Which type of conduit to choose for right ventricular outflow tract reconstruction in patients below 1 year of age?

Abstract

Reconstruction of the right ventricular outflow tract (RVOT) with a conduit in patients below 1 year of age remains a matter of concern due to limited availability and durability of conduits. We sought to analyse the freedom from conduit exchange in this subgroup of patients by comparing different conduits. Data of 145 consecutive patients below 1 year of age, requiring a conduit for RVOT reconstruction between 1994 and 2011 were reviewed. The endpoints of the study were defined as: 'conduit exchange for any reason', 'at least moderate conduit stenosis' and 'at least moderate insufficiency'. Homografts, bovine jugular vein conduits (Contegra) and porcine-valved Dacron conduits (Hancock) were implanted in 62 (43%), 35 (24%) and 48 (33%) patients, respectively. The mean conduit diameter was 12.9 ± 1.3 mm. A conduit exchange was necessary in 72 patients (55%) at a median time of 5.9 years [1.1-10.8]. The rate of freedom from conduit exchange at 5 years was 69.4 ± 6.6, 59.4 ± 8.7 and 53.8 ± 7.4%, respectively (P = 0.4). The rate of freedom from at least moderate stenosis was 85.4 ± 5.6, 75.1 ± 9.1 69.1 ± 7.9% at 5 years and 59.2 ± 11.1, 35.8 ± 12.0, 49.7 ± 10.1% at 10 years, for homografts, Contegra and Hancock conduits, respectively. The rate of freedom from at least moderate conduit insufficiency was 91.7 ± 4, 74.6 ± 9.1, 86.9 ± 7.4% at 5 years and 64.8 ± 14.1, 44.2 ± 13.7, 52.1 ± 14.2% at 10 years, for homografts, Contegra and Hancock conduits, respectively. Patients with a Contegra conduit developed moderate conduit stenosis or insufficiency faster than patients with a homograft (P = 0.01). Age below 1 month and heterotopic implantation of the conduit emerged as risk factors for conduit exchange in the univariate analysis (P = 0.05, P = 0.02, respectively). There was no significant influence of the conduit type, conduit size, z-score or the body surface area. In the multivariate analysis, heterotopic implantation emerged as the only risk factor for conduit exchange (P = 0.02, hazard ratio = 1.6, 95% confidence interval = 1.0-2.7). Homografts, bovine jugular vein conduits and porcine-valved Dacron conduits exhibit equal durability after implantation in patients below 1 year of age independent of their size. Nonetheless, moderate conduit stenosis or insufficiency develops earlier in patients with a Contegra conduit. Conduit placement in the neonatal period and implantation in a heterotopic position shortens the durability.