Paravalvular leak (PVL) is an uncommon but potentially serious complication after prosthetic valve implantation. PVLs consist of an abnormal communication between two cardiac chambers adjacent to a prosthetic valve and manifest as a regurgitant jet originating between the outer margin of the prosthetic valve and the native tissue surrounding it. They may be due to abnormal pressure or traction forces on the prosthesis after surgery, and several factors are known to increase the risk of PVL, including annular calcification, infection, suturing technique, size and shape of the prosthetic implant and tissue friability. Early PVL is usually related to technical aspects of the surgical implant, whereas late PVL commonly results from suture dehiscence caused by endocarditis or the gradual resorption of incompletely debrided annular calcifications.1,2

The incidence of PVL is estimated to be 2-10% after surgical aortic valve replacement and 7-17% after mitral valve replacement. Most PVLs are asymptomatic, but in 1-5% of cases they have severe clinical consequences, with symptoms of congestive heart failure (CHF), hemolysis, or both.1,3

Until recently, surgery was the standard treatment, despite the high morbidity and mortality associated with reoperation. Alternatives to surgical closure of PVLs have been pursued over the years and in 1992 the first report on percutaneous PVL closure was presented, proving that the principles of percutaneous techniques to close intracardiac shunts could be translated to percutaneous PVL closure.1,2,4 Since then, percutaneous approaches to PVL closure have been developed as a less invasive strategy, through transseptal, apical left ventricular or retrograde arterial access, and a number of series have been published, with high rates of procedural success and favorable clinical outcomes.5

This study reports our experience with this technique, aiming to review the efficacy and safety of percutaneous device closure in a consecutive series of patients with clinically significant PVL referred to our center.

There were 20 procedures in 18 patients with leaks in biological valve prostheses (50.0%) and in mechanical valve prostheses (50.0%) (Video 1). Two patients underwent two procedures, both of which failed due to inability to cross the leak with the guidewire. One had a PVL in a mechanical mitral valve, while the other had two PVLs in a mitral bioprosthesis in septal position, one successfully closed with an Amplatzer® Duct Occluder device and another with an Amplatzer™ Vascular Plug device five months later. This was the only patient to receive two devices. Most of the PVLs closed were in mitral bioprostheses (Figure 2). There were 14 mitral PVLs treated in 13 patients (Video 2) and one aortic PVL treated in one patient.

Figure 2.

Study group profile. Eighteen patients were referred for percutaneous PVL closure at our center. Sixteen patients underwent a single procedure and two a second procedure, in a total of 20 procedures. Fifteen procedures were successful: 14 PVL closures in mitral prostheses (eight in biological and six in mechanical mitral valves) and one in a biological aortic prosthesis. PVL: paravalvular leak.

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Technical success was achieved in 75% (15) of the procedures. PVL closure failed in five interventions: two cases due to inability to cross the leak with the guidewire and three cases due to interference with the mechanical function of the prosthetic valve. The Amplatzer™ Vascular Plug III was used in nine (50.0%) patients and the Amplatzer™ Duct Occluder in two (11.2%). The Amplatzer™ Vascular Plug II, Amplatzer™ Muscular VSD Occluder and Amplatzer™ PDA closure device were used in one patient (5.6%) each. No device was implanted in four patients (22.2%). Median fluoroscopy time was 40.8 min for all procedures, 43.5 min (range 16.8-92.6) for mitral PVL closure and 28.4 min for aortic PVL closure. Table 2 shows the results of the interventions.

Small PVLs can be found on echocardiography in almost half of patients with prosthetic heart valves. In up to 5% of these patients, a larger leak with clinical significance may be apparent, most often associated with mitral valves, less often with aortic and rarely with tricuspid or pulmonary valves. Whether bioprostheses are associated with a greater risk of PVL than mechanical valves is still a matter of debate.8

Clinical presentation may occur soon after surgery or years later, as documented by our experience. Symptoms may be due to the degree of regurgitation, leading to low effective cardiac output, CHF and/or hemolytic anemia, which arises from fragmentation of red blood cells in the high shear stress of the regurgitant jet. Primary or secondary infective endocarditis can also occur.8

Spontaneous closure of PVLs is rare and medical treatment is largely palliative. Surgical correction has been the gold standard for treatment of PVL but is usually reserved for severely symptomatic patients and/or those with progressive cardiac dysfunction. The surgical mortality rate can be as high as 13% after the first procedure, in part due to the age and comorbidities of these patients, and in many symptomatic patients reoperation carries excessive risk and is usually not an option.3,8

Our experience demonstrates that percutaneous PVL closure can be a feasible treatment alternative in patients who are not candidates for surgery. As previously reported, percutaneous closure of PVL still faces several issues, particularly the lack of a specific device designed to treat PVL and hence off-label use of available devices; difficulty in crossing the leak due to the position or anatomical configuration of the defects, which can be serpiginous and/or rigid due to calcification of the annulus or to the valve annulus itself; and interference of the device with the function of the prosthetic valve, making it impossible to release the device.3,8 The operator's experience is crucial to the success of the intervention and may have accounted for our initial difficulties with this technique. The type of approach may also affect the final result, and a transapical approach may offer an alternative option in cases where transseptal or retrograde approaches are not feasible. The choice of device was at the discretion of the operator, based on echocardiographic and radiographic interpretation.

Procedural and clinical success as well as complication rates were acceptable for these 18 high surgical risk patients. A team approach, including transesophageal echocardiography specialists, interventional and general cardiologists and anesthesiologists, facilitated these outcomes. Such interventions are lengthy, as demonstrated by the relatively long fluoroscopy times, and can be challenging and technically demanding; close cooperation between team members in preprocedural planning and during and after the intervention are therefore essential.

Our experience of PVL closure in a predominantly elderly, high-risk population was favorable in terms of technical success, clinical improvement and safety. The procedure is complex and a second intervention may be necessary.

Percutaneous closure of PVLs may be a feasible and valid alternative treatment strategy for selected symptomatic patients refractory to medical therapy and at high surgical risk. A collaborative effort between a skilled interventional team can result in successful outcomes, apparently with lower morbidity and mortality rates in comparison to surgical series.

The authors have no conflicts of interest to declare.