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Biomedical subjects

G M Baur

Publications and source records attributed to G M Baur.

At least 19 recordsLinked to original sources
PubMed1984

Intraarterial streptokinase infusion for acute popliteal and tibial artery occlusion.

Eight consecutive patients with acute thrombotic or embolic occlusion of the popliteal or tibial artery were treated with low-dose intraarterial streptokinase followed by arterial reconstructive surgery where appropriate. Three patients had acute thrombosis of a popliteal aneurysm with limb-threatening ischemia. All three were relieved of their acute ischemia by streptokinase infusion accompanied by lysis of clots in the popliteal artery outflow tract. Each patient then underwent elective popliteal aneurysm bypass. Four patients had acute embolic popliteal or tibial artery occlusion. Each was relieved of ischemic symptoms. One required surgery to remove residual clot. One patient with thrombosis of the tibioperoneal trunk did not have a decrease in symptoms with streptokinase infusion, but did experience sufficient outflow tract thrombolysis to permit construction of a tibial bypass with resultant restoration of normal circulation. Low-dose intraarterial streptokinase may be the treatment of choice for selected patients who present with thrombosis of a popliteal aneurysm with tibial vessel involvement or with embolic popliteal or tibial artery occlusion.

Acute Disease↗
PubMed1984

Treatment of chronic visceral ischemia.

Herein, we have described the surgical management of 23 patients with chronic intestinal ischemia. The patients presented most commonly with postprandial pain and weight loss. Diagnosis was confirmed by angiography, including lateral aortography. Surgery included bypass with Dacron being the most common graft material. As many vessels as possible were revascularized using an infrarenal graft origin. Two patients died postoperatively from acute myocardial infarction. There were two graft failures in this group. At the present time, 19 of the 21 surviving patients are asymptomatic or greatly improved.

Adult↗
PubMed1983

Extracellular volume expansion and delayed resolution of hypertension after canine aortic coarctectomy.

The hemodynamic changes occurring after surgical correction of thoracic aortic coarctation were studied in two neonatally coarcted dogs at six months of age and compared to sham surgery in two littermate controls. Excision of the tight iatrogenic aortic band with direct aortic reanastomosis abolished pressure gradients. Post-coarctectomy systemic pressure rose, after an early transient fall, to pre-operative proximal levels and was sustained for two to four weeks before decreasing to control normotensive values. Femoral systolic pressure (and renal perfusion pressure) rose by 47-57 mmHg in coarcted dogs (p less than .001). Extracellular volume (ECV) increased in both coarcted animals, peaking 28-32 cc/kg (7.1-7.6% increase) above precoarctectomy levels. Peak ECV expansion coincided with the peak post-coarctectomy blood pressure. Fluid administration, blood losses and plasma renin activity (PRA) were comparable in all animals. Post-coarctectomy tachycardia was also noted in coarcted dogs (p less than .001), whereas neither ECV nor heart rate changes occurred in control animals. We postulate that post-coarctectomy baroreceptor stimulation results in sympathetically-mediated renal sodium retention, not only preventing a pressure diuresis, but resulting in overt volume expansion. Failure of PRA suppression despite increased distal pressure and volume excess may also reflect sympathetic activation. Data are compatible with the view that sympathetic activation and consequent volume expansion transiently sustain hypertension in the post-coarctectomy setting until baroreceptor re-adjustments permit normalization of blood pressure.

Animals↗
PubMed1983

Blood flow in the common femoral artery. Evaluation in a vascular laboratory.

Accurate knowledge of the hemodynamics of the common femoral artery is a critical part of both the preoperative evaluation of patients with peripheral vascular disease and the postoperative follow-up examination. Interrogation of the iliofemoral system with determinations of palpable pulse status, Doppler analog waveforms, and upper thigh pressure ratios has yielded an overall sensitivity of 91 percent and a specificity of 85 percent in the detection of inflow stenosis. This degree of accuracy (89 percent) allows practical surgical decisions to be based on the results of these noninvasive studies.

Aged↗
PubMed1982

Arm ischemia secondary to giant cell arteritis.

Six cases of arterial insufficiency of the arm secondary to giant cell arteritis are described, all in elderly white women. The clinical presentation of the occlusive disease ranged from an asymptomatic incidental physical finding to an alarming picture of severe ischemia. All patients were treated with steroids and had subsequent stabilization or improvement of extremity symptoms. Vascular reconstruction was also performed in two patients, one of whom developed rest pain after graft occlusion. Another patient had a cerebral infarction while taking prednisone, despite control of large vessel vasculitis. This study indicates that giant cell arteritis should be considered in cases of occlusive disease of the arms, especially in elderly women. Giant cell arteritis is a seriously morbid and potentially fatal disease which justifies a thorough evaluation when sufficient evidence is present to suggest the diagnosis. The response to steroids is usually adequate to eliminate the need for early surgical intervention.

