Optical coherence tomography assessment of acute thrombogenicity at bifurcation sites using different stenting techniques: A porcine arteriovenous shunt study.

OBJECTIVES: We aimed to compare bare-metal stents (BMS), durable-polymer everolimus-eluting stents (DP-EES), and abluminal biodegradable-polymer sirolimus-eluting stents (ABP-SES) in the bifurcation model setup. BACKGROUND: The mechanism of thrombogenicity, which differs among second-generation stents implanted using double-kissing (DK) crush or culotte stenting techniques, remains unclear. We have shown previously that setting up a porcine arteriovenous shunt model is feasible and useful to assess thrombogenicity at vessel bifurcation points. METHODS: Six porcine shunt models were prepared for the comparison between DK crush and culotte stenting techniques using BMS, DP-EES, and ABP-SES. Intracoronary imaging with high-resolution optical coherence tomography (OCT) was performed to evaluate the thrombogenicity in different stent types in the bifurcation stenting model and was evaluated by a core lab. RESULTS: Culotte stenting demonstrated more thrombogenicity at the proximal main branch (MB) with DP-EES, side branch (SB) with BMS, and the bifurcation site irrespective of the stent type, while DK crush technique exhibited thrombogenicity only at SB with BMS and ABP-SES. OCT analysis revealed malapposition of DP-EES in the proximal MB with culotte stenting. Stent expansion was generally larger in ABP-SES than BMS and DP-EES. CONCLUSIONS: The study provides hypothesis-generating findings in distinct thrombogenicity of bifurcation stenting with DP- or ABP-coated drug-eluting stents.

Feasibility of a Porcine Arteriovenous Shunt Model for Assessment of Acute Thrombogenicity in Bifurcation Stenting Technique By Optical Coherence Tomography.

BACKGROUND: Double kissing (DK) crush stenting has been reported as a superior bifurcation stenting strategy compared to culotte stenting. However, the mechanism associated with the reduction of clinical events by DK crush stenting remains unclear. We therefore investigated the thrombogenicity of DK crush stenting and culotte stenting with both bare-metal stents (BMS) and drug-eluting stents (DES) and the feasibility of a novel porcine arteriovenous shunt model. METHODS: High-resolution intracoronary imaging with optical coherence tomography (OCT) evaluated the bifurcation stenting models for thrombogenicity. RESULTS: All porcine models retained continuous circulation without blood leakage. Thrombus was macroscopically demonstrated around the bifurcation in all settings. The volume of thrombus (mm3) with BMS using DK crush/culotte and DES using DK crush/culotte were 1.38/1.19 and 0.09/0.15, respectively. Culotte stenting had more thrombus in the proximal main branch, and DK crush stenting had more at the bifurcation. Unlike DK crush stenting, culotte stenting showed malapposition in the proximal main branch and bifurcation segments. CONCLUSION: The feasibility of a porcine arteriovenous shunt model to assess thrombogenicity by OCT in bifurcation stenting technique was confirmed. OCT detected less thrombogenicity in DES when used in the bifurcation model when compared to BMS.

Aortic valve ChromaFlo®: a feasibility study of aortic regurgitation and effective annular aortic area assessment in a porcine model.

Aortic valve annular complex was rediscovered after the introduction of transcatheter aortic valve replacement; and imaging has been crucial in determining the annular geometry. Although the procedure has evolved, complications related to the annular mechanical response following valve implantation, such as aortic insufficiency, still occur in practice. We documented the feasibility of invasive assessment of aortic valve annular complex and the detection of induced aortic insufficiency via intravascular ultrasound with ChromaFlo® technology in a porcine model.