Posterior approach for cervical intramedullary arteriovenous malformation with diffuse-type nidus - Report of three cases

The treatment of spinal intramedullary arteriovenous malformations (AVMs) w ith a diffuse-type nidus that contains a neural element poses different cha llenges compared with a glomus-type nidus. The surgical elimination of such lesions involves the risk of spinal cord ischemia that results from coagul ation of the feeding artery that, at the same time, supplies cord parenchym a. However, based on evaluation of the risks involved in performing emboliz ation, together with the frequent occurrence of reperfusion, which necessit ates frequent reembolization, the authors consider surgery to be a one-stag e solution to a disease that otherwise has a very poor prognosis. Magnetic resonance (MR) imaging revealed diffuse-type intramedullary AVMs i n the cervical spinal cords of three patients who subsequently underwent su rgery via the posterior approach. The AVM was supplied by the anterior spin al artery in one case and by both the anterior and posterior spinal arterie s in the other two cases. In all three cases, a posterior median myelotomy was performed up to the vicinity of the anterior median fissure that divide d the spinal cord together with the nidus, and the feeding artery was coagu lated and severed at its origin from the anterior spinal artery. In the two cases in which the posterior spinal artery fed the AVM, the feeding artery was coagulated on the dorsal surface of the spinal cord. Neurological outc ome improved in one patient and deteriorated slightly to mildly in the othe r two patients. Postoperative angiography demonstrated complete disappearan ce of the AVM in all cases. Because of the extremely poor prognosis of patients with spinal intramedull ary AVMs, this surgical technique for the treatment of diffuse-type AVMs pr ovides acceptable operative outcome. Surgical intervention should be consid ered when managing a patient with a diffuse-type intramedullary AVM in the cervical spinal cord.