SURG-97. Minimally invasive approach to metastatic posterior fossa tumors with tubular retraction: A single institutional experience

Abstract INTRODUCTION Posterior fossa brain metastases are associated with significant morbidity and often require surgical resection due to the high risk of obstructive hydrocephalus. Minimally invasive keyhole craniotomy (MIKC) using a tubular retractor offers potential advantages over traditional open techniques, including smaller incisions and lower complication rates. However, outcomes of MIKC specifically for cerebellar metastases remain understudied. Objective: To evaluate the outcomes of MIKC for metastatic posterior fossa tumors and determine whether this approach provides comparable extent of resection and local control with fewer complications and faster recovery compared to open surgery. METHODS A retrospective review was conducted of patients who underwent MIKC for resection of posterior fossa metastatic tumors at Ochsner Health between 2014 and 2025. RESULTS Thirty patients (17 male, 13 female; mean age 65) underwent MIKC using tubular retractors. Mean operative time was 141 minutes (median 144, range 74–215) with mean estimated blood loss of 76 cc (median 75cc). Mean preop tumor volume was 12.7 cm3, and mean craniotomy diameter was 2.4 cm. Mean ICU stay was 2.0 days (median 1 day), and mean total hospital stay was 5.2 days (median 3 days). Gross total resection (GTR) was achieved in 27 patients (90%). Intraoperative Cesium brachytherapy was delivered in 8 cases (reported elsewhere), while 15 patients underwent stereotactic radiosurgery at a mean of 39 days postop. Local recurrence or new brain metastases occurred in 9 patients (30%) at a mean imaging follow up time of 285 days. By Kaplan Meier analysis, median time to local recurrence was 474 days. Mean overall survival was 318 days (median 161 days). Post-operative complications were infrequent and included CSF leak and pseudomeningocele, each in one patient. CONCLUSION Minimally invasive tubular resection of cerebellar metastases is a safe and effective approach, offering high GTR rates and low complication rates.