Neuromodulation Implantation Settings Variation for Overactive Bladder

Intermittent Versus Continuous Stimulation in Bilateral Sacral Neuromodulation for Overactive Bladder

Participants receiving neuromodulation treatment for overactive bladder symptoms will be routinely fitted with an impulse generator. However, the setting on the impulse generator will be set to either intermittent or continuous stimulation. Participants will complete voiding logs and surveys for a month. Battery life will be interrogated.After a one week period were the device is turned off, the impulse generator will be turned to the opposite setting (intermittent or continuous) and the one month period will be repeated. Again, voiding logs, surveys, and battery life will be collected.

The purpose of this project is to investigate the outcomes of intermittent versus continuous stimulation in patients treated with sacral neuromodulation (SNM) for refractory overactive bladder (OAB) syndrome. In addition, the potential for an improved battery life with intermittent stimulation will be quantified.

The objective of this project is to investigate the outcomes of intermittent versus continuous stimulation in patients treated with sacral neuromodulation (SNM) for refractory overactive bladder (OAB) syndrome. In addition, the potential for an improved battery life with intermittent stimulation will be quantified. Manufacturers recommended settings for newly implanted impulse generators (IPG); however, no standardized recommendations exist for further adjustments. Quality studies examining IPG parameters are lacking, partly due to the numerous setting variables, which can result in a multitude of permutations. When programming an IPG, an option for cycling simulation (16 seconds on, 8 seconds off) is available. It is theorized that because of a "carryover" effect, symptom relief will continue despite the stimulator being off. The potential benefit of the intermittent stimulation is an improved battery life, which may translate into a less frequent need for reimplantation with less morbidity. Participants receiving neuromodulation treatment for overactive bladder symptoms will be routinely fitted with an impulse generator in a pre-study phase. Patients who experience significant symptomatic improvement will receive a full bilateral sacral neuromodulator implantation and will be randomized to either intermittent or continuous stimulation. Participants will fill out voiding logs and surveys over a 12 week period. At that point, a one-week washout period during which the neuromodulator will be turned off. The impulse generator will then be turned to the alternate setting (intermittent or continuous) and the 12 week period will be repeated. Questionnaires and voiding diaries will be collected at each clinic visit. In total, subject participation will last approximately 25 weeks after full implantation of the bilateral leads and pulse generator.

Inclusion criteria:

• patients age 18 to 85 with overactive bladder symptoms refractory to behavioral and anticholinergic therapy, detrusor overactivity on urodynamic study, surgically fit with ability to complete study forms, use patient programmer, and return for follow-up.

Patients must have attempted and failed noninvasive therapy for overactive bladder symptoms for at least 6 months prior to enrollment; previous treatments will be recorded. In addition, patients must be fluent in the English language to complete informed consent paperwork and study questionnaires.

Exclusion criteria:

• dementia,
• neurological conditions (spinal cord injury, multiple sclerosis),
• non-English speaking,
• acute urinary tract infection,
• primary pelvic pain,
• pregnancy or breast-feeding,
• urinary retention (postvoid residual greater than 100mL),
• history of bladder cancer in the past 5 years,
• history of nephrolithiasis or ureterolithiasis,
• anticoagulant therapy,
• implanted pacemaker/defibrillator, or
• anticipated need for future MRI.