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Arterial Collateralization after Common Carotid Ligation

The two major indications for common or internal carotid ligation are the resection of neoplasm and the control or prevention of hemorrhage. Sixty percent of those undergoing elective carotid ligation and 12% of those undergoing emergency ligation survive these procedures without evidence of neurological sequelae. This uncompromised survival is based upon the presence or rapid developmnt of collateral circulation to the cerebral vascular bed. Arteriographic studies are utilized to illustrate the development of intra- and extracranial collateralization to the internal carotid artery after interruption of the ipsilateral common carotid. The major collateral circuits demonstrated via a case report are as follows: 1) from the vertebral artery to the external carotid and hence to the internal carotid; 2) from the posterior communicating artery to the internal carotid; and 3) from the ophthalmic artery to the internal carotid.