Reoperation: A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Heart Valve Prosthesis: A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.Treatment Outcome: 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.Bioprosthesis: Prosthesis, usually heart valve, composed of biological material and whose durability depends upon the stability of the material after pretreatment, rather than regeneration by host cell ingrowth. Durability is achieved 1, mechanically by the interposition of a cloth, usually polytetrafluoroethylene, between the host and the graft, and 2, chemically by stabilization of the tissue by intermolecular linking, usually with glutaraldehyde, after removal of antigenic components, or the use of reconstituted and restructured biopolymers.Hemiarthroplasty: A partial joint replacement in which only one surface of the joint is replaced with a PROSTHESIS.Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.Retrospective Studies: 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.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.Follow-Up Studies: 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.Mitral Valve: The valve between the left atrium and left ventricle of the heart.Prosthesis Failure: Malfunction of implantation shunts, valves, etc., and prosthesis loosening, migration, and breaking.Heart Valve Diseases: Pathological conditions involving any of the various HEART VALVES and the associated structures (PAPILLARY MUSCLES and CHORDAE TENDINEAE).Cardiovascular Surgical Procedures: Surgery performed on the heart or blood vessels.Cardiac Surgical Procedures: Surgery performed on the heart.Femoral Neck Fractures: Fractures of the short, constricted portion of the thigh bone between the femur head and the trochanters. It excludes intertrochanteric fractures which are HIP FRACTURES.Aortic Valve Insufficiency: Pathological condition characterized by the backflow of blood from the ASCENDING AORTA back into the LEFT VENTRICLE, leading to regurgitation. It is caused by diseases of the AORTIC VALVE or its surrounding tissue (aortic root).Suture Techniques: Techniques for securing together the edges of a wound, with loops of thread or similar materials (SUTURES).Recurrence: The return of a sign, symptom, or disease after a remission.Mitral Valve Insufficiency: Backflow of blood from the LEFT VENTRICLE into the LEFT ATRIUM due to imperfect closure of the MITRAL VALVE. This can lead to mitral valve regurgitation.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.Aortic Aneurysm: An abnormal balloon- or sac-like dilatation in the wall of AORTA.Postoperative Hemorrhage: Hemorrhage following any surgical procedure. It may be immediate or delayed and is not restricted to the surgical wound.Pulmonary Valve: A valve situated at the entrance to the pulmonary trunk from the right ventricle.Tetralogy of Fallot: A combination of congenital heart defects consisting of four key features including VENTRICULAR SEPTAL DEFECTS; PULMONARY STENOSIS; RIGHT VENTRICULAR HYPERTROPHY; and a dextro-positioned AORTA. In this condition, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body often causing CYANOSIS.Discrete Subaortic Stenosis: A type of constriction that is caused by the presence of a fibrous ring (discrete type) below the AORTIC VALVE, anywhere between the aortic valve and the MITRAL VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Fracture Fixation, Internal: The use of internal devices (metal plates, nails, rods, etc.) to hold the position of a fracture in proper alignment.Device Removal: Removal of an implanted therapeutic or prosthetic device.Sternotomy: Making an incision in the STERNUM.Anastomosis, Surgical: Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end, or side-to-side.Colorectal Surgery: A surgical specialty concerned with the diagnosis and treatment of disorders and abnormalities of the COLON; RECTUM; and ANAL CANAL.Prosthesis-Related Infections: Infections resulting from the implantation of prosthetic devices. The infections may be acquired from intraoperative contamination (early) or hematogenously acquired from other sites (late).Laparoscopy: A procedure in which a laparoscope (LAPAROSCOPES) is inserted through a small incision near the navel to examine the abdominal and pelvic organs in the PERITONEAL CAVITY. If appropriate, biopsy or surgery can be performed during laparoscopy.