Extracranial-intracranial bypass for giant aneurysms and complex vascular lesions: a clinical series of 10 patients.

Aim. The purpose of this clinical study is to evaluate the preventive bypass indications, the kind of bypass to use, and the timing of postoperative internal carotid artery (ICA) occlusion in the treatment of complex aneurysms. Methods. This study enrolled 10 patients suffering from complex aneurysms treated using several kind of extra-intracranial bypass on the basis of preoperative careful assessment of cerebrovascular flow. This assessment is based on the balloon test occlusion (BTO), from which three different conditions emerge. According to the Department of Neurosurgery these three different conditions require three different kinds of bypass: in case of depleted flow a short STA-MCA bypass is necessary, in case of intermediate flow a long arterial graft bypass is required, whereas in case of high flow a long venous graft bypass is mandatory. Results. Bypass patency was found in six out of seven patients who underwent surgery for giant ICA aneurysms, as well as in other patients. One of the patients died for a septic shock, another had a neck hematoma that required surgical evacuation. At mean follow-up no further neurological deficits were found. Conclusion. The severe complications due to the combined approaches can be reduced thanks to the indications obtained by BTO concerning the kind of bypass to perform and to the timing of the ICA occlusion