We describe our surgical posterior transpetrosal technique, particularly the transcrusal variant for lesions involving the upper and middle clivus, petroclival regions, and lesions that involve both the posterior and middle fossae.METHODS
An outline of the posterior transpetrosal technique involved, particularly the transcrusal variant, is described. Important superficial landmarks are identified, and a radical mastoidectomy is performed. The antrum is identified and entered, and, upon completion of the mastoidectomy and when Trautman's triangle is defined, the temporal and suboccipital craniotomies are completed. After bone flap elevation, dura opening, and incision along the middle fossa dura, the superior petrosal sinus is ligated and cut. Tentorium cut completion is at the incisura posterior to the trochlear nerve. Watertight dural closure and standard flap replacement and skin closure complete the technique.RESULTS
Clival exposure and the degree of temporal bone resection increase. Operative freedom also increases with increased temporal bone resection, especially when going from the retrolabyrinthine to transcrusal variants. Little is gained in terms of operative freedom and exposure of the clivus with resection of additional temporal bone beyond that of the transcrusal variant, and resection carries the cost of increasing morbidity, especially with respect to VIIth and VIIIth nerve function.CONCLUSION
The posterior transpetrosal approach and the transcrusal variant provide a lateral operative corridor to lesions of the upper and middle clivus. The transcrusal variant provides increased exposure and operative freedom similar to that provided by the transcochlear approach while minimizing cranial nerve morbidity.