The Correlation Between Hematoma Volume and Outcome in Ruptured Posterior Fossa Arteriovenous Malformations Indicates the Importance of Surgical Evacuation of Hematomas

Abstract

Aim: The correlation between hematoma volume and outcome in ruptured arteriovenous malformations (AVM) with accompanying posterior fossa hematoma was retrospectively evaluated. Material and Methods: Microsurgery operations were performed on 127 patients with intracranial AVM between January 1998 and January 2009 at our clinic. Fifteen (11.8%) patients were identified as suffering from posterior fossa AVM, and twelve of these patients presented with a cerebellar hematoma. All patients were clinically evaluated according to the following criteria: modified Rankin Scale (mRS) prior to surgery, Spetzler-Martin grade (SMG) of the AVMs, hematoma volume prior to surgery, and mRS following surgery. Results: Postoperative mRS scores were significantly lower than preoperative scores (p=0.0001). Postoperative outcomes were concordant with the SMG of the AVMs (r=0.67, p=0.033), hematoma volume (r=0.537, p=0.072) and preoperative mRS scores (r=0.764, p=0.004). These analyses show that the postoperative mRS score is strongly correlated with a preoperative mRS score, hematoma volume and SMG. Conclusion: Posterior fossa AVMs present an increased risk for hemorrhage and for increased morbidity and mortality. Cases with hematoma should be operated on an urgent basis. We conclude that hematoma volume is a factor that impacts postoperative results and prognosis. SMG and preoperative mRS scores were also correlated with outcome.