Hypothesis / aims of study
Sacral neuromodulation (SNM) has recently been used as an alternative treatment modality in patients with refractory overactive bladder (OAB), interstitial cystitis (IC), non-obstructive chronic urinary retention (NOUR) and fecal incontinence (FI). However, data derived from comparisons of different parameters of patient satisfaction are limited. In this cohort, we aimed to report the effectiveness, quality of life (QoL) changes and patient-reported outcomes (PROs) as well as safety of SNM in different patient groups.
Study design, materials and methods
Between March 2015 and December 2018, patients who received SNM were retrospectively reviewed. Patients suffering from intractable urinary voiding dysfunctions were enrolled including OAB and NOUR. All patients had failed conservative and medical treatments. Pretreatment disease-specific symptoms were documented, and generic QoL questionnaires were administered. After inital test phase in which success was considered as a minimum of 50% improvement in one of the voiding diary parameters (frequency, voided volume, incontinence episodes, number of catheterization), a permanent pulse generator was implanted .We conducted the survey to evaluate the HRQOL using the Short Form 36 health survey (SF-36) version 2. SF-36 evaluates the following 8 physical and mental health areas: physical functioning (PF), physical role functioning (RP), bodily pain (BP), general health (GH), vitality (VT), social role functioning (SF), emotional role functioning (RE), and mental health (MH) We assessed subjective satisfaction rate of the patients with the Patient Global Impression of Improvement (PGI-I) questionnaire. Other objective variables, such as maximum pad number and post void residual urine volume were also evaluated.
A total 23 subjects (17 females and 6 males) with average age of 38 years old (21–55 years old) were implanted tined lead electrode (Medtronic, Minnetonka, MN). The median test phase was 25 days (10-33 days) and median follow-up period was 17 months (5-34months). OAB was diagnosed in 12 and NOUR in 11 patients. Sustained benefit was observed in 58.3% (n = 7) patients with OAB and in 54.4% (n= 6) patients with UR. Overall, SNM was successful in 18 patients but failed in 5. Most common adverse effects were the pain in IPG site and wound infection. Overall success rate was 56.5%. The median outcome on the PGI-I scale was 2 “much better,” according to patients who responded. In the OAB group; three mean SF-36 scales (physical function, vitality , and mental health) significantly improved after treatment when comparing to the NOUR group (p=0.034, p=0.045, p=0.024 respectively).
Interpretation of results
Our results showed similar efficacy and safety of SNM in patients with OAB and NOUR. We had slightly lower overall success rates when compared to literature, however our patients had complex histories and multiple comorbidities. Nevertheless, the success in both groups were comparable to other cohorts. Patients who had OAB symptoms seemed to have better score improvements in the mental aspect of HRQOL at the median 17 months follow-up. Their satisfaction is mainly reflected as less requirement to additional medications for symptom control. Similarly, SNM led to improvement in physical and cognitive performance of patients, too.