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Recurrent Laryngeal Nerve Injuries: Traumatic injuries to the RECURRENT LARYNGEAL NERVE that may result in vocal cord dysfunction.Postoperative Care: The period of care beginning when the patient is removed from surgery and aimed at meeting the patient's psychological and physical needs directly after surgery. (From Dictionary of Health Services Management, 2d ed)Truncus Arteriosus: The arterial trunk arising from the fetal heart. During development, it divides into AORTA and the PULMONARY ARTERY.Length of Stay: The period of confinement of a patient to a hospital or other health facility.Survival Rate: The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.Thoracotomy: Surgical incision into the chest wall.Coronary Artery Bypass: Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.Surgical Wound Infection: Infection occurring at the site of a surgical incision.Diskectomy: Excision, in part or whole, of an INTERVERTEBRAL DISC. The most common indication is disk displacement or herniation. In addition to standard surgical removal, it can be performed by percutaneous diskectomy (DISKECTOMY, PERCUTANEOUS) or by laparoscopic diskectomy, the former being the more common.Endocarditis: Inflammation of the inner lining of the heart (ENDOCARDIUM), the continuous membrane lining the four chambers and HEART VALVES. It is often caused by microorganisms including bacteria, viruses, fungi, and rickettsiae. Left untreated, endocarditis can damage heart valves and become life-threatening.Hyperparathyroidism: A condition of abnormally elevated output of PARATHYROID HORMONE (or PTH) triggering responses that increase blood CALCIUM. It is characterized by HYPERCALCEMIA and BONE RESORPTION, eventually leading to bone diseases. PRIMARY HYPERPARATHYROIDISM is caused by parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. SECONDARY HYPERPARATHYROIDISM is increased PTH secretion in response to HYPOCALCEMIA, usually caused by chronic KIDNEY DISEASES.Arthroplasty, Replacement, Hip: Replacement of the hip joint.Intraoperative Complications: Complications that affect patients during surgery. They may or may not be associated with the disease for which the surgery is done, or within the same surgical procedure.Cardiac Valve Annuloplasty: A type of heart valve surgery that involves the repair, replacement, or reconstruction of the annuli of HEART VALVES. It includes shortening the circumference of the annulus to improve valve closing capacity and reinforcing the annulus as a step in more complex valve repairs.Periprosthetic Fractures: Fractures around joint replacement prosthetics or implants. They can occur intraoperatively or postoperatively.Hospital Mortality: A vital statistic measuring or recording the rate of death from any cause in hospitalized populations.Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Acellular Dermis: Remaining tissue from normal DERMIS tissue after the cells are removed.Surgical Wound Dehiscence: Pathologic process consisting of a partial or complete disruption of the layers of a surgical wound.Decompression, Surgical: A surgical operation for the relief of pressure in a body compartment or on a body part. (From Dorland, 28th ed)Prospective Studies: 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.Blepharoplasty: Plastic surgery of the eyelid. (Cline et al., Dictionary of Visual Science, 4th ed)Biliary Tract Surgical Procedures: Any surgical procedure performed on the biliary tract.Anastomotic Leak: Breakdown of the connection and subsequent leakage of effluent (fluids, secretions, air) from a SURGICAL ANASTOMOSIS of the digestive, respiratory, genitourinary, and cardiovascular systems. Most common leakages are from the breakdown of suture lines in gastrointestinal or bowel anastomosis.Spinal Fusion: Operative immobilization or ankylosis of two or more vertebrae by fusion of the vertebral bodies with a short bone graft or often with diskectomy or laminectomy. (From Blauvelt & Nelson, A Manual of Orthopaedic Terminology, 5th ed, p236; Dorland, 28th ed)Rheumatic Heart Disease: Cardiac manifestation of systemic rheumatological conditions, such as RHEUMATIC FEVER. Rheumatic heart disease can involve any part the heart, most often the HEART VALVES and the ENDOCARDIUM.Replantation: Restoration of an organ or other structure to its original site.Surgical Procedures, Minimally Invasive: Procedures that avoid use of open, invasive surgery in favor of closed or local surgery. These generally involve use of laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or similar device.Heart Septal Defects, Ventricular: Developmental abnormalities in any portion of the VENTRICULAR SEPTUM resulting in abnormal communications between the two lower chambers of the heart. Classification of ventricular septal defects is based on location of the communication, such as perimembranous, inlet, outlet (infundibular), central muscular, marginal muscular, or apical muscular defect.Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.Kaplan-Meier Estimate: A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)Tissue Adhesions: Pathological processes consisting of the union of the opposing surfaces of a wound.Blood Vessel Prosthesis Implantation: Surgical insertion of BLOOD VESSEL PROSTHESES to repair injured or diseased blood vessels.Vascular Surgical Procedures: Operative procedures for the treatment of vascular disorders.Blood Vessel Prosthesis: Device constructed of either synthetic or biological material that is used for the repair of injured or diseased blood vessels.