Abdominal Versus Standard Placement of the Sacral Nerve Stimulator Implantable Pulse Generator

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.

Pocket pain, does location matter: a single-centre retrospective study of patients implanted with a spinal cord stimulator

OBJECTIVES

Spinal cord stimulation (SCS) is an effective therapy for alleviating pain but reported complication rates vary between healthcare centers. This study explored the prevalence of pain associated with Implantable Pulse Generators (IPGs), the component that powers the SCS system.

METHODS

This was a retrospective, single site study analyzing data from 764 patients who had a fully implanted SCS between September 2013 and March 2020. Demographic data were collected together with IPG site and type, patient reported presence of IPG site pain, revisions, explants and baseline scores for neuropathic pain (using the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs questionnaire). Data were statistically analyzed by one-way analysis of variance, independent sample t-tests, X² tests of independence and logistic regression modeling.

RESULTS

IPG site pain occurred in 127 (17%) of 764 patients. These patients had higher baseline neuropathic pain scores than those who reported no IPG site pain. This complication was more common in females than males. The lowest rates of IPG site pain occurred after posterior chest wall placement and the highest rates occurred after abdominal implants. 7% of patients had revision surgery for IPG site pain (n=55) and 10 of 95 explanted patients stated that IPG site pain was a secondary influencing factor.

CONCLUSIONS

These findings suggest that IPG site pain is a common complication, contributing to SCS revisions and explantation. This study shows that anatomical factors and baseline characteristics of individual patients may contribute to IPG site pain and indicates that exploration of potential factors leading to IPG revision is required.