title: Tunneling endoscopic muscularis dissection for subepithelial tumors originating from the muscularis propria of the esophagus and gastric cardia.
abstract: OBJECTIVE
  Endoscopic resection of esophageal or cardial subepithelial tumors (SETs) originating from the muscularis propria (MP) is rarely done due to the high risk of perforation, fistula formation, and secondary infection. The aim of this study was to evaluate the preliminary clinical feasibility and safety of tunneling endoscopic muscularis dissection (tEMD) for resection of SETs located in the esophagus and gastric cardia
  
  
  METHODS
  Twelve patients with SETs originating from the MP of the esophagus (n = 7) or cardia (n = 5) were treated by tEMD. The procedure included creation of a submucosal tunnel to reach the tumor, dissection of the tumor from the surrounding submucosal tissue and the unaffected MP layer, full-thickness resection of the tumor and affected MP, and subsequent closure of the tunnel mucosal entry with endoscopic clips.
  
  
  RESULTS
  The en bloc resection rate was 100 % (seven lesions affected the deep MP so complete MP resection was performed; five lesions affected the superficial MP for a partial MP resection). The average tumor size was 18.5 ± 6.9 (range 10-30) mm. The mean operating time was 78.3 ± 25.5 (range 50-130) min. The histological diagnoses were two gastrointestinal stromal tumors with very low risk, nine leiomyomas, and one schwannoma. Air leakage and effusion included subcutaneous and mediastinal emphysema in eight patients (66.7 %), pneumothorax in four (33.3 %), pneumoperitoneum in three (25.0 %), and small pleural effusion in two (16.7 %). All air leakage and effusion cases were resolved with conservative management. No patient developed delayed hemorrhage and chronic fistula after tEMD. During the mean follow-up time of 7.1 ± 4.3 (range 2-15) months, no tumor recurrence was found in any patient.
  
  
  CONCLUSIONS
  tEMD appears to be a feasible minimally invasive and effective treatment for patients with SETs originating from the MP layer of the esophagus and cardia.
authors.affiliation: Department of Gastroenterology and Hepatology, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Nangang District, Harbin, 150086, People's Republic of China, liubingrong@medmail.com.cn.
authors.forename: Bing-Rong
authors.initials: BR
authors.lastname: Liu
authors.forename: Ji-Tao
authors.initials: JT
authors.lastname: Song
authors.forename: Ling-Jian
authors.initials: LJ
authors.lastname: Kong
authors.forename: Feng-Hua
authors.initials: FH
authors.lastname: Pei
authors.forename: Xin-Hong
authors.initials: XH
authors.lastname: Wang
authors.forename: Ya-Ju
authors.initials: YJ
authors.lastname: Du
mesh_terms: D000328:Adult; D000368:Aged; D057868:Anastomotic Leak / Q000209:etiology; D002299:Cardia / Q000601:surgery; D004210:Dissection / Q000009:adverse effects / Q000379:methods; D004646:Emphysema / Q000209:etiology; D004938:Esophageal Neoplasms / Q000601:surgery*; D004945:Esophagoscopy / Q000009:adverse effects / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000601:surgery; D046152:Gastrointestinal Stromal Tumors / Q000473:pathology / Q000601:surgery*; D005773:Gastroscopy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007889:Leiomyoma / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D061646:Operative Time; D010996:Pleural Effusion / Q000209:etiology; D011027:Pneumoperitoneum / Q000209:etiology; D011030:Pneumothorax / Q000209:etiology; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome