Brachial plexus neurotization with donor phrenic nerves and its effect on pulmonary function

OBJECT: To examine possible side effects of neurotizations in which the phrenic nerve was used, pulmonary function was analyzed pre- and postoperatively in patients with brachial plexus injury and root avulsions. METHODS: Twenty-three patients with complete brachial plexus palsy underwent neurotization of the musculocutaneous nerve, with the phrenic nerve as donor material. Patients who suffered lung contusions as part of the primary injury were excluded from this study. In 12 patients (five left-sided and seven right-sided neurotizations) pre- and postoperative functional parameters were compared and additional body plethysmography was performed more than 12 months postsurgery. Of the 23, no patient experienced pulmonary problems postoperatively. Nonetheless, pulmonary functional parameters showed a vital capacity in percent of the predicted value of 9.8 +/- 6.3% (mean +/- standard deviation SD]) in all patients examined, which was a significant reduction (p = 0.0002). In right-sided phrenic nerve transfers this reduction was significant, at 14.3 +/- 3.3% (mean +/- SD), whereas left-sided transfers showed a nonsignificant reduction of 3.6 +/- 3.5% (mean +/- SD). The observed decrease in vital capacity (VC) correlates with the maximal inspiratory pressure (Pi(max)) as an indication of clinical significance. CONCLUSIONS: When the right phrenic nerve is used as a donor in neurotization of the musculocutaneous nerve, the patient incurs a higher risk of reduced pulmonary VC. If possible, the left phrenic nerve should be preferred. The Pi(max) has to be determined preoperatively to avoid any further decrease in the already reduced pulmonary function due to the initial injury.