In Poland the first new-generation coronary stents, which gradually dissolve in the patient's body, have been inserted. In a few years they will be most commonly used in the restoration of aortic patency.
One of the patients who underwent the surgery consisting of inserting of a biodegradable "spring" was a working 55-year-old man who was diagnosed with unstable angina. Thanks to inserting two stents of this type, the patient's blocked coronary arteries have been widened.
Small springs made of polymers
Stents in the form of a small spring have been used for many years during coronary angioplasty.
Inside the artery they function as a scaffolding which widens it and supports its walls. They are intended to prevent restenosis, that is the recurrence of arterial stenosis. However, the spring sometimes damages the artery, provokes inflammation and yet more stenosis of the blood vessel.
As claimed by Professor Adam Witkowski, the Head the Department of Interventional Cardiology and Angiology at the Warsaw Institute of Cardiology, polymer stents do not have this disadvantage, as, after being inserted they become biodegraded. The degradation starts as early as a couple of months after surgery, and in two years - when the vessel wall is healed and rebuilt - they dissolve completely. The only substances that are left are carbon dioxide and water, which are not harmful to the body.
Inserting stents which remain in the patient's body only as long as there is a risk of arterial restenosis has been the dream of generations of cardiologists. When this recurs, the blood flow into the cardiac muscle gets restricted, which causes acute chest pains during physical exercise or in times of high stress.
The procedure is more effective
According to Professor Witkowski, the new stents should increase the effectiveness of angioplasty procedures. They can also reduce the number of complications and shorten the time of application of antiplatelet drugs (they decrease platelet aggregation). Traditional stents - made of steel or cobalt-chromium alloy - require taking such drugs for at least one year from inserting them into the blood vessel.
Biodegradable stents can also reduce the volume of atherosclerotic plaque. Its breaking off is a direct cause of heart attacks. Blood clotting considerably narrows or blocks the vessel and causes myocardial ischaemia.
If those facts are confirmed, that would be another breakthrough in treating coronary heart disease with the application of angioplasty procedures.
Professor Krzysztof Rzeczuch, the Head of Laboratory of Hemodynamics, Centre for Heart Diseases at the 4th Military Clinical Hospital in Wrocław, who has been inserting biodegradable stents since 2013, claims that they are most useful in young people, people actively involved in sports, people suffering from diabetes and those who might await surgery soon.
In Professor Rzeczuch's opinion, in 6-7 years three quarters of patients undergoing coronary angioplasty will get biodegradable stents inserted.
It all started with balloon angioplasty
This is the fourth revolution in invasive cardiology. The first was the introduction of the so-called coronary balloon angioplasty in the late 1970s. It consists in widening the narrowed vessels with an expanding balloon, which is introduced into the coronary artery via catheter through the femoral artery.
In the 1980s additional metal stents were introduced into the point of stenosis, which were intended to prevent the vessel from sudden blocking. The procedure was not always successful. At the beginning of the 21st Century stents were covered with substances impeding the growth of the vessel wall.