Percutaneous aortic valve replacement is becoming a reality and brings new hope for a number of patients who cannot currently be treated with traditional surgical techniques.
Whereas surgical valve replacement concerns about 200,000 patients worldwide every year, it is estimated that between 1/3 (Iung et al, Euro Heart Survey, 2003) and 2/3 (Rambas Pai, USC AHA 2004) of patients do not receive surgery due to either excessive risk factors and comorbidities or patient refusal due to fear of lifestyle changes following heavy surgery in elderly patients. The size of this untreated cohort is expected to increase, reflecting the aging population. However, without replacing the valve, the disease is associated with a very high mortality rate (50 to 60% at one year) beyond the onset of symptoms. The goal of the percutaneous valve is to bring a less invasive therapeutic solution for these patients.
The Cribier-Edwards Percutaneous valve (Edwards Lifesciences, Irvine, Cal, USA) is a bioprosthesis made of three leaflets of equine pericardium sutured to a balloon expandable stainless steel stent. After balloon predilatation of the native valve, this bioprosthesis is crimped over a balloon catheter, and advanced over a stiff guidewire through the vessels (either from the femoral vein –antegrade/transseptal approach- or the femoral artery –retrograde approach-) up to the diseased fibro-calcific native aortic valve, using regular cardiac catheterization techniques. The bioprosthesis is then released by balloon inflation at mid-part of the native valve. In our institution, the technique is performed under local anesthesia and light sedation.
In our experience, the procedure (which first case was performed in April 2002) remains under investigation and implantations are strictly restricted to compassionate cases in patients who have been formally declined by two cardiac surgeons due to severe associated comorbidities. We have enrolled 40 patients to date in two single centre feasibility studies (the I-REVIVE and the RECAST studies). Three patients have now reached two years of follow-up. The valve performance has been excellent and there has not been a single case of valve failure when the valve was successfully placed (80% of the cases). High mortality during follow-up has been related to non valvular causes, mainly the evolution of life-threatening comorbidities.