CPT® Code 33775

1. Indications

The procedure described by CPT® Code 33775 is indicated for patients diagnosed with transposition of the great arteries, particularly when associated with other cardiac anomalies such as:

• Ventricular Septal Defect (VSD) - An abnormal opening in the ventricular septum that allows for the mixing of oxygen-rich and oxygen-poor blood.
• Subpulmonary Stenosis - A narrowing of the main pulmonary artery just below the pulmonary valve, which can complicate the surgical repair of transposition.

2. Procedure

The surgical procedure for CPT® Code 33775 involves several critical steps to effectively repair transposition of the great arteries:

• Step 1: Accessing the Heart - The procedure begins with access to the heart, typically achieved through a median sternotomy or thoracotomy. This allows the surgeon to reach the heart and surrounding structures effectively.
• Step 2: Thymus Resection - The thymus gland is resected to provide better access to the heart and to facilitate the surgical procedure.
• Step 3: Incising the Pericardium - The pericardium is incised, and a large section is harvested for later use as a patch graft, which is essential for the baffle construction.
• Step 4: Cannulation and Cardiopulmonary Bypass - The aorta and superior and inferior vena cava are cannulated to establish cardiopulmonary bypass. This step is crucial as it allows the heart to be temporarily stopped while the surgical repair is performed.
• Step 5: Cross-Clamping the Aorta - The aorta is cross-clamped to control blood flow during the procedure, ensuring a bloodless field for the surgical repair.
• Step 6: Incising the Right Atrium - The right atrium is incised to access the atrial septum, which will be resected to facilitate the creation of the baffle.
• Step 7: Creating the Atrial Baffle - A patch made of synthetic material, autologous pericardium, or an allograft is used to redirect systemic venous blood from the superior and inferior vena cava to the orifice of the mitral valve, characteristic of the Mustard type procedure. Alternatively, flaps of native atrial septum and atrial wall may be used for the Senning type procedure.
• Step 8: Patching the Atrial Wall - The atrial wall is patched using the previously harvested section of pericardium to complete the baffle construction.
• Step 9: Removal of the Pulmonary Band - If applicable, the previously placed pulmonary band is dissected free and removed. This step is essential for patients who have had a pulmonary band placed prior to this procedure.
• Step 10: Assessing Pulmonary Artery Stenosis - The pulmonary artery stenosis is assessed using a transducer and probe, and dilation of the pulmonary artery is performed as needed to ensure adequate blood flow.
• Step 11: Closing the Procedure - Following the completion of the repair, the sternum may be closed or left open for subsequent procedures. Chest tubes are placed as needed to manage any postoperative fluid accumulation.

3. Post-Procedure

After the completion of the atrial baffle procedure with the removal of the pulmonary band, patients typically require close monitoring in a postoperative setting. The expected recovery may vary based on individual patient factors and the complexity of the procedure. Postoperative care includes managing any potential complications, monitoring cardiac function, and ensuring adequate respiratory support. Chest tubes, if placed, will be monitored for drainage, and patients will be assessed for signs of infection or other postoperative issues. Follow-up care will be necessary to evaluate the success of the procedure and to monitor for any long-term complications associated with transposition of the great arteries.