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Biomedical subjects

H L Bush

Publications and source records attributed to H L Bush.

At least 55 records · Page 3Linked to original sources
PubMed1984

Luminal release of prostacyclin and thromboxane A2 by arteries distal to small-caliber prosthetic grafts.

Myointimal hyperplasia distal to prosthetic grafts may be due to a local imbalance of prostacyclin and thromboxane A2 that exaggerates platelet adherence. This study evaluated prostacyclin and thromboxane A2 production by arteries distal to prosthetic grafts. In 12 dogs, control segments of both iliac arteries were excised and a 5 cm segment of polytetrafluoroethylene was grafted end to end. One iliac artery was circumferentially dissected from the distal anastomosis to the inguinal ligament. The contralateral artery was not dissected. Of the 24 grafts, 19 remained patent and the arteries distal to these grafts were studied. After excision, each artery was analyzed for its ability to produce prostacyclin and thromboxane A2. Our data indicate that the luminal surface of a normal artery spontaneously produces both prostacyclin and thromboxane A2 and that the arterial wall distal to a prosthetic graft produces increased levels of these arachidonic acid metabolites. However, only those arteries not surgically dissected maintain a normal balance of prostacyclin and thromboxane A2. The dissected artery may thus be more susceptible to platelet interaction and myointimal hyperplasia.

Animals↗
PubMed1983

Direct venous surgery for venous valvular insufficiency of the lower extremity.

Seven patients had severe deep venous insufficiency and recurrent ulceration in eight lower extremities. All incompetent perforating veins had been previously ligated. All limbs were evaluated by dynamic venous pressure measurements. The venous pressure reduction with exercise was recorded, as well as the recovery time. The most accurate indicator of venous valvular incompetence was a short postexercise recovery time. Abnormal hemodynamic findings were correlated with ascending and descending venographic findings. Based on these anatomic and pathophysiologic abnormalities, patients underwent valvular transposition, superficial femoral vein valvuloplasty, or superficial femoral vein ligation. Immediate postoperative recovery time (mean +/- SEM) was improved to 34.5 +/- 18.3 s from 7.9 +/- 2.9 s preoperatively. Postoperative venography demonstrated patency of all anastomoses and absence of reflux into previously incompetent venous systems. All limbs were symptomatically improved after operation, and no venous thrombosis or pulmonary emboll developed. Persistent ulceration, however, continued in one limb.

Femoral Vein↗
PubMed1983

Combined operative angiodilation and arterial reconstruction for limb salvage.

Fifteen high-risk patients with threatened limb loss underwent combined operative iliac angiodilation and infrainguinal vascular reconstruction for iliac and femoropopliteal occlusive disease. The patients were poor candidates for combined surgical inflow and outflow reconstruction because of associated cardiopulmonary disease. The mean systolic pressure gradient across the iliac stenosis was 34 +/- 5 mm Hg. Iliac artery angiodilation was accomplished intraoperatively and reduced all gradients to zero. Stenoses in the distal portion of the deep femoral artery were endarterectomized in nine patients, and six cross-femoral and six distal popliteal or tibial grafts were constructed. Life-table analysis at 36 months showed iliac patency in 86% of cases and successful distal reconstruction in 76%. Our limb salvage rate of 86% suggests that combined intraoperative angiodilation by the angiographer and arterial reconstruction by the vascular surgeon may provide effective therapy for high-risk patients.

Actuarial Analysis↗
PubMed1983

Distal in situ saphenous vein grafts for limb salvage. Increased operative blood flow and postoperative patency.

Early failure remains a major obstacle to successful distal bypass surgery using vein grafts for limb salvage. Thirty distal bypass graft procedures were performed for limb salvage using the in situ technique. Grafts were anastomosed to the distal popliteal artery in 13 patients and to the infrapopliteal artery in 17 patients. Sixteen patients had inadequate saphenous veins for reversed vein grafts. The mean blood flow measured through these grafts (n = 20) was 164 +/- 22 ml/min and increased to 278 +/- 31 ml/min after administration of 30 mg of papaverine. All grafts were patent at the time of hospital discharge and patients were followed for 1 to 28 months. Life table analysis of the 30 procedures shows a patency of 100 percent at 18 months follow-up. One graft subsequently failed at 22 months. Long-term limb salvage was achieved in 100 percent of the patients in this series. The excellent blood flow through these grafts suggests that the in situ vein graft technique may be more favorable for arterial reconstruction than the reversed vein graft technique. Our preliminary data confirm the observations of Leather et al [3,4], that the rates of vein utilization and graft patency are higher with the in situ technique.

