Search

Coronary bifurcation revascularization needs to take account of the diameter differential between vessels and to limit side-branch obstruction (SBO). The self-apposing properties of the Xposition S™ stent (STENTYS, France) seem interesting in this regard. The present experimental fractal bench study determined the best provisional stenting technique using Xposition S™. Three sequential strategies were compared (n = 5/group): implantation alone, side-branch inflation (SBI), and re-POT (initial proximal optimization technique (POT) + SBI + final POT). 2D- and 3D-OCT analyses and micro-CT scan were performed to quantify the main mechanical results at each step. Of the three groups, SBI and re-POT provided better final results than implantation alone in terms of residual SBO (respectively, 24.6 ± 5.6% and 24.8 ± 5.0% vs. 46.5 ± 10.3%, p < 0.05) and malapposition (respectively, 0.9 ± 0.6% and 0.8 ± 0.4% vs. 3.8 ± 1.9%, p < 0.05). Unlike SBI, the two POTs of the re-POT sequence did not improve the final result. SBI, alone or as part of re-POT, systematically led to one connector breakage, whereas implantation alone maintained complete stent integrity (p < 0.05). In Xposition S™ implantation, SBI should be systematic, but not post-dilatation specifically dedicated to bifurcation stenting (i.e., POTs). However, global post-dilatation is still mandatory to prevent stent underexpansion due to untreated stenosis. [ABSTRACT FROM AUTHOR]

With the aim of assisting interventional cardiologists during decision making for revascularization, reduced-order (0D) approaches have been developed to predict the true fractional flow reserve (FFRTrue) of individual stenoses in multiple-lesion arrangements. In this study, a general equation was derived to predict the FFRTrue of a left main (LM) coronary stenosis with downstream lesions, one in the left anterior descending (LAD) and the other in the left circumflex (LCx) artery, and distinct collateral circulations supplying each daughter artery. An in vitro model mimicking the fractal nature of LM bifurcation trees with collateral branches was developed to validate the FFR values obtained with the prediction model (FFRPredModel). Our results demonstrated that: (1) considering collaterals significantly improved the FFRPredModel estimation for a moderate LM stenosis with two downstream lesions as compared to computations with no collateral consideration (p < 0.001): mean absolute error |FFRPredModel − FFRTrue| ± SD was equal to 0.02 ± 0.01 vs. 0.04 ± 0.02 respectively, and (2) Deviations from FFRTrue for LM stenoses are correlated to both, downstream lesion severities and collateral developments. The present study supports the hypothesis that collateral circulations supplying the LAD and LCx must be considered when predicting the FFRTrue of an LM stenosis with downstream lesions. [ABSTRACT FROM AUTHOR]