Kissing Balloon or Sequential Dilation of the Side Branch and Main Vessel for Provisional Stenting of Bifurcations : Lessons From Micro-Computed Tomography and Computational Simulations

ObjectivesThis study sought to evaluate post-dilation strategies in bifurcation stenting.BackgroundIn bifurcation stenting practice, it is still controversial how post-dilation should be performed and whether the kissing balloon (KB) technique is mandatory when only the main vessel (MV) receives a stent.MethodsA series of drug-eluting stents (DES) (n = 26) were deployed in a coronary bifurcation model following a provisional approach. After the deployment of the stent in the MV, post-dilation with the KB technique was compared with a 2-step, sequential post-dilation of the side branch (SB) and MV without kissing.ResultsThe percentage of the SB lumen area free of stent struts was similar after KB (79.1 ± 8.7%) and after the 2-step sequence (74.4 ± 11.6%, p = 0.25), a considerable improvement compared with MV stenting only without dilation of the stent at the SB ostium (30.8 ± 7.8%, p < 0.0001). The rate of strut malapposition in the ostium was 21.3 ± 9.2% after KB and 24.9 ± 10.4% after the 2-step sequence, respectively, a significant reduction compared with a simple SB dilation (55.3 ± 16.8%, p < 0.0001) or MV stenting only (47.0 ± 8.5%, p < 0.0005). KB created a significant elliptical overexpansion of the MV lumen, inducing higher stress concentration proximal to the SB. KB also led to a higher risk of incomplete stent apposition at the proximal stent edge (30.7 ± 26.4% vs. 2.8 ± 9.6% for 2-step, p = 0.0016).ConclusionsSequential 2-step post-dilation of the SB and MV may offer a simpler and more efficient alternative to final KB technique for provisional stenting of bifurcations.