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Biomedical subjects

S M Lindenauer

Publications and source records attributed to S M Lindenauer.

At least 55 records · Page 3Linked to original sources
PubMed1980

Splanchnic arteriosclerotic disease and intestinal angina.

Twenty-three patients (13 women and ten men, 33 to 73 years old) underwent reconstruction of 33 major splanchnic arteries for relief of symptomatic intestinal ischemia. All patients experienced postprandial abdominal pain and lost weight (average, 12.8 kg). Arterial reconstructions (32 bypass procedures and one endarterectomy with patch-graft arterioplasty) were undertaken with both autogenous saphenous vein (24) and prosthetic condults (nine). Revascularizations involved the superior mesenteric (21), celiac (five), hepatic (four), splenic (two), and inferior mesenteric (one) arteries. There were four postoperative deaths; three occurred after emergent secondary attempts at intestinal revascularization. All of the 19 patients who survived benefited from operative intervention.

Abdomen↗
PubMed1980

Clinical significance of arteriosclerotic femoral artery aneurysms.

One hundred seventy-two arteriosclerotic femoral artery aneurysms in 100 male patients, 47 to 91 years old, were evaluated. They were bilateral in 72% of the patients, and were associated with aortoiliac aneurysmal disease in 85% and with popilteal artery aneurysms in 44%. Femoral artery aneurysms were asymptomatic in 40 patients. Thirteen patients with thromboembolic episodes and two with rupture had ischemic limbs. Thirty-eight patients underwent primary operation for 50 femoral aneurysms, including 36 lower extremity arterial reconstructions, ten aortofemoral bypasses, one arterial ligation, and three amputations. Two operative deaths occurred, both associated with concomitant aortic surgery. Only three of 105 aneurysms in 58 patients followed nonoperatively were associated with later major limb-threatening complications. The low complication rate attending small, bland aneurysms justified nonoperative management. Large or symptomatic aneurysms warrant early operative intervention.

Aged↗
PubMed1980

Gastroduodenal and pancreaticoduodenal artery aneurysms: a complication of pancreatitis causing spontaneous gastrointestinal hemorrhage.

Aneurysmal degeneration of gastroduodenal and pancreaticoduodenal arteries due to acute and chronic forms of pancreatitis is uncommon. Gastrointestinal hemorrhage secondary to these vascular lesions has been recognized in only 23 patients. Eight of these patients, including five with gastroduodenal and three with pancreaticoduodenal artery aneurysms, have been encountered at the University of Michigan Medical Center. Selective mesenteric arteriography provided the greatest diagnostic specificity. Computerized axial tomography was of discriminate diagnostic value in two patients. Seven of eight patients underwent surgical therapy: transcystic arterial ligation and external pancreatic pseudocyst drainage (four), arterial ligation with abscess drainage (two), and pancreaticoduodenectomy (one). Three patients died after operation from intraabdominal sepsis as well as delayed arterial hemorrhage. Earlier operative intervention, dictated by the patient's clinical status and relevant anatomic findings, may improve survival rates in this complex disease state.

Adult↗
PubMed1980

Hemodynamic effects of sympathectomy in ischemic canine hindlimbs.

One week after unilateral distal superficial femoral artery ligation, 15 anesthetized dogs were studied before and after bilateral lumbar sympathectomy. Total hindlimb capillary (THC) flow and arteriovenous anastomotic (AVA) flow were determined by microsphere arteriovenous (A-V) shunt measurement combined with electromagnetic femoral artery blood flow measurement. Muscle capillary blood flow (MBF) was measured by xenon133 clearance. Baseline femoral blood flow in ischemic (I) hindlimbs was only 53% of contralateral control (C) hindlimbs (I = 56, C = 105 ml/min, P less than 0.01). Ischemia was manifest in I limbs by reduced O2 consumption (I = 1.68, C = 2.53 ml of O2/min, P less than 0.01). After sympathectomy, total blood flow increased significantly in I limbs, but no improvement in O2 consumption occurred. This was due to increased A-V shunting, with increased AVA flow (from 3 to 20 ml/min. P less than 0.01) but unchanged THC flow. Neither resting nor reactive hyperemic MBF improved after sympathectomy. Control limbs showed similarly increased AVA flow, but decreased O2 consumption, suggesting a detrimental effect of sympathectomy. The major hemodynamic consequence of sympathectomy in ischemic canine hindlimbs was increased nonnutritive A-V shunting, with no improvement in total capillary flow.

Animals↗
PubMed1979

Pelvic exenteration for advanced rectal carcinoma.

Twelve patients with advanced rectal cancer and no evidence of extrapelvic metastases underwent pelvic exenteration. The operative mortality rate was 8.3 per cent. Determinate 3 and 5 year survival rates of 54 and 37 per cent were achieved. Criteria for the selection of patients and techniques of supravesical urinary diversion are discussed.

Aged↗
PubMed1979

Direct measurement of arteriovenous anastomotic blood flow in the septic canine hindlimb.

Absolute blood flow through hindlimb capillaries and arteriovenous anastomoses (AVA) was determined by the radioactive microsphere technique of relative shunt measurement combined with direct (electromagnetic) measurement of femoral artery blood flow. Studies were performed before and 72 hours after infection was created in six dogs by implanting fecal-contaminated wicks in one hindlimb. Three control dogs had sterile wicks implanted. Septic dogs demonstrated decreased arterial pressure and increased core temperature with no change in mean cardiac index. Infected legs had increased total femoral blood flow, decreased peripheral resistance, decreased arteriovenous (A-V) O2 difference, but unchanged oxygen consumption, Paw temperature increased in both infected and normal contralateral limbs. Muscle blood flow (MBF) (Xe133 clearance) increased only in infected legs. A-V shunting increased five-fold and AVA flow increased seven-fold in infected hindlimbs, significantly more than that in contralateral or control limbs. Increased A-V shunting correlated highly (r=0.95) with increased total femoral blood flow in infected legs, but increased MBF was not correlated (r=0.05). Despite increased MBF, increased AVA flow occurs in septic canine hindlimbs and contributes to the low-resistance, high-flow, but unchanged oxygen consumption described in this model.

