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Biomedical subjects

R H Clauss

Publications and source records attributed to R H Clauss.

At least 91 records · Page 5Linked to original sources

The use of an external dacron shunt in repair of a supraceliac abdominal aorta traumatic aneurysm.

This is the sixth report in the English literature of survival following repair of a supraceliac aortic traumatic aneurysm secondary to penetrating injury. Symptoms, (12 months after a stab wound of the flank), led to discovery of an aneurysm 15 cm in diameter, originating from the left side of the supraceliac aorta. Repair was accomplished with a temporary thoracoabdominal bypass shunt graft of woven Dacron.

Adult↗

True venous aneurysms and arterial "steal" secondary to arteriovenous fistulae for dialysis.

In patients requiring hemodialysis, arteriovenous fistulae may be created using autogenous vessels or prosthetic grafts. Complications of such operations include thrombosis, infection, venous hypertension, pseudoaneurysm, congestive heart failure, true venous aneurysms, and arterial "steal" syndrome. Of these the last two are the least common. On reviewing the English literature (Medline search: 1969-1991) we found only 8 reported cases of true venous aneurysms secondary to creation of an arteriovenous fistulae for dialysis. Hemodynamic assessment has shown that arterial "steal" is frequently present distal to an arteriovenous fistula. However, these patients rarely have ischemic symptoms. Over the last 7 years 236 patients had arteriovenous fistulae created for hemodialysis at our institution. Three of these patients (1.2%) developed true venous aneurysms. One of these 3 patients (0.4%) also had severe hand claudication due to arterial "steal". All of these patients were treated successfully without any complications. The etiology and various therapeutic options for these rare complications are discussed.

Adult↗

The clinical utility of carotid duplex scanning.

We retrospectively compared the results of duplex scanning (DS) with contrast angiography (CAN) in the evaluation of 119 patients whose 238 carotid arteries were evaluated by both methods within a four-week period. The results of all patients were then categorized by two different definitions of severity of stenosis. Category A classified 1-29% stenosis as mild, 30-69% stenosis as moderate, and 70-99% diameter reduction as severe stenosis. Category B defined mild stenosis as 1-19% lumen diameter reduction, moderate as 20-49% stenosis, and severe as 50-99% stenosis. The findings by each classification were compared in 60 patients with hemispheric symptoms and in 59 patients with nonspecific symptoms. CAN was our "gold standard", and exhibited greater sensitivity, specificity, accuracy, and predictive values than DS. Carotid arteries with 70% stenosis were identified by DS with greater specificity, accuracy, and predictive values than were arteries with 50% stenoses. Only the sensitivity was comparable in categorizations A and B (80% and 83%). All parameters of measurement were superior in patients with hemispheric symptoms. DS alone cannot substitute for CAN in selecting patients for carotid endarterectomy because its error rate exceeded acceptable rates of complications for carotid artery surgery. The false positive rate of DS was 4%. DS failed to diagnose 7 of 19 carotid artery occlusions, 9 of 11 ulcerated plaques, 7 of 119 instances of aortic arch disease, and 13 cases of severe intracranial artery stenosis.

Blood Flow Velocity↗

Bullet embolism.

Bullet embolism is a rare complication of vascular trauma. During the last ten years we have treated six patients with bullet embolism. Three patients had inferior vena caval injuries with embolizations of the bullets to the heart or pulmonary arteries. Two had infrarenal aortic injuries with embolization to vessels of the lower extremities. One patient with a shotgun injury to the superficial femoral artery and vein had both arterial and venous embolizations. The site of vascular penetration was repaired in all six patients. All peripheral arterial bullet emboli were removed except for an asymptomatic shotgun pellet in the peroneal artery. One bullet was removed from a right atrium and another from a proximal pulmonary artery. Emboli in the distal pulmonary artery branches were left undisturbed in two patients. All six patients survived without any complications. A 14-year review of the literature is presented in order to emphasize some important features of this rare pathology.

Adult↗

Causes of limb loss in civilian arterial injuries.

