Investigating the Equivalent Plastic Strain in a Variable Ring Length and Strut Width Thin-Strut Bioresorbable...

Area of Science:

• Biomaterials Engineering
• Medical Device Design
• Computational Mechanics

Background:

• Bioresorbable scaffolds (BRS) are advancing, with Arterius Ltd's ArterioSorb[Formula: see text] nearing clinical trials.
• Previous BRS generations faced brittle fracture during balloon angioplasty, risking patient safety.
• Optimizing BRS design is crucial to mitigate fracture and improve clinical performance.

Purpose of the Study:

• To investigate how varying ring length and strut width of the ArterioSorb[Formula: see text] BRS affect fracture resistance.
• To analyze the distribution of equivalent plastic strain in scaffold struts after expansion.
• To assess scaffold performance regarding side branch access, radial strength, deployed diameter, and recoil.

Main Methods:

• Utilized finite element analysis (FEA) to simulate crimping, expansion, and radial crushing of five scaffold designs.
• Employed Abaqus/Explicit for simulations, comparing in-silico predictions with in-vitro data for the open cell variant.
• Analyzed plastic strain distribution along defined paths on scaffold crowns and rings.

Main Results:

• FEA accurately predicted the final shape of the baseline scaffold design.
• Wide strut designs exhibited significantly higher equivalent plastic strain (up to 2.4x) and twisting/splaying, increasing fracture and vessel damage risks.
• The baseline scaffold design demonstrated tolerance to significant over-expansion, a key clinical advantage.

Conclusions:

• Narrow strut designs are predicted to provide optimal performance and potentially enhance patient outcomes for the ArterioSorb[Formula: see text] BRS.
• Further research is needed to refine material modeling for next-generation polymeric BRS.
• In-vitro tests suggest the ArterioSorb[Formula: see text] BRS can withstand greater over-expansion than initially expected.