Evaluation of Washout Periods After Dorsal Root Ganglion Stimulation Trial.

OBJECTIVE: Dorsal root ganglion stimulation (DRG-S) is a novel therapy to treat chronic pain. It has shown efficacy when delivered intermittently, suggesting a delayed washout effect exists. To measure the washout period, and to determine whether there are differences in washout times among different types of treated pain, we measured the time for pain to return at the end of the patients' one-week DRG stimulation trials. MATERIALS AND METHODS: Patients who completed a successful DRG-S trial were included. The times until 25% (t25) and 90% (t90) of baseline pain level returned were recorded. The patients were divided into neuropathic, nociceptive, and mixed pain groups for subgroup comparison. t25 and t90 were plotted in the entire cohort and subgroups using reverse Kaplan-Meier plots (failure curves) and compared using a log-rank test. RESULTS: In total, 29 consecutive patients were included. Median t25 and t90 times were 7.1 and 19.5 hours, respectively. Median (interquartile range) times were longest for the nociceptive pain group (n = 17) and shortest for the neuropathic pain group (n = 6), with the mixed-pain group (n = 6) in between (t25: 7.1 [1.7-19.4], 3.40 [1.4-8.4], and 5.7 [0.8-17.6]; t90, 22.0 [10.7-71.0], 7.6 [3.6-19.8], and 20.9 [14.2-31.2], respectively). t90 times differed significantly by pain type (p = 0.040). CONCLUSIONS: This study showed a prolonged washout period after cessation of DRG-S therapy. Washout times vary according to pain type. The observed effects are possibly due to long-term depression of pain signaling and could allow the implementation of alternative stimulation strategies with DRG-S. Further investigations evaluating DRG-S washout times are warranted.

Sacroiliac Joint Denervation-A Novel Approach to Target Sacral Lateral Branches: A Practical Approach.

INTRODUCTION: Sacroiliac joint (SIJ) pain is a relatively common cause of low back pain. Percutaneous radiofrequency (RF) techniques for SIJ are limited to ablation of the posterior SIJ innervation. Different techniques have been described for SIJ radiofrequency ablation, including conventional thermal, cooled RF, pulsed RF, bipolar RF, and specialized tip RF needle (i.e., multi-tined); however, additional costs may limit these applications. METHODS: This new technique for SIJ denervation uses anatomical landmarks and a single RF cannula. Two spinal needles are placed lateral to the posterior S1 and S2 sacral foramina; then, with caudal tilt we get a coaxial view of the sacral bone, we advance an 18-G curved 15-mm active tip RF cannula just lateral to the aligned finder needles. Ablation is performed, and then the RF cannula is retracted 2 cm and ablation is repeated for a total of four lesions. RESULTS: The two spinal needles placed lateral to the posterior sacral foramina S1 and S2 guide the final needle in the posterior aspect of the sacrum, lateral to the sacral foramina, where the lateral sacral branches are located. CONCLUSION: We introduce a cost and time efficient technique to perform radiofrequency ablation of the sacral lateral branches using a single RF needle. This technique utilizes the sacrum's reliable anatomy and angulation and maximizes the surface area of the active tip lesioning. This technique creates a strip lesion lateral to the sacral foramina and reduces time and cost efficacy compared to several of the other techniques and/or commercially available special devices designed for sacroiliac denervation.

Burst Spinal Cord Stimulation as Compared With L2 Dorsal Root Ganglion Stimulation in Pain Relief for Nonoperated Discogenic Low Back Pain: Analysis of Two Prospective Studies.

