Impact of post-dilatation with a focal expanding balloon for optimization of intracoronary stenting.

Optimal stenting frequently requires additional stent post-dilatation following initial stent deployment. Stent post-dilatation using a focal expanding balloon (FB) that grows 0.5 mm larger centrally may achieve a larger final stent lumen with fewer stent edge injuries as compared to use of a conventional unidiameter balloon (UB). In the present prospective study, of 128 stented lesions in 122 patients, 63 lesions had stents dilated with FB (Group F), while 65 lesions had stents dilated with UB (Group U). All balloons for stent post-dilatation were half-sized up to reference diameter by on-line quantitative coronary analysis. There were no differences in the reference diameter, pre-procedural minimal lumen diameter (MLD), balloon/artery ratio, and final balloon pressure between the two groups. Post-procedural MLD in Group F was significantly larger than that in Group U (3.03 +/- 0.43 vs 2.80 +/- 0.47 mm, P < 0.001). Stent edge injury occurred in 4 patients, and stent thrombosis in 2 patients in Group U, but not in Group F. Minimal lumen diameter at 6 months in Group F was significantly larger than that in Group U (2.05 +/- 0.63 vs 1.82 +/- 0.66 mm, P < 0.05), and incidence of restenosis was significantly lower in Group F than Group U (9% vs 22%, P < 0.05). By using a focal expanding balloon for stent optimization, a larger stent lumen can be obtained safely, and subsequent incidence of restenosis can be reduced.