Summary & Overview
CPT 33770: Arterial Switch with Pulmonary Infundibular Resection
CPT code 33770 identifies a specialized congenital cardiac operation—an arterial switch with resection of an obstructive pulmonary infundibular muscle—used to correct ventriculo-arterial discordance where the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. This complex surgical repair restores normal circulation and relieves obstruction without enlarging a ventricular septal defect. Nationally, this code represents high-acuity, resource-intensive pediatric cardiothoracic care performed predominantly in inpatient surgical settings and tertiary pediatric centers.
Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical and billing orientation to the procedure, an explanation of typical service context and site of care, and identification of common modifiers used with the code. The summary highlights what stakeholders need to know about clinical intent, common billing considerations, and where to look for additional payer-specific policy details. This information is aimed at hospital coding teams, revenue cycle managers, and clinicians seeking a clear, national-level description of the service associated with CPT code 33770 and the billing context surrounding complex congenital heart surgery.
Billing Code Overview
CPT code 33770 describes a corrective cardiac surgical procedure for a congenital malformation in which the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. The operation restores normal ventricular–arterial connections by switching the aorta and pulmonary artery to their correct anatomic positions without enlarging a ventricular septal defect. The procedure also includes removal of an obstructive fibrous muscular band at the tip of the pulmonary artery.
Service type: Congenital cardiac corrective surgery (arterial switch with pulmonary infundibular muscle resection)
Typical site of service: Inpatient hospital, operating room (cardiothoracic surgery)
Clinical & Coding Specifications
Clinical Context
A typical patient is an infant or young child diagnosed with d-transposition of the great arteries (d-TGA) who presents with cyanosis and differential oxygen saturation shortly after birth. Initial stabilization occurs in the neonatal intensive care unit with supplemental oxygen, prostaglandin E1 as indicated to maintain ductal patency, and possible balloon atrial septostomy if inadequate interatrial mixing exists. After diagnostic confirmation with transthoracic echocardiography and assessment by pediatric cardiology and cardiothoracic surgery, the patient is scheduled for corrective open-heart surgery — an arterial switch operation without ventricular septal defect enlargement and with resection of an obstructive pulmonary artery (infundibular) muscular band.
The clinical workflow includes preoperative evaluation (anesthesia assessment, crossmatch, imaging review), operative repair via median sternotomy on cardiopulmonary bypass with coronary artery reimplantation and LeCompte maneuver as indicated, removal of the obstructive muscle bundle at the pulmonary outflow tract, intraoperative transesophageal or epicardial echocardiography to confirm repair, and postoperative care in the pediatric cardiac intensive care unit with ventilatory and hemodynamic support, analgesia, infection prophylaxis, and staged follow-up imaging and clinic visits.
Typical site of service: Pediatric tertiary care hospital or specialized cardiac surgery center with cardiothoracic operating suite and pediatric cardiac intensive care unit.
Service type: Major open cardiac surgical procedure (corrective congenital heart surgery).
Coding Specifications
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