双对吻挤压与经典挤压技术治疗冠状动脉分叉病变的前瞻性、随机、多中心研究

目的 比较双对吻挤压(DK crush)和经典挤压技术治疗冠状动脉分叉病变的临床效果.方法 311例真性分叉病变患者随机分入DK crush组(n=155)和经典挤压组(n=156),随访时间8个月.一级及二级终点分别为主要心脏不良事件(MACE,包括心肌梗死、心原性死亡和靶病变血运重建)和血管直径再狭窄及晚期丢失.结果 DK crush组糖尿病患者较多.经典挤压组及DKcrush组最终对吻扩张(FKBI)成功率分别为76%和100%(P＜0.001).DK crush术式的不足包括造影剂用量大(P=0.04)、球囊数量多(P＜0.01)、手术时间长(P＜0.001),但是对吻扩张不满意率显著减少(27.6%比6.3%,P＜0.01).临床随访率为100%,冠状动脉造影随访率为82%.经典挤压组累计再狭窄率为32.3%,而DK crush组为20.3%(P=0.01),经典挤压组分支血管再狭窄率高(24.4%比12.3%,P=0.01),而两组间主干血管再狭窄率差异无统计学意义.经典挤压组术后8个月时的累计MACE发生率为24.4%(FKBI失败组为35.9%,FKBI成功组为19.7%),显著高于DK crush组(11.4%,P=0.02).经典挤压组血栓栓塞率为3.2%(FKBI失败组为5.1%,FKBI成功组为1.7%),而DK crush组为1.3%(P＞0.05).经典挤压组术后8个月时无靶病变血运重建生存率为75.4%(FKBI失败组为71.2%,FKBI成功组为77.6%),而DK crush组为89.5%(P=0.002).结论 DK crush可能是治疗冠状动脉分叉病变的较佳术式.     

The Acute Changes of Fractional Flow Reserve in DK (Double Kissing), Crush,and 1‐Stent Technique for True Bifurcation Lesions

Background: While many studies confirmed the importance of fractional flow reserve (FFR) in guiding complex percutaneous coronary interventions (PCI), data regarding the significance of FFR for bifurcation lesions are still lacking. Methods: Between October 2008 and October 2009, 51 patients with true bifurcation lesions were consecutively enrolled and randomized into double kissing (DK) crush (n = 25), and provisional 1‐stent (n = 26) groups. FFR measurements at baseline and hyperemia were measured at pre‐PCI, post‐PCI, and at 8‐month follow‐up. Results: Clinical follow‐ups were available in 100% of patients while only 33% of patients underwent angiographic follow‐up. Baseline clinical and angiographic characteristics were matched between the 2 groups. Pre‐PCI FFR of the main branch (MB) in the DK group was 0.76 ± 0.15, which was significantly lower than in the provisional 1‐stent group (0.83 ± 0.10, P = 0.029). This difference disappeared after the PCI procedure (0.92 ± 0.04 vs. 0.92 ± 0.05, P = 0.58). There were no significant differences in terms of baseline, angiographic, procedural indexes, and FFR of side branch (SB) between the 2 treatment arms. However, immediately after PCI, the patient with DK crush had higher FFR in the SB as compared to the provisional 1‐stent group (0.94 ± 0.03 vs. 0.90 ± 0.08, P = 0.028, respectively) and also they had lower diameter stenosis (8.59 ± 6.41% vs. 15.62 ± 11.69%, P = 0.015, respectively). Conclusion: In the acute phase, immediately after PCI for bifurcation lesion, DK crush stenting was associated with higher FFR and lower residual diameter stenosis in the SB, as compared with the provisional 1‐stent group. (J Interven Cardiol 2010;23:341–345)     

Analysis of left main coronary artery bifurcation lesions treated with biolimus‐eluting DEVAX AXXESS plus nitinol self‐expanding stent: Intravascular ultrasound results of the AXXENT trial

