Mechanical properties of the drug‐eluting bioresorbable magnesium scaffold compared with polymeric scaffolds and a permanent metallic drug‐eluting stent

Abstract

Objectives: To compare on the bench the physical and mechanical properties of Magmaris, a magnesium bioresorbable scaffold (BRS), with Absorb and DESolve polymeric BRS and a permanent metallic stent. Background: Understanding the mechanical and physical properties of BRS is crucial for appropriate implantation and postdilatation. Methods: Testing was performed in fluid at 37 C and in silicone bifurcation phantoms with a 30 angle between main branch (MB) and side branch. Results: The 3.0-mm Magmaris BRS did not fracture after MB postdilatation up to 4.4 mm in contrast to the Absorb where the safe postdilatation diameter was 3.7 mm. For dilatation through stent cells, there were no Magmaris fractures with 3.0-mm noncompliant (NC) balloons inflated to nominal pressure. Mini-kissing balloon postdilatation with two 3.0-mm NC balloons up to 17 atm was without fracture except for an outlier. Longitudinal and radial strengths were similar for Magmaris and Absorb BRS. The crossing profile for the Magmaris was larger than other devices. Recoil 120 min after deployment was the greatest for Magmaris but 120 min after 3.5 mm postdilatation all devices had similar diameters. Conclusions: The Magmaris BRS was more resistant to strut fracture than Absorb. It had a larger crossing profile than other devices and similar radial and longitudinal strengths to Absorb. While recoil after deployment was greater with Magmaris, 120 min after 3.5 mm postdilatation all devices had similar diameters.

Long-term comparison of everolimus- vs. novolimus-eluting bioresorbable vascular scaffolds in real world patients

“…Reports regarding optical coherence tomography (OCT) and bench comparison of nBVS with eBVS showed that eBVS has fewer peaks per hoop (6 vs. 9), smaller vessel coverage (“footprint”; 27% vs. 30%), and higher radial strength than the nBVS (1.3 atm vs. 1.1 atm) while nBVS provided smaller residual area stenosis (20.1% vs. 14.9%; p < 0.01) and larger maximum (3.2 mm vs. 3.5 mm; p = 0.01) and minimum (2.7 mm vs. 2.9 mm; p < 0.01) scaffold diameters with no strut fracture, suggesting better expansion of the nBVS [ 12 , 13 ]. Another bench test comparing Magmaris (Biotronik AG, Bülach, Switzerland), Absorb and DESolve BVS showed that Absorb and Magmaris have larger recoil rates and only DESolve did not fracture during side branch dilatation and mini-kissing balloon postdilatation [ 14 ]. In our study, QCA analysis showed larger post-procedure minimum lumen diameter (MLD) in the nBVS group despite similar baseline angiographic RVD measured in both groups.…”

Characterization of a Sandwich PLGA-Gallic Acid-PLGA Coating on Mg Alloy ZK60 for Bioresorbable Coronary Artery Stents

“…Biodegradable magnesium (Mg) and its alloys are ideal candidates for stent platforms because they have less neointimal formation and provide long-term inhibition of the growth of smooth muscle cells (SMCs), unlike stainless steel [5,6]. The Mg alloys also have twice the tensile strength of unmodified biodegradable poly-l-lactide (PLLA), which leads to flexible stenting deployment and better radial force [7][8][9].…”

Acute Mechanical Performance of Magmaris vs. DESolve Bioresorbable Scaffolds in a Real-World Scenario

“…However, the dependency of expansion and eccentricity seems to be primarily a problem associated with the Absorb BVS ( 25 ) rather than the DESolve BRS ( 26 ). Barkholt et al ( 27 ) performed a bench evaluation of the mechanical properties of the Magmaris BRS and compared them with those of DES and PLLA-based BRS. They demonstrated that the Magmaris was more resistant to strut fracture than the Absorb BVS.…”