title: Applied anatomy of a new approach of endoscopic technique in thyroid gland surgery.
abstract: OBJECTIVE
  To explore the feasibility and safety of transtracheal assisted sublingual approach to totally endoscopic thyroidectomy by studying the anatomical approach and adjacent structures.
  
  
  METHODS
  A total of 5 embalmed adult cadavers from Chengdu Medical College were dissected layer by layer in the cervical region, pharyngeal region, and mandible region, according to transtracheal assisted sublingual approach that was verified from the anatomical approach and planes. A total of 15 embalmed adult cadavers were dissected by arterial vascular casting technique, imaging scanning technique, and thin layer cryotomy. Then the vessel and anatomical structures of thyroid surgical region were analyzed qualitatively and quantitatively. Three-dimensional visualization of larynx artery was reconstructed by Autodesk 3ds Max 2010(32). Transtracheal assisted sublingual approach for totally endoscopic thyroidectomy was simulated on 5 embalmed adult cadavers.
  
  
  RESULTS
  The sublingual observed access was located in the middle of sublingual region. The geniohyoid muscle, mylohyoid seam, and submental triangle were divided in turn in the middle to reach the plane under the plastima muscles. Superficial cervical fascia, anterior body of hyoid bone, and infrahyoid muscles were passed in sequence to reach thyroid gland surgical region. The transtracheal operational access was placed from the cavitas oris propria, isthmus faucium, subepiglottic region, laryngeal pharynx, and intermediate laryngeal cavit, and then passed from the top down in order to reach pars cervicalis tracheae where a sagittal incision was made in the anterior wall of cartilagines tracheales to reach a ascertained surgical region.
  
  
  CONCLUSIONS
  Transtracheal assisted sublingual approach to totally endoscopic thyroidectomy is anatomically feasible and safe and can be useful in thyroid gland surgery.
authors.affiliation: Department of Clinical Medicine, Basic Medical School, Chengdu Medical College, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Yong-jun
authors.initials: YJ
authors.lastname: Xie
authors.forename: Yi-quan
authors.initials: YQ
authors.lastname: Xu
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Xing-guo
authors.initials: XG
authors.lastname: Liu
mesh_terms: D000328:Adult; D004724:Endoscopy / Q000379:methods; D006801:Humans; D009060:Mouth Floor / Q000033:anatomy & histology*; D010280:Parathyroid Glands / Q000033:anatomy & histology; D013965:Thyroidectomy / Q000379:methods*