Contralateral C7 transfer to lower trunk via the prespinal route in the repair of brachial plexus injury: an experimental study in rats.

Contralateral C7 (cC7) root transfer to reconstruct brachial plexus injury (BPI) has been widely used. A revised technique that cC7 root was transferred to lower trunk via the prespinal route with direct neurorrhaphy has been reported clinically. The aim of this experimental study was to develop an animal model of the modified surgical approach in order to obtain quantification index of postoperative nerve regeneration and muscle morphology. Sixty adult Sprague-Dawley rats randomized into experimental and control groups of 30 each. In the experimental group, after total brachial plexus injury (BPI) the cC7 root was transferred to lower trunk via the prespinal route with direct neurorrhaphy, and in the control group the brachial plexus was only exposed without intervention. Electrophysiological study, muscle tension test, neuromorphology, muscle wet weight, and muscle fiber cross-sectional area measurements were obtained 4, 8, and 12 weeks postoperatively. Median and ulnar nerve regeneration and the forearm flexor muscles functional recovery were obtained by cC7 root transfer to lower trunk via the prespinal route when measured at 12 weeks following the operation though the parameters had not recovered to normal value. We concealed the control and experimental groups from those who did the evaluations.