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Ileostomy: Surgical creation of an external opening into the ILEUM for fecal diversion or drainage. This replacement for the RECTUM is usually created in patients with severe INFLAMMATORY BOWEL DISEASES. Loop (continent) or tube (incontinent) procedures are most often employed.Lumbar Vertebrae: VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.Sternum: A long, narrow, and flat bone commonly known as BREASTBONE occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head, and neck.Polytetrafluoroethylene: Homopolymer of tetrafluoroethylene. Nonflammable, tough, inert plastic tubing or sheeting; used to line vessels, insulate, protect or lubricate apparatus; also as filter, coating for surgical implants or as prosthetic material. Synonyms: Fluoroflex; Fluoroplast; Ftoroplast; Halon; Polyfene; PTFE; Tetron.Internal Fixators: Internal devices used in osteosynthesis to hold the position of the fracture in proper alignment. By applying the principles of biomedical engineering, the surgeon uses metal plates, nails, rods, etc., for the correction of skeletal defects.Jehovah's Witnesses: Members of a religious denomination founded in the United States during the late 19th century in which active evangelism is practiced, the imminent approach of the millennium is preached, and war and organized government authority in matters of conscience are strongly opposed (from American Heritage Dictionary of the English Language, 4th ed). Jehovah's Witnesses generally refuse blood transfusions and other blood-based treatments based on religious belief.Aortitis: Inflammation of the wall of the AORTA.Mitral Valve Stenosis: Narrowing of the passage through the MITRAL VALVE due to FIBROSIS, and CALCINOSIS in the leaflets and chordal areas. This elevates the left atrial pressure which, in turn, raises pulmonary venous and capillary pressure leading to bouts of DYSPNEA and TACHYCARDIA during physical exertion. RHEUMATIC FEVER is its primary cause.Transposition of Great Vessels: A congenital cardiovascular malformation in which the AORTA arises entirely from the RIGHT VENTRICLE, and the PULMONARY ARTERY arises from the LEFT VENTRICLE. Consequently, the pulmonary and the systemic circulations are parallel and not sequential, so that the venous return from the peripheral circulation is re-circulated by the right ventricle via aorta to the systemic circulation without being oxygenated in the lungs. This is a potentially lethal form of heart disease in newborns and infants.Drainage: The removal of fluids or discharges from the body, such as from a wound, sore, or cavity.Esotropia: A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.Digestive System Fistula: An abnormal passage communicating between any components of the digestive system, or between any part of the digestive system and surrounding organ(s).Postoperative Period: The period following a surgical operation.Cardiopulmonary Bypass: Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.Sciatica: A condition characterized by pain radiating from the back into the buttock and posterior/lateral aspects of the leg. Sciatica may be a manifestation of SCIATIC NEUROPATHY; RADICULOPATHY (involving the SPINAL NERVE ROOTS; L4, L5, S1, or S2, often associated with INTERVERTEBRAL DISK DISPLACEMENT); or lesions of the CAUDA EQUINA.Mediastinitis: Inflammation of the mediastinum, the area between the pleural sacs.Cystic Duct: The duct that is connected to the GALLBLADDER and allows the emptying of bile into the COMMON BILE DUCT.Tricuspid Valve Insufficiency: Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.Gastrectomy: Excision of the whole (total gastrectomy) or part (subtotal gastrectomy, partial gastrectomy, gastric resection) of the stomach. (Dorland, 28th ed)Cholecystostomy: Establishment of an opening into the gallbladder either for drainage or surgical communication with another part of the digestive tract, usually the duodenum or jejunum.Ventricular Outflow Obstruction: Occlusion of the outflow tract in either the LEFT VENTRICLE or the RIGHT VENTRICLE of the heart. This may result from CONGENITAL HEART DEFECTS, predisposing heart diseases, complications of surgery, or HEART NEOPLASMS.Pericardium: A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.Hernia, Hiatal: STOMACH herniation located at or near the diaphragmatic opening for the ESOPHAGUS, the esophageal hiatus.Spinal Stenosis: Narrowing of the spinal canal.Hip Prosthesis: Replacement for a hip joint.Fractures, Ununited: A fracture in which union fails to occur, the ends of the bone becoming rounded and eburnated, and a false joint occurs. (Stedman, 25th ed)Gastroplasty: Surgical procedures involving the STOMACH and sometimes the lower ESOPHAGUS to correct anatomical defects, or to treat MORBID OBESITY by reducing the size of the stomach. There are several subtypes of bariatric gastroplasty, such as vertical banded gastroplasty, silicone ring vertical