Lorenzo Giammattei1, Daniele Starnoni1, David Peters1,2, Daniel Ronconi3, Breno Camara3, Mercy George4, Giulia Cossu1,5, Mahmoud Messerer1,5, Roy T Daniel6,7,8. 1. Department of Neurosurgery, Lausanne University Hospital, Lausanne, Switzerland. 2. Carolina Neurosurgery & Spine Associates, Charlotte, NC, USA. 3. Neurosurgery Department, Metropolitan Hospital Don José Maria Pires, Jõao Pessoa, Paraiba, Brazil. 4. Department of Otorhinolaryngology and Head and Neck Surgery, Lausanne University Hospital, Lausanne, Switzerland. 5. Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland. 6. Department of Neurosurgery, Lausanne University Hospital, Lausanne, Switzerland. roy.daniel@chuv.ch. 7. Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland. roy.daniel@chuv.ch. 8. Lukas Lundin and Family Brain Tumor Research Center, Lausanne, Switzerland. roy.daniel@chuv.ch.
Abstract
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.
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.