Adult↗
PubMed1983

Renal failure following abdominal aortic reconstruction.

Renal failure in aortic surgery is frequently due to the additive effects of multiple subthreshold insults that progressively decrease renal reserve. Prevention of renal failure requires a high index of suspicion concerning the clinical setting in which renal injury may occur. If cardiac hemodynamics and arterial pressure are maintained at optimal levels, especially during periods of maximum hemodynamic stress, ischemic renal injury can be minimized. This requires aggressive monitoring of cardiac hemodynamics using a Swan-Ganz (thermodilution) catheter for measurement of pulmonary artery wedge pressure and cardiac output. Prompt recognition of hemodynamic instability allows rapid intervention to correct the renal ischemia before irreversible renal injury can occur.

Acute Kidney Injury↗
PubMed1982

Lethal complications associated with nonrestrictive treatment of abdominal aortic aneurysms.

Five high-risk patients received nonresective treatment of abdominal aortic aneurysms (AAAs). This treatment included ligation of the iliac arteries to induce acute thrombosis of AAA and a simultaneous axillobifemoral bypass for restoration of arterial flow to the lower extremities. Of these five patients, lethal complications associated with this procedure developed in four. The complications included rupture, infection of the thrombotic aortic aneurysm, visceral ischemia, and consumptive coagulopathy. This high incidence of lethal complications and the unacceptably high patient mortality in these five patients indicates extreme precaution in the application of nonresective treatment for AAA.

Aged↗
PubMed1982

Bleeding esophageal varices: treatment with vasopressin, transhepatic embolization and selective splenorenal shunting.

The fate of 359 consecutive alcoholic cirrhotic male patients with bleeding esophageal varices was determined through chart review and personal interview. Three historical periods (1966-70; 1971-75; 1976-80) were defined based on availability of different therapeutic modalities. Management of acutely bleeding varices by conservative, nonsurgical means, including embolization, was preferable to emergency surgery when considering 30-day mortality rates. Percutaneous transhepatic embolization of esophagogastric varices significantly improved the rate of control of hemorrhage and 30-day survival over previously employed nonsurgical methods. The combination of nonsurgical management of acute variceal hemorrhage followed by selective distal splenorenal shunting resulted in maximum salvage of the alcoholic cirrhotic patient.

Embolization, Therapeutic↗
PubMed1981

Prevention of renal insufficiency after abdominal aortic aneurysm resection by optimal volume loading.

A retrospective case review of 34 men was undertaken to evaluate the relationship between preoperative volume loading and renal function before, during, and after abdominal aortic aneurysm surgery. Volume expansion was guided by either central venous pressure (CVP) in 12 patients or pulmonary artery wedge pressure (PAWP) measurements in 22 patients. Statistically significant differences (P less than .05) were noted between the two groups where greater preoperative volume loading and urine output were associated with lower postoperative serum creatinine and renal function indices in the PAWP group. The age range, vascular risk factors, aneurysm size, and preoperative renal function were similar. The data indicate that (1) PAWP is a more accurate monitor for volume expansion than CVP and (2) when volume replacement is optimal, abdominal aortic aneurysm surgery is not associated with postoperative renal insufficiency.

Acute Kidney Injury↗
PubMed1981

Bleeding esophageal varices: treatment by embolization and shunting.

An assessment was made of the treatment of 120 consecutive, alcoholic, cirrhotic patients with bleeding esophageal varices. Percutaneous, transhepatic embolization of the esophagaogastric varices resulted in control of the hemorrhage and this approach was more effective than were the non-surgical methods used. Management of acute variceal bleeding by conservative non-surgical means, including embolization, appears preferable to emergency portal-systemic shunts. The combination of non-surgical control of the acute variceal hemorrhage plus subsequent selective distal splenorenal shunting resulted in minimal encephalopathy and the most effective treatment.

