Plastics: Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Surgery, Plastic: The branch of surgery concerned with restoration, reconstruction, or improvement of defective, damaged, or missing structures.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.Bariatric Surgery: Surgical procedures aimed at affecting metabolism and producing major WEIGHT REDUCTION in patients with MORBID OBESITY.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.Plastic Embedding: The infiltrating of histological specimens with plastics, including acrylic resins, epoxy resins and polyethylene glycol, for support of the tissues in preparation for sectioning with a microtome.General Surgery: A specialty in which manual or operative procedures are used in the treatment of disease, injuries, or deformities.Thoracic Surgery: A surgical specialty concerned with diagnosis and treatment of disorders of the heart, lungs, and esophagus. Two major types of thoracic surgery are classified as pulmonary and cardiovascular.Cardiac Surgical Procedures: Surgery performed on the heart.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.Postoperative Period: The period following a surgical operation.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.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.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)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.)Thoracic Surgery, Video-Assisted: Endoscopic surgery of the pleural cavity performed with visualization via video transmission.Cataract Extraction: The removal of a cataractous CRYSTALLINE LENS from the eye.Surgery, Computer-Assisted: Surgical procedures conducted with the aid of computers. This is most frequently used in orthopedic and laparoscopic surgery for implant placement and instrument guidance. Image-guided surgery interactively combines prior CT scans or MRI images with real-time video.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)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.Surgery, Oral: A dental specialty concerned with the diagnosis and surgical treatment of disease, injuries, and defects of the human oral and maxillofacial region.Ambulatory Surgical Procedures: Surgery performed on an outpatient basis. It may be hospital-based or performed in an office or surgicenter.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.Reconstructive Surgical Procedures: Procedures used to reconstruct, restore, or improve defective, damaged, or missing structures.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.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.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.Intraoperative Care: Patient care procedures performed during the operation that are ancillary to the actual surgery. It includes monitoring, fluid therapy, medication, transfusion, anesthesia, radiography, and laboratory tests.Colorectal Surgery: A surgical specialty concerned with the diagnosis and treatment of disorders and abnormalities of the COLON; RECTUM; and ANAL CANAL.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.Pain, Postoperative: Pain during the period after surgery.Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.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.Perioperative Care: Interventions to provide care prior to, during, and immediately after surgery.Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Surgery Department, Hospital: Hospital department which administers all departmental functions and the provision of surgical diagnostic and therapeutic services.Neurosurgical Procedures: Surgery performed on the nervous system or its parts.Thoracic Surgical Procedures: Surgery performed on the thoracic organs, most commonly the lungs and the heart.Vascular Surgical Procedures: Operative procedures for the treatment of vascular disorders.Intraoperative Period: The period during a surgical operation.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.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.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.Gynecologic Surgical Procedures: Surgery performed on the female genitalia.Monitoring, Intraoperative: The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).Anesthesia, General: Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.Length of Stay: The period of confinement of a patient to a hospital or other health facility.Digestive System Surgical Procedures: Surgery performed on the digestive system or its parts.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Styrenes: Derivatives and polymers of styrene. They are used in the manufacturing of synthetic rubber, plastics, and resins. Some of the polymers form the skeletal structures for ion exchange resin beads.Waste Products: Debris resulting from a process that is of no further use to the system producing it. The concept includes materials discharged from or stored in a system in inert form as a by-product of vital activities. (From Webster's New Collegiate Dictionary, 1981)Video-Assisted Surgery: Endoscopic surgical procedures performed with visualization via video transmission. When real-time video is combined interactively with prior CT scans or MRI images, this is called image-guided surgery (see SURGERY, COMPUTER-ASSISTED).