Brainstem Cavernous Malformations Resected Via Miniature Craniotomies: Technique and Approach Selection

Objective: Brainstem cavernous malformations (BCMs) are benign tumors but can cause devastating neurologic disability when they hemorrhage. Annual symptomatic bleed rates are higher for lesions in the brainstem as compared with other locations, reported as high as 60.9%. We present a case series of patients who underwent surgical resection for a variety of BCMs using minimally invasive craniotomies (MICs). Methods: Approach was chosen by location of the presentation of the BCM to the brainstem surface and the long axis of the lesion. Once the lesion was accessed, resection occurred through our described standardized method. Radiologic follow-up in all cases was undertaken to confirm extent of resection. Results: Seven patients were treated with MICs for complete surgical excision of BCMs during this time period. All patients had experienced at least one hemorrhage before presentation. Postoperatively, there were three instances of transient neurologic symptoms, all of which resolved at last follow-up. All seven patients experienced neurologic improvement after surgery, with four patients showing no deficits at last follow-up. Approach selection rationale and technical nuances are presented on a case-by-case basis. Conclusion: With carefully planned MIC approaches to BCMs presenting to the brainstem surface, excellent results may be achieved without the necessity of larger conventional craniotomies. We believe these nuances may be of use to others in treating these challenging lesions.