Faculty Bibliography

Dilation of prosthetic graft has been noted by authors in association with junctional aneurysm between the synthetic graft and host arteries. Dilation of graft materials was suspected as one of the etiologic factors of the junctional aneurysm. Increase in transverse diameter was observed as early as a few minutes to five years postimplantation in clinical cases. The phenomenon of dilation was studied experimentally. Nine different types of graft materials were tested using intraluminal pulse pressure of 100/60 mm Hg, and the transverse diameters were measured at various time intervals. Knitted grafts showed the more pronounced changes compared with the woven. Degree of dilation differed considerably among the different types of knitted grafts

Acute aortic occlusion is most often seen in elderly patients with advanced cardiac disease. The management of these patients has been facilitated by the use of extraanatomic bypass. Over the past 2 years, six patients aged 55 to 87 years presented to our medical center with acute aortic occlusion, three after major operative procedures. One patient had a thrombosed abdominal aortic aneurysm; in the other five patients differentiation between saddle embolus and thrombosis of the distal aorta was impossible. There was one operative death. Four of the other five patients underwent axillobifemoral bypass and one underwent aortofemoral thrombectomy. All survived, and none required amputation. Two of the three patients who underwent preoperative aortography developed transient renal failure postoperatively. Aortography is of little value in diagnosis and is probably contraindicated in acute aortic occlusion. Our recommendation for operative management includes (1) preparation of the patient for possible axillobifemoral bypass, (2) angiography of distal runoff via both femoral arteries, (3) attempt at bilateral aortofemoral embolectomy with Fogarty catheters, and (4) axillobifemoral bypass if embolectomy fails to restore normal pulsatile flow

Embolization from or decreased flow through cervical carotid and vertebral arteries causes ischemic stroke syndromes. Specific pathologic findings were studied in 50 symptomatic patients who underwent 69 carotid endarterectomies. Detailed analyses of their carotid plaques included correlations between photographs of gross specimens, microscopic findings, angiograms, preoperative symptoms and long-term postoperative follow up. Carotid plaques were primarily fibrous with significant (greater than 70%) stenoses encountered in 70% of the arteries. Stenoses were due to simple fibrous thickening in only 20%; the remainder due to intraplaque hemorrhage, atheromatous debris and, least often, luminal thrombus with or without ulceration. Intramural hemorrhage was frequent in plaques associated with focal neurologic symptoms and may have preceded localized collections of atheromatous debris. Ulceration occurred in 1/3 of all plaques, symptomatic or not. It is concluded that the carotid plaques start as fibrointimal thickening evolving to symptomatic stages by the occurrence of one or more of a number of pathologic changes, intraplaque hemorrhage being prominent. A single rational therapeutic regimen seems impossible until patients can be classified according to their pathologic changes diagnosed non-invasively

In a series of 683 consecutive carotid endarterectomies, there were 16 postoperative myocardial infarctions which resulted in five deaths. Of 399 operations on patients with no previous history of heart disease, there were only two myocardial infarctions (0.5%). Two hundred and eighty-four operations were performed on patients with heart disease, and vasopressors were administered in 135 of these procedures. For these patients the risk of myocardial infarction increased from 2.0% to 8.1% with the use of vasopressors (P less than 0.001). The management of the patient with stable heart disease undergoing carotid endarterectomy is discussed

A presumed new radiological-pathological entity of atherosclerotic subintimal of the carotid artery is described. Subintimal hematomas were found in 12 of 50 (24%) carotid bifurcations during surgery for repeated transient ischemic attacks in a single hemispheric distribution; only 33% were associated with ulcerations. The typical angiographic appearance was a sharply marginated, rounded, eccentric filling defect located near the extracranial carotid bifurcation, although occasionally it may simulate a typical smooth or even ulcerated atherosclerotic plaque. Pathological mechanisms responsible for the hemorrhage into the atherosclerotic plaque resulting in the hematoma are discussed

The accuracy of angiographic diagnosis of carotid artery ulceration was evaluated. Of those carotid bifurcations showing ulceration at surgery, 60% were diagnosed as having ulcers at angiography. Half of the remaining ulcers occurred in smooth, benign-appearing plaques and were too small to be seen at angiography. An incorrect angiographic diagnosis of ulceration was made in 17 of 50 carotid arteries; in most cases this was due to the presence of a subintimal hematoma in the wall of the artery

A randomized prospective study of low dose heparin was performed in 175 surgical patients to determine the frequency of bleeding and wound complications. The patients were divided into three groups: (1) low dose heparin (5000 units two hours before operation and 5000 units every 12 hours following operation for five days); (2) low dose heparin postoperatively only; and (3) a control group. The frequency of bleeding and wound complications was 27% in group I, 7.5% in group II, and 1.4% in group III. The difference between the control patients and those heparinized pre- and postoperatively is statistically significant (p less than 0.005). None of the patients in any of the three groups had a pulmonary embolus, but the number of patients involved is too small to assess the significance of this finding. However, a bleeding and wound complication rate of 27% is significant. These findings indicate that perhaps the routine use of low dose heparin should be reserved for those patients with preoperative factors indicating an increased risk from thromboembolism