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.