Postoperative diaphragmatic paralysis after cardiac surgery in children: incidence, diagnosis and surgical management

Background Cardiac surgery for congenital heart disease covers a wide spectrum from simple to complex cardiac and extracardiac malformations. Innovations in pediatric cardiac surgery and perioperative care over the past decades have allowed surgical correction or at least palliation in almost all complex congenital heart defects in the first years of life. Diaphragmatic paralysis (DP) due to phrenic nerve injury after congenital cardiac surgery is an important respiratory complication resulting with respiratory insufficiency, lung infections, prolonged hospital stay time and even death. Methods Between April 2001 and December 2010, among patients undergoing cardiac surgery for congenital heart disease, postoperative DP was diagnosed in 47/10 200 (0.46%) patients. Diaphragmatic placation was performed in 37/47 patients. DP was suspected in children who failed to wean from mechanical ventilation or in those with persistent respiratory distress when there is no cardiac cause. Decreased respiratory sounds in auscultation, paradoxical breathing during spontaneous ventilation and elevated hemidiaphragm on chest X‐ray led us to use fluoroscopy, ultrasound and/ or electromyogram (EMG). When chest X‐rays did not have a diagnostic value in patients with persistent respiratory distress, bilateral DP was suspected and immediate fluoroscopy of EMG was performed for diagnosis. In all patients, diaphragmatic placation was performed using a thoracic approach, through the sixth or seventh intercostals space with lateral thoracotomy. Results A total of 47 patients (21 females and 26 males) with a median age of 7.21 months (range 0.27‐71 months) were diagnosed DP after cardiac surgery. The incidence of DP was 0.46% after cardiac surgery. The paralysed hemidiaphragm was left side in 26/47 (55.3%), right side in 17/47 (36.2%) and bilateral in 4/47 (8.5%) cases. The assisted ventilation time after cardiac surgery was (450±216) (116‐856) hours. The median time from cardiac surgery to surgical placation was (24±14) (5‐56) days. No patient died in this study. The follow‐up period was (26.2±16.8) months. The position of the plicated diaphragm was normal on chest X‐ray, in all plicated survivors within the 1st, 6th and 12th months after discharge. Conclusions DP caused by phrenic nerve injury during surgical intervention for congenital heart disease is an important risk factor in terms of morbidity during the postoperative period. Diaphragmatic placation appears a good option, especially in newborns and small children, to wean patients from mechanical ventilation and to prevent long‐term side effects of mechanical ventilation.