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Biomedical subjects

W M Abbott

Publications and source records attributed to W M Abbott.

At least 163 records · Page 9Linked to original sources
PubMed1982

Safe management of patients with simultaneously occurring prostatism and abdominal aortic aneurysm.

In patients who present with both an abdominal aortic aneurysm and signs or symptoms of urinary obstruction from prostatic hypertrophy, prostatectomy should be performed first if the patient's condition permits. Since bleeding from the site of prostatic resection is rare, the interval between prostatic and subsequent aneurysm operations need not be long. One to 2 weeks after hematuria disappears should be sufficient. If clinical conditions prompt emergency operation for a abdominal aortic aneurysm in a patient with prostatism, blood spectrum antibiotics should be used which include coverage for enterococci. Subsequent prostatectomy should be delayed as long as possible unless the patient cannot void or develops a urinary tract infection that cannot be cleared with appropriate antibiotics. Broad spectrum antibodies during and after prostate surgery, in this instance, are mandatory.

Aged↗
PubMed1982

Arterial embolism: a 44 year perspective.

Forty-four years of experience with arterial embolism is reviewed. Patients presenting with this problem are increasingly older, more frequently female, and usually have atherosclerotic coronary artery disease. Atrial fibrillation is found in a high percentage of these patients. Mortality after embolism is decreasing but remains high (25 percent). Limb salvage is usually achieved (87 percent) but has improved little since the balloon embolectomy catheter became available. Prompt treatment, careful patient selection for operation, and anticoagulation remain the keys to successful outcome in the management of patients with arterial embolism.

Age Factors↗
PubMed1982

Current PTFE grafts: a biomechanical, scanning electron, and light microscopic evaluation.

Two currently available brands of PTFE grafts (Goretex and Impra) were studied in a canine femoral artery model to determine whether changes in the manufacturing processes of the two grafts, which increased their strength, had altered the biophysical properties and the histological reactivity of either graft. Both grafts were found to be similar except for differences in their suturability. Their in vivo dynamic compliances were almost identical (1.2 +/- 0.35 vs. 1.2 +/- 0.45). (Scanning electron microscopy showed endothelialization of the grafts only adjacent to the anastomoses, and light microscopy demonstrated similar degrees of histologic incorporation by the host tissues, though of slower tempo than that previously described. These results are examined and discussed with regard to the suitability of this model for characterizing new arterial prostheses of small to medium diameter.

Animals↗
PubMed1981

The role of two noninvasive tests in deep venous thrombosis.

A prospective study was performed to evaluate the accuracy and usefulness of two noninvasive modalities, Doppler ultrasonography and segmental air plethysmography, in the detection of deep vein thrombosis. Over a two-year period, 211 limbs were studied among 167 patients, and the results were compared with venography. Doppler ultrasonography was found to be very accurate in detecting above-knee thrombi (sensitivity: 92.4%, specificity: 90.7%) while plethysmography was found to be much less accurate (sensitivity: 77.3%, specificity: 62.4%). The results were also assessed according to the mode of patient presentation. Doppler ultrasonography was found to be very useful in symptomatic out-patients, because of the lower incidence of calf thrombi, and less accurate in symptomatic inpatients and in high risk in-patients being screened. The clinical usefulness of noninvasive detection of venous thrombosis is discussed with regard to the incidence of disease and the site of thrombosis in different patient groups under study, and recommendations are made based on these results.

Evaluation Studies as Topic↗
PubMed1981

The value of electrocardiogram monitoring during treadmill testing for peripheral vascular disease.

In evaluating the arterial hemodynamics of the lower extremities in patients with peripheral vascular disease, the treadmill exercise test offers useful information concerning the peripheral circulation. The addition of electrocardiographic (EKG) monitoring during the treadmill examination provides a method of estimating the effectiveness of coronary circulation. In three groups of patients studied, the results demonstrated that EKG monitoring during the treadmill exercise test will reveal previously unsuspected arrhythmias and ischemia. Thus the safety of the patient is enhanced. In patients followed through the operative period, there was a high correlation between exercise-induced EKG changes and perioperative cardiac problems. The value of EKG monitoring during treadmill testing is clear and offers predictive information to the surgeon contemplating a revascularization procedure.

