Histopathological nerve assessment in brachial plexus birth injuries

In children suffering from brachial plexus birth injuries (BPBI), one major difficulty concerns intraoperative selection of the roots to be used for reconstruction. Between November 2018 and August 2020, surgical qualitative evaluations and pathological quantitative analyses were conducted on 52 roots and 29 distal neural stumps (trunks, divisions, cords, and nerves distal to the neuroma) in 17 patients who underwent brachial plexus reconstruction. For each root, surgeons rated stump quality as "good", "fair" or "avulsed". Neural sections were then sent to pathology to determine percentage intraneural fibrosis under microscopy. Mean root intraneural fibrosis rates were 30.5% (SD 24.9; range, 0-80%), 46.3% (SD 32.6; range, 0-90%) and 24.6% (SD 23.5; range, 0-80%) in the "good quality", "fair quality" and "avulsed" groups, respectively, with no significant differences between groups. In distal neural stumps, the mean intraneural fibrosis rate was 30.9% (SD 24.7). These findings raise the question of conducting frozen section biopsy of neural stumps after neuroma resection to determine surgical reconstruction strategy.