Complementary role of cardiac CT in the assessment of aortic valve replacement dysfunction

Abstract

Aortic valve replacement is the second most common cardiothoracic procedure in the UK. With an ageing population, there are an increasing number of patients with prosthetic valves that require follow-up. Imaging of prosthetic valves is challenging with conventional echocardiographic techniques making early detection of valve dysfunction or complications difficult. CT has recently emerged as a complementary approach offering excellent spatial resolution and the ability to identify a range of aortic valve replacement complications including structural valve dysfunction, thrombus development, pannus formation and prosthetic valve infective endocarditis. This review discusses each and how CT might be incorporated into a multimodal cardiovascular imaging pathway for the assessment of aortic valve replacements and in guiding clinical management.

Figure 1

Structural valve degeneration. (A and B) Bioprosthetic aortic valves calcify along the cusp commissures mimicking the pattern found in native aortic valve disease. (C) Calcified leaflets are reflected onto the sinus walls during transcatheter valve implantation.

Figure 2

(A and B) Hypoattenuation leaflet thickening suggestive of thrombus formation on the supravalvular surface impinging leaflet motion. (C and D) Pannus formation underneath the prosthesis can also restrict leaflet motion necessitating surgical removal of the prosthesis.

Figure 3

Prosthetic valve infective endocarditis. (A) Complications of prosthetic valve infective endocarditis include the development of perivalvular pseudoaneurysm formation (white asterix). (B) Saccular pseudoaneurysms (white asterix) occur in regions where vegetations (white arrow) erode through the annulus with a loss of sewing ring integrity. (C) Bacterial spread into the aortic root results in abscess formation (white asterix). (D) The anatomical location of erosive shunts (white arrow) and paravalvular leaks due to suture dehiscence can be readily identified using cardiac CT. LA, left atrium; RA, right atrium.

Figure 4

Suggested pathway for assessment of aortic valve replacement dysfunction. Transthoracic echocardiography with follow-on transoesophageal echocardiography and cardiac CT provides a detailed functional and anatomical assessment to guide further management. AVR, aortic valve replacement, ViV TAVI, valve-in-valve transcatheter aortic valve implantation.

Figure 5

An example adjunctive CT imaging in the management of aortic valve replacement dysfunction. (A) Severe prosthesis regurgitation on transoesophageal echocardiography resulted from calcific structural valve dysfunction of the bioprosthetic leaflets in a 27 mm Aspire bioprosthesis demonstrated on CT (B). (C and D) Preprocedural planning facilitated implantation of a transcatheter aortic valve in valve.