Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation: Neuromodulation of the Femoral Nerve for Postoperative Analgesia following ACL Reconstruction
Ilfeld BM, Sztain JF, Said ET, Abramson WB, Khatibi B, Gabriel RA, Finneran JJ, Jaeger PT, Covey DC, Robertson C
University California San Diego
•Percutaneous peripheral nerve stimulation (pPNS) or “neuromodulation” is an analgesic modality involving the insertion of an electrical lead through an introducing needle—obviating the requirement of a surgical incision for placement—followed by the introduction of electric current
•Neuromodulation is based on “gate control theory”, in which electric current stimulates large-diameter afferent nerve fibers that subsequently interrupt communication (the “gate”) from small-diameter pain fibers to the central nervous system at the level of the spinal cord.
•This therapy has multiple theoretical benefits over existing analgesic modalities: a lack of systemic side effects (e.g., opioid-induced nausea, respiratory depression), diversion and abuse potential, local anesthetic-induced sensory, motor, and proprioception deficits, and significant foreign body infection risk
•The US FDA has cleared an available lead and stimulator for the treatment of acute pain for use up to 60 days
•Percutaneous PNS has been used to treat chronic pain and post-operative pain following knee arthroplasty
•The purpose of this feasibility study was to explore the possibility of providing analgesia following painful ambulatory ACL reconstruction.
•The protocol was prospectively registered (NCT02898103), approved by the local IRB, and all subjects provided written informed consent. Lead insertion occurred within 2 weeks prior to ACL reconstruction with a patellar autograph..
•A helically-coiled, insulated electrical lead was percutaneously inserted 1-2 cm superficial to the femoral nerve just inferior to the inguinal crease using a short-axis, in-plane ultrasound-guided approach..
•A general anesthetic was administered during surgery and a pulse generator (“stimulator”) was connected to the lead and initiated in the recovery room (SPRINT, SPR Therapeutics, Cleveland, Ohio).
•Rescue analgesia was provided with opioids and—if needed—a ropivacaine 0.2% perineural infusion via an adductor canal catheter during the first three days. Subjects were discharged home and followed daily by telephone.
•Subjects returned to the clinic for lead removal with simple traction by an investigator between POD 14-28.
•Subjects (n=5) reported relatively low pain scores and opioid requirements in the first 2 postoperative weeks, although 80% did use perineural infusion during the first 2-3 POD.
•No subject reported sensory deficits to cold or light touch, or motor deficits at any time during stimulation.
•One subject experienced discomfort near the lead tip with stimulation and discontinued use POD 3 with lead removal on POD 7. No other lead-related adverse events were reported.
•Another subject had his lead removed POD 6 due to having to unexpectedly leave the state
•This proof-of-concept study demonstrates that pPNS is feasible for ambulatory knee surgery; and suggests that this modality both provides analgesia and decreases reliance on opioids following ACLR with a patellar autograph.