Endovascular stenting of obstructed right ventricle-to-pulmonary artery conduits - A 15-year experience

Background - 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. Methods and Results - 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 <= 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. Conclusions - 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.