Extended Endoscopic Endonasal Transclival Approach for Tumors of Petroclival Region: Preliminary Experience

Background Petroclival tumors remain a surgical challenge. Classically, the retrosigmoid or transpetrosal approaches has been used to reach such tumors, based on the rule to avoid crossing vessels and cranial nerves. Recently, the endoscopic endonasal approach (EEA) has been “expanded” to the petroclival region, as an alternative minimally invasive way for well-selected type of tumors.

Methods We present seven cases of complex petroclival lesions treated via the EEA alone or as a second step following a classical approach. Two patients presented a large and symptomatic epidermoid cysts located in the ventrolateral brain stem cisterns with cerebellopontine angle extension. One patient harbored a cholesterinic granuloma of the petrous apex. The remaining four patients harbored sfenopetroclival meningiomas treated with combined fronto-orbitozygatic, or posterior transpetrosal or retrosigmoid suboccipital approaches supplemented by EEA.

Results Complete tumor removal was obtained in patients harboring epidermoid cysts, cholesterinic granuloma, and one meningioma. In the other older and/or more compromised patients, EEA was use with the aim of brain stem decompression. Only one patient presented cerebrospinal fluid leakage after surgery treated by seriate office-based endoscopic blood patches and injections of fibrin glue. No others threatening complications occurred after surgery, and the length of hospitalization was less than 10 days.

Conclusion In comparison to antero- or posterolateral skull base approaches, the transclival endoscopic endonasal approach allows direct access to the petroclival region without unnecessary manipulation of neurovascular structures at the cerebellopontine angle. Samii and Tatagiba popularized the “reverse” Kawase’s approach, this can be defined as the anterior “reverse” Kawase’s approach. In our preliminary experience, the EEA could represent an alternative minimally invasive approach for tumors with prevalent extension anterior and toward the midline, for cystic lesions and soft tumors such as epidermoid cysts. However, the skull base surgeon has to master all the possible routes for petroclival region to select the more appropriate one according to the surgical objective, the tumor characteristics, and the patient’s medical status because quite often we are facing very large and encasing tumors.