The National Institute for Health and Clinical Excellence (NICE) has issued full guidance to the NHS in England, Wales, Scotland Northern Ireland on balloon dilatation with or without stenting for pulmonary artery or non-valvar right ventricular outflow tract obstruction in children.
The right ventricular outflow tract includes the pulmonary valve and the tissue above and below it. Narrowing (stenosis) of this region may involve the area below the valve (subvalvar), the valve itself (valvar) or the area above the valve (supravalvar). Balloon angioplasty of valvar right ventricular outflow tract narrowing (pulmonary valve stenosis) is covered in a separate overview.
Congenital subvalvar and supravalvar right ventricular outflow tract stenosis usually occurs with other cardiac defects such as ventricular septal defect or tetralogy of Fallot. Postoperative right ventricular outflow tract obstruction may occur after surgery to create a conduit between the right ventricle and pulmonary artery in children with congenital anomalies.
Narrowing may also occur beyond the right ventricular outflow tract, in one of the pulmonary arteries, or in their branches. This may also be congenital or occur following surgery for congenital defects.
Balloon dilatation is a minimally invasive transvenous procedure to dilate the obstruction during cardiac catheterisation. Stenting involves the insertion of a small tube within the narrow region following balloon angioplasty. Standard treatment of right ventricular outflow tract or pulmonary artery obstruction involves open chest surgery.