2.  Sacral nerve stimulation is effective in the treatment of faecal incontinence.  However, 15 to 30% of patients fail to respond post-implantation for unknown reasons.  No factors are predictive of secondary failures. PREDICTIVE FACTORS FOR SUCCESSFUL SACRAL NERVE STIMULATION IN THE TREATMENT OF FAECAL INCONTINENCE: LESSONS FROM A COMPREHENSIVE TREATMENT ASSESSMENT Anne-Laure Roy, MD; Guillaume Gourcerol, MD, PhD; Jean-Francois Menard, MD; Francis Michot, MD, PhD; Anne-Marie Leroi, MD, PhD, and Valérie Bridoux, MD, PhD

3. Aims of the study 1. Investigate the effect of a three- year sacral nerve stimulation treatment of faecal continence. 2. Identify specific predictive factors from the pre- and per- treatment assessments for the mid- term success of SNS.

4. IMPLANTS 60 Pre-implantation assessment

5. IMPLANTS 45 Post-implantation assessment

6. Effect of sacral nerve stimulation at the 3 year follow-up 60 patients 33 patients Successful outcome ITT = 31.7% PP = 55% 22 patients Unsuccessful outcome ITT = 24.7% PP = 36.7% 5 missing severity score 12 patients Device failures 7 patients explanted/ switched off device 3 patients withdrew from study

7. Why did some patients show no improvement post- implantation? Predictive factors for the mid-term success of sacral nerve stimulation