vasculogenic mimicry and arteriogenesis are the seven main ways of collateral vessel development. However, none of the ... ... W. Schaper, Collateral circulation: past and present, Basic. Res. Cardiol. 104 (2009) 5-21. ... are the precursors of collateral vessels. The development of VSMC solid cell cords into collateral vessels can be divided into ... N. Hakimzadeh, H.J. Verberne, M. Siebes, J.J. Piek, The future of collateral artery research, Curr. Cardiol. Rev. 10 (2014) 73- ...
Maxillary involvement is rare due to the collateral blood circulation it receives. Of these six trials, two were cross-over ... subluxation these are associated with extreme Muscles and tendons traumatic damage to the joint capsule and collateral Muscle ...
Pathways and functional significance of the coronary collateral circulation. Circulation. 1975;50 (4): 831-7. Pubmed citation ... another more important role it serves in pathophysiology is that of a route of collateral circulation. The conus artery has ... Vieussens arterial ring is an anastomotic conduit between the conus artery and the left coronary circulation 6. ... The conus artery is a small early branch off the right coronary artery (RCA) circulation. ...
There were no stigmata of chronic liver disease like clubbing, gynecomastia, collateral circulation, ascites, sarcopenia, ...
Collateral circulation occurs with some frequency and may be a factor affecting the detectability of myocardial perfusion ... A = area under curve for first pulmonary circulation; B = area corresponding to early pulmonary recirculation (A/A − B = Qp:Qs ... For example, newborns and infants have a lower glomerular filtration rate, faster circulation, and faster pulmonary wash-in and ...
collateral circulation. *reduced *blood pressure. *platelet aggregation. *plasminogen activator inhibitor 1. *plasma-fibrinogen ...
Symptoms may spontaneously resolve due to the establishment of extracranial collaterals to the subclavian circulation. This ... Symptoms are usually related to vertebrobasilar and posterior cerebral circulation ischaemia.. On exercising the upper limb on ...
At one year follow-up, there was the evidence of occlusion of collateral circulation on the right side and the patient became ...
... is when the capillary network or collateral circulation cannot be reestablished following a traumatic injury or when the ...
Collateral circulation. As the blockage in a coronary artery gets bigger and if it occurs slowly, new blood vessels may form to ... This is called collateral circulation. These new blood vessels may not be able to carry enough blood to the heart when there is ... The bypasses are called collaterals and are made up of small branches of blood vessels. Enhanced external counterpulsation is a ...
Collateral Circulation. *Mukufamba kwenguva pfupi kufambira mberi kwakadai seatrosclerotic thrombosis, kushambadzirwa ...
Schaper W, Buschmann I. Collateral circulation and diabetes. Circulation. 1999; 99: 2224-2226.. 14. Henry TD, Annex BH, ... significance for the development of the coronary artery collateral circulation. Circulation 1999; 100: 547-552. ... excellent collateral flow) and grade 2 (good collateral flow), respectively. Patients with poor collateral flow were put into ... As the severity of stenosis has an effect on the collateral growth, the presence and quick development of collaterals will ...
Among the collateral midzones, baseline elastic fiber content is low. Outward remodeling of these vessels with a 10-20 fold ... Collateral artery development is associated with permanent redistribution of existing elastic fibers to accommodate diameter ... Collateral arteries harvested at different timepoints showed progressive diameter expansion associated with striking ... Despite a 2.5-fold increase in luminal diameter, total elastin content remained unchanged in collaterals compared with control ...
Impact of Collateral Circulation on Futile Endovascular Thrombectomy in Acute Anterior Circulation Ischemic Stroke Yoo Sung ...
Inter-rater reliability for assessing intracranial collaterals in patients with acute ischemic stroke: comparing 29 raters and ... Collateral Circulation Neuroscience 33% View full fingerprint Collaborations and top research areas from the last five years ...
... use by interventional cardiologists as a one-time treatment to promote and stimulate the growth of collateral circulation in ...
Persistent trigeminal artery as collateral circulation in ischemic stroke. World Neurosurg. 2021; 148: 67-69.. CrossRefPubMed ... Persistent trigeminal artery in a patient with posterior circulation stroke treated with rt-PA: case report. BMC Neurol. 2019; ...
