Percutaneous double-balloon angioplasty of a stenotic modified Fontan aortic homograft conduit

Partial and transient relief of conduit obstruction by low-pressure balloon dilation in patients with congenital heart disease

Seven patients underwent attempted low pressure balloon dilation of stenotic conduits or homografts from right ventricle to pulmonary artery (n = 5), in the aortic valve position (n = 1), or from right atrium to left pulmonary artery (n = 1). In the right ventricle to pulmonary artery group, mean gradient reduction was only 17%. At follow-up, two patients underwent surgical conduit replacement, one had a stent implanted at cardiac catheterization, the other two are awaiting surgical intervention. The patient with a homograft in the aortic valve position had a good initial result but restenosed within 1 year and underwent a pulmonary autograft operation. The patient with the Fontan homograft stenosis had transient obstruction relief but subsequently required stent implantation. Low-pressure balloon dilation of conduits or homografts is only partially and transiently successful. Whether stent implantation will offer better long-term results remains to be determined.

Balloon dilatation of a stenosed aortic homograft conduit following repair of the common arterial trunk

An 8-year-old boy, who underwent surgical correction of a common arterial trunk at the age of 10 months, developed stenosis of the 15-mm aortic homograft. Chest x-ray demonstrated calcification of the homograft, and at cardiac catheterization there was a 57 mmHg gradient across the conduit. He underwent balloon dilatation using a 15-mm balloon catheter. After four inflations at a pressure of 5.5 atm, the gradient decreased to 34 mmHg. Six months later he had a Doppler-estimated gradient of 38 mmHg.

Balloon dilation of postoperative right ventricular outflow obstructions

Balloon dilation was attempted in 16 patients, aged 5 months to 19.5 years, with right ventricular outflow obstruction after repair of congenital heart defects. Stenosis of a valved conduit between the pulmonary ventricle and pulmonary artery was present in nine patients with a mean transvalvular peak systolic ejection gradient of 61.6 +/- 21.0 mm Hg and a mean right ventricle to aorta pressure ratio of 0.9 +/- 0.2. Supravalvular pulmonary stenosis was present in seven patients; in five, stenosis was at the anastomotic site after the arterial switch operation with a mean peak systolic ejection gradient of 72.2 +/- 10.6 mm Hg and mean right ventricle to aorta pressure ratio of 0.93 +/- 0.05. The other two patients had stenosis at a previous pulmonary artery band site with a peak systolic ejection gradient of 60 and 65 mm Hg and right ventricle to aorta pressure ratio of 0.75 and 0.72, respectively. Balloon dilation was successful in three of nine patients with a valved conduit; two of them had additional successful balloon dilation of the right pulmonary artery. In five of the nine patients (including one with successful dilation) the conduit was replaced 5.7 +/- 4.5 months after balloon dilation. Balloon dilation was successful in only one of the five patients with supravalvular pulmonary stenosis after the arterial switch operation and partially successful in the two patients with supravalvular pulmonary stenosis at a previous band site. The success rate of balloon dilation of postoperative right ventricular outflow obstruction is much lower than that for other right heart obstructions.