Pulmonary Atresia

ObjectivesIn congenital heart malformations with pulmonary stenosis to atresia an abnormal lateral ductus arteriosus to left pulmonary artery connection can lead to a localised narrowing (pulmonary ductal coarctation) or even interruption We investigated embryonic remodelling and pathogenesis of this area.Material and methodsNormal development was studied in WntCre reporter mice (E10.0-12.5) for neural crest cells and Nkx2.5 immunostaining for second heart field cells. Data were compared to stage matched human embryos and a VEGF120/120 mutant mouse strain developing pulmonary atresia.ResultsNormal mouse and human embryos showed that the mid-pharyngeal endothelial plexus, connected side-ways to the 6th pharyngeal arch artery. The ventral segment formed the proximal pulmonary artery. The dorsal segment (future DA) was solely surrounded by neural crest cells. The ventral segment had a dual outer lining with neural crest and second heart field cells, while the distal pulmonary artery was covered by none of these cells. The asymmetric contribution of second heart field to the future pulmonary trunk on the left side of the aortic sac (so-called pulmonary push) was evident. The ventral segment became incorporated into the pulmonary trunk leading to a separate connection of the left and right pulmonary arteries. The VEGF120/120 embryos showed a stunted pulmonary push and a variety of vascular anomalies.SummarySide-way connection of the DA to the left pulmonary artery is a congenital anomaly. The primary problem is a stunted development of the pulmonary push leading to pulmonary stenosis/atresia and a subsequent lack of proper incorporation of the ventral segment into the aortic sac. Clinically, the aberrant smooth muscle tissue of the ductus arteriosus should be addressed to prohibit development of severe pulmonary ductal coarctation or even interruption of the left pulmonary artery.

BackgroundTo explore the role of contrast-enhanced magnetic resonance angiography (CE-MRA) in clinical routine for evaluating neonates with pulmonary atresia (PA) and to describe their pulmonary artery morphology and blood supply.CE-MRA studies of 15 neonates with PA (12 female; median weight: 2900 g) were retrospectively evaluated by two radiologists in consensus. Each study was judged to be either diagnostic or non-diagnostic depending on the potential to evaluate pulmonary artery morphology and pulmonary blood supply. In those cases where surgery or conventional angiocardiography was performed results were compared.ResultsCE-MRA was considered diagnostic in 87%. Pulmonary artery morphology was classified as "confluent with (n = 1) and without (n = 1) main pulmonary artery", "non-confluent" (n = 6) or "absent" (n = 7). Source of pulmonary blood supply was "a persistent arterial duct" (n = 12), "a direct" (n = 22) or "indirect (n = 9) aortopulmonary collateral artery (APCA)" or "an APCA from the ascending aorta" (n = 2). In no patient were there any additional findings at surgery or conventional angiocardiography which would have changed the therapeutic or surgical approach.ConclusionsCE-MRA is a useful diagnostic tool for the preoperative evaluation of the morphology of pulmonary arteries and blood supply in neonates with PA. In most cases diagnostic cardiac catheterization can be avoided.

ObjectivesTo analyse prenatal parameters predicting biventricular (BV) outcome in pulmonary atresia with intact ventricular septum/critical pulmonary stenosis (PAIVS/CPS).MethodsWe evaluated 82 foetuses from 01/08 to 10/18 in 3 centres in intervals 1 ( 30 weeks).Results61/82 (74.4%) were livebirths, 5 (8.2%) lost for follow-up, 3 (4.9%) had compassionate care leaving 53 (64.6% of the whole cohort and 86.9% of livebirths) with intention to treat. 9 died, 44/53 (83.0%) survived. 24/38 (63.2%) with information on postnatal outcome had BV outcome, 14 (36.8%) non-BV outcome (2 × 1.5 circulation). One with BV outcome had prenatal valvuloplasty. Best single parameter for BV outcome was tricuspid/mitral valve (TV/MV) ratio (AUC 0.93) in intervals 2 and 3 (AUC 0.92). Ventriculo-coronary-arterial communications (VCAC) were present in 11 (78.6%) in non-BV outcome group vs. 2 (8.3%) in BV outcome group (p 2.5 m/s was present in BV outcome group in75.0% (18/24) vs. 14.3% (2/14) in non-BV outcome group. Including the most predictive markers (VCAC presence, TI- Vmax 1 criterion was fulfilled in all cases. After recently published criteria for foetal intervention, only 4/9 (44.4%) and 5/14 (35.7%) in our interval 2 + 3 with predicted non-BV outcome would have been candidates for intervention. Two (1 × intrauterine intervention) in interval 2, two in interval 3 reached BV outcome and one 1.5 circulation without intervention.ConclusionTV/MV ratio as simple parameter has high predictive value. After our score, non-BV outcome was correctly predicted in all cases. Criteria for foetal intervention must further be evaluated.

This study aimed to compare long-term morbidity in patients with pulmonary atresia with intact ventricular septum (PA-IVS) treated with catheter-based intervention (group A) versus those undergoing heart surgery (group B) as initial intervention. Additionally, we conducted a systematic literature review on PA-IVS treatment. All neonates born in Sweden with PA-IVS between 2007 and 2019 were screened for inclusion. The inclusion criterion was decompression of the right ventricle for initial intervention. Medical records were reviewed, as well as the initial preoperative angiogram, and the diagnostic echocardiogram. Comparisons between groups were performed with Mann-Whitney U-test and Fisher´s exact test. A systematic literature review of original studies regarding treatment of PA-IVS (2002 and onward) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, to assess the outcomes of patients with PA-IVS. 34 (11 females) patients were included, 18 in group A and 16 in group B. There was no mortality in either group. Follow-up time ranged from 2 to 15 years (median 9). All attempted perforations in group A were successful, and 16 out of 18 patients reached biventricular circulation. In the surgical group 15 out of 16 patients reached biventricular circulation. The literature review presented heterogeneity in standards for treatment. This retrospective population-based multicenter study demonstrates that both catheter-based intervention and heart surgery are safe procedures. Our results are comparable to, or exceed, those in the systematic literature review. The systematic literature review displays a great heterogeneity in study design, with no definitive golden standard treatment.