2025 Proffered Presentations
S318: A COMPARATIVE ANALYSIS OF MANEUVERABILITY AT THE INFRATEMPORAL FOSSA: ADVANTAGES AND DRAWBACKS OF THE ENDOSCOPIC CONTRALATERAL TRANSMAXILLARY-TRANSPTERYGOID AND FISCH C APPROACHES
Alejandra Rodas, MD; Leonardo Tariciotti, MD; Jackson R Vuncannon, MD; Youssef M Zohdy, MD; Juan M Revuelta-Barbero; Roberto M Soriano, MD; Edoardo Porto, MD; Biren K Patel, MD; Emily Barrow, MD; Tomas Garzon-Muvdi, MD; Gustavo Pradilla, MD; C. Arturo Solares, MD; Emory University
Introduction: Surgical control of lesions involving the infratemporal fossa and lateral pharyngeal space continues to be a challenge. The transmaxillary transpterygoid endoscopic endonasal approach has shown to be a feasible alternative for tumors such as nasopharyngeal carcinomas or angiofibromas with infratemporal fossa and parapharyngeal extension; yet maneuverability of paramedian structures depends on various corridor constraints, including the hard palate inferiorly, the maxillectomy’s border anteriorly, and the tissue bulk inflicted by the masticatory and parapharyngeal muscles. When the endoscopic endonasal approach is not feasible due to the tumor’s infiltrative nature, alternatives must be considered. The Fisch type C approach allows access to the infratemporal fossa, through a corridor that bypasses many of these constraints. An objective analysis of maneuverability comparing both techniques can aid preoperative surgical planning.
Method: Four embalmed human cadaveric specimens were used for anatomical dissection. An endoscopic endonasal transmaxillary-transpterygoid approach and Fisch type C approach were fashioned on each specimen. For the endonasal transmaxillary-transpterygoid approach, a posterior septectomy was performed to allow access from both nostrils and reduce instrument swording. Access to the infratemporal fossa through the infratemporal corridor required downward retraction of the joint capsule. Using imaging-based navigation, coordinate points were collected to assess maneuverability at foramen ovale and the most medial and lateral aspect of the eustachian tube.
Results: A transpterygoid and infratemporal corridor were dissected bilaterally on each specimen, exposing the eustachian tube in its entirety. The eustachian tube’s length from the middle ear to its opening at the nasopharynx was measured. Through the infratemporal approach, the whole length of the eustachian tube could be maneuvered, contrary to the transpterygoid approach in which the lateral pterygoid muscle prevented mobility at the most lateral aspect. In addition, vertical and horizontal angles of attack were measured for V3 at foramen ovale, evidencing improved maneuverability through the infratemporal corridor. The volume of each corridor was assessed through navigation coordinates. For the Fisch type C approach, the volume was assessed twice to show the percentual increase after resection of the joint’s articular disc.
Conclusion: The endoscopic endonasal approach is a feasible technique for surgical management of lesions with extension to the infratemporal fossa and parapharyngeal space. However, maneuverability of paramedian structures adds to the complexity of the surgery and may impact the possibility of gross-total-resection. The Fisch type C approach provides a different perspective with enhanced maneuverability at the lateral aspect of the eustachian tube; yet one must consider the functional loss this technique produces on conductive hearing.
