Venae Cavae: The inferior and superior venae cavae.Vena Cava, Superior: The venous trunk which returns blood from the head, neck, upper extremities and chest.Vena Cava, Inferior: The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs.Vena Cava Filters: Mechanical devices inserted in the inferior vena cava that prevent the migration of blood clots from deep venous thrombosis of the leg.Superior Vena Cava Syndrome: A condition that occurs when the obstruction of the thin-walled SUPERIOR VENA CAVA interrupts blood flow from the head, upper extremities, and thorax to the RIGHT ATRIUM. Obstruction can be caused by NEOPLASMS; THROMBOSIS; ANEURYSM; or external compression. The syndrome is characterized by swelling and/or CYANOSIS of the face, neck, and upper arms.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)EncyclopediasDictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Crisscross Heart: A developmental malformation of the heart characterized by a twisted but not defective atrioventicular connection. The abnormal rotation of the ventricular mass around its long axis results in the crossing of the inflow streams of the two ventricles. Other features include hypoplasia of the TRICUSPID VALVE and RIGHT VENTRICLE.Veins: The vessels carrying blood away from the capillary beds.Foramen Ovale: An opening in the wall between the right and the left upper chambers (HEART ATRIA) of a fetal heart. Oval foramen normally closes soon after birth; when it fails to close the condition is called PATENT OVAL FORAMEN.Brachiocephalic Veins: Large veins on either side of the root of the neck formed by the junction of the internal jugular and subclavian veins. They drain blood from the head, neck, and upper extremities, and unite to form the superior vena cava.Pancreatin: A mammalian pancreatic extract composed of enzymes with protease, amylase and lipase activities. It is used as a digestant in pancreatic malfunction.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Pulmonary Veins: The veins that return the oxygenated blood from the lungs to the left atrium of the heart.Heart: The hollow, muscular organ that maintains the circulation of the blood.Azygos Vein: A vein which arises from the right ascending lumbar vein or the vena cava, enters the thorax through the aortic orifice in the diaphragm, and terminates in the superior vena cava.Blood Transfusion, Autologous: Reinfusion of blood or blood products derived from the patient's own circulation. (Dorland, 27th ed)Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Materials Management, Hospital: The management of all procurement, distribution, and storage of equipment and supplies, as well as logistics management including laundry, processing of reusables, etc.Blood Loss, Surgical: Loss of blood during a surgical procedure.Hemodilution: Reduction of blood viscosity usually by the addition of cell free solutions. Used clinically (1) in states of impaired microcirculation, (2) for replacement of intraoperative blood loss without homologous blood transfusion, and (3) in cardiopulmonary bypass and hypothermia.Appendix: A worm-like blind tube extension from the CECUM.Dyscalculia: Impaired ability in numerical concepts. These inabilities arise as a result of primary neurological lesion, are syndromic (e.g., GERSTMANN SYNDROME ) or acquired due to brain damage.Faculty: The teaching staff and members of the administrative staff having academic rank in an educational institution.Education, Graduate: Studies beyond the bachelor's degree at an institution having graduate programs for the purpose of preparing for entrance into a specific field, and obtaining a higher degree.Faculty, Medical: The teaching staff and members of the administrative staff having academic rank in a medical school.Faculty, Dental: The teaching staff and members of the administrative staff having academic rank in a dental school.Faculty, Nursing: The teaching staff and members of the administrative staff having academic rank in a nursing school.Students: Individuals enrolled in a school or formal educational program.History of MedicineEquipment Safety: Freedom of equipment from actual or potential hazards.Device Approval: Process that is gone through in order for a device to receive approval by a government regulatory agency. This includes any required preclinical or clinical testing, review, submission, and evaluation of the applications and test results, and post-marketing surveillance. It is not restricted to FDA.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Equipment and Supplies: Expendable and nonexpendable equipment, supplies, apparatus, and instruments that are used in diagnostic, surgical, therapeutic, scientific, and experimental procedures.Diagnostic Equipment: Nonexpendable items used in examination.Natural Orifice Endoscopic Surgery: Surgical procedures performed through a natural opening in the body such as the mouth, nose, urethra, or anus, and along the natural body cavities with which they are continuous.Hyperthermia, Induced: Abnormally high temperature intentionally induced in living things regionally or whole body. It is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.Steam Bath: Therapy of sitting in a hot steamy room followed by a cool bath or shower.Laser Therapy: The use of photothermal effects of LASERS to coagulate, incise, vaporize, resect, dissect, or resurface tissue.Endoscopes: Instruments for the visual examination of interior structures of the body. There are rigid endoscopes and flexible fiberoptic endoscopes for various types of viewing in ENDOSCOPY.Elasticity Imaging Techniques: Non-invasive imaging methods based on the mechanical response of an object to a vibrational or impulsive force. It is used for determining the viscoelastic properties of tissue, and thereby differentiating soft from hard inclusions in tissue such as microcalcifications, and some cancer lesions. Most techniques use ultrasound to create the images - eliciting the response with an ultrasonic radiation force and/or recording displacements of the tissue by Doppler ultrasonography.Adnexa Uteri: Appendages of the UTERUS which include the FALLOPIAN TUBES, the OVARY, and the supporting ligaments of the uterus (BROAD LIGAMENT; ROUND LIGAMENT).Radiology, Interventional: Subspecialty of radiology that combines organ system radiography, catheter techniques and sectional imaging.Cancer Care Facilities: Institutions specializing in the care of cancer patients.Medical Oncology: A subspecialty of internal medicine concerned with the study of neoplasms.Radiography, Interventional: Diagnostic and therapeutic procedures that are invasive or surgical in nature, and require the expertise of a specially trained radiologist. In general, they are more invasive than diagnostic imaging but less invasive than major surgery. They often involve catheterization, fluoroscopy, or computed tomography. Some examples include percutaneous transhepatic cholangiography, percutaneous transthoracic biopsy, balloon angioplasty, and arterial embolization.Radiology: A specialty concerned with the use of x-ray and other forms of radiant energy in the diagnosis and treatment of disease.National Cancer Institute (U.S.): Component of the NATIONAL INSTITUTES OF HEALTH. Through basic and clinical biomedical research and training, it conducts and supports research with the objective of cancer prevention, early stage identification and elimination. This Institute was established in 1937.Program Evaluation: Studies designed to assess the efficacy of programs. They may include the evaluation of cost-effectiveness, the extent to which objectives are met, or impact.