Animals↗
PubMed1979

Abdominal aortic coarctation and segmental hypoplasia.

Functionally significant, nonatherosclerotic, noninflammatory, concentric and tubular stenoses of the abdominal aorta, 4 to 16 cm in length, were encountered in five male and five female patients 11 to 49 years old. Seven patients were younger than 19 years of age. Aortic branch stenoses were common, affecting splanchnic vessels in seven patients and renal arteries in eight patients. The pathogenesis of the aortic constrictive lesions remains unknown, but it may be related to developmental error or aortic growth arrest. Existence of multiple renal arteries in 70% of these patients lends support to the developmental hypothesis. Intimal fibroplasia characterized stenotic aortic tissue. Severe hypertension was common, with the mean preoperative arterial pressure being 200/119 mm Hg. Thoracoabdominal bypass was undertaken in eight patients, being combined with renovascular reconstruction on five occasions. Two patients underwent patch graft aortoplasty with bilateral renal revascularization. Therapeutic results were classified as excellent six times and as good four times. Single-stage arterial reconstructions are the preferred method of treatment for abdominal aortic coarctation or segmental hypoplasia with associated aortic branch disease.

Adolescent↗
PubMed1979

Pancreatic abscess.

Compared with the general hospital population of patients with pancreatitis, patients with biliary tract or peptic ulcer disease have de novo pancreatic abscesses develop more commonly than patients with alcoholic pancreatitis. The apparent greater predisposition of the patient with biliary tract or peptic ulcer disease to infection does not seem to be due so much to these patients having potential sources of infection, such as an infected biliary tract or leaking ulcer, as to the fact that many patients with alcoholism and hemorrhagic pancreatitis never survive the fluid loss phase of pancreatitis long enough to have a secondary infection and abscess. The mortality associated with the development of de novo pancreatic abscesses is higher in patients with biliary disease, peptic ulcer or idiopathic pancreatitis in comparison with those patients with alcoholic pancreatitis. Some complications of pancreatic abscesses, such as renal failure, may be avoided through appropriate management of fluid losses during the hemorrhagic phase of pancreatitis preceding absecess formation. Good medical management and aggressive use of newer diagnostic and therapeutic modalities may reduce the mortality and complications of pancreatic abscess. Prompt drainage of an abscess once identified is essential to survival. Proximal colostomy or ileostomy is indicated in the patient with a colonic fistula. Large particulate chunks of necrotic pancreas are not easily evacuated through Penrose, cigarette or sump drains. Marsupialization of the abscess may be considered in patients with this type of abscess.

Abscess↗
PubMed1977

Femoropopliteal bypass for limb salvage.

A total of 148 femoropopliteal bypass procedures followed for a minimum of 2 years yielded a patency rate of 61.9 percent among survivors. Diabetes mellitus, cigarette smoking, quality of the outflow, or prior inflow procedures did not influence patency rate. Results were less satisfactory in women and when cloth grafts were used. The indications for femoropopliteal bypass require continuing careful assessment.

Adult↗
PubMed1977

Direct measurement of arteriovenous anastomotic blood flow after lumbar sympathectomy.

Absolute blood flows through hind limb capillaries and arteriovenous anastomoses (AVA) were determined by the radioactive microsphere technique of relative shunt measurement combined with direct (electromagnetic) measurement of femoral artery flow. Hemodynamic parameters were measured before and after laparotomy, after unilateral lumbar sympathectomy, during reactive hyperemia, and during alpha adrenergic blockade in normal and sympathectomized hindlimbs of six anesthetized dogs. After sympathectomy arteriovenous (A-V) shunting increased from 3.8 to 32.1% (p less than 0.05). AVA flow increased from 4 to 54 ml/minute (p less than 0.01), while capillary flow was unchanged. Nonsympathectomized limbs did not demonstrate these changes. During reactive hyperemia, capillary flow increased more than 100% (p less than 0.03) in both normal and sympathectomized limbs, while AVA flow was unchanged. After phentolamine (5 mg, intravenously), AVA flow increased from 2 to 19 ml/minute (p less than 0.01) only in nonsympathectomized limbs. Phentolamine mimicked surgical sympathectomy effects in nonsympathectomized limbs, with paw temperature, femoral flow, A-V O2 difference, A-V shunting, AVA flow, and capillary flow equal to sympathectomized limbs after phentolamine administration. In the acute canine model, increased blood flow after sympathectomy is due to increased nonnutritive AVA flow, with no change in total hindlimb capillary flow, both at rest and during reactive hyperemia.

Animals↗
PubMed1976

The influence of venous occlusion on xenon 133 muscle clearance.

Progressive degrees of venous occlusion in the canine hind limb were employed to evaluate the influence of venous disease on the xenon 133 muscle washout test. Increasing degrees of venous occlusion, from superficial venous occlusion alone to total occlusion induced with intravenously administered thrombin, decreased both resting muscle blood flow and maximal muscle blood flow stimulated with intra-arterially administered papaverine hydrochloride. This alteration lasted for varying lengths of time with all but the group with total venous occlusion eventually returning to a normal flow. The status of the venous circulation must be considered in order to accurately interpret the results of the 133Xe clearance test when used to evaluate arterial occlusive disease. The 133Xe washout test may be an accurate indicator of venous occlusion in a limb with normal arterial supply.

Animals↗