Peripheral nerve regeneration inside collagen-based artificial nerve guides in humans

Area of Science:

• Regenerative Medicine
• Neuroscience
• Biomaterials Science

Background:

• Nerve gap injuries often accompany damage to surrounding tissues like tendons and bones.
• Functional recovery frequently necessitates secondary surgical interventions.
• Macroscopic human nerve regeneration data is scarce, limiting understanding of healing processes.

Purpose of the Study:

• To investigate human nerve regeneration in vivo using collagen-based nerve guides.
• To leverage secondary surgeries as an opportunity for direct observation of nerve repair.
• To assess clinical outcomes and macroscopic regeneration within nerve guides.

Main Methods:

• Clinical outcomes of 50 upper limb collagen-based nerve guide implants were evaluated.
• Twenty patients underwent a second-look surgery for macroscopic assessment.
• Nerve regeneration and collagen degradation were directly observed and analyzed.

Main Results:

• No instances of pain were reported by patients.
• Sensory recovery was observed in cases with confirmed nerve regeneration within the guide.
• Effective motor recovery was associated with nerve gap lesions less than 10 mm.
• Collagen degradation varied and was not time-dependent, possibly influenced by implantation site.

Conclusions:

• Collagen-based nerve guides facilitate sensory recovery in human nerve gap injuries.
• Motor recovery is achievable for shorter nerve gaps (<10 mm).
• The study provides unprecedented macroscopic human data on nerve regeneration and guide degradation.