Endoscopic nasopharyngectomy for salvage in nasopharyngeal carcinoma: a novel anatomic orientation.

ABSTRACT

OBJECTIVES/HYPOTHESIS: Nasopharyngectomy for residual/recurrent nasopharyngeal carcinoma (NPC) using an endoscopic technique is less invasive than traditional methods. Our objective was to identify the important anatomic landmarks so that the endoscopic surgeon can avoid injury to the internal carotid artery and perform a nasopharyngectomy safely. STUDY DESIGN: Anatomical study. METHODS: Transnasal endoscopic dissection was carried out on three fresh adult cadaver specimens (six sides) after arterial latex injection. Measurements were made in 50 adult skulls (100 sides), detailing the distances between orienting critical landmarks and the internal carotid canal (external aperture). RESULTS: Adequate exposure for endoscopic nasopharyngectomy is available by removing portions of the inferior turbinate, nasal septum, and medial pterygoid plate. Anatomy of the operative field (endoscopic view) is described. Orientating topical landmarks include posterior portions of the inferior turbinate and nasal septum, fossa of Rosenmuller, and the torus tubarius. The deep landmarks include medial pterygoid plate-posterior margin at the skull base, eustachian tube isthmus, foramen lacerum, and the longus capitis. All topical and deep landmarks were identified from the endoscopic point of view and their distances to the internal carotid canal (external aperture) were measured. CONCLUSIONS: This anatomic study provides novel orienting landmarks for endoscopic nasopharyngectomy. Surgeons can efficiently and safely deal with residual and/or recurrent NPC endoscopically.