The aim of our study was to compare post-operative outcome after total cavopulmonary connection between patients operated during winter and summer season.

We retrospectively studied 211 patients who underwent extracardiac total cavopulmonary connection completion at our institution between 1995 and 2015 (median age 4 (1–42) years). Seventy (33%) patients were operated during winter (November to March) and 141 (67%) patients during summer season (April to October).

Patients operated during winter and summer season showed no difference in early mortality (7% versus 5%, p = 0.52) and severe morbidity like need for early Fontan takedown (1% versus 1%, p = 0.99) and need for mechanical circulatory support (9% versus 4%, p = 0.12). The post-operative course and haemodynamic outcome were comparable between both groups of patients (ICU (4 versus 3 days, p = 0.44) and hospital stay (15 versus 14 days, p = 0.28), prolonged pleural effusions (36% versus 31%, p = 0.51), need for dialysis (16% versus 11%, p = 0.37), ascites (37% versus 33%, p = 0.52), supraventricular tachyarrhythmia (16% versus 13%, p = 0.56) and chylothorax (26% versus 16%, p = 0.12), change of antibiotic treatment (47% versus 36%, p = 0.06), prolonged inotropic support (24% versus 14%, p = 0.05), intubation time (15 versus 12 hours, p = 0.33), and incidence of fast-track extubation (11% versus 22%, p = 0.06).

Outcomes after total cavopulmonary connection completion during winter and summer season were comparably related to mortality, severe morbidity, or longer hospital stay in the early post-operative period. These results suggest that total cavopulmonary connection completion during winter season is as safe as during summer season.