title: Learning curve in robotic rectal cancer surgery: current state of affairs.
abstract: BACKGROUND
  Robotic-assisted rectal cancer surgery offers multiple advantages for surgeons, and it seems to yield the same clinical outcomes as regards the short-time follow-up of patients compared to conventional laparoscopy. This surgical approach emerges as a technique aiming at overcoming the limitations posed by rectal cancer and other surgical fields of difficult access, in order to obtain better outcomes and a shorter learning curve.
  
  
  METHODS
  A systematic review of the literature of robot-assisted rectal surgery was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search was conducted in October 2015 in PubMed, MEDLINE and the Cochrane Central Register of Controlled Trials, for articles published in the last 10 years and pertaining the learning curve of robotic surgery for colorectal cancer. It consisted of the following key words: "rectal cancer/learning curve/robotic-assisted laparoscopic surgery".
  
  
  RESULTS
  A total of 34 references were identified, but only 9 full texts specifically addressed the analysis of the learning curve in robot-assisted rectal cancer surgery, 7 were case series and 2 were non-randomised case-comparison series. Eight papers used the cumulative sum (CUSUM) method, and only one author divided the series into two groups to compare both. The mean number of cases for phase I of the learning curve was calculated to be 29.7 patients; phase II corresponds to a mean number 37.4 patients. The mean number of cases required for the surgeon to be classed as an expert in robotic surgery was calculated to be 39 patients.
  
  
  CONCLUSIONS
  Robotic advantages could have an impact on learning curve for rectal cancer and lower the number of cases that are necessary for rectal resections.
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain. ros_j_r@hotmail.com.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Jiménez-Rodríguez
authors.affiliation: Department of General and Digestive Surgery, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Rubio-Dorado-Manzanares
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Díaz-Pavón
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Reyes-Díaz
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: Jorge Manuel
authors.initials: JM
authors.lastname: Vazquez-Monchul
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Garcia-Cabrera
authors.affiliation: Department of General and Digestive Surgery, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Padillo
authors.affiliation: Department of General and Digestive Surgery, Colorectal Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: De la Portilla
mesh_terms: D006801:Humans; D007430:Intraoperative Care; D010535:Laparoscopy; D059032:Learning Curve; D011183:Postoperative Complications / Q000209:etiology; D012004:Rectal Neoplasms / Q000601:surgery*; D012371:Robotics
keywords: Learning curve; Minimally invasive surgery; Rectal cancer; Rectal surgery; Robotic surgery