Haemorrhage from a radiosurgically treated arteriovenous malformation after its angiographically proven obliteration: a case report.

Small lower-grade Spetzler-Martin arteriovenous malformations (AVMs) are mainly treated by microsurgical resection or stereotactic radiosurgery. The choice of treatment largely depends on the referring centre's preference and the patient's decision. We present here a patient with an AVM repeatedly treated at our Leksell Gamma Knife unit with radiographically confirmed obliteration of the AVM which subsequently began bleeding. This case demonstrates the possibility of late complications in radiosurgically treated AVMs even after their demonstrable obliteration. Meticulous histological examination was performed, proving patency of the AVM nidus. The risk of haemorrhagic complications of radiosurgically removed AVMs despite angiographic proof of their obliteration is, in our view, a cogent argument for preferring surgical resection if the AVM is accessible and for prolonged follow-up after radiosurgical treatment of an AVM.