CPT® Code 33777

Repair of transposition of the great arteries, atrial baffle procedure (eg, Mustard or Senning type) with cardiopulmonary bypass; with repair of subpulmonic obstruction

The procedure described by CPT® Code 33777 involves the surgical repair of transposition of the great arteries using an atrial baffle technique, which can be categorized as either the Mustard or Senning procedure. Transposition of the great arteries is a congenital heart defect characterized by the abnormal positioning of the aorta and pulmonary arteries. In a normal heart, the aorta arises from the left ventricle, while the pulmonary arteries originate from the right ventricle. However, in this condition, the aorta is connected to the right ventricle, and the pulmonary arteries are connected to the left ventricle. This anatomical arrangement results in a situation where oxygen-poor blood is circulated back to the body without passing through the lungs for oxygenation, while oxygen-rich blood returns to the lungs instead of being delivered to the body. This condition is often associated with other cardiac anomalies, such as ventricular septal defect (VSD) and subpulmonary stenosis. VSD is characterized by an abnormal opening in the ventricular septum, allowing for the mixing of oxygen-rich and oxygen-poor blood. Subpulmonary stenosis refers to a narrowing of the main pulmonary artery just below the pulmonary valve, which can further complicate the condition. The surgical approach to repair transposition of the great arteries, particularly when complicated by subpulmonary stenosis, requires careful planning and may differ significantly from one patient to another. Access to the heart is typically achieved through a median sternotomy or thoracotomy, and the procedure involves resection of the thymus and incision of the pericardium to harvest a patch graft. Cardiopulmonary bypass is established, and the aorta is cross-clamped to facilitate the repair. The right atrium is incised, and the atrial septum is resected to create a pathway for redirecting systemic venous blood to the mitral valve orifice. The atrial baffle is constructed using either synthetic material, autologous pericardium, or native atrial tissue, depending on the specific technique employed. The procedure also includes the removal of obstructive tissue below the pulmonary valve, which is essential for addressing the subpulmonic obstruction. Following the repair, the sternum may be closed or left open for subsequent closure, and chest tubes are placed as necessary to manage post-operative drainage.