title: Endoscopic submucosal dissection: a safe technique for colorectal tumors.
abstract: OBJECTIVE
  Endoscopic submucosal dissection (ESD) aims to resect large neoplastic lesions en bloc, allowing for more precise histopathological analysis. The present retrospective study aimed to analyze the technical and clinical outcomes after ESD of colorectal tumors.
  
  
  METHODS
  ESD was performed for the treatment of 71 colorectal neoplasms in 70 patients (38 men, 32 women; mean age 63.4 years). Lesion size, procedure time, complications, and immediate and follow-up outcomes were evaluated. The results for these 71 lesions were compared with those for a group of 32 lesions treated by conventional piecemeal endoscopic mucosal resection (EMR) performed during the same period.
  
  
  RESULTS
  For the ESD-treated group of lesions, the average lesion size was 32.7 mm (range 13-80 mm), and the mean operating time was 61.1 minutes (range 7-164 minutes). One perforation occurred in the ESD group (1.4%) and this was treated conservatively with clipping. The majority of these lesions (n = 50) were laterally spreading tumors. Histological examination showed low-grade adenoma in 12 cases; high-grade intraepithelial neoplasia in 47 cases; and submucosally invasive cancer in 11 cases, of which four were sm1, and seven were sm2 or sm3 (these seven patients underwent surgery). The en bloc resection rate was 98.6%. For the 64 tumors that were treated by radical endoscopic resection, no tumor recurrence was found after a mean follow-up period of 12.2 months (range 3-34 months) and a mean of 2.1 follow-up endoscopies (range 1-4). This contrasted with the 6.3% recurrence rate in the 32 piecemeal EMR cases (mean tumor size 28.7 mm, range 20-60 mm).
  
  
  CONCLUSIONS
  In our hands, ESD is a safe and effective resection technique for large colorectal neoplasms. As experience with the technique increases, it might gradually replace piecemeal EMR in the majority of cases.
authors.affiliation: Department of Gastroenterology, International Medical Center of Japan, Tokyo, Japan. ytamegai@imcj.hosp.go.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Tamegai
authors.forename: Y
authors.initials: Y
authors.lastname: Saito
authors.forename: N
authors.initials: N
authors.lastname: Masaki
authors.forename: C
authors.initials: C
authors.lastname: Hinohara
authors.forename: T
authors.initials: T
authors.lastname: Oshima
authors.forename: E
authors.initials: E
authors.lastname: Kogure
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: N
authors.initials: N
authors.lastname: Uemura
authors.forename: K
authors.initials: K
authors.lastname: Saito
mesh_terms: D000236:Adenoma / Q000473:pathology; D000368:Aged; D002278:Carcinoma in Situ / Q000473:pathology; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D004210:Dissection / Q000295:instrumentation / Q000379:methods; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008067:Lipoma / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016896:Treatment Outcome