Impact of stent size selection during a single stenting with kissing balloon inflation for left main bifurcation lesions.

Due to the substantial discrepancy in vessel diameter between the proximal and distal segments, appropriate stent size selection is important in percutaneous coronary intervention (PCI) of the left main bifurcation (LMB). Inadequate stent expansion in both the main trunk and daughter branches after kissing balloon inflation (KBI) may contribute to adverse clinical outcomes. We investigated the relationship between stent size selection and vessel dilation in the distal main vessel (DMV) and side branch (SB). We analyzed 80 cases of single stenting with KBI under optical coherence tomography (OCT) guidance for LMB at the Yamaguchi University Hospital and in the 3D-OCT bifurcation registry. Cases were divided into large and small size stent groups based on whether the stent size exceeded or fell below the average of the distal and proximal reference diameters (AvRD). The percentages of ostial stenosis (%OS) in the DMV and SB, along with incomplete stent apposition (ISA) at the bifurcation segment derived by OCT, were compared between the groups. The large size stent group exhibited better dilation in both the DMV and SB compared to the small size stent group (DMV%OS: 4.8 ± 9.3% vs. 9.7 ± 7.8%, P = 0.03; SB%OS: 14.4 ± 10.1% vs. 22.1 ± 12.3%, P = 0.004). There was no significant difference in the incidence of ISA at the bifurcation segment between the two groups (large size stent group:11.4 ± 9.2% vs. small size stent group:14.4 ± 15.7%, P = 0.29). Selecting a stent size larger than the AvRD may be associated with optimal ostium dilatation in both the DMV and SB of the LMB.