Background
Transcatheter valve replacement is becoming an increasingly favored option to treat a failing tricuspid bioprosthetic valve (BPV). As clinical experience grows and valve technology expands, the option of implanting a new tricuspid valve in the cardiac catheterization laboratory is a viable alternative to a conventional surgical valve replacement therapy, which remains relatively high risk. Patients may have undergone tricuspid valve replacement for underlying congenital heart disease (such as Ebstein anomaly or tricuspid valve dysplasia) or to treat functional tricuspid regurgitation when valve repair is not possible. BPVs are utilized most commonly for surgical tricuspid valve replacement. Often these patients have underlying right ventricular dysfunction and other issues that may complicate reoperation or increase surgical risk. Therefore catheter-based tricuspid valve-in-valve (TVIV) therapy is an attractive option, especially in patients who have undergone repeated median sternotomy and elderly patients who are likely to have significant comorbidities.
In addition, patients who have undergone tricuspid valve repair utilizing annuloplasty ring may be offered transcatheter valve replacement therapy, but are less optimal candidates due to the elliptical nature of annuloplasty ring anatomy, with potential for significant residual “paravalvular” leak after valve-in-ring deployment.
Indications
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Symptomatic severe tricuspid bioprosthesis stenosis or regurgitation.
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BPV thrombosis should first be treated with a trial of anticoagulation therapy and/or thrombolytic therapy before undergoing valve-in-valve (VIV).
Contraindications
Active endocarditis is considered a contraindication to TVIV. Device leads for defibrillators and pacemakers are not a contraindication for the procedure. Leads that are external to the sewing ring are ideal; however, transvalvular device leads can also be “trapped” between the transcatheter valve and surgical valve without affecting lead function in limited case series, although it is preferable to have an alternative lead available for “backup pacing” in patients who are pacemaker dependent.
Workup for valve-in-valve procedure
Transthoracic or transesophageal echocardiography is usually sufficient for precatheterization valve evaluation and determination of need for therapy. Computed tomography (CT) with 3D reconstruction is typically only needed when considering tricuspid valve-in-ring therapy, and a 3D print model may be helpful for preprocedural planning.
If available, the manufacturer’s card or the surgical operative report is reviewed to check for the type and size of the surgical prosthesis. After that, transcatheter valve sizing is done using the VIV mobile application, which gives the transcatheter valve sizing according to the BPV true internal diameter. Sizing can also be confirmed using a preprocedural cardiac CT scan (contrast CT if possible), which measures the actual internal diameter that can sometimes be smaller than the expected internal diameter if there is stenosis or pannus formation. In cases where prosthesis sizing remains questionable by imaging, balloon sizing during the procedure can be performed by inflating a balloon of a particular size across the surgical valve and looking to see if a waist develops, which is a sign of adequate seal. The waist can then be measured to determine the internal diameter.
Off-label use of currently available valve technology is planned; the two valves most commonly implanted are the Melody (Medtronic, Inc., Minneapolis, MN) and Sapien S3 (Edwards Lifesciences, Irvine, CA).
Valve selection
Sizing of the surgical BPV can be done with traditional known methods (VIV applications) or by balloon sizing at the time of the procedure to determine the inner diameter of the existing BPV ( Fig. 24.1 ). The Melody valve system can be safely implanted into all BPVs with an outer diameter of 25 mm at the time of surgical implant. The delivery catheter for the Melody is a 22-mm, balloon-in-balloon, fully covered system that expands the Melody valve to an outer diameter of approximately 24 mm when fully deployed. If the balloon-sizing method used at the time of the procedure demonstrates that the waist on the balloon is less than 24 mm, then a fully deployed Melody will fit well, even when manufacturer’s specifications indicate a much larger valve; this is typically due to leaflet restriction, calcification, thickening, and/or pannus ingrowth. Implantation of the Sapien valve into a BPV 27 mm or greater is typically performed, again with size being determined by typical VIV specifications. Certain types of BPV may be fractured to improve inner diameter. Consideration may be given to fracture of the existing BPV, particularly if smaller diameter, with a high-pressure balloon prior to valve implant.
Procedure: Step-by-step approach
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If preprocedural transthoracic echocardiographic (TTE) images are adequate or intracardiac echocardiography (ICE) is available, the procedure can be done under conscious sedation. Alternatively, if transesophageal echocardiogram is required for intraprocedural imaging, general anesthesia is often used.
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Access is obtained in the femoral vein using a 7F sheath under ultrasound guidance, using usual techniques with or without preclosure with one Perclose device.
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A small arterial sheath is often also used in the femoral or radial artery for hemodynamic monitoring.
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A balloon wedge catheter (Teleflex, Morrisville, NC) is then advanced into the pulmonary artery and placed in a wedge position. The left pulmonary artery is preferred over the right, as it may provide better alignment for positioning and deployment of the device.
