Transdural Cisternotomy in the Extended Middle Fossa Approach.

Dolenc's pretemporal transcavernous approach and Kawase's s anterior transpetrosal approach are the two primary extradural middle cranial fossa approaches (EMFAs) to the central skullbase. The extended extradural phase of the surgery may potentially result in temporal lobe edema, compromising the surgical exposure and sometimes a postoperative temporal lobe venous infarction. The authors describe an alternative technique of cerebrospinal fluid (CSF) drainage called "transdural cisternotomy" in EMFA. In this, CSF is released from the chiasmatic cistern during the extradural stage of surgery. Two illustrative cases are shown, a case of petroclival meningioma and a petroclival intradural chordoma. Both patients underwent gross total tumor resection with good long-term outcome. Transdural cisternotomy was greatly beneficial in both the cases. Based on our experience with several such cases, the transdural cisternotomy described here is an easy, reproducible, and effective method of brain relaxation in EMFAs.