The road to the ideal stent: A review of stent design optimisation methods, findings, and opportunities

Coronary stent designs have undergone significant transformations in geometry, materials, and drug elution coatings, contributing to the continuous improvement of stenting success over recent decades. However, the increasing use of percutaneous coronary intervention techniques on complex coronary artery disease anatomy continues to be a challenge and pushes the boundary to improve stent designs. Design optimisation techniques especially are a unique set of tools used to assess and balance competing design objectives, thus unlocking the capacity to maximise the performance of stents. This review provides a brief history of metallic and bioresorbable stent design evolution, before exploring the latest developments in performance metrics and design optimisation techniques in detail. This includes insights on different contemporary stent designs, structural and haemodynamic performance metrics, shape and topology representation, and optimisation along with the use of surrogates to deal with the underlying computationally expensive nature of the problem. Finally, an exploration of current key gaps and future possibilities is provided that includes hybrid optimisation of clinically relevant metrics, non-geometric variables such as material properties, and the possibility of personalised stenting devices.