title: A systematic review of robotic-assisted liver resection and meta-analysis of robotic versus laparoscopic hepatectomy for hepatic neoplasms.
abstract: BACKGROUND
  Robotic-assisted liver resection (RALR) was introduced as procedures of overcoming the limitations of traditional laparoscopic liver resection (LLR). The aim of this review was to evaluate the surgical results of RALR from all published studies and the results of comparative studies of RALR versus LLR for hepatic neoplasm.
  
  
  METHODS
  Eligible studies involved RALR that published between January 2001 and December 2014 were reviewed systematically. Comparisons between RALS and LLR were pooled and analyzed by meta-analytical techniques using random- or fixed-effects models, as appropriate.
  
  
  RESULTS
  In total, 29 studies, involving 537 patients undergoing RALR, were identified. The most common RALR procedure was a wedge resection and segmentectomy (28.67%), followed by right hepatectomy (17.88%), left lateral sectionectomy (13.22%), and bisegmentectomy (9.12%). The conversion and complication rates were 5.59 and 11.36%, respectively. The most common reasons for conversion were bleeding (46.67%) and unclear tumor margin (33.33%). Intracavitary fluid collections and bile leaks (40.98%) were the most frequently occurring morbidities. Nine studies, involving 774 patients, were included in meta-analysis. RALR had a longer operative time compared with LLR [mean difference (MD) 48.49; 95% confidence interval (CI) 22.49-74.49 min; p = 0.0003]. There were no significant differences between the two groups in blood loss [MD 31.53; 95% CI -14.74 to 77.79 mL; p = 0.18], hospital stay [MD 0.13; 95% CI -0.54 to 0.80 days; p = 0.18], postoperative overall morbidity [odds ratio (OR) 0.76; 95% CI 0.49-1.19; p = 0.23], and surgical margin status (OR 0.61; 95% CI 0.33-1.12; p = 0.11); cost was greater than robotic surgery (p = 0.001).
  
  
  CONCLUSIONS
  RALR and LLR display similar safety, feasibility, and effectiveness for hepatectomies, but further studies are needed before any final conclusion can be drawn, especially in terms of oncologic and cost-effectiveness outcomes.
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China. qiujianguo456@163.com.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Qiu
authors.affiliation: Department of Hepatobiliary Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China.
authors.forename: Shuting
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China. duchengyoucyfyy@163.com.
authors.forename: Du
authors.initials: D
authors.lastname: Chengyou
mesh_terms: D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D007902:Length of Stay; D008113:Liver Neoplasms / Q000601:surgery*; D016017:Odds Ratio; D061646:Operative Time; D011184:Postoperative Period; D065287:Robotic Surgical Procedures; D016896:Treatment Outcome
keywords: Hepatic tumor; Laparoscopy; Meta-analysis; Robotic; Systematic review