title: Two-dimensional versus three-dimensional laparoscopy in surgical efficacy: a systematic review and meta-analysis.
abstract: BACKGROUND
  Laparoscopy is a revolutionary technique in modern surgery. However, the comparative efficacy between two-dimensional laparoscopy and three-dimensional laparoscopy remains in uncertainty. Therefore we performed this systematic review and meta-analysis in order to seek for answers.
  
  
  METHODS
  Databases of PubMed, Web of Science, EMBASE and Cochrane Library were carefully screened. Clinical trials comparing two-dimensional versus three-dimensional laparoscopy were included for pooled analysis. Observational and randomized trials were methodologically appraised by Newcastle-Ottawa Scale and Revised Jadad's Scale respectively. Subgroup analyses were additionally conducted to clarify the potential confounding elements. Outcome stability was examined by sensitivity analysis, and publication bias was analyzed by Begg's test and Egger's test.
  
  
  RESULTS
  21 trials were screened out from the preliminary 3126 records. All included studies were high-quality in methodology, except for Bilgen 2013 and Ruan 2015. Three-dimensional laparoscopy was superior to two-dimensional laparoscopy in terms of surgical time (P < 0.00001), blood loss (P = 0.01), perioperative complications (P = 0.04) and hospital stay (P = 0.03). Additionally, both techniques demonstrated comparable results of secondary endpoints, including drainage volume (P = 0.74), drainage time (P = 0.26), numbers of retrieved lymphnodes (P = 0.85), hospital expenses (P = 0.49), anastomosis time in prostatectomy (P=0.15) and 6-month continence rate (P = 0.61). The pooled outcomes of primary endopoints were verified to be stable by sensitivity analysis. Although Begg's test (P = 0.215) and Egger's test (P = 0.003) revealed that there was publication bias across included studies, Trim-and-Fill method confirmed that the results remained stable.
  
  
  CONCLUSIONS
  Three-dimensional laparoscopy is a preferably surgical option against two-dimensional laparoscopy due to its better surgical efficacy.
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Shuai
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Guobin
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Kaixiong
authors.initials: K
authors.lastname: Tao
mesh_terms: D000005:Abdomen / Q000601:surgery; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D002986:Clinical Trials as Topic; D004322:Drainage / Q000706:statistics & numerical data; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects / Q000191:economics / Q000379:methods* / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data; D061646:Operative Time; D011183:Postoperative Complications / Q000453:epidemiology*; D016896:Treatment Outcome
keywords: meta-analysis; surgical efficacy; systematic review; three-dimensional laparoscopy; two-dimensional laparoscopy