Summary & Overview
CPT 33641: Open Atrial Septal Defect Patch Closure
CPT code 33641 designates open surgical closure of an atrial septal defect (ASD) via atriotomy with patch repair under direct visualization. This operative code captures a definitive, invasive cardiac procedure used to correct intracardiac shunts that can lead to right-sided volume overload, arrhythmia, or heart failure if untreated. Nationally, accurate coding of such major cardiac surgeries matters for clinical registry tracking, hospital quality reporting, and payer adjudication of high-acuity services.
Key payers in the scope of typical coverage and reimbursement analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find clinical context about the procedure, typical sites of service, and the types of claims considerations linked to complex cardiac operations. The publication outlines benchmarks and payment-related themes relevant to inpatient surgical cardiovascular care, summarizes common modifiers supplied in the input, and highlights areas where billing clarity affects hospital revenue cycle and clinical documentation.
The report is intended for coding professionals, hospital finance leaders, and clinicians involved in perioperative documentation, providing concise guidance on the code's clinical meaning, payer relevance, and where to focus documentation for accurate claim submission. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 33641 describes a surgical closure of an atrial septal defect (ASD) by open atriotomy with patch closure under direct visualization. The procedure involves opening the atrium to access the septal defect and closing it with a patch while the surgeon visualizes the repair directly.
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Service type: Open cardiac surgical repair of congenital or acquired atrial septal defects
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Typical site of service: Hospital operating room, commonly performed in a cardiac surgery suite or tertiary care center
Clinical & Coding Specifications
Clinical Context
A 6-year-old child is referred to pediatric cardiothoracic surgery for symptomatic secundum atrial septal defect (ASD) with evidence of right atrial and right ventricular enlargement on echocardiogram and exertional intolerance. The patient undergoes preoperative evaluation including transthoracic echocardiography, chest X-ray, basic labs, and anesthesia assessment. In the operating room under general endotracheal anesthesia, the cardiothoracic surgeon performs median sternotomy, cardiopulmonary bypass, and atriotomy to directly visualize the ASD. The defect is closed with a synthetic or autologous patch and secured with sutures; the atrium is closed, the heart de-aired, and the patient weaned from bypass. Postoperatively, the patient is transferred to the pediatric cardiac intensive care unit for monitoring, pain control, hemodynamic support as needed, and follow-up echocardiography prior to discharge. Typical length of stay is 3–7 days depending on age and comorbidities. This procedure is performed in an inpatient hospital operating room setting by a cardiothoracic surgeon or pediatric cardiac surgeon and billed as an open surgical atrial septal defect repair under code 33641.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Undefined/Not otherwise specified standard modifier | Rarely used; not appropriate for most claims—use payer-specific guidance |