The cyclo-oxygenase-dependent regulation of rabbit vein contraction: evidence for a prostaglandin E2-mediated relaxation. (1/230)

1. Arachidonic acid (0.01-1 microM) induced relaxation of precontracted rings of rabbit saphenous vein, which was counteracted by contraction at concentrations higher than 1 microM. Concentrations higher than 1 microM were required to induce dose-dependent contraction of vena cava and thoracic aorta from the same animals. 2. Pretreatment with a TP receptor antagonist (GR32191B or SQ29548, 3 microM) potentiated the relaxant effect in the saphenous vein, revealed a vasorelaxant component in the vena cava response and did not affect the response of the aorta. 3. Removal of the endothelium from the venous rings, caused a 10 fold rightward shift in the concentration-relaxation curves to arachidonic acid. Whether or not the endothelium was present, the arachidonic acid-induced relaxations were prevented by indomethacin (10 microM) pretreatment. 4. In the saphenous vein, PGE2 was respectively a 50 and 100 fold more potent relaxant prostaglandin than PGI2 and PGD2. Pretreatment with the EP4 receptor antagonist, AH23848B, shifted the concentration-relaxation curves of this tissue to arachidonic acid in a dose-dependent manner. 5. In the presence of 1 microM arachidonic acid, venous rings produced 8-10 fold more PGE2 than did aorta whereas 6keto-PGF1alpha and TXB2 productions remained comparable. 6. Intact rings of saphenous vein relaxed in response to A23187. Pretreatment with L-NAME (100 microM) or indomethacin (10 microM) reduced this response by 50% whereas concomitant pretreatment totally suppressed it. After endothelium removal, the remaining relaxing response to A23187 was prevented by indomethacin but not affected by L-NAME. 7. We conclude that stimulation of the cyclo-oxygenase pathway by arachidonic acid induced endothelium-dependent, PGE2/EP4 mediated relaxation of the rabbit saphenous vein. This process might participate in the A23187-induced relaxation of the saphenous vein and account for a relaxing component in the response of the vena cava to arachidonic acid. It was not observed in thoracic aorta because of the lack of a vasodilatory receptor and/or the poorer ability of this tissue than veins to produce PGE2.  (+info)

Pulmonary and caval flow dynamics after total cavopulmonary connection. (2/230)