Objective: To assess the efficacy of the AXXESS stent on the treatment of left main coronary artery (LMCA) bifurcation lesions using IVUS. Background: The treatment of LMCA bifurcation lesions remains challenging even with the use of drug‐eluting stents. The AXXESS system is a biolimus A9‐eluting self‐expanding stent, dedicated to the treatment of bifurcation lesions. Methods: Data were obtained from the AXXENT trial, a prospective, single‐arm, multicenter study designed to evaluate the efficacy of the AXXESS stent on the treatment of LMCA bifurcation lesions. IVUS was available in 26 cases at 6‐months follow‐up. Volumetric and cross‐sectional analyses within the AXXESS stent, and cross‐sectional analyses at the ostia of left anterior descending (LAD) and left circumflex coronary arteries (LCX) were performed. Results: Within the AXXESS stent, percent neointimal volume obstruction was (3.0 ± 4.1)% with a minimal lumen area of 10.3 ± 2.6 mm². AXXESS stent volume showed an 12.4% increase at follow‐up compared with postprocedure (P = 0.04). Lumen area was significantly smaller in the LCX ostium compared with the LAD ostium at follow‐up (3.6 ± 1.3 mm² vs. 5.5 ± 2.0 mm², P = 0.0112). There was greater neointimal formation in the LCX ostium compared with the LAD ostium (1.37 ± 1.20 mm² vs. 0.30 ± 0.36 mm², P = 0.0003). Conclusions: The AXXESS stent in the LMCA showed enlargement through 6‐months follow‐up and significant neointimal suppression. Greater neointimal formation and relatively inadequate stent expansion may contribute to luminal narrowing in the LCX ostium. © 2008 Wiley‐Liss, Inc.     

Three‐year outcome of drug‐eluting stent implantation for coronary artery bifurcation lesions

Objectives: To compare the very long‐term clinical outcomes of bifurcation lesions using the crush and the simultaneous kissing stent (SKS) techniques. Background: A variety of two‐stent techniques have been used to treat coronary artery bifurcation lesions in the drug‐eluting stent era, but the long‐term clinical outcome of these approaches is not known. Methods: A total of 74 consecutive patients underwent bifurcation stenting using either the crush or SKS techniques. Mean patient age was 66.91 ± 11.3 years; 26% were diabetic, and the left anterior descending/diagonal bifurcation was the most frequently treated lesion (68%). Results: In‐hospital outcomes were not significantly different between groups. Over a median follow‐up of 3.3 years, 1 patient in the SKS group and 3 patients in the crush group died (P = ns). Probable stent thrombosis leading to death according to the Academic Research Consortium definition occurred in 1 patient in the crush group. Mortality in the remaining 3 patients was noncardiac. Target lesion revascularization (TLR) occurred in 14 patients (40%) in the SKS group and 5 patients (12.8%) in the crush group (P = 0.015). Survival free from major adverse cardiac events (MACE) was significantly less in the SKS group and predominantly driven by TLR (60 vs. 88%, P = 0.001). Conclusions: In conclusion, over a median of 3.3 years of follow‐up, TLR and MACE are significantly lower in bifurcation lesions treated with the crush technique when compared with the SKS technique. Definite or probable stent thrombosis is rare with either technique. © 2009 Wiley‐Liss, Inc.     

Examination of Stent Deformation and Gap Formation after Complex Stenting of Left Main Coronary Artery Bifurcations Using Microfocus Computed Tomography

Background: Fluoroscopy and intravascular ultrasound (IVUS) lack sufficient resolution for assessing the results of complex stenting in true bifurcation lesions.
Objectives: After diverse bifurcation stenting at the left main coronary artery (LM) bifurcation model, the results were examined using microfocus computed tomography (MFCT).
Methods: The strut distribution of three kinds of stents deployed on a straight vessel segment was investigated. Classical crush, double kissing (DK)–double crush, and culotte stenting were performed on a three-dimensional (3D) LM model. The results were assessed using cross-sectional, longitudinal, and 3D reconstruction views of MFCT.
Results: Nonuniform strut distribution was observed in a corrugated stent design deployed on a straight vessel segment. Following classical crush stenting, a relatively large gap at the nonmyocardial site was observed in the corrugated stents. When the guidewire recrossed outside the ostium of the crushed side branch stent, kissing balloon inflation caused further crushing of the stent at the more distal segment. The dilated strut rose up from the main vessel bed after the first kissing balloon inflation in DK crush stenting; the advantage of DK would be cancelled after main vessel stenting due to recrushing the raised strut. The culotte stenting with closed-cell stents showed the restriction of the expansion at the branch ostium when it was dilated with a 3.5-mm balloon. The culotte stenting with open-cell-based stents showed a good stent apposition except for a tiny gap and small metallic carina at the distal bifurcation.
Conclusion: MFCT analysis in the 3D phantom model is useful to assess the structural deformation of the stents and gap on vessel wall coverage after complex stenting at the LM bifurcation.     

