33641

Repair of Atrial Septal Defect, Secundum, with Patch and/or Reconstruction

CPT code 33641 describes the surgical repair of a secundum-type atrial septal defect (ASD) using a patch and/or reconstruction techniques. A secundum ASD is a congenital cardiac anomaly characterized by a deficiency in the septum primum, resulting in an opening in the central portion of the atrial septum. This defect allows oxygenated blood to shunt from the high-pressure left atrium to the lower-pressure right atrium, leading to right ventricular volume overload and potential pulmonary hypertension over time. The procedure is typically performed under general anesthesia with the patient in a supine position. Access to the heart is usually achieved via a median sternotomy, although minimally invasive approaches like a right mini-thoracotomy may be utilized in specific cases. Once the chest is opened, the patient is placed on cardiopulmonary bypass (CPB) via cannulation of the ascending aorta and both the superior and inferior venae cavae. The heart is then arrested or kept beating depending on surgeon preference, often using cold cardioplegia for myocardial protection. The right atrium is opened (atriotomy) to expose the interatrial septum. The surgeon identifies the secundum defect and assesses its size and proximity to the pulmonary veins and the conduction system. In the context of code 33641, the defect is closed using a patch, which may be harvested from the patient's own pericardium (autologous) or consist of synthetic material such as Dacron or polytetrafluoroethylene (PTFE). The patch is meticulously sutured to the edges of the defect using a continuous or interrupted suture technique to ensure a secure, leak-proof seal. Following the closure, the right atriotomy is sutured, the heart is de-aired, the patient is weaned from CPB, and the chest is closed in layers with appropriate drainage tubes.

Clinical Indications

  • Hemodynamically significant secundum atrial septal defect
  • Right-sided cardiac chamber enlargement noted on echocardiography
  • Pulmonary-to-systemic flow ratio (Qp:Qs) greater than 1.5:1
  • History of paradoxical embolism associated with an ASD
  • Prevention of progressive pulmonary hypertension
  • Exercise intolerance or exertional dyspnea related to intracardiac shunting
  • Recurrent respiratory infections in pediatric patients with ASD

Procedure Steps

  1. Anesthetize the patient and perform a median sternotomy or right mini-thoracotomy.
  2. Harvest autologous pericardium if it is to be used for the patch repair.
  3. Establish cardiopulmonary bypass (CPB) via aortic and bicaval cannulation.
  4. Apply a cross-clamp to the aorta and administer cardioplegia to achieve cardiac arrest.
  5. Perform a longitudinal or transverse right atriotomy to expose the atrial septum.
  6. Identify and inspect the secundum atrial septal defect and surrounding structures.
  7. Tailor a patch (pericardial or synthetic) to the size and shape of the defect.
  8. Suture the patch to the rim of the defect using continuous non-absorbable sutures.
  9. Inspect the repair for residual leaks and ensure pulmonary venous drainage is unobstructed.
  10. Close the right atriotomy and initiate de-airing maneuvers of the cardiac chambers.
  11. Remove the aortic cross-clamp and allow the heart to resume normal rhythm.
  12. Wean the patient from cardiopulmonary bypass and remove cannulae.
  13. Perform a transesophageal echocardiogram (TEE) to confirm closure and valvular function.
  14. Secure hemostasis, place chest tubes, and close the sternotomy or thoracotomy incision.

Coding Guidelines

  • CPT 33641 includes the use of cardiopulmonary bypass (CPB); do not report 33641 with CPB codes separately.
  • If the ASD is closed via primary suture without a patch, use code 33640 instead.
  • Do not report 33641 in conjunction with repair of anomalous pulmonary venous return (e.g., 33724 or 33726) unless the ASD repair is a distinct, non-integral component.
  • For repair of a sinus venosus defect, use code 33645.
  • For repair of an ostium primum defect (atrioventricular canal defect), see codes 33647 or 33670.
  • Use modifier 62 if two surgeons (e.g., a pediatric cardiac surgeon and a general cardiac surgeon) act as co-surgeons.
  • Intraoperative transesophageal echocardiography (TEE) for monitoring may be reported separately (e.g., 93312-93318) if performed by a separate provider such as an anesthesiologist.

Associated ICD-10 Codes