The repair of stenotic lesions of the internal carotid artery is now done as a standard operation. The obstructing lesion usually extends only a short distance above the bifurcation, and distal control of the artery is easily secured. Furthermore, the stenotic lesion has usually stimulated the development of intracranial collateral supply so that the flow of blood can be safely interrupted for repair of the artery. Aneurysms of the extracranial internal carotid artery, on the other hand, are much less common. The distal vessel may be difficult or impossible to control, and there may be no protection against the ischemia brought about by cross-clamping the carotid artery during repair. In recent years resection and restoration of flow has been performed with increasing frequency in spite of these inherent hazards. In 1964, Halasz and Kennady1 summarized eight cases, including one of their own. Since then at least ten other authors