Surgery of cerebral arteriovenous malformations

Despite remarkable progress, the microsurgical extirpation of cerebral arteriovenous malformations (AVMs) even by experienced neurosurgeons is not always easy or safe. This article focuses on how to render AVM surgery safer, and offers strategies and tactics for avoiding perilous bleeding and preserving postoperative neurological function. Our treatment strategies and surgical techniques are offered from the operating surgeon's perspective. An understanding of pathophysiology of cerebral AVMs is important for their appropriate surgical treatment. Sophisticated neuroirnaging techniques and scrupulous neurophys i o logical examinations alert to possible complications, and improved surgical approaches help to minimize the sequelae of unanticipated complications. At the early stage of cerebral AVM surgery, extensive dissection of the sulci, fissures, and subarachnoid cistern should be performed to expose feeders, nidus, and drainers. Problems with the surgery of large and/or deep-seated lesions are exacerbated when arterial bleeding from the niclus continues even after all major feeders are thought to have been occluded. We routinely place catheters for angiography at the surgery of complex AVMs to find missing feeding arteries or to identify the real-time hemodynamic status of the lesion. Temporary clip application on feeders and less coagulation of the nidus is necessary to control intraniclal pressure and to avoid uncontrollable bleeding from the nidus and adjacent brain. Intraoperative navigation images superimposed on tractography images can provide us with valuable information to minimize neurological deficits. Deeper insight into AVM nature and into events that occur during AVM surgery as well as the inclusion of molecular biological approaches will open new horizons for the safe and effective treatment of AVMs.