Regenerative Peripheral Nerve Interface (RPNI) for the Management of Postamputation Pain in Oncology Patients.

Background: Challenges in chronic pain management among post-amputation oncology patients have led to a shift in treatment paradigms. Regenerative Peripheral Nerve Interface (RPNI) has shown promise in attenuating neuropathic pain following traumatic major limb amputations. This study evaluates the utility of prophylactic RPNI among oncology patients requiring major upper and lower extremity amputation. The primary outcome is to evaluate the effectiveness of prophylactic RPNI in preventing symptomatic neuromas among oncology patients.

Methods: A retrospective review was conducted for patients with bone and soft tissue tumors who underwent major limb amputation at a single academic institution between 2010-2023. Patients who underwent prophylactic RPNI (N=27) were compared with a control group (N=35). Outcomes included preoperative pain, postoperative neuroma formation, phantom limb pain (PLP), and chronic opioid use. Statistical analysis was performed using the Chi-Squared test with GraphPad Prism 10.

Results: Twenty-seven oncology patients (70.4% male, mean age 49.8 years) underwent amputation with prophylactic RPNI. The mean follow-up was 26.3 months (range: 3-58.5 months). The RPNI group included 9 upper and 18 lower extremity amputations. There were no symptomatic neuromas among the RPNI patients. In contrast, symptomatic neuromas were identified among 28.6% of the controls. At 12 months postoperatively, 91.3% of RPNI patients reported "no" or "mild" PLP compared to 70.8% of controls. Additionally, 90% of RPNI patients discontinued opioids within 6 months, compared to 50% of controls.

Conclusion: Prophylactic RPNI at the time of major limb amputation for oncology patients is associated with a substantial reduction in pain and opioid use.