  • Consequences of newly established venous collaterals arising from portal hypertension include esophageal varices and hemorrhoids (portocaval collateral circulation). (
  • There were signs of local compression with dysphonia, respiratory distress, and superior vena cava syndrome with collateral venous circulation (Figure 1, Figure 2). (
  • The skin was fistulized and showed local signs of compression with superior vena cava syndrome with collateral venous circulation. (
  • Collateral Circulation in Thrombectomy for Stroke After 6 to 24 Hours in the DAWN Trial. (
  • 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40?7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06?0.47) were risk factors for postoperative ischemic complications. (
  • Symptoms are usually related to vertebrobasilar and posterior cerebral circulation ischaemia. (
  • The PCoA extends posteriorly to connect with the primary segment of the posterior cerebral artery (PCA), allowing collateral flow to pass between the anterior and posterior circulations. (
  • However, none of the seven methods of collateral vessel development is sufficient to timely rescue a large number of dying myocardial cells in the myocardial infarction area. (
  • Tissue flow in the collateral dependent myocardial region did not change in response to atrial natriuretic peptide. (
  • Blood flow to the brain in humans and some other animals is maintained via a network of collateral arteries that anastomose (join) in the circle of Willis, which lies at the base of the brain. (
  • The circulatory system of the human hand features extensive collateral circulation in the form of the deep and superficial palmar arches, and the proper palmar digital arteries of the digits, with the exception of the thumb, which has its blood supplied by the princeps pollicis artery. (
  • Collateral circulation in the heart tissue will sometimes bypass the blockage in the main artery and supply enough oxygenated blood to enable the cardiac tissue to survive and recover. (
  • Injection of radioactive microspheres during retrograde flow collection allowed simultaneous determination of continuing tissue flow for evaluation of microvascular collateral communications. (
  • The conus artery is a small early branch off the right coronary artery (RCA) circulation. (
  • Studies were performed in nine adult mongrel dogs 3.4 months after embolic occlusion of the left anterior descending coronary artery had been performed to stimulate collateral vessel growth. (
  • At the time of study the anterior descending coronary artery was cannulated to allow estimation of interarterial collateral flow from measurements of retrograde blood flow. (
  • We studied the interaction between collateral status on the association between time from symptom onset and FLAIR intensity. (
  • Our findings show that the relationship between time from symptom onset and rFLAIR lesion intensity depends on collateral status. (
  • In patients with good collaterals, the development of an rFLAIR-positive lesion is less dependent on time from symptom onset compared with patients with poor collaterals. (
  • In this study, we first proposed the hypothesis that vascular smooth muscle cell (VSMC) solid cell cords are precursors of collateral vessels and confirmed the existence of VSMC solid cell cords in the heart. (
  • is when the capillary network or collateral circulation cannot be reestablished following a traumatic injury or when the vascular system is disrupted by other means. (
  • After the larger dose of atrial natriuretic peptide, the administration of nitroglycerin (10 μg/kg into the left atrium) caused no further increase of retrograde blood flow, and no further decrease of collateral vascular resistance. (
  • Orthodontic forces may impede pulp circulation, causing vascular congestion and pulp edema, leading to pulp damage 14,27 and even necrosis in teeth submitted to traction [29]. (
  • Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels. (
  • The conus artery has been shown to collateralise with the more distal acute marginal branch in RCA stenosis/obstruction, and collateralise with the left anterior descending artery (LAD) in LAD stenosis/obstruction, providing a potentially vital collateral pathway. (
  • The 2 ACAs connect through the anterior communicating artery (ACoA), thus joining the left and right carotid circulations. (
  • Although an acute occlusion of the tiny artery has been shown to result in S-T elevation, another more important role it serves in pathophysiology is that of a route of collateral circulation. (
  • Even though the main vessels to the leg are blocked, enough blood can get to the tissues in the leg via the collateral circulation to keep them alive. (
  • A slow and progressive circulation disorder that causes narrowed blood vessels, reducing blood flow in the arms or legs. (
  • This study was carried out to examine the effects of atrial natriuretic peptide on coronary collateral blood flow. (
  • Evening primrose also has the effects of promoting blood circulation and collaterals, reducing swelling and relieving pain. (
  • Clinical tory illness as well as real changes in influenza virus circulation laboratories primarily test respiratory specimens for diagnos- because of widespread implementation of measures to mitigate tic purposes, and data from these laboratories provide useful transmission of SARS-CoV-2. (
  • Association Between Time From Stroke Onset and Fluid-Attenuated Inversion Recovery Lesion Intensity Is Modified by Status of Collateral Circulation. (
  • We hypothesized that collateral status as assessed by the hypoperfusion intensity ratio could modify the association between time from stroke onset and FLAIR lesion intensity. (
