Effectiveness and Safety of Dorsal Root Ganglion Stimulation for the Treatment of Chronic Pain: A Pooled Analysis

Abstract

Introduction Since it became available in the mid‐2010s, dorsal root ganglion (DRG) stimulation has become part of the armamentarium to treat chronic pain. To date, one randomized controlled trial, and several studies of moderate sample size and various etiologies have been published on this topic. We conducted a pooled analysis to investigate the generalizability of individual studies and to identify differences in outcome between chronic pain etiologic subgroups and/or pain location. Materials and Methods One prospective, randomized comparative trial and six prospective, single‐arm, observational studies were identified that met pre‐defined acceptance criteria. Pain scores and patient‐reported outcome (PRO) measures were weighted by study sample sizes and pooled. Safety data are reported in aggregate form. Results Our analysis included 217 patients with a permanent implant at 12‐month follow‐up. Analysis of pooled data showed an overall weighted mean pain score of 3.4, with 63% of patients reporting ≥50% pain relief. Effectiveness sub‐analyses in CRPS‐I, causalgia, and back pain resulted in a mean reduction in pain intensity of 4.9, 4.6, and 3.9 points, respectively. Our pooled analysis showed a pain score for primary affected region ranging from 1.7 (groin) to 3.0 (buttocks) and responder rates of 80% for foot and groin, 75% for leg, and 70% for back. A substantial improvement in all PROs was observed at 12 months. The most commonly reported procedural or device complications were pain at the IPG pocket site, lead fracture, lead migration, and infection. Conclusions DRG stimulation is an effective and safe therapy for various etiologies of chronic pain.

Three-Year Outcomes After Dorsal Root Ganglion Stimulation in the Treatment of Neuropathic Pain After Peripheral Nerve Injury of Upper and Lower Extremities

“…The number of complications observed in our retrospective analysis is consistent with the data of the pool analysis by Huygen et al These authors identified pain at the IPG pocket site (10.2%), lead fractures and migrations (11.8%), infections (5.1%) (26) as the most frequent complications. This rate may appear relatively high; but, it must be taken into account that this was still a young and technically completely new therapeutic procedure (41).…”

“…However, long‐term evidence of effectiveness is lacking. Also, the study of Huygen et al (26) was set up to present pooled data up to one‐year post‐permanent implant as this is the most common follow‐up period in published literature. There is an urgent need to collect and analyze long‐term data.…”

Case Study: Neuropathic Itching Following S3 and S4 Dorsal Root Ganglion Stimulator Trial

“…A pooled analysis by Huygen and colleagues found the most frequently reported complications of DRG stimulation were infections (5.1%), lead fractures (5.9%), lead migration (5.9%), temporary motor stimulation (4.7%), dural puncture (4.3%) and pain at IPG pocket site (10.2%). 6 There was no mention of itch or pruritus as a reported complication. A recent retrospective analysis by Kretzschmar and colleagues determined that their complications were consistent with those that Huygen et al had reported.…”

Response to Letter to the Editor Regarding “Complications and Effects of Dorsal Root Ganglion Stimulation in the Treatment of Chronic Neuropathic Pain: A Nationwide Cohort Study in Denmark”

“…This highlights the importance of a comprehensive follow-up in detecting complications. It is worth noting that a pooled analysis of 217 patients from seven studies found the therapy to be effective and safe (4). And yet, in the public peer-review comments, the point is made that "rare complications are unlikely to show up in early prospective studies.…”