Pulmonary Function Outcomes in Children Undergoing Diaphragmatic Plication After Phrenic Nerve Palsy Secondary to Cardiac Surgery: A 10-Year Case Series.

Phrenic nerve injury is a recognised complication of congenital cardiac surgery in children, potentially leading to diaphragmatic paralysis and long-term respiratory dysfunction. Diaphragmatic plication is performed to improve lung mechanics, but its mid-term outcomes remain underexplored. The objective was to assess mid-term pulmonary function in children who underwent diaphragmatic plication for phrenic nerve palsy following congenital heart surgery. This retrospective case series included five children who received left diaphragmatic plication between 2011 and 2021 at a tertiary paediatric centre. Pulmonary function was evaluated using spirometry, plethysmography, and the 6-min walk test (6MWT), and compared to predicted normative values. At a mean follow-up of 5 years, forced volume capacity (FVC), forced expiratory volume (FEV₁), vital capacity (VC), and total lung capacity (TLC) were significantly lower than predicted (p < 0.05). FEV₁/FVC, residual volume (RV), and forced residual capacity (FRC) were not significantly different. All patients completed the 6MWT (> 300 m), though post-exercise oxygen saturation declined significantly (p = 0.011). Diaphragmatic plication leads to a restrictive pattern and exercise-induced desaturation despite preserved walking capacity.