CPT® Code 33694

1. Indications

The procedure is indicated for neonates diagnosed with tetralogy of Fallot, particularly in cases where a transannular patch is necessary to correct pulmonary stenosis. The following conditions warrant this surgical intervention:

• Tetralogy of Fallot (TOF) A congenital heart defect characterized by a combination of four specific heart abnormalities.
• Pulmonary Stenosis A narrowing of the pulmonary valve and outflow tract that obstructs blood flow from the right ventricle.
• Right Ventricular Hypertrophy Thickening of the muscular walls of the right ventricle due to increased pressure from the obstruction.
• Ventricular Septal Defect (VSD) One or more holes in the ventricular septum that can lead to mixing of oxygenated and deoxygenated blood.
• Overriding Aorta A defect where the aorta is positioned above the VSD, receiving blood from both ventricles.
• Pulmonary Atresia (if present) A complete obstruction of blood flow from the right ventricle to the pulmonary artery, necessitating additional surgical intervention.

2. Procedure

The surgical procedure for the complete repair of tetralogy of Fallot with a transannular patch involves several critical steps:

• Step 1: Median Sternotomy The surgeon begins by making a vertical incision along the sternum to access the heart. This approach allows for optimal visibility and access to the cardiac structures.
• Step 2: Establishing Cardiopulmonary Bypass Once the heart is exposed, cardiopulmonary bypass is initiated. This involves connecting the patient to a heart-lung machine that takes over the function of pumping blood and oxygenating it, allowing the heart to be temporarily stopped.
• Step 3: Cardioplegic Arrest The heart is then placed in a state of cardioplegic arrest, which is achieved by infusing a cold solution that temporarily halts cardiac activity. This protects the heart muscle during the repair process.
• Step 4: Repairing the Ventricular Septal Defect (VSD) The VSD is addressed by placing a synthetic patch over the defect. This closure prevents the mixing of oxygenated and deoxygenated blood between the ventricles and corrects the position of the overriding aorta.
• Step 5: Addressing Pulmonary Stenosis The narrowed pulmonary valve is treated by resecting obstructive tissue in the right ventricle. This step may involve the placement of a transannular patch, which requires making a long incision that traverses the pulmonary artery and valve to enlarge the outflow tract.
• Step 6: Creating a Conduit (if pulmonary atresia is present) If the neonate has pulmonary atresia, a conduit is constructed from the right ventricle to the pulmonary artery. This is done by incising the front surface of the right ventricle while carefully avoiding the coronary artery. One end of a synthetic tube is sutured to the right ventricle, and the other end is sutured at the bifurcation of the pulmonary arteries, allowing blood to flow to the lungs.

3. Post-Procedure

After the completion of the surgical repair, the neonate is closely monitored in a postoperative setting. The expected recovery involves careful observation for any complications, such as bleeding or infection. The patient may require support for respiratory function and will be assessed for cardiac output and overall stability. Follow-up care is essential to monitor the heart's function and ensure that the surgical repair is effective. Additional interventions may be necessary based on the individual patient's condition and response to the surgery.