OBJECTIVE: To assess flow dynamics after total cavopulmonary connection (TCPC). DESIGN: Cross-sectional study. SETTING: Aarhus University Hospital. PATIENTS: Seven patients (mean age 9 (4-18) years) who had previously undergone a lateral tunnel TCPC mean 2 (0. 3-5) years earlier. INTERVENTIONS: Pressure recordings (cardiac catheterisation), flow volume, and temporal changes of flow in the lateral tunnel, superior vena cava, and right and left pulmonary arteries (magnetic resonance velocity mapping). RESULTS: Superior vena cava flow was similar to lateral tunnel flow (1.7 (0.6-1.9) v 1. 3 (0.9-2.4) l/min*m2) (NS), and right pulmonary artery flow was higher than left pulmonary artery flow (1.7 (0.6-4.3) v 1.1 (0.8-2. 5) l/min*m2, p < 0.05). The flow pulsatility index was highest in the lateral tunnel (2.0 (1.1-8.5)), lowest in the superior vena cava (0.8 (0.5-2.4)), and intermediate in the left and right pulmonary arteries (1.6 (0.9-2.0) and 1.2 (0.4-1.9), respectively). Flow and pressure waveforms were biphasic with maxima in atrial systole and late ventricular systole. CONCLUSIONS: Following a standard lateral tunnel TCPC, flow returning via the superior vena cava is not lower than flow returning via the inferior vena cava as otherwise seen in healthy subjects; flow distribution to the pulmonary arteries is optimal; and some pulsatility is preserved primarily in the lateral tunnel and the corresponding pulmonary artery. This study provides in vivo data for future in vitro and computer model studies.  (+info)

Rate-dependent conduction block of the crista terminalis in patients with typical atrial flutter: influence on evaluation of cavotricuspid isthmus conduction block. (3/230)

BACKGROUND: The crista terminalis (CT) has been identified as the posterior boundary of typical atrial flutter (AFL) in the lateral wall (LW) of the right atrium (RA). To study conduction properties across the CT, rapid pacing was performed at both sides of the CT after bidirectional conduction block was achieved in the cavotricuspid isthmus by radiofrequency catheter ablation. METHODS AND RESULTS: In 22 patients (aged 61+/-7 years) with AFL (cycle length, 234+/-23 ms), CT was identified during AFL by double electrograms recorded between the LW and posterior wall (PW). After the ablation procedure, decremental pacing trains were delivered from 600 ms to 2-to-1 local capture at the LW and PW or coronary sinus ostium (CSO). At least 5 bipolar electrograms were recorded along the CT from the high to the low atrium next to the inferior vena cava. No double electrograms were recorded during sinus rhythm in that area. Complete transversal conduction block all along the CT (detected by the appearance of double electrograms at all recording sites and craniocaudal activation sequence on the side opposite to the pacing site) was observed in all patients during pacing from the PW or CSO (cycle length, 334+/-136 ms), but it was fixed in only 4 patients. During pacing from the LW, complete block appeared at a shorter pacing cycle length (281+/-125 ms; P<0.01) and was fixed in 2 patients. In 3 patients, complete block was not achieved. CONCLUSIONS: These data suggest the presence of rate-dependent transversal conduction block at the crista terminalis in patients with typical AFL. Block is usually observed at longer pacing cycle lengths with PW pacing than with LW pacing. This difference may be a critical determinant of the counterclockwise rotation of typical AFL.  (+info)

Hepatic vascular exclusion with preservation of the caval flow for liver resections. (4/230)

OBJECTIVE: To report the technique and results of an alternative method of vascular clamping during liver resections. BACKGROUND: Most liver resections require vascular clamping to avoid excessive blood loss. Portal triad clamping is often sufficient, but it does not suppress backflow bleeding, which can be prevented only by hepatic vascular exclusion. The latter method adds clamping of the inferior vena cava, which results in hypotension, requiring invasive anesthetic management. There is growing evidence that intermittent clamping is better tolerated than continuous clamping, especially in the presence of underlying liver disease. METHODS: Hepatic vascular exclusion with preservation of the caval flow (HVEPC) involved conventional inflow clamping associated with outflow control by clamping the major hepatic veins, thus avoiding caval occlusion. HVEPC was used in 40 patients undergoing major or complex liver resection, including 16 with underlying liver disease. HVEPC was total (clamping of the porta hepatis and all major hepatic veins) in 20 cases and partial (clamping of the porta hepatis and the hepatic veins of the resected territory) in 20. Clamping was continuous in 22 cases and intermittent in 18. Resections included 12 hemihepatectomies, 12 extended hepatectomies, 3 central hepatectomies, and 13 uni- or bisegmentectomies. RESULTS: Hemodynamic tolerance of clamping was excellent in all cases, without the need for therapeutic adjustment. Median red cell transfusion requirements were 0 units, and 28 patients (70%) did not receive any transfusions during the hospital stay. There were no deaths, and the morbidity rate was 17.5%. Median hospital stay was 10 days. CONCLUSION: HVEPC is a safe and effective procedure applicable to liver tumors without invasion to the inferior vena cava. It offers the advantages of conventional hepatic vascular exclusion without its hemodynamic drawbacks, and it can be applied intermittently or partially.  (+info)