Embolization, Therapeutic↗
PubMed1981

Computed tomographic angiography.

Computed tomographic angiography performed by the intravenous administration of contrast medium was evaluated in 86 vascular patients. This experience demonstrates a new approach to the evaluation of patients with symptomatic aortic aneurysms, in whom computed tomographic angiography will aid in evaluating the need for emergency surgery. Nonoperative patients are serially evaluated by computed tomographic angiography to detect significant changes in the geometric configuration of their aneurysms. Computed tomographic angiography was beneficial in the evaluation of the patency of vascular reconstructive procedures such as femoropopliteal bypass, aortoiliac bypass and application of a vena caval device. More clinical experience and possibly a rapid sequence technique are needed to evaluate patients with portasystemic shunts.

Abdomen↗
PubMed1981

Atherosclerotic aneurysms of the superficial femoral artery: a literature review and report of six additional cases.

Six patients with seven superficial femoral artery aneurysms are described, and additional cases in the literature are reviewed. Superficial femoral artery aneurysms are found in elderly patients with advanced atherosclerosis. These patients usually present with signs and symptoms of a high mass, often with local expansion and rupture. Proximal and distal ligation with vein bypass grafting was, for the authors, a satisfactory method of treatment. Patients with this lesion should be screened for possible abdominal aortic aneurysms, present in 33% of the authors' patients, and for other peripheral aneurysms, present in 50% of the authors' patients. Superficial femoral artery aneurysms should be surgically repaired, because when untreated, they tend to rupture and occasionally serve as a source of emboli.

Aged↗
PubMed1980

Volume loading and vasodilators in abdominal aortic aneurysmectomy.

Preoperative infusion of volume to increase the wedge pressure will maintain stable flow and arterial pressure at the time of aortic declamping. Usually 1,500 ml of balanced salt solution given with 75 g of albumin is sufficient to accomplish this purpose. Pressor or inotropic agents are not required. In our experience 14 percent of patients will have a down-slope in the preoperative myocardial performance curves. In these persons, volume infusions should be adjusted to keep the pulmonary arterial wedge pressure on the ascending portion of the curve. The use of vasodilator agents in normotensive patients has a deleterious effect on cardiac performance.

Aged↗
PubMed1978

Doppler ankle systolic blood pressure. Prognostic value in vein bypass grafts of the lower extremity.

The prognostic value of Doppler-derived ankle systolic pressure indices for predicting the patency of vein bypass grafts in the lower extremity was analyzed in 126 vein bypass grafts performed for limb salvage. Early or late graft failure was not found to correlate with the preoperative ankle systolic pressure index (ASPI). Intraoperative blood flow measurements did not correlate with the preoperative ASPI. An intraoperative graft flow of less than 0.7 at 24 to 48 hours, or an increase in ASPI of less than 0.4 were prognostic signs of early vein graft failure.

Adult↗
PubMed1978

Management of the upper extremity with absent pulses after cardiac catheterization.

Thirty-one patients had a delayed loss of brachial artery and radial artery pulse after cardiac catheterization; eleven of the patients had early embolectomy or a vein patch graft and 82% of these had immediate restoration of pulse and remained asymptomatic. Early surgery failed in two patients, requiring late vein bypass grafting for claudication. Twenty patients did not have early surgery, eleven (55%) remaining asymptomatic and nine (45%) developing ischemic symptoms. Five of these nine patients (25%) required late vein bypass grafting for severe claudication. Of the fifteen patients who lost their pulse and did not undergo surgery, the average Doppler forearm pressure immediately following the occlusion was 50 mm Hg (pressure index=0.46). The average Doppler pressure measured at the time of follow-up was 80 mm Hg (pressure index = 0.61). Early local surgery is highly successful in patients who lose their radial artery pulse after cardiac catheterization. Conservative nonoperative therapy may be successful but often results in late ischemic symptoms that may require late vein bypass grafting.

Arm↗