title: Submucosal territory of the direct lymphatic drainage system to the thoracic duct in the human esophagus.
abstract: OBJECTIVE
  To investigate how large submucosal drainage territory extends in lymphatic drainage vessels of the esophagus with and without nodal delay and which morphologies are shown when passing through the muscularis propria.
  
  
  METHODS
  Submucosal territories of the 22 highly selected direct drainage vessels of 17 esophagi were histologically examined using transverse or sagittal serial sections. Afferent vessels from the esophagus to the subcarinal (6 esophagi) and para-esophageal (5 esophagi) nodes were also examined to identify their courses and drainage territories.
  
  
  RESULTS
  We found the direct drainage vessel from the esophagus in 17 of 75 cadavers macroscopically (22.7%). A single submucosal drainage unit gave off 1-3 thick drainage vessels passing through a complete muscle gap of the 2 muscular layers. The unit extended longitudinally for >40 mm but was restricted to the right and/or dorsal quadrants of the esophagus. In contrast, drainage routes with a nodal relay originated from the intermuscular area, except 1 case when the adjacent or concomitant esophageal artery and vein provided the complete muscle gap.
  
  
  CONCLUSIONS
  Due to the extended longitudinal but restricted transverse territory of the direct drainage system without a nodal relay and because of the suggested much more frequent occurrence in patients than in cadavers, when superficial carcinoma is found in the dorsal and/or right quadrants of the esophagus, we recommend detailed presurgical investigations of cervical nodes. In contrast, afferents from the esophagus to the first regional node usually seemed to be less responsible for early nodal metastasis than the direct drainage route because of their intermuscular origins.
authors.affiliation: Department of Surgery II, Kochi Medical School, Kochi, Japan.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Kuge
authors.forename: Gen
authors.initials: G
authors.lastname: Murakami
authors.forename: Shunji
authors.initials: S
authors.lastname: Mizobuchi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hata
authors.forename: Takashi
authors.initials: T
authors.lastname: Aikou
authors.forename: Shiro
authors.initials: S
authors.lastname: Sasaguri
mesh_terms: D004947:Esophagus / Q000033:anatomy & histology*; D006801:Humans; D008198:Lymph Nodes / Q000033:anatomy & histology; D008208:Lymphatic System / Q000033:anatomy & histology* / Q000648:ultrastructure; D009130:Muscle, Smooth / Q000000981:diagnostic imaging; D013897:Thoracic Duct / Q000033:anatomy & histology*; D014463:Ultrasonography