Respiratory function after phrenic nerve transfer by end-to-side neurorrhaphy

Abstract

Objective To investigate changes in respiratory function of patients with brachial plexus avulsion injuries (BPAIs) after phrenic nerve transfer by end-to-side neurorrhaphy.Methods A series of 5 patients with BPAI underwent phrenic nerve transfer to anterior division of the upper trunk or to the musculocutaneous nerve by end-to-side neurorrhaphy to reconstruct elbow flexion.Pre-and post-operative pulmonary function tests,chest fluoroscopy and phrenic nerve conduction studies were performed to evaluate the respiratory function and function of diaphragm on the affected side.Results The forced vital capacity(FVC),forced expiratory volume in one second (FEV1) and total lung capacity (TLC) measured 35 months postoperatively were not significantly different from the preoperative pulmonary function measurements in all the patients.Chest X-ray and fluoroscopy showed neither elevation nor reduced movement of diaphragm on the operated side.Phrenic nerve conduction study revealed an average of 2.9 ms increase in latency and 32.4％ decrease in action potential amplitude when compared to preoperative values.In addition reinnervation of the biceps was successful in all the patients.Biceps muscle strength reached M3 or higher in 3 patients.Conclusion Phrenic nerve transfer by end-to-side neurorrhaphy can lead to functional biceps recovery without compromising pulmonary function.It can be an alternative procedure for patients whose diaphragm function needs to be preserved. Key words: Phrenic nerve; Nerve transfer; Respiratory function