Cardiac consequences of prolonged exposure to an isolated increase in aortic stiffness. (5/230)

In elderly patients, aortic stiffness is a major determinant of increased end-systolic stress leading to left ventricular (LV) hypertrophy with impaired cardiac performance. However, in a rat model of aortic elastocalcinosis (induced by vitamin D(3)-nicotine [VDN] treatment), brief exposure (1 month) to increased aortic stiffness modified neither cardiac function nor cardiac structure. Here we report the impact of longer exposure (3 months) to aortic stiffness. Three months after induction of aortic stiffness, aortic characteristic impedance was measured in awake rats, 8 control and 10 VDN. Stroke volume was measured (electromagnetic probe) at baseline and after acute volume overload. LV weight/body weight ratio, collagen, and myosin heavy chain (MHC) contents were determined. Although aortic characteristic impedance increased (controls, 32+/-2; VDN rats, 50+/-8 10(3) dyne. s/cm(5); P=0.0248), stroke volume was maintained in VDN rats at baseline (controls, 223+/-18; VDN, 211+/-13 microL) and after volume overload (controls, 378+/-14; VDN, 338+/-15 microL). However, LV weight/body weight ratio (controls, 1.54+/-0.07; VDN, 1.73+/-0.05 g/kg; P=0.0397) and LV collagen content (controls, 31+/-4; VDN, 52+/-4 microgram/g dry wt; P=0.0192) increased. A shift from alpha-MHC (controls, 82+/-2%; VDN, 69+/-3%; P=0.0056) to beta-MHC (controls, 18+/-2%; VDN, 31+/-3%; P=0. 0056) was also observed. Three months' exposure to increased aortic stiffness in VDN rats induced LV hypertrophy with moderate interstitial fibrosis and a shift in the MHC-isoform pattern. Such structural adaptation maintains LV performance.  (+info)

Tissue factor activity is increased in human endothelial cells cultured under elevated static pressure. (6/230)

We tested the hypothesis that elevated blood pressure, a known stimulus for vascular remodeling and an independent risk factor for the development of atherosclerotic disease, can modulate basal and cytokine-induced tissue factor (TF; CD 142) expression in cultured human endothelial cells (EC). Using a chromogenic enzymatic assay, we measured basal and tumor necrosis factor-alpha (TNF-alpha; 10 ng/ml, 5 h)-induced TF activities in human aortic EC (HAEC) and vena cava EC (HVCEC) cultured at atmospheric pressure and at 170 mmHg imposed pressure for up to 48 h. Basal TF activities were 22 +/- 10 U/mg protein for HAEC and 14 +/- 9 U/mg protein for HVCEC and were upregulated in both cell types >10-fold by TNF-alpha. Exposure to pressure for 5 h induced additional elevation of basal TF activity by 47 +/- 16% (P < 0.05, n = 6) for HAEC and 17 +/- 5% (P < 0.05, n = 3) for HVCEC. Pressurization also enhanced TF activity in TNF-alpha-treated cells from 240 +/- 28 to 319 +/- 32 U/mg protein in HAEC (P < 0.05, n = 4) and from 148 +/- 25 to 179 +/- 0.8 U/mg protein (P < 0.05, n = 3) in HVCEC. Cytokine stimulation caused an approximately 100-fold increase in steady-state TF mRNA levels in HAEC, whereas pressurization did not alter either TF mRNA or cell surface antigen expression, as determined by quantitative RT-PCR methodology and ELISA. Elevated pressure, however, modulated the EC plasma membrane organization and/or permeability as inferred from the increased cellular uptake of the fluorescent amphipathic dye merocyanine 540 (33 +/- 7%, P < 0.05). Our data suggest that elevated static pressure modulates the hemostatic potential of vascular cells by modifying the molecular organization of the plasma membrane.  (+info)

