Bifurcation Angle And Side Branch Rewiringpoint Affect The Bifurcatedstent Configurations Of DK-Crush Stenting: Insights From Bench Testing

Objects: This study sought to investigate the possible influence of different bifurcation angles and different side branch rewiring point on bifurcated stent configurations when using DK-crush technique.Methods:Virtual benchtestings were used to simulate procedures of DK-CRUSH technique on the bifurcated coronary model. Fifteen bifurcation models were divided into three groups according to the distal bifurcation angle(DBA):(1) Group 45°: n=3, DBA=45°;(2) Group 60°: n=9, DBA=60°;(3) Group 90°: n=3, DBA=90°. Furthermore, Group 60° were divided randomly into three groups according to the side branch rewiring point:(1) Group with low rewiring: n=3, the guidewire were then advanced through the most distal cellof the SB ostium;(2) Group with middle rewiring: n=3, the guidewire were then advanced through themiddle cellof the SB ostium;(3) Group with high rewiring:n=3, the guidewire were then advanced through the most proximal cellof the SB ostium.Aftervirtual stenting simulations were perfomed, changes of geometricalstentedconfigurations in the bifurcation region were quantified by the micro-computed tomographyscanning to assess theresults. Measurements includedthe side-branch ostium stenosis, the side-branch ostium coverage, the side-branch ostiumdeformation and the length of the carina.Results: Firstly, different bifurcation angles affect geometrical stentedconfigurationsin the bifurcation region. Compared with Group 45°, the length of the carina was much shorter in Group 90°(0.66±0.30 mm versus 1.72±0.32 mm, p<0.05). The minimum stent area was 4.81±0.36mm2 in Group 90° and 3.27±0.46mm2 in Group 45°(p<0.01). The residual area stenosis was 13.50±7.86% in Group 90° and 38.92±11.63% in Group 45°(p<0.01). Compared with Group 45°, the side-branch ostium deformation was significantly alleviated in Group 90°(DI: 0.23±0.09 vs 0.28±0.13, p<0.05). Difference was not statistically significant between Group 45° and Group 60° apart from the minimum stent area and the residual area stenosis.Secondly, different side branch rewiring point affect geometrical stented configurations in the bifurcation region. Compared with Group with high rewiring, the length of the carina was significantly shorter in Group with low rewiring and Group with middle rewiring(0.63 ± 0.28 mm versus 1.65 ± 0.30 mm, p<0.01; 1.10 ± 0.22 mm vs 1.65 ±0.30 mm, p<0.05). The minimum stent area and the residual area stenosis were significantly different between Group with low rewiring(4.81±0.36mm2 and 13.50±7.86%) and Group with high rewiring(3.27±0.46mm2 and 38.92±11.63%, p<0.01 and p<0.01, respectively). The minimum stent area and the residual area stenosis were also significantly different between Group with middle rewiring(4.61±0.53mm2 and 14.15±6.23%) and Group with high rewiring(3.27±0.46mm2 and 38.92±11.63%, p<0.05 and p<0.05, respectively). Compared with Group with high rewiring, the side-branch ostium deformation was significantly alleviated in Group with low rewiring and Group with middle rewiring(DI: 0.18±0.07 vs 0.28±0.13, p<0.05; 0.23±0.09 vs 0.28±0.13, p<0.05). Difference was not statistically significant between Group with low rewiring and Group with middle rewiring. But compared with Group with middle rewiring,we found more number of malapposed stent struts in the side branch ostium in Group with low rewiring.Conclusion: Different bifurcation angles and different side branch rewiring points impact the bifurcated stentconfigurations when using DK-CRUSH. The smaller bifurcation angle is, the longer length of the metal carina and theworse bifurcated stentconfigurationsof the side-branch ostium will be generated. A middle cell of the SB ostium may be the optimal choice when recrossing of the wire to the side branch.