Impact of veno-venous collaterals on outcome after the total cavopulmonary connection

Objective: To evaluate the prevalence of veno-venous collaterals (VVCs) after total cavopulmonary connection (TCPC) and analyze their impact on outcomes. Methods: Patients undergoing TCPC between 1994 and 2022 were evaluated. VVCs were identified using angiograms of cardiac catheterizations and their impact on outcomes was analyzed. Results: A total of 635 patients were included. Median age at TCPC was 2.3 (interquartile ranges (IQR): 1.8–3.3) years. The most frequent diagnosis was hypoplastic left heart syndrome in 173 (27.2%) patients. Prior bidirectional cavopulmonary shunt was performed in 586 (92.3%) patients at a median age of 5.3 (3.6–9.9) months. VVCs were found in 94 (14.8%) patients at a median of 2.8 (0.1–11.8) years postoperatively. The prevalence of VVCs was similar between the dominant right and left ventricle (14.7 vs. 14.9%, p = 0.967). Mean pulmonary artery pressure (16.2 vs. 16.0 mmHg, p = 0.902), left atrial pressure (5.5 vs. 5.7 mmHg, p = 0.480), transpulmonary gradient (4.0 vs. 3.8 mmHg, p = 0.554) and oxygen saturation (81.4 vs. 82.6%, p = 0.103) before TCPC were similar between patients with and without VVCs. The development of VVCs did not affect survival after TCPC (p = 0.161). Nevertheless, VVCs were a risk for the development of plastic bronchitis (PB, p < 0.001). Interventional closure of VVCs was performed in 60 (9.4%) patients at a median of 8.9 (0.6–15.1) years after TCPC, and improvement of oxygen saturation was observed in 66% of the patients. Conclusions: The prevalence of VVCs after TCPC was 15%. VVCs had no impact on survival following TCPC but were associated with a high prevalence of PB.