Materials and methods
This was a single-centre, retrospective study approved by the Institutional Review Board of our hospital. All patients who underwent surgical repair of PAPVC associated with sinus venosus ASD between 1990 and 2019 were identified. Patients presenting with PAPVC and no sinus venosus ASD or with other associated significant congenital heart anomalies were excluded from the study, whereas patients with associated minor abnormalities such as persistent left SVC or bicuspid aortic valve were included. Surgical procedures and all reported postoperative complications were reviewed, while follow-up data were obtained from hospital records. The reports of the last echocardiogram performed were evaluated to identify any residual shunt or SVC obstruction. Electrocardiograms (ECG) including Holter ECG were reviewed to detect rhythm disturbances, which were classified as follows: sinus nodal dysfunction (SND), defined as “persistent sinus bradycardia inappropriate to hemodynamic requests”, frequently in the form of brady-tachy syndrome (16); ectopic atrial rhythm (EAR) likely caused by iatrogenic SA node injury; atrio-ventricular (AV) block, ventricular arrhythmias and atrial fibrillation (AF). According to the timing of their occurrence, rhythm disturbances were divided in early-onset and late-onset, as to whether they developed within 30 days after surgery or over 30 days post-surgery, respectively.
Surgical repair
All procedures were carried out through a median sternotomy, under moderate hypothermic cardiopulmonary bypass (CPB). Cold blood antegrade cardioplegia was used in all cases. Glutaraldehyde-treated autologous pericardial patches were employed to perform ASD closure, PVs rerouting and cavo-atrial junction enlargement, when required. In a single case of Warden procedure, a direct SVC-right atrial appendage anastomosis was performed to correct the upper venous drainage. The surgical technique for the PAPVC repair was chosen according to the site of abnormal drainage of the PVs. When the connection was at the level of the superior cavo-atrial junction close to the ASD, a single-patch repair was performed. Conversely, when the anomalous PVs drained into the SVC, well above the cavo-atrial junction, a double-patch repair was preferred in nearly all cases, except from a single Warden procedure which was performed in view of surgeon’s personal preference. In all cases, surgical access to the right atrium was obtained through a longitudinal atriotomy parallel to the atrioventricular groove, or through an L-shaped atriotomy. In patients where an extensive superior cavo-atrial enlargement was required (double-patch group), the incision was carried out as close as possible to the site of PVs connection to the SVC, in order to limit iatrogenic damage to the SA node. When single-patch technique was adopted instead, a more limited superior cavo-atrial incision was performed.
Data analysis
Continuous variables are expressed as mean ± standard deviations or as median and interquartile ranges, while categorical variables are expressed as absolute numbers and percentages. Analysis of continuous variables was performed by analysis of variance (ANOVA) test or Mann Whitney test, as appropriate. The Pearson’s chi-square test and the t-test were used to analyze categorical variables.
A p value < 0.05 was considered statistically significant.