Prediction of outcomes for brainstem cavernous malformation.

OBJECTIVE: Brainstem cavernous malformation (CM) poses a challenge to neurosurgeons in terms of operability, postoperative complications and unpredictable outcomes. The present study was conducted to analyze the clinical parameters that might predict the outcomes and to summarize our center experience in treatment of brainstem CM.

METHODS: A total 59 patients with radiological and histologically confirmed brainstem CM diagnosed between 2000 and 2012 were retrospectively reviewed. All but five patients were deemed amenable to surgical resection. Complete resection was attempted in all CM and was achieved in 58/59 patients. Modified Rankin scale (mRS) score dichotomized as mRS 0-2 (favorable outcome) or mRS 3-6 (unfavorable outcome) was employed for neurological status assessment. The association of various clinical parameters to the different brainstem location was evaluated. Predictors of the surgical outcomes were analyzed using the univariate and multivaraite regression statistics.

RESULTS: Mean age of 32 female and 27 male patients was 34.3 years. The differences in size of cavernoma, conservative treatment and complications were significantly associated with various location of the CM in the brainstem. Clinical parameters including age at presentation (p=0.029, OR=0.061, CI=0.009-0.414), favorable preoperative mRS (p=0.004, OR=0.058, CI=0.009-0.343), pontine location of CM (p=0.018, OR=0.017, CI=0.001-0.495), and early surgical treatment (p=0.05, OR=0.087, CI=0.07-1.03) were independent predictors of favorable surgical outcomes. Mean long-term follow up of 42.9 months was available in 31/59 (52.5%). The mean size of CM was 22.5 mm; small size (<10 mm) at presentation was associated with favorable outcomes at long-term follow-up (univariate analysis, p=0.041, adjusted R2=0.471). Preoperative mRS (p=0.039) and location of the CM (p=0.034) in the brainstem were predictors of good surgical outcomes at long term follow-up.

CONCLUSION: Favorable surgical outcomes can be predicted in brainstem CM patients with early age at presentation, pontine location of the cavernoma, favorable preoperative mRS and those undergoing early surgery. The outcomes at long-term follow-up were associated with location of the CM in the brainstem, size of the CM and the preoperative mRS.