Retrosigmoid Approach and Hybrid Use of Endoscopy in CPA Tumors

The retrosigmoid (RS) approach is a safe multichannel avenue designed for surgical management of cerebellopontine angle (CPA) lesions. Thorough knowledge of the regional anatomy and expertise in microsurgical techniques are required to maintain the integrity of the neurovascular structure and achieve successful postoperative functional outcomes. The RS approach can be used alone or combined with the presigmoid-retrolabyrinthine approach to enhance surgical exposure and remove trans-compartmental or large petroclival tumors. While this adjunct offers anterolateral extension and shorter working avenues with less cerebellar retraction, it requires significant bone drilling and increases operative time and potential complications. The less invasive variant of the retrosigmoid intradural suprameatal approach (RESA) or the recent implementation of hybrid use of endoscopy has limited the need for such an extensive skull base bony exposure. The retrosigmoid (RS) approach and its variant represent valuable additions to the armamentarium of skull base surgery, allowing a smooth and less invasive direct access to CPA lesions with excellent clinical outcome.