Accessing the Parapharyngeal Space and Infratemporal Fossa Skull Base Using Robotic Surgery: An Anatomic Descriptions and Preliminary Clinical Series

Objectives: The purposes of this study are to describe the parapharyngeal space and infratemporal fossa anatomy from a transoral perspective and discuss how robotic surgery may be applied to resect tumors within the infratemporal fossa. Study Design: A retrospective case series at a tertiary academic center. Methods: The da Vinci surgical robot (Si) was applied for off-label use to resect four skull base tumors. The pathological diagnosis was two pleomorphic adenomas in the parapharyngeal space—one pleomorphic adenoma in the infratemporal fossa, and one metastatic papillary thyroid cancer node in the high retropharyngeal nodal basin. A transpalatal approach was used to access the infratemporal fossa and retropharynx. Lateral pharyngotomies were performed to access the parapharyngeal spaces. Results: Relevant anatomy related to the transoral robotic surgery (TORS) approach and dissection along the carotid into the infratemporal fossa are discussed. Our four cases are used to illustrate the clinical applicability of this anatomy and the TORS approach for skull base tumors. All four patients had complete resection of tumor confirmed by postoperative imaging. There were no intraoperative arterial injuries. One patient experienced a transient episode of 1-mm ptosis that resolved spontaneously. Patients had normal swallowing function within 5 days following surgery. There were no recurrences within short follow-up time (8–14 months). Conclusions: Knowledge of the parapharyngeal space and infratemporal fossa anatomy allows for safe resection of tumors in these spaces using transoral robotic surgery. Future advances in technology will allow better access to additional portions of the skull base.