Surgical Strategies in Treating Brainstem Cavernous Malformations

BACKGROUND: Optimal therapy of brainstem cavernous malformations (BSCMs) remains controversial because their biological behavior is unpredictable and surgical removal is challenging. OBJECTIVE: To analyze our experience with BSCMs and to conduct a review of the literature to identify a rational approach to the management of these lesions. METHODS: Fifty-five patients harboring 57 BSCMs underwent surgery and 17 patients were treated conservatively during the 10-year period from 1999 to 2008. The operative strategy was to perform complete CM resection and to preserve any associated venous malformation with minimal functional brainstem tissue sacrificed. The National Institutes of Health Strength Scale (NIHSS) was used to assess neurological status. RESULTS: The average hemorrhagic and rehemorrhagic rates were 4.7% and 32.7% per patient-year, respectively. Total lesional resection was achieved in all operated patients. Their mean NIHSS score was 4.6 after the first episode, 3.5 preoperatively, 3.2 at discharge, and 1.4 after a mean follow-up of 49 months. Complete recovery rates of motor deficits and sensory disturbances from the preoperative state were 70.4% and 51.7%, respectively. Complete recovery rates for cranial nerves III, V, VI, and VII and the lower group were 60%, 63.2%, 25%, 57.1%, and 80%, respectively. For the conservative patients, the mean NIHSS score was 5.9 after the first episode and 1.7 after a mean followup of 40 months. CONCLUSION: NIHSS is optimal for evaluating the natural history and surgical effect of patients harboring BSCMs. Surgical resection remains the primary therapeutic option after careful patient screening and preoperative planning.