The Clinical Development of Percutaneous Heart Valve Technology

Transcatheter valve implantation for patients with aortic stenosis: a position statement from the European Association of Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

AIMS

To critically review the available transcatheter aortic valve implantation techniques and their results, as well as propose recommendations for their use and development.

METHODS AND RESULTS

A committee of experts including European Association of Cardio-Thoracic Surgery and European Society of Cardiology representatives met to reach a consensus based on the analysis of the available data obtained with transcatheter aortic valve implantation and their own experience. The evidence suggests that this technique is feasible and provides haemodynamic and clinical improvement for up to 2 years in patients with severe symptomatic aortic stenosis at high risk or with contraindications for surgery. Questions remain mainly concerning safety and long-term durability, which have to be assessed. Surgeons and cardiologists working as a team should select candidates, perform the procedure, and assess the results. Today, the use of this technique should be restricted to high-risk patients or those with contraindications for surgery. However, this may be extended to lower risk patients if the initial promise holds to be true after careful evaluation.

CONCLUSION

Transcatheter aortic valve implantation is a promising technique, which may offer an alternative to conventional surgery for high-risk patients with aortic stenosis. Today, careful evaluation is needed to avoid the risk of uncontrolled diffusion.

Future Directions in Degenerative Mitral Valve Repair

Mitral valve repair is by far the most common operation for degenerative mitral regurgitation. If the procedure is performed before left ventricular dysfunction occurs and atrial fibrillation develops, the operative risk is very low and life expectancy is super imposable to that of the sex- and age-matched population. Despite these achievements, there are areas that could still be improved. Progress in treating degenerative mitral regurgitation is expected to move along several directions. More precise diagnostic methods will be developed to reliably quantify mitral regurgitation and identify early irreversible ventricular and atrial changes. The refinement of surgical techniques and search for new, innovative solutions should never be abandoned. Finally, transcatheter correction of mitral regurgitation represents a new, emerging field of cardiovascular medicine and is expected to have a significant impact on the surgical practice in the future.

Real-time interactive MRI-guided cardiac surgery: aortic valve replacement using a direct apical approach

Minimally invasive cardiac surgery requires arresting and emptying of the heart, which compromises visualization of the surgical field. In this feasibility study a novel surgical procedure is demonstrated in which real-time MRI is used to guide the placement of a prosthetic aortic valve in the beating heart via direct apical access in eight porcine hearts. A clinical stentless bioprosthetic valve affixed to a platinum stent was compressed onto a balloon-tipped catheter. This was fed through a 15-18-mm delivery port inserted into the left ventricular (LV) apex via a minimally invasive subxyphoid incision. Using interactive real-time MRI, the surgeon implanted the prosthetic valve in the correct location at the aortic annulus within 90 s. In four of the animals immediately after implantation, ventricular function, blood flow through the valve, and myocardial perfusion were evaluated with MRI. MRI-guided beating-heart surgery may provide patients with a less morbid and more durable solution to structural heart disease.

Sutureless Stented Aortic Valve Implantation Under Direct Vision: Lessons From a Negative Experience in Sheep

BACKGROUND AND AIM OF THE STUDY

Percutaneous aortic valve replacement has been proposed as a valid alternative to surgery in selected cases; however, it still has many problems. As a less radical preliminary step, we implanted a balloon-expandable stented aortic valve under direct vision in sheep.

METHODS

Under cardiopulmonary bypass (CPB) and through a transverse aortotomy, an aortic valve mounted in a long tubular balloon-expandable stent was implanted in six acute sheep. The leaflets were not excised and no anchoring sutures were used between stent and native annulus. Epicardial, two-dimensional color Doppler echocardiography was used to assess the function of the stented valve followed by macroscopic inspection at necropsy.

RESULTS

Direct visualization of the entire annulus when the collapsed, valved stent was placed within the aortic root was difficult in all animals. Valve deployment took less than 1 minute. The surgical procedure resulted in major complications in all cases. Migration (3/6), paravalvular leak (2/6), mitral conflicts resulting in mitral regurgitation (1/6), and coronary ostia obstruction (2/6) were the major events at the origin of the failure. Only three animals could be weaned from CPB but did not recover enough to survive the procedure.

CONCLUSIONS

Sutureless implantation of a stented aortic valve through standard CPB and aortotomy is far more complex than expected. Changes in stent design and surgical approach are indicated.

[Percutaneous cardiac valve replacement: a review]

Surgery is no longer the only technique to replace a cardiac valve. New percutaneous procedures allow aortic or pulmonary valve implantation. Even if the feasibility of these procedures has been proved, cases reported are very rare and selected. This emergent technology is still at an early stage of development and new prospective studies will be necessary to evaluate these procedures correctly before concluding their clinical benefit. At this time surgery remains the gold standard in terms of cardiac valve replacement.

Surgery Insight: current advances in percutaneous heart valve replacement and repair

Several advances have been made in interventional cardiology, particularly in the field of valvular heart disease. Among the procedures for which technologies are available, percutaneous replacement of the pulmonary and aortic valves, and percutaneous repair of the mitral valve, via annuloplasty or the Alfieri method, are the best known. Along with the excitement generated by these new subspecialties, however, there has also been skepticism. In this article we focus on the current innovations that have been applied to the procedures in humans, and discuss the advantages and disadvantages of the different strategies.