Rechargeable occipital nerve stimulator systems: A patient satisfaction study

The IDEAL framework in neurosurgery: a bibliometric analysis

BACKGROUND

The Idea, Development, Exploration, Assessment and Long-term study (IDEAL) framework was created to provide a structured way for assessing and evaluating novel surgical techniques and devices.

OBJECTIVES

The aim of this paper was to investigate the utilization of the IDEAL framework within neurosurgery, and to identify factors influencing implementation.

METHODS

A bibliometric analysis of the 7 key IDEAL papers on Scopus, PubMed, Embase, Web of Science, and Google Scholar databases (2009-2019) was performed. A second journal-specific search then identified additional papers citing the IDEAL framework. Publications identified were screened by two independent reviewers to select neurosurgery-specific articles.

RESULTS

The citation search identified 1336 articles. The journal search identified another 16 articles. Following deduplication and review, 51 relevant articles remained; 14 primary papers (27%) and 37 secondary papers (73%). Of the primary papers, 5 (36%) papers applied the IDEAL framework to their research correctly; two were aligned to the pre-IDEAL stage, one to the Idea and Development stages, and two to the Exploration stage. Of the secondary papers, 21 (57%) explicitly discussed the IDEAL framework. Eighteen (86%) of these were supportive of implementing the framework, while one was not, and two were neutral.

CONCLUSION

The adoption of the IDEAL framework in neurosurgery has been slow, particularly for early-stage neurosurgical techniques and inventions. However, the largely positive reviews in secondary literature suggest potential for increased use that may be achieved with education and publicity.

One-year outcomes of the ARTISAN-SNM study with the Axonics System for the treatment of urinary urgency incontinence

Aims

Sacral neuromodulation (SNM) is a guideline‐recommended treatment for voiding dysfunction including urgency, urge incontinence, and nonobstructive retention as well as fecal incontinence. The Axonics® System is a miniaturized, rechargeable SNM system designed to provide therapy for at least 15 years, which is expected to significantly reduce revision surgeries as it will not require replacement as frequently as the non‐rechargeable SNM system. The ARTISAN‐SNM study is a pivotal study designed to treat patients with urinary urgency incontinence (UUI). Clinical results at 1‐year are presented.

Methods

A total of 129 eligible UUI patients were treated. All participants were implanted with a quadripolar tined lead and neurostimulator in a single procedure. Efficacy data were collected using a 3‐day bladder diary, a validated quality of life questionnaire (ICIQ‐OABqol), and a participant satisfaction questionnaire. Therapy responders were defined as participants with ≥50% reduction in UUI episodes compared to baseline. Data were analyzed on all 129 participants.

Results

At 1 year, 89% of the participants were therapy responders. The average UUI episodes per day reduced from 5.6 ± 0.3 at baseline to 1.4 ± 0.2. Participants experienced an overall clinically meaningful improvement of 34 points on the ICIQ‐OABqol questionnaire. All study participants (100%) were able to recharge their device at 1 year, and 96% of participants reported that the frequency and duration of recharging was acceptable. There were no serious device‐related adverse events.

Conclusions

The Axonics System is safe and effective at 1 year, with 89% of participants experiencing clinically and statistically significant improvements in UUI symptoms.

Implantable Pulse Generator Site May Be Associated With Spinal Cord Stimulation Revision Surgeries

BACKGROUND

The use of implantable pulse generators (IPG) for spinal cord stimulation (SCS) in patients with chronic pain has been well established. Although IPG-related complications have been reported on, the association between IPG site and SCS complications has not been well studied.

OBJECTIVE

To investigate whether IPG placement site in buttock or flank is associated with SCS complications and, hence, revision surgeries.

METHOD

A retrospective cohort study was performed that included 330 patients (52% female) treated at a single institution who underwent permanent implantation of an SCS system between 2014 and 2018. Patients ranged between 20 and 94 years of age (mean: 57.54 ± 13.25). Statistical analyses were conducted using IBM SPSS Statistics. Tests included independent samples t test, chi-square test, Mann-Whitney U test, Spearman's rank correlation coefficient, and logistic regression.

RESULTS

There was a total of 93 revision surgeries (rate of 28%), where 71 out of 330 patients (rate of 21.5%) had had at least one revision surgery. Univariate tests demonstrated a significant association between IPG site and revision surgeries (p = 0.028 [chi-square test] and p = 0.031 [Mann-Whitney U test]); however, multivariate logistic regression demonstrated that neither IPG site was more likely than the other to require revision surgeries (p = 0.286).

CONCLUSION

Although this study found a significant association between IPG site and revision surgeries, the effect of IPG site was not found to be predictive. The IPG site likely influences whether a patient will require revision surgery, but further investigation is required to establish this association.

Programming settings and recharge interval in a prospective study of a rechargeable sacral neuromodulation system for the treatment of overactive bladder

AIMS

The RELAX-OAB study is designed to confirm the safety, efficacy, and technical performance of the Axonics r-SNM System, a miniaturized, rechargeable SNM system approved in Europe and Canada for the treatment of bladder and bowel dysfunction. The purpose of this article is to describe study subjects' ability to charge the rechargeable neurostimulator and to document their neurostimulator program settings and recharge interval over time.

METHODS

Fifty-one OAB patients were implanted in a single-stage procedure. These results represent the 3-month charging experience for 48 subjects who completed the 3-month follow-up. Recharge intervals were estimated using therapy stimulation settings and subject experience was evaluated using questionnaires.

RESULTS

Forty-seven of forty-eight (98%) subjects were able to successfully charge their device prior to follow-up within 1-month post-implant. At 3-month post-implant, 98% of subjects were able to charge prior to their follow-up visit. Average stimulation amplitude across all subjects was 1.8 mA (±1.1 mA). A total of 69% of subjects had ≥14-day recharge intervals (time between charging) and 98% of subjects had ≥7-day recharge interval. No charging related adverse events occurred.

CONCLUSIONS

Study subjects were able to charge the Axonics r-SNM System and stimulation settings provided 2 weeks of therapy between recharging for most subjects. Subject satisfaction indicates that subjects are satisfied with rechargeable SNM therapy.

Three month clinical results with a rechargeable sacral neuromodulation system for the treatment of overactive bladder

AIMS

The primary aim of the RELAX-OAB study is to confirm the safety and efficacy of the Axonics r-SNM System, a miniaturized, rechargeable SNM system.

METHODS

A total of 51 OAB patients were implanted in a single-stage implant procedure. These results represent the 3-month outcomes. Subject outcomes were evaluated using 3-day bladder diaries and quality of life questionnaires.

RESULTS

A total of 31 of 34 patients (91%) that responded during an initial trial period ("Test Responders") continued to benefit from therapy with the Axonics r-SNM System at 3-months, defined as symptom improvement of ≥50% reduction in urinary voids or incontinence episodes or a return to <8 voids per day. Subjects who were Test Responders showed a statistically and clinically meaningful improvement in all aspects of quality of life (ICIQ-OABqol). No serious device-related adverse events (SADEs) occurred, and there were no unanticipated adverse events (UAEs). One subject was explanted due to an infection at the implant site and 19.6% of subjects experienced device related adverse events, most notably discomfort due to stimulation, which was resolved with reprogramming.

CONCLUSIONS

The Axonics r-SNM System provides safe and effective SNM therapy with objective improvement in 91% of subjects. The data also demonstrates a significant improvement in all domains of quality of life. This miniaturized, rechargeable system is designed to last 15 or more years and is expected to provide clinical and cost benefits over current non-rechargeable systems by eliminating replacement surgeries.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.