Paravalvular Leaks and Ventricular Septal Defects: Endovascular Approaches to Treatment

Paravalvular leak (PVL) is an abnormal communication between cardiovascular chambers adjacent to a prosthetic valve. The incidence after surgical valve replacement is rare, ranging from 2% to 10% in the aortic position and from 7% to 17% in the mitral position; no more than 5% of such patients are symptomatic.1 Symptoms predominantly include congestive heart failure and hemolytic anemia. Paravalvular leaks are most often seen in association with transcatheter aortic valve replacement, and 6% to 21% of those cases are moderate to severe. Nonetheless, PVLs in all prosthetic-valve types are associated with the potential of death.2 Ventricular septal defect (VSD) is the second most common congenital heart defect after bicuspid aortic valve. Acquired VSDs can occur after surgery or as a rare consequence of myocardial infarction (MI) and are associated with a high mortality rate. Surgery has traditionally been the standard treatment of clinically significant PVLs and VSDs. Transcatheter closure of these lesions now provides an alternative means of correction, as surgical options can be technically challenging, have high recurrence rates, and are associated with significant morbidity and mortality rates. This review explains briefly, but in some detail, the role of multimodality imaging in evaluation and in procedural guidance, sets forth procedural techniques (with a focus on access approaches), and discusses clinical outcomes of PVL (Figs. 1 and ​and2)2) and VSD (Fig. 3) closure. Fig. 1 Percutaneous transapical closure of paravalvular leak (PVL), as seen during the procedure. A) Three-dimensional transesophageal echocardiogram from the surgeon's view (left atrial perspective) reveals multiple large PVLs on the lateral (6 to 11 ... Fig. 2 Percutaneous transapical closure of paravalvular leak (PVL), as seen after the procedure. A) Postprocedural computed tomographic angiography (CTA)-fluoroscopy fusion image identifies the outlined mitral prosthetic frame (yellow) with multiple AMPLATZER ... Fig. 3 Percutaneous transapical closure of ventricular septal defect (VSD). A) and B) Computed tomographic angiography (CTA) with 3-dimensional (3D) reconstruction shows a large postsurgical perimembranous VSD below the surgical aortic prosthesis. With ... Multimodality imaging plays a pivotal role in patient selection, preprocedural planning, and intraprocedural guidance of PVL and VSD closure. These imaging techniques include 2- and 3-dimensional (2D/3D) transthoracic and transesophageal echocardiography (TEE), computed tomographic angiography (CTA) with 3D and 4-dimensional (4D) reconstruction, and, more recently, fusion imaging. Fusion imaging is the integration of either real-time TEE or pre-acquired CTA with fluoroscopy. Transesophageal echocardiography can localize paravalvular regurgitation or left-to-right shunting and can help in the evaluation of the communication's severity. It can also be used to analyze the size and shape of both a PVL and VSD. Of equal importance is CTA with 3D/4D reconstruction using volume-rendering techniques. It is now possible to visualize these defects with great detail, better defining their commonly indeterminate or irregular shapes and serpiginous tracks. The most common location for an aortic PVL is in the posterior (noncoronary) cusp; for a mitral PVL, it is in the aortic–mitral curtain (10 to 1 o'clock) and posteroseptal (3 to 6 o'clock) positions; and for a post-myocardial infarction VSD, it is in the trabecular muscular septum, usually apical. Percutaneous access to the defect is determined by the location of the defect, the size and direction of the track, the angle of entry, and the presence of obstruction(s) along its course, such as vascular access difficulties, calcification, and mechanical valves that hinder entry. The creation of exteriorized arteriovenous and arteroarterial rails can provide complete control and improved support for sheath and device delivery. The most common approaches (from most to least common, at our center) for aortic PVLs are transaortic, transapical, and transseptal; for mitral PVLs, they are transapical, transseptal, and transaortic; for mid-muscular, posterior, and apical VSDs, they are right internal jugular vein to transaortic rail and femoral vein to femoral vein transseptal rail; and for high-muscular and perimembranous VSDs, they are transapical and femoral vein to transaortic rail. A percutaneous transapical approach provides a direct path to most of these left ventricular defects and can be performed safely.3 Using CTA-fluoroscopy fusion imaging with the HeartNavigator (Philips Healthcare; Best, The Netherlands), the interventionalist can segment the pre-acquired CTA with important landmarks (for example, skin entry point, left ventricular epicardial entry point, PVL, and VSD) so identified that they are in a direct line, away from the lung and the coronary arteries. After registration with X-ray, outlines of the cardiac structures and landmarks are overlaid onto live fluoroscopy, to guide the interventionalist. A major issue regarding treatment of PVLs is the absence of dedicated delivery systems and devices designed for percutaneous closure. Devices currently in use—that is, the AMPLATZER family of closure devices (St. Jude Medical, Inc.; St. Paul, Minn)—are designed for other cardiac defects and are used off-label. Multiple devices can be deployed across a leak simultaneously to conform with and seal the paravalvular space. To close the congenital and post-surgical types of VSDs, the AMPLATZER Muscular VSD Occluder is typically sized to fit the size of the track. For post-myocardial infarction VSDs, an AMPLATZER Post-Infarction Muscular VSD Occluder (CE marking) can be used, because its longer waist and larger widths accommodate the damaged muscular septal tissue after a myocardial infarction. For this application, the interventionalist typically chooses devices that are oversized by 50%. The technical success rate of percutaneous paravalvular-leak closure ranges from 77% to 86%, and clinical success ranges from 67% to 77%.4,5 Survival rates vary in accordance with the series, from as high as 86.5% at 18 months to as low as 64.5% at 3 years, a variation that is probably associated with the incidence of medical comorbidities in PVL patients. Percutaneous closure rates are greater than 95% for the congenital type of VSD, but data are scant on postsurgical and post-myocardial infarction VSDs. The currently available data suggest that transcatheter closure can be safe and effective in post-myocardial infarction VSD patients.6 Endovascular approaches for the treatment of structural heart disease, including the closure of PVLs and VSDs, have grown substantially over the past decade and are a therapeutic option for the high-risk patient. As patient and procedural complexity escalate, we find that the use of multimodality imaging and alternative access approaches (such as percutaneous transapical access) increase our understanding of these transcatheter techniques and broaden their applications.