Recent advances in aortic valve replacement for aortic stenosis

Sutureless Valves, a "Wireless" Option for Patients With Aortic Valve Disease: JACC State-of-the-Art Review

Transcatheter technologies triggered the recent revision of the guidelines that progressively widened the indications for the treatment of aortic stenosis. On the surgical realm, a technology avoiding the need for sutures to anchor the prosthesis to the aortic annulus has been developed with the aim to reduce the duration of cardiopulmonary bypass and simplify the process of valve implantation. In addition to a transcatheter aortic valve replacement (TAVR)-like stent that exerts a radial force, these so-called "rapid deployment valves" or "sutureless valves" for aortic valve replacement also have cuffs to improve sealing and reduce the risk of paravalvular leak. Despite promising, the actual advantage of sutureless valves over traditional surgical procedures (surgical aortic valve replacement) or TAVR is still debated. This review summarizes the current comparative evidence reporting outcomes of "sutureless valves" for aortic valve replacement to TAVR and surgical aortic valve replacement in the treatment of aortic valve stenosis.

The Longest Known Survival of a Patient With Bioprosthetic Aortic Valve Replacement: A 42-Year Follow-Up

Aortic valve replacement (AVR) is a frequently performed procedure for treating aortic valvulopathy. AVR involves replacing the damaged aortic valve with either a mechanical or a bioprosthetic valve. While many factors are involved when selecting between the two options, age and patient preference are the deciding factors at this point. Mechanical valves demonstrate long-standing durability that overlaps with the accompanied bleeding risk due to lifetime anticoagulant therapy, making them a more favorable choice for younger patients. Bioprosthetic valves are preferred for older patients as they show a reduced risk of thrombogenicity. However, bioprosthetic valves have a higher incidence of structural valve degeneration (SVD) than mechanical valves. Our case report focuses on a 76-year-old patient who had undergone an AVR with a bioprosthetic valve at the age of 33, which has still not demonstrated any valve deterioration. As the longest known case of bioprosthetic durability, this patient provides useful data for designing bioprosthetic valves more resistant to structural degeneration and thereby better suited to younger patients or those at higher risk of bleeding.

In vitro comparison of everting vs. non-everting suture techniques for the implantation of a supra-annular biological heart valve

Background

The aim of this study was to evaluate the hemodynamic effect of different suturing techniques for aortic valve replacement (AVR) in vitro. Whether or not the applied suturing technique impacts the outflow tract diameter by narrowing the annulus diameter was examined.

Methods

The commonly applied non-everting pledget forced suture technique (NE, n=13) was compared with an everting pledget forced suture (ET, n=13) for AVR using the 25 mm St. Jude Trifecta aortic valve. Hemodynamic parameters were obtained in a pulsatile flow simulator. A high speed camera captured the visual aspects of the suturing technique.

Results

Despite some kind of left ventricular outflow narrowing due to protruding pledgets using the NE suture technique, mean pressure gradients of both techniques were nearly similar (NE 5.88±2.7 mmHg, ET 5.23±1.31 mmHg, P=0.44). Closing volume (NE 3.16±0.48 mL; ET 3.51±0.68 mL; P=0.14) and the leakage volume (NE: 8.09±2.53 mL; ET: 8.35±3.65 mL; P=0.83) also showed no differences.

Conclusions

AVR using either suturing techniques leads to a similar hemodynamic performance in vitro. The impact of the suturing technique may be higher in a smaller annulus. Therefore, further studies using smaller prostheses are necessary.

Transcatheter Aortic Valve Replacement versus Surgical Aortic Valve Replacement: A Review of Aortic Stenosis Management

Severe aortic stenosis (AS) affects 3.4% of the elderly over 60 years of age. It presents with exertional dyspnea, syncope, angina, and progression to irreversible congestive heart failure. Early intervention produces a better outcome in preventing the clinical deterioration of AS. The choice of intervention is transcatheter aortic valve implantation or surgical aortic valve replacement (SAVR). The decision should be made after evaluating an individual case based on its clinical features and the user’s experience with transcatheter aortic valve replacement (TAVR). We reviewed available data to illustrate the types of ASs, the background of interventions, current guidelines for TAVR, and its comparison with SAVR in terms of adverse effects.

Recent advances in aortic valve replacement

Aortic valve replacement has stood the test of time but is no longer an operation that is exclusively approached through a median sternotomy using only sutured prostheses. Currently, surgical aortic valve replacement can be performed through a number of minimally invasive approaches employing conventional mechanical or bioprostheses as well as sutureless valves. In either case, the direct surgical access allows inspection of the valve, complete excision of the diseased leaflets, and debridement of the annulus in a controlled and thorough manner under visual control. It can be employed to treat aortic valve pathologies of all natures and aetiologies. When compared with transcatheter valves in patients with a high or intermediate preoperative predictive risk, conventional surgery has not been shown to be inferior to transcatheter valve implants. As our understanding of sutureless valves and their applicability to minimally invasive surgery advances, the invasiveness and trauma of surgery can be reduced and outcomes can improve. This warrants further comparative trials comparing sutureless and transcatheter valves.

Review of minimal access versus transcatheter aortic valve replacement for patients with severe aortic stenosis

Transcatheter aortic valve replacement (TAVR) and minimally invasive aortic valve replacement (miniAVR) have become alternatives to surgical aortic valve replacement via median sternotomy (SAVR) to treat severe aortic stenosis (AS). Despite increased interest and utilization, few studies have directly compared TAVR and miniAVR. A review of the current literature shows TAVR to be an indispensable tool for inoperable, high-risk, and perhaps intermediate-risk patients with severe AS. However, it is associated with a number of deleterious perioperative outcomes, such as valvular regurgitation and vascular complications. MiniAVR is associated with decreased intensive care unit (ICU) and hospital length of stay, a lower incidence of blood transfusions, decreased ventilation time, and improved cosmetic results. MiniAVR maintains potential advantages over SAVR, including the implantation of a durable prosthesis and low rates of perioperative myocardial infarction and paravalvular leak. It is associated with longer aortic cross clamp and cardiopulmonary bypass (CPB) times; however, the use of sutureless valve implants can circumvent this. Studies comparing TAVR and miniAVR demonstrate decreased postoperative mortality, valvular regurgitation, and incidence of stroke in the miniAVR cohorts. Few studies currently exist comparing TAVR and miniAVR, as it is hard to compare the typically low-risk miniAVR versus high-risk TAVR patient populations. It is clear that both strategies will be cornerstones in the modern AVR era, but the situations in which to apply each strategy have not yet been clearly delineated. This highlights the need for surgeons to adopt these minimally invasive techniques. We believe there is a compelling role for miniAVR in low- and intermediate-risk patients, but due to the paucity of data, neither TAVR nor miniAVR should be discounted before a randomized, risk-stratified trial is performed. More studies are needed to compare TAVR and miniAVR in low- and intermediate-risk patients.