Twenty-Four-Month Update on Double-Kissing Crush Stenting of Bifurcation Lesions

A group of 312 patients who underwent percutaneous coronary intervention for bifurcation lesions at 12 centers in China, Singapore, Thailand, Israel, India, and Japan were enrolled in a prospective, randomized DKCRUSH-1 trial. The goal of the study was to compare the double kissing (DK) crush technique with the classical crush stenting technique. This study was carried out to determine the differences in the rates of final kissing balloon inflations (FKBI) and the long-term clinical outcomes. The 8-month results of the DKCRUSH-1 study have been previously reported. Here, we present several subgroups analysis and a 24-month clinical update. The results confirmed a sustained, lower MACE rate at 24 months with the double kissing (DK) crush stenting technique compared with that for the classical crush stenting technique (18.1% vs. 29.9%, p = 0.044).     

Crush Stenting With Drug‐Eluting Stents: Relevance of Coronary Bifurcation Lesion Location on Angiographic and Clinical Outcomes

Background

Data on the relevance of the location of coronary bifurcation lesions treated by crush stenting with outcomes were limited.

Hypothesis

We hypothesized that the location of the bifurcation lesion correlated with clinical outcome.

Method

A total of 212 patients with 230 true bifurcation lesions treated by crush stenting with drug‐eluting stents (DES) were assessed prospectively. Surveillance quantitative angiographies were indexed at 8 months after procedure. Primary endpoint was major adverse cardiac events (MACE), defined as cardiac death, myocardial infarction, and target lesion revascularization (TLR).

Results

Patients in the distal right coronary artery (RCAd) group were characterized by higher proportions of prior myocardial infarction and very tortuous lesions. However, lesions in the RCAd group, compared to those of other groups, had the lowest late lumen loss, with resultant lowest incidence of MACE at a mean follow‐up of 268±35 days. Independent predictors of MACE included unsatisfied kissing (KUS; hazard ratio [HR]: 12.14, 95% confidence interval [CI]: 4.01–12.10, P = .001) and non‐RCA lesion (HR: 20.69, 95% CI: 5.05–22.38, P = .001), while those of TLR were KUS (HR: 10.21, 95% CI: 0.01–0.34, P = .002), bifurcation angle (HR: 4.728, 95% CI: 2.541–4.109, P = .001), and non‐RCA lesion (HR: 16.05, 95%CI: 1.01–4.83, P = .001).

Conclusions

Classical crush stenting with drug‐eluting stents is associated with significantly better outcomes in RCAd. Quality of kissing inflation is mandatory to improve outcome. Copyright © 2009 Wiley Periodicals, Inc.     

Progressive vascular remodeling and reduced neointimal formation after placement of a thermoelastic self-expanding nitinol stent in an experimental model

Despite the improvements afforded by intracoronary stenting, restenosis remains a significant problem. The optimal physical properties of a stent have not been defined. We compared the vascular response to a thermoelastic self-expanding nitinol stent with a balloon-expandable tubular slotted stainless steel stent in normal porcine coronary arteries. Twenty-two stents (11 nitinol and 11 tubular slotted) were implanted in 11 miniature swine. The nitinol stents were deployed using the intrinsic thermal properties of the metal, without adjunctive balloon dilation. The tubular slotted stents were implanted using a noncompliant balloon with a mean inflation pressure of 12 atm. Intravascular ultrasound (IVUS) and histology were used to evaluate the vascular response to the stents. The mean cross-sectional area (CSA) of the nitinol stents (mm²) as measured by IVUS increased from 8.13 ± 1.09 at implant to 9.10 ± 0.99 after 28 days (P = 0.038), while the mean CSA of the tubular slotted stents was unchanged (7.84 ± 1.39 mm² vs. 7.10 ± 1.07 mm², P = 0.25). On histology at 3 days, the tubular slotted stents had more inflammatory cells adjacent to the stent wires (5.7 ± 1.5 cells/0.1 mm²) than the nitinol (3.9 ± 1.3 cells/0.1 mm², P = 0.016). The tubular slotted also had increased thrombus thickness (83 ± 85 μ) than the nitinol stents (43 ± 25 μ, P = 0.0014). After 28 days, the vessel injury score was similar for the nitinol (0.6 ± 0.3) and the tubular slotted (0.5 ± 0.1, P = 0.73) designs. The mean neointimal area (0.97 ± 0.46 mm² vs. 1.96 ± 0.34 mm², P = 0.002) and percent area stenosis (15 ± 7 vs. 33 ± 7, P = 0.003) were significantly lower in the nitinol than in the tubular slotted stents, respectively. We conclude that a thermoelastic nitinol stent exerts a more favorable effect on vascular remodeling, with less neointimal formation, than a balloon-expandable design. Progressive intrinsic stent expansion after implant does not appear to stimulate neointimal formation and, therefore, may provide a mechanical solution to prevent in-stent restenosis. Cathet. Cardiovasc. Diagn. 44:193–201, 1998. © 1998 Wiley-Liss, Inc.     