INTRODUCTION: Chronic discogenic low back pain (CD-LBP) is caused by degenerated disks marked by neural and vascular ingrowth. Spinal cord stimulation (SCS) has been shown to be effective for pain relief in patients who are not responsive to conventional treatments. Previously, the pain-relieving effect of two variations of SCS has been evaluated in CD-LBP: Burst SCS and L2 dorsal root ganglion stimulation (DRGS). The aim of this study is to compare the effectivity in pain relief and pain experience of Burst SCS with that of conventional L2 DRGS in patients with CD-LBP. MATERIALS AND METHODS: Subjects were implanted with either Burst SCS (n = 14) or L2 DRGS with conventional stimulation (n = 15). Patients completed the numeric pain rating score (NRS) for back pain and Oswestry disability index (ODI) and EuroQoL 5D (EQ-5D) questionnaires at baseline, and at three, six, and 12 months after implantation. Data were compared between time points and between groups. RESULTS: Both Burst SCS and L2 DRGS significantly decreased NRS, ODI, and EQ-5D scores as compared with baseline. L2 DRGS resulted in significantly lower NRS scores at 12 months and significantly increased EQ-5D scores at six and 12 months. CONCLUSIONS: Both L2 DRGS and Burst SCS resulted in reduction of pain and disability, and increased quality of life in patients with CD-LBP. L2 DRGS provided significantly increased pain relief and improvement in quality of life when compared with Burst SCS. CLINICAL TRIAL REGISTRATION: The clinical trial registration numbers for the study are NCT03958604 and NL54405.091.15.

Lead migration rate in dorsal root ganglion stimulation using lead anchoring techniques: A follow-up study.

BACKGROUND: Lead anchoring has previously been shown to reduce the rate of dorsal root ganglion stimulation (DRG-S) lead migration. The aim of this study was to assess longer-term follow-up and consistency of lead migration prevention with lead anchoring in a new cohort of patients. METHODS: We performed a retrospective chart review from September 2017 to November 2022 of all patients who had DRG-S implants at our institute to identify the number of lead migrations that occurred over this period. The first cohort consisted of patients reported on in a previous publication (implanted from September 2017 through September 2020) subdivided into unanchored or anchored lead groups. The second cohort consisted of patients implanted during or after October 2020 who were not previously reported on for whom leads were anchored using silastic anchoring only. RESULTS: At the November 2022 data cutoff, in the initial cohort, 8 migrations had occurred in unanchored leads over an average follow-up of 49 months, equating to a migration rate of 9.1% per lead. Patients with anchored leads in the initial cohort experienced 2 migrations over an average follow-up of 38 months (0.7% migration rate per lead). There were no new lead migrations in these groups over the extended follow-up reported here. The migration rate in the new cohort was similar, with 1 migration over an average follow-up of 13 months (0.5% migration rate per lead). CONCLUSION: These results underscore the necessity of anchor placement during DRG-S lead implantation to prevent lead migration.

Dorsal Root Ganglion Stimulation to Treat Chronic Shoulder Pain: A Case Report.

A 67-year-old man presented with severe 9 of 10 intractable pain of the left shoulder joint after arthroplasty and revision surgeries, with associated weakness, atrophy, and limited range of motion in all directions. Dorsal root ganglion stimulation (DRG-S) at the left C4, C5, and C6 levels was used after failed conservative and interventional measures, resulting in significant improvement in pain, function, and quality of life measures through 6 months postimplantation. Larger studies should examine if DRG-S is effective in treating chronic arthritic joint pain as well as chronic postsurgical pain of the shoulder that is not predominantly neuropathic.

Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation: A Proposal for Standardization in Fellowship and Training Programs.

The need to be competent in neuromodulation is and should be a prerequisite prior to completing a fellowship in interventional pain medicine. Unfortunately, many programs lack acceptable candidates for these advanced therapies, and fellows may not receive adequate exposure to neuromodulation procedures. The American Society of Pain and Neuroscience (ASPN) desires to create a consensus of experts to set a minimum standard of competence for neurostimulation procedures, including spinal cord stimulation (SCS), dorsal root ganglion stimulation (DRG-S), and peripheral nerve stimulation (PNS). The executive board of ASPN accepted nominations for colleagues with excellence in the subject matter of neuromodulation and physician education. This diverse group used peer-reviewed literature and, based on grading of evidence and expert opinion, developed critical consensus guides for training that all accredited fellowship programs should adopt. For each consensus point, transparency and recusal were used to eliminate bias, and an author was nominated for evidence grading oversight and bias control. Pain Education and Knowledge (PEAK) Consensus Guidelines for Neuromodulation sets a standard for neuromodulation training in pain fellowship training programs. The consensus panel has determined several recommendations to improve care in the United States for patients undergoing neuromodulation. As neuromodulation training in the United States has evolved dramatically, these therapies have become ubiquitous in pain medicine. Unfortunately, fellowship programs and the Accreditation Council for Graduate Medical Education (ACGME) pain program requirements have not progressed training to match the demands of modern advancements. PEAK sets a new standard for fellowship training and presents thirteen practice areas vital for physician competence in neuromodulation.

