Effectiveness and Safety of Platelet-Rich Plasma Combined with Pulsed Radiofrequency to Treat Patients with Infraorbital Neuralgia: A Propensity Score-Matched Analysis of a Multi-Center, Prospective Cohort Protocol.

Background: Infraorbital neuralgia (IONa) is a rare but devastating type of facial pain, with a lack of current consensus on its proper management. Preliminary studies have established the efficacy of pulsed radiofrequency (PRF) in the treatment of IONa. Platelet-rich plasma (PRP) is a non-destructive technique that alleviates neuropathic pain. Till date, the efficacy of PRP combined with PRF in the treatment of IONa has not been evaluated yet.

Objective: To evaluate the efficacy and safety of PRP combined with PRF in treating refractory IONa in patients unwilling to undergo destructive therapies.

Study design: A multicenter, prospective, observational, propensity score matching (PSM), and assessor-blinded study.

Setting: Department of pain management in Beijing, Wuhan and Qingdao, China.

Methods: A total of 240 refractory IONa patients will be allocated to either PRP combined with PRF therapy (PRP+PRF) group or PRF therapy alone (PRF) group at their own volition. Statistical analysis will be performed using Pearson's chi-squared or Fisher's exact test for categorical variables, Student's t-test and Mann-Whitney U-test for continuous variables. Logistic regression will be used to evaluate the pain - relief efficacy.

Results: The primary outcome will be the 12-months response rate. The secondary outcome will include NRS score, total daily dose of carbamazepine, the 12-item Short-Form Health Survey (SF-12) scores, patient satisfaction scores (PSS) and adverse events (AEs).

Limitation: This is an observational, open-labeled study with a relatively short term follow-up. The composition of PRP and various cell ratios, which are optimal for IONa has not been published yet.

Conclusion: This will be a multi-center trial with a relatively large sample size, demonstrating the potential benefits of PRP combined with PRF therapy in IONa patients. Further, randomized controlled trial (RCT) will be necessary to confirm the efficacy of this combined therapy.