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)Polyvinyl Chloride: A polyvinyl resin used extensively in the manufacture of plastics, including medical devices, tubing, and other packaging. It is also used as a rubber substitute.Stapes Surgery: Surgery performed in which part of the STAPES, a bone in the middle ear, is removed and a prosthesis is placed to help transmit sound between the middle ear and inner ear.Gastric Bypass: Surgical procedure in which the STOMACH is transected high on the body. The resulting small proximal gastric pouch is joined to any parts of the SMALL INTESTINE by an end-to-side SURGICAL ANASTOMOSIS, depending on the amounts of intestinal surface being bypasses. This procedure is used frequently in the treatment of MORBID OBESITY by limiting the size of functional STOMACH, food intake, and food absorption.Blood Loss, Surgical: Loss of blood during a surgical procedure.Suture Techniques: Techniques for securing together the edges of a wound, with loops of thread or similar materials (SUTURES).Combined Modality Therapy: The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.Benzhydryl Compounds: Compounds which contain the methyl radical substituted with two benzene rings. Permitted are any substituents, but ring fusion to any of the benzene rings is not allowed.Polystyrenes: Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.Preoperative Period: The period before a surgical operation.Decompression, Surgical: A surgical operation for the relief of pressure in a body compartment or on a body part. (From Dorland, 28th ed)Microsurgery: The performance of surgical procedures with the aid of a microscope.Glass: Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.Orthopedics: A surgical specialty which utilizes medical, surgical, and physical methods to treat and correct deformities, diseases, and injuries to the skeletal system, its articulations, and associated structures.Abdomen: That portion of the body that lies between the THORAX and the PELVIS.Equipment Design: Methods of creating machines and devices.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Phacoemulsification: A procedure for removal of the crystalline lens in cataract surgery in which an anterior capsulectomy is performed by means of a needle inserted through a small incision at the temporal limbus, allowing the lens contents to fall through the dilated pupil into the anterior chamber where they are broken up by the use of ultrasound and aspirated out of the eye through the incision. (Cline, et al., Dictionary of Visual Science, 4th ed & In Focus 1993;1(1):1)Oral Surgical Procedures: Surgical procedures used to treat disease, injuries, and defects of the oral and maxillofacial region.Surgical Instruments: Hand-held tools or implements used by health professionals for the performance of surgical tasks.Cardiovascular Surgical Procedures: Surgery performed on the heart or blood vessels.Scintillation Counting: Detection and counting of scintillations produced in a fluorescent material by ionizing radiation.Polypropylenes: Propylene or propene polymers. Thermoplastics that can be extruded into fibers, films or solid forms. They are used as a copolymer in plastics, especially polyethylene. The fibers are used for fabrics, filters and surgical sutures.Pneumonectomy: The excision of lung tissue including partial or total lung lobectomy.Mammaplasty: Surgical reconstruction of the breast including both augmentation and reduction.Urologic Surgical Procedures: Surgery performed on the urinary tract or its parts in the male or female. For surgery of the male genitalia, UROLOGIC SURGICAL PROCEDURES, MALE is available.Thoracotomy: Surgical incision into the chest wall.Mohs Surgery: A surgical technique used primarily in the treatment of skin neoplasms, especially basal cell or squamous cell carcinoma of the skin. This procedure is a microscopically controlled excision of cutaneous tumors either after fixation in vivo or after freezing the tissue. Serial examinations of fresh tissue specimens are most frequently done.Operating Rooms: Facilities equipped for performing surgery.Recurrence: The return of a sign, symptom, or disease after a remission.Recovery of Function: A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.Anesthesia, Local: A blocking of nerve conduction to a specific area by an injection of an anesthetic agent.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.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)Failed Back Surgery Syndrome: A condition of persistent pain and discomfort in the BACK and the LEG following lumbar surgery, often seen in patients enrolled in pain centers.Patient Isolators: Equipment used to prevent contamination of and by patients, especially those with bacterial infections. This includes plastic surgical isolators and isolators used to protect immunocompromised patients.Anesthesia: A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.Cataract: Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Patient Selection: Criteria and standards used for the determination of the appropriateness of the inclusion of patients with specific conditions in proposed treatment plans and the criteria used for the inclusion of subjects in various clinical trials and other research protocols.Surgical Procedures, Minor: Surgery restricted to the management of minor problems and injuries; surgical