Background: Branch pulmonary artery (PA) stenosis due to ductus arteriosus tissue (DA-PS) contributes to morbidity and mortality associated with pulmonary atresia (PAtr). As preoperative predictors of DA-PS in PAtr remain poorly defined, we sought to identify preoperative echo features that predict DA-PS in PAtr.
Methods: Neonates with PAtr and a ductal-dependent pulmonary circulation surgically managed in our program from 2009-2015 were included. DA-PS was diagnosed as a discrete proximal stenosis of the branch PA ipsilateral to the DA requiring intervention. Preoperative echocardiograms were reviewed to assess 3 features: 1) proximal branch PA diameters, 2) an abnormal relationship between the branch PAs (an inability to image their origins on the same plane), 3) a horizontal course of the ipsilateral PA with a more obtuse posterior angle between the branch PAs. Following review of their clinical course, comparisons were made between those with and without DA-PS.
Results: Seventy-six patients met inclusion criteria. At initial intervention, 51 had an aorto-pulmonary shunt, 23 a biventricular repair and 2 pulmonary valve radiofrequency perforation. DA-PS was found in 41(54%) patients of whom 22 had angioplasty at initial surgery and 34 developed DA-PS postoperatively (including 15 despite surgical angioplasty). On pre-operative echo, patients with DA-PS had a smaller proximal PA ipsilateral to the DA (Z-score -4.0±2.1 vs no DA-PS -1.0±1.9, p<0.0001), a more frequent abnormal branch PA relationship (24(59%) vs 2(6%), p<0.0001) and a more obtuse angle between the PAs (112°±32°vs90°±32°, p=0.007). The ipsilateral PA had a horizontal course in 30(73%) of those with DA-PS versus 3(9%) of those without (p<0.0001). An abnormal PA relationship and/or horizontal course of the ipsilateral PA best predicted DA-PS with a sensitivity, specificity and positive predictive value of 81%, 91% and 92%, respectively.
Conclusions: In patients with PAtr, diagnosis of DA-PS may be improved by identification of pre-operative echo features, including an inability to image the PAs on the same plane and a horizontal course of the PAs. These findings should guide initial surgical management and postoperative surveillance.