Progress in the management of complex vascular injuries of the extremities has not eliminated the necessity for amputation. An analysis of 100 consecutive patients treated at the Lincoln Medical and Mental Health Center during 1974-1980 disclosed that five amputations followed 24 instances of blunt trauma, but only one minor amputation of toes was required in 76 patients after repair of arterial injuries associated with penetrating wounds. Extensive skeletal, muscular and skin loss at the sites of blunt trauma precluded salvage of two limbs. Physicians' failure to suspect arterial injury on admission in three patients with blunt trauma caused delay in the diagnosis and management of occlusive arterial injury that ultimately led to three amputations. In contrast, limited soft tissue damage accompanying penetrating wounds and high index of suspicion resulted in expeditious repair, accounting for the minimal risk of limb loss. Amputation may be obligatory in the presence of extensive skeletal and soft tissue destruction. However, limb loss due to delay in diagnosis is preventable. In every instance of blunt trauma to extremities, we advocate the same suspicion of vascular injuries as in penetrating trauma, with early liberal use of angiography whenever pulses are not absolutely normal, and prompt revascularization of ischemic limbs.

Adult↗

Changing patterns in civilian arterial injuries.

A critical review of 185 patients with 211 arterial injuries over an eleven year period was performed to recognize the changing patterns in clinical findings, management and results. A ten fold increase in multiple arterial injuries as well as higher incidence of associated venous and visceral injuries occurred during the last five years. Despite this, the incidence of hypotension on arrival at hospital was reduced by half due to rapid transportation and resuscitation during transit. Shock in patients with only extremity injuries heralded dual injuries (arterial and venous). Lateral repair of both arterial and venous injuries has given way to end to end anastomoses, vein grafts and patch grafts. A greater tendency to repair all major arteries, most minor arteries, more liberal use of heparin, fasciotomy, intraluminal shunts, repair of venous injuries and extra-anatomic bypass has been noted. Rapid patient retrieval, early resuscitation, improved recognition and management of arterial injuries has not lead to better limb salvage or survival. The apparent lack of benefit in limb salvage is probably due to the higher incidence of multiple arterial injuries and associated venous injuries as well as the willingness to attempt repair all major arterial injuries and reluctance to advise primary amputation. Early patient retrieval, rapid transportation and resuscitation during transit has increased the number of potentially unsalvageable patients (who would otherwise be declared dead on arrival) resulting in an unchanging mortality.

Accidents, Traffic↗

Simultaneous bilateral carotid endarterectomy operations.

Clinical reasoning and sound physiologic data have been the bases for performing bilateral simultaneous carotid endarterectomy operations in 25 patients recently. The results have compared favorably with unilateral carotid endarterectomy operations in 100 patients over the same time span. Thus, there is ample basis for performing operations simultaneously when bilateral carotid endarterectomy operations are indicated.

Adult↗

Arterial thrombosis and embolism in malignancy.

In most reviews of arterial embolism or thrombosis the source of emboli or the cause of thrombosis can reasonably be established in over 90% of patients. Still about 10% remain without demonstrable cardiac or intraarterial sources. Although hypercoagulability induced by malignancy has been alluded to as a cause of unexplained intravascular thrombosis reports of arterial thromboembolism with such association are rare. Seven patients with unequivocal thromboembolism are presented. Two distinct clinical patterns are observed, one with in situ thrombosis of small arteries and the other with occlusion of large arteries causing limb ischemia or fatal organ infarction. The various pathogenetic mechanisms of arterial thrombosis or embolism in malignancy include sustained spasm of arteries, precipitation of cryoglobulins or other abnormal proteins in small arteries, direct tumor invasion of arteries, fragmentation and embolization of intracardiac or intraarterial metastases and spontaneous arterial thrombosis due to hypercoagulability. The hypercoagulable state can be recognized by the observation of shortened bleeding and clotting times, partial thromboplastin and prothrombin times, elevation of coagulation factors, platelets and yield stress index and resistance to anticoagulation. Patients presenting with arterial thromboembolic events with out demonstrable source should be investigated for malignancy. Conversely patients with malignancy should be searched for evidence of hypercoagulability in an attempt to prevent arterial thromboembolic complications.

Adenocarcinoma↗