Mean Lumen Area Research Articles

Measurements of Lumen Areas and Diameters of Proximal and Middle Coronary Artery Segments in Subjects Without Coronary Atherosclerosis

There are plenty of data on morphology and lumen dimensions of diseased coronary arteries. However, information on normal coronary vessel anatomy is scarce. We provided computed tomography angiography-derived reference values of lumen dimensions in proximal and middle coronary segments in a healthy population with respect to gender and vessel dominance. Consecutive 2,849 computed tomography angiography examinations were reviewed to identify 201 subjects (77 men, patient age 50 ± 13 years) whose coronary arteries were free from any sign of atherosclerosis (calcium score 0, no detectable plaque). For all proximal and middle coronary segments, lumen areas (LAs) and lumen diameters were measured. Coronary vessel segmentation and dominance pattern were defined using the Syntax Score. Normal values of LAs and lumen diameters were significantly smaller for women compared with men except for the proximal right coronary artery and the left main coronary artery (LMCA) (20.2 ± 6.6 mm2 vs 23.0 ± 6.1 mm2, p = 0.0003, and 5.0 ± 0.8 mm vs 5.4 ± 0.7 mm, p = 0.0001). The lower limit of normal for the LMCA (defined as mean LA - 2 standard deviations) equaled 7.0 and 10.8 mm2 for women and men, respectively. Subjects with left (vs right) coronary dominance had significantly larger areas and diameters of the LMCA (26.2 ± 9.2 mm2 vs 20.7 ± 6.0 mm2, p = 0.0017, and 5.7 ± 1.0 mm vs 5.1 ± 0.7 mm, p = 0.0017, respectively) and proximal left circumflex (13.8 ± 2.7 mm2 vs 10.4 ± 3.8 mm2, p = 0.0001, and 4.2 ± 0.4 mm vs 3.6 ± 0.7 mm, p = 0.0001, respectively) and smaller areas and diameters of the proximal right coronary artery (7.1 ± 2.0 mm2 vs 13.3 ± 3.6 mm2, p <0.0001, and 3.0 ± 0.4 mm vs 4.1 ± 0.6 mm, p <0.0001, respectively). In conclusion, gender and coronary artery dominance pattern significantly impact normal LAs and dimensions in subjects without coronary atherosclerosis.

Vascular response and healing profile of everolimus-eluting bioresorbable vascular scaffolds for percutaneous treatment of chronic total coronary occlusions: A one-year optical coherence tomography analysis from the GHOST-CTO registry

BackgroundBioresorbable vascular scaffolds (BVS) have been heralded with potential benefits that are especially desired in long lesions, including chronic total occlusions (CTOs). Procedural feasibility and mid-term outcomes of BVS in CTOs have been reported. However, there is still a paucity of data regarding the vascular and healing response to BVS in CTOs evaluated by optical coherence tomography (OCT). MethodsThis study included prospectively 21 patients who had a CTO lesion treated with a BVS. Angiography and OCT scan were recorded at either post-implantation and 1-year follow-up. Quantitative coronary angiography and OCT analyses were performed by an independent core laboratory. ResultsThe angiographic analysis showed a significant increase in the percentage of in-segment diameter stenosis at 1year (11.89±9.5% vs. 21.84±11.7%; p=0.002). The OCT analysis showed a trend (p=0.07) towards increased mean scaffold area and significant reductions in mean lumen diameter (3.1±0.36mm vs. 2.85±0.47mm; p=0.0046), mean lumen area (7.8±1.73mm2 vs. 6.76±2mm2; p=0.0082) and minimal lumen area (5.26±1.86mm2 vs. 3.56±1.52mm2; p<0.0001). Malapposition area and volume decreased from 0.26±0.17mm2 to 0.08±0.1mm2 (p=0.0003) and from 14.17±12.92mm3 to 3.99±4.46mm3 (p=0.0014), respectively. The rate of uncovered or malapposed struts, measured at the frame level, was 5.29±6.48% at 1year. ConclusionsIn a small series of CTO patients treated with BVS implantation, OCT outcomes at 1year displayed an overall favorable vascular response and healing profile.

