CPT® Code 33781

1. Indications

The procedure described by CPT® Code 33781 is indicated for patients diagnosed with transposition of the great arteries, particularly when associated with subpulmonic obstruction. The following conditions may warrant this surgical intervention:

• Transposition of the Great Arteries - A congenital heart defect where the aorta and pulmonary arteries are incorrectly positioned, leading to inadequate oxygenation of blood.
• Subpulmonic Obstruction - A narrowing below the pulmonary valve that can impede blood flow from the right ventricle to the lungs, necessitating surgical repair.
• Associated Cardiac Anomalies - Conditions such as ventricular septal defect (VSD) and subpulmonary stenosis that may complicate the transposition and require correction during the same surgical procedure.

2. Procedure

The surgical procedure for CPT® Code 33781 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 surgeon typically begins by performing a median sternotomy or thoracotomy to gain access to the heart. This may involve resecting the thymus gland to facilitate the procedure.
• Incising the Pericardium - The pericardium is incised, and a section is harvested for later use as a patch graft, which is essential for the reconstruction phase of the surgery.
• Dissection of Major Vessels - The ascending aorta, main pulmonary artery, and their branches are carefully dissected free from surrounding tissues to prepare for the reconstruction of the outflow tracts.
• Establishing Cardiopulmonary Bypass - The aorta and superior and inferior vena cava are cannulated, and cardiopulmonary bypass is established. The aorta is then cross-clamped to facilitate the surgical repair.
• Transecting the Aorta and Pulmonary Artery - The ascending aorta and main pulmonary artery are transected to allow for the visualization and excision of the coronary artery ostia at the anomalous aortic root.
• Transferring Coronary Artery Ostia - The ostia of the left and right coronary arteries are excised along with the adjacent aortic wall and are then transferred as buttons to the anomalous main pulmonary artery root sinuses in the left ventricle.
• Reconstructing the Outflow Tracts - The distal main pulmonary artery and its branches are brought forward to the right ventricle, while the aorta is repositioned posteriorly to the left ventricle.
• Anastomosing the Aorta - The distal aorta is anastomosed to the newly created aortic root in the left ventricle, ensuring proper blood flow is restored.
• Anastomosing the Coronary Arteries - The coronary arteries are also anastomosed to the newly created aortic outflow tract, completing the reconstruction of the arterial connections.

3. Post-Procedure

Following the completion of the surgical repair, the sternum may be closed or left open, with plans for closure in a subsequent procedure if necessary. Chest tubes are placed as needed to facilitate drainage and prevent fluid accumulation in the thoracic cavity. Post-operative care includes monitoring for complications, assessing the patient's recovery, and ensuring that the heart is functioning properly after the reconstruction. The patient may require additional interventions or therapies based on their overall condition and any associated anomalies that were addressed during the surgery.