title: A randomized controlled trial comparing post-operative pain in single-incision laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy.
abstract: BACKGROUND
  An increasing body of evidence is being published about single-incision laparoscopic cholecystectomy (SILC), but there are no well-powered trials with an adequate evaluation of post-operative pain. This randomized trial compares SILC against four-port laparoscopic cholecystectomy (LC) with post-operative pain as the primary endpoint.
  
  
  METHODS
  Hundred patients were randomized to either SILC (n = 50) or LC (n = 50). Exclusion criteria were (1) Acute cholecystitis; (2) ASA 3 or above; (3) Bleeding disorders; and (4) Previous open upper abdominal surgery. Patients and post-operative assessors were blinded to the procedure performed. The site and severity of pain were compared at 4 h, 24 h, 14 days and 6 months post-procedure using the visual analog scale; non-inferiority was assumed when the lower boundary of the 95% confidence interval of the difference was above -1 and superiority when p ≤ 0.05.
  
  
  RESULTS
  The study arms were demographically similar. At 24 h post-procedure, SILC was associated with less pain at extra-umbilical sites (rest: p = 0.004; movement: p = 0.008). Pain data were inconclusive at 24 h at the umbilical site on movement; SILC was otherwise non-inferior for pain at all other points. Operating duration was longer in SILC (79.46 vs 58.88 min, p = 0.003). 8% of patients in each arm suffered complications (p = 1.000). Re-intervention rates, analgesic use, return to function, and patient satisfaction did not differ significantly.
  
  
  CONCLUSIONS
  SILC has improved short-term pain outcomes compared to LC and is not inferior in both short-term and long-term pain outcomes. The operating time is longer, but remains feasible in routine surgical practice.
authors.affiliation: Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, National University Health System, 1E Kent Ridge Road, NUHS Tower Block, Level 8, Singapore, 119228, Singapore, cfscky@nus.edu.sg.
authors.forename: Stephen Kin Yong
authors.initials: SK
authors.lastname: Chang
authors.forename: Yi Liang
authors.initials: YL
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Shen
authors.forename: Shridhar Ganpathi
authors.initials: SG
authors.lastname: Iyer
authors.forename: Krishnakumar
authors.initials: K
authors.lastname: Madhavan
mesh_terms: D000328:Adult; D000368:Aged; D000700:Analgesics / Q000627:therapeutic use; D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology*; D017060:Patient Satisfaction; D012086:Reoperation; D018709:Statistics, Nonparametric; D013997:Time Factors; D014472:Umbilicus
chemical_list: D000700:Analgesics