ViV: A Second Chance for Failing Heart Valves

Bioprosthetic valves are frequently found in use due to an increased incidence of heart valve disease with the aging population and their inability to function without life-long anticoagulation. Nonetheless, these valves are not wonderful just as they have their own issues. Bioprosthetic valves can fail over time due to structural degeneration, requiring reintervention. In the past, redo surgeries have been favored for such cases but this comes at a high risk to specifically high-risk individuals. In this article, we discuss advanced therapeutic options for treating degenerated surgical prosthesis valves that have failed, concentrating on transcatheter valve-in-valve (ViV) procedures as less invasive alternatives to conventional surgery.

The development of bioprosthetic heart valves radically transformed the management of valvulaopathy, providing anticoagulation sparing options for patients compared to mechanical alternatives. While these bioprosthetic valves were initially considered to offer the solution that some of them have, it soon became apparent there is wear and tear on this kind as well. Consequently, a substantial population of patients with bioprosthetic valve replacement is confronted by the necessity for redo surgery because of structural valve degeneration. This review outlines the reasons behind surgical bioprosthesis failure and addresses novel transcatheter technologies revolutionizing valve replacement strategies.

The Material Ethylene Oxide, Bioprosthetic Valve Dysfunction

Whereas significant advantages of bioprosthetic valves include reduced the risks for thromboembolism and elimination of need for anticoagulation; these prostheses are subject to structural degradation. This process may take 10 to 20 years, depending on the age of a patient and whether other diseases exist at baseline; it is also dependent upon valve type. These processes are the key modalities of bioprosthetic valve failure: leaflet calcification, tissue degeneration and pannus or thrombus formation. These alterations cause stenosis or insufficiency of the valve, thus impairing its function and requiring reintervention.

Problems with Repeat Surgery

What we have needed to do is redo valve replacement surgery, a traditional approach for patients with failed bioprosthetic valves. The risks are also higher with redo surgeries, which have the potential for greater blood loss, infections or stroke; longer recovery times and a statistically significantly increased operative mortality rate of 1.75%. Redo surgery may often be less feasible in a patient who is elderly and rife with comorbidities, as these choices are typically more risky than the alternative.

Transcatheter Valve-in-Valve (ViV) Interventions

Because of the complexity in redo surgery, transcatheter valve-in-valve (ViV) has been used as an alternative to this kind of reoperation for failed bioprosthetic valves. In other words, these procedures require the implantation of a new transcatheter valve inside an old surgical bioprosthetic to restore its function without the need for open-heart surgery. As the transcatheter aortic valve replacement (TAVR) evolved, it set the stage for ViV procedures that now may be conducted in any previously placed bioprosthetic heart position including: aortic, mitral, tricuspid and very recently pulmonary.

3. Technical considerations and challenges

ViVs are an attractive alternative to redo surgery; however, decrecomes at a price. Several factors determine the success of a ViV procedure, including stent frame expansion within a rigid metallic valve and calcifications in non-metallic valves that are too large to reconfigure. The most significant technical challenge lies in securely deploying a transcatheter valve inside the degenerated bioprosthesis, especially when it has become deformed or calcified over time.

Results and Clinical evidence

Evidence from a burgeoning number of safety and feasibility studies outlining ViV procedures, which seem to be safe and effective in high-risk patients. ViV procedures have been reported to demonstrate high procedural success rates, low complication rates and significant symptomatic and quality of life improvements. In fact, another excellent example is Global Valve-in-Valve Registry outcomes for need in people with unfavorable surgical ris k features continue to suggest very low mortality and good hemodynamic performance improvement.

TAV-in-SAV procedures

By far, the most common use of ViV technology has been in the aortic position with transcatheter (TAV-in-SAV) TAVR procedures now an accepted standard for patients when bioprosthetic AV www.interventionalnews.com 10 valves fail. TAV-in-SAV procedures consist in placing a transcatheter valve inside the failing surgical aortic valve, usually transfemorally. It has demonstrated good efficacy and safety, procedural success rates have been high with very low incidences of complications such as coronary obstruction or paravalvular leak.

Transcatheter Mitral Valve-in-Valve (TMV-in-SMV)→

Transcatheter mitral valve-in-valve (TMV) and the similar in-ring (TiR) positioned valves are a more recent application of ViV technology, but have gained quick acceptance as an alternative to redo open-heart surgery to replace failed prosthetic MHVs. The mitral position poses a particular set of challenges due to the proximity between the mitral valve and left ventricular outflow tract (LVOT) as well as complex anatomy in relation to global orifice restriction. However, recent advances in imaging and device technology have made TMV-in-SMV procedures more practical and resulted in successful outcomes among high-risk patients.

Transcatheter Valve-in-Ring (ViR) and ViMAC

ViV procedures are an aside but transcatheter valve-in-ring (ViR) [4] and valve-in-mitral annular calcification (MAC) types have theoretical new treatment options for patients who failed their surgical repair with artificial documents or severe MAC respectively. In the Reliant/Nord R/WAVE and Correx/Ismatec studies were defined ViR procedures as percutaneous valve in ring, which refers to a transcatheter heart valve deployed within a previously implanted annuloplasty ring that failed (purposefully or by itself), while those involving heavily calcified mitral rings have been labeled variflare-in-mitro-annular-calcification (ViMAC) process. These are technically challenging approaches, but they provide a less invasive option for high-risk patients who have already undergone redo surgery.

Eligibility and Preparation Before the Procedure

The overall success of VIv procedures is dependent on appropriate patient selection and careful procedural planning. Important factors to consider include the patient's general condition, size and type of failing bioprosthetic valve leaflets, concomitant conditions (ie coronary obstruction / LVOT obstruction), comporomorbidity. Pre-procedural planning made feasible by advanced imaging modalities like 3D echocardiography and CT are essential for measurement of the valve annulus and assessment of surrounding anatomy with precision.

Future strategy and innovations

With the field of transcatheter valve replacement rapidly developing, current research and innovation are seeking to further enhance safety and efficacy in ViV procedures. Improved durability, hemodynamic performance and ease of implantation also are being engineered into the next generation of transcatheter valves. Moreover, improvements in imaging and computational modeling have allowed these ViV procedures to be tailored more precisely at the patientlevel with a viewto optimizing outcomes.

Challenges and Considerations

Although ViV procedures offer hope, key challenges still stand in the way of their broad utilization. Cost is also a significant barrier, especially in countries like the USA where healthcare resources are not evenly distributed. Similarly, the ViVphericity of valve-in-valve (ViV) procedures has advanced rapidly and its technical complexity requires specialized training and expertise that may limit its availability to selected centers. Lastly, the experience with trans-catheter valves from ViV setting especially in long term durability and performances remains relatively poor and further research is required to talk on their broad applicability.

Conclusion

The failed previous surgical valve replacement is now an increasingly common clinical problem in patients with valvular heart disease. Although redo surgery has long been the mainstay, transcatheter valve-in-valve (ViV) procedures are an increasingly viable alternative for high-risk patients. These operations have shown good safety profiles, efficacies and quality of life measures in the study pool underscoring them as an alternative for non-surgical candidates. Since the field is still growing, more research and innovation will play a key role in improving these methods for use on larger patient populations. Ultimately, the aim is to offer patients with failed bioprosthetic valves a safe and effective treatment option compared by redo surgery — ultimately improving their quality of life and reducing risks related reintervention.