What is the recommended surveillance schedule for a patient with a prosthetic (artificial) aortic valve and a thoracic aortic inner position graft, who has a stable fusiform aneurysmal dilation of the distal ascending thoracic aorta, with no concerning findings on the most recent gated computed tomography (CT) scan?

Surveillance Schedule for Prosthetic Aortic Valve with Ascending Thoracic Aortic Graft and Stable Fusiform Aneurysmal Dilation

For a patient with a prosthetic aortic valve, thoracic aortic graft, and stable fusiform aneurysmal dilation of the distal ascending aorta, annual surveillance imaging with CT or MRI is recommended, with the specific interval determined by the current aortic diameter. 1, 2

Imaging Modality Selection

• CT angiography (CTA) or MRI is mandatory for surveillance of distal ascending aortic aneurysms—transthoracic echocardiography is explicitly not recommended for monitoring aneurysms in this location. 1, 3

• CMR is preferred over CCT for long-term follow-up to minimize cumulative radiation exposure, particularly relevant given the need for serial imaging. 1, 4

• All follow-up imaging should be performed using the same imaging technique and at the same center to ensure measurement consistency and avoid artifactual changes. 1, 4

Surveillance Intervals Based on Current Diameter

The specific follow-up schedule depends on the current diameter of the aneurysmal segment:

• 40-44 mm diameter: Reimaging in 12 months, then annually if stable 2, 4

• 45-49 mm diameter: Annual imaging 1, 2, 4

• 50-54 mm diameter: Imaging every 6 months until surgical threshold is reached 1, 2, 4

• ≥55 mm diameter: Surgical intervention should be considered 1, 2, 4

Growth Rate Considerations

• If rapid expansion occurs (≥3 mm per year), increase surveillance frequency to every 6 months and consider earlier surgical intervention. 1, 2, 4

• If the aorta demonstrates stability over multiple years with no expansion, surveillance intervals may be lengthened beyond annual imaging, particularly for non-genetic aneurysms. 1

• After initial diagnosis confirmation, reimaging at 6-12 months is recommended to establish the growth rate before settling into a routine surveillance schedule. 1, 2

Post-Surgical Surveillance

Given the patient has a prosthetic valve and graft:

• Early post-operative imaging should have been performed within 1 month of surgery, then yearly for the first 2 years. 2, 4

• If findings have been stable for 2 years post-operatively, surveillance can be extended to every 5 years for the grafted segments. 2, 4

• However, the non-grafted aneurysmal segment requires continued surveillance according to the diameter-based intervals outlined above, as this represents ongoing pathology. 1, 2

Critical Pitfalls to Avoid

• Do not use echocardiography alone for surveillance of distal ascending aortic aneurysms—it lacks the precision needed for this location and may miss critical changes. 1

• Ensure measurements are obtained using the double oblique method with multiplanar reconstructions to account for the oblique course and tortuosity of the ascending aorta. 3

• Patient compliance with surveillance is essential—non-compliance is associated with significantly higher rupture rates. 2, 4

• If there is any discrepancy ≥3 mm between imaging modalities, all subsequent surveillance must be performed with CT or MRI, not echocardiography. 2, 3

Concurrent Medical Management

• Optimal cardiovascular risk factor management is mandatory to reduce major adverse cardiovascular events, including aggressive blood pressure control. 1, 4

• Avoid fluoroquinolone antibiotics unless absolutely necessary, as they are associated with increased aortic complications. 4