Endovascular Stenting of Obstructed Right Ventricle–to–Pulmonary Artery Conduits

Abstract

The optimal treatment for dysfunctional right ventricle-to-pulmonary artery (RV-PA) conduits is unknown. Limited follow-up data on stenting of RV-PA conduits have been reported. Between 1990 and 2004, deployment of balloon-expandable bare stents was attempted in 242 obstructed RV-PA conduits in 221 patients (median age, 6.7 years). Acute hemodynamic changes after stenting included significantly decreased RV systolic pressure (89+/-18 to 65+/-20 mm Hg, P<0.001) and peak RV-PA gradient (59+/-19 to 27+/-14 mm Hg, P<0.001). There were no deaths, and, aside from 5 malpositioned stents requiring surgical removal, there were no serious procedural complications. During follow-up of 4.0+/-3.2 years, 9 patients died and 2 underwent heart transplantation, none related to catheterization or stent malfunction. During 155 follow-up catheterizations in 126 patients, the stent was redilated in 83 patients and additional stents were placed in 41. Stent fractures were diagnosed in 56 patients (43%) and associated with stent compression and substernal location but did not cause acute hemodynamic consequences. By Kaplan-Meier analysis, median freedom from conduit surgery after stenting was 2.7 years (3.9 years in patients >5 years), with younger age, homograft conduit, conduit diameter < or =10 mm, diagnosis other than tetralogy of Fallot, Genesis stent, higher prestent RV:aortic pressure ratio, and stent malposition associated with shorter freedom from surgery. Tricuspid regurgitation and RV function did not change between stent implantation and subsequent surgery. Conduit stenting is an effective interim treatment for RV-PA conduit obstruction and prolongs conduit lifespan in most patients. Stent fractures were common but not associated with significant complications or earlier conduit reoperation.