Postoperative evaluation of microsurgical resection for cavernous malformations of the brainstem

Abstract

Object. The aim of this study was to propose criteria to determine whether complete resection of cavernous malformations in the brainstem had been achieved. Methods. The authors retrospectively analyzed data in 10 patients harboring a single cavernous malformation who had presented with hemorrhagic symptoms and had been followed up for longer than 2 years postsurgery. The study population consisted of five male and five female patients ranging in age from 13 to 57 years (mean 36.8 years). When preoperative magnetic resonance (MR) images demonstrated the lesion as a homogeneous hyperintense mass, the surgery was defined as complete or incomplete based on intraoperative findings. When preoperative MR images revealed other findings, complete resection was determined according to whether postoperative MR imaging results demonstrated lesions distinct from the peripheral hemosiderin rim. Among the 13 operations in this series, nine resulted in complete resection and were associated with no postoperative clinical relapse of hemorrhage, whereas four operations resulted in incomplete resection and were correlated with postoperative recurrent hemorrhage. The seven patients in whom the outcome of the initial operation was complete demonstrated good neurological recovery in the long-term follow-up period, whereas the three patients in whom the outcome of the initial surgery was judged to be incomplete showed inadequate neurological recovery due to recurrent hemorrhage. Conclusions. The criteria proposed in this study to evaluate surgical treatment may be a reliable means of predicting the recurrence of hemorrhage postoperatively.