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Biomedical subjects

R H Clauss

Publications and source records attributed to R H Clauss.

At least 37 records · Page 2Linked to original sources
PubMed1983

Expanded microporous polytetrafluoroethylene (PTFE) grafts in contaminated wounds: experimental and clinical study.

Autogenous vein graft is regarded as an ideal arterial substitute for its long-term patency and relative resistance to infection. A clinical instance of life-threatening hemorrhage from an infected disrupted vein graft stimulated a study in dogs, comparing vein and PTFE graft performance in wounds contaminated with S. aureus and E. coli cultured from the patient's wound. Infective disruption of vein wall occurred in three of ten animals resulting in exsanguination and death. Host artery disruption at PTFE suture line occurred in one of ten animals. Thrombosis of graft and host artery in this animal precluded hemorrhage and death. This led to favorable clinical experiences with PTFE grafts in contaminated wounds of 22 trauma patients. It is concluded that PTFE is better assurance against disruption and hemorrhage than vein graft in contaminated, potentially infected sites. PTFE may be used preferentially as a vascular substitute in trauma patients provided that all traditional surgical safeguards and principles are followed.

Adult↗
PubMed1982

Unappreciated causes of ischemia in the leg.

Limb ischemia due to blunt trauma, dissecting hematoma, and cardiac dysfunction jeopardizes limbs and lives more than is generally appreciated. Delay in diagnosis after blunt trauma led to major amputation in 21 percent of our patients. Current principles avoid those hazards. Five patients presented with acute limb ischemia caused by dissecting hematoma of the aorta. Suspicion of that diagnosis is warranted in patients without a history of chronic vascular occlusive disease or cardiac disease, in young white males with Marfan characteristics, and in middle-aged hypertensive black males. Confirmation of the diagnosis requires urgent angiography. In selected cases, treatment with femorofemoral bypass will be limb- and life-saving. Ischemia due to low flow, which portends a dire prognosis, should be suspected in severely ill patients with a history of peripheral vascular disease. Analysis of cardiac and metabolic functions with the Automated Physiologic Profile system identified the cause of the low flow state in 10 patients, permitting precise management with specific therapy. A discernible improvement in circulatory status of the limb coincided with correction of the low flow states. Angiography and surgery were not necessary in 90 percent of this group, and should be avoided during low flow episodes.

Aortic Aneurysm↗
PubMed1982

Experience with 115 civilian venous injuries.

Retrospective analysis of 115 patients with venous injuries managed at Lincoln Hospital in a 7-year period disclosed a total mortality of 15%. Retrohepatic caval injury was uniformly fatal; infrarenal caval injury was not. Fifty-six per cent of victims of truncal venoarterial injuries died. Isolated venous injury of the extremity was never lethal. Ligation of injured veins of the neck and upper extremities was well tolerated. Ligation of external iliac, or common femoral, or superficial femoral veins resulted in edema in 50% of the patients compared to 7% after repair (p less than 0.05). Venoarterial injuries of iliac or femoral-level veins resulted in 37% incidence of compartment syndrome against 5% in isolated arterial injuries (p less than 0.01). Therapeutic fasciotomy after the onset of clinically evident compartment syndrome did not prevent foot drop in any patient. We advocate that all major veins of the lower extremities be repaired with the same care as arterial injuries. Prophylactic fasciotomy for all patients with iliac or femoral venoarterial injuries should be considered as strongly as with popliteal venoarterial injuries. The caliber and patency of repaired veins must be assessed by venography at operation, and again before discharge from the hospital.

Adolescent↗
PubMed1981

Manual coronary endarterectomy with saphenous bypass: experience with 263 patients.

From January, 1972, until August, 1980, 271 manual coronary endarterectomies with bypass were performed in 263 patients. All patients underwent additional cardiac procedures simultaneously. The group contained 254 distal right and 17 left endarterectomies (including 8 double endarterectomies). Clinical follow-up was 100%, operative mortality was 2.3% (6 out of 263), and the rate of perioperative infarction was 4.9% (13 out of 263). Cineangiography was performed on 72 patients between 1 and 60 months after operation (mean, 15.4 months). Patency was 85% (61 out of 72). Endarterectomy in a dominant right coronary artery could be planned electively. Left coronary endarterectomy was performed only when diffuse disease prevented standard bypass. Coronary endarterectomy may be used to extend operability with excellent clinical results, low perioperative mortality, and high late patency. Careful attention to technical aspects of core removal and myocardial protection are necessary for consistent results.

Adult↗
PubMed1981

Automated physiological profile assessment of effects of altered cardiovascular dynamics on brain blood flow.

