Extracranial-intracranial arterial bypass for giant aneurysms.

We describe in detail one case, and briefly mention another where occlusion of a main vessel was necessary for removal of an aneurysm sac. The combined surgery of extracranial-intracranial bypass and the removal of the aneurysm at a second operation four to five weeks later is reported. The two-stage procedure is preferable to the one-stage proceeding for better assessment of the patency of the anastomosis and the possibility of undertaking a second attempt at anastomosis if the first bypass should become occluded.