The effect of the conduit size on middle-term outcomes in patients with extracardiac total cavopulmonary connection

OBJECTIVES: The 18- and 16-mm conduits in extracardiac total cavopulmonary connection (eTCPC) were reported to be optimal based on energy loss and flow stagnation at the relatively early phase. However, because the artificial conduit lacks growth potential, we have recently encountered some cases in which the conduit needs to be changed several years after eTCPC. These cases prompted us to reconsider the surgical strategy for eTCPC. METHODS: We reviewed our 20-year single-centre experience with eTCPC patients (n ¼ 256) to compare the 18-mm conduit (n ¼ 195) and 16-mm conduit (n ¼ 61) in terms of mortality and morbidity. RESULTS: The 16-mm conduit was used significantly more frequently in patients whose main chamber was right ventricle (P < 0.001). There was also a significant difference in preoperative inferior vena cava pressure (P ¼ 0.008). There was a significant difference in the actuarial rate of freedom from late-occurring complications, including mortality, between the 2 groups (P ¼ 0.003). There was a significant difference in the actuarial rate of reoperation-free survival (P ¼ 0.042); however, there was no significant difference in resurgical intervention for the conduit (P ¼ 0.333). In multivariate analysis, preoperative inferior vena cava pressure was an independent predictor for late-occurring complications (hazard ratio 1.19; P ¼ 0.026). Conduit size (18 or 16 mm) itself was not an independent predictive factor for late-occurring complications (P ¼ 0.690). CONCLUSIONS: The mid-term clinical outcomes in patients who underwent eTCPC were excellent with low mortality. Preoperative inferior vena cava pressure was the only predictive risk factor for postoperative morbidity, and the 16 mm conduit was not predictive thereof.