Lies, Damned Lies, and Statistics∗: A Neurosurgical Perspective on the International Randomized Trial of Extracranial to Intracranial Arterial Bypass Surgery

The abrupt occurrence of a devastating stroke has been referred to as ”super death.” It has long been realized that ischemic cerebral vascular disease may become symptomatic with a wide variety of clinical patterns. A robust circle of Willis has been recognized for its major protective function in many cases. When it became possible to actually create new collateral circulation to the brain by microsurgical techniques, significant enthusiasm arose. This enthusiasm was interrupted by the negative results of the international randomized trial. Further analysis of the trial raised serious questions regarding incomplete randomization by contributors to the study, and there remains uncertainty about important potential benefits for some individuals. Long-term follow-up of 3 patients having different and complex circumstances is described to emphasize this concern. After the creation of reliable collateral circulation to the brain, none has experienced new ischemic deficit during the subsequent follow-up of 27, 25, and 12 years, respectively.