The Transnasal Transpterygoid Approach for Tumors of the Central Skull Base

Introduction: Many different descriptions have been published on the feasibility of the transnasal endoscopic approach for central skull base lesions in recent years. Only a few of them have dealt with the impact on tumor surgery on the outcome. A frequently used classification of these corridor approaches distinguishes the transcribriform, the expanded transsphenoidal, and the transclival approaches. Based on our experience, we would like to add the transnasal transpterygoid approach (TTP) to this classification.

Methods: Starting with a sphenoethmoidectomy, as described elsewhere, the maxillary sinus is widely opened to expose the back wall of this sinus. The latter is removed starting from the sphenopalatine foramen downward and laterally. The maxillary artery must be frequently ligated. Identifying the infraorbital nerve in the orbital floor and enlarging the sphenoid laterally allow exposure of the foramen rotundum at the cavernous sinus. Dissecting more laterally, the foramen ovale can be identified. Drilling the medial pterygoid process from medially to laterally exposes the sphenopalatine ganglion and its associated nerve.

Results: During the last 5 years, 32 patients with skull base tumors underwent TTP. In 17 of 32 (53%), only gross removal or debulking of tumor masses was performed. In the remaining 15, a radical tumor removal was achieved. For TTP, extra long instrumentation and image guidance are mandatory.

Discussion: TTP is an additional type of transnasal endoscopic corridor surgery to the central skull base. Similar to the other endoscopic approaches, the effectiveness of this approach needs to be proven by more data.