title: Treatment efficacy of sacral nerve stimulation in slow transit constipation: a two-phase, double-blind randomized controlled crossover study.
abstract: OBJECTIVE
  Sacral nerve stimulation (SNS) is a potential treatment for constipation refractory to standard therapies. However, there have been no randomized controlled studies examining its efficacy. In patients with slow transit constipation, we evaluated the efficacy of suprasensory and subsensory SNS compared with sham, in a prospective, 18-week randomized, double-blind, placebo-controlled, two-phase crossover study. The primary outcome measure was the proportion of patients who, on more than 2 days/week for at least 2 of 3 weeks, reported a bowel movement associated with a feeling of complete evacuation.
  
  
  METHODS
  After 3 weeks of temporary peripheral nerve evaluation (PNE), all patients had permanent implantation and were randomized to subsensory/sham (3 weeks each) and then re-randomized to suprasensory/sham (3 weeks each) with a 2-week washout period between each arm. Daily stool dairies were kept, and quality of life (QoL; SF36) was measured at the end of each arm.
  
  
  RESULTS
  Between November 2006 and March 2012, 234 constipated patients were assessed, of whom 59 were willing and deemed eligible to participate (4 male; median age 42 years). Of the 59 patients, 16 (28%) responded to PNE. Fifty-five patients went on to permanent SNS implantation. The proportion of patients satisfying the primary outcome measure did not differ between suprasensory (30%) and sham (21%) stimulations, nor between subsensory (25%) and sham (25%) stimulations. There were no significant changes in QoL scores.
  
  
  CONCLUSIONS
  In patients with refractory slow transit constipation, SNS did not improve the frequency of complete bowel movements over the 3-week active period.
authors.affiliation: 1] Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia [2] Department of Gastroenterology and Surgery, Flinders Medical Centre, Flinders University, South Australia, Australia.
authors.forename: Phil G
authors.initials: PG
authors.lastname: Dinning
authors.affiliation: Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Hunt
authors.affiliation: 1] Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia [2] Department of Anorectal Physiology, St George Hospital, Kogarah, New South Wales, Australia.
authors.forename: Vicki
authors.initials: V
authors.lastname: Patton
authors.affiliation: Department of Gastroenterology, St. George Hospital, Kogarah, New South Wales, Australia.
authors.forename: Teng
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia.
authors.forename: Michal
authors.initials: M
authors.lastname: Szczesniak
authors.affiliation: Department of Biostatistics and Research Methodology, NHMRC Clinical Trials Centre, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Val
authors.initials: V
authors.lastname: Gebski
authors.affiliation: Department of Psychology, Macquarie University, Ryde, New South Wales, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Jones
authors.affiliation: Department of Surgery, The Concord Repatriate Hospital, Concord, New South Wales, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Stewart
authors.affiliation: 1] Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia [2] Department of Anorectal Physiology, St George Hospital, Kogarah, New South Wales, Australia.
authors.forename: David Z
authors.initials: DZ
authors.lastname: Lubowski
authors.affiliation: 1] Faculty of Medicine, St. George Hospital Clinical School, University of New South Wales, Kogarah, New South Wales, Australia [2] Department of Gastroenterology, St. George Hospital, Kogarah, New South Wales, Australia.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Cook
mesh_terms: D000328:Adult; D000368:Aged; D003248:Constipation / Q000503:physiopathology* / Q000628:therapy*; D018592:Cross-Over Studies; D003672:Defecation; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005772:Gastrointestinal Transit; D006801:Humans; D058542:Implantable Neurostimulators; D008160:Lumbosacral Plexus; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D012684:Sensory Thresholds; D055815:Young Adult