Phrenic nerve paralysis after pediatric cardiac surgery. Retrospective study of 125 cases.

Phrenic nerve paralysis was diagnosed in 125 children (1.6%) from a series of 7,670 cardiac surgical procedures in infants and children during a 12 year period. The incidence was 1.9% for open heart and 1.3% for closed heart operations. In order of decreasing incidence, the open heart procedures included Mustard procedure (6.7%), right ventricular outflow tract reconstruction (5.6%), and repair of tetralogy of Fallot (2.7%). The closed heart procedures included Glenn anastomosis (6.2%), Blalock-Hanlon atrial septectomy (5.9%), and right Blalock-Taussig shunt (5.1%). Procedures following previous operations or thoracotomies had almost twice the incidence of phrenic nerve paralysis: Mustard procedure 9.9%, right ventricular outflow tract reconstruction 10.8%, and tetralogy repair 5.5%. Seven patients (5.6%) with phrenic nerve paralysis died. Patients less than 2 years old with phrenic nerve paralysis were intubated for 0 to 57 (average 15.7) days after their cardiac operations and those over 2 years old for 13 to 35 (average 7.2) days (p less than 0.001). Twelve patients had diaphragmatic plication without mortality and were extubated 0 to 6 (average 2.3) days after plication. We have made the following conclusions: (1) Phrenic nerve paralysis may occur after both open and closed cardiac procedures and is more common in children requiring reoperation; (2) it is associated with considerable morbidity; (3) eventual recovery of phrenic nerve function occurs in 84% of children; and (4) diaphragmatic plication is safe, reliable, and of most value in patients who are under 2 years of age and require mechanical ventilation for more than 2 weeks.