We used a paramedian, infratentorial-supracerebellar, transcollicular approach to resect 6 intrinsic midbrain cavernous malformations. The route of access to the lesions was designed to minimize the anatomic and functional damage to the surrounding structures. Access was through one superior colliculus in 2 cases, through one inferior colliculus in 2 cases, and through the superior and inferior colliculi of one side in 2 cases. All 6 lesions were completely removed; the preoperative ocular symptoms improved in 4 of these 6 patients and did not change in 2. The neurological deficits except ocular symptoms improved in 2 patients. No recurrence of bleeding was observed during the follow-up period (mean 52 months).
We conclude that the paramedian, infratentorial-supracerebellar, transcollicular approach permits safe removal of intrinsic midbrain cavernous malformations. Resection of the superior or inferior colliculus, or both, on one side appears to be neurologically well tolerated.