Medical Necessity of CPT 33863 and Inpatient Care for Bicuspid Aortic Valve with Aortic Root Aneurysm
Yes, CPT code 33863 (ascending aortic graft with cardiopulmonary bypass, with aortic root replacement using valved conduit and coronary reconstruction) and inpatient level of care are medically necessary for a patient with bicuspid aortic valve and aortic root aneurysm undergoing aortic root aneurysm repair.
Surgical Indication Based on Bicuspid Aortic Valve
Patients with bicuspid aortic valve and aortic root aneurysm meet Class I surgical indications at lower diameter thresholds than those with tricuspid valves. The 2022 ACC/AHA guidelines establish that surgical intervention is reasonable at ≥5.0 cm for bicuspid aortic valve patients when performed by experienced surgeons in a Multidisciplinary Aortic Team 1. The 2010 ACC/AHA guidelines further specify that patients with bicuspid aortic valves should undergo elective operation at smaller diameters (4.0 to 5.0 cm depending on the condition) to avoid acute dissection 1.
For patients undergoing aortic valve repair or replacement who have an ascending aorta or aortic root greater than 4.5 cm, concomitant repair of the aortic root or replacement of the ascending aorta should be considered (Class I recommendation) 1. The European Society of Cardiology guidelines support lower thresholds for concomitant aortic replacement (<45 mm) depending on age, body surface area, etiology of valvular disease, and presence of a bicuspid aortic valve 1.
Appropriateness of CPT 33863 Procedure
CPT code 33863 represents ascending aortic graft with cardiopulmonary bypass, including aortic root replacement using a valved conduit (composite valve graft/Bentall procedure) and coronary reconstruction. This procedure is specifically indicated for patients with dilated aortic root, particularly those with stenotic bicuspid valves, where composite valve grafts containing either mechanical or biological valves are implanted 1.
The guidelines establish that composite valve grafts are an appropriate option, particularly for valvular stenosis, when valve-sparing procedures are not feasible 1. For patients with aortic regurgitation associated with a bicuspid aortic valve, repair with root remodeling is preferable if the valve is not severely fibrotic or calcified; however, when the valve is severely diseased, composite graft replacement is the standard approach 1.
Research evidence supports excellent outcomes with this approach. A 30-year experience with aortic root replacement demonstrated in-hospital mortality of 4.0% for composite valve conduit procedures, with actuarial survival of 93% at 5 years and 79% at 10 years 2. Freedom from reoperation was 72% at 20 years, with few serious complications related to anticoagulation or prosthetic valve 2.
Medical Necessity of Inpatient Level of Care
Aortic root replacement with composite valve graft is a major open-heart surgery requiring cardiopulmonary bypass, hypothermic circulatory arrest techniques, and coronary artery reimplantation, making inpatient hospitalization absolutely mandatory. The procedure involves:
- Cardiopulmonary bypass with aortic cross-clamping 1
- Complete aortic root excision and replacement with prosthetic graft 1
- Coronary artery reimplantation into the graft 1
- Mechanical or biological valve implantation 1
- Potential ancillary procedures including coronary artery bypass grafting, repair of cardiac septal defects, or ablative therapy for arrhythmias 1
The complexity and invasiveness of this procedure necessitate intensive postoperative monitoring for complications including bleeding (requiring reoperation in 4% of cases), stroke (1%), perioperative myocardial infarction (5%), and hemodynamic instability 2. There is no scenario in which this procedure could be performed in an outpatient or observation setting.
Additional Considerations for Bicuspid Aortic Valve Patients
Patients with bicuspid aortic valve have specific risk factors that support earlier intervention. The 2022 ACC/AHA guidelines note that rapid aortic growth (≥0.3 cm in 1 year for those with bicuspid aortic valve) is an indication for intervention 1. Additionally, surgical thresholds may be adjusted based on patient genetics, cross-sectional aortic area/height ratio ≥10 cm²/m, aortic size index of ≥3.08 cm/m², or aortic height index of ≥3.21 cm/m 1.
Common pitfall to avoid: Do not delay surgery in bicuspid aortic valve patients until they reach the 5.5 cm threshold used for tricuspid valves, as these patients are at higher risk for dissection at smaller diameters 1, 3.
Post-Operative Requirements
Following composite valve graft replacement, lifelong vitamin K antagonist anticoagulation is required for all patients receiving a mechanical heart valve prosthesis 4. Early CT imaging within 1 month after open repair is recommended, followed by yearly CT for 2 years, then every 5 years if findings remain stable 5, 4. Continued surveillance of the entire aorta is essential, as patients remain at risk for aneurysm formation and dissection in other segments 5, 6.