Prenatal diagnosis of total and partial anomalous pulmonary venous connection: multicenter cohort study and meta‐analysis

Objectives Aim of this study is to describe the sonographic features and associations of Total and Partial Anomalous Pulmonary Venous Connection (TAPVC, PAPVC) and scimitar syndrome (SS) and to review the relevant literature systematically in order to underline the associations and the sonographic features more frequently associated with these conditions. Methodology Retrospective cohort study. Assessed variables include: TAPVC subtype, gestational age at diagnosis, area behind LA, ventricular disproportion, vertical vein, pulmonary venous obstruction, mode of diagnosis, association with cardiac and extra-cardiac conditions, pregnancy and feto-neonatal outcome. The outcome was considered favourable if the individual was alive and in good conditions (no functional impairment from surgery or from cardiac and extra-cardiac conditions). Cases associated with right isomerism were excluded from the analysis, considering that TAPVC in these cases was only one of several major cardiac anomalies having an effect on the sonographic signs. A systematic review was performed in order to obtain a synthesis of the characteristics associated with TAPVC, PAPVC and SS. A meta-analysis was finally conducted only for TAPVC. The literature search (1970–2016) included reviews, case series and case reports available in PubMed and Embase. The Random Effects Models was used to obtain pooled estimates of the frequency of their clinical characteristics and sonographic features. Results TAPVC A total of 15 studies and 71 patients (including 13 of the cohort study) were included in the systematic review and meta-analysis. The pooled estimate of the association between TAPVC and CHD was 28.3% (95% CI: 18.1%-41.3%), between TAPVC and extra-cardiac anomalies 18.5% (95% CI: 10.5%-30.6%). An obstructed venous return was observed in 34.1% of the cases (95% CI: 22.7%-47.7%). A favourable outcome was recorded in 43.8% (95% CI: 24.0%-65.8%). Ventricular Disproportion was present in 59.2% (95% CI: 45.1%-72.0%) of the cases. An increased area behind the LA was observed in 58.1% (95% CI: 41.1%-73.5%). A vertical vein was detected in 59.3% (95% CI: 41.1%-75.3%). The diagnosis was established in most of the cases through color or power Doppler: 84.9%; (95% CI: 67.3%-93.9%). SS There were only 3 studies describing 8 cases, to which we added 5 cases. Ventricular disproportion was present in 3/9 cases, but in two of these a concurrent heart anomaly was associated. Color Doppler was always employed for diagnosis, and 4D-echocardiography was useful in 2/6 cases in which it was used. Outcome was generally good. PAPVC There were only 5 studies describing 5 cases, to which we added 2 more. Major cardiac anomalies were associated in 4/7 cases, extra-cardiac anomalies in 3/6. Conclusions 1. TAPVC can be associated with other cardiac and extracardiac anomalies in a significant percentage of cases. 2. Leading sonographic signs are: ventricular disproportion, an increased area behind LA and the recognition of a vertical vein. Color/Power Doppler is the key diagnostic mode for diagnosis. An obstructed venous return can be expected in roughly one third of the cases. Outcome is favourable in less than half of the cases. The data for SS and PAPVC are very limited.