A structure made of a zinc wire mesh that dissolves slowly in the vessel wall should be suitable for children and adults.
If the coronary vessels are dangerously narrowed, a heart attack may occur. With a stent, the constriction can be widened and stabilized. However, those affected have to take medication permanently in order to reduce the risk of thrombosis and vascular occlusion. A consortium of physicians and scientific researchers from the University Heart Centre Freiburg - Bad Krozingen (UHZ) is currently working with engineers to develop a stent made of the bioresorbable trace element zinc.
In contrast to materials used in the past, the material is not recognized by the body as a foreign body, is more visible, grows into the vessel wall faster than a conventional stent and is completely degraded within two years. This could eliminate the need for long-term medication.
"Zinc is used by the body as a trace element and is not perceived as a foreign body. Therefore, the body's rejection reaction - and thus the complication rate - is likely to be considerably lower than with conventional stents," said Prof. Dr. Christoph Hehrlein, head of the clinical study and senior physician at the Department of Cardiology and Angiology I at the UHZ.
The researchers and physicians at the UHZ had already investigated this in a study using an animal model, which was published in January 2019 in the scientific journal PLOS One. "We need new stents that have sufficient positioning power and are well tolerated by the body," said Dr. Christoph Bode, medical director of the Department of Cardiology and Angiology I at the UHZ.
As part of the BioZ-Drug Eluting Stent project, which is being carried out by the UHZ in cooperation with optimed GmbH from Ettlingen, Germany, the new stents will be tested in detail in preclinical trials. In the last leg of the project, a clinical pilot study will be carried out to find out for which patients the new stents are particularly suitable.
The newly developed stents could be a major step forward, particularly for children and adolescents with vascular problems. Because of vascular growth, classical implants made of non-degradable material such as cobalt-chromium will eventually become too small and have to be expanded in a hospital setting using x-ray fluoroscopy. "Since the new stents decompose completely over time, they do not impede the growth of the vessels. In the best-case scenario, the children are spared another intervention," said Hehrlein.