title: Transanal Endoscopic Operation for Rectal Tumor: Short-term Outcomes and Learning Curve Analysis.
abstract: OBJECTIVE
  We aim to report outcomes and learning curve of transanal endoscopic operation (TEO) for rectal tumors, using standard laparoscopic instruments under a magnifying laparoscopic monitor view.
  
  
  METHODS
  From January 2012 to July 2014, local excision was performed using a TEO system in 46 consecutive patients with rectal tumors. Patient and tumor characteristics and perioperative outcomes were prospectively assessed.
  
  
  RESULTS
  The median patient age was 56 years for 15 women and 31 men. The mean tumor size was 1.8 cm, and the mean distance from the anal verge was 7.8 cm. The mean operative time was 85 minutes, and the mean postoperative hospital stay was 4.5 days. The postoperative pathologic diagnosis was adenocarcinoma for 17 patients (37%), adenoma for 4 patients (9%), carcinoid tumor for 23 patients (50%), and leiomyoma and lipoma for the 2 remaining patients (2%). A positive resection margin was documented for 4 patients (9%). No mortality was associated with the procedure although postoperative bleeding, leakage, perianal fistula, fecal incontinence, and voiding difficulty developed in 8 patients. According to the cumulative sum (CUSUM) analysis, the operation time and hospital stay significantly decreased after 17 case experiences.
  
  
  CONCLUSIONS
  TEO is a feasible and safe treatment option for local excision of rectal tumors. TEO has the advantage of being a precise surgical procedure with a stable and magnifying endoscopic view. However, TEO requires a learning period and a careful selection of patients through proper indications and preoperative diagnostics.
authors.affiliation: Department of Surgery, Division of Colon and Rectal Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Hur
authors.forename: Sung Uk
authors.initials: SU
authors.lastname: Bae
authors.forename: Yoon Dae
authors.initials: YD
authors.lastname: Han
authors.forename: Jeonghyun
authors.initials: J
authors.lastname: Kang
authors.forename: Byung Soh
authors.initials: BS
authors.lastname: Min
authors.forename: Seung Hyuk
authors.initials: SH
authors.lastname: Baik
authors.forename: Kang Young
authors.initials: KY
authors.lastname: Lee
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D059032:Learning Curve; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D061646:Operative Time; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology; D011351:Proctoscopy / Q000379:methods*; D012004:Rectal Neoplasms / Q000601:surgery*; D016879:Salvage Therapy / Q000379:methods; D016896:Treatment Outcome