Percutaneous valve replacement is a type of nonsurgical procedure in which a heart valve is replaced using a guide tube known as a catheter. The catheter is inserted into an artery in the groin and passed up into the heart until it reaches the diseased valve. A wire with a balloon on the end, on which a replacement valve is mounted, is passed through the catheter until the new valve is positioned over the old one. The balloon is inflated, opening up the new valve and securing it in place. Finally, the balloon is deflated and the catheter and wire are withdrawn leaving the new valve in position.
The first percutaneous valve replacement was carried out in France in 2002. This type of valve replacement allows a new valve to be implanted without the need for open heart surgery. The relatively new technique has been used to treat a condition known as aortic stenosis, in which the aortic valve is narrower than usual. This reduces the flow of blood from the heart into the major artery known as the aorta, which supplies oxygenated blood to most of the body. Chest pain, breathlessness, weakness and palpitations may result and valve repair or valve replacement may then be required.
When aortic stenosis is severe, valve repair surgery may not be appropriate. Aortic valve replacement may be the only treatment option with the potential to improve symptoms and increase patient survival. It is hoped that percutaneous valve replacement could provide this treatment for patients who are too ill to undergo open heart surgery. When percutaneous valve replacement is used to replace the aortic valve, the technique can also be referred to as transcatheter aortic valve implantation.
The preliminary results of one large randomized, controlled trial suggested that percutaneous valve replacement could be a suitable alternative to the standard nonsurgical treatment. This standard treatment consisted of drugs, patient monitoring and a repair procedure to widen the aortic valve with a balloon, known as valvuloplasty. One of the main valve repair complications associated with valvuloplasty in adults is the fact that the aortic valve tends to narrow again after treatment.
Patients in the trial who were not fit enough for conventional surgery, and who received treatment with percutaneous valve replacement rather than the standard treatment, had their risk of dying lowered by 20 percent. Future research results should enable doctors to compare the effectiveness of percutaneous valve replacement against that of open heart surgery to replace the aortic valve. This could result in percutaneous valve replacement becoming a standard, rather than an experimental, method of treating aortic stenosis.