Operative results of keyhole supracerebellar-infratentorial approach to the pineal region.

The supracerebellar-infratentorial approach to the pineal region is typically accomplished with a craniotomy that extends to at least the rim of the foramen magnum. Minimally invasive techniques that limit the inferior extent of the craniotomy have been described for this approach but, to our knowledge, no operative results have been published demonstrating the feasibility and safety of such techniques. We present a series of patients who underwent surgical resection of pineal region lesions using the minimally invasive method at our institution. Clinical, radiologic, and operative data were prospectively collected on patients treated for lesions of the pineal region by the senior author from January 2012 to July 2014. Seven patients were identified. The sitting position was employed in each patient. Keyhole craniotomies were limited to a maximum diameter of 2.5 cm. Adequate working corridors were attained, and in no patient was resection limited by the exposure. No neurological or systemic complications were seen in the perioperative and early follow-up periods. In this feasibility study, we demonstrate that it is not necessary to extend a craniotomy inferiorly to the rim of the foramen magnum in order to gain access to the pineal region via relaxation of the cerebellum. The same surgical goals can be safely accomplished with a smaller craniotomy.