title: Radially expanding trocar: a less painful alternative for laparoscopic surgery.
abstract: OBJECTIVE
  One advantage of minimal-access surgery is that it produces less pain. A radially expanding trocar has been claimed to reduce pain further. We aimed to evaluate this claim.
  
  
  METHODS
  This was a randomized controlled single-blind clinical trial. Fifty-four patients who underwent laparoscopic cholecystectomy at the Department of Surgery, United Christian Hospital, Hong Kong, between July 1997 and September 1998 were randomized into either the study group or the control group. The radially expanding 10-mm trocar was used for the epigastric port in the study group. The conventional 10-mm metal trocar was used similarly in the control group. The operation was otherwise performed with a standardized technique. Another conventional 10-mm metal trocar was used for the subumbilical port for all patients. Pain was measured using a visual analog scale. Pain scores for the epigastric port and subumbilical port were documented for 3 days after the surgery.
  
  
  RESULTS
  There was no difference in age, sex, diagnoses, operating time, or conversion rate. There was consistently no difference in the pain experienced in the subumbilical wound, whereas pain at the epigastric wound was consistently less with the radially expanding trocar (p < 0.05).
  
  
  CONCLUSIONS
  The radially expanding trocar produces less early postoperative pain than the conventional metal trocar.
authors.affiliation: Department of Surgery, United Christian Hospital, Kowloon, Hong Kong, China.
authors.forename: T Y
authors.initials: TY
authors.lastname: Lam
authors.forename: S W
authors.initials: SW
authors.lastname: Lee
authors.forename: H S
authors.initials: HS
authors.lastname: So
authors.forename: S P
authors.initials: SP
authors.lastname: Kwok
mesh_terms: D004867:Equipment Design; D005260:Female; D006801:Humans; D020706:Laparoscopes / Q000009:adverse effects*; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control*; D011446:Prospective Studies; D016037:Single-Blind Method; D013525:Surgical Instruments / Q000009:adverse effects*