Intravascular ultrasound and 3D angle measurements of coronary bifurcations

Objective: To standardize the intravascular ultrasound (IVUS) analysis of coronary bifurcations. Background: Percutaneous treatment of bifurcation lesions is difficult particularly at the side branch ostium. Imaging techniques may improve our understanding of treatment options. There is no established IVUS methodology to assess the bifurcation. The present study aims to develop standards for bifurcation imaging. Methods: Quantitative IVUS analysis and 3D bifurcation angle measurements were performed in 34 patients who were selected from the Washington Hospital Center Database. Patients were included if both left anterior descending (LAD) and first diagonal (DX) pullbacks in the same procedure were done. Angiograms were available in 27 patients to measure the 3D bifurcation angle using specialized software. Pullbacks were analyzed proximal and distal to the bifurcation, and at the bifurcation. Results: Prox_LAD versus Prox_LAD(DX) were similar for vessel area (15.5 ± 4.6 mm² vs. 15.9 ± 4.0 mm², P = 0.19), lumen area (8.3 ± 3.6 mm² vs. 8.6 ± 3.3 mm², P = 0.25), and plaque area (7.2 ± 2.0 mm² vs. 7.3 ± 1.9 mm², P = 0.55). However, Bifurcation_LAD was larger than Bifurcation_DX for vessel area (17.3 ± 4.0 mm² vs. 16.6 ± 3.9 mm², P = 0.0083). The 3D angiographic bifurcation angle was 50° ± 13° (range of 26°–84°), and did not affect the IVUS measurements. IVUS analysis showed that bifurcation lesions did obey Murray's Law, as Prox_LAD lumen area measured 36.7 ± 25.1 mm³ versus Dist_LAD/Dist_DX measured 38.0 ± 29.1 mm³, P = 0.56. Conclusions: Two IVUS pullbacks should be performed for a complete assessment of the bifurcation and comparison with Murray's Law. The proposed IVUS analysis was not influenced by the bifurcation angle. © 2009 Wiley‐Liss, Inc.     

Impact of stent deformity induced by the kissing balloon technique for bifurcating lesions on in‐stent restenosis after coronary intervention

Objectives

To investigate the impact of stent deformity induced by final kissing balloon technique (KBT) for coronary bifurcation lesions on in‐stent restenosis (ISR).

Background

In experimental models, the detrimental effects of KBT have been clearly demonstrated, but few data exists regarding the impact of proximal stent deformity induced by KBT on clinical outcomes.

Methods

We examined 370 coronary lesions where intravascular ultrasound (IVUS)‐guided second‐generation drug‐eluting stent (DES) implantation for coronary bifurcation lesions was performed. Based on IVUS analysis, the stent symmetry index (minimum/maximum stent diameter) and stent overstretch index (the mean of stent diameter/the mean of reference diameter) were calculated in the proximal main vessel.

Results

The stent symmetry index was significantly lower (0.75 ± 0.07 vs 0.88 ± 0.06, P < 0.0001) and the stent overstretch index was significantly higher (1.04 ± 0.08 vs 1.01 ± 0.06, P = 0.0007) in lesions with KBT (n = 174) compared to those without KBT (n = 196). The number of two‐stent technique in lesions with KBT was 31 (18%). In multivariate analysis, the degree of stent deformity indices was not associated with ISR in lesions with KBT; however, two‐stent technique use was the only independent predictor of ISR at 8 months (hazard ratio: 3.96, 95% confidence interval: 1.25‐12.5, P = 0.01).

Conclusions

Second‐generation DES deformity induced by KBT was not associated with mid‐term ISR.

     

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

BackgroundDouble 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.MethodsHigh-resolution intracoronary imaging with optical coherence tomography (OCT) evaluated the bifurcation stenting models for thrombogenicity.ResultsAll 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.ConclusionThe 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.     

