CPT® Code 33621

1. Indications

The transthoracic insertion of a catheter for stent placement, as described by CPT® Code 33621, is indicated for patients with specific congenital cardiac anomalies. These include:

• Hypoplastic Left Heart Syndrome A congenital heart defect characterized by underdevelopment of the left side of the heart, necessitating staged surgical interventions to ensure adequate blood flow and oxygenation.
• Other Cardiac Anomalies Conditions that may require similar interventions to manage blood flow and support cardiac function until definitive surgical repair can be performed.

2. Procedure

The procedure involves several critical steps to ensure successful stent placement:

• Step 1: Surgical Exposure The heart is accessed through a limited left anterior or lateral thoracotomy, or less commonly, a median sternotomy. This initial incision allows the surgeon to gain access to the thoracic cavity and the heart.
• Step 2: Pericardial Incision Once the thoracic cavity is opened, the pericardium, which is the protective sac surrounding the heart, is incised. This step is essential for exposing the heart and the major blood vessels.
• Step 3: Thymus Retraction The thymus gland is retracted to provide a clear view of the aorta and pulmonary arteries, which are critical structures for the subsequent steps of the procedure.
• Step 4: Incision in the Main Pulmonary Artery A small incision is made in the main pulmonary artery to facilitate the advancement of the catheter. This incision is strategically placed to allow for optimal access to the ductus arteriosus.
• Step 5: Catheter Advancement A balloon catheter, which is equipped with a stent covered by a sheath, is advanced through the main pulmonary artery and into the ductus arteriosus. This step requires careful navigation to ensure proper placement.
• Step 6: Stent Positioning and Deployment The stent is carefully positioned within the ductus arteriosus. Once in place, the sheath covering the stent is removed, and the stent is deployed. This deployment is critical for establishing a stable conduit for blood flow.
• Step 7: Balloon Inflation The balloon catheter is inflated to ensure full expansion of the stent, securing it in place across the ductus arteriosus. This inflation is vital for the stent's functionality and effectiveness in maintaining blood flow.

3. Post-Procedure

After the procedure, careful monitoring is essential to assess the patient's recovery and the functionality of the stent. Post-procedure care may include observation for any complications, management of pain, and ensuring that the patient is stable. The stent serves as a temporary solution, providing a conduit to the aorta until a definitive surgical repair of the heart defect can be performed. Follow-up evaluations will be necessary to determine the timing and approach for subsequent surgical interventions.