procedures of relatively slight extent and not in itself hazardous to life. (Dorland, 28th ed & Stedman, 25th ed)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.Robotics: The application of electronic, computerized control systems to mechanical devices designed to perform human functions. Formerly restricted to industry, but nowadays applied to artificial organs controlled by bionic (bioelectronic) devices, like automated insulin pumps and other prostheses.Drainage: The removal of fluids or discharges from the body, such as from a wound, sore, or cavity.Laparotomy: Incision into the side of the abdomen between the ribs and pelvis.Pain Measurement: Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.Magnetic Resonance Imaging: 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.Cell Adhesion: Adherence of cells to surfaces or to other cells.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.Lumbar Vertebrae: VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.Food Packaging: Containers, packaging, and packaging materials for processed and raw foods and beverages. It includes packaging intended to be used for storage and also used for preparation of foods such as microwave food containers versus COOKING AND EATING UTENSILS. Packaging materials may be intended for food contact or designated non-contact, for example, shipping containers. FOOD LABELING is also available.Surgical Equipment: Nonexpendable apparatus used during surgical procedures. They are differentiated from SURGICAL INSTRUMENTS, usually hand-held and used in the immediate operative field.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.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.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.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.Tissue Adhesions: Pathological processes consisting of the union of the opposing surfaces of a wound.Perioperative Period: The time periods immediately before, during and following a surgical operation.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Colectomy: Excision of a portion of the colon or of the whole colon. (Dorland, 28th ed)Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Premedication: Preliminary administration of a drug preceding a diagnostic, therapeutic, or surgical procedure. The commonest types of premedication are antibiotics (ANTIBIOTIC PROPHYLAXIS) and anti-anxiety agents. It does not include PREANESTHETIC MEDICATION.Specialties, Surgical: Various branches of surgical practice limited to specialized areas.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Lens Implantation, Intraocular: Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.Laser Therapy: The use of photothermal effects of LASERS to coagulate, incise, vaporize, resect, dissect, or resurface tissue.Patient Satisfaction: The degree to which the individual regards the health care service or product or the manner in which it is delivered by the provider as useful, effective, or beneficial.Anesthetics, Local: Drugs that block nerve conduction when applied locally to nerve tissue in appropriate concentrations. They act on any part of the nervous system and on every type of nerve fiber. In contact with a nerve trunk, these anesthetics can cause both sensory and motor paralysis in the innervated area. Their action is completely reversible. (From Gilman AG, et. al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed) Nearly all local anesthetics act by reducing the tendency of voltage-dependent sodium channels to activate.Conversion to Open Surgery: Changing an operative procedure from an endoscopic surgical procedure to an open approach during the INTRAOPERATIVE PERIOD.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Heart Valve Diseases: Pathological conditions involving any of the various HEART VALVES and the associated structures (PAPILLARY MUSCLES and CHORDAE TENDINEAE).Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.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.Hemostasis, Surgical: Control of bleeding during or after surgery.Hospital Mortality: A vital statistic measuring or recording the rate of death from any cause in hospitalized populations.Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.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.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.Spine: The spinal or vertebral column.Recycling: The extraction and recovery of usable or valuable material from scrap or other discarded materials. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed.)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.Vitrectomy: Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.Arthroplasty, Replacement, Hip: Replacement of the hip joint.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.Mastectomy: Surgical procedure to remove one or both breasts.Operative Time: The duration of a surgical procedure in hours and minutes.Phenols: Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Esthetics: The branch of philosophy dealing with the nature of the beautiful. It includes beauty, esthetic experience, esthetic judgment, esthetic aspects of medicine, etc.