Brain blood flow may be compromised as severely by altered cardiovascular dynamics as by atherosclerotic flow-limiting lesions in carotid arteries. The Automated Physiologic Profile can distinguish between those clinically important mechanisms. The Automated Physiologic Profile is a concept and method and apparatus. Physiologic performance of the heart, vascular tone in systemic and pulmonary vessels, and oxygen consumption are derived and printed on a standard report form. This easy to use form identifies mechanisms and illustrates severity of patho-physiologic aberrations contributing to ischemia-inducing processes. Serial portrayal depicts effectiveness of therapeutic interventions. This report included examples of APP in patients with ventricular rhythm disturbance, sick sinus syndrome, hypovolemic low cardiac out-put, and carotid artery stenosis as contributing factors in clinical cerebrovascular insufficiency. All were accompanied by excessive systemic arteriolar resistance, implying reduced brain blood flow. Serial APPs correlated with clinical events in the case histories.

Aged↗
PubMed1980

Monitor-guided responses. Operability with safety is increased in patients with peripheral vascular diseases.

Poor cardiopulmonary reserve was demonstrated in a group of 75 elderly patients undergoing elective vascular reconstruction when cardiovascular hemodynamics were analyzed with the automated physiologic profile (APP) preoperatively. Only 25 patients (33.3%) had normal left ventricular function (LVF) and did not need any corrective therapy before surgery. Increment in preload was necessary in 20 patients (26.7%) to improve myocardial function; 30 patients (40%) revealed abnormal LVF and hence required pharmacologic modulation and preload adjustment, inotropic support, and afterload reduction to enhance the ventricular performance. Conventional methods of clinical evaluation did not reveal the degree of compromised ventricular function and potential high risk of surgical morbidity and mortality in many of these patients. The APP disclosed subtle and important physiologic aberrations indicating modification of anesthetic and operative procedures and precise modulation of physiologic factors. Optimization was achieved in all except two patients, and only one was denied the benefits of vascular reconstruction.

Aged↗
PubMed1980

Transluminal coronary angioplasty during saphenous coronary bypass surgery: a preliminary report.

A previously described balloon tipped dilatation catheter has been used during revascularization surgery to dilate lesions which potentially could limit the runoff of the saphenous bypass grafts. A total of 34 lesions were dilated in 25 patients. Restudy of 12 patients (15 lesions) demonstrated positive results and no clinically significant complications. These preliminary results suggest an important role for transluminal coronary dilatation in the operative treatment of coronary artery disease.

Aged↗
PubMed1980

Pathological fibrinolysis secondary to pseudoaneurysms.

Pathological fibrinolysis due to pseudoaneurysms was observed in a patient 4 years after aortobifemoral bypass graft. The patient presented with a pulsatile abdominal mass and ischemic changes in the legs. Excessive bleeding from venipuncture sites prompted coagulation screening, which disclosed rapid clot lysis, fibrin split products, and low fibrinogen suggestive of pathological fibrinolysis. Therapy with epsilon amino caproic acid (EACA, Amicar) controlled the coagulopathy, permitting angiography and operation. Resection of the pseudoaneurysms resulted in resolution of the abnormal fibrinolysis. Normally, there is a balance between coagulation and fibrinolysis protecting against excessive bleeding or clotting. Clot itself is a powerful stimulus for the activation of the fibrinolytic system, although many other factors have been shown to initiate and sustain the process. Fibrinolysis is pathological when the process becomes excessive or inappropriate. Plasminogen is activated to plasmin which digests fibrin. Both plasmin and fibrin split products inhibit polymerization of fibrin monomers (which is the final step in the coagulation cascade in the formation of a stable clot), resulting in an unstable clot which is rapidly lysed. To our knowledge such a coagulopathy has not been reported to be a complication of pseudoaneurysms.

Aminocaproic Acid↗
PubMed1979

Massive hyperplastic thymus in a 22-month-old infant.

Huge mediastinal masses in infants are often difficult to diagnose, and thymic enlargement must be considered in each instance, especially when the mass is located anteriorly. In the patient reported on here, the mass occupied approximately 60% of the chest cavity, and surgical intervention was required to establish the precise histological diagnosis. This proved to be massive hyperplastic thymus.

Female↗
PubMed1978

Planned extra-anatomic cerebral revascularization for carotid artery ligation.

