Vascular compression of the optic nerves relieved by anastomosis of carotid artery to jugular vein.

The intracranial segment of the optic nerve, crossed near the chiasma by the anterior cerebral artery and fixed anteriorly at its entry into the optic foramen, is particularly vulnerable to compression by vascular deformities of the internal carotid artery or its branches. Aneurysms arising in this region may be surgically inaccessible directly, because of their size or because they arise from that segment of the carotid between its exit from the cavernous sinus and the anterior clinoid process. Expansion of these aneurysms results in pain and associated blindness or visual field defect due to optic nerve compression. The orthodox surgery for such aneurysms is carotid ligation. This is a step that cannot be retraced and, if it fails in its objective, it is difficult to justify the very disabling complications. As an alternative to carotid ligation the blood flow through the carotid artery can be reduced by creating a small arteriovenous shunt between the carotid artery and the jugular vein in the neck. This technique has been used since 1966 and there have been no complications from the shunting operation in its use for space occupying aneurysms and no long-term effects on the cardiovascular system in the form of alteration of exercise tolerance, cardiac size, or electrocardiographic changes. This is a report on two cases of aneurysm and one of compression of the optic nerve by a dilated and tortuous ophthalmic artery in a patient suffering from acromegaly.