Aged↗
PubMed1982

Treatment of finger ischemia with Bier block reserpine.

Fourteen patients with severe Raynaud symptoms, including four patients with ulceration of the fingers, were treated by regional medical sympathectomy achieved by the tourniquet controlled intravenous injection of reserpine. Nine of the patients had significant objective clinical improvement which, in each patient, correlated with the demonstration of vasospasm on pretreatment studies. The five patients without improvement had advanced organic obstructive arterial disease without vasospasm.

Adult↗
PubMed1981

Lower-extremity amputations for ischemia.

During the past eight years, we performed 312 lower-extremity amputations for ischemia. Amputation requiring no prosthesis was achieved in 31% of patients, knee joint preservation in 72%, and overall primary amputation healing in 75%. Amputation mortality was 6%. The use of prior arterial reconstruction, careful wound care, and willingness to accept nonhealing of trial amputations were important factors in obtaining the most distal possible healed amputation. An accurate evaluation of the impact of new methods of selecting amputation level and evaluating amputation results can only be achieved by a report of the total institutional amputation experience, not by reports of a single type of amputation.

Aged↗
PubMed1981

Precise diagnosis of aortic anastomotic aneurysm by computed tomographic scan.

False aneurysms that involve aortoprosthetic anastomoses may be difficult to diagnose prior to fatal rupture. We report a case in which a false aneurysm that developed six year after aortofemoral-graft insertion was accurately diagnosed by a computed tomographic (CT) scan after both ultrasonography and angiography had failed to make the diagnosis. The ability of CT scanning to demonstrate anastomotic aneurysms and accurately determine the presence of periaortic hemorrhage is discussed.

Aged↗
PubMed1981

Extended profundaplasty. Indications and techniques with results of 46 procedures.

We performed extended profundaplasty 46 times in 36 patients. Twelve procedures were performed for ischemic ulcers, 23 for ischemic rest pain and 10 for short-distance claudication. Fourteen procedures were performed independently, 21 to provide outflow for proximal bypass grafts, and 11 were combined with distal bypass grafts. Four of the 46 procedures failed; the rest have been successful for limb salvage or relief of symptoms at a mean follow-up of 15 months. Technical points emphasized are autogenous patch closure of the entire endarterectomy site and careful attention to end-point detail. The results demonstrate that this procedure provides durable limb revascularization.

Aged↗
PubMed1981

Evaluation and management of patients with Raynaud's syndrome.

The wide spectrum of associated disorders, the previous lack of understanding of pathogenesis, and the older, arbitrary terminology in relation to ultimate prognosis have led to confusion in the evaluation and management of Raynaud's syndrome. A unified concept of pathogenesis, in which vasospasm and arterial occlusive disease are the fundamental lesions, is presented herein. The associated disorders found in our 219 patients with continuous follow-up are listed and related to the underlying pathogenetic mechanisms. Our approach to diagnosis led to the discovery of an associated condition in 71 percent of our patients. The evaluation can be done in a cost-effective manner. The emphasis of treatment should be on conservative medical management, with avoidance of cold and tobacco and judicious use of pharmacologic agents remaining the cornerstones of therapy. Cervicothoracic sympathectomy has no role in the treatment of Raynaud's syndrome.

Adult↗
PubMed1981

Percutaneous angiographic embolization: a procedure of increasing usefulness: review of a decade of experience.

During the past decade percutaneous therapeutic vascular occlusion was performed on 152 occasions in 124 patients. The primary indication for vasoocclusive therapy was acute or recurrent bleeding. Upper gastrointestinal bleeding from arterial sources was controlled in 92 percent of patients and acute variceal bleeding in 83 percent. Renal embolization was performed for palliation of severe pain and hematuria from unresectable renal primary or secondary malignancies, to decrease blood loss and facilitate surgery in operable renal tumors, and for ablation of renal function to control chronic protein loss or severe hypertension. Our encouraging experience convinces us that transcatheter embolization is a useful, safe and effective procedure in selected patients. It seems certain that the technique of therapeutic embolization will be improved, its indications extended and its application become commonplace whenever angiographic skills and facilities exist.

Angiography↗
PubMed1981

Finger gangrene caused by small artery occlusive disease.

