title: Retention test in sacral nerve stimulation for fecal incontinence.
abstract: BACKGROUND
  Sacral nerve stimulation has become an established treatment for patients with fecal incontinence. However, the mechanism of its action remains obscure. We aim to assess whether sacral nerve stimulation improves patients' ability to retain rectal content.
  
  
  METHODS
  Patients who had been treated successfully with sacral nerve stimulation underwent four retention tests during which the stimulator was turned either on or off. Both the patients and investigators were blinded to the status of the stimulator. The retention test results were assessed for interassessment agreement and for any differences between the on and off phases. Wexner scores, anorectal physiology tests, and patients' perceptions of stimulator settings were also recorded.
  
  
  RESULTS
  Nineteen patients (16 women; mean age, 57.5 years) took part in the study. Retention tests showed moderate interassessment agreement (weighted Cohen's kappa index, 0.45). There were no sharp differences in retained volume between the stimulator's on and off phases (median 50 (range, 0-300) mL vs. 50 (range, 0-300) mL; P = 0.85).
  
  
  CONCLUSIONS
  Sacral nerve stimulation does not alter patients' ability to retain rectal content. Further studies are needed to investigate the mechanism of sacral nerve stimulation.
authors: Surgical Research Unit, Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark. hbn@mail.tele.dk
authors: Hanne B
authors: HB
authors: Michelsen
authors: Yasuko
authors: Y
authors: Maeda
authors: Lilli
authors: L
authors: Lundby
authors: Klaus
authors: K
authors: Krogh
authors: Steen
authors: S
authors: Buntzen
authors: Søren
authors: S
authors: Laurberg
mesh_terms: D004599:Electric Stimulation Therapy / Q000379:methods*; D005242:Fecal Incontinence / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008160:Lumbosacral Plexus / Q000502:physiology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D012007:Rectum / Q000294:innervation*; D016896:Treatment Outcome