title: Chemically assisted submucosal injection facilitates endoscopic submucosal dissection of gastric neoplasms.
abstract: OBJECTIVE
  A randomized in vivo animal study previously demonstrated that topical injection of mesna solution (sodium-2-mercaptoethanesulfonate) chemically softened submucosal connective tissues and facilitated mechanical dissection of the submucosal tissue plane. The present study evaluated the technical feasibility and safety of chemically assisted endoscopic submucosal dissection (CA-ESD) using mesna in 20 consecutive patients who underwent endoscopic excision of gastric neoplasm.
  
  
  METHODS
  Following the margination of the lesion with a mucosal circumcision, 4 - 12 mL of 10 % mesna solution was injected into the submucosal layer. Mechanical submucosal dissection was then performed by bluntly cleaving the chemically treated submucosal layer with the tip of a cap-fitted gastroscope. The use of cautery was restricted to prophylactic hemostasis, dissection of the coagulated vessels and persistent submucosal tissues, and the final snare resection. Post-therapeutic ulceration repair and adverse events were followed up during a 1-week hospitalization and by repeat endoscopies at 1 day, 1 week, and 1 month after the procedure.
  
  
  RESULTS
  Sixteen gastric cancers and four adenomas were treated in this study. The sampled tissue measured 38.25 +/- 14.53 mm, with an en bloc resection rate of 100 %. Mean operation time was 21.17 +/- 11.6 minutes. The time spent using cautery was limited to 26.1 % of the total submucosal dissection time. Ulcerations healed normally without complications.
  
  
  CONCLUSIONS
  This preliminary study demonstrates that submucosal injection of mesna facilitates and expedites mechanical submucosal dissection. The major limitations in this study include the single-arm study design and a small patient population.
authors.affiliation: Department of Endoscopy, The Jikei University School of Medicine, Tokyo, Japan. kaz_sum@jikei.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Sumiyama
authors.forename: H
authors.initials: H
authors.lastname: Tajiri
authors.forename: C J
authors.initials: CJ
authors.lastname: Gostout
authors.forename: M
authors.initials: M
authors.lastname: Kawamura
authors.forename: H
authors.initials: H
authors.lastname: Imazu
authors.forename: T R
authors.initials: TR
authors.lastname: Ohya
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: K
authors.initials: K
authors.lastname: Goda
authors.forename: S
authors.initials: S
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Kato
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery; D000236:Adenoma / Q000601:surgery; D018279:Carcinoma, Signet Ring Cell / Q000601:surgery; D004210:Dissection / Q000379:methods*; D005100:Expectorants / Q000008:administration & dosage*; D005753:Gastric Mucosa / Q000601:surgery*; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D015080:Mesna / Q000008:administration & dosage*; D020011:Protective Agents / Q000008:administration & dosage*; D013274:Stomach Neoplasms / Q000601:surgery*
chemical_list: D005100:Expectorants; D020011:Protective Agents; D015080:Mesna