CPT® Code 33774

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

The procedure described by CPT® Code 33774 involves the surgical repair of transposition of the great arteries (TGA) using an atrial baffle technique, which is commonly known as 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 TGA, 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 often coexists with other cardiac anomalies, such as ventricular septal defect (VSD) and subpulmonary stenosis. VSD is a defect characterized by an abnormal opening in the ventricular septum, allowing 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 complicate the surgical approach and necessitate a tailored operative plan for each patient. The surgical intervention typically requires access to the heart through a median sternotomy or thoracotomy, during which the thymus gland may be resected. The pericardium is incised, and a section is harvested for use as a patch graft. The procedure involves cannulating the aorta and the superior and inferior vena cava to establish cardiopulmonary bypass, followed by cross-clamping the aorta. The right atrium is then incised, and the atrial septum is resected to facilitate the creation of an atrial baffle. This baffle is constructed using either a patch of synthetic material, autologous pericardium, or an allograft to redirect systemic venous blood to the mitral valve orifice, effectively separating the pulmonary venous blood flow. Alternatively, the Senning procedure may utilize flaps of the native atrial septum and wall to create the baffle. The previously harvested pericardial patch is then used to close the atrial wall. This procedure is critical for correcting the hemodynamic abnormalities associated with transposition of the great arteries and improving the patient's overall oxygenation and circulation.