Nerve grafting for peripheral nerve injuries with extended defect sizes

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Neurosurgery

Background:

• Peripheral nerve injuries with extensive tissue loss often require nerve grafts when direct repair is not feasible.
• Current FDA-approved nerve grafts, primarily collagen-based or synthetic, are effective for defects up to 3.0 cm.
• A significant challenge remains in reconstructing longer nerve defects (≥4.0 cm).

Purpose of the Study:

• To review current clinical and experimental strategies for peripheral nerve reconstruction using artificial and non-artificial grafts.
• To explore methods for achieving nerve regeneration in long-distance nerve defects (≥4.0 cm).
• To summarize approaches for enhancing axonal regeneration in peripheral nerve repair.

Main Methods:

• Review of current literature on artificial and non-artificial nerve grafts for peripheral nerve reconstruction.
• Analysis of clinical and experimental studies focusing on short (≤3.0 cm) and long (≥4.0 cm) nerve defects.
• Examination of strategies to promote axonal regeneration, including cellular and molecular adjuncts.

Main Results:

• Marketed nerve grafts, including collagen and poly(DL-lactide-ε-caprolactone) materials, show efficacy in short nerve defects (≤3.0 cm).
• Only one human nerve allograft is FDA-approved for peripheral nerve reconstruction.
• Strategies involving Schwann cells, mesenchymal stem cells, and growth factors show promise for enhancing regeneration in longer defects (4.0–8.0 cm).

Conclusions:

• Nerve reconstruction for extensive peripheral nerve defects remains a significant clinical challenge.
• Current nerve graft technologies are limited in their ability to bridge long nerve gaps (≥4.0 cm).
• Advanced strategies, including cell-based therapies and growth factor supplementation, are essential for improving outcomes in long-distance peripheral nerve repair.