Abstract
Brainstem cavernous malformations (BSCMs) are challenging cerebrovascular lesions that carry a high risk of hemorrhage and attendant disease morbidity.(1,2) Interpeduncular midbrain BSCMs are an uncommon subtype, with unique symptomatology and risk profile because of their deep location and intimate interrelatedness with numerous critical neurovascular structures, including posterior thalamoperforators, oculomotor nerves and nuclei, cerebral peduncles, and the reticular activating system.(3-5) A 13-mm interpeduncular BSCM was diagnosed in a patient who presented to an outside facility with left visual blurring. Surgical excision was initially deferred. The patient subsequently developed symptomatic hydrocephalus secondary to recurrent hemorrhage, prompting ventriculoperitoneal shunt placement followed by neurosurgical resection. A left orbitozygomatic craniotomy and transsylvian approach was performed. Wide interpeduncular fossa access was optimized through temporal lobe mobilization, left posterior communicating artery division, and thalamoperforator release. The superficial BSCM was accessed and immediately entered through pial presenting point, allowing internal de bulking and piecemeal gross total resection. Intact gliotic margins and a large developmental venous anomaly were visualized at the depth of the resection cavity. Postoperatively, the patient had a transient left oculomotor nerve palsy and depressed level of consciousness, which resolved on follow-up. Microsurgical resection is a feasible, safe, and effective strategy for treatment of symptomatic interpeduncular BSCMs. The patient provided informed consent.