The Retrosigmoid Approach: Workhorse for Petroclival Meningioma Surgery

BACKGROUND: Petroclival meningiomas (PCMs) are technically challenging lesions. We retrospectively analyzed our experience with retrosigmoid approach between 2009 and 2015 in 17 patients with PCM to evaluate changes in management strategy. In this study, we evaluated the possible risk factors and challenges for unfavorable clinical outcomes with retrosigmoid approach. MATERIALS AND METHODS: A total of nine patients (53%) of PCM were treated through the retrosigmoid approach in Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow. The patients received postoperative neurological and radiological follow-up. The primary difficulty in complete resection and outcomes including postoperative neurological deficits were evaluated, and all potential risk factors were assessed. RESULTS: The mean follow-up time was 24 months. The maximum diameter of the tumors ranged from 2.0 cm to 6.8 cm (mean, 3.8 cm). Gross total resection (Simpson Grade II) was achieved in 6 (66%) patients, subtotal resection (Simpson Grade III) in 3 (33%). Two patients (22%) had new neurological deficits or worsening of preexisting deficits. No patient died after surgery. Within the follow-up period, there was no radiographic recurrence in patients with Simpson Grade II excision. Postoperative radiosurgery was administered to three patients who had residual tumors, and no further progression was found in them. CONCLUSIONS: Tumor characteristics played a critical role in identifying postoperative functional status. The retrosigmoid approach is suitable for treatment of majority of PCMs. It offers Simpson Grade II excision if the main part of the tumor is located in the posterior fossa in the cerebellopontine angle and the lower clivus, and only a minor part of the tumor extends to middle fossa or the posterior wall of the cavernous sinus. With incising tentorium or suprameatal extensension middle fossa extension can also be removed. Overall retrosigmoid approach provides a low degree of surgical difficulty and a low complication rate.