title: Ultrasonic versus electrosurgical device for laparoscopic cholecystectomy: A systematic review with meta-analysis and trial sequential analysis.
abstract: BACKGROUND
  Ultrasonic and electrosurgical energy dissectors are main dissecting devices widely used for the laparoscopic cholecystectomy. Trial sequential analyses can establish whether firm evidence favoring a specific device has been reached from accumulated literature. To explore this, we performed a meta-analysis and trial sequential analyses.
  
  
  METHODS
  PubMed, Embase, and the Cochrane Library were searched from inception to October 2016. The primary outcome was operative time. The secondary outcomes included adverse events during operation, postoperative complications, intra-abdominal collection, hospital stay, hospital costs, and sick leave or time to full recovery. Relative risks (RRs) were calculated for dichotomous outcomes and mean differences (MDs) for continuous outcomes. Finally, we calculated numbers needed to treat to examine benefits of the ultrasonic device.
  
  
  RESULTS
  We identified 19 studies. Compared with the electrosurgical device, the ultrasonic device led to shorter operative time (MD, -14.86; 95% confidence interval (CI), -21.45 to -8.27; P < 0.00001), less blood loss (MD, -47.24; 95% CI, -79.57 to -14.90; P = 0.004), fewer gallbladder perforations (RR, 0.45; 95% CI, 0.35 to 0.57; P < 0.00001), shorter hospital stay (MD, -0.37; 95% CI, -0.61 to -0.14; P = 0.002), and fewer abdominal pains (MD, -0.95; 95% CI, -1.40 to -0.50; P < 0.0001). The trial sequential analysis demonstrated that the cumulative z-curve crossed the trial sequential monitoring and reached the required information size of the operative time. The numbers needed to treat to avoid one gallbladder perforation and postoperative nausea, respectively, were 7 and 15.
  
  
  CONCLUSIONS
  Compared with the electrosurgery device, the ultrasonic device could be superior with more clinical effectiveness. The trial sequential analysis demonstrated that further studies about the operative time were not needed.
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, People's Republic of China.
authors.forename: Hong-Peng
authors.initials: HP
authors.lastname: Jiang
authors.affiliation: Department of Urinary Surgery, The First Clinical Hospital, Harbin Medical University, Harbin 150001, People's Republic of China.
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Liu
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, People's Republic of China.
authors.forename: Yan-Sen
authors.initials: YS
authors.lastname: Li
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, People's Republic of China. Electronic address: shenlong1977@163.com.
authors.forename: Zhan-Long
authors.initials: ZL
authors.lastname: Shen
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, People's Republic of China. Electronic address: yeyingjiang@pkuph.edu.cn.
authors.forename: Ying-Jiang
authors.initials: YJ
authors.lastname: Ye
mesh_terms: D017081:Cholecystectomy, Laparoscopic / Q000295:instrumentation* / Q000379:methods; D004210:Dissection / Q000295:instrumentation*; D004598:Electrosurgery / Q000295:instrumentation*; D006801:Humans; D007902:Length of Stay; D061646:Operative Time; D011183:Postoperative Complications / Q000209:etiology*; D059708:Ultrasonic Surgical Procedures / Q000295:instrumentation*
keywords: Dissection; Electrosurgical; Laparoscopic cholecystectomy; Meta-analysis; Trial sequential analysis; Ultrasonic