Paravalvular leak (PVL) occurs in 5% to 17% of patients after valve replacement surgery. Although the majority of PVLs are subclinical, some patients develop symptoms of heart failure, hemolysis, or both, requiring intervention. Surgical repair or valve re-replacement is the historical gold standard for the management of symptomatic PVL, but is associated with significant morbidity and mortality, even in modern practice. Percutaneous PVL closure has proven to be a feasible alternative to repeat surgery, with safety and efficacy demonstrated in several studies. Techniques and outcomes of percutaneous PVL closure differ significantly according to the prosthesis location (aortic vs. mitral). This chapter focuses on summarizing the contemporary techniques and outcomes of percutaneous aortic PVL closure.
Clinical impact of aortic PVL
The incidence of PVL is higher among patients with mitral prostheses than those with aortic prostheses. It is also higher in patients undergoing transcatheter vs. surgical aortic valve replacement. Although symptomatic aortic PVL is known to negatively affect long-term outcomes, data from the transcatheter aortic valve replacement (TAVR) literature suggest that more than mild aortic PVL is associated with worse long-term survival even in asymptomatic patients. However, in current practice, the majority of patients considered for PVL closure are referred due to heart failure, progressive ventricular dilatation, unexplained dyspnea, or hemolytic anemia. Once the decision is made to offer percutaneous aortic PVL closure to the patient, detailed pre- and intraprocedural imaging assessment is necessary to understand the mechanism and anatomic characteristics of the leak and to select the optimal closure technique.
AHA guidelines
| IIa | B | Percutaneous repair of paravalvular regurgitation is reasonable in patients with prosthetic heart valves and intractable hemolysis or New York Heart Association (NYHA) class III/IV heart failure who are at high risk for surgery and have anatomic features suitable for catheter-based therapy when performed in centers with expertise in the procedure. |
Multimodality assessment of the paravalvular leak
Preprocedural imaging
Procedural success relies on full understanding of the location, number, and severity of PVL(s). Although aortic PVLs are often detected on transthoracic echocardiography (TTE), detailed assessment of their characteristics often requires additional imaging. Transesophageal echocardiography (TEE) provides excellent delineation of the location and the severity of the leak. Cardiac computed tomography (CCT) offers incremental value in identifying the path of the leak, measuring its dimensions, distances from the right and left coronary ostia, and predicting the ideal fluoroscopic angles for the closure procedure ( Fig. 13.1 ). Meticulous planning increases the likelihood of successful closure and decreases the procedure duration, radiation exposure, and contrast use.
We utilize a multifaceted approach incorporating echocardiographic, invasive hemodynamic, and angiographic data to grade the leak to mild, mild to moderate, moderate, and severe. Common echocardiographic parameters used include (1) PVL jet width measured in the short and long axis at the level of the sewing ring and in the left ventricular (LV) outflow tract, (2) diastolic flow reversal in the descending thoracic and abdominal aorta, (3) deceleration rate by pressure half-time, and (4) regurgitant volume and regurgitant fraction. Invasive hemodynamics and aortic root angiography are often used to ascertain the severity of regurgitation in equivocal cases.
Intraprocedural imaging
Closure of simple leaks can be guided by TTE, but complex leaks (multiple, serpiginous, posterior, etc.) require TEE or intracardiac echocardiography (ICE) guidance. Both TEE and ICE offer high-resolution imaging, but TEE has the additional advantage of biplane (also referred to as x-plane ) and 3D imaging. TEE requires a dedicated echocardiographer and deeper sedation or general anesthesia. When TEE is used to guide the closure procedure, a standardized nomenclature based on fixed anatomic reference points is necessary to ensure efficient communication between the echocardiographer and interventionalist.
Whereas mitral PVLs are usually localized based on their location in the surgical 3D-TEE view (anterior, posterior, medial, lateral), aortic PVLs are best localized relative to their position to the aortic cusps (left, right, and noncoronary cusps).
