title: A Systematic Review of Outcomes After Transanal Mesorectal Resection for Rectal Cancer.
abstract: BACKGROUND
  Transanal mesorectal resection has been developed to facilitate minimally invasive proctectomy for rectal cancer.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the evidence regarding technical parameters, oncological outcomes, morbidity, and mortality after transanal mesorectal resection.
  
  
  METHODS
  The Cochrane Library, PubMed, and MEDLINE databases were reviewed.
  
  
  METHODS
  Systematic review of the literature from January 2005 to September 2015 was used for study selection.
  
  
  METHODS
  Intervention included transanal mesorectal resection for rectal cancer.
  
  
  METHODS
  Technical parameters, histological outcomes, morbidity, and mortality were the outcomes measured.
  
  
  RESULTS
  Fifteen predominately retrospective studies involving 449 patients were included (mean age, 64.3 years; 64.1% men). Different platforms were used. The operative mortality rate was 0.4% and the cumulative morbidity rate 35.5%. Circumferential resection margins were clear in 98%, and the resected mesorectum was grade III in 87% of patients. Median follow-up was 14.7 months. There were 4 local recurrences (1.5%) and 12 patients (5.6%) with metastatic disease. No study followed patients long enough to report on 5-year overall and disease-free survival rates. Functional outcome was only reported in 3 studies.
  
  
  CONCLUSIONS
  A low number of procedures were performed by expert early adopters. There are no comparative or randomized data included in this study and inconsistent reporting of outcome variables.
  
  
  CONCLUSIONS
  Transanal mesorectal resection for rectal cancer may enhance negative circumferential margin rates with a reasonable safety profile. Contemporary randomized, controlled studies are required before there can be universal recommendation.
authors.affiliation: Department of Colorectal Surgery, Castlehill Hospital, Cotttingham, East Yorkshire, United Kingdom.
authors.forename: Lakshmanan
authors.initials: L
authors.lastname: Arunachalam
authors.forename: Helen
authors.initials: H
authors.lastname: O'Grady
authors.forename: Iain A
authors.initials: IA
authors.lastname: Hunter
authors.forename: Shane
authors.initials: S
authors.lastname: Killeen
mesh_terms: D018572:Disease-Free Survival; D006801:Humans; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000601:surgery*; D000067368:Transanal Endoscopic Surgery; D016896:Treatment Outcome