gastroplasty, and horizontal banded gastroplasty.Fundoplication: Mobilization of the lower end of the esophagus and plication of the fundus of the stomach around it (fundic wrapping) in the treatment of GASTROESOPHAGEAL REFLUX that may be associated with various disorders, such as hiatal hernia. (From Dorland, 28th ed)Parathyroid Neoplasms: Tumors or cancer of the PARATHYROID GLANDS.Aneurysm, Dissecting: Aneurysm caused by a tear in the TUNICA INTIMA of a blood vessel leading to interstitial HEMORRHAGE, and splitting (dissecting) of the vessel wall, often involving the AORTA. Dissection between the intima and media causes luminal occlusion. Dissection at the media, or between the media and the outer adventitia causes aneurismal dilation.Anemia, Hemolytic: A condition of inadequate circulating red blood cells (ANEMIA) or insufficient HEMOGLOBIN due to premature destruction of red blood cells (ERYTHROCYTES).Surgical Mesh: Any woven or knit material of open texture used in surgery for the repair, reconstruction, or substitution of tissue. The mesh is usually a synthetic fabric made of various polymers. It is occasionally made of metal.Sutures: Materials used in closing a surgical or traumatic wound. (From Dorland, 28th ed)Tissue Adhesives: Substances used to cause adherence of tissue to tissue or tissue to non-tissue surfaces, as for prostheses.Treatment Failure: A measure of the quality of health care by assessment of unsuccessful results of management and procedures used in combating disease, in individual cases or series.Fracture Healing: The physiological restoration of bone tissue and function after a fracture. It includes BONY CALLUS formation and normal replacement of bone tissue.Vagotomy, Proximal Gastric: Vagal denervation of that part of the STOMACH lined with acid-secreting mucosa (GASTRIC MUCOSA) containing the GASTRIC PARIETAL CELLS. Since the procedure leaves the vagal branches to the antrum and PYLORUS intact, it circumvents gastric drainage required with truncal vagotomy techniques.Knee Prosthesis: Replacement for a knee joint.Equipment Failure: Failure of equipment to perform to standard. The failure may be due to defects or improper use.Marfan Syndrome: An autosomal dominant disorder of CONNECTIVE TISSUE with abnormal features in the heart, the eye, and the skeleton. Cardiovascular manifestations include MITRAL VALVE PROLAPSE, dilation of the AORTA, and aortic dissection. Other features include lens displacement (ectopia lentis), disproportioned long limbs and enlarged DURA MATER (dural ectasia). Marfan syndrome is associated with mutations in the gene encoding fibrillin, a major element of extracellular microfibrils of connective tissue.Bone Screws: Specialized devices used in ORTHOPEDIC SURGERY to repair bone fractures.Bone Nails: Rods of bone, metal, or other material used for fixation of the fragments or ends of fractured bones.Jejunostomy: Surgical formation of an opening through the ABDOMINAL WALL into the JEJUNUM, usually for enteral hyperalimentation.Fracture Fixation, Intramedullary: The use of nails that are inserted into bone cavities in order to keep fractured bones together.Graft Occlusion, Vascular: Obstruction of flow in biological or prosthetic vascular grafts.Pancreatectomy: Surgical removal of the pancreas. (Dorland, 28th ed)Tibial FracturesAortic Valve Stenosis: A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Debridement: The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. (Dorland, 27th ed)Actuarial Analysis: The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs.Life Tables: Summarizing techniques used to describe the pattern of mortality and survival in populations. These methods can be applied to the study not only of death, but also of any defined endpoint such as the onset of disease or the occurrence of disease complications.Second-Look Surgery: A followup operation to examine the outcome of the previous surgery and other treatments, such as chemotherapy or radiation therapy.Hematoma, Epidural, Cranial: Accumulation of blood in the EPIDURAL SPACE between the SKULL and the DURA MATER, often as a result of bleeding from the MENINGEAL ARTERIES associated with a temporal or parietal bone fracture. Epidural hematoma tends to expand rapidly, compressing the dura and underlying brain. Clinical features may include HEADACHE; VOMITING; HEMIPARESIS; and impaired mental function.Methods: A series of steps taken in order to conduct research.Pancreaticoduodenectomy: The excision of the head of the pancreas and the encircling loop of the duodenum to which it is connected.Hip Fractures: Fractures of the FEMUR HEAD; the FEMUR NECK; (FEMORAL NECK FRACTURES); the trochanters; or the inter- or subtrochanteric region. Excludes fractures of the acetabulum and fractures of the femoral shaft below the subtrochanteric region (FEMORAL FRACTURES).Emergency Treatment: First aid or other immediate intervention for accidents or medical conditions requiring immediate care and treatment before definitive medical and surgical management can be procured.Polyethylene Terephthalates: Polyester polymers formed from terephthalic acid or its esters and ethylene glycol. They can be formed into tapes, films or pulled into fibers that are pressed into meshes or woven into fabrics.Chi-Square Distribution: A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.Survival Analysis: A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.Anastomosis, Roux-en-Y: A Y-shaped surgical anastomosis of any part of the digestive system which includes the small intestine as the eventual drainage site.Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Dilatation: The act of dilating.Echocardiography, Transesophageal: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.Mitral Valve Prolapse: Abnormal protrusion or billowing of one or both of the leaflets of MITRAL VALVE into the LEFT ATRIUM during SYSTOLE. This allows the backflow of blood into left atrium leading to MITRAL VALVE INSUFFICIENCY; SYSTOLIC MURMURS; or CARDIAC ARRHYTHMIA.Aneurysm, Infected: Aneurysm due to growth of microorganisms in the arterial wall, or infection arising within preexisting arteriosclerotic aneurysms.Blood Loss, Surgical: Loss of blood during a surgical procedure.Thromboembolism: Obstruction of a blood vessel (embolism) by a blood clot (THROMBUS) in the blood stream.Hemorrhage: Bleeding or escape of blood from a vessel.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Saphenous Vein: The vein which drains the foot and leg.Recovery of Function: A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.Multivariate Analysis: A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.Blepharoptosis: Drooping of the upper lid due to deficient development or paralysis of the levator palpebrae muscle.Neoplasm Recurrence, Local: The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.Vascular Patency: The degree to which BLOOD VESSELS are not blocked or obstructed.Intervertebral Disc Displacement: An INTERVERTEBRAL DISC in which the nucleus pulposus has protruded through surrounding fibrocartilage. This occurs most frequently in the lower lumbar region.Hemostatic Techniques: Techniques for controlling bleeding.Intraoperative Period: The period during a surgical operation.Obesity, Morbid: The condition of weighing two, three, or more times the ideal weight, so called because it is associated with many serious and life-threatening disorders. In the BODY MASS INDEX, morbid obesity is defined as having a BMI greater than 40.0 kg/m2.Time: The dimension of the physical universe which, at a given place, orders the sequence of events. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Aneurysm, False: Not an aneurysm but a well-defined collection of blood and CONNECTIVE TISSUE outside the wall of a blood vessel or the heart. It is the containment of a ruptured blood vessel or heart, such as sealing a rupture of the left ventricle. False aneurysm is formed by organized THROMBUS and HEMATOMA in surrounding tissue.Neurosurgical Procedures: Surgery performed on the nervous system or its parts.Dilatation, Pathologic: The condition of an anatomical structure's being dilated beyond normal dimensions.Colectomy: Excision of a portion of the colon or of the whole colon. (Dorland, 28th ed)Aortic Aneurysm, Thoracic: An abnormal balloon- or sac-like dilatation in the wall of the THORACIC AORTA. This proximal descending portion of aorta gives rise to the visceral and the parietal branches above the aortic hiatus at the diaphragm.Digestive System Surgical Procedures: Surgery performed on the digestive system or its parts.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Reconstructive Surgical Procedures: Procedures used to reconstruct, restore, or improve defective, damaged, or missing structures.Cementation: The joining of objects by means of a cement (e.g., in fracture fixation, such as in hip arthroplasty for joining of the acetabular component to the femoral component). In dentistry, it is used for the process of attaching parts of a tooth or restorative material to a natural tooth or for the attaching of orthodontic bands to teeth by means of an adhesive.Bone Plates: Implantable fracture fixation devices attached to bone fragments with screws to bridge the fracture gap and shield the fracture site from stress as bone heals. (UMDNS, 1999)Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Double Outlet Right Ventricle: Incomplete transposition of the great vessels in which both the AORTA and the PULMONARY ARTERY arise from the RIGHT VENTRICLE. The only outlet of the LEFT VENTRICLE is a large ventricular septal defect (VENTRICULAR SEPTAL DEFECTS or VSD). The various subtypes are classified by the location of the septal defect, such as subaortic, subpulmonary, or noncommitted.Joint Prosthesis: Prostheses used to partially or totally replace a human or animal joint. (from UMDNS, 1999)Hernia, Inguinal: An abdominal hernia with an external bulge in the GROIN region. It can be classified by the location of herniation. Indirect inguinal hernias occur through the internal inguinal ring. Direct inguinal hernias occur through defects in the ABDOMINAL WALL (transversalis fascia) in Hesselbach's triangle. The former type is commonly seen in children and young adults; the latter in adults.Laparotomy: Incision into the side of the abdomen between the ribs and pelvis.Common Bile Duct: The largest bile duct. It is formed by the junction of the CYSTIC DUCT and the COMMON HEPATIC DUCT.Registries: The systems and processes involved in the establishment, support, management, and operation of registers, e.g., disease registers.Aortic Diseases: Pathological processes involving any part of the AORTA.