title: Chronic pain after inguinal hernia repair with the ONSTEP versus the Lichtenstein technique, results of a double-blinded multicenter randomized clinical trial.
abstract: OBJECTIVE
  The open new simplified totally extraperitoneal (ONSTEP) technique for the repair of inguinal hernia was presented some years ago with promising initial results regarding chronic pain. We conducted a randomized clinical trial investigating the ONSTEP technique versus the Lichtenstein technique with focus on postoperative pain. The aim of this paper was to report the results regarding chronic pain from follow-up at 6 and 12 months for the participants in the ONSTEP versus Lichtenstein trial.
  
  
  METHODS
  This study was conducted as a randomized double-blinded clinical trial in male participants with primary unilateral hernias, having surgical repair of their hernia at one of five participating general surgical departments. At surgery, participants were allocated (1:1) to the ONSTEP or the Lichtenstein technique for inguinal hernia repair. Participants were followed up with questionnaires at 6 and 12 months. The primary outcome was the proportion of patients with substantial pain-related impairment of daily functions at 6- and 12-month follow-ups.
  
  
  RESULTS
  From April 2013 to May 2014, 290 male patients were included in the study. Regarding follow-up for pain, a total of 259 patients (89%) completed the 6-month follow-up and a total of 236 patients (81%) completed the 12-month follow-up. Regarding pain at the 6- and 12-month follow-ups, no difference was found between groups. Two patients operated with Lichtenstein technique developed severe disabling chronic pain postoperatively, which was not seen in the ONSTEP group.
  
  
  CONCLUSIONS
  The ONSTEP technique was not superior to the Lichtenstein technique regarding chronic pain following repair of primary inguinal hernias in males.
  
  
  BACKGROUND
  https://clinicaltrials.gov NCT01753219.
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark. kristofferandresen@gmail.com.|Department of Surgery, Herlev Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark. kristofferandresen@gmail.com.
authors.forename: Kristoffer
authors.identifier: http://orcid.org/0000-0002-9820-3580
authors.initials: K
authors.lastname: Andresen
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Burcharth
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Siv
authors.initials: S
authors.lastname: Fonnes
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Line
authors.initials: L
authors.lastname: Hupfeld
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Josephine Philip
authors.initials: JP
authors.lastname: Rothman
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Deigaard
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Dorte
authors.initials: D
authors.lastname: Winther
authors.affiliation: Department of Surgery, Horsens Hospital, Horsens, Denmark.
authors.forename: Maj-Britt
authors.initials: MB
authors.lastname: Errebo
authors.affiliation: Department of Surgery, Horsens Hospital, Horsens, Denmark.
authors.forename: Rikke
authors.initials: R
authors.lastname: Therkildsen
authors.affiliation: Department of Surgery, Bispebjerg Hospital, Bispebjerg, Denmark.
authors.forename: Dina
authors.initials: D
authors.lastname: Hauge
authors.affiliation: Dagkirurgisk Center Hobro, University Hospital Aalborg, Aalborg, Denmark.
authors.forename: Fritz Søbæk
authors.initials: FS
authors.lastname: Sørensen
authors.affiliation: Department of Surgery, Sygehus Lillebælt, Kolding Hospital, Kolding, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Bjerg
authors.affiliation: Center for Perioperative Optimization, Department of Surgery, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006552:Hernia, Inguinal / Q000601:surgery*; D059685:Herniorrhaphy / Q000009:adverse effects* / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D013526:Surgical Mesh; D016896:Treatment Outcome
keywords: Chronic pain; Inguinal hernia; Lichtenstein; ONSTEP; Randomized clinical trial