Diaphragm dysfunction following surgery for congenital heart disease is a known complication leading to delays in recovery and increased post-operative morbidity and mortality. We aimed to determine the incidence of and risk factors associated with diaphragm plication in children undergoing cardiac surgery and evaluate timing to repair and effects on hospital cost and length of stay.

We conducted a multi-institutional retrospective observational cohort study. Forty-three hospitals from the Pediatric Health Information System database were included, and a total of 112,110 patients admitted between January 2004 and December 2014 were analysed.

Patients less than 18 years of age who underwent cardiac surgery were included. Risk Adjustment for Congenital Heart Surgery was utilized to determine procedure complexity. The overall incidence of diaphragm dysfunction was 2.2% (n = 2513 out of 112,110). Of these, 24.0% (603 patients) underwent diaphragm plication. Higher complexity cardiac surgery (Risk Adjustment for Congenital Heart Surgery 5–6) and age less than 4 weeks were associated with a higher likelihood of diaphragm plication (p-value < 0.01). Diaphragmatic plication was associated with increased hospital length of stay (p-value < 0.01) and increased medical cost.

Diaphragm plication after surgery for congenital heart disease is associated with longer hospital length of stay and increased cost. There is a strong correlation of prolonged time to plication with increased length of stay and medical cost. The likelihood of plication increases with younger age and higher procedure complexity. Methods to improve early recognition and treatment of diaphragm dysfunction should be developed.