Best Practices for Dorsal Root Ganglion Stimulation for Chronic Pain: Guidelines from the American Society of Pain and Neuroscience.

With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion stimulation (DRG-S) has significantly improved the treatment of complex regional pain syndrome (CRPS), and it has broad applicability across a wide range of other conditions. Through funding and organizational leadership by the American Society for Pain and Neuroscience (ASPN), this best practices consensus document has been developed for the selection, implantation, and use of DRG stimulation for the treatment of chronic pain syndromes. This document is composed of a comprehensive narrative literature review that has been performed regarding the role of the DRG in chronic pain and the clinical evidence for DRG-S as a treatment for multiple pain etiologies. Best practice recommendations encompass safety management, implantation techniques, and mitigation of the potential complications reported in the literature. Looking to the future of neuromodulation, DRG-S holds promise as a robust intervention for otherwise intractable pain.

Dorsal root ganglion stimulation for the treatment of joint pain with predominantly nociceptive characteristics: A case series.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S) has recently emerged as a novel therapy in neuromodulation that demonstrated a higher rate of success than spinal cord stimulation (SCS) in a prospective, head-to-head randomized comparative trial to treat complex regional pain syndrome (CRPS) and causalgia. In contrast to SCS, DRG-S also shows promise in treating conditions that are not purely neuropathic such as axial low back pain, which has a prominent nociplastic pain component. It is not known to what extent the effectiveness of DRG-S for such indications is due to effective treatment of the neuropathic pain component versus the effects of DRG-S on mechanical pain. Although rarely studied, reporting outcomes of DRG-S to treat predominantly mechanical/nociceptive pain may help point toward expanding the utility of this therapy. Here, we present five cases of refractory mechanical pain treated with DRG-S. METHODS: A retrospective analysis of all patients who underwent a successful DRG-S trial and implant between September 2017 and September 2021 at our institute was performed. Patients who had intractable joint pain without strong evidence of neuropathic pain were included in this case series. The Budapest criteria for CRPS, the Douleur Neuropathique 4 Questions (DN4) survey, or a definable nerve injury were used to determine the presence of neuropathic pain. Baseline assessments for pain (Numeric Rating Scale [NRS]), function (Oswestry Disability Index [ODI]), quality of life (EuroQol-5 Dimension [EQ-5D]), and other applicable joint surveys were extracted from pre-trial baseline and follow-up appointments. RESULTS: Five patients were identified and included. Patient diagnoses consisted of refractory joint pain of the hip, knee, or ankle. Mean NRS pain scores improved by 74% from 9.2 at baseline to 2.4 at the last follow-up (mean = 28 months post-implant). From baseline to the last follow-up, mean ODI scores improved by 65% from 66 to 23 and EQ-5D scores more than doubled from an average of 0.371 to 0.797. CONCLUSION: This clinical report illustrates the potential utility DRG-S has in treating pain that clinically presents as predominantly refractory mechanical joint pain without a significant neuropathic component. The physiological reasons for our observations may be that DRG-S is able to directly influence the conduction of nociceptive signaling at the DRG and within the spinal cord. Further investigations are warranted to determine if DRG-S is a potential treatment option for chronic mechanical pain.

A prospective study of BurstDR™ spinal cord stimulation for non-operated discogenic low back pain.

