Novel Magnetic Resonance-Compatible Coronary Stent
The Absorbable Magnesium-Alloy Stent
A 54-year-old male patient with known 2-vessel coronary artery disease and stable angina presented for elective percutaneous coronary intervention of a proximal right coronary artery stenosis (Figure 1). Previously, the patient had undergone intervention of mid-left anterior descending coronary artery stenosis by sirolimus-eluting stent implantation.
Within the scope of the first-in-human clinical trial (Clinical Performance and Angiographic Results of Coronary Stenting with Absorbable Metal Stents [PROGRESS-AMS]), the patient was treated by implantation of an absorbable metal stent (Biotronik; Figure 2). This novel stent consists of a magnesium-based alloy that provides mechanical properties comparable to those of conventional stainless steel stents. At the same time, the magnesium alloy allows controlled complete biodegradation (reabsorption) within approximately 2 months. Because of its composition of >90% magnesium, the stent is completely radiolucent and cannot be visualized by x-ray. This requires the use of intravascular ultrasound to evaluate the postinterventional stent expansion (Figure 3). However, because the stent also does not exert metallic artifacts, it has potential for noninvasive follow-up by MRI (Figure 4).
Dr Eggebrecht is the recipient of a research grant from the University Duisburg-Essen (IFORES 10+2).