Dorsal Root Ganglion Stimulation for Chronic Postoperative Pain Following Thoracic Surgery: A Pilot Study.

Objectives: Post-thoracotomy pain syndrome (PTPS) is defined as persistent pain following a thoracotomy and has an incidence of 21-61%. Dorsal root ganglion stimulation (DRG-S) is a form of neuromodulation that modulates pain signal transmission to the spinal cord. The aims of this study were to investigate the efficacy of DRG-S for the management of PTPS and to assess the role of thoracic paravertebral blocks (t-PVB) as a tool for prediction of success of DRG-S.

Materials And Methods: In this prospective study, we included all patients undergoing thoracic surgery, with PTPS not responding to pharmacotherapy and treated with DRG-S from September 2018 to February 2019. t-PVB followed by a percutaneous DRG-S trial was performed on all patients. Pain intensity was assessed through a numeric rating scale (NRS) and Douleur Neuropathique en 4 Questions (DN4) at baseline, post-trial, at 14 days, 90 days, and at one year after DRG-S implantation. Data summarized as continuous variables were expressed as means and standard deviations (SDs), and categorical variables were expressed as raw numbers and percentages.

Results: Four patients out of 51 who underwent thoracic surgery at our institution surveyed were included (mean age ± SD, 56 ± 16 years old). Mean NRS and DN4 were, respectively, 7.2 ± 0.96 SD and 8.2 ± 0.5 SD at baseline, 2.5 ± 0.6 SD and 3.2 ± 0.5 SD after t-PVB, 2.2 ± 0.5 SD and 2.2 ± 0.5 SD at 14 days, 90 days, and at one year after DRG-S implantation. No complications or side effects were reported.

Conclusions: Our preliminary results show that DRG-S is an effective therapy for PTPS after thoracic surgery. In addition, thoracic paravertebral blocks performed prior to DRG-S correlated with a positive outcome with treatment.