Spinal Cord Stimulation for Pain Relief in Irritable Bowel Syndrome
Condition: Irritable Bowel Syndrome; Constipation; Diarrhea; Pain
MeSH terms: Irritable Bowel Syndrome; Syndrome; Constipation; Diarrhea
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      To elucidate Spinal Cord Stimulation (SCS) as treatment for IBS. An SCS system with a 4-polar
      electrode at the T5-8 level is implanted. In a randomized, cross-over study design, active
      stimulation is compared to a period without stimulation, with an ensuing tailing stimulation
      period, twice as long. Patients recorded average pain level, pain attacks, number of
      diarrheas and global quality of life. At the end of the study patients can choose to retain
      their SCS stimulation system or have it removed.

      The outcome of the present trial will show whether SCS is a useful treatment of IBS. The
      long-term follow-up will show the continuous amelioration of SCS over at least six months.
    

Detailed description: 
      The primary aim of the study is to investigate if the typical chronic abdominal pain in IBS
      can be ameliorated by SCS. Secondary aims are possible effects of SCS on diarrhea or
      constipation, quality of life and side effects, and further to evaluate the feasibility and
      tolerability of SCS as validated by the willingness of the patients to retain the SCS
      stimulation equipment.

      Eligible patients are selected by a gastroenterologist for the study inclusion criteria: age
      18-60, fulfilment of Rome II criteria, abdominal pain episodically reaching > 4 on a 0-10
      VAS, and stable symptoms for the past 2 years. A thorough clinical work-up is done to exclude
      organic disease, including routine blood and electrolyte status, hepatic enzyme function and
      lactose tolerance test as well as colonoscopy or colon x-ray. Patients with significant
      somatic or psychiatric co-morbidity will be excluded.

      Study design: A quadripolar SCS-lead (Quad-plus®, Medtronic Inc., Minnesota, USA) was
      implanted via a percutaneous puncture at the Th11/12 level of the dorsal epidural space in
      local anesthesia with the patient in the prone position. The electrode is advanced to the
      mid-thoracic level, aiming for a final position around T6-T8, until intraoperative
      stimulation yields paresthesias covering the abdomen . The electrode is then connected to an
      impulse generator (Itrel-3®, Medtronic Inc.) implanted subcutaneously in the upper left
      quadrant of the abdomen. Stimulation frequency will be set to 50 Hz for all patients but
      other parameters (electrode pole combinations, amplitudes and pulse width) are adjusted and
      set to produce adequate paresthesias of comfortable intensity.

      During the subsequent ongoing trial reprogramming was allowed, if necessary for optimal
      stimulation.

      SCS will be started 2 weeks after surgery. Thereafter patients are randomized to either of
      two study arms: one starting with SCS for a period of six weeks (A), and another with six
      weeks without SCS (delayed start) (B). When on active SCS, patients are prompted to stimulate
      8-12 h per day. Patients are instructed to increase the stimulation upon pain attack
      break-through.

      After six weeks, patients without stimulation were crossed-over to stimulation and vice
      versa. After another six weeks both study arms included continued stimulation for additional
      12 weeks up to 26 weeks. After a final 2-week period without stimulation the trial is
      terminated.

      During the whole study period patients will record, on a daily basis: 1) number of pain
      attacks, 2) number of diarrhea episodes, 3) average pain level for the day (0-10) and 4)
      average quality of life (0-10).

      Patients are scheduled for regular controls, at 2, 8, 14, 26 and 28 weeks after implantation.
      Patient compliance will be ensured, as the impulse generator stores information on the
      percentage of elapsed time that stimulation has been in use.

      At termination of the study participants were offered to keep the implanted SCS system or
      have it removed.

      All patients will be contacted for a structured telephone interview follow-up at a time-point
      varying between 18 to 78 months after the study termination. A questionnaire was used to
      assess present pain level, medication, use of the SCS system, side effects and global
      satisfaction. Patients will also be asked whether they would have participated if they had
      known the outcome in advance, and if they would recommend a trial of SCS treatment to someone
      else with similar gastrointestinal problems.

      All patients will be evaluated with the hospital anxiety and depression scale (HADS) and a
      modified version of the gastrointestinal symptom rating scale for IBS (GSRS-IBS).
    

Intervention name(s): Spinal Cord Stimultion (SCS); Spinal cord nerve stimulation
Intervention type(s): Device; Device
Intervention description(s): Electric stimulation of the spinal cord
Other intervention name(s): Quad-plus®, Medtronic Inc., MN, USA
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Spinal cord stimulation
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Spinal cord stimulation; Irritable bowel syndrome; Abdominal pain; Diarrhea