Endoscope-assisted microsurgical retrosigmoid approach to the lateral posterior fossa: Cadaveric model and a review of literature

Abstract

Background: The advancement of endoscopic techniques in the past decade has improved the surgical management of cerebellopontine angle (CPA) tumors. Endoscope-assisted microsurgery improves the ability to evaluate the extent of resection, achieve safe tumor resection and reduce the risk of surgery-related morbidity. Methods: In this study, we used a cadaveric model to demonstrate a step by step endoscope-assisted microsurgery of the retrosigmoid approach to the lateral posterior fossa. Results: Retrosigmoid craniotomies were performed on four latex-injected cadaver heads (eight CPAs). Microsurgical exposures were performed to identify neurovascular structures in each segment. 0° and 30° rigid endoscope lenses were subsequently introduced into each corridor and views were compared in this manner. The endoscopic images were compared with the standard microscopic views to determine the degree of visualization with each technique. In each case, better visualization was provided by both the 0° and 30° endoscope lenses. Endoscopic views frequently clarified neurovascular relationships in obscured anatomic regions. Conclusion: Endoscope-assisted microsurgery could allow better visualization of various regions of the posterior fossa. Surgical planning for posterior fossa lesions should include consideration of this combined approach.

Commentary: Microsurgical Endoscopy-Assisted Decompression of the Trigeminal Nerve Impingement: 2-Dimensional Operative Video

“…Intraoperative endoscopic-assisted microsurgical approaches to the lateral posterior fossa have been well-described in numerous lesions of the cerebellopontine angle. [5][6][7][8] Potential advantages of incorporating the angled endoscope to the narrow surgical corridors often encountered in the lateral posterior fossa include panoramic visualization, angled lenses, and delivery of illumination more directly into the surgical field. Traditional operative microscopy of the lateral posterior fossa is often limited to the dorsal surface of the neurovascular structures, but the endoscope allows for visualization of Meckel cave, the subchiasmatic cistern, and potentially across midline.…”