INTRODUCTION: Chronic discogenic low back pain (CD-LBP) is caused by degeneration of the disc due to trauma to the annulus or by unprovoked degeneration, resulting in chronic pain. Spinal cord stimulation (SCS) employing the BurstDR™ waveform has been shown to be an effective treatment in a variety of chronic pain conditions. The aim of this prospective case study was to determine the effect of BurstDR™ SCS on pain relief, disability, and patient satisfaction in a population with CD-LBP. METHODS: Seventeen subjects with CD-LBP received a SCS trial with BurstDR™ stimulation. Patients with >50% pain relief after a trial period of 2 weeks were permanently implanted (n = 15). Patients then rated LBP and leg pain using the numeric rating scale (NRS), Oswestry disability index (ODI), patient global impression of change (PGIC), EQ-5D quality of life, and painDETECT for neuropathic pain at baseline following trial, 3, 6, and 12 months after permanent implantation. RESULTS: Treatment with BurstDR™ SCS resulted in significant reduction of LBP as the NRS was reduced from 71.7 ± 7.3 at baseline to 42.5 ± 18.1 at 12 months. Average pain relief at 12 months was 42.5%. In patients with leg pain (n = 8), pain was significantly reduced from 66.9 ± 8.2 to 11.7 ± 10.4 at 12 months. PainDETECT scores for neuropathic pain significantly reduced from 18.9 ± 4.8 at baseline, and 14.8 ± 3.2 at 12 months. Baseline ODI score significantly reduced from 41.2 ± 12.8 to 25.8 ± 8.6 at 12 months. PGIC scores remained low from 2.6 ± 1.6 at 3 months, 2.5 ± 1.0 at 6 months, and 2.5 ± 1.3 at 12 months. EQ-5D-5L rates remained constant from baseline 56.10 ± 23.9 to 68.6 ± 12.9 at 12 months. CONCLUSION: BurstDR™ SCS resulted in significant reduction of back pain, leg pain, and quality of life in patients with CD-LBP and decreased the level of disability and generated positive patient satisfaction scores.

Dorsal Root Ganglion Stimulation as a Salvage Therapy Following Failed Spinal Cord Stimulation.

INTRODUCTION: Spinal cord stimulation (SCS) can provide long-term pain relief for various chronic pain conditions, but some patients have no relief with trial stimulation or lose efficacy over time. To "salvage" relief in patients who do not respond or have lost efficacy, alternative stimulation paradigms or anatomical targets can be considered. Dorsal root ganglion stimulation (DRG-S) has a different mechanism of action and anatomical target than SCS. OBJECTIVES: We assessed DRG-S salvage therapy outcomes in patients who did not respond to SCS or had lost SCS efficacy. MATERIALS AND METHODS: We retrospectively included consecutive patients from 2016 to 2020 who were salvaged with DRG-S after failed SCS trials (<50% pain reduction) or who had lost efficacy after permanent SCS. We compared numerical rating scale (NRS) pain, Oswestry disability index (ODI), health-related quality of life (EuroQol five-dimensions five-level), and oral morphine equivalent (OME) opioid requirements before DRG-S salvage and at patients' last follow-up. RESULTS: A total of 60 patients who had failed SCS were salvaged with DRG-S. The mean age was 56 ± 12 years, and the most common diagnoses were complex regional pain syndrome (n = 24) and failed back surgery syndrome (n = 24). The most common failed modalities included tonic (n = 32), Burst (n = 18), and high-frequency (n = 10) SCS. The median follow-up duration of salvage DRG-S was 34 months. With DRG-S, NRS decreased (8.7 ± 1.2 to 3.8 ± 2.1), and OME declined (median 23 mg to median 15 mg), whereas EuroQol 5D scores increased (0.40 ± 0.15 to 0.71 ± 0.15), and ODI improved (64 ± 14% to 31 ± 18%) (all p < 0.05). CONCLUSIONS: DRG-S can be used in patients with chronic pain who have previously failed to receive persistent benefit from SCS.

Dorsal Root Ganglion Stimulation to Treat Focal Postsurgical and Diffuse Chronic Pain: A Case Report.

Dorsal root ganglion stimulation (DRG-S) is widely accepted for treating focal pain syndromes. We present the case of a 46-year-old woman with severe lumbar radiculopathy with an implanted spinal cord stimulator (SCS) that had lost efficacy. She developed an incisional hernia after undergoing a minimally invasive, extreme lateral interbody fusion and SCS explant. After herniorrhaphy, she presented with severe pain at the T10-T11 dermatomes, which we treated with DRG-S. One-year after lumbar fusion, her refractory lumbar and radicular pain returned, which we ultimately treated with bilateral T12+S1 DRG-S. DRG-S was thus used to successfully treat focal postsurgical and diffuse chronic pain.

