Carotid artery spasm. A cause of postendarterectomy thrombosis?

Carotid endarterectomy is generally regarded as a durable repair, with a low incidence of postoperative thrombosis. However, unexpected, inexplicable occlusions and pressure-flow aberrations have been reported to occur during the period immediately after operation period. We studied 245 operative angiograms obtained during a series of 335 carotid endarterectomies. Among the various defects noted were 24 instances of mild to severe spasm of the middle and distal extracranial carotid artery. This spasm was remote from the endarterectomy site and often was entirely beyond the field of operative exposure. Early and late postoperative angiograms demonstrated that this may be a transient phenomenon, and repeated intraoperative films documented that spasm may progress without further direct instrumentation of the involved segment. The patient who demonstrated the most severe spasm later suffered immediate postoperative occlusion and stroke despite a technically satisfactory repair.