Available evidence indicates that about one third of all patients presenting with localized finger gangrene developed the condition due to intrinsic occlusions of the small arteries of the hand and fingers caused by one of a variety of systemic diseases. We have treated 35 such patients in the past seven years. A variety of diagnostic tests allowed the establishment of the diagnosis of connective tissue disease in 14 patients, hypersensitivity angiitis in 13 patients, arteriosclerosis in five patients, and myeloid metaplasia, calciphylaxis, and carcinoma in one patient each. Treatment with cold and tobacco avoidance, vasodilators, and local debridement produced good results without amputation in 30 patients. Five patients required partial phalangeal amputation. These results suggest that appropriate diagnostic tests will allow an accurate diagnosis in all patients, and that the natural history is that of spontaneous improvement without major tissue loss. In our experience, surgical sympathectomy plays no role in the treatment of these patients.

Adolescent↗
PubMed1979

Human umbilical cord vein allograft arteriovenous fistula for chemotherapy access.

Seven patients who received chronic chemotherapy and required vascular access underwent construction of an arteriovenous fistula of the leg using gluteraldehyde-tanned human umbilical cord vein allografts. No wound or graft complications have occurred and patient tolerance of the operative procedure and subsequent use of the fisulas for chemotherapy has been excellent. Our preliminary results suggest that the use of umbilical vein allograft arteriovenous fistulas is quite satisfactory for long-term chemotherapy access.

Adult↗
PubMed1979

Antigenicity of venous allografts.

With isolated exceptions, the clinical use of venous allografts has been disappointing. Considerable evidence indicates that allograft antigenicity plays a major role in the failure of venous allografts when used as arterial replacements. Recent reports suggest that DMSO-cryopreservation of venous allografts may reduce allograft antigenicity while preserving allograft viability. The present study examines the effect of modifications of vein allografts on subsequent allograft antigenicity. Skin grafts were transplanted from ACI to Lewis inbred strains of male rats. Primary skin graft rejection occurred in 9.0 +/- 1.0 days. Subcutaneous implantation of fresh inferior vena cava from ACI rate into Lewis rats resulted in subsequent skin graft rejection in 5.0 +/- 1.0 days, confirming the antigenicity of venous tissue. Cryopreservation of ACI inferior vena cava for seven days prior to implantation, with or without 15% DMSO, resulted in subsequent skin graft rejection in 5.0 +/- 1.0 days. Treatment of ACI inferior vena cava with 0.30% gluteraldehyde for 20 minutes prior to implantation in Lewis rats resulted in skin graft rejection in 9.0 +/- 1.0 days, the same time as a first set rejection. This study indicates that unmodified veins are normally antigenic and that this antigenicity is not eliminated by cryopreservation with or without DMSO. Gluteraldehyde treatment appears to reduce allograft antigenicity, but results in a nonviable graft. At the present time, there is no known way to reduce the antigenicity of viable venous allografts.

Animals↗
PubMed1978

Value of angiography in the management of abdominal aortic aneurysm.

The value of angiography in the management of abdominal aortic aneurysms (AAA) was assessed in 100 consecutive patients with AAA. Angiographic information influenced management decisons and/or surgery performance in 75: In 23 patients at high risk for surgery because of associated medical problems, it helped in deferring surgery; in 52 patients it resulted in a change of operation from a standard aneurysm resection with conventional grafting to a more conservative procedure (three patients), more extensive grafting (45 patients) and/or the addition of other vascular reconstructions (32 patients). Angiography is considered an integral step in the routine preoperative workup of AAA and is particularly valuable for the determination of important anatomic details about the aneurysm (upper and lower extensions, relation to the renal arteries), the detection of associated vascular disease (of renal, visceral, pelvic and peripheral arteries), and the demonstration of aberrant renal arteries and collateral visceral circulation. Catheter techniques are considered most suitable and safe for examination of AAA.

Aged↗
PubMed1978

The role of arteriography in abdominal aortic aneurysm.

The results of arteriography in the management of 100 consecutive patients with abdominal aortic aneurysms are presented. Arteriographic information had substantial influence upon management decisions and performance of surgery in 75 per cent of cases. We found the preoperative knowledge of the precise vascular pathology or anatomic variants not only permitted a more rational recommendation for or against surgery but aided in the selection of the most suitable surgical procedure.

Aged↗
PubMed1978

Lower extremity amputation for ischemia.

Three hundred-twenty-four amputations of the lower extremity for ischemia at the University of Oregon Health Sciences Center over the past ten years are presented. Striking differences between the first and second five-year periods are noted in level of amputation. The primary healing rate of all patients in the two periods was similar. Diabetics tended to have more distal amputations but primary healing was lower than that of nondiabetics.

Amputation, Surgical↗