  • A hypoperfusion intensity ratio threshold of ≤0.4 was used to dichotomize good versus poor collaterals. (
  • The specific weight of Bupicain® 2.5 mg/mL and 5 mg/mL with or without a vasoconstrictor is 1.006 at 20°C and 0.997 at 37°C. If infiltrations are administered for local anaesthesia in areas that lack the possibility of collateral circulation (fingers, root of penis, etc.), it is a good precaution to use the anaesthetic without a vasoconstrictor to avoid ischaemic necrosis. (
  • Vasculogenesis, sprouting angiogenesis, intussusceptive angiogenesis, coalescent angiogenesis, vessel co-option, vasculogenic mimicry and arteriogenesis are the seven main ways of collateral vessel development. (
  • Vieussens' arterial ring is an anastomotic conduit between the conus artery and the left coronary circulation 6 . (
  • Circulation research , 65 (6), 1671-1678. (
  • Previous studies have shown that vascular endothelial growth factor , endothelial progenitor cells , Caveolin-1 , and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. (
  • Thrombi are of clinical importance due to occlusion of vessels and loss of blood supply leading to infarction, particularly in organs that lack collateral circulation. (
  • The importance of coronary collaterals is underscored by the demonstration that the degree of myocardial dysfunction that develops in patients following acute occlusion of a coronary artery (during balloon angioplasty, for example) is inversely related to the extent of collateral vessels present (1). (
  • Collateral circulations are often smaller vessels that are close to the blocked vessel. (
  • Moreover, the proposed method provides new insight regarding the heterogeneous configuration of the alternative collateral vessels. (
  • Peripheral artery disease is a form of arterial insufficiency, means blood flowing(circulation) through the arteries (i.e. blood vessels that carry blood away from the heart) is decreased. (
  • Type 2 is the condition of little intracranial circulation with contrast filling just only at vessels of brain base, type 3 is of no or little cortical circulation with contrast filling at bilateral large vessels of brain base through circle of Willis channel and type 4 is of visible bilateral cortical circulation but delayed intracranial circulation time. (
  • Surgery conducted on the patient by a team of doctors, who occluded the blood vessels using coils and embellished the collateral vessels. (
  • Conclusions Collateral circulation between the anterior tibial artery and posterior tibial artery is active and there is almost always occlusion in the posterior tibial artery branches. (
  • The posterior tibial artery angiosome is fed by the collateral arteries of the anterior tibial artery even if there is no occlusion of posterior tibial artery at the level of the leg, so indirect revascularization on the anterior tibial artery is sufficient to provide foot circulation. (
  • In this study, we investigated the association between -786T/C polymorphism of the endothelial nitric oxide (NOS3) gene in which thymidine is replaced by a cytosine at nucleotide -786 (rs 2070744) and coronary collateral circulation (CCC) in patients with stable coronary artery disease. (
  • Well-developed collaterals may greatly limit or even completely eliminate myocardial infarction despite complete occlusion of a coronary artery. (
  • Collateral blood flow from the ulnar artery usually prevents significant ischemia. (
  • The PLAU P141L single nucleotide polymorphism is associated with collateral circulation in patients with coronary artery disease. (
  • Richard Lower provided the first description of coronary collaterals in humans in 1669, when he noted that fluid injected into one coronary artery emerged from another. (
  • The presence of functional collaterals enables the heart to maintain essentially normal perfusion under resting conditions, despite near-total occlusion of a major coronary artery. (
  • Moreover, myocardial viability in patients with recent myocardial infarction (MI) is correlated with the extent of collateral blood flow within the territory of the infarct-related artery (2). (
  • The term "collateral circulation" means the alternate circulation "pathway" the blood can take around a blocked artery or vein. (
  • The myocardium has some collateral circulation that the blood can use when an artery is blocked. (
  • Computational models can help understand the hemodynamics of the coronary circulation, which is of the upmost importance to help clinicians before, during and after a coronary artery bypass graft surgery. (
  • From there it flows into the right ventricle and out through the pulmonary artery into pulmonary circulation. (
  • Peripheral Artery Disease or Peripheral vascular disease (PVD) is a slow-growing circulation disorder. (
  • It is the most accurate test to detect the location(s) and severity of artery obstructions, as well as collateral circulations. (
  • There is evidence that regular exercise reduces the risk of sudden death in patients suffering from coronary insufficiency by increasing the diameter of coronary arteries and collateral circulation, and reduces sensitivity to coronary artery spasm. (
  • The coronary collateral circulation is an important factor in terms of the amount of damage to the myocardium that results from coronary occlusion. (
  • The patients who benefit from emergent catheterization are those with acute coronary occlusion (ACO) or near occlusion, with insufficient collateral circulation, whose myocardium is at imminent risk of irreversible infarction without immediate reperfusion therapy. (
  • The donor lung is prepared at the back table, taking care to preserve peribronchial collateral circulation to the donor lungs. (