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Thyroidectomy: Surgical removal of the thyroid gland. (Dorland, 28th ed)Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Hip Joint: The joint that is formed by the articulation of the head of FEMUR and the ACETABULUM of the PELVIS.Aortography: Radiographic visualization of the aorta and its branches by injection of contrast media, using percutaneous puncture or catheterization procedures.Proctocolectomy, Restorative: A surgical procedure involving the excision of the COLON and RECTUM and the formation of an ILEOANAL RESERVOIR (pouch). In patients with intestinal diseases, such as ulcerative colitis, this procedure avoids the need for an OSTOMY by allowing for transanal defecation.Surgical Procedures, Elective: Surgery which could be postponed or not done at all without danger to the patient. Elective surgery includes procedures to correct non-life-threatening medical problems as well as to alleviate conditions causing psychological stress or other potential risk to patients, e.g., cosmetic or contraceptive surgery.Parathyroid Glands: Two pairs of small oval-shaped glands located in the front and the base of the NECK and adjacent to the two lobes of THYROID GLAND. They secrete PARATHYROID HORMONE that regulates the balance of CALCIUM; PHOSPHORUS; and MAGNESIUM in the body.Logistic Models: Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.Endarterectomy, Carotid: The excision of the thickened, atheromatous tunica intima of a carotid artery.Arthroplasty, Replacement: Partial or total replacement of a joint.Aorta, Thoracic: The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.Endocarditis, Bacterial: Inflammation of the ENDOCARDIUM caused by BACTERIA that entered the bloodstream. The strains of bacteria vary with predisposing factors, such as CONGENITAL HEART DEFECTS; HEART VALVE DISEASES; HEART VALVE PROSTHESIS IMPLANTATION; or intravenous drug use.Prosthesis Implantation: Surgical insertion of a prosthesis.Surgical Flaps: Tongues of skin and subcutaneous tissue, sometimes including muscle, cut away from the underlying parts but often still attached at one end. They retain their own microvasculature which is also transferred to the new site. They are often used in plastic surgery for filling a defect in a neighboring region.Proportional Hazards Models: Statistical models used in survival analysis that assert that the effect of the study factors on the hazard rate in the study population is multiplicative and does not change over time.Veins: The vessels carrying blood away from the capillary beds.Preoperative Care: Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)Peptic Ulcer Perforation: Penetration of a PEPTIC ULCER through the wall of DUODENUM or STOMACH allowing the leakage of luminal contents into the PERITONEAL CAVITY.Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Pancreatic Fistula: Abnormal passage communicating with the PANCREAS.Surgical Procedures, Operative: Operations carried out for the correction of deformities and defects, repair of injuries, and diagnosis and cure of certain diseases. (Taber, 18th ed.)Oculomotor Muscles: The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.Bone Cements: Adhesives used to fix prosthetic devices to bones and to cement bone to bone in difficult fractures. Synthetic resins are commonly used as cements. A mixture of monocalcium phosphate, monohydrate, alpha-tricalcium phosphate, and calcium carbonate with a sodium phosphate solution is also a useful bone paste.Arthroplasty, Replacement, Knee: Replacement of the knee joint.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Hemostatics: Agents acting to arrest the flow of blood. Absorbable hemostatics arrest bleeding either by the formation of an artificial clot or by providing a mechanical matrix that facilitates clotting when applied directly to the bleeding surface. These agents function more at the capillary level and are not effective at stemming arterial or venous bleeding under any significant intravascular pressure.Acetabulum: The part of the pelvis that comprises the pelvic socket where the head of FEMUR joins to form HIP JOINT (acetabulofemoral joint).Laminectomy: A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.