Transcatheter pulmonary valve implantation is a technique is applied to patients with prior repair of congenital heart disease and right ventricular outflow tract (RVOT) dysfunction. Right ventricular outflow tract (RVOT) dysfunction is a term given to abnormalities of the pulmonary valve and the right ventricular outflow tract. It often occurs as part of complex congenital heart conditions, such as tetralogy of Fallot. During RVOT, blood flows abnormally between the heart and lungs and if left untreated, can be a life-limiting condition.
Biological valves tend to degenerate after 10-20 years and become stenotic or insufficient. Due to the fact that they are generally inserted in younger individuals, the need for one or two operations is necessary throughout that individual’s lifetime. Percutaneous pulmonary valve replacement may be a good option for patients who are either poor candidates for open heart surgery or the surgery itself is of high risk due to the medical condition in question.
Before undergoing percutanous pulmonary valve replacement, it is important for the patient to:
- Consult with a doctor about risks associated with the surgery
- Inform the doctor of any medical problems (allergies)
- Have tests done (echocardiogram, blood samples)
- Stop taking any medications three days before the procedure to reduce the risk of bleeding
- Arrange for transportation to and from the hospital
Percutaneous pulmonary valve replacement is not recommended for women who are pregnant, individuals with occluded central veins, an active infection or individuals who are overweight.
During this percutanous pulmonary valve replacement, general anesthesia is used so that the patient is unconscious during the procedure. The valve is implanted through a catheter (a narrow tube) and inserted through the femoral vein into the right atrium, right ventricle and pulmonary artery. Before situating the valve, a stent (wire mesh tube) is typically positioned into the pulmonary artery or conduit in order to allow better securing of the valve into proper position. After careful positioning, the valve is implanted by inflating a set of two balloons on the delivery catheter. After the catheter has been removed, the incision is closed with stitches, which are removed after the area has healed.
Possible complications that can arise from percutaneous pulmonary valve replacement include the following:
- Stent fractures
- Re-intervention (second stent in stent PPVI)
- Bruising where the catheter was inserted
Following the procedure, staying overnight at the hospital is recommended in order to ensure the valve is working properly and monitor for any unwanted changes or complications. Side effects such as vomiting, sore throat, headache and dizziness may occur after the procedure; however, they are usually short-lived and not severe.
Once discharged, it is necessary for the patient to get plenty of rest and avoid participation in any contact sports such as football, which can affect the stent (possibly through a direct hit to the chest). If more serious symptoms such as difficulty breathing, high temperature, infection, poor appetite or weight loss occur, it is important to contact a doctor right away.
With evolving medical knowledge and technique modification, PPVI reduces the number of operations needed for children and young adults, and potentially improves the life expectancy in patients with congenital heart disease that involve the RVOT.