Risk Factors Associated with Lead Migration Requiring Revision in Dorsal Root Ganglion Stimulation

Physical Therapy Considerations and Recommendations for Patients Following Spinal Cord Stimulator Implant Surgery

OBJECTIVES

Spinal cord stimulation (SCS) is an established therapy option in interventional pain medicine. Recent advances in technology have allowed for greater compliance with treatment and improved efficacy in pain control. This article was proposed to fill the gap in the literature addressing this specific patient population and to facilitate further research. Even though there is a lack of consensus among societies and experts on exact parameters of physical therapy (PT) considerations and postoperative limitations in patients with SCS, we propose rehabilitative care for this population should be standardized. As the number of patients with SCS implants grow, it is vital to understand how to appropriately approach patients with implantable devices when additional treatments such as PT are prescribed.

MATERIALS AND METHODS

A literature search was performed on the use of PT following SCS implantation. Presently, there is no literature to date which addresses the use of PT in this patient population. The lack of data is the largest hurdle in the creation of formal SCS therapy guidelines. The authors therefore proposed recommendations for rehabilitation based upon a detailed understanding of SCS hardware alongside well-studied physiotherapy concepts.

RESULTS

Considerations when initiating PT in the SCS patient population should include: 1) biomechanics and quality of SCS output; 2) therapeutic exercise and spinal manipulation in association with risk for lead migration and fracture; 3) the application of therapeutic modalities and risk for injury to the patient and/or damage to the SCS componentry; and 4) integration of a biopsychosocial, person-centered approach.

CONCLUSIONS

PT treatment protocol in patients with a recently implanted SCS device should be person-centered addressing individual needs, values, and goals. Further research is needed to fully appreciate the impact of an interprofessional approach to management of SCS patients, particularly following stimulator implantation.

Superior Cluneal Nerve Stimulator Lead Displacement to the Thigh: A Case Report and Management Recommendations

CASE

An 82-year-old man with a history of lumbar spinal stenosis and prior laminectomy presented with chronic lower back pain and was treated with placement of bilateral superior cluneal nerve stimulators. At the 2-week follow-up, the patient reported loss of efficacy and new-onset paresthesia of the left lower extremity. Fluoroscopic evaluation revealed lead breakage and distal migration of the left-sided stimulator lead to the left anteromedial thigh.

CONCLUSION

Lead breakage and migration remains a challenge in peripheral nerve stimulation. This report illustrates the case of a nerve stimulator lead breakage and migration resulting in treatment failure and new-onset sensory disturbance.

Alternative Dorsal Root Ganglion Neuromodulation Electrode Implantation: A Report of 2 Cases with 3 Different Techniques

BACKGROUND AND STUDY AIMS

 The traditional percutaneous placement of dorsal root ganglion (DRG) electrodes may not be eligible for every patient. In this tertiary spine surgery and interventional pain therapy center, alternative neurostimulation implantation techniques were developed and applied where standard percutaneous approaches failed or were contraindicated.

CASE PRESENTATION

 Three alternative implantation techniques can be used: (1) open surgical placement of DRG leads, (2) two-lead insertion via a lateral to medial transforaminal approach (level L3), and (3) percutaneous approach with two leads close to the spinal nerves L4 (peripheral nerve stimulation).

RESULTS

 The placement of the leads occurred without complications and resulted in similar expected outcomes as with the common percutaneous technique with long-term stable pain suppression at 7 months and 1 year.

CONCLUSIONS

 In patients in whom the DRG cannot be approached by the standard percutaneous approach, at least three alternatives may be used in experienced hands resulting in stable pain suppression of similar magnitude.

Lead migration and fracture rate in dorsal root ganglion stimulation using anchoring and non-anchoring techniques: A multicenter pooled data analysis

INTRODUCTION

Dorsal root ganglion stimulation (DRG-S) is a neuromodulation technique introduced in the last decade with evolving implant methods. Initial prospective research found low incidences of lead migration and lead fracture with DRG-S. However, several recent studies have highlighted high lead migration and lead fracture rates with DRG-S. We investigated the influence of lead anchoring on migrations and fractures.

METHODS

We performed a retrospective review between 2016 and 2020 of individuals implanted with DRG-S leads by 4 experienced implanters. The implanters independently changed their standard practice regarding lead anchoring over time, with opposing trends (no anchoring > anchoring, anchoring > no anchoring). We compared lead migration and lead fracture rates between anchored and unanchored DRG-S leads in the entire study cohort. Cox regression was performed on lead migration and fracture distributions.

RESULTS

We included 756 leads (n = 565 anchored and n = 191 unanchored) from 249 patients. In unanchored leads, migration occurred in 16 leads (8.4%) from 13 patients (21.0%). In anchored leads, migration occurred in 8 leads (1.4%) from 5 patients (2.7%). Fracture in unanchored leads occurred in 6 leads (3.1%) from 6 patients (9.7%). Fractures in anchored leads occurred in 11 leads (1.9%) from 9 patients (4.8%). The migration survival distributions for the anchored and unanchored leads were statistically significantly different (p < 0.01) with decreased survival for unanchored leads (hazard ratio = 5.8, 95% confidence interval [CI] = 2.2-15.5).

DISCUSSION

We found that anchoring DRG-S leads significantly reduces lead migration when compared to leads placed without an anchor. There was no significant difference in fracture rate between anchored and unanchored leads.

Utility of Electrical Neuromodulation for Treating Chronic Pain Syndromes in the Pediatric Setting: A Systematic Review

OBJECTIVES

Chronic pain syndromes in children can carry significant threats to psychological well-being, opioid overuse, functional impairments, and severe disability. While several high-level studies, almost exclusively in adults, have demonstrated the utility of implantable electrical neuromodulation systems for treating various chronic pain syndromes, there exists a paucity of pediatric-specific evidence. Unfortunately, evidence and practice patterns established from adults may not be fully translatable to children given differences in disease manifestations and anatomical variances.

MATERIALS AND METHODS

We performed a systematic review using conventional PRISMA methodology to identify studies reporting use of implantable electrical neuromodulation systems in children. The primary outcome parameters collected were analgesic relief and functional benefits. Additionally, previous interventions attempted, neuromodulation parameters, and limitations were collected as reported.

RESULTS

A total of 11 studies was identified, which described 19 patients who were refractory to multidisciplinary pain management strategies. The cohort was mostly adolescent (18/19), suffered from CRPS (14/19), and received SCS (17/19). Nearly all patients, both those with CRPS (13/14) and non-CRPS conditions (4/4), reported significant pain relief and functional recovery following neuromodulation. There were no severe complications reported; limitations included suboptimal benefit or loss of analgesia (3/19), lead or device revision (3/19), and subcutaneous infection (1/19), all of which were congruent with adult outcomes.

CONCLUSION

There exist children with chronic pain refractory to standard of care approaches who could be considered for neuromodulation interventions. The existing data, which was limited and from a low tier of evidence, suggest that these interventions are relatively safe and provide meaningful pain reduction and functional improvements. While not previously reported, we recommend careful consideration of the pubertal growth spurt prior to device lead placement-if reasonable and appropriate-given the possibility of inferior lead migration with physiologic growth in patients with SCS devices or foraminal extrusion in patients with dorsal root ganglion stimulation devices.