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Phthalic Acids: A group of compounds that has the general structure of a dicarboxylic acid-substituted benzene ring. The ortho-isomer is used in dye manufacture. (Dorland, 28th ed)Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Neurosurgery: A surgical specialty concerned with the treatment of diseases and disorders of the brain, spinal cord, and peripheral and sympathetic nervous system.Orthognathic Surgical Procedures: Surgery performed to repair or correct the skeletal anomalies of the jaw and its associated dental and facial structures (e.g. CLEFT PALATE).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.Optical Fibers: Thin strands of transparent material, usually glass, that are used for transmitting light waves over long distances.Nerve Block: Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Foreign Bodies: Inanimate objects that become enclosed in the body.Strabismus: Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)Breast Neoplasms: Tumors or cancer of the human BREAST.Gastrectomy: Excision of the whole (total gastrectomy) or part (subtotal gastrectomy, partial gastrectomy, gastric resection) of the stomach. (Dorland, 28th ed)Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Arthroplasty, Replacement, Knee: Replacement of the knee joint.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.Radiotherapy, Adjuvant: Radiotherapy given to augment some other form of treatment such as surgery or chemotherapy. Adjuvant radiotherapy is commonly used in the therapy of cancer and can be administered before or after the primary treatment.Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.Craniotomy: Any operation on the cranium or incision into the cranium. (Dorland, 28th ed)Chemotherapy, Adjuvant: Drug therapy given to augment or stimulate some other form of treatment such as surgery or radiation therapy. Adjuvant chemotherapy is commonly used in the therapy of cancer and can be administered before or after the primary treatment.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.Surgical Sponges: Gauze material used to absorb body fluids during surgery. Referred to as GOSSYPIBOMA if accidentally retained in the body following surgery.Thoracoscopy: Endoscopic examination, therapy or surgery of the pleural cavity.Acrylonitrile: A highly poisonous compound used widely in the manufacture of plastics, adhesives and synthetic rubber.Hysterectomy: Excision of the uterus.Benchmarking: Method of measuring performance against established standards of best practice.Scoliosis: An appreciable lateral deviation in the normally straight vertical line of the spine. (Dorland, 27th ed)Mastectomy, Segmental: Removal of only enough breast tissue to ensure that the margins of the resected surgical specimen are free of tumor.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.Anesthesia Recovery Period: The period of emergence from general anesthesia, where different elements of consciousness return at different rates.Wound Healing: Restoration of integrity to traumatized tissue.Prosthesis Implantation: Surgical insertion of a prosthesis.Heart Valves: Flaps of tissue that prevent regurgitation of BLOOD from the HEART VENTRICLES to the HEART ATRIA or from the PULMONARY ARTERIES or AORTA to the ventricles.Polyethylenes: Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants.Outcome Assessment (Health Care): Research aimed at assessing the quality and effectiveness of health care as measured by the attainment of a specified end result or outcome. Measures include parameters such as improved health, lowered morbidity or mortality, and improvement of abnormal states (such as elevated blood pressure).Eyelids: Each of the upper and lower folds of SKIN which cover the EYE when closed.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)Pulmonary Surgical Procedures: Surgery performed on the lung.Sternotomy: Making an incision in the STERNUM.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.Arthroscopy: Endoscopic examination, therapy and surgery of the joint.Corneal Surgery, Laser: Surgical techniques on the CORNEA employing LASERS, especially for reshaping the CORNEA to correct REFRACTIVE ERRORS.Surgical Wound Dehiscence: Pathologic process consisting of a partial or complete disruption of the layers of a surgical wound.Vitreoretinal Surgery: Specialized ophthalmic technique used in the surgical repair and or treatment of disorders that include retinal tears or detachment; MACULAR HOLES; hereditary retinal disease; AIDS-related retinal infections; ocular tumors; MACULAR DEGENERATION; DIABETIC RETINOPATHY; and UVEITIS.Aortic Aneurysm, Abdominal: An abnormal balloon- or sac-like dilatation in the wall of the ABDOMINAL AORTA which gives rise to the visceral, the parietal, and the terminal (iliac) branches below the aortic hiatus at the diaphragm.Neoadjuvant Therapy: Preliminary cancer therapy (chemotherapy, radiation therapy, hormone/endocrine therapy, immunotherapy, hyperthermia, etc.) that precedes a necessary second modality of treatment.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.United StatesEmergencies: Situations or conditions requiring immediate intervention to avoid serious adverse results.Foreign-Body Reaction: Chronic inflammation and granuloma formation around irritating foreign bodies.Osteotomy: The surgical cutting of a bone. (Dorland, 28th ed)Refractive Surgical Procedures: Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.