Right Ventricular Outflow Tract (RVOT) Stenting
What is RVOT?
The right ventricular outflow tract or RVOT is the part of the heart that directs blood to the lungs. This includes a part of the right ventricle, the pulmonary valve and pulmonary artery. This pathway is narrow in selected heart conditions. The best example is Tetralogy of Fallot.
Why stent the RVOT?
In children with congenital heart defects like Tetralogy of Fallot (TOF) the right ventricular outflow tract is extremely narrow with minimal forward flow.
The ideal treatment for TOF is complete correction wherein the RVOT obstruction is relieved surgically and the defect between the two ventricles (VSD) is closed. However, in selected situations, corrective surgery may not be possible. Typically this is in very young children or in patients with some other challenges that do not allow corrective surgery.
In these patients a stent may be placed in the narrow RVOT to improve flow to the lungs as a temporary measure until definitive surgery can be undertaken.
Since this procedure can be undertaken in the catheterization laboratory it is increasingly preferred over the traditional shunt surgery (Blalock-Taussig or BT shunt)
What to expect after the procedure?
There is often a visible improvement in the oxygen levels after the procedure and the benefits can last 3-6 months.This allows time for the child to grow until surgery can be performed with greater safety.
What are the complications?
The procedure is not without risk. There is a small risk of severe narrowing because of muscle spasm during the procedure and this may necessitate emergency shunt surgery. The stent may slip after deployment and this too may necessitate surgery. Sometimes the RVOT may open widely and result in uncontrolled and excessive blood flow to the lungs. This may require mechanical ventilation and several days ICU stay.