The history of sacral neuromodulation in Canada

Understanding a decade of safety reporting for sacral neuromodulation in the Food and Drug Administration Manufacturer and User Facility Device Experience database

INTRODUCTION

Over 350 000 sacral neuromodulation (SNM) devices have been implanted since approval by the Food and Drug Administration (FDA) in 1998. SNM technology and clinical applications have evolved, with minimal safety updates after initial trials. We aim to provide an updated overview of real-world SNM safety. These insights will guide informed consent, preoperative counseling, and patient expectation-setting.

MATERIALS AND METHODS

The FDA Manufacturer and User Facility Device Experience (MAUDE) database is a repository for medical device safety reports. We performed MAUDE categorical (1/1/98-12/31/10) and keyword (1/1/11-9/30/21) searches for "Interstim." A random sample of 1000 reports was reviewed and categorized by theme. To corroborate our MAUDE database analysis, a legal librarian searched the Public Access to Court Electronic Records (PACER) database, as well as Bloomberg Law's dockets database for all lawsuits related to SNM devices.

RESULTS

Our search of the MAUDE database returned 44 122 SNM-related adverse events (AEs). The figure illustrates the prevalence of event categories in the random sample. The largest proportion of reports (25.6%) related to a patient's need for assistance with device use, followed by loss/change of efficacy (19.0%). Interestingly, a fall preceded issue onset in 32% of non-shock pain, 30% of lead/device migration, and 27% of painful shock reports. Our legal search revealed only four lawsuits: one for patient complications after an SNM device was used off-label, one case of transverse myelitis after implant, one for device migration or poor placement, and the fourth claimed the device malfunctioned requiring removal and causing permanent injury.

CONCLUSIONS

This review confirms the real-world safety of SNM devices and very low complication rates as seen in the original clinical trials. Our findings indicate that 43.2% (95% confidence interval 40.1%-46.3%) of SNM "complications" are not AEs, per se, but rather reflect a need for improved technical support or more comprehensive informed consent to convey known device limitations to the patient, such as battery life. Similarly, the number of lawsuits is shockingly low for a device that has been in the market for 24 years, reinforcing the safety of the device. Legal cases involving SNM devices seem to relate to inappropriate patient selection-including at least one case in which SNM was used for a non-FDA approved indication-lack of appropriate follow-up, and/or provider inability to assist the patient with utilizing the device after implantation.

Urologist-perceived barriers and perspectives on the underuse of sacral neuromodulation for overactive bladder in Canada

INTRODUCTION

An estimated 18% of Canadians have overactive bladder (OAB), with approximately 24% of those reporting difficulty adhering to pharmacotherapy. To date, there has been no investigation into barriers facing sacral neuromodulation (SNM) as treatment for OAB in Canada.

METHODS

Current Canadian Urological Association members were invited to participate in an anonymous survey. Data collected included open-ended and Likert scale responses addressing barriers to referral for SNM. Qualitative analysis used a Theoretical Domains Framework (TDF), while quantitative responses are reported using descriptive statistics.

RESULTS

A response rate of 20.4% (n=142) was obtained. Most respondents believed SNM was underused (n=82, 57.7%) compared to only 6.3% (n=9) who believed it was used adequately. The most commonly cited reasons for not offering SNM were lack of availability (n=85, 59.9%), expertise (n=49, 34.5%), and funding (n=26, 18.3%). Participants were neutral regarding confidence to appropriately recommend SNM to patients (median 3, interquartile range [IQR] 2-4) and were not confident to manage patient care and issues related to SNM devices (median 2, IQR 1-3). On thematic analysis using the TDF, the most prevalent barriers to SNM care were related to infrastructure and resources. A lack of trained experts and lack of knowledge related to SNM use were also commonly identified barriers.

CONCLUSIONS

In this first study exploring urologist-perceived barriers to SNM referral for medically refractory OAB in Canada, urologists acknowledge that SNM implantation is underused but did not feel confident in recommending SNM appropriately. A lack of trained experts and poor funding were also identified as major barriers to SNM referral.

Systematic Literature Review and Meta-Analysis of Sacral Neuromodulation (SNM) in Patients with Neurogenic Lower Urinary Tract Dysfunction (nLUTD): Over 20 Years' Experience and Future Directions

INTRODUCTION

Sacral neuromodulation (SNM) has been used in carefully selected patients with neurogenic lower urinary tract dysfunctions (nLUTD) for over two decades.

METHODS

The aim of the current work was to perform a systematic literature review and meta-analysis of studies reporting the safety and effectiveness of SNM in patients with nLUTD (neurogenic detrusor overactivity, non-obstructive urinary retention, or a combination of both). For this purpose a systematic literature research was conducted using Embase (OvidSP), MEDLINE (OvidSP), MEDLINE In-Process Citations & Daily Update (OvidSP), MEDLINE (OvidSP) e-Pub ahead of print, Cochrane Central Register of Controlled Trials (CENTRAL), NIH Clinicaltrials.gov, and WHO International Clinical Trials Registry Platform (ICTRP) between 1998 and March 2020, supplemented by a hand search.

RESULTS

Forty-seven studies were included in the systematic literature review. Twenty-one studies comprising a total of 887 patients were included in the meta-analysis of test SNM. The pooled success rate of SNM test stimulation was 66.2% (95% CI 56.9-74.4). Depending on neurogenic conditions test success rates varied greatly. Twenty-four studies with a total of 428 patients were included in the meta-analysis of permanent SNM. The success rate of pooled permanent SNM was 84.2% (95% CI 77.8-89.0). Among the identified studies, the most common adverse events (AEs) were loss of effectiveness, infection, pain at implant site, and lead migration with AE rates of 4.7%, 3.6%, 3.2%, and 3.2%, respectively. Limitations entail lower level of evidence (Oxford classification 3-4) of included studies, significant risk of bias, small sample sizes in some studies, the inclusion of retrospective case series, substantial between-study heterogeneity, heterogeneous patient populations, insufficient disease classification, and variations in terms of outcome parameters as well as techniques. Furthermore, long-term data are limited.

CONCLUSION

This meta-analysis supports not only the benefits of permanent SNM for various nLUTDs but also high overall success rates, similar to idiopathic patients. Current data of the analyzed studies showed that SNM is safe for these patients. However, more vigorous studies and/or registries are needed before definitive conclusions can be drawn.