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.