Arteriovenous malformation of spinal cord --clinical symptoms, diagnosis and operation-- (author's transl)

Abstract

Twelve cases of arteriovenous malformation (AVM) of the spinal cord were operated on at the Department of Neurological Surgery, Kitano Hospital, from July 1972 through August 1975. They included three cases of intramedullary spinal cord AVM and nine cases of extramedullary spinal cord AVM (Table). Initial symptoms were due to ischemia of the spinal cord in two cases and to subarachnoid hemorrhage in the remaining 10 cases. In five out of those 10 cases, predisposing factors causing subarachnoid hemorrhage were pregnancy, upsidedown standing, massage of the neck, neck-flexion on hair washing, and twisting of the waist. Those movements increased the venous pressure of the spinal cord, then the blood pressure in spinal cord AVM, and resulted in subarachnoid hemorrhage. For the diagnosis of spinal cord AVM myelography was done first, followed by spinal angiography. Spinal angiography was the most important diagnostic procedure preoperatively, because it gave valuable informations concerning the num bers and the location of the feeding arteries, the site and the size of spinal cord AVM, the numbers of drainage veins and the direction of blood flow. Since most of the spinal cord AVMs were located at the dorsal surface of the spinal cord with a few feeding arteries, they could be removed relatively easily by posterior approach after laminectomy. On the contrary, spinal cord AVMs with a number of feeding arteries, particularly those which were mainly fed by the anterior spinal artery, had been considered to have no surgical indication. However, we operated on three cases of intramedullary spinal cord AVMs which were mainly supplied by anterior spinal artery. The operative procedures were as follows : After myelotomy with microsurgical techniques, the tissues surrounding the spinal cord AVM were dissected to reach the anterior spinal artery. After coagulation of the feeding artery, the spinal cord AVM was totally removed. Although these procedures were followed by a transient aggravarion of clinical symptoms, there have been no serious sequelae persistent.