One- vs two-burr-hole technique for combined endoscopic third ventriculostomy and pineal region biopsy: Volumetric analysis of brain at risk

Abstract

BACKGROUND: Pineal region tumors are associated with the ventricular system. Endoscopic third ventriculostomy (ETV) is often performed at the same time as tumor biopsy. OBJECTIVE: To investigate the volume of brain possibly undergoing injury and forniceal stretching during ETV and tumor biopsy. METHODS: We performed a retrospective review of preoperative magnetic resonance imagings (MRIs) and computed tomography (CTs) of patients with pineal region masses and used volumetric image-guided navigation to simulate a 1-burr-hole vs a 2-burr-hole approach through the brain parenchyma. We compared the volumes of parenchyma and fornix at the risk of injury. RESULTS: The ideal entry point for ETV using 2 burr holes was a mean±standard deviation (SD) of 25.8±6mmfromthe midline and 11.4±9mmbehind the coronal suture. The ideal entry point using 2 burr holes for tumor biopsy was 25.7 ±8 mm from the midline and 53.7 ±14 mm anterior to the coronal suture. With 1 burr hole, the mean ±SD volume of brain parenchyma at riskwas 852±440mm3. The volume of brain parenchyma at riskwith 2 burr holes was 2159±474mm3 (P