Immediate results of bifurcational stenting assessed with optical coherence tomography

Background : A tubular stent may adapt with difficulty to coronary bifurcation lesions (CBLs). Methods : Time domain or frequency domain (FD) optical coherence tomography (OCT) was performed to assess strut apposition immediately after stent implantation across four segments inside the bifurcation, in a consecutive series of patients. OCT pullbacks were performed in the main vessel (MV). Results : A total of 13,142 struts in 45 CBL in 41 patients were assessed. Strut malapposition was significantly more frequent in the half bifurcation facing the side‐branch (SB) ostium (42.9%) than in the proximal segment of the bifurcation 11.8%, half bifurcation opposite the SB 6.7%, or the distal segment 5.7% (all P < 0.0001). Lesions (n = 15) treated with stenting of both MV and SB had a total higher rate of malapposition than those (n = 30) treated with stenting of the MV only (17.6% vs. 9.5%; P = 0.0014). In latter group, lesions treated with FD‐OCT‐guided stent implantation (n = 13) presented a lower rate of malapposition than those treated with conventional angiographic‐guided stent implantation (n = 17) (7.1% vs. 17.5%; P = 0.005). Conclusions : In CBL, strut malapposition is particularly high at the SB ostium. However, a strategy of stenting MV only with adjunctive FD‐OCT guidance is associated with lower rates of malapposition. © 2012 Wiley Periodicals, Inc.     

IVUS radiofrequency analysis in the evaluation of the polymeric struts of the bioabsorbable everolimus‐eluting device during the bioabsorption process

Background : In the ABSORB study cohort A the changes in the amount of dense calcium and necrotic core have not been reported in comparison to the prestenting phase; this evaluation could be useful to better clarify the bioabsorption process. Aim of this study was therefore to evaluate the dynamic changes in plaque size and plaque tissue composition observed between 6 months and 2 years follow‐up, and to compare these findings to the prestenting phase. Methods : Angiography, intravascular ultrasound and derived parameters (virtual histology, palpography, and echogenicity) were serially assessed postprocedure, at 6 months and at 2 years in 20 patients. In a subset of 8 patients the same measurements were also recorded in the prestenting phase. Results : In the total population a reduction of 18% in the plaque area was observed between 6 month and 2 year follow‐up (7.56 ± 2.32 mm² at 6 months vs. 6.16 ± 2.10 mm² at 2 year follow‐up; P < 0.01). In the subgroup of eight patients who underwent IVUS during the pre‐stenting phase, the plaque area at 2 year follow‐up was not significantly different when compared to the prestenting plaque area (7.29 ± 2.29 mm² at prestenting vs. 7.48 ± 1.45 mm² at 2 year follow‐up, P = NS). Necrotic core area was reduced by 24% between the 6 month and 2 year follow‐up (0.97 ± 0.66 mm² at 6 months vs. 0.74 ± 0.53 mm² at 2 year follow‐up; P = NS), whilst dense calcium was reduced by 14% from 6 month to 2 year follow‐up (0.83 ± 0.50 mm² at 6 months vs 0.72 ± 0.64 mm² at 2 year follow‐up; P = NS). Whilst the necrotic core at 2 years follow‐up was not significantly different when compared to the pre‐stenting phase (0.62 ± 0.42 mm² prestenting vs 1.07 ± 0.56 mm² at 2 year follow‐up; P = NS), the area of dense calcium was significantly higher at follow‐up compared to prestenting (0.35 ± 0.35 mm² pre‐stenting vs. 0.84 ± 0.66 mm² at 2 year follow‐up; P < 0.05). Conclusions : The reduction in the necrotic core component between 6 month and two year follow‐up could be related to a synergistic effect of the bio‐absorption process and the anti‐inflammatory action of everolimus. © 2010 Wiley‐Liss, Inc.     

Impact of Diabetes Mellitus on Intravascular Ultrasound‐Guided Provisional Stenting in Coronary Bifurcation Lesions J‐REVERSE Sub‐Study

Objective

To investigate the impact of diabetes mellitus (DM) on provisional coronary bifurcation stenting under the complete guidance of intravascular‐ultrasound (IVUS).

Background

The efficacy of such intervention has not yet been fully elucidated in the DM patients.

