2026 Poster Presentations
P309: FASCIAL PLANE ORIENTED ENDOSCOPIC NASOPHARYNGECTOMY FOR NASOPHARYNGEAL CANCERS INVADING PARAPHARYNGEAL SPACE : PROOF CONCEPT, A CADAVERIC STUDY.
Sung-Woo Cho1; Minju Kim2; Dongyoug Kim3; Tae-Bin Won3; 1Seoul National University Bundang Hospital; 2National Medical Center; 3Seoul National University Hospital
Objective: To describe the surgical anatomy, fascial relationships, and procedural steps for fascial plane–oriented endoscopic nasopharyngectomy in cases of nasopharyngeal carcinoma with parapharyngeal space invasion, and to propose a classification system based on fascial boundaries.
Methods: Cadaveric heads underwent stepwise endoscopic nasopharyngectomy using a four-hand binostril transpterygoid approach. Key anatomical landmarks, fascial layers, and surgical corridors were documented.
Result: Fascial structures identified included the tensor vascular styloid fascia (TVSF), stylopharyngeal fascia (SPF), interpterygoid fascia, longus capitjs muscle fascia, and the fascial layer covering the parapharyngeal internal carotid artery (ppICA). Three fascial plane–based types of endoscopic nasopharyngectomy were proposed. Type A preserves the TVSF and resects up to the SPF–longus capitis fascia junction, suitable for limited parapharyngeal invasion. Type B involves resection lateral to the TVSF, removing the Eustachian tube, levator and tensor veli palatini, and parapharyngeal fat pad, while preserving the interpterygoid fascia, for tumors without infratemporal fossa involvement. Type C includes removal of the interpterygoid fascia (optionally V3), often via a combined Caldwell– Luc approach, for tumors with infratemporal fossa extension. Identification of the intersection between the stylopharyngeal fascia and the longus capitis muscle fascia was critical for defining the deep margin and avoiding ppICA injury.
Conclusion: Fascial plane–oriented endoscopic nasopharyngectomy provides a structured anatomical framework for safe and oncologically sound resection of nasopharyngeal carcinoma with parapharyngeal extension. The proposed classification, based on the extent of resection relative to fascial boundaries, may aid surgical planning and warrants validation in clinical cohorts.