Expanding our understanding on stent expansion

Bifurcation coronary stenoses represent complex three-dimensional structures, in which the percutaneous coronary intervention (PCI) has to respect different diameters and angulations to achieve good results in all three involved vessel segments. Therefore, while bifurcation PCI is considered as a complex procedure for interventionalists, it is a substantial technical challenge for the tubular stent devices as well.

Finet’s law1, describing the correlation between the diameters of the proximal main branch, the distal main branch and the side branch, is the cornerstone of understanding bifurcation anatomy. It highlights the existing diameter discrepancies between the three branches, especially the distal and proximal main branches. This understanding has substantially shaped bifurcation PCI procedures, making the proximal optimisation technique (POT) probably the one and only inevitable step2, with large registry datasets confirming the associated favourable impact on clinical outcome3.

Accordingly, expansion capacity has become one of the most important “unique selling points” for drug-eluting stents, especially when targeting special indications in bifurcations or the left main stem, in which the diameter mismatch can be massive. This has to be tackled by proper overexpansion (i.e.,...