title: Mediastinal surgery in connective tissue tunnels using flexible endoscopy.
abstract: BACKGROUND
  Mediastinal surgery most often is performed via a transthoracic or transabdominal approach; however, the pre- and paratracheal mediastinum can be readily accessed with a transcervical approach. The purpose of this study was to evaluate the feasibility, safety, and success rate of using a transcervical approach and flexible endoscopes to perform mediastinal surgery also in the retro- and paraesophageal mediastinum.
  
  
  METHODS
  Mediastinal operations on four live pigs and one human cadaver were performed using standard endoscopes through a small cervical incision. The procedure involved marking of four mediastinal lymph nodes using endoscopic ultrasound (EUS). The esophagus was dissected to the phrenoesophageal junction by creating connective tissue tunnels with balloon dilatation and low-pressure CO(2) insufflation. Heller myotomy was performed followed by sequential identification and removal of the marked nodes. Success rate of esophageal dissection to the diaphragm, Heller myotomy, directed mediastinal lymph node harvest, and complication rates were evaluated.
  
  
  RESULTS
  Dissection of the esophagus to the diaphragm was achieved in 100% of attempts. Distal esophageal myotomy was performed in all cases. Harvest of marked lymph nodes (ln) was successful in 100% of animals (16/16 ln) and cadavers (2/2 ln). One major complication was recorded in the pig group (tension pneumomediastinum).
  
  
  CONCLUSIONS
  The entire visceral mediastinum can be successfully accessed through a transcervical incision using flexible endoscopes. Directed lymph node harvest and esophageal myotomy is feasible with a high success rate. Connective tissue tunnels are safe, atraumatic, and a promising concept for targeted mediastinal exploration. With refinement in technology, this approach may be useful for a variety of mediastinal surgeries.
authors.affiliation: Legacy Health System, Portland, OR, USA, georg.spaun@gmail.com
authors.forename: G O
authors.initials: GO
authors.lastname: Spaun
authors.forename: C M
authors.initials: CM
authors.lastname: Dunst
authors.forename: D V
authors.initials: DV
authors.lastname: Martinec
authors.forename: B N
authors.initials: BN
authors.lastname: Arnold
authors.forename: M
authors.initials: M
authors.lastname: Owens
authors.forename: L L
authors.initials: LL
authors.lastname: Swanstrom
mesh_terms: D000818:Animals; D002102:Cadaver; D002404:Catheterization; D003238:Connective Tissue; D019160:Endosonography; D004947:Esophagus / Q000601:surgery; D005240:Feasibility Studies; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D020707:Mediastinoscopes; D008481:Mediastinoscopy / Q000295:instrumentation / Q000379:methods*; D008482:Mediastinum / Q000601:surgery*; D013552:Swine; D016896:Treatment Outcome