Effect of white adipose tissue flap and insulin-like growth factor-1 on nerve regeneration in rats.

Adipose tissue-derived stem cells and insulin-like growth factor-1 (IGF-1) have shown potential to enhance peripheral nerve regeneration. The purpose of this study was to investigate the effect of an in vivo biologic scaffold, consisting of white adipose tissue flap (WATF) and/or IGF-1 on nerve regeneration in a crush injury model. Forty rats all underwent a sciatic nerve crush injury and then received: a pedicled WATF, a controlled local release of IGF-1, both treatments, or no treatment at the injury site. Outcomes were the normalized maximum isometric tetanic force (ITF) of the tibialis anterior muscle and histomorphometric measurements. At 4 weeks, groups with WATF had a statistically significant improvement in maximum ITF recovery, as compared to those without (P < 0.05), and there was an increase in myelin thickness and total axon count in the WATF-only group versus control (P < 0.01). Functional and histomorphometric data suggest that IGF-1 suppressed the effect of the WATF. Use of a pedicled WATF improved the functional and histomorphometrical results after axonotmesis in a rat model. IGF-1 does not appear to enhance nerve regeneration in this model. Utilizing the WATF may have a beneficial therapeutic role in peripheral nerve injuries.