Cerebral revascularization, using extra-anatomic bypass grafts of autologous saphenous vein, was performed in three patients to prevent or to compensate for ischemic effects of emergency ligation of a carotid artery. These ligations were required after spontaneous disruption of common carotid arteries in patients with previous irradiation and radical head and neck surgery. External-carotid-to-external-carotid cross-over (submandibular) bypass graft was performed once, and ipsilateral axillointernal carotid bypass grafts twice. The role of infection in carotid artery rupture, the unpredictable nature and different mechanisms of cerebral malfunctions after carotid ligation, technical details of extra-anatomic bypass grafts, and anatomic considerations in the prevention of recurrent infection and bleeding are discussed. A planned approach of cerebral revascularization at the time of ligation appears to be preferable to a fortuitous outcome. Neurological disability and death from cerebral ischemia can be prevented by using extraanatomic bypass vein grafts.

Brain↗
PubMed1976

Aortic insufficiency. A result of intermittent migration of aortic valve prosthesis poppet.

A bizarre mechanism of aortic valve incompetence was observed when the occluder of a Braunwald-Cutter aortic valve prosthesis decreased in diameter, volume, and weight, and from time to time fell into the left ventricle. The patient's symptoms were palpitation, coughing, chocking sensations, and fright. An operation disclosed a small, smooth ball with disrupted cloth on all the struts. The residual torn mesh was removed, and the ball was replaced.

Aorta↗
PubMed1976

Simultaneous bilateral carotid endarterectomies.

Twelve patients with bilateral symptomatic lesions of internal carotid arteries have had bilateral carotid endarterectomy at single operations without complications. These were patients up to age 80 who had prior mycardial infarction, stroke with recovery, and hemispheric and nonhemispheric episodes. Neurologist's clearance and three- or four-vessel intracranial-extracranial angiography preceded all operations, which were performed with the patient under general anesthesia. Stump pressure measurements were the principal guideline of adequacy of collateral flow and predictor of safe outcome. The safety of this concept of bilateral operations during one anesthesia can eliminate uncertainties of sequence and timing, obviate delay and indecision, and avoid the hazards of a second anesthetic-operative experience.

Aged↗
PubMed1976

Civilian arterial injuries.

During 1968-1973, 122 patients with 126 arterial injuries were treated. In 94 instances (90 patients), these injuries involved extremities. Systolic blood pressure was below 90 mm Hg upon admission in 55.6% of all patients and 37.7% of those with injuries to arteries of the extremities. The decision for operative exploration and repair of arteries of extremities was based largely on clinical grounds (shock, loss of pulse). Preoperative arteriography was needed infrequently, while operative angiography was nearly routine. Although several cases of late revascularization or traumatic thrombosis of renal artery have been reported, hypertension complicates the postoperative period, and early, aggressive approach is essential. Mortality was 10.6%, from aortic injuries. There were no deaths among patients with arterial injuries distal to inguinal ligament or thoracic outlet. The amputation rate from reconstruction failure was 1.1%, none occurring in the last 3 years of the series. The high patency rate and lack of evidence of pulmonary embolization suggest that associated venous injuries be repaired routinely. Arterial injuries represent ideal lesions (normal arterial wall with excellent run-in and run-off). Prompt treatment of shock and early, proper management of patients' mechanical disruptions will salvage many lives and most limbs.

Adolescent↗
PubMed1976

Traumatic pseudoaneurysms: a review of 32 cases.

The management of 23 patients with traumatic pseudoaneurysms is presented. A pulsatile mass associated with pain was the usual presentation. Hypertension and hypovolemic shock from rupture are uncommon presentations but potential hazards of this lesion. Twenty-one pseudoaaeurysms were treated surgically. Resection with end-to-end anastomosis (eight patients), with graft replacement (one patient), with lateral repair (seven patients) was done. Hypothermia with circulatory arrest and external Dacron shunt were used to prevent visceral ischemia during high aortic occlusion. There were no mortalities or significant postoperative complications.

Adolescent↗
PubMed1975

Progression of occlusive atherosclerosis. Long-term administration of pyridinol carbamate.

The effects of pyridinol carbamate, a drug with demonstrated capacity to inhibit development of atherosclerotic plaques in the rabbit, were studied in humans with symptoms of arterial occlusive disease in the lower extremities. Microcirculation, perfusion, claudication distance, peripheral pulsations, and angiographic appearances were supplemented by clinical impressions over a two-year period. Although the drug was discontinued in several patients from a larger group because of gastrointestinal tract symptoms, and for other reasons, seven of eight patients receiving it showed no progression of their disease, whereas all 15 patients receiving identical-appearing placebos did. Although the number of patients is not sufficient to warrant statistical conclusions, the observations were totally objective and strongly encourage further control of studies.

Age Factors↗