Intraoperative Assessment of Nerve Traction Injury in Obstetric Brachial Plexus Palsy

Abstract

We present an easy classification for nerve lesions observed in reconstructive surgery for obstetric brachial plexus palsy, performed through a supraclavicular approach and systematic exposure of nerve roots and trunks. A description of signs related to nerve traction injury (scarring, fascicular rupture, and dislocated ganglions) is combined with a grading system of microscopic tissue changes occurring in slices from traumatized nerve endings (fascicular structure, changes in perineurium and endoneurium). Both tools are proposed for any surgical brachial plexus exploration and later interaction with other professionals (pediatricians, physiotherapists, or obstetricians).

Keywords: brachial plexus; endoneurium; fibrosis; minifascicles; nerve regeneration; nerve traction; obstetric palsy; perineurium.

Fig. 1

Translation of external lateral traction forces between head and shoulder onto the nerve structures of the brachial plexus: ( 1 ) The most lateral structures are first involved, giving rise to superficial scarring and involvement of the upper trunk and especially the origin of the suprascapular nerve. ( 2 ) A more severe force affects the upper and eventually middle trunk, responsible for Erb́s or extended Erb́s palsy. ( 3 ) Major traumatization spreads to the whole brachial plexus, with the most severe damage (including root avulsions) of the lower trunk (in deep blue, bold).

Fig. 2

Neuropathological tissue changes affecting fascicular structure, endo-, and perineurium.