Temporary hypotension following endarterectomy for severe carotid stenosis: should we treat it?

In patients with severe carotid stenosis, the author has observed that temporary low blood pressure often occurs in the postoperative period. The hypotension typically develops 2 to 4 hours following operation, is asymptomatic, and resolves within 12-24 hours. In recent years treatment has consisted of simple observation, avoiding the use of vasopressors. Other reports of hemodynamic instability following carotid endarterectomy emphasize high blood pressure. The author rarely observes postoperative hypertension in his practice and has wondered if technical factors explain the difference. A consecutive series of primary carotid endarterectomies recently performed by the author was prospectively studied to determine the incidence of postoperative hypotension. Forty-nine of 180 consecutive patients (27%) developed hypotension below 90 mm Hg systolic (range 65-90). All had severe stenosis as an indication for operation. Only 1 patient required treatment for symptoms related to the low blood pressure. Simple observation of the remaining 48 patients with postoperative hypotension did not result in complications nor delay discharge. Data management, selection of patients, surgical technique, and results are discussed. Temporary postoperative hypotension in patients with severe carotid stenosis is common and appears to be benign. The author speculates that this phenomenon may protect ischemic brain tissue from sudden hyperperfusion, and as such should not be treated with vasopressor medication unless symptoms are present.