Update on Aortic Percutaneous Valve Replacement

In the last few years, there have been several advances in the percutaneous treatment of the valve pathology, both in adults and children. This has brought about a new line of investigation for the treatment of patients at high-surgical risk or surgical contraindication.

In 1992, Andersen et al published the first experience with a balloon expandable stent implanted in the descending aorta in pigs. This project had been abandoned for several years, but later on, in tests carried out on corpses (Cribier´s unreleased test), it was observed that it was not necessary to remove the aortic valve in order to implant a bioprosthesis and the distance between the coronary ostia and the aortic ring was 19mm, enough to implant a stent in the stenotic native valve.

In 2002, the Rouen team led by Professor Alain Cribier carried out the first experience in humans on a patient contraindicated to aortic valve replacement surgery (AVR) with severe asymptomatic aortic stenosis.

The bioprosthesis is designed and mounted on a three-valve bovine pericardium, with a 23mm diameter and a 14mm height, expanded with a 22mm balloon (Edwards Lifesciences, Irving, CA, USA) implanted in subcoronary position (FIGURE Nº 1A-D). At the same time, Dr Bonhoeffer´s team carries out the first bioprosthesis implant in pulmonary position, with a bioprosthesis designed with a portion of an 18mm internal jugular vein sutured to a vascular balloon expandable platinum stent and compatible with a 18f sheath (FIGURE Nº 2). The experience with this valve has grown and there are currently 59 patients published and according to the data shown in international meetings it amounts to 100 published cases.

Shortly after, there were several advances in aortic position, suggesting a self-expandable bioprosthesis (CoreValve) for the treatment of aortic disease (different to the bioprosthesis developed by Cribier). The potential advantage of a self-expandable bioprosthesis is that it shows perfect adaptability to the aorta and stenotic valve.
These two bioprostheses for the percutaneous treatment of aortic pathology are still being tested. The balloon expandable bioprosthesis can be implanted with both anterograde-transseptal and retrograde approach, with local anaesthesia.

At the moment, a Phase 1 protocol is being carried out to determine the safety and efficacy of the Edwards-Cribier bioprosthesis in Europe, Canada and US.

The CoreValve bioprosthesis is implanted by retrograde approach and requires general anaesthesia and extracorporeal circulation to allow the correct positioning of the bioprosthesis, although recent reports show the first cases of implantation without extracorporeal circulation.

Recently, J. Webb published the 6-month follow-up of the first bioprosthesis implantation by transapical approach, in seven symptomatic patients for severe aortic stenosis, non-eligible for AVR, surgical replacement or percutaneous replacement by femoral approach. All of them were successfully implanted, with a mortality rate at 30 days of 14% (non-cardiac cause). The improvement in the reported aortic valve area was of 0.7 ± 0.3 to 1.8 7± 0.7 cm2, with no complications related to the bioprosthesis during the follow-up.

The first experience in minimally invasive aortic valve replacement suggests that the transapical approach is possible in those patients that are non-eligible for AVR or surgical replacement due to unacceptable risk or in patients where the valve replacement by femoral approach is not possible.

Undoubtedly, the different lines of investigation in the field of valve replacement will allow new therapeutic options, opening up a new sub-speciality branch and perspectives for these valve patients.

« Back to News