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Once the balloon wedge catheter is in position, an exchange-length Amplatz super-stiff 0.035″ wire is then advanced through the balloon wedge catheter and placed distally.
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The balloon wedge catheter is then removed over the stiff wire.
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The 7F sheath is removed and is upsized to a 14F or 16F Edwards eSheath over the stiff wire.
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The Edwards Sapien S3 valve is then mounted with an atrial orientation of the skirt.
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The transcatheter delivery system is then inserted into the inferior vena cava (IVC) and assembled, then positioned across the tricuspid prosthetic valve sewing ring using an orthogonal fluoroscopic angle (see Fig. 24.2 ). The position of the Sapien S3 valve should be positioned such that the central marker is just ventricular to the prosthesis sewing ring.
Fig. 24.2
(A) A small curve Safari wire is positioned in the dilated right ventricle, and the Sapien valve is advanced into the existing bioprosthesis (St. Jude Epic with thin filament visualized in annulus/sewing ring). Adjustment would be made with respect to positioning this valve more proximally before deployment is carried out. (B) Small curve Safari wire positioned with curve down in the apex of the dilated right ventricle for positioning of the Sapien valve into this Hancock II bioprosthetic valve.
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After confirming positioning on fluoroscopy, deployment starts with a slow inflation. Once a stable position is reached, deployment is completed by fully inflating the balloon over a period of 6 to 8 seconds. Adequate anchoring is confirmed fluoroscopically by seeing a waist around the transcatheter ring, as well as using echocardiography to assess for the presence of periprosthetic or prosthetic leaks. Rapid pacing is not needed for this procedure; however, in rare instances, transcatheter valve positioning can be challenging and rapid pacing can be helpful. This can be done using right atrial, left ventricular pacing with a balloon-tipped pacemaker or coronary artery septal branch pacing through a coronary wire insulated in a microcatheter and connected to the pacemaker externally.
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The delivery system is then retracted over the wire into the IVC.
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Once adequate deployment is verified, the balloon wedge catheter is then brought up again over the stiff wire into the wedge position. The stiff wire is then carefully removed.
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Finally, the femoral vein sheath is removed and the Perclose suture is deployed to achieve adequate hemostasis.
An acceptable result is a well-seated transcatheter valve with some waist seen at the areas of contact with the surgical valve ring, with no evidence of more than mild periprosthetic or prosthetic leak, as well as less than 5 mmHg diastolic gradient across the tricuspid valve.
Tips, tricks, and pitfalls
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Access sheath: Femoral venous access is most commonly used, although internal jugular access is also possible. When planning for Melody valve deployment, the Ensemble delivery system is designed to be advanced percutaneously without a guiding sheath, as the valve remains fully covered until advanced into the desired position. A 22F DrySeal sheath (Gore Medical, Newark DE) will accommodate the 22F delivery system without the need for multiple catheter exchanges over the guidewire. A 16F eSheath is used for Sapien implant.
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Wire positioning: Standard right heart catheterization is performed during this procedure. In the setting of severe tricuspid stenosis and/or regurgitation, it may be difficult to cross easily, and biplane visualization of the valve ring is very useful. A Glidewire may be used to assist catheter crossing. If a pulmonary artery (PA) wire is planned, the 7F balloon wedge catheter can be positioned deeply in the right or left pulmonary artery with the use of this angled Glidewire. An exchange-length 0.035″ wire, typically a Lunderquist (Cook Medical, Bloomington, IN) or Amplatz super-stiff or extra-stiff (Boston Scientific, Marlborough, MA) wire, is positioned deep in the PA for most valve deployments. With the balloon inflated on the wedge catheter to maintain position of the tip, the stiff exchange wire is then positioned to the tip of the wedge catheter and left in place as the wedge catheter is withdrawn. The left PA may be favored to visualize the tip of the wire during valve manipulation, particularly when using the Sapien system and mounting the valve onto the balloon in the IVC. When using a stiffer wire, it is important to monitor the wire tip at all times to prevent distal PA branch injury.
An alternative method is to position a small curve Safari wire (Boston Scientific, Marlborough, MA) directly into the apex of the right ventricle (RV) ( Fig. 24.3 ). This technique is particularly useful when the RV is known to be severely dilated, as the wire curve can be accommodated in the apex of the RV; this technique is unlikely to be successful when the RV is smaller or hypercontractile. To deploy the stiff Safari wire successfully into the RV, the right atrial–to–tricuspid valve curve needs to be maintained with a steerable sheath such as the Agilis (Abbott, Abbott Park, IL) or Dexterity sheath (Spirus Medical, Stoughton, MA). A “mother–child” catheter combination of 6F multipurpose guide with 5F multipurpose catheter or the 7F balloon wedge catheter can then be manipulated into the apex of the RV for positioning of the Safari wire.