  • From here it is pumped into the pulmonary circulation, through the lungs where it receives oxygen and gives off carbon dioxide. (
  • In the context of Qing Luo Yin, it is used because it clears and vents the collaterals of the Lungs . (
  • many patients develop collaterals in the hours and days after an occlusion occurs. (
  • In general Si Gua Luo's main actions are as follows: 'Removes obstructions in the Collaterals, promotes blood circulation and cools Blood, clears heat and detoxifies. (
  • [ 46 ] When the patient is at rest, blood flow through collaterals is normal, a fact that accounts for the absence of resting ischemia. (
  • If the affected organ or tissue does not have adequate collateral circulation, tissue ischemia and tissue necrosis can result. (
  • The brain and the heart are the two organs most likely to be detrimentally affected by microbubbles in circulation, though any organ or tissue can suffer ischemia. (
  • A venous air embolism occurs when air enters venous circulation and moves to the right ventricle of the heart and then into pulmonary circulation where it becomes lodged. (
  • Because it enters pulmonary circulation, you may see this referred to as a pulmonary air embolism. (
  • However, larger air embolisms can obstruct pulmonary circulation leading to obstructive shock and cardiovascular collapse. (
  • By reducing the myocardial load and improving the coronary circulation do organic nitrates treat anginal pain efficiently. (
  • Among Hunt&Hess grade IV, V SAH patients, the author could gather eight patients who showed abnormal intracranial circulation in cerebral catheter-based angiography. (
  • An arterial air embolism enters arterial circulation and travels to organs and tissues throughout the body. (
  • Air emboli can occur through direct introduction of air into the arterial side of circulation such as in surgery or trauma. (
  • The heart receives blood low in oxygen from the systemic circulation, which enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle. (
  • Oxygenated blood then returns to the left atrium, passes through the left ventricle and is pumped out through the aorta to the systemic circulation−where the oxygen is used and metabolized to carbon dioxide. (
  • It enters at the left atrium, flows into the left ventricle and is pumped out through the aorta into systemic circulation. (
  • Coronary arteriography showed three-vessel atherosclerotic disease with development of some collateral circulation. (
  • When a blood vessel is blocked in any limb of the body a parallel circulation is to be expected and a healthy condition follows. (
  • Multiobjective patient-specific estimation of a coronary circulation model for triple vessel disease. (
  • In this paper, we propose a multiobjective optimization method for parameter estimation of a computational model representing the coronary circulation on patients with a triple vessel disease. (
  • Collateral circulation between angiosomes in the feet of diabetic patients. (
  • Approximately 1 in every 300 patients with chest pain transported to the ED by private vehicle goes into cardiac arrest en route. (
  • 8. Clinical impact of collateral circulation in patients with median arcuate ligament syndrome. (
  • Chez les patients hypertendus, le taux de mortalité était plus élevé uniquement chez les patients admis pour un infarctus du myocarde avec sus-décalage du segment ST. Après ajustement des résultats en fonction des variables de référence, l'hypertension s'est révélé être un facteur prédictif indépendant de l'insuffisance cardiaque (OR = 1,31) et de l'accident vasculaire cérébral (OR = 2,47). (
  • The prognosis of these eight patients showed misery collaterals were disappointed. (
  • Given the clinical importance of collaterals, two important questions emerge: what factors lead to their development, and what is the possibility that their growth can be enhanced pharmacologically? (
  • The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke , and is the main method for evaluating the effect of indirect revascularization. (
  • Introduction of foreign material into circulation may give rise to emboli, ultimately leading to thrombosis. (
  • In early 1985, we embarked on a series of experiments in which we hoped to facilitate the development of coronary collaterals by using angiogenic substances. (
  • If the collateral circulation is extensive enough the patient may not have any symptoms. (
  • Indeed, the collateral development of a given patient is estimated through the model parameters. (
  • This pressure gradient makes it easier for air to enter circulation, especially if the patient is in a more upright position. (
  • The author introduces new term 'misery collaterals' first and has classified them into four types with the case illustrations. (
  • 3 Moreover, the MAIKONG high potential therapy harga device can promote the blood circulation, activate collaterals, relieve pain, etc. (
  • Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease . (
  • With the increase in flow, augmented collateral shear stress and tangential wall stress (stretch) may be important triggers in the initiation of angiogenesis (7). (
  • Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review. (
  • This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease . (
  • Ayurvedic medicines can augment the formation of this parallel circulation. (
  • Subsequently, Schaper and co-workers provided support for the concept of a diffusible mediator of collateral growth in the heart (6). (
  • Large bubbles of air usually block the pulmonary outflow tract which decreases the circulation of blood from the right side of the heart. (
  • Type 1 is the worst condition defined as almost no intracranial circulation. (