Sacral neuromodulation compared with injection of bulking agents for faecal incontinence following obstetric anal sphincter injury – a randomized controlled trial

Abstract Aim The purpose of this trial was to compare the effectiveness of sacral neuromodulation ( SNM ) with a submucosal injection of collagen (Permacol®) in women with faecal incontinence following obstetric anal sphincter injury ( OASIS ). Method This single‐blinded randomized controlled trial at two hospital units in Norway included women with faecal incontinence following OASIS . Eligible women who had had a successful percutaneous nerve evaluation were randomly assigned to SNM or Permacol®. The primary outcome was the difference in the St Mark's incontinence score between baseline and 6 months. Secondary outcomes were changes in the disease‐specific quality of life ( FIQL ) and urinary incontinence ( ICIQ ‐ UI ‐ SF ) scores. Results Fifty‐eight women were randomly assigned to SNM ( n = 30) and Permacol® ( n = 28). The reduction in the St Mark's score between baseline and 6 months was 11.2 ( SD 5.3) in the SNM group vs 2.3 ( SD 5.0) in the Permacol® group, resulting in a difference of 8.9 (95% CI : 6.1–11.7, P < 0.0001). The differences in the four scales of FIQL (lifestyle, coping, depression, embarrassment) were 0.90 (95% CI : 0.50–1.30, P < 0.001), 1.05 (0.62–1.47, P < 0.001), 0.52 (95% CI : 0.16–0.87, P = 0.005) and 0.95 (95% CI : 0.50–1.40, P < 0.001), respectively, in favour of SNM . The difference in the ICIQ ‐ UI ‐ SF was 5.0 (95% CI : 1.97–8.02, P = 0.002) in favour of SNM . There were nine minor adverse events in the SNM group compared with seven in the Permacol® group ( P = 0.77). Conclusion SNM was superior to Permacol® in terms of reduction of St Mark's score, ICIQ ‐ UI ‐ SF and the change of the FIQL in women with faecal incontinence following OASIS .