Branch ostial optimization treatment and optimized provisional t-stenting with polymeric bioresorbable scaffolds: Ex-vivo morphologic and hemodynamic examination

The optimal side-branch (SB) ostium treatment after provisional side-branch scaffolding remains a subject of debate in bioresorbable vascular scaffold (BVS) era. In this study, we evaluated a novel optimized provisional T-stenting technique (OPT) and assessed its feasibility by comparison with T and small protrusion technique (TAP). Two provisional SB scaffolding techniques (OPT, n = 5; TAP, n = 5) were performed using polymeric BVS in a bifurcated phantom. The sequential intermediate snuggling balloon dilation, also called ostial optimal technique, was added to OPT but not TAP to dilate the side-branch ostium while the final snuggling balloon dilation applied for both procedures. Microcomputed tomography (microCT) and optical coherence tomography (OCT) were performed to assess morphology, and computational fluid dynamics (CFD) was performed to assess hemodynamics in the scaffolded bifurcations. Compared with TAP in microCT analysis, OPT created shorter neo-carina length than TAP (0.34 ± 0.10 mm vs 1.02 ± 0.26 mm, P < .01), longer valgus struts length (2.49 ± 0.27 mm vs 1.78 ± 0.33 mm, P < .01) with larger MB ostial area (9.46 ± 0.04 mm(2) vs 8.34 ± 0.09 mm(2), P < .01). OCT found that OPT significantly decreased the struts mal-apposition (13.20 ± 0.16% vs 1.94 ± 0.54%, P < .01). CFD revealed that OPT generated more favorable flow pattern than TAP, as indicated by less percent (4.68 ± 1.40% vs 8.88 ± 1.21%, P < .01) of low wall shear stress (<0.4 Pa) along the lateral walls. By using BVSs for bifurcation intervention, the sequential intermediate snuggling balloon dilation is feasible for optimizing ostial SB and facilitating subsequent SB scaffolding. Results show OPT is better than TAP for bifurcated morphology and hemodynamics in this ex-vivo study.