Bypass Surgery: Indication, Timing, and Effectiveness

Abstract

While the value of extracranial to intracranial (EC-IC) bypass operations in conjunction with planned major cerebral vessel occlusions for the treatment of aneurysms and tumors remains well-recognized, the usefulness of such surgery for any atherosclerotic cerebrovascular disease is controversial. Results of the EC-IC bypass trial have led to categorical statements by the principal investigators that there is no indication for EC-IC bypass for any atherosclerotic disease of the anterior circulation. Revelations regarding large numbers of patients operated outside the trial by participating centers cast some doubt on these conclusions. It is necessary to get clinical and follow up data on the patients undergoing superficial temporal to middle cerebral artery (STA-MCA) bypass at participating centers but who were withheld from the study to assess the meaning of the cooperative study. Our own experience with bypass includes 415 STA-MCA anastomoses for atherosclerotic cerebrovascular disease in 403 patients, seven superficial temporal to superior cerebellar artery anastomoses, 41 occipital artery to posterior inferior cerebellar anastomoses, and 146 saphenous vein grafts, atherosclerotic disease, and aneurysms of the anterior and posterior circulations. Current indications, operative technique, and analysis of results are to be presented.