Summary & Overview
CPT 33645: Sinus Venosus Atrial Septal Defect Closure
CPT code 33645 denotes surgical closure of a sinus venosus atrial septal defect, either by direct suture or patch, and may be performed in patients with or without anomalous pulmonary venous drainage. This code captures a specialized cardiothoracic procedure used to correct a congenital interatrial communication that can have significant clinical consequences if left untreated. Nationally, accurate coding for this repair supports clinical quality measurement, appropriate reimbursement for complex cardiac surgery, and tracking of congenital heart defect interventions across hospital systems.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context and procedural scope, payer coverage considerations, and typical billing elements associated with this inpatient surgical service. The publication provides benchmarks and policy-relevant summaries where available, highlights common billing modifiers and payer interactions provided in the input, and outlines areas where additional documentation or coding specificity may affect claims processing. Data not available in the input is identified for items such as associated taxonomies, specific ICD-10 diagnoses, and related codes.
Billing Code Overview
CPT code 33645 describes the surgical closure of a sinus venosus atrial septal defect, performed either directly or with a patch. The procedure may be done in patients with or without anomalous pulmonary venous drainage.
Service type: Cardiac congenital heart defect repair (open surgical repair of atrial septal defect variant)
Typical site of service: Inpatient hospital operating room or cardiac surgery suite, often performed by cardiothoracic surgery teams with cardiopulmonary bypass support when indicated.
Clinical & Coding Specifications
Clinical Context
A typical patient is a young adult or child diagnosed with a sinus venosus atrial septal defect (ASD), often identified after evaluation for exertional dyspnea, recurrent respiratory infections, or paradoxical embolic events. Preoperative workup includes transthoracic and transesophageal echocardiography to define the defect and detect any anomalous pulmonary venous drainage, cardiac catheterization if pulmonary vascular resistance assessment is needed, and routine preoperative labs and crossmatch. The surgical workflow for 33645 begins with general anesthesia and median sternotomy or minimally invasive approach. Cardiopulmonary bypass is established, the right atrium is opened, and the sinus venosus defect is directly closed or patched; anomalous pulmonary veins, if present, are rerouted or repaired during the same operative session. Intraoperative transesophageal echocardiography confirms closure and hemodynamics prior to weaning from bypass. Postoperative care includes intensive monitoring in a pediatric or adult cardiac ICU, analgesia, anticoagulation management when indicated, follow-up echocardiography, and discharge planning with cardiology follow-up for long-term surveillance of residual shunts or arrhythmias. Typical sites of service are an inpatient hospital operating room and tertiary pediatric or adult cardiac surgery centers. The service type is open cardiac surgical repair of a congenital atrial septal defect (sinus venosus), with or without repair of anomalous pulmonary venous connection.
Coding Specifications
| Modifier | Description | When to Use |
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