title: Modified endoscopic submucosal dissection with enucleation for treatment of gastric subepithelial tumors originating from the muscularis propria layer.
abstract: BACKGROUND
  Gastric subepithelial tumors are usually asymptomatic and observed incidentally during endoscopic examination. Although most of these tumors are considered benign, some have a potential for malignant transformation, particularly those originating from the muscularis propria layer. For this type of tumor, surgical resection is the standard treatment of choice. With recent advent of endoscopic resection techniques and devices, endoscopic submucosal dissection (ESD) has been considered as an alternative way of treatment. The aim of this study is to demonstrate the feasibility of a modified ESD technique with enucleation for removal of gastric subepithelial tumors originating from the muscularis propria layer, and to evaluate its efficacy and safety.
  
  
  METHODS
  From November 2009 to May 2011, a total of 16 patients received a modified ESD with enucleation for their subepithelial tumors. All tumors were smaller than 5 cm and originated from the muscularis propria layer of the stomach, as shown by endoscopic ultrasonography (EUS). The procedure was conducted with an insulated-tip knife 2. Patient's demographics, tumor size and pathological diagnosis, procedure time, procedure-related complication, and treatment outcome were reviewed.
  
  
  RESULTS
  Fifteen of the sixteen tumors were successful complete resection. The mean tumor size measured by EUS was 26.1 mm (range: 20-42 mm). The mean procedure time was 52  minutes (range: 30-120  minutes). Endoscopic features of the 4 tumors were pedunculated and 12 were sessile. Their immunohistochemical diagnosis was c-kit (+) stromal tumor in 14 patients and leiomyoma in 2 patients. There was no procedure-related perforation or overt bleeding. During a mean follow up duration of 14.8  months (range: 6-22  months), there was no tumor recurrence or metastasis.
  
  
  CONCLUSIONS
  Using a modified ESD with enucleation for treatment of gastric subepithelial tumors originating from the muscularis propria layer and larger than 2 cm, complete resection can be successfully performed without serious complication. It is a safe and effective alternative to surgical therapy for these tumors of 2 to 5 cm in size.
authors.affiliation: Department of Internal Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yin-Yi
authors.initials: YY
authors.lastname: Chu
authors.forename: Jau-Min
authors.initials: JM
authors.lastname: Lien
authors.forename: Ming-Hung
authors.initials: MH
authors.lastname: Tsai
authors.forename: Cheng-Tang
authors.initials: CT
authors.lastname: Chiu
authors.forename: Tse-Ching
authors.initials: TC
authors.lastname: Chen
authors.forename: Kuo-Ching
authors.initials: KC
authors.lastname: Yang
authors.forename: Soh-Ching
authors.initials: SC
authors.lastname: Ng
mesh_terms: D000328:Adult; D000368:Aged; D004210:Dissection / Q000379:methods*; D019160:Endosonography / Q000379:methods; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D007889:Leiomyoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome