A paravalvular leak, paravalvular leakage or paravalvular regurgitation are an abnormal flow between the valvular annulus and the prosthetic heart valve and is a common complication after valvular replacement surgery due to inadequate sealing.

Epidemiology

Paravaluvar leaks are common, with an estimated prevalence of 2-10% after aortic valve replacement and about 7-17% after mitral valve replacement ^1-3.

Risk factors

Factors increasing the likelihood for paravalvular leaks include the following ³:

• annular calcification

• tissue friability

• prior infective endocarditis

• recent initiation of corticosteroid therapy

• valve type: mechanical valve > bioprosthetic implant

• valve position: supra-annular aortic valve > annular prosthesis

• technique: continuous suture > interrupted suture

Clinical presentation

Paravalvalvular leaks might present a complication, e.g. heart failure or haemolytic anaemia or might be discovered on post-procedural imaging ².

Complications

Complications of a paravalvular leak include the following conditions ^1,2:

• heart failure

• haemolytic anaemia

• infective endocarditis

• stroke

Pathology

Aetiology

Causes of a paravalvular leak include the following ^1,3:

• valvular dehiscence

• infective endocarditis

• resorption of annular calcification

• incorrect suturing of the valve to the annulus

Location

The most common site of aortic paravalvular leaks is around the non-coronary leaflet. In contrast, paravalvular leaks of the mitral valve are more commonly located in an anterolateral or a posteromedial position ^3,4.

Radiographic features

Ultrasound

Echocardiography

Echocardiography is considered the reference standard and first-line imaging modality for the assessment and can identify a paravalvular leak as a hypoechoic area, often with a crescentic or serpentine shape and flow on colour Doppler outside the sewing ring of the prosthesis ¹.

CT

Cardiac CT shows a contrast-filled channel outside the valve in the paravalvular region connecting the proximal and distal luminal area of the valve ^1,4.

MRI

Cardiac MRI can show a separation of the sewing ring of the prosthetic valve and depict a paravalvular leak with dark dephasing artifacts in cine imaging and assess the orifice area ¹.

Moreover, regurgitation can be quantified by phase-contrast MRI ^1,3.

Radiology report

The radiological report should include a description of the following features ^2,4:

• size and location in relation to anatomical landmarks

• shape and course

• regurgitant orifice

• annular calcifications

• regurgitant volume

Treatment and prognosis

Management of paravalvular leaks includes surgical repair and transcatheter approach for closure with a vascular plug or occluder ^1-4.

Differential diagnosis

Conditions that can mimic the imaging appearance of a paravalvular leak include the following ¹:

• paravalvular abscess

• pseudoaneurysm

• surgical pledget material