Late stenosis of a superficial temporal-middle cerebral artery bypass: angiographic and histological findings.

The course of a patient with an initially widely patent superficial temporal artery-middle cerebral artery (STA-MCA) bypass and an enlarged donor vessel is presented. Over 17 months, the STA became markedly stenotic. Serial angiography is correlated with autopsy histological findings showing severe atherosclerotic changes throughout the donor vessel. The potential causative factors, both medical and surgical, are discussed and the appropriate literature is reviewed. Parallels are drawn from the cardiac bypass experience. The bypass itself may have precipitated or accelerated intimal hyperplasia, which stenosed (and may have eventually occluded) the vessel. Is this phenomenon more frequent than we realize?