title: Cumulative summation analysis of learning curve for robot-assisted gastrectomy in gastric cancer.
abstract: BACKGROUND
  The purpose of this study was to determine the learning curve for robot-assisted gastrectomy using the Cumulative Summation (CUSUM) technique.
  
  
  METHODS
  Two series of consecutive robotic gastrectomy were retrospective analyzed. Patient demographics, surgical performance, and short-term outcomes were examined and data of operation time were abstracted for the learning curve analysis.
  
  
  RESULTS
  Similar processes occurred in the two surgeons. Each of their learning curves of robotic gastrectomy was best modeled as a third-order polynomial, with equation CUSUMOT in minutes equal to 0.0495 case number (3) - 4.217 case number(2) + 91.206 case number 100.11(R(2) =  .8731) for surgeon A and 0.0314 case number (3) - 2.4106 case number(2) + 33.682 case number + 315.28(R(2) = 0.8816) for surgeon B. They both included three unique phases: an initial phase, a well-developed phase, and a mastery phase after the accumulation of additional experience.
  
  
  CONCLUSIONS
  The CUSUM method is a useful tool for objective evaluation of practical skills for surgeons during the learning phase of robotic surgery training. The robotic gastrectomy is found to have a short learning curve for experienced laparoscopic surgeons and the popularity of this new technology won't reduce because of its difficulty to learn.
authors.affiliation: Department of General Surgery and Center of Minimal Invasive Gastrointestinal Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Feng
authors.initials: F
authors.lastname: Qian
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
authors.forename: Yingxue
authors.initials: Y
authors.lastname: Hao
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Peiwu
authors.initials: P
authors.lastname: Yu
mesh_terms: D005260:Female; D005743:Gastrectomy; D006801:Humans; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D012189:Retrospective Studies; D065287:Robotic Surgical Procedures; D013274:Stomach Neoplasms / Q000601:surgery*
keywords: CUSUM; gastric cancer; learning curve; robotic gastrectomy