Phrenic Nerve Reconstruction with Short-Term Diaphragm Pacing Corrects Diaphragm Paralysis Due to Intrathoracic Nerve Injury.

Abstract

Background: Symptomatic diaphragm paralysis and subsequent pulmonary debilitation has been shown to occur following phrenic nerve injury within the thoracic cavity. In this study, the authors investigated the effectiveness of intrathoracic reconstruction of the phrenic nerve combined with short-term diaphragm pacing in restoring diaphragm function.

Methods: A retrospective review of 34 consecutive patients who underwent intrathoracic phrenic nerve reconstruction and diaphragm pacing for symptomatic diaphragm paralysis was performed. Inclusion criteria included confirmation of diaphragm paralysis on chest fluoroscopy, body mass index less than 40, age younger than 75 years, and presence of functional motor units on electromyographic testing. Surgical treatment consisted of intrathoracic phrenic nerve reconstruction with simultaneous implantation of a diaphragm pacemaker.

Results: A total of 34 patients met inclusion criteria, including 23 men and 11 women, with an average age of 46 years and average body mass index of 28.5 kg/m 2 . Thirty patients (88%) reported improvement in respiratory function. Forced vital capacity and forced expiratory volume in 1 second values improved by 15% ( P = 0.02) and 14% ( P = 0.049), respectively. A 375% increase in diaphragm motor amplitude was observed, from 0.04 mV to 0.19 mV ( P = 0.02). Radiographic improvement in resting diaphragm position and contraction was demonstrated in 71% of patients. Complications included pacemaker site infection (5%), cardiac arrythmia (5%), and asymptomatic abdominal bulge (3%).

Conclusions: Intrathoracic phrenic nerve reconstruction with short-term diaphragm pacing is a safe and effective surgical treatment that improves diaphragm function and alleviates symptoms of respiratory insufficiency in patients with diaphragmatic paralysis following intrathoracic phrenic nerve injury. This approach should be considered as part of the treatment algorithm for this patient population.

Clinical question/level of evidence: Therapeutic, IV.