Continuous electrical stimulation of the dorsal root ganglion (drg-s) as a salvation therapy in patients previously treated with spinal cord stimulation. systematic review and pooled analysis.

Abstract

Background context: Treatment techniques on the dorsal root ganglion has offered a broad overview in the chronic pain. The aim is to review the existing evidence on DRG-s as a "salvation" of spinal cord stimulation therapies. We make a grouped analysis of the patients treated.

Methods: A systematic search of the medical literature was conducted based on the principles recommended by PRISMA. In the phase 1 (DRG-S therapy as a "salvation" treatment for patients with SCS) the following search words were used: "ganglia", "DRG", "dorsal root ganglion", "neurostimulation", "salvage", "salvation", "habituation", "spinal cord stimulation". In the phase 2 studies using DRG-S therapy with previous SCS were included. The following words were used as search words in the databases: "spinal ganglia", "DRG", "dorsal root ganglion", "neurostimulation". The search included articles from each databases creation through August 2025.

Inclusion: Systematic review, randomized clinical trials, observational studies, case series. Cadaveric and experimental articles were excluded.

Results: In the phase 1, 230 articles were identified and 10 of them were selected for analysis. In the phase 2, 530 articles were identified and 45 of them were selected for analysis. The Prisma checklist for systematic reviews was applied and the risk of bias and the quality of the study were evaluated based on the STROBE and CONSORT criteria. 147 patients were identified has having previously had a SCS, who had previously undergone a SCS trial phase or who had an implanted and active system at the time of the study. In 31/147 patients, detailed information on clinical or therapeutic aspects related to the SCS was not included in the articles. The cause of chronic pain was most frequently reported as CRPS (37%) and PSPS (36%). It included other pathologies such as: chronic pelvic pain, radiculopathy, peripheral neuropathic pain, gonalgia, post-thoracotomy pain, post-inguinal herniorrhaphy pain, phantom limb pain and severe peripheral artery disease. The follow-up period and the analysis of the results were very varied, but it can be concluded that in most cases the use of DRG-s was indicated due to a poor clinical response to SCS despite not specifying what type of stimulation was being performed (in most cases SCS-t) or whether the therapy was salvaged with other forms of SCS (Burst, high frequency, ECAP- controlled closed-loop, Differential Target Multiplexed,etc.). In most patients implanted with DRG-s the clinical result was better and the degree of patient satisfaction with the new therapy was clear.

Conclusions: DRG-s is a useful procedure in the treatment of chronic pain. It emerges as a complementary tool that can be used even in patients who have (or have had) an SCS. It should be included together with new forms of spinal cord stimulation in the therapeutic arsenal of patients with refractory chronic pain. There will be situations where DRG-s will help improve patients with loss of SCS efficacy, just as the opposite may also occur. A detailed clinical analysis will always be necessary to ensure the benefit of the patient and the sustainability of healthcare systems.