Dorsal root ganglion stimulation device explantation: A multicenter pooled data analysis.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S) is a relatively new neuromodulation modality. Therefore, data on long-term device explantation rates is limited. This investigation aimed to assess DRG-S device explantation rates at long-term follow-up. METHODS: We retrospectively reviewed individuals implanted with DRG-S in four pain centers from different continuous periods between April 2016 to September 2020. We recorded patient demographics, diagnoses, duration to explantation or last follow-up, treatment complications, and failure etiologies. RESULTS: A total of 249 patients with 756 leads and a mean 27-month follow-up were included. The mean age was 55 ± 15 years; 148 (63%) were female. Leading diagnoses were CRPS (n = 106, 43%), followed by FBSS (n = 64, 26%), and non-surgical low back pain (n = 23, 9%). The explantation rate was ~2% per year (n = 10 total). At explantation, the average time from implantation was 13 ± 10 months. Six patients were explanted for inadequate pain relief. Two patients were explanted due to device-related complications. One patient was explanted secondary to infection and subsequently reimplanted. Five explanted patients experienced a therapy-related complication before eventual explantation: one transient post-procedural neuritis and pocket site pain, one lead fracture, two lead migrations, and one experienced a fracture, a migration, and pocket site pain. DISCUSSION: This large retrospective study of DRG-S revealed a low therapy-termination rate. The rate of infection leading to explantation was objectively very low at 0.4%. The leading cause of explantation was inadequate pain relief. Explanted patients often had a therapy-related complication. Therefore, minimizing adverse treatment events may reduce ultimate explantation rates.

An Anatomy-Informed, Novel Technique for S1 Dorsal Root Ganglion Stimulation Lead Placement.

OBJECTIVE: A heightened and organized understanding of sacral anatomy could potentially lead to a more effective and safe method of dorsal root ganglion stimulation (DRG-S) lead placement. The aim of this technical note is to describe a standardized access method for S1 DRG-S lead placement. DESIGN: Technical note. METHODS: The described approach utilizes alignment of the lumbosacral prominence and is measurement-based, allowing for standardized sacral access, even when visualization is suboptimal. The medial-to-lateral needle trajectory is designed to limit interaction with the sensitive neural structures and allows for a more parallel orientation of the lead to the DRG and nerve root. CONCLUSIONS: The described technique potentially improves the safety of S1 DRG-S lead placement. The parallel lead orientation to the DRG may also increase efficacy while lowering energy requirements.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Best Practices for Cervical Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on the use of neurostimulation in the cervical region to improve outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for an often-overlooked area of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based upon their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to the present. Identified studies were graded using the US Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the use of cervical neuromodulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be utilized as a guide to assist decision making when clinically appropriate.

Intermittent Dorsal Root Ganglion Stimulation Is as Efficacious as Standard Continuous Dosing in Treating Chronic Pain: Results From a Randomized Controlled Feasibility Trial.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S) is a form of neuromodulation used to treat chronic pain. A spinal cord stimulation (SCS) method with paresthesia-free waveform used in the dorsal columns, burst-SCS, recently demonstrated efficacy using intermittent stimulation, where stimulation is cycled on and off for set durations. Tonic SCS is a paresthesia-based therapy that is ineffective at sub-perception levels and when delivered in a cycled manner. DRG-S also uses a tonic waveform, yet unlike tonic SCS, it is effective at sub-perception levels. This study aimed to determine whether the cycling of stimulation at the DRG could maintain DRG-S efficacy. MATERIALS AND METHODS: This study followed a prospective, randomized, and balanced, double-blinded (assessor) protocol. Twenty DRG-S responders were randomized to a sequence of three programs for consecutive two-week intervals: continuous stimulation; 1 minute on:1 minute off; or 1 minute on:2 minutes off. The primary outcome of this study was change in pain ratings with the cycled programs compared with continuous stimulation. Secondary outcomes included changes in function and scores for quality of life, and stimulation program preference. RESULTS: Mean scores were similar at the end of each two-week stimulation program for Numerical Rating Scale pain (continuous = 2.9 ± 0.8, 1:1 on-off = 2.6 ± 0.7, and 1:2 on-off = 2.7 ± 0.7 cm, p = 0.39), disability (p = 0.72), and general health (p = 0.95). No clinically significant differences were found from the upper boundaries of the 95% confidence intervals of the mean difference in pain, disability, and general health for each intermittent stimulation program vs the continuous program. At the end of the study, the continuous stimulation, 1:1 on-off dosing, and 1:2 on-off dosing programs were preferred by a similar number of patients. CONCLUSIONS: Intermittent DRG-S produces comparable results to continuous stimulation over a two-week period. Intermittent delivery may extend battery life and facilitate a smaller implantable pulse generator.

