Mixed type of total anomalous pulmonary venous connection: diagnosis, surgical approach and outcomes

PURPOSE: To summarize the diagnosis and treatment of 13 patients with mixed-type total anomalous pulmonary venous connection (TAPVC) and propose another classification for mixed TAPVC. METHODS: A retrospective review of 13 patients with mixed TAPVC undergoing repair at a single institution was conducted between January 2010 and November 2019. The diagnosis of mixed-type TAPVC was made in all patients using echocardiography combined with computed tomography angiography. According to the mixed TAPVC anatomy, there were 3 patients with type I TAPVC (2 + 2 veins), 10 patients with type II TAPVC (3 + 1 veins) and no patients with type III TAPVC. Correspondingly, there was 1 patient with the “SVC + VV” subtype, 2 patients with the “CS + C” subtype, 8 patients with the “CS + VV” subtype, 1 patient with the “CS + SVC” subtype and 1 patient with the “RA + SVC” subtype according to our classification system. All patients underwent cardiopulmonary bypass surgery. RESULTS: The median weight at surgery was 4.6 ± 1.0 kg (3.4–7.3 kg), and the median age at surgery was 96.2 ± 81.2 days (10–242 days). The median cardiopulmonary bypass time was 132.7 ± 25.1 min (range, 100 to 190 min). The cross-clamping time was 69.2 ± 14.4 min (range, 45 to 88 min). The hospital mortality rate was 7.7% (1 of 13), with late mortality occurring in 1 patient because of pulmonary venous obstruction (PVO) 7 months after surgery. The average follow-up after surgery was 3.4 ± 2.2 years (range, 5 months to 8 years). The survival rates at 3 and 5 years were both 90.9% ± 8.7% (95% CI: 73.8–108%). All remaining surviving patients were asymptomatic. CONCLUSION: Mixed TAPVC can be repaired with good results in children and can be correctly diagnosed with echocardiography combined with computed tomography angiography. The classification system we propose is pragmatic and can guide the surgical approach.