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, we investigate 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, BMI <40, Age <75, and presence of functional motor units on EMG testing. Surgical treatment consisted of intrathoracic phrenic nerve reconstruction with simultaneous implantation of a diaphragm pacemaker.

Results: 34 patients met inclusion criteria, including: 23 males and 11 females with an average age of 46 and average BMI of 28.5 kg/m2. Thirty patients (88%) reported improvement in respiratory function. FVC and FEV1 values improved by 15% (p=0.02) and 14% (p=0.049), respectively. A 375% increase in diaphragm motor amplitude was observed, from 0.04mV to 0.19mV (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.