Arrhythmias, Cardiac↗
PubMed1980

Matched elastic properties and successful arterial grafting.

Clinical results from medium- and small-caliber arterial bypass grafts are unsatisfactory. Since elastic properties of grafts tested experimentally have been correlated with patency results, the compliance of the human femoral artery was compared with grafts currently in use: human saphenous vein (HSV), knitted Dacron (DAC), glutaraldehyde-treated umbilical cord vein (DBM), bovine heterograft, and expanded polytetrafluoroethylene (PTFE). This was correlated with clinical patency data for the different conduits in the femoropopliteal position. Increased patency correlated with a decreasing disparity between host artery and graft compliance. After two years, patency rates of the more compliant materials (HSV, DBM) exceeded 80%, while less than 45% of the incompliant grafts (DAC, PTFE) remained patent. Thus, clinical performance with synthetic grafts might be improved by use of prostheses in which the viscoelastic characteristics match those of arteries more closely.

Actuarial Analysis↗
PubMed1980

Percutaneous transluminal angioplasty: surgeon's view.

The balloon-tipped catheter for percutaneous transluminal angioplasty (PTA) is a potentially dangerous weapon. Safe use requires considerable technical skill. Complications have already caused significant risk to, and loss of, limbs and life. Although there is no question that the incidence of successful dilatation in competent hands is quite high, the risks of complication are still not completely known. Any new procedure must be compared with existing effective modes of treatment, in this case, surgical revascularization. Therefore, this new procedure must be examined and compared in terms of acute hemodynamic effectiveness, mortality and morbidity, specific indications, long-term results (durability), and consequences of long-term failure. Pertinent surgical experience is reported to provide data for this comparison and information from which some predictions about percutaneous angioplasty can be made. Although complete information about these issues is needed before we can confidently accept balloon catheter angioplasty as a therapeutic procedure and assign it its proper role, cautious and judicious application of angioplasty should proceed with some definite guidelines.

Arteriosclerosis↗
PubMed1980

Diagnosis of deep venous thrombosis in the outpatient by venography.

One hundred and two patients, presenting at the outpatient departments of two Boston teaching hospitals, underwent clinical examination and venography. History, physical examination and presence of risk factors were unreliable in the diagnosis of deep venous thrombosis. Seventy-two per cent of the patients with deep venous thrombosis had a proximal extension of the thrombus to the femoral vein or higher. The outpatient with deep venous thrombosis appears to differ from the more frequently studied inpatient in the time of diagnosis and its anatomic extent. The high incidence of false-positive clinical examination results has important cost-benefit implications.

Adult↗
PubMed1979

Variable manifestations of vascular injury during lumbar disk surgery.

Major vascular injury is an unusual but well-recognized complication of lumbar disk surgery. Clinical manifestation of such injuries may be extremely variable. Isolated arterial laceration is most common, with early manifestation due to retroperitoneal hemorrhage. There are often few external signs of blood loss, however, and the diagnosis may not be recognized initially. Formation of an arteriovenous fistula or false aneurysm produces even fewer early signs, and diagnosis is often delayed for weeks or years. Six cases are described that illustrate the full spectrum of acute and chronic manifestations of such injuries. Two cases of acute hemorrhage due to arterial trauma were seen; one case was recognized intraoperatively and one in the recovery room. In four cases arteriovenous fistulae developed and were diagnosed from eight hours to eight years postoperatively. Two cases also had associated false aneurysms, one the probable source of pulmonary emboli and one the principal manifestation of the vascular injury.

Abdomen↗
PubMed1979

Intraoperative autotransfusion in major vascular surgery.

