Efficacy of sacral neuromodulation on urological diseases: a multicentric research project

Sacral neuromodulation has been used as a safe, effective treatment option for patients with lower urinary tract dysfunction (LUTD). Several clinical studies demonstrated its positive effects on refractory urge incontinence, non-osbstructive urinary retention, urgency frequency syndrome, as well as on other non- urological disorders, such as fecal incontinence and chronic constipation. The aim of this research project was to evaluate the efficacy and safety of sacral neuromodulation on the management of LUTD refractory to the standardized first line treatment options.

We retrospectively collected and evaluated data from patients undergoing sacral neuromodulations between September 2001 and November 2010 in 4 Urological Centres of North-East Italy. The patients were affected by Overactive Bladder Syndrome (OAB), Urinary Retention (UR), Fecal Incontinence (FI), Constipation (CO), Chronic Pelvic Pain (CPP). All the patients were evaluated with voiding diaries, before and after implantation.Patients included in the present evaluation were followed up in a network of 4 Italian urological centres, which participate to in the Italian Clinical Service project - a national urological database and medical care project aiming at describing and improving the use of implantable urological devices in the Italian clinical practice. Continuous normally distributed variables were reported as the mean value ± standard deviation (SD). Continuous non-normally distributed variables were presented as the median values and an interquartile range (IQR). The t-test and Wilcoxon test were used to compare continuous variables, as appropriate. A two-sided p <0.05 was considered statistically significant.

Overall, 157 patients underwent implantation of sacral neuromodulator during the period under review. Eighty-three out of 157 (53%) patients complained of OAB; 52 (33%) of UR; 5 (3%) of faecal incontinence; 4 (2%) of chronic constipation; 12 (8%) of CPP. The median follow- up was 11 months (IQR 1 - 91 months). In patients treated for OAB, we documented a statistically significant reduction in the mean number of: incontinence episodes/die, pads/die, daily micturitions, nocturnal micturitions and global micturitions. In patients treated for UR, we observed a statistically significant reduction in the mean post- voiding residual volume and in the number of self catheterization. Interpretation of results: It is difficult to translate into quantifiable data the subjective perception of improvement of the symptoms expressed by the patients, as they are frequently subjective perceptions, not always numeric data. This subjective perception makes it difficult to the clinician to evaluate the real outcomes of this procedure, and makes it difficult to achieve a complete follow-up.

This multicenter research project confirmed the midterm safety and effectiveness of sacral neuromodulation in the treatment of refractory overactive bladder syndrome and urinary retention, showing high cure rates and low complication rates.