SUBsensory Sacral Neuromodulation for InContinence - SUBSoNIC
Research type
Research Study
Full title
RANDOMISED DOUBLE-BLIND EFFICACY AND MECHANISM STUDY OF SUB-SENSORY SACRAL (OPTIMISED) NEUROMODULATION IN ADULTS WITH FAECAL INCONTINENCE
IRAS ID
187783
Contact name
Charles H. Knowles
Contact email
Sponsor organisation
Queen Mary, University of London
Duration of Study in the UK
2 years, 8 months, 31 days
Research summary
A relatively new treatment called sacral neuromodulation (SNM) is now commonly offered to adults suffering with faecal incontinence. Suitable patients include those with faecal incontinence caused by childbirth, surgery, and advancing age. A battery powered unit is implanted into the lower back. This is connected to electrodes which rest on the nerves in the lower spine. This stimulator then continuously sends electrical impulses to the nerves and muscles that control the lower bowel (rectum and anus).The result is improved continence.
Previous studies have reported a great benefit of SNM in some patients. Unfortunately, other patients can have little or no response. We are still unsure about how SNM restores bowel control, and we still do not know with certainty how effective SNM really is. SNM costs on average £10,000 per patient just for the equipment and is not without its risks and side-effects. It is therefore vital that these questions are answered.
This research aims to establish how SNM works and how well SNM works. Patients who meet the current national criteria for SNM will be invited to participate in our trial. They will undergo detailed evaluation of their symptoms. Some patients depending on location will also undergo specialist tests before and after treatment.
These specialist tests will study their anal and rectal function as well as their corresponding brain activity. In contrast to a traditional clinical trial, the design of this trial will allow all patients to receive the treatment. It will be performed in several NHS specialist centres in the UK and in the EU. The trial will include a total of 90 patients. Each patient will participate for just over 1 year, but their SNM treatment will continue thereafter.Summary of results
A treatment called sacral neuromodulation (SNM) is commonly offered to adults experiencing bowel (faecal) incontinence (FI). A battery powered unit is implanted into the lower back in the region of the sacrum (tailbone). This is connected to a specially developed lead with electrodes that rest on the nerves of the lower spine. This stimulator then continuously sends electrical impulses to the nerves and muscles that control the lower bowel (rectum and anus). The aim is to improv bowel control.
Previous studies have reported a great benefit of SNM in some patients, but others have little or no response. The SUBsensory Sacral Neuromodulation for InContinence (SUBSoNIC) trial recruited 39 patients (of 90 intended) who met the current national criteria for SNM. It compared the effect on numbers of weekly FI episodes with the device either on (active) or off (sham) using a special study design called a randomised crossover trial. All participants had the device on and off for 16 weeks in random order (crossing over in the middle). Using stimulation below the level that can be felt (subsensory), both the patients and the research team were unaware of whether the stimulator was on or off (called double blinding).
Due to COVID-19, only 16 patients had complete data for analysis, which was much less than the intended number of 90. The results showed that patients experienced reductions in FI episodes during both on and off periods (i.e. there was a strong placebo effect). However, slightly greater effects were seen during the on period suggesting a possible genuine biological effect of SNM. The study also showed that the way we record symptoms during research trials e.g. with paper bowel diaries needs improvement, as the bowel diaries were not fully completed by some participants. Although this is the first double-blind trial of its kind for SNM, all conclusions must bear in mind the poor recruitment and retention of patients.REC name
London - City & East Research Ethics Committee
REC reference
17/LO/1060
Date of REC Opinion
13 Sep 2017
REC opinion
Further Information Favourable Opinion