Axonics Sacral Neuromodulation System for Treating Refractory Overactive Bladder: A NICE Medical Technologies Guidance

Sacral neuromodulation in the management of chronic pelvic pain: A systematic review and meta-analysis

INTRODUCTION

Sacral neuromodulation (SNM) is a treatment approved for use in several conditions including refractory overactive bladder (OAB) and voiding dysfunction. Chronic pelvic pain (CPP) is a debilitating condition for which treatment is often challenging. SNM shows promising effect in patients with refractory CPP. However, there is a lack of clear evidence, especially in long-term outcomes. This systematic review will assess outcomes of SNM for treating CPP.

METHODS

A systematic search of MEDLINE, Embase, Cochrane Central and clinical trial databases was completed from database inception until January 14, 2022. Studies using original data investigating SNM in an adult population with CPP which recorded pre and posttreatment pain scores were selected. Primary outcome was numerical change in pain score. Secondary outcomes were quality of life assessment and change in medication use and all-time complications of SNM. Risk of bias was assessed using the Newcastle Ottawa Tool for cohort studies.

RESULTS

Twenty-six of 1026 identified articles were selected evaluating 853 patients with CPP. The implantation rate after test-phase success was 64.3%. Significant improvement of pain scores was reported in 13 studies; three studies reported no significant change. WMD in pain scores on a 10-point scale was -4.64 (95% confidence interval [CI] = -5.32 to -3.95, p < 0.00001) across 20 studies which were quantitatively synthesized: effects were maintained at long-term follow-up. Mean follow-up was 42.5 months (0-59). Quality of life was measured by RAND SF-36 and EQ-5D questionnaires and all studies reported improvement in quality of life. One hundred and eighty-nine complications were reported in 1555 patients (Clavien-Dindo Grade I-IIIb). Risk of bias ranged from low to high risk. Studies were case series and bias stemmed from selection bias and loss to follow-up.

CONCLUSION

Sacral Neuromodulation is a reasonably effective treatment of Chronic Pelvic Pain and significantly reduces pain and increases patients' quality of life with immediate to long-term effects.

Trends in volumetric-energy efficiency of implantable neurostimulators: a review from a circuits and systems perspective

This paper presents a comprehensive review of state-of-the-art, commercially available neurostimulators. We analyse key design parameters and performance metrics of 45 implantable medical devices across six neural target categories: deep brain, vagus nerve, spinal cord, phrenic nerve, sacral nerve and hypoglossal nerve. We then benchmark these alongside modern cardiac pacemaker devices that represent a more established market. This work studies trends in device size, electrode number, battery technology (i.e., primary and secondary use and chemistry), power consumption and longevity. This information is analysed to show the course of design decisions adopted by industry and identifying opportunity for further innovation. We identify fundamental limits in power consumption, longevity and size as well as the interdependencies and trade-offs. We propose a figure of merit to quantify volumetric efficiency within specific therapeutic targets, battery technologies/capacities, charging capabilities and electrode count. Finally, we compare commercially available implantable medical devices with recently developed systems in the research community. We envisage this analysis to aid circuit and system designers in system optimisation and identifying innovation opportunities, particularly those related to low power circuit design techniques.

Axonics Sacral Neuromodulation System for Treating Refractory Overactive Bladder: A NICE Medical Technologies Guidance

The Axonics sacral neuromodulation (SNM) system can be used by people with refractory overactive bladder (OAB) to reduce symptoms of urge urinary incontinence and urinary frequency, where conservative treatments have failed or are not suitable. It is the first system for this indication that makes use of a rechargeable battery to prolong the lifespan of the implanted device, with the potential advantage of reducing the frequency of surgical replacement procedures and associated complications. We describe the evidence considered by the UK National Institute of Health and Care Excellence (NICE) in their evaluation of this evidence, supported by Cedar Healthcare Technology Research Centre. Two observational studies provided descriptive data that suggested improvement in control of symptoms after implantation of the Axonics SNM system; however, there was no peer-reviewed evidence that directly compared rechargeable and non-rechargeable SNM systems. In the absence of long-term data, economic modelling relies on the accuracy of battery life estimates. The evidence supports the case for adopting the Axonics SNM system for treating refractory OAB, when conservative treatment or treatment with medicines has not worked. This conclusion is consistent with other relevant NICE guidelines. Use of Axonics SNM technology in the UK National Health Service (NHS) is associated with a potential cost saving of £6025 per person over a 15-year period when compared with an equivalent non-rechargeable SNM system, assuming the claimed battery life estimate (a minimum of 15 years) is accurate. The cost savings are estimated to start around 6 years after implantation.