Combined Kawase-pretemporal transcavernous approach for resection of ventrolateral pontine and anteromedial temporal cavernous malformations.

BACKGROUND: Brainstem cavernous malformations (CMs) account for approximately 20% of all cerebral CMs and are among the most technically challenging neurosurgical lesions. Most arise within the pons, where dense nuclei and long tracts make even small hemorrhages clinically significant. Recurrent hemorrhage leads to cumulative neurological morbidity and necessitates surgery. Although stereotactic radiosurgery has been proposed for selected cases, its efficacy in preventing rebleeding remains uncertain, and the risk of radiation injury to eloquent brainstem tissue limits its role. Safe microsurgical management of ventrolateral pontine CMs requires optimization of the operative corridor. The Kawase anterior petrosectomy provides an extradural route to the ventrolateral pons but is constrained by limited working angles and restricted pretrigeminal exposure. Pretemporal transcavernous augmentation, achieved through interdural dissection of the lateral cavernous sinus wall (without entry into the venous compartment), mobilization of the trigeminal nerve, and exposure of Kawase's rhomboid, expands the corridor, improves visualization of the pretrigeminal safe entry zone, and preserves critical neurovascular structures. CASE DESCRIPTION: We report a 50-year-old male with progressive left ventrolateral pontine CM, resected through a combined Kawase-pretemporal transcavernous approach with simultaneous removal of an ipsilateral anteromedial temporal CM. Gross-total resection of both lesions was achieved without new neurological deficits, with postoperative imaging confirming complete removal and clinical stability at 2.5-year follow-up. CONCLUSION: This operative video demonstrates that pretemporal transcavernous augmentation expands the corridor and working angle to the ventrolateral pons beyond standard limitations, enabling safe management of multiple CMs in anatomically distinct locations through a single skull base approach.