title: Medium-term outcome of sacral nerve modulation for constipation.
abstract: BACKGROUND
  Sacral nerve modulation has been reported as a minimally invasive and effective treatment for constipation refractory to conservative treatment.
  
  
  OBJECTIVE
  This study aimed to evaluate the efficacy and sustainability of sacral nerve modulation for constipation in the medium term (up to 6 years) and to investigate potential predictors of treatment success.
  
  
  METHODS
  We performed a retrospective review of prospectively collected data.
  
  
  METHODS
  The study was performed at 2 tertiary-care centers in Europe with expertise in pelvic floor disorders and sacral nerve modulation.
  
  
  METHODS
  Patients were eligible if they had had symptoms of constipation persisting for at least 1 year, if conservative treatment (dietary modification, laxatives and biofeedback therapy) had failed, and if predefined excluded conditions were not present.
  
  
  METHODS
  The first phase of the treatment process was percutaneous nerve evaluation. If this was successful, patients underwent sacral nerve modulation therapy with an implanted device (tined-lead and implantable pulse generator).
  
  
  METHODS
  Follow-up was performed at 1, 3, 6, and 12 months, and yearly thereafter. Outcome was assessed with the Wexner constipation score.
  
  
  RESULTS
  A total of 117 patients (13 men, 104 women) with a mean age of 45.6 (SD, 13.0) years underwent percutaneous nerve evaluation. Of these, 68 patients (58%) had successful percutaneous nerve evaluation and underwent implantation of a device. The mean Wexner score was 17.0 (SD, 3.8) at baseline and 10.2 (SD 5.3) after percutaneous nerve evaluation (p < .001); the improvement was maintained throughout the follow-up period, although the number of patients continuing with sacral nerve modulation at the latest follow-up (median, 37 months; range, 4-92) was only 61 (52% of all patients who underwent percutaneous nerve evaluation). The sole predictive factor of outcome of percutaneous nerve evaluation was age: younger patients were more likely than older patients to have a successful percutaneous nerve evaluation phase.
  
  
  CONCLUSIONS
  The study was limited by a lack of consistent outcome measures.
  
  
  CONCLUSIONS
  : Despite improvement in Wexner scores, at the latest follow-up sacral nerve modulation was only being used by slightly more than 50% of the patients who started the first phase of treatment. Further studies are needed to reassess the efficacy and sustainability of sacral nerve modulation.
authors.affiliation: Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands. b.govaert@mumc.nl
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Govaert
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Maeda
authors.forename: Job
authors.initials: J
authors.lastname: Alberga
authors.forename: Steen
authors.initials: S
authors.lastname: Buntzen
authors.forename: Søren
authors.initials: S
authors.lastname: Laurberg
authors.forename: Cornelius G
authors.initials: CG
authors.lastname: Baeten
mesh_terms: D000328:Adult; D000367:Age Factors; D003248:Constipation / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000295:instrumentation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D058542:Implantable Neurostimulators; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012445:Sacrococcygeal Region / Q000294:innervation*; D016896:Treatment Outcome