Sacral neuromodulation (SNM) is a widespread therapy for refractory lower urinary tract symptoms (LUTS) and faecal incontinence. Patients are separately managed by the Urology department (UD) or the Colorectal surgery department (CRD). Additionally, history taking is usually directed to discipline specific symptoms, with urologists focusing on LUTS and colorectal surgeons focusing on bowel dysfunctions. The aim of this interim-analysis was to report the prevalence of baseline concomitant bowel symptoms and urinary symptoms in patients consulting the UD and CRD respectively. Secondly, we aimed to explore the efficacy of SNM on non-discipline specific patient reported outcome measures (PROMs) in the patient groups of each medical department.

A single centre prospective study was held between February 2018 and March 2020. Patients planned for a 2 staged tined lead procedure using the InterStim II® system, consulting the UD or  the CRD for LUTS and/or bowel dysfunctions were enrolled. Approvement from the Ethics Committee of the University Hospital of Ghent was obtained (EC/2018/0244). The decision to proceed from first stage to definitive implant was based on the assessment of bladder or bowel diaries and patient reported satisfaction. Independently from the treating physician’s advice for implant, all patients were asked to complete a battery of Dutch PROMs on an online survey platform. The survey was completed at different time points: at baseline, at the end of the test phase, 1 month, 6 months and 12 months after the definitive implant. The survey consisted of the following questionnaires: the male and female International Consultation on Incontinence Questionnaire (ICIQ-MLUTS and ICIQ-FLUTS), the ICIQ on urinary Incontinence short form (ICIQ-UI-SF), the ICIQ-Bowel (ICIQ-B), the Wexner Score for faecal incontinence and the Cleveland Constipation Score (CCS). For each scoring system, a higher score marked a higher grade of symptoms. Additionally, patients were asked if they had urinary symptoms or bowel symptoms (‘yes or no’). Concomitant bother from urinary symptoms (US) and bowel symptoms (BS) had to be rated on a numeric rating scale from 0 (no bother at all) to 10 (extremely bothered). For this interim-analysis, only absolute changes between the test phase and baseline PROMs scores were analysed. Patients with missing PROMs were excluded. Descriptive and analytical statistics were performed using SPSS Statistics 25. A paired samples t-test was used for a paired comparison between questionnaires with normally distributed outcome data, using means and standard deviations. A Wilcoxon Signed Rank Test was used for questionnaires with non-normal distributed outcome data, using medians and interquartile ranges. P-values below 0,05 were considered as statistically significant. The analyses were performed for each medical department separately.

Fifty patients were included for analysis, mean (SD) age 52 (15) years, 78% female. The indications for which patients underwent the first stage procedure are listed in table 1. In the UD consulting group, 20/33 (61%) patients reported to have concomitant bowel symptoms, 5 among them with combined incontinence. In the CRD group, 9/17 (53%) reported to have concomitant urinary problems, 4 among them having combined incontinence. The implantation rates for the UD and CRD were 88% (29/33) and 88% (15/17) respectively. After the first stage, UD patients showed a significant reduction in all Urinary PROMS (U-PROMs), as well in all Bowel PROMS (B-PROMs) except from a reduction in the Wexner score. CRD patients showed a significant reduction in all B-PROMs, except from a change in CCS scores. A significant reduction of ICIQ-UI scores and a trend towards significant reduction of US bother scores and ICIQ-FLUTS scores were seen in CRD patients. Outcomes for baseline and test phase PROMs are listed in table 2.

The prevalence of patient reported bowel symptoms in UD patients, undergoing SNM for urinary indications is high. This study demonstrates that apart from a significant decrease in urinary symptoms, also bowel symptoms can significantly improve after the first stage in this UD group. More than half of the patients consulting the CRD undergoing SNM for bowel indications also report to have urinary symptoms. In the CRD patients, the results suggest an improvement in concomitant urinary symptoms as well, after the first stage. However, the sample size of CRD patients might have been too small to discover significant changes in all urinary symptom scores. No comparisons between the two medical departments can be made since the sample sizes of patients were not equal between both groups. These findings however do suggest that in the future, all UD and CRD patients should be counselled on the positive effect of SNM on both urinary and bowel symptoms, regardless of which symptoms are the most prominent. Therefore, in both medical departments a more holistic approach in the assessment of pelvic floor symptoms is needed. Both for baseline screening and evaluating the therapeutic efficacy of SNM, both bladder and bowel diaries and non-discipline specific PROMs should be used.

In both the Urology and Colorectal surgery department the prevalence of concomitant non-discipline specific symptoms is high. UD patients undergoing SNM for urological indications are likely to show an improvement on bowel symptoms as well. Analogously, CRD patients receiving SNM for bowel indications might also show improvement in urinary symptoms. However, in the future, bigger sample sizes are needed to draw more robust conclusions. Nevertheless, a multidisciplinary assessment of pelvic floor symptoms in every SNM candidate is appropriate to deliver optimal holistic care.