CPT® Code 33670

1. Indications

The procedure described by CPT® Code 33670 is indicated for patients diagnosed with a complete atrioventricular canal (AVC), which is a congenital heart defect. The following conditions may warrant this surgical intervention:

• Complete Atrioventricular Canal Defect This condition involves defects in all central heart structures, including holes in both the atrial and ventricular septa, along with an undivided or common atrioventricular valve.
• Heart Failure Symptoms Patients may present with symptoms of heart failure due to the mixing of oxygenated and deoxygenated blood, necessitating surgical repair to improve cardiac function.
• Increased Pulmonary Blood Flow The presence of significant left-to-right shunting can lead to increased pulmonary blood flow, which may require surgical correction to prevent pulmonary hypertension and other complications.

2. Procedure

The surgical procedure for CPT® Code 33670 involves several critical steps to repair the complete atrioventricular canal:

• Step 1: Accessing the Heart The surgeon begins by performing a median sternotomy, which provides access to the thoracic cavity and the heart. This approach allows for optimal visualization and manipulation of the heart structures.
• Step 2: Establishing Cardiopulmonary Bypass Bicaval and aortic cannulas are inserted to establish cardiopulmonary bypass. This technique temporarily takes over the function of the heart and lungs, allowing the surgeon to operate on a still heart.
• Step 3: Incising the Pericardium The pericardium is incised to expose the heart, and a patch is harvested for the repair of the septal defects.
• Step 4: Atriotomy An incision is made in the right atrium (atriotomy) to expose the atrioventricular septal defect. This step is crucial for accessing the defects that need repair.
• Step 5: Inspecting the Valves The tricuspid and mitral valves are inspected for size and competence. This evaluation is essential to determine the necessary repairs to ensure proper valve function.
• Step 6: Repairing the Mitral Valve The cleft in the mitral valve is repaired first through the septal defect. Additional tailoring of the mitral valve is performed as needed to ensure its competence and prevent stenosis.
• Step 7: Repairing the Tricuspid Valve Any defects in the tricuspid valve are also repaired to restore normal function.
• Step 8: Closing the Atrial Septal Defect The atrial septal defect (ASD) is then closed using a patch of pericardium or sutures, depending on the size of the defect.
• Step 9: Closing the Ventricular Septal Defect The small ventricular septal defect (VSD) is closed with sutures, and the cleft in the atrioventricular valve is repaired to form two separate valves.
• Step 10: Evaluating the Common Atrioventricular Valve The common atrioventricular valve is elevated, and its competence and structure are evaluated. If separation of the common valve is possible, it is performed; otherwise, one or both valves may be replaced with a prosthetic valve.
• Step 11: Finalizing the Repair Following the repair of the valves, the ASD is closed with a pericardial patch. The right atrial incision is then closed, and the patient is weaned off cardiopulmonary bypass.
• Step 12: Closing the Chest Incision Chest tubes are placed as needed to drain any excess fluid, and the chest incision is closed to complete the procedure.

3. Post-Procedure

After the completion of the procedure, the patient will undergo monitoring in a recovery area to assess cardiac function and overall stability. Post-operative care may include the management of pain, monitoring for any signs of complications such as bleeding or infection, and ensuring proper respiratory function. The placement of chest tubes may be necessary to facilitate drainage of any fluid accumulation. The recovery period will vary based on the individual patient's condition and response to surgery, but close follow-up is essential to evaluate the success of the repair and the function of the heart valves. Regular follow-up appointments will be scheduled to monitor the patient's progress and address any ongoing concerns.