Exploration of anatomical landmarks for performing an endoscopic transoral nasopharyngectomy

Abstract

Background Performing a nasopharyngectomy via a transoral approach has been reported; however, defining landmarks to facilitate this approach has not been addressed. This study aims to explore anatomical landmarks to aid in performing a nasopharyngectomy via the transoral corridor. Methods An endoscopic transoral nasopharyngectomy was performed on six cadaveric specimens (12 sides). Related anatomical landmarks were defined, and the strategy to preserve the parapharyngeal internal carotid artery (pICA) was explored. Results An endoscopic transoral nasopharyngectomy was successfully achieved in all 12 sides. Utilizing the pterygoid hamulus as a landmark, the cartilaginous ET and attachments could be adequately exposed. Identification of the pICA is a prerequisite prior to Eustachian tube (ET) transection. The sphenoidal spine and the petrotympanic fissure could be sufficiently revealed in all 12 sides, which aided in transection of the cartilaginous ET without pICA injury. The ET and the prevertebral contents could be adequately removed via the transoral corridor. Conclusion The pterygoid hamulus, sphenoidal spine and petrotympanic fissure serve as reliable landmarks for performing a transoral nasopharyngectomy. Identification of the pICA is a prerequisite prior to transection of the ET to avoid pICA injury.

Maximal exposure of the parapharyngeal internal carotid artery via transnasal and transoral corridors

“…Technical details of a transoral approach for exposure of the pICA, has been previously described 8,14–16 . An incision was performed at the lateral oropharyngeal wall paramedial to the pterygo‐mandibular raphe.…”

Endoscopic endonasal combined transoral medial approach to the nasopharynx, parapharyngeal space, and jugular foramen

“…Endoscopic salvage surgery for recurrent NPC is widely accepted and recognized 6,7 . Previous studies have also suggested a transoral transpalatal approach that can avoid dealing with the pterygoid process, and thus, may help with dissection and protect the parapharyngeal internal carotid artery (ICA) 8,9 . The main surgery for early staged recurrent NPC is nasopharyngectomy around the ET.…”

“…6,7 Previous studies have also suggested a transoral transpalatal approach that can avoid dealing with the pterygoid process, and thus, may help with dissection and protect the parapharyngeal internal carotid artery (ICA). 8,9 The main surgery for early staged recurrent NPC is nasopharyngectomy around the ET. The conventional endoscopic endonasal surgery often requires a transpterygoid approach to expose the structure around the ET, which is traumatic and time consuming, and identification of the ICA is indefinite.…”

Endoscopic transoral approach to the lateral poststyloid space

“…[12][13][14][15] With the increased usage of a transoral approach for extirpation of tumors arising in the parapharyngeal space, indications have been gradually expanded. [15][16][17][18] For example, the transoral corridor has been used for resection of tumors arising from the retrostyloid compartment. 14 Moreover, for tumors arising from the parapharyngeal space with an extension into the jugular foramen region or the posterior cranial fossae, the transoral corridor can also provide a rational exposure for lesion extirpation.…”

“…In the past two decades, a transoral approach for extirpation of tumors arising from the parapharyngeal space has been gradually accepted and applied in various skull base centers 12–15 . With the increased usage of a transoral approach for extirpation of tumors arising in the parapharyngeal space, indications have been gradually expanded 15–18 . For example, the transoral corridor has been used for resection of tumors arising from the retrostyloid compartment 14 .…”