Integrating dorsal root ganglion stimulation with transforaminal lumbar interbody fusion: proof of concept study.

BACKGROUND: Transforaminal lumbar interbody fusion (TLIF) is a modality for treatment of chronic lower back pain (CLBP) and/or lumbosacral radiculopathy (LR). Up to 28% of patients with indications for surgical treatment of CLBP/LR continue to have CLBP/LR after surgery despite a technically successful spinal surgery, likely due to development or persistence of neuropathic pain. Dorsal root ganglion (DRG) stimulation is often used for the treatment of chronic neuropathic pain. Thus, we present a novel technique of integrating DRG stimulation using Direct Visual Placement with open lumbar or lumbosacral decompression and instrumented fusion in a single surgical procedure.

METHODS: In an uncontrolled case series for a proof of concept study, we combined DRG stimulation with TLIF in a single surgical procedure to evaluate feasibility and safety. Fifteen patients with CLBP/LR and indication for TLIF received DRG stimulator placement concomitantly during TLIF. Safety of the combined approach, namely adverse event (AE), was evaluated. Also, change in back pain and leg pain visual analog scale (VAS) scores, as well as opioid usage, from baseline to 12 weeks, 6 months, and 12 months postoperatively, was tracked.

RESULTS: No AE was serious, and was related to the 2 procedures, TLIF and DRG stimulation, being combined. One instance of electrode migration without loss of therapy was recorded. Stimulation parameters were 20 Hz frequency, 250 microsecond pulse width, and less than 1 mA amplitude. Back pain VAS scores improved 67%, 72%, and 71% from baseline at 12 weeks, 6 months, and 12 months, respectively. Leg pain VAS scores improved 67%, 69%, and 69% from baseline at 12 weeks, 6 months, and 12 months, respectively. Responder (VAS score reduction of at least 50%) analysis of back pain and leg pain VAS scores showed that 53.3% and 60.0% of subjects responded to stimulation at 10-20 days for back pain and leg pain, respectively. Responder rates increased to 66.7% and 73.3% at 12 months for back pain and leg pain, respectively. Responder rates for "either" or "both" were 80.0% and 66.0% at 12 months, respectively. Opioid usage was down to 20% from 12 weeks to 12 months.

CONCLUSIONS: This series demonstrates the feasibility of integrating DRG stimulator placement with open lumbar or lumbosacral decompression and instrumented fusion. The Direct Visual Placement of DRG stimulator demonstrated no TLIF and DRG stimulation combination related AEs, showed feasibility, reduced pain and improved quality of life of the subjects, thus presenting a new treatment approach for CLBP/LR in a single procedure.