Sequential coronary bifurcation revascularization with the Xposition S™ self-apposing stent: a comparative fractal bench study.

ABSTRACT

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.