Right ventricular outflow tract obstruction overview

Associate Editors-In-Chief: ; Keri Shafer, M.D. [mailto:kshafer@bidmc.harvard.edu]

Right ventricular outflow tract (RVOT) and/or pulmonary artery obstruction are present in some form in 25 % of all congenital heart defects. The right ventricular outflow tract obstruction includes stenosis or narrowing of the pulmonary valve, the tissue above the valve (supravalvar obstruction) and below it(subvalvar obstruction). Congenital subvalvar and supravalvar right ventricular outflow tract stenosis usually occurs with other congenital heart defects such as Ventricular Septal Defect (VSD) or Tetralogy of Fallot. The timing and type of surgery will vary from patient to patient depending upon the severity of the obstruction and the associated congenital defect.

If right ventricular outflow tract obstruction is present and the ventricular septum is intact, usually the right ventricle will adapt better given that no right to left shunting is present. This absence of shunting may result in sufficient pulmonary blood flow to allow the patient to remain asymptomatic longer.

Usually therapy is directed to increase pulmonary blood flow and decompressing the right ventricle (RV) and it will depend on the severity and location of the defect. According to the anatomic features of the pulmonary valve stenosis, the physician may use balloon dilatation (a minimally invasive transvenous procedure) to dilate the obstruction during cardiac catheterization, but if the pulmonary artery is the structure involved, stenting (insertion of a small tube) within the narrowed region can be done following balloon angioplasty. Standard treatment of right ventricular outflow tract or pulmonary artery obstruction involves open chest surgery.