Association of pulmonary conduit type and size with durability in infants and young children

Background: Treatment of congenital heart disease may include placement of a right ventricle to pulmonary artery conduit that requires future surgical replacement. We sought to identify surgeon-modifiable factors associated with durability (defined as freedom from surgical replacement or explantation) of the initial conduit in children less than 2 years of age at initial insertion.

Methods: Since 2002, 429 infants were discharged from 24 Congenital Heart Surgeons' Society member institutions after initial conduit insertion. Parametric hazard analysis identified factors associated with conduit durability while adjusting for patient characteristics, the institution where the conduit was inserted, and time-dependent interval procedures performed after conduit insertion but before replacement/explantation.

Results: In all, 138 conduit replacements (32%) and 3 explantations (1%) were performed. Conduit durability at a median follow-up of 6.0 years (range, 0.1 to 11.7) was 63%. After adjusting for interval procedures and institution, placement of a conduit with smaller z-score was associated with earlier replacement/explantation (p = 0.002). Moreover, conduit durability was substantially reduced with aortic allografts (p = 0.002) and pulmonary allografts (p = 0.03) compared with bovine jugular venous valved conduits (JVVC). The JVVC were 12 mm to 22 mm in diameter at insertion (compared with 6 mm to 20 mm for allografts); therefore, a parametric propensity-adjusted analysis of patients with aortic or pulmonary allografts versus JVVC with diameter of 12 mm or greater was performed, which verified the superior durability of JVVC.

Conclusions: Pulmonary conduit type and z-score are associated with late conduit durability independent of the effects of institution and subsequent interval procedures. Surgeons can improve long-term conduit durability by judiciously oversizing, and by selecting a JVVC.