Cerebrovascular Response to Emboli

Introduction

Selective enlargement of the primary feeding arteries to large cerebral arteriovenous malformations and the relatively greater blood flow through these arteries can create direct, enlarged channels from the cervical carotid and vertebral arteries to the malformation. As these enlarged feeders enter the malformation they usually ramify into multiple smaller arteries, except in unusual cases of direct artery-to-vein communication.^1,2The anatomical and hemodynamic situation thus created may permit safe surgical embolization from the cervical arteries provided the emboli fit easily within these main channels and are too large for acceptance by the smaller side-branches to the surrounding normal brain. We are evaluating the extent to which artificial embolization may be useful in the treatment of certain large cerebral arteriovenous malformations and, with certain modifications, bleeding saccular aneurysms. Since reporting the first case, in which only 4 emboli were used,³we have now studied the intravascular behavior of 471