Is carotid endarterectomy justified in patients with severe chronic renal insufficiency?

We evaluated the effect of chronic renal insufficiency (CRI) and commonly associated co-morbid conditions on the risk of adverse events (stroke, cardiac events, and death) within 30 days after carotid endarterectomy (CEA). Renal function of patients undergoing CEA from 1980 to 1994 was categorized as normal (creatinine < 1.5 mg/dl), mild CRI (creatinine 1.5-2.9 mg/dl), or severe CRI (creatinine > 2.9 mg/dl). Renal function, age, gender, indications for surgery, cardiac disease, chronic preoperative hypertension, diabetes mellitus, smoking history, severe perioperative hypertension or hypotension, intraoperative shunting, and patch closure of the carotid artery were evaluated for their influence on the incidence of adverse events within 30 days after surgery. The timing of postoperative stroke and mechanism of stroke was determined when possible. A total of 237 patients underwent 285 CEAs. No significant differences were found in demographic or clinical characteristics between patients with normal or abnormal renal function. Postoperative stroke and death occurred following three (43%) of seven CEAs in six patients with severe CRI, significantly greater than the 6% incidence of stroke and 1% mortality following 264 CEAs in 221 patients with normal renal function (p < 0.001 and p < 0.001, respectively). Of three patients with severe CRI suffering postoperative stroke, two had severe, difficult to control perioperative hypertension. Two patients with severe CRI who survived 30 days after operation suffered strokes 3 and 4 months postoperatively with one stroke-related death and another death not directly related to the stroke. One patient with severe CRI who survived CEA without stroke was alive 6 months after surgery. The 0% incidence of stroke and death following 14 CEAs in 10 patients with mild CRI was not significantly different from that in patients with normal renal function. Postoperative stroke was not associated with age, gender, history of cardiac disease, chronic preoperative hypertension, diabetes, smoking, or use of intraoperative shunts or patch closure. All three cardiac events occurred in diabetic patients, although they constituted only 26% of operations (p = 0.003). Other clinical characteristics were not associated with the occurrence of cardiac events. Patients with severe CRI are at significantly greater risk than others for postoperative stroke and death following CEA, possibly related to difficulty controlling severe perioperative hypertension. Age, gender, smoking, preoperative hypertension, diabetes, and known cardiac disease are not associated with an increased risk of postoperative stroke in any patient group. CEA can be justified only for carefully selected patients with severe CRI who have symptomatic carotid disease, acceptable operative risk factors, and a good long-term life expectancy. CEA in patients with mild CRI is associated with low risk, and these patients may be treated with the same consideration as patients with normal renal function.

Criteria for selective utilization of the intensive care unit following carotid endarterectomy.

The common practice of admitting all patients to an intensive care unit (ICU) following carotid endarterectomy (CEA) is based upon concern for adverse events that may be properly cared for only in the ICU. We developed restrictive criteria for postoperative nursing unit admission based on analysis of adverse outcomes and risk factors. 365 CEAs over 15 years were reviewed. In the first 24 hours after CEA, 38 patients experienced 46 events that may have been best managed in an ICU. Preoperative factors associated with significant risk for complications were indications of cardiac disease within 6 months (n = 62, p < 0.05), emergent CEA (n = 2, p = 0.01), and need for postoperative anticoagulation (n = 2, p = 0.01). Only 56 (15%) of patients had indications for ICU admission, 57 (16%) would have been admitted to an EKG-monitored nursing unit, and 252 (69%) would have been admitted to a standard nursing unit. Immediate admission to the ICU after CEA is indicated for patients undergoing emergent CEA, those requiring anticoagulation postoperatively, those with intraoperative stroke or major cardiac complication, and possibly those with chronic renal failure. All other patients should be admitted to the RR. Patients experiencing stroke, major cardiac events, significant wound hemorrhage, or reintubation in the RR, and those requiring vasoactive medication more than 3 hours after surgery should be transferred to the ICU. Patients with indications of cardiac disease within 6 months prior to CEA but no indications for ICU admission may be discharged from the RR to an EKG monitored unit. All others may be discharged to a standard nursing unit.

Aneurysms of the superficial femoral artery: a report of two cases and review of the literature.

True "arteriosclerotic" aneurysms of the superficial femoral artery, not associated with generalized dilatation of the common femoral or popliteal artery, are relatively rare. We report our experience with two isolated superficial femoral artery aneurysms and review the previous literature. An 88-year-old woman was first seen with thrombosis of a superficial femoral aneurysm and limb-threatening ischemia and had eventual limb loss as a result of occlusion of distal run-off vessels despite surgical revascularization. A 93-year-old man came to us with rupture and was treated with an interposition graft, which resulted in limb salvage. Review of 17 "arteriosclerotic" superficial femoral artery aneurysms in 14 patients whose cases were reported in the literature revealed a complication at presentation in 65%, rupture in 35%, thrombosis in 18%, and distal emboli in 12%. However, limb salvage was 94% and there were no perioperative deaths. Abdominal aortic aneurysms were discovered in 40%. Males (75%) were more common than females, and the average age was 77 years (range 61 to 93). Isolated superficial femoral artery aneurysms are rare and occur at an older average age than do other peripheral aneurysms, but their incidence is anticipated to increase with this growing segment of our population. In the absence of evidence of syphilitic, other infectious, immunologic, inflammatory, or connective-tissue disorders, these and other aneurysms are considered arteriosclerotic in origin, despite the absence of diffuse arteriosclerosis in many cases and controversy regarding the role of arteriosclerosis in their cause.(ABSTRACT TRUNCATED AT 250 WORDS)

Microvascular endothelial cell seeding of small-diameter Dacron vascular grafts.

One obstacle to the clinical implementation of endothelial cell seeding of vascular prostheses is the difficulty in derivation of large numbers of autologous endothelial cells from blood vessels of patients requiring vascular grafting. Capillary endothelial cells obtained from fat have been suggested as an abundant alternative to large-vessel endothelium for graft seeding. The object of this study was to evaluate the performance of 4-mm internal diameter (ID) Dacron Microvel grafts seeded with omentally derived microvascular endothelial cells. Six-cm lengths of the test grafts were implanted bilaterally into canine carotid arteries. One of each pair of grafts was seeded with endothelial cells (means = 8.4 x 10(6)) derived from collagenase digestion of autologous omental fat samples. The contralateral graft of each pair was nonseeded. At 5 weeks postoperatively, the grafts were harvested and evaluated. The mean patencies of both the seeded and nonseeded grafts were 89 percent. The mean thrombus-free surface area for seeded grafts was 95 +/- 11 percent. This value was significantly different statistically from the mean thrombus-free surface area of nonseeded grafts, which was 43 +/- 19 percent (P less than .05). Histologically, midgraft regions of seeded grafts were cellular, stained positive for collagen, and were characterized by inner capsules ranging in thickness between 35-94 microns. Luminal cells were identified as endothelial by peroxidase antiperoxidase staining techniques. Midgraft regions of nonseeded grafts demonstrated thrombus accumulation, limited cellularity, and inner capsules between 59-194 microns thick. Scanning electron microscopy of seeded grafts revealed smooth luminal surfaces with tight junctions between adjacent cells; surface cells were not present on midgraft regions of nonseeded grafts. In conclusion, endothelial cells derived from omental fat successfully surfaced on Dacron grafts and imparted characteristics to the graft that would predict long-term graft success.