A novel platelet-rich plasma clinically induces reliable, rapid, long-term chronic peripheral neuropathic pain...

Peripheral nerve trauma results in 50%-84% of patients developing chronic neuropathic pain, which is eliminated when axons reinnervate targets. Autografts reduce pain by promoting target reinnervation. We hypothesized that applying a novel platelet-rich plasma (PRP) formulation to proximal stumps would permanently eliminate the pain. This prospective case series compared analgesia levels after bridging nerve gaps with an autograft (autograft repair) vs. a PRP-filled collagen tube (PRP repair). Autograft repairs were performed on 16 nerves with a 5.75-cm mean gap length, 2.0-year repair delay, 42.3-year age, and 8.6 chronic neuropathic pain. PRP repairs were performed on 10 nerves with a 6.0-cm gap length, 1-year repair delay, 36.7-year age, with 88% having 9.1 chronic neuropathic pain. For autograft repairs, the pain began to decrease when axons reinnervated targets, reaching a mean of 0.3 in 18.2% of patients, and was eliminated in 81.8%. Following PRP repairs, the pain reduction began within 2 weeks and was eliminated by 2 months. Thus, autografts contribute to pain reduction/elimination by promoting target reinnervation. However, PRP directly and rapidly induced long-term pain elimination in all patients, while axons were regenerating, and without target reinnervation. These results prove that platelet-released factors reliably and rapidly eliminate chronic neuropathic pain.