Teleprogramming Service Provides Safe and Remote Stimulation Options for Patients with DRG-S and SCS Implants.

BACKGROUND: Chronic pain patients implanted with a neurostimulation device typically require follow-up and device programming visits to address changes in symptoms or treatment. Follow-up visits require access to specialty care and necessitate patients to take time off work, commute long distances, arrange for travel, and/or work with a caregiver's schedule. Telemedicine was adopted for some patient management as a result of the Sars-Cov-2 pandemic; however, remote optimization for neuromodulation still required an in-person visit to adjust device parameters. An FDA-approved digital platform enables remote programming of an implanted neuromodulation device using a real-time audio-video link from the clinical programmer to the patient controller. The Remote Optimization, Adjustment, and Measurement for Chronic Pain Therapy (ROAM-CPT) is a multi-center, prospective study that is currently underway to access the effectiveness of the teleprogramming system in fulfilling patients' clinical demands. METHODS: This pilot study surveyed 16 patients to determine the ability of the teleprogramming platform to provide a rapid solution safely and effectively for patient's chronic pain. Data were collected using a questionnaire that asked 6 clinician-centric questions and 5 patient-centric questions. RESULTS: 4/4 surveyed physicians were able to address patients' needs. 16/16 surveyed patients reported a quick resolution to pain and 15/16 did not require additional follow-up. Data curated from this pilot study show that the teleprogramming application greatly improves patient care, is preferred by both clinicians and patients with minimal disruptions to patients' everyday lives. CONCLUSION: Teleprogramming provides real-time virtual programming capabilities and optimizes patients' therapy. PERSPECTIVE: This article describes remote device programming and analysis as an alternative to in-person programming/treatment sessions for neuromodulation patients. This remote option gives patients access to timely and clinically appropriate device management when in-person care may not be available.

A paramedian approach for dorsal root ganglion stimulation placement developed to limit lead migration and fracture.

INTRODUCTION: Dorsal root ganglion stimulation (DRG-S), has demonstrated superiority in the treatment of complex regional pain syndrome and causalgia. Lead migration and fracture impact DRG-S therapeutic stability. Lead anchoring reduces DRG-S lead migration without increasing lead fracture. Lead fracture may be related to lead entrapment in the superficial fascial plane. A novel medialized approach for lead placement and anchoring is presented to address these issues. METHODS: We suggest an alternative technique for implanting percutaneous DRG-S leads at the T10-L5 levels. RESULTS: A novel medialized ipsilateral technique for lead placement and anchoring for single, bilateral, and adjacent segment placement is presented. The Tuohy needle puncture site is medial to the pedicle and adjacent to the spinous process, two vertebral levels caudad to the target foramen. Trajectory is maintained in the sagittal plane, to access the caudad interlaminar space near the midline. This technique allows for ipsilateral or contralateral lead placement. After epidural access, the introducer sheath is rotated toward the targeted foramen and advanced. The guidewire followed by the lead is passed, and once lead position is confirmed, tension "S" loops are created, followed by anchoring to the deep fascia. CONCLUSION: We describe a new paramedian technique for DRG-S lead placement. We propose it will decrease DRG-S complication rates through anchoring to reduce migration and by avoiding the fascial planes thought to be responsible for fracture. Long-term outcomes applying our proposed techniques are required for determining the true impact, however, early anecdotal results suggest that these new techniques are favorable.

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.