title: Comparison of trans-anal endoscopic operation and trans-anal excision of rectal tumors.
abstract: BACKGROUND
  Trans-anal endoscopic operation (TEO) has developed to facilitate proper tumor location and ensure excision safely.
  
  
  METHODS
  We reviewed 92 patients enrolled in our database between 2006 and 2014 who were diagnosed with early rectal tumors and who underwent conventional trans-anal excision (TAE) or TEO. Clinical data were collected prospectively to compare safety and feasibility between two techniques.
  
  
  RESULTS
  Ninety-two patients underwent trans-anal local excision for lower rectal tumors. TEO and TAE were performed in 48 and 44 patients, respectively. Age, sex, and comorbidities were similar. There was no significant difference in tumor diameter (1.6 ± 1.68 cm vs. 1.17 ± 1.17, respectively). Tumor height, however, was higher in the TEO (7.46 ± 3 cm) than the TAE group (3.84 ± 1.88 cm, p < 0.001). Four complications, perianal abscess, and two perforations, occurred in the TEO group, whereas no major complications occurred in the TAE. Seven patients (14.6%) underwent TEO underwent a salvage operation compared to only a single patient in TAE group (2.3%, p = 0.039). Eight patients (17.4%) diagnosed with adenocarcinoma developed recurrence, four in each group. Disease-free survival was similar between groups (TEO - 41.8 months, 95% RI 39.4-44.1; TAE 79.7 months, 95% RI 72.2-87.3). However, more TAE patients (n = 7, 15.9%) than TEO patients (n = 2, 4.2%) underwent chemotherapy.
  
  
  CONCLUSIONS
  TEO treatment of local rectal tumors is safe and feasible and can achieve an adequate resection margin. Local recurrence was similar in both groups. However, the numbers of salvage operations and minor complications were higher in the TEO group.
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Mahdi Hussain
authors.initials: MH
authors.lastname: Al Bandar
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yoon Dae
authors.initials: YD
authors.lastname: Han
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Syed Asim
authors.initials: SA
authors.lastname: Razvi
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Cho
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Hur
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Byung Soh
authors.initials: BS
authors.lastname: Min
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kang Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Division of Colorectal Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
keywords: Rectal tumors; Trans-anal endoscopic operation; Trans-anal excision operation