Retractorless Mini-retrosigmoid Approach for Petroclival and Cerebellopontine Angle Tumors: Surgical Feasibility and Outcomes

Introduction: Petroclival and cerebellopontine angle (CPA) tumors present significant challenges in neurosurgery due to their proximity to critical neurovascular structures. Minimally invasive approaches are gaining traction for reducing length of stay (LOS) and postoperative complications while maximizing tumor resection and minimizing morbidity. The retractorless mini-retrosigmoid approach offers a targeted technique with reduced manipulation of adjacent structures. This study evaluates its safety and effectiveness, with particular attention to facial nerve outcomes.

Methods: A retrospective review was conducted on patients undergoing resection of petroclival and CPA tumors via the keyhole retractorless retrosigmoid approach between 2022 and July 2024. Patients with a minimum follow-up of 3 months were included. Data on demographics, intraoperative parameters, and postoperative outcomes were gathered from a prospective database.

Results: Ten patients met inclusion criteria (median age 59.5 years, range 41–89). Tumor pathology was meningioma in 70% and schwannoma in 30%. The median LOS was 2.5 days, with no readmissions. Gross total resection (GTR) was achieved in 90% of cases; one patient required near-total resection. Three cases required petrous apex drilling, and three underwent transcanalicular approaches for vestibular schwannomas. Preoperative modified Rankin Scale (mRS) scores ranged from 1 to 5, with 80% showing postoperative mRS improvement at 6 weeks and all patients demonstrating stable or improved mRS at 6 months. One patient experienced transient House-Brackmann (HB) grade 3 facial palsy, and one had persistent HB grade 3 facial palsy postoperatively. No CSF leaks, infections, hematomas, or pseudomeningoceles were observed. At a median follow-up of 9 months, no tumor recurrences were noted.

Conclusion : The retractorless mini-retrosigmoid approach is a safe and minimally invasive technique for resecting petroclival and CPA tumors, offering high rates of tumor control and low morbidity. This pilot study supports its feasibility, with promising early outcomes in facial nerve preservation and postoperative recovery.