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| Clinic for Cardiology |
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25th October 2003
Keeping vessels open
The way into the heart:
In order to reach the heart, physicians usually use the arteries (red). The groin area is used as access in most cases. Pacemaker electrodes, on the other hand, are pushed up to the heart through the veins (blue).
The coronary arteries supply blood to the heart. If they are blocked, they can be dilated using a balloon pump. However, this is often not enough to keep them open permanently. “Following the intervention the dilated vascular walls sometimes spring back again”, Horstkotte explains. This is why cardiologists often opt for the insertion of a gridlike vascular support (a so-called stent) in the prepared arteries.
But the stent, considered to be one of the most significant breakthroughs in the field of cardiac medicine in the last decade, brings about a whole new problem. “It is a foreign body inside the artery”, says Horstkotte. “This can mean infection and unwanted growths.” In one fifth of patients treated, cells grow through the grid of the stent. Result: the coronary artery becomes blocked once more (restenosis).
Horstkotte is optimistic: “The problem of restenosis can be solved.” The heart specialists are partly hopeful due to new coated stents. They contain agents which should – in a variety of ways – prevent unwanted cell growth on the arterial walls. Already available: stents equipped with “sirolism”, a material which slows down cell growth. Studies have shown that sirolism stents considerably reduce the rate of restenosis – to between 2 and 7%.
Other stent agents are currently undergoing tests. “It is possible”, says the expert, “that anti-inflammatory substances could turn out to be better with regard to long-term effectiveness and tolerance”.
These coated stents could be particularly beneficial for diabetics and patients with kidney problems, who are at increased risk of developing restenosis.
Fig. bottom: Using a balloon catheter, blocked sections of the coronary arteries can be rendered passable. Usually a stent is then inserted.
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