Histopathological Confirmation of Axonal Sprouting in Regenerative Peripheral Nerve Interface

Area of Science:

• Regenerative Peripheral Nerve Interface (RPNI) surgery
• Histopathology
• Peripheral nerve regeneration

Background:

• Symptomatic neuromas are a common complication following major limb amputation.
• Regenerative Peripheral Nerve Interface (RPNI) surgery is a promising intervention to prevent neuroma formation.
• Previous studies in animals showed RPNI promotes axonal sprouting and synaptogenesis, but human data is lacking.

Observation:

• This case report details a patient who underwent below-knee amputation with RPNI for foot gangrene due to polyarteritis nodosa.
• A subsequent above-knee amputation allowed for histopathological examination of the RPNI site.
• The examination focused on the tibial nerve stump within the grafted muscle.

Findings:

• Histopathological analysis confirmed axonal sprouting and elongation of the tibial nerve within the RPNI muscle graft.
• The presence of neuromuscular junctions was identified, suggesting functional integration.
• This is the first human study to demonstrate these physiological nerve regeneration processes at the RPNI site.

Implications:

• These findings support the efficacy of RPNI in promoting nerve regeneration and potentially mitigating neuroma pain in human patients.
• This histopathological evidence provides a foundation for further clinical research and application of RPNI.
• RPNI may represent a significant advancement in surgical techniques for amputees, improving quality of life.