Inhibition of neointima hyperplasia of mouse vein grafts by locally applied suramin. (7/230)

BACKGROUND: Saphenous vein grafts are widely used for aortocoronary bypass surgery as treatment for severe atherosclerosis and often are complicated by subsequent occlusion of the graft vessel. METHODS AND RESULTS: We described a mouse model of venous bypass graft arteriosclerosis that can be effectively retarded by locally applied suramin, a growth factor receptor antagonist. Mouse isogeneic vessels of the vena cava veins pretreated with suramin were grafted end to end into the carotid arteries and enveloped with a mixture of suramin (1 mmol/L) and pluronic-127 gel. In the untreated group, vessel wall thickening was observed as early as 1 week after surgery and progressed to 4-fold and 10-fold the original thickness in grafted veins at 4 and 8 weeks, respectively. Pluronic-127 gel alone did not influence neointima formation. Suramin treatment reduced the neointima hyperplasia 50% to 70% compared with untreated controls. Immunohistochemical studies demonstrated that a significant proliferation of vascular smooth muscle cells (SMCs) constituted neointimal lesions between 4 and 8 weeks. The majority of SMCs expressed platelet-derived growth factor (PDGF) receptors-alpha and -beta, which were significantly reduced by suramin treatment. In vitro studies indicated that suramin completely blocked PDGF receptor activation or phosphorylation stimulated by PDGF-AB, inhibited activation of mitogen-activated protein kinase (ERK) kinases (MEK1/2) and ERK1/2, and abrogated transcription factor AP-1 DNA-binding activity. CONCLUSIONS: Suramin inhibited SMC migration and proliferation in vivo and in vitro by blocking PDGF-initiated PDGF receptor and MAPK-AP-1 signaling. These findings indicate that locally applied suramin is effective in a mouse model of venous bypass graft arteriosclerosis.  (+info)

Aromatase and sex steroid receptors in human vena cava. (8/230)

Among sex steroids, especially estrogen metabolism has been considered to play a role in the function and pathology of human veins. We investigated the expression and activity of the estrogen-producing enzyme aromatase and estrogen receptor (ER) in human vena cava to assess possible in situ biosynthesis of estrogens and their modes of action. We first examined aromatase expression by immunohistochemistry in human inferior vena cava obtained from 29 autopsy cases (11 males, 18 females, 63.6 +/- 3.0 years old). We then semiquantitated the level of aromatase mRNA by reverse transcriptase-polymerase chain reaction in 24 cases and aromatase activity by 3H-water assay in 15 cases to examine whether or not and in which cell types aromatase was expressed. We also studied alternative use of multiple exon 1s of its gene and immunolocalization of 17beta-hydroxysteroid dehydrogenase type I (17beta-HSD I), which converts estrone produced by aromatase to estradiol, a biologically active estrogen and ER. Aromatase and 17beta-HSD I immunoreactivity were both detected in smooth muscle cells (SMC) of the media in all the cases and in endothelial cells (EC) in 20 and 22 cases, respectively. ER immunoreactivity was detected in SMC of vena cava in 21 cases. The amount of aromatase mRNA was significantly greater in the cases utilizing 1c (I.3) or 1d (P.II) of exon 1 (9 cases, 191.1 +/- 26.3 attomol/ng total RNA) than those utilizing 1b (I.4) as the promoter (14 cases, 50.6 +/- 13.0 attomol/ng total RNA) (p < 0.01). Significant correlation (p < 0.05) was observed between the amount of aromatase mRNA and aromatase activity in 15 cases examined. No significant correlation was detected between the amount of aromatase mRNA or aromatase labeling index and the ER status. These results suggest that estrone and estradiol are produced in the human vena cava and that their production is mediated by aromatase and 17beta-HSD I, respectively but not all of these locally synthesized estrogens may not work directly in situ.  (+info)

  • Classification of mushroom ingestion, clinicians should know about the recurrent laryngeal nerve involvement superior vena cava with pulmonary hypertension or clinically obvious renal disease are discussed briefly. (
  • Persistent left superior vena cava (PLSVC) is the most common thoracic systemic venous drainage anomaly, occurring in 0.5% of the general population and in ≈10% of patients with other congenital cardiac anomalies. (