When ICE is utilized, a dedicated venous access (8 to 10F) is obtained, and an ICE probe (AcuNav, Siemens-Acuson, Mountain View, CA, or View-Flex, Abbott Vascular, St. Paul, MN) is positioned in the right ventricular outflow tract. This view affords excellent imaging of the aortic valve (AV) in the short and long axis.
Percutaneous closure techniques
Vascular access and leak crossing
We place an 8F arterial sheath and a Perclose suture (Abbott Vascular, Santa Clara, CA) in the common femoral artery. We then telescope a 125-cm, 5F, multipurpose coronary or vertebral catheter through a 100-cm 6F guiding catheter (usually Amplatz Left-1) adjacent to the leak and probe the leak with a 0.035-inch stiff-angled Glidewire (Terumo, Tokyo, Japan). After advancing the wire into the LV, the 6F guide catheter is telescoped toward the apex over the wire and the 5F catheter, which acts as a dilator to the guiding catheter. The wire is then removed and exchanged with a manually curved Amplatzer extra-stiff wire or a precurved extra-stiff Safari wire (Boston Scientific, Marlborough, MA). The extra-stiff wire serves as the platform to advance a 5 to 8F Flexor Ansel, Raabe, or Shuttle sheath (Cook Medical, Bloomington, IN) or Destination sheath (Terumo, Tokyo, Japan) to the LV. Most of these sheaths are available in 90- to 100-cm lengths, which is adequate to reach the LV in the majority of patients. Shuttle sheaths (4 to 6F) are available in a 110-cm length and might be utilized in taller patients.
Radial access can be used in simple leaks when use of only one occluder device is anticipated, but we generally prefer the femoral route because closure techniques for larger leaks often require multiple catheter exchanges and large-bore access. We administer intravenous heparin and ensure an activated clotting time to be above 250 seconds during the procedure.
Choice of closure device
The shape of the PVL may be complex and variable, but is often crescentic. Hence, an oblong device, such as the Occlutech PLD device (Occlutech, Jena, Germany) or the Amplatzer Vascular Plug 3 (AVP-3) (St. Jude Medical, St. Paul, MN), may conform better to the anatomy of the leak ( Fig. 13.2 ). , The Occlutech PLD device is the only device that was specifically designed for percutaneous closure of PVL. The use of oblong devices has been associated with a trend toward a more complete PVL reduction in the European experience. However, these devices are not approved by the Food and Drug Administration (FDA) and thus are not available in the United States. We utilize the AVP-II in the majority of closures of parasurgical prosthetic valve leaks and either the AVP-II or IV for the closure of paratranscatheter prosthetic valve leaks. Amplatzer Vascular Plugs II are available in a wide range of sizes (diameters 3 to 22 mm) and can be delivered via 4 to 7F sheaths or 5 to 9F guiding catheters. Most PVLs are of small-to-medium sizes, and therefore 8- to 14-mm AVP-II are the most commonly utilized occluders.
Amplatzer Vascular Plugs IV have a markedly lower profile compared with AVP-II, and thus can be easily delivered via any catheter that can accommodate an 0.035-inch wire. However, AVP-IV are only available in 4- to 8-mm diameters, and hence their utility is limited to smaller PVLs. We oversize our occluder device by at least 50% relative to the largest diameter of the leak to ensure an adequate seal of the leak and minimize the risk of device embolization.
Leak closure techniques
Once the leak is crossed, three common techniques are utilized to deliver the closure device(s). Although switching between techniques during the procedure is possible, selecting the appropriate technique at the outset increases the efficiency and the safety of the procedure.
Catheter-only technique ( Fig. 13.3 A): With this method, after the delivery sheath/catheter is advanced in the LV, the extra-stiff wire is removed and the occluder is directly deployed across the leak. We utilize this technique when crossing of the defect is smooth and the leak is circular in shape and likely to seal with one device. However, a disadvantage of this technique is the loss of guidewire position across the leak at the time of device deployment.
