Intravascular Stents in Congenital Heart Disease: Short- and Long-Term Results From Large Single-Center Experience

Objectives. This report describes the results of the Food and Drug Administration’s phase 1 and 2 clinical trials of intravascular stents at Texas Children’s Hospital. Background. Since the late 1980s, intravascular stent implantation for the treatment of arterial and venous stenoses in congenital heart disease has been highly successful. Methods. Stents were placed in postoperative pulmonary artery (PA) stenoses, congenital P stenoses or stenoses of systemic veins/venous anastomoses. Prospective collection of dat according to protocol was done before intervention, after stent implantation and at follow-up catheterization. Results. At stent implantation, pressure gradients decreased significantly in all three groups (mean ± SD): from 46 ± 25 to 10 ± 13 mm Hg in postoperative P stenoses (p < 0.001); from 71 ± 45 to 15 ± 21 mm Hg in congenital P stenoses (p < 0.001); and from 7 ± 6 to 1 ± 2 mm Hg in stenoses of systemic veins/venous anastomoses stenoses (p < 0.001). Vessel diameters markedly increased: from 6 ± 3 to 12 ± 3 mm in postoperative P stenoses (p < 0.001); from 3 ± 1 to 9 ± 1 mm in congenital P stenoses (p < 0.001); and from 3 ± 4 to 12 ± 4 mm in stenoses of systemic veins/venous anastomoses (p < 0.001). In the postoperative and congenital P stenoses groups, right ventricular pressure decreased (right ventricular pressure indexed to femoral artery pressure ratio): from 0.63 ± 0.2 to 0.41 ± 0.02 (p < 0.001) and from 0.71 ± 0.3 to 0.55 ± 0.35 (p = 0.04), respectively. Perfusion to single affected lung increased from 31 ± 17% to 46 ± 14% (p < 0.001). On recatheterization (mean 14 months), results varied minimally. Repeat angioplasty of residual stent stenoses was safe and effective. Complications included four early patients with stent migration, three with stent thrombosis and two deaths. There were no late complications. Significant restenosis occurred in only three patients. Conclusions. Intravascular stents for the treatment of vascular stenoses in congenital heart disease provide excellent immediate and long-term results.