Methods

A total of 100 DM and 139 non‐DM patients in a prospective multi‐center registry of IVUS‐guided bifurcation stenting were compared in angiographic results at 9 months. Vessel and luminal changes during the intervention were analyzed using the IVUS. Vascular healing at the follow‐up was also investigated in 23 lesions in each group using optical coherence tomography (OCT).

Results

No difference was detected regarding baseline reference vessel diameter and minimum lumen diameter in proximal main vessel (MV), distal MV, and side branch (SB). The rate of everolimus‐eluting stent use (78.4% vs. 78.3%), final kissing inflation (60.1% vs. 49.0%), and conversion to 2‐stent strategy (2.9% vs. 2.8%) were also similar. In the DM group, late loss was greater in proximal MV (DM 0.23 ± 0.29 vs. non‐DM 0.16 ± 0.24 mm, P < 0.05) and SB (0.04 ± 0.49 vs. ?0.08 ± 0.35 mm, P < 0.05). Smaller vessel area restricted stent expansion in the proximal MV (6.18 ± 1.67 vs. 6.72 ± 2.07 mm², P < 0.05). More inhomogeneous neointimal coverage (unevenness score, 1.90 ± 0.33 vs. 1.72 ± 0.29, P < 0.05) and more frequent thrombus attachment (26% vs. 4%, P < 0.05) were documented in the proximal MV at 9‐month follow‐up OCT.

Conclusions

Despite IVUS optimization for coronary bifurcation, DM is potentially associated with smaller luminal gain, higher late‐loss, and inhomogeneous vascular healing with frequent thrombus attachment in the proximal MV.

     

Temporary arterial stenting: Comparison to permanent stenting and conventional balloon injury in a rabbit carotid artery model

The objective was to assess the arterial wall response to temporary stenting with a removable nitinol stent in comparison with permanent stenting and balloon injury at 28 days in the rabbit carotid artery. Restenosis remains an important limiting factor after the implantation of permanent metallic stents and balloon angioplasty. We have developed a temporary nitinol stent that uses a bolus injection of warmed saline to collapse the stent for percutaneous removal. Vascular changes related to the thermal saline bolus injection required to remove a nitinol implanted stent were assessed in 12 rabbit carotid arteries at 7 and 28 days postinjection. Nitinol stents, inflated to 3.0 mm diameter, were implanted for 3 days (n = 6) and histology and quantitative histomorphometry examined at 28 days. Results were compared with permanently implanted stents (n = 5) and balloon injury (n = 9). Dual bolus injection of 10 ml at 70°C created an acute necrotizing injury and chronic neointimal proliferation, whereas injections of 5 ml at 63°C were minimally injurious. Temporary stenting resulted in the least neointimal proliferation measured by the intima to media ratio (0.22 ± 0.10 vs. 1.59 ± 0.31 for permanent stenting and; 0.49 ± 0.14 for balloon injury; P < 0.001). Temporary stenting maintained a significantly larger lumen than balloon (1.53 ± 0.72 mm² vs. 0.64 ± 0.14 mm²; P < 0.001), which could not be explained by absolute changes in intimal cross sectional area (0.14 ± 0.07 mm² vs. 0.21 ± 0.06 mm² respectively; P = 0.33). Temporary stenting resulted in a relatively larger vessel area within the external elastic lamina than with balloon (2.28 ± 1.06 mm² vs. 1.30 ± 0.18 mm²; P = 0.007). The thermal stent recovery process can create necrotizing vascular injury and neointimal proliferation at higher temperatures and injectate volumes. Stent removal after 3 days using 63°C saline bolus injection results in less neointimal proliferation than with permanent stents or balloon injury. In comparison to balloon injury, temporary stenting also may have a long-lasting beneficial effect on vessel recoil and remodeling, resulting in larger lumen size after stent removal. Cathet. Cardiovasc. Diagn. 41:85–92, 1997. © 1997 Wiley-Liss, Inc.     

Angiographic and Clinical Outcomes after Implantation of Drug Eluting Stents in Bifurcation Lesions with Crush or Kissing Stent Technique

Background

Long‐term outcome after bifurcation stenting with drug‐eluting stents (DES) for obstructive coronary artery disease is poorly understood. In this study, we report 6–9‐month angiographic follow‐up and long‐term clinical outcomes after implantation of drug‐eluting stents by crush and kissing stent technique for coronary bifurcation lesions.

