Tricuspid valve-in-valve/valve-in-ring therapy

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.