The use of intraoperative autotransfusion provides a safe and cost-effective means of salvaging operative blood loss and reducing or eliminating the use of stored homologous bank blood with its inherent difficulties and risks. The risk of disease transmission or various reactions is minimized. Autotransfusion provides a readily available, more physiologic, and at times life-saving source of blood for patients with rare blood types or patients in whom time does not permit adequate cross-matching. This technique is acceptable to most sects of Jehovah's Witnesses, who normally refuse homologous blood. Our experience during the past six years with autotransfusion in major vascular surgery reveals a mean slavage equivalent to five units of blood loss, and avoidance of using any bank blood in almost half of elective patients. No significant problems occurred due to hemolysis, coagulation abnormalities, or particulate/air emboli, nor any morbidity or mortality specifically related to autotransfusion. We conclude that wider and more frequent use of autotransfusion technics is appropriate.

Adult↗
PubMed1979

In vivo measurement of blood vessel wall thickness.

To understand the mechanical properties of arteries and vascular grafts, it is crucial that the wall thickness in these vessels be known. Unfortunately, all availble methods for measuring this parameter require the removal of the vessel, which precludes the study of such vessels as a function of time. A new radiographic technique for measuring the wall thickness of arteries and vascular grafts in vivo, utilizing contrast materials injected into the vessel lumen and applied to the outer surface of the vessel, is described. Radiographs are obtained with a portable X-ray machine and analyzed using a calibrated microscope. The technique has been successfully applied to the in vivo measurement of wall thickness in canine arteries, veins, and experimental vascular grafts. It is concluded that the method provides better than 95% accuracy in a variety of vessels and that it can be used to study changes in vascular grafts after their implantation into the arterial circulation.

Angiography↗
PubMed1979

Experience with a noninvasive evaluation for cerebral vascular disease.

This report describes a newly developed noninvasive method for extracranial cerebrovascular evaluation. Two hundred consecutive cases were studied at the Massachusetts General Hospital and matched with clinical and angiographic findings. There were three false negative and five false positive results. Two ulcerated plaques without stenosis were not detected. Management routes for different groups of patients with central nervous system symptoms are outlined. We emphasize the usefulness of monitoring postoperative ophthalmic artery pressure to aid in the early detection of carotid occlusion in patients developing neurologic symptoms following carotid endarterectomy.

Angiography↗
PubMed1978

Hemodynamic studies of the audiofrequency analysis of carotid bruits.

The contribution of carotid audiofrequency analysis to the noninvasive diagnosis of carotid arterial lesions requires clarification. Carotid arterial stenoses were simulated in the dog and the following measurements were made: proximal and distal arterial pressure, blood flow, percent area reduction, and carotid audiofrequency analysis. A 40% area reduction produced a systolic bruit but no interference with flow or pressure. A 60% area reduction produced a pansystolic bruit and a reduction in peak systolic flow (precritical stenosis). A 70% area reduction produced a systolic bruit that extended into diastole, a reduction in mean blood flow, and an increased pressure gradient (critical stenosis). At total occlusion, there was no recordable heart sound or bruit. Carotid audiofrequency analysis can establish the hemodynamic importance of a carotid artery lesion and it is an essential component of any noninvasive examination.

Animals↗
PubMed1978

Rational management of the asymptomatic carotid bruit.

A noninvasive cerebrovascular evaluation has been devised that combines three separate but complimentary procedures: ocular pneumoplethysmography (OPPG), carotid audiofrequency analysis (CAA), and cerebral Doppler analysis. This evaluation has proven particularly useful in examination of the asymptomatic carotid bruit, and the management of such patients is aided by noninvasive testing. Patients with a poorly compensated stenosis (reduced OPPG) are all considered candidates for angiography and surgery. For patients with a well-compensated (normal OPPG) but surgically important stenosis (abnormal CAA or Doppler), angiography and surgery are recommended in selected patients. Angiography and/or surgery are believed safely withheld in all remaining patients. The reliability and effectiveness of this approach is evaluated in a series of 100 consecutive patients with an asymptomatic carotid bruit. There were no false-positive results and only known false-negative interpretation.

Adult↗