A description of the anatomy of the glossopharyngeal nerve as encountered in transoral surgery.
To illustrate detailed anatomy of the extracranial portion of the glossopharyngeal nerve in the parapharyngeal space as encountered during transoral surgery.



Prospective cadaveric dissection. All dissections were performed transorally and confirmed with transcervical dissection.



Eight color-injected cadaveric heads (16 sides) were dissected to demonstrate the course and anatomy of the glossopharyngeal nerve. Conventional external dissections were performed to verify our anatomic measurements. Anatomical measurements of the glossopharyngeal nerve, including segments, branches in each segment, relationship with stylopharyngeus muscle, internal carotid artery, and pharyngeal branch of Vagus were recorded and analyzed.



The glossopharyngeal nerve was separated into three segments according to the relationship with the stylopharyngeus muscle. Total lengths of the glossopharyngeal nerve are 32.6 ± 3.1 (left side) and 30.6 ± 3.7 (right side) mm, respectively. The average number of branches in the upper, middle, and lower segments is 3 (range 1-3), 4 (range 2-4), and 3 (range 1-3), respectively. The total number of branches is 8 (range 6-9). The average diameter of the main trunk of the glossopharyngeal nerve is 1.2 ± 0.3 mm, and the average diameter of the lingual branch of the glossopharyngeal nerve is approximately 0.6 ± 0.2 mm. In 75% of cases, pharyngeal branch of Vagus crosses the glossopharyngeal nerve, whereas in 25% of cases it parallels the course of the glossopharyngeal nerve to form the pharyngeal nerve plexus to innervate the pharyngeal wall.



Understanding the precise and detailed anatomy of the glossopharyngeal nerve in the parapharyngeal space is important in transoral surgery for indications such as transoral robotic surgery or transoral laser microsurgery tumor resection, lingual tonsillectomy, glossopharyngeal neuralgia, glossopharyngeal nerve block, and internal carotid artery dissection.



N/A. Laryngoscope, 126:2010-2015, 2016.
Department of Otolaryngology Head and Neck Surgery, China-Japan Friendship Hospital, Chaoyang District, Beijing.|Department of Head and Neck Surgery, Shenmu County Hospital, Shanxi Province, People's Republic of China.|Veterans Affairs Pittsburgh Health System and UPMC Department of Otolaryngology/Head and Neck Surgery, University of Pittsburgh Medical Center, Eye and Ear Institute, Pittsburgh, Pennsylvania, U.S.A.|Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, U.S.A.
Chengyuan
C
Wang
Veterans Affairs Pittsburgh Health System and UPMC Department of Otolaryngology/Head and Neck Surgery, University of Pittsburgh Medical Center, Eye and Ear Institute, Pittsburgh, Pennsylvania, U.S.A.
Summit
S
Kundaria
Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, U.S.A.
Juan
J
Fernandez-Miranda
Veterans Affairs Pittsburgh Health System and UPMC Department of Otolaryngology/Head and Neck Surgery, University of Pittsburgh Medical Center, Eye and Ear Institute, Pittsburgh, Pennsylvania, U.S.A.
Umamaheswar
U
Duvvuri
D002102:Cadaver; D005930:Glossopharyngeal Nerve / Q000033:anatomy & histology*; D006801:Humans; D009055:Mouth; D010614:Pharynx; D011446:Prospective Studies; D013514:Surgical Procedures, Operative / Q000379:methods
Glossopharyngeal nerve; anatomy; parapharyngeal space; transoral surgery