Methods

Consecutive patients undergoing bifurcation stenting with DES by crush or kissing stent technique were enrolled in a prospective registry. Angiographic follow‐up was obtained at 6–9 months and clinical follow‐up completed for a median of 38 months.

Results

A total of 86 patients participated in the study. Bifurcation stenting by crush technique was performed in 73 (85%) and by kissing stent in 13 (15%) patients. Stenting of left main bifurcation was applied in 24 (28%) patients. Angiographic follow‐up was completed in 75 (87%) patients and showed restenosis in the main for 8 (11%) and side branch for 20 (27%) patients. Clinical follow‐up was available for a median duration of 38 months. During follow‐up, 2 (2%) patients died, 4 (5%) experienced myocardial infarction (MI), and 11 (13%) underwent target vessel revascularization (TVR) with an overall major adverse cardiac event (MACE) rate of 16%. In left main cohort, angiographic restenosis occurred in 9 (37%) patients, and 3 (12%) patients required TVR. There were no deaths or stent thrombosis. A comparison of crush and kissing stent technique showed significantly higher angiographic restenosis with crush (26% vs 13% in kissing stent patients, P = 0.046) and 95% of restenosis in crush group involved ostium of the side branch. There was no difference in clinical outcomes between the crush and kissing stent groups. Final kissing balloon dilatation (FKB) was successful in 65 (89%) patients in the crush group and associated with a significant reduction in MACE (8% in FKB successful vs 37% in FKB unsuccessful, P = 0.04) during follow‐up.

Conclusion

Bifurcation stenting with crush or kissing stent technique is safe and associated with a low rate of TLR and MACE on long‐term follow‐up. Crush stenting is associated with a significantly higher rate of side branch restenosis compared to kissing stent technique. FKB is associated with significant reduction in MACE during follow‐up. (J Interven Cardiol 2013;26:145–152)

     

Coronary plaque morphology affects stent deployment: Assessment by intracoronary ultrasound

The purpose of this study was to evaluate the changes in arterial wall morphology induced by coronary stent implantation and the influence of plaque morphology on stent expansion by intravascular ultrasound. Intravascular ultrasound imaging was performed in 25 lesions before and after Palmaz-Schatz stent implantation. In the 25 lesions with ultrasound images before and after stent deployment angiographic percent diameter stenosis decreased from 71% ± 11% to 6% ± 14%. By ultrasound there was a gain in luminal area from 2.0 mm² ± 1.5 mm² to 6.6 mm² ± 2.1 mm² owing to a gain in external elastic membrane area of 2.5 mm² ± 1.7 mm² and reduction of plaque area of 2.1 mm² ± 1.7 mm². Calcified lesions (n = 8) showed significantly less relative luminal gain (218% ± 128% vs. 421% ± 276%, P = .01), and stent expansion was significantly less symmetric (minimal/maximal stent diameter 0.8 ± 0.1 vs. 0.9 ± 0.1, P = .002) as compared to non-calcified lesions (n = 17). The difference in lumen area within the stent between the previously stenotic area and the ends of the stent was significantly larger in calcified lesions as compared to non-calcified lesions (29 ± 28% vs. 8 ± 23%, P = .03). Both vessel stretch and plaque reduction contribute to the luminal gain after coronary stenting. Calcified lesions interfere with optimal stent expansion. © 1996 Wiley-Liss, Inc.     

Inhibition of neo‐intimal hyperplasia in porcine coronary arteries utilizing a novel paclitaxel‐coated scoring balloon catheter

Objective: Scoring balloons are particularly useful in the acute treatment of fibro‐calcific, bifurcation and in‐stent restenosis lesions but have not been shown to affect the restenosis rate. Conventional balloons coated with paclitaxel have recently been shown to reduce restenosis rates in certain lesion subsets, but are associated with suboptimal acute results. A novel paclitaxel‐coated scoring balloon was developed to overcome these limitations. Design: AngioSculpt^® scoring balloons (SB) were coated with paclitaxel admixed with a specific excipient. Setting and Interventions: Four in vitro and in vivo studies were performed: (a) loss of the drug during passage to the lesion, (b) transfer of the drug to the vessel wall; (c) inhibition of neo‐intimal proliferation in porcine coronary arteries as compared to uncoated SB and the Paccocath?, and (d) evaluation of the dose‐response to 1.5–12 μg of paclitaxel/mm². Main outcome measures and Results: Drug loss during delivery to the lesion was 17% ± 8%, and transfer to the vessel wall was 9% ± 4% of dose on unused balloons. The paclitaxel‐coated SB resulted in a lower late lumen loss of 0.27 ± 0.24 mm compared to 1.4 ± 0.7 mm with the uncoated SB (P = 0.001). Histomorphometry revealed larger luminal areas of 6.8 ± 1.6 mm² (paclitaxel‐coated SB) and 5.8 ± 1.7 mm² (Paccocath) as compared to the uncoated SB (2.3 ± 1.5 mm²; P = 0.001). No coating related adverse effects were observed on follow‐up angiography or histologic examination at the treatment site or downstream myocardium. Conclusion: A novel paclitaxel‐coated SB leads to a significant inhibition of neointimal proliferation in the porcine coronary model. © 2013 Wiley Periodicals, Inc.     

