Migration of prosthetic aortic valve into abdominal aorta

A 51-year-old female presented to the emergency with acute onset shortness of breath and cough. There was no history of fever. She had history of rheumatic heart disease and underwent aortic and mitral valve replacement in 2020. The last echocardiography done one month ago showed appropriately placed prosthetic valves and suspected infective endocarditis in view of a mobile echogenic lesion (2.0x1.0 cm) stuck to the prosthetic aortic valve.

Non-contrast CT scan of the chest showed confluent-dependent consolidation and perihilar ground glass opacities with smooth septal thickening in both lungs along with bilateral mild pleural effusion, imaging features were consistent with pulmonary oedema.

Cardiomegaly was seen with appropriately placed prosthetic mitral valve. Prosthetic aortic valve was not seen in its expected location and it had migrated into abdominal aorta, lying at the level of coeliac artery origin.

Previous frontal chest radiograph done one month back was reviewed which showed normally positioned prosthetic mitral and aortic valves.

Prosthetic heart valves are the definitive surgical management of severe cardiac valvular heart disease [1]. There are mainly two types of prosthetic valves, mechanical and bioprosthetic valves. The mechanical valves have excellent longevity but with low thromboresistance, hence require lifelong anticoagulation therapy [2]. Mainly two designs of mechanical valves are available bileaflet and tilting disk, bileaflet design being the most common [3]. Bioprosthetic valves which are either composed of human (homografts) or animal tissue (xenografts) are less durable but have excellent thromboresistance hence alleviating the need of life long anticoagulation [4]

Complications associated with the prosthetic valves can be broadly classified into structural dysfunction, which are abnormalities intrinsic to the valve, and non-structural dysfunctions like dehiscence, pannus, vegetation and leaks [4]. Bioprosthetic valves are more prone to structural failures than the mechanical valves [5], with a failure rate of 10-20% in 10-15 years for homografts and 30% for heterografts [6]. The valve leaflets and stents are common sites of structural damage in bioprosthetic valves. Common causes of structural failure of the mechanical valves include separation of sewing cuff from its housing and fracture of strut with embolization of the disk [4]. The dysfunctional valve can migrate distally into aorta. These patients present with severe dyspnea and acute pulmonary oedema [7]. Structural failures are more common in patients less than 65 years old owing to reduced patient activity in the older age group that is greater than 65 years old [5].

Both the valves in our patient were mechanical prosthetic valves.

Written informed consent for publication has been obtained.