CPT® Code 33777

1. Indications

The procedure described by CPT® Code 33777 is indicated for patients diagnosed with transposition of the great arteries, particularly when this condition is complicated by subpulmonic obstruction. The following conditions may warrant the performance of this surgical intervention:

• Transposition of the Great Arteries - A congenital heart defect where the aorta arises from the right ventricle and the pulmonary arteries arise from the left ventricle, leading to improper circulation of oxygenated and deoxygenated blood.
• Subpulmonic Obstruction - A narrowing of the area below the pulmonary valve, which can impede blood flow from the right ventricle to the lungs, necessitating surgical intervention to alleviate the obstruction.
• Associated Cardiac Anomalies - Conditions such as ventricular septal defect (VSD) and other structural heart defects that may coexist with transposition of the great arteries and require correction during the same surgical procedure.

2. Procedure

The surgical procedure for CPT® Code 33777 involves several critical steps to effectively repair transposition of the great arteries and address subpulmonic obstruction. The following procedural steps are performed:

• Accessing the Heart - The procedure begins with the patient being placed under general anesthesia. A median sternotomy or thoracotomy is performed to gain access to the heart. This involves making an incision along the sternum or side of the chest to expose the thoracic cavity.
• Resecting the Thymus - The thymus gland is resected to provide better access to the heart structures and to facilitate the surgical procedure.
• Incising the Pericardium - The pericardium, which is the fibrous sac surrounding the heart, is incised, and a large section is harvested for later use as a patch graft in the atrial baffle construction.
• Establishing Cardiopulmonary Bypass - The aorta and superior and inferior vena cava are cannulated to establish cardiopulmonary bypass. This allows for the heart to be temporarily stopped while maintaining blood circulation and oxygenation through the bypass machine.
• Cross-Clamping the Aorta - The aorta is cross-clamped to control blood flow and facilitate the surgical repair of the heart structures.
• Incising the Right Atrium - An incision is made in the right atrium, and the atrial septum is resected to create a pathway for redirecting systemic venous blood.
• Constructing the Atrial Baffle - A patch made of synthetic material, autologous pericardium, or an allograft is used to redirect blood from the superior and inferior vena cava to the orifice of the mitral valve (Mustard type procedure). Alternatively, flaps of native atrial septum and atrial wall may be used to construct the baffles (Senning type procedure).
• Patching the Atrial Wall - The atrial wall is patched using the previously harvested section of pericardium to complete the baffle construction.
• Removing Obstructive Tissue - The obstructive tissue located below the pulmonary valve is carefully removed to alleviate the subpulmonic obstruction.
• Closing the Sternum - After the repair is completed, the sternum may be closed or left open for subsequent closure, depending on the clinical situation. Chest tubes are placed as needed to manage post-operative drainage.

3. Post-Procedure

Post-procedure care following the atrial baffle procedure with repair of subpulmonic obstruction includes monitoring the patient in a critical care setting to assess for any complications. Patients may require close observation for signs of bleeding, infection, or cardiac complications. Pain management is provided, and chest tubes are monitored for drainage. The recovery process may vary based on the individual patient's condition and the extent of the surgical intervention. Follow-up imaging studies may be necessary to evaluate the success of the repair and the function of the heart structures. The surgical team will provide specific instructions regarding activity restrictions and follow-up appointments to ensure optimal recovery.