Tandem bypass: occipital artery to posterior inferior cerebellar artery side-to-side anastomosis and occipital artery to anterior inferior cerebellar artery end-to-side anastomosis--a case report.

A unique example of posterior fossa revascularization is presented. A tandem bypass was performed by anastomosing the midoccipital artery to the posterior inferior cerebellar artery in a side-to-side fashion followed by anastomosis of the distal occipital artery to the anterior inferior cerebellar artery in an end-to-side fashion. The operation was designed to revascularize two separate vascular territories that were isolated in a patient thought to have an extremely compromised posterior circulation. The patient is doing well and is asymptomatic 3 years postoperatively.

Vertebrobasilar insufficiency. A review.

After critically reviewing the last 50 years' literature pertaining to vertebrobasilar insufficiency, we reached the following conclusions: One can seldom accurately localize vascular pathologic lesions in the posterior circulation by clinical examination alone. The symptoms of vertebrobasilar insufficiency have multiple causes. Stenotic and occlusive lesions have been found at every level of the vertebrobasilar circulation. Currently, a complete investigation requires four-vessel cerebral angiography. No therapeutic modality, medical or surgical, has been proved unequivocably to be of benefit. New surgical approaches to the vertebrobasilar circulation that show promise in providing alternative methods of treatment have been developed.