Surgical Treatment for Late Complications following Gamma Knife Surgery for Arteriovenous Malformations

Abstract

Cyst formation is one of the late complications of GKS for AVM. Some cysts show spontaneous regression but others gradually increase in size and become symptomatic, although relatively large asymptomatic cysts are also known. Predicting the future course of a cyst is difficult. Surgery such as placement of an Ommaya reservoir should be considered for symptomatic cases. Expanding hematoma always increases in size and becomes symptomatic, so removal by craniotomy is necessary. Surrounding brain edema decreases rapidly after surgery and neurological symptoms quickly resolve.