Programming InterStim™ for faecal incontinence

Abstract

Sacral nerve stimulation (SNS) for faecal incontinence (FI) is achieved by implanting a pulse generator attached to a tined lead with individually programmable electrodes. Our aim was to establish whether the 'ideal' programme for the treatment of FI has been used most commonly. We also wished to determine whether re-programming changed the symptom severity scores. The following data were extracted from our SNS patient database: the frequency with which each programme was used, the length of time it was effective for, the number of months from implantation that the programme was started and the symptom severity scores prior to a change or no change in programme. Thirty-eight patients have had implanted pulse generators inserted since 2004. One hundred and two programme changes were documented in the database. The 'ideal' programme was not most commonly programmed. The common programmes were effective for longest. The electrode furthest from the tip was used in the initial programme only once and the median duration from implantation to the start of a programme including it is 13 months. Symptom severity scores were significantly higher in patients who required re-programming than in those whose programme remained unchanged. In our patients the 'ideal' programme was not the programme used most frequently, nor for the longest duration. The theoretical migration of the tined lead inwards with time is upheld by our results. Patients who feel the sensation of SNS perianally have lower symptom scores than those who do not and who require re-programming.