Longitudinal Analysis of Ventilation Perfusion Mismatch in Congenital Diaphragmatic Hernia Survivors.

OBJECTIVE: To determine the natural history of pulmonary function for survivors of congenital diaphragmatic hernia (CDH). STUDY DESIGN: This was a retrospective cohort study of survivors of CDH born during 1991-2016 and followed at our institution. A generalized linear model was fitted to assess the longitudinal trends of ventilation (V), perfusion (Q), and V/Q mismatch. The association between V/Q ratio and body mass index percentile as well as functional status was also assessed with a generalized linear model. RESULTS: During the study period, 212 patients had at least one V/Q study. The average ipsilateral V/Q of the cohort increased over time (P < .01), an effect driven by progressive reduction in relative perfusion (P = .012). A higher V/Q ratio was correlated with lower body mass index percentile (P < .001) and higher probability of poor functional status (New York Heart Association class III or IV) (P = .045). CONCLUSIONS: In this cohort of survivors of CDH with more severe disease characteristics, V/Q mismatch worsens over time, primarily because of progressive perfusion deficit of the ipsilateral side. V/Q scans may be useful in identifying patients with CDH who are at risk for poor growth and functional status.

Longitudinal Analysis of Pulmonary Function in Survivors of Congenital Diaphragmatic Hernia.

OBJECTIVE: To analyze longitudinal trends of pulmonary function testing in patients with congenital diaphragmatic hernia (CDH) followed in our multidisciplinary clinic. STUDY DESIGN: This was a retrospective cohort study of CDH patients born between 1991 and 2013. A linear mixed effects model was fitted to estimate the trends of percent predicted forced expiratory volume in 1 second (FEV1pp), percent predicted forced vital capacity (FVCpp), and FEV1/FVC over time. RESULTS: Of 268 patients with CDH who survived to discharge, 119 had at least 1 pulmonary function test study. The FEV1pp (P < .001), FVCpp (P = .017), and FEV1/FVC (P = .001) decreased with age. Compared with defect size A/B, those with defect size C/D had lower FEV1pp by an average of 11.5% (95% CI, 2.9%-20.1%; P = .010). A history of oxygen use at initial hospital discharge also correlated with decreased FEV1pp by an average of 8.0% (95% CI, 1.2%-15.0%; P = .023). CONCLUSIONS: In a select cohort of CDH survivors, average pulmonary function declines with age relative to expected population normative values. Those with severe CDH represent a population at risk for worsening pulmonary function test measurements who may benefit from recognition and monitoring for complications.