title: Can Robotic Gastrectomy Surpass Laparoscopic Gastrectomy by Acquiring Long-Term Experience? A Propensity Score Analysis of a 7-Year Experience at a Single Institution.
abstract: OBJECTIVE
  It is hypothesized that robotic gastrectomy may surpass laparoscopic gastrectomy after the operators acquire long-term experience and skills in the manipulation of robotic arms. This study aimed to evaluate the long-term learning curve of robotic distal gastrectomy (RDG) for gastric cancer compared with laparoscopic distal gastrectomy (LDG).
  
  
  METHODS
  From October 2008 to December 2015, patients who underwent LDG (n=809) were matched to patients who underwent RDG (n=232) at a 1:1 ratio, by using a propensity score matching method after stratification for the operative year. The surgical outcomes, such as trends of operative time, blood loss, and complication rate, were compared between the two groups.
  
  
  RESULTS
  The RDG group showed a longer operative time (171.3 minutes vs. 147.6 minutes, P<0.001) but less estimated blood loss (77.6 ml vs. 116.6 ml, P<0.001). The complication rate and postoperative recovery did not differ between the two groups. The RDG group showed a longer operative time and similar estimated blood loss compared with the LDG group after 5 years of experience (operative time: 159.2 minutes vs. 136.0 minutes in 2015, P=0.003; estimated blood loss: 72.9 ml vs. 78.1 ml in 2015, P=0.793).
  
  
  CONCLUSIONS
  In terms of short-term surgical outcomes, RDG may not surpass LDG after a long-term experience with the technique.
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Hong
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Sang-Yong
authors.initials: SY
authors.lastname: Son
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Ho-Jung
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Long-Hai
authors.initials: LH
authors.lastname: Cui
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: Hur
authors.affiliation: Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Han
keywords: Gastrectomy; Laparoscopy; Learning curve; Robotics; Stomach neoplasms