Optimazition Of Culotte-based Stenting Techniques For Treatment Of Coronary Bifurcation Lesions

Background: Biodegradable scaffolds(BRS)simulation studies in vitro not only can optimize the clinical application,but also the need for a reliable quantitative method.Microscopic computed tomography(m CT)is the main method of in vitro study of scaffolds,but it is difficult to be accurately observed by X-ray for BRS.Therefore,how to achieve X-ray visualization and 3D reconstruction is the prerequisite for BRS in vitro simulation study.Objectives: This study was to investigate the feasibility of contrast-enhanced m CT detection original images of polymer BRS and 3D reconstruction,and determine the optimal imaging conditions.Methods: BRS was made in L-polylactic acid(PLLA)and implanted into the coronary bifurcation model,followed by five different treatments for the model sample to detect the optimal m CT imaging conditions for BRS: baseline treatment,filling the sample with physiological saline and immediately with m CT scanning;treatment of-1,-2,-3 and-4,the sample filled with contrast agent and then scan,corresponding to the contrast agent soaking time 0,1,2 and 3 hours.Results: Compared with the baseline,the contrast agent filled the sample and immediately scan with m CT can only distinguish between the vascular lumen and scaffolds(struts)interface and cannot distinguish between the vessel wall and scaffolds(struts)interface until the contrast agent soaking time is greater than 2 hours(treatment-3 and-4)MCT can completely distinguish the struts that is the highest vascular CT,vascular wall followed,the lowest struts.By setting the CT value of 10-15 HU as the cut point,the detection rates of the baseline group and the treatment-1,-2,-3 and-4 group were 1.23 ± 0.31%,1.65 ± 0.26% and 58.14 ± 12.84%,97.97 ± 1.43% and 98.90±0.38%,respectively,(treatment-3 VS treatment-2,p<0.01).At the same time,BRS high quality 3D image reconstruction success rates of the baseline and treatment of-1,-2,-3 and-4,were 1.23%,1.65%,58.14%,97.97% and 98.90%,respectively(treatment-3 contrast-2,p<0.01).Conclusion: It is technically feasible to perform BRS original image and 3D reconstruction with contrast enhancement m CT and soaking time of contrast agent for more than 2 h is necessary for complete separation of scaffold struts from the surrounding structures in the phantom samples.This study provides a reliable qualitative and quantitative analysis method for BRS in vitro.Background:Theculotte based stenting(CBS)by nonabsorbable metal drug-eluting stent(m DES)remains widely used clinically,while polymer bioresorbable scaffold(p BRS)has beenemerging as a milestone in percutaneouscoronary intervention(PCI)of coronary bifurcation lesions(CBLs).However,the optimal technique of CBSfamily is in debate.Also,it is unclear whether CBS techniques developed in the era of m DES is still effective with using p BRS.Objectives: Thisbench testing study was to assess morphological characteristics for further optimization of CBS as using m DES,and to explore feasibility of CBS as using p BRS.Methods: In the coronary bifurcation modelmade ofthe polyvalent chloride,3-CBS techniques,mini culotte(MC),DKmini-culotte(DKMC)and DK mono-ring-culotte(DKMRC),were simulated in vitrowith using m DES and p BRS,respectively.Micro-computed tomography(MCT)wasadopted to analyze the bifurcated morphological parameters,includingthe stent under-expansion(SUE),residual ostial stenosis(ROS)and stent cell distortion(SCD)and optical coherence tomograph(OCT)to analyze the strut mal-apposition rate(MAR).Results: Qualitative analysis showed that there were significantly higher rates of SUE in the stent-overlapped segment,ROS at the ostial side-branch,SCD in the bifurcated segment in MC than DKMC or DKMRC as using m DES,which of the parameters were similar as using p BRS regardless of no statistical analysis due to the fewer samples.Whatever used m DES or p BRS,quantitative analysis demonstrated there were more severities of SUE in the stent-overlapped segment,ROS at the ostial side-branch,SCD and MAR in the bifurcated segment in MC compared to DKMC or DKMRC.Additionally,there were no differences in the bifurcated morphological characteristics between DKMC and DKMRC except longer stent-overlapped segment with DKMC because of only single ring overlapped with DKMRC.Conclusions: In bench testing,whatever used m DES or p BRS,DKMC or DKMRC is superior to MC in the bifurcated stent morphologies,they may become the manstream techniiques for the treatment of CBLs.Background: Despite mini-culotte stenting(MC)has been recommended as the standard by European Bifurcation Club(EBC)for the treatment of coronary artery bifurcation lesions(CBLs),there are still inherent shortcomings associated with MC.As a novel culotte technique,DK mini-culotte stenting(DKMC)has been shown to be associated with good clinical outcomes,but there are no solid data to confirm whether DKMC is superior to MC in the treatment of true CBLs.Objective: This study aimed to compare the clinical outcomes between DKMC and MC in the treatment of patients with true CBLs in the clinical real world.Methods: In the retrospective observational cohort study,there were 180 consecutive patients with true CBLs(Medina type 1,1,1;1,0,1;0,1,1)included.All the eligible patients underwent coronary angiography and percutaneous coronary intervention(PCI)with two-stent techniques in our hospital,among whom 97 patients received DKMC treatment(DKMC group)and 83 patients treated by MC group.The primary clinical end point was the composed major adverse cardiovascular events(MACE),which included cardiac death,myocardial infarction,and target vessel/ lesion revascularization(TVR/TLR).The secondary end points were stent thrombosis,in-stent restenosis,and individual components of MACE.Results: Compared to MC group,the cumulative event rate of MACE(4.2% vs.7.4%,P=0.219)and TVR/TLR(2.2% vs.4.9%,p=0.164)in DKMC group was numerically lower regadless of no significant difference.MACE was mainly caused by TVR/TLR for the restenosis in side branch(4.9%).Quantitative coronary angiography analysis showed that late lumen loss(0.12±0.42 mm vs.0.22±0.39 mm,p=0.045),segmental diameter restenosis of side branch(17.56±10.23% vs.23.62±13.28%,p=0.032)were lower as compared with MC group.There were similar rate of binary restenosis in the parent main vessel(1.2% vs.2.9%)and the main branch(4.8% vs.5.9% in both groups with numerically lower rate of binary restenosis in the side branch in DKMC(6.2% vs.13.2%,p=0.141)irrespective of no significant diffenrences.Conclusion: DKMC was associated with less late lumen loss and restenosis in the side branch,numerically lower rate of cumulative MACE and TVR/TLR.DKMC is more effective to treat true CBLs as compared to MC but warranted to be further confiemed by a ramdamized clinical trial.