Tentorial peeling during combined petrosal approach: a cadaveric dissection

Background The combined petrosal approach is an excellent method to access the petroclival region but has the inherent risk of injury to the temporal lobe and Vein of Labbé. Tentorial peeling has the potential to largely eliminate these risks during the classic combined transpetrosal approach. Methods Anatomical dissection of three adult injected non-formalin fixed cadaveric heads was performed. Combined petrosal approach with tentorial peeling was completed. A tentorial incision just superior and parallel to the superior petrosal sinus was made to enable peeling of the tentorium into two layers, the posterior fossa tentorial leaf (PFTL), and the temporal tentorial leaf (TTL). Results Tentorial peeling clearly exposed the continuity between the temporal dura and the TTL as well as the continuity between the presigmoid dura and the PFTL. This enabled the creation of a large dural flap extending to the tentorial incisura, providing wide access to the petroclival region without any exposure of the temporal lobe and/or basal temporal veins. Techniques to create the dural flap without trochlear nerve injury were also explored. Conclusion The technique of tentorial peeling into two distinct layers has the potential to reduce the morbidity associated with temporal lobe retraction and venous injury. Further cadaveric studies and surgical case series are needed to validate this important surgical nuance in transpetrosal approaches.