Endoscopic endonasal transpterygoid approaches: Anatomical landmarks for planning the surgical corridor

TLDR

Endoscopic endonasal transpterygoid approaches (EETA) rely on sinonasal pneumatization to access middle and posterior skull base lesions, yet the complex anatomy makes corridor planning difficult. The study aimed to define anatomical landmarks for preoperative planning of EETAs. High‑resolution maxillofacial CT scans were analyzed with cephalometric measurements to quantify distances from the midline to the vidian canal and from the vidian canal to the foramen rotundum, and a novel classification of EETA variants was developed. Measured average distances were 12.78 mm (midline to vidian canal), 5.6 mm (horizontal vidian canal to foramen rotundum), and 6.22 mm (vertical), and the identified landmarks and classification proved useful for accurate surgical corridor planning.

Abstract

Endoscopic endonasal transpterygoid approaches (EETA) use the pneumatization of the sinonasal corridor to control lesions of the middle and posterior skull base. These surgical areas are complex and the required surgical corridors are difficult to predict.Define anatomical landmarks for the preoperative planning of EETAs.Anatomical study.We reviewed images from high-resolution maxillofacial CT scans with (0.6-mm axial slice acquisition). Cephalometric measurements were obtained using Kodak Carestream Image Software (Rochester, NY).Average distance from midline to the vidian canal was 12.78 mm (range 9.4-15.8 mm). Average horizontal distance from the vidian canal to the foramen rotundum was 5.6 mm (range 2.8-11.5 mm). Average vertical distance from the vidian canal to the foramen rotundum was 6.22 mm (range 4.3-9.3 mm). These landmarks are consequential during the preoperative planning of the surgical corridor. To facilitate communication, we classified EETAs as: A) Partial removal of the pterygoid plates (transposition of temporo-parietal fascia); B) removal of anteromedial aspect of the pterygoid process (lesions involving the lateral recess of the sphenoid sinus); C) involves dissecting the vidian nerve to control the petrous ICA and removing the pterygoid plates base to reach the petrous apex, Meckel's cave, or cavernous sinus; D) variable removal of the pterygoid plates to access the infratemporal fossa; and E) removal of pterygoid process and medial third of the Eustachian tube to expose the nasopharynx.Our novel classification and landmarks system helps to understand the anatomy of this complex area and to accurately plan the EETA.