Intravascular ultrasound assessment of distal left main bifurcation disease: The importance of the polygon of confluence of the left main,left anterior descending,and left circumflex arteries

Background : The polygon of confluence (POC) represents the zone of confluence of the distal left main (LM), ostial left anterior descending (LAD), and ostial left circumflex (LCX) arteries. Methods : We used intravascular ultrasound (IVUS) to assess the POC pre and post‐drug‐eluting stent implantation for unprotected distal LM disease. Four segments within 82 LM bifurcation lesions were defined by longitudinal IVUS reconstruction: (1) ostial LAD, (2) POC, and (3) distal LM (DLM)—from LAD‐pullback, and (4) ostial LCX from LCX‐pullback. Results : Preprocedural minimum lumen area (MLA) and poststenting minimum stent area (MSA) within the LM were mainly located within the POC (51 and 71%). On ROC analysis, a cut‐off of the MLA within the POC of 6.1 mm² predicted significant LCX carinal stenosis (85% sensitivity, 52% specificity, AUC = 0.7, 95% CI = 0.57–0.78, P < 0.01). Poststenting MSA within the distal LM proximal to the carina (to include DLM and POC) positively correlated with the preprocedural MLA within the POC (r = 0.283, P = 0.02); it was significantly smaller in 48 lesions with a pre‐PCI MLA within the POC < 6.1 mm² versus 25 lesions with a pre‐PCI MLA ≥6.1 mm² (7.5 ± 2.1 mm² vs. 8.6 ± 2.0 mm², P = 0.04). Independent predictors for poststenting LCX carinal MLA also included preprocedural MLA within the POC (β = 0.240, 95% CI = 0.004–0.353, P = 0.04). Conclusion : The MLA within the POC was a good surrogate reflecting the overall severity of LM bifurcation disease including ostial LCX stenosis pre‐PCI and the ability to expand a stent within the distal LM as well as final ostial LCX lumen area post‐PCI. © 2011 Wiley Periodicals, Inc.     

Bifurcation coronary lesions treated with the "crush" technique: an intravascular ultrasound analysis

OBJECTIVES: We report intravascular ultrasound (IVUS) findings after crush-stenting of bifurcation lesions. BACKGROUND: Preliminary results with the crush-stent technique are encouraging; however, isolated reports suggest that restenosis at the side branch (SB) ostium continues to be a problem. METHODS: Forty patients with bifurcation lesions underwent crush-stenting with the sirolimus-eluting stent. Postintervention IVUS was performed in both branches in 25 lesions and only the main vessel (MV) in 15 lesions; IVUS analysis included five distinct locations: MV proximal stent, crush area, distal stent, SB ostium, and SB distal stent. RESULTS: Overall, the MV minimum stent area was larger than the SB (6.7 +/- 1.7 mm2 vs. 4.4 +/- 1.4 mm2, p < 0.0001, respectively). When only the MV was considered, the minimum stent area was found in the crush area (rather than the proximal or MV distal stent) in 56%. When both the MV and the SB were considered, the minimum stent area was found at the SB ostium in 68%. The MV minimum stent area measured <4 mm2 in 8% of lesions and <5 mm2 in 20%. For the SB, a minimum stent area <4 mm2 was found in 44%, and a minimum stent area <5 mm2 in 76%, typically at the ostium. "Incomplete crushing"--incomplete apposition of SB or MV stent struts against the MV wall proximal to the carina--was seen in >60% of non-left main lesions. CONCLUSIONS: In the majority of bifurcation lesions treated with the crush technique, the smallest minimum stent area appeared at the SB ostium. This may contribute to a higher restenosis rate at this location.