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Intravascular stent prosthesis for right ventricular outflow obstruction
M C Hosking1, L N Benson, T Nakanishi
1Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.
Insights
Balloon-expandable stents effectively treated right ventricular outflow obstruction in children with congenital heart disease, improving pulmonary artery stenosis and conduit obstruction. This shows stenting is a valuable tool for pediatric cardiovascular care.
Area of Science:
- Pediatric Cardiology
- Interventional Cardiology
- Congenital Heart Disease Management
Background:
- Intravascular stenting is established for adult vascular disease.
- Limited data exists for pediatric applications, especially in right ventricular outflow obstruction.
- Balloon angioplasty may be insufficient for complex pediatric obstructions.
Purpose of the Study:
- To evaluate the efficacy of balloon-expandable stents.
- To assess impact on right ventricular outflow obstruction in pediatric congenital heart disease.
- To determine safety and outcomes of stenting in this population.
Main Methods:
- Implantation of 24 stainless steel stents in 17 pediatric patients.
- Stents placed in right ventricular to pulmonary artery conduits, branch pulmonary arteries, and aortopulmonary collateral vessels.
- Follow-up included hemodynamic and angiographic assessment up to 14 months.
Main Results:
- Successful stent placement in 22 of 24 cases; no embolization or thrombosis.
- Significant reduction in RV-to-PA conduit gradients (85 to 35 mm Hg).
- Pulmonary artery stenosis showed marked diameter increase (92%) and gradient reduction (22 to 3 mm Hg), with clinical improvement in 10/11 patients.
Conclusions:
- Intravascular stenting is a safe and effective adjunct for managing pediatric congenital heart disease.
- Stenting significantly improves obstruction in RV-to-PA conduits and pulmonary arteries.
- Further research is warranted to establish long-term outcomes.
Objectives:
This study was designed to assess the impact of implantation of balloon-expandable stents on right ventricular outflow obstruction in children with congenital heart disease.
Background:
Intravascular stenting has been established as a useful treatment in adults with coronary and peripheral vascular disease. Its application in the treatment of infants and children with pulmonary, systemic and right ventricular conduit obstruction resistant to balloon angioplasty is limited.
Methods:
A total of 24 stainless steel stents were implanted in 17 patients. Five stents were placed within right ventricular to pulmonary artery conduits, 17 in branch pulmonary arteries and 1 in an aortopulmonary collateral vessel. Follow-up time has ranged from 1 to 14 months, with 6 patients having hemodynamic and angiographic studies greater than 1 year after stent placement. The mean age at implantation was 7.4 +/- 5.6 years and the mean weight 33 +/- 16 kg.
Results:
Optimal stent position was obtained in 22 of 24 implantations. In one patient the stent slipped from the delivery balloon and was left positioned in the inferior vena cava. No embolization or thrombotic event has been documented. Among patients with right ventricular to pulmonary artery conduit obstruction, the gradient was immediately reduced from 85 +/- 30 mm Hg to 35 +/- 20 mm Hg after stent implantation; however, three patients required conduit replacement because of persistent obstruction with elevated right ventricular pressures (82 +/- 16 mm Hg). In 10 of 11 patients with pulmonary artery stenosis, clinical improvement was noted in association with enlargement of vessel diameter by 92% +/- 90% (range 17% to 355%) and the gradient reduction of 22 +/- 24 mm Hg to 3 +/- 4 mm Hg.
Conclusions:
These data support the view that intravascular stenting will become an important adjunct in the management of children with congenital heart disease.