Repeat dilation of intravascular stents in congenital heart defects

Intravascular (Palmaz) stents have been successfully implanted in patients with congenital and acquired branch pulmonary stenosis. Early results are excellent; however, there is no information on restenosis and repeat dilation in patients with congenital heart disease. The purpose of this study is to review the incidence of restenosis and demonstrate the safety and efficacy of repeat dilation of stents in this group of patients.

Of 94 patients with 163 implanted stents in this single-center study, 43 patients with 73 implanted stents underwent recatheterization. Only 2 of 73 restudied stents (3%) developed significant restenosis. In 20 patients, 30 stents were redilated. At stent implantation, the mean age of this subgroup was 14.2 years, the mean intraluminal diameter increased from 4.9 to 10.7 mm (P = .0001), and the systolic gradient (mean) across the stent decreased from 52 to 11 mm Hg (P = .0001). At recatheterization (mean, 13 months), all stents were patent. The mean diameter decreased by 1.2 mm (P = .0001), but the increase in the gradient (mean, 3 mm Hg) was not significant (P = .11). After repeat dilation, the diameter increased from 9.5 to 12.2 mm (P = .0001), and the gradient decreased from 14 to 8 mm Hg (P = .0003). The 2 stents with restenosis were redilated successfully. Two patients underwent a successful second redilation of 3 stents at 18 and 26 months. There were no complications.

All stents remained patent. The occurrence of significant restenosis is low (3%), and these restenoses can be redilated and/or restented. Repeat dilation of the Palmaz stent implanted in branch pulmonary artery stenosis can be performed with safety and efficacy (94% success rate) up to 3 years after stent implantation.