Carotid endarterectomy, carotid artery shunting and outcome: an historical perspective

Carotid endarterectomy is now celebrating its 50th anniversary! Yet, despite millions of these operations having been performed, there is little agreement about the best methods of surgical technique, cerebral protection, anesthetic technique and monitoring methods. In this time of evidence-based medicine, carotid endarterectomy fares badly, with only the indications for the surgery having been subjected to the appropriate methodology of clinical trials and biostatistics for proper evaluation. This review is designed to look back over the history of carotid endarterectomy in order to understand the evolution of current practices. Within the past 5 years, despite the publication of many papers dealing with issues surrounding carotid shunting, no randomized controlled trials evaluating this aspect of carotid artery surgery have appeared. One must probe further into the past to understand how so much can be written yet so little learned! Current evidence is not able to support the hypothesis that shunting during carotid artery surgery reduces the risk of perioperative stroke or death or that its use is associated with an increase in perioperative or long-term complications. Routine, selective or no shunting protocols during carotid artery surgery remain a matter of local custom and tradition.