Interventional therapy of supravalvular pulmonary stenosis via a mechanical valve in the pulmonary position

There is an increasing number of patients with congenital heart disease and pathology of the right ventricular outflow tract in whom a mechanical pulmonary valve replacement is chosen for permanent palliation. Despite corrective surgery, some of these patients may have residual or secondary supravalvular pulmonary stenosis or peripheral pulmonary stenosis, which necessitate interventional therapy after valve replacement. There is a general understanding that interventional therapy via a mechanical valve in pulmonary position may induce mechanical valve dysfunction and should therefore be avoided. We report our experience in three patients with a St. Jude Medical mechanical valve in pulmonary position and supravalvular pulmonary stenosis or a peripheral pulmonary stenosis where we have safely performed standard interventions (i.e., balloon angioplasty and stent implantation) across the mechanical valve without any complications. Our specific technique using a long sheath as safety guard, which holds the mechanical valve open during the procedure but allows the positioning of all mechanical devices and catheters necessary for the procedures, is described. In all patients, the long-term follow-up of the valve function is excellent.