5.3 Novel Devices for Interventional Tricuspid Repair: A Better “Mouse Trap”?

These proceedings summarize the educational activity of the 17th Biennial Meeting of the International Andreas Gruentzig Society held January 30 to February 2, 2024 in Chiang Rai, Thailand.

Faculty Disclosures     Vendor Acknowledgments

2024 IAGS Summary Document

Statement of the problem or issue

The range of tricuspid valve pathology is huge, and it's even more heterogeneous than mitral valve pathology (Figure 1).

Figure 1. Examples of Tricuspid Valve Pathology.

Annular dilatation of the tricuspid valve is the rule, and this leads to substantial tricuspid regurgitation, which then leads to volume overload of the right ventricle, and this results in massive dilatation of the right heart (Figure 2).

Figure 2. Annular dilatation of the tricuspid valve. Dilatation of the right heart.

Gaps in current knowledge

1. Current procedures to repair or replace the tricuspid valve have many challenges. They are often long and tedious, with numerous technical challenges including imaging and the assessment of results. New technologies are being developed which will help address many of these challenges, but at present they remain in the early stages of design and development, and very early-stage clinical research.
2. An important issue is the appropriate time to intervene. Historically, there has been little we can offer patients with tricuspid regurgitation other than diuretics or high-risk surgery. Intervening too early would potentially expose a patient to many more years with prosthetic materials in the heart. On the other hand, intervening too late may result in missing the “therapeutic window.” Tricuspid valve disease is in many ways a systemic disease, and new clinical severity scores such as TRIO have been developed for better risk prognostication.
3. Assessing and grading the severity of tricuspid regurgitation remains extremely challenging and attempts to standardize this are underway.

Possible solutions and future directions

The focus of this presentation is on 3 new technologies that hold the promise of safety and efficacy, along with shortened procedure times. None of these are FDA approved, and all 3 are in the early stages of testing in humans. Final judgment on applicability must await the results of early feasibility studies. Many other tricuspid technologies, for example, annuloplasty, are also being developed, but are beyond the scope of this presentation.

One technology that is fairly far along in development comes from a company called V-Dyne, based in Minneapolis-St. Paul, Minnesota. It has a unique design, and anchors onto the tricuspid annulus using a side-biting mechanism. It is delivered via the right femoral vein access and IVC. The valve is removable, repositionable, mobile, and can be aligned precisely to the tricuspid annulus. It does not depend on tricuspid leaflets for anchoring, and in selected cases pacemaker leads can be accommodated. It is currently being evaluated in an early feasibility study (Figure 3).

Figure 3. The V-Dyne Tricuspid Valve.

A second novel transcutaneous tricuspid valve replacement system is from Laplace Interventional, also based in Minneapolis-St. Paul Minnesota. This is a unique valve that is delivered via the right internal jugular vein. This valve is anchored into the RVOT and posterior tricuspid annulus; it does not require leaflet anchoring. Most of the procedure is performed using fluoroscopy. This technology has just begun early feasibility studies in the United States (Figure 4).

Figure 4. The Laplace Tricuspid Valve.

A final new technology to mention is the 2 cross-caval systems from Innoventric. These are true cross-caval systems in that there are no materials positioned in the tricuspid valve or annulus itself. Here, the function of the tricuspid valve is replaced by a tubular valve-equivalent structure placed in the superior and inferior vena cava (Figure 5). The Trillium system has small flaps on the struts that open and close and act as multiple small valves. The Unica system has 2 actual valves, one in the superior vena cava and one in the inferior vena cava. These 2 valves permit blood to flow from both cava into the right side of the heart but not backwards. These bicaval systems may be useful in a broad range of patients, particularly those with a very large tricuspid annulus. A potential downside is continued dilatation of the right atrium, since regurgitation of the valve itself is not affected. On the other hand, the body would remain protected from the effects of severe tricuspid regurgitation, and so patients are likely to benefit from this. This technology has been tested in humans overseas and is about to enter the United States in an early feasibility study.

Figure 5. The Innoventric Heterotopic Cross-Caval Portfolio.

So, these illustrate some of the exciting new possible technologies that are coming into the tricuspid valve space.

Conclusions. Innovation and investment are continuing rapidly in the tricuspid regurgitation space. No single technology has yet proven itself applicable to the entire spectrum of patients with tricuspid regurgitation, and it is likely that multiple technologies will be required in the future given the heterogeneity of tricuspid regurgitation pathology. The next few years will see an acceleration of research and development in this area.

Reference

1. Welle G, Hahn R, Lindenfeld J, et al. New approaches to assessment and management of tricuspid regurgitation before intervention. JACC Cardiovasc Interv. 2024,17(7):837–858. doi.org/10.1016/j.jcin.2024.02.034