Clinical study of optical coherence tomography in the diagnosis of peripheral pulmonary artery thrombus

BackgroundPeripheral pulmonary artery thrombus (PPT) is common in the clinic. However, due to the lack of an ideal diagnostic tool, PPT cannot be quickly diagnosed and effectively treated at present. Optical coherence tomography (OCT) is a new intravascular imaging technique that is characterized by high image resolution. This technique is suitable for small vessel imaging and has the ability to distinguish red and white thrombi. ObjectiveThis study aimed to evaluate the value of OCT in the diagnosis of PPT and in identifying the nature of thrombi by comparing the difference in sensitivity between OCT and selective pulmonary angiography (SPA). MethodsHighly suspected PPT patients were enrolled in this study. Pulmonary ventilation/perfusion (V/Q) mismatch pulmonary segments or peripheral pulmonary arteries were chosen. SPA was performed first, followed by OCT imaging. The diagnostic standard of thrombus with SPA was an intraluminal filling defect. The procedure and criteria for OCT diagnosis of thrombus were previously introduced in intracoronary OCT thrombus images. The diameter of the imaging vessels was measured, and they were grouped according to diameter. The diameter was <2mm in the distal segment group, 2–3mm in the middle segment group, and >3mm in the proximal segment group. The recognition abilities of intravascular thrombus with the different diameters of these two techniques were compared. Patients with obvious clinical symptoms and more red thromboses revealed by OCT were given standardized anticoagulant therapy for half a year. The clinical symptoms, 6-minute walking test and changes in the thrombus in the OCT images of these patients before and after treatment were observed. ResultsA total of 22 patients with highly suspected PPT were suggested to undergo V/Q inspection. Finally, 12 patients were eligible for the study. SPA and OCT were performed in 61 peripheral pulmonary arteries in all 12 patients. The ideal SPA and OCT images obtained from a total of 76 blood vessel segments were suitable for comparative analysis. A total of 62 thrombi were found by SPA. Among these, eight thrombi were in the distal segment, 29 thrombi were in the middle segment, and 25 thrombi were in the proximal segment. A total of 81 thrombi were found by OCT, among which 22 thrombi were in the distal segment, 31 were in the middle segment, and 28 were in the proximal segment. There was a significant difference between two groups in the distal segment group (P=0.013), while there was no significant difference between two groups in the middle segment group or the proximal segment group (P>0.05). In addition to all the thrombi found by SPA, OCT found other thrombi that were missed by SPA. According to previous OCT images for determining the nature of thrombi, OCT revealed 81 thrombi, of which 48 (59%) were red thrombi and 33 (41%) were white thrombi. Then, seven patients who had obvious clinical symptoms and more red thrombi in the peripheral pulmonary artery were given anticoagulant therapy for six months. After treatment, these symptoms were improved, oxygenation indexes increased, and the six-minute walking test was extended in all these patients. After anticoagulation therapy, five patients underwent OCT review. These OCT images were matched and compared before and after anticoagulation therapy. The results revealed that most of the thrombi had disappeared, and a small amount of red thrombi turned white as the volume reduced. The mean lumen area before and after treatment was 2.05±1.03mm2 and 2.86±1.24mm2, respectively, and the difference was statistically significant (P=0.035). ConclusionOCT can clearly show the structure of the lumen and the wall of the peripheral pulmonary artery tube. The sensitivity of the diagnosis of PPT with a diameter of <2mm was higher than that of SPA. Moreover, OCT has the ability to distinguish between red and white thrombi, which is of guiding significance in anticoagulant therapy.

Detection of early changes in the coronary artery microstructure after heart transplantation: A prospective optical coherence tomography study

Optical coherence tomography (OCT) enables in-vivo cardiac allograft vasculopathy (CAV) microstructure characterization. Early coronary artery microstructure changes after heart transplantation (HTx) may provide valuable mechanistic information regarding CAV development. Our in this study was to describe and characterize changes in the coronary artery microstructure during the first year after HTx using serial OCT scans. Twenty-six patients were enrolled at routine baseline coronary angiography 3 months after HTx. Coronary OCT scans were performed on all 3 major vessels at baseline and were repeated 12 months after HTx. We contoured the vessel layers for absolute and relative measurements. Lipid plaques, calcified plaques, layered fibrotic plaques (LFPs) and bright spots were analyzed by delineating circumferential borders and measuring angulation of total circumference. A total of 8,789 frames from 71 vessels were analyzed after 3 and 12 months (vessel length 79 ± 24 mm vs 82 ± 23 mm, respectively, p = 0.39). Mean intima area increased by 20% from 3 months to 12 months (1.6 [1.2 to 2.7] mm2 vs 1.9 [1.3 to 3.2] mm2, p < 0.0001). Mean lumen area decreased by 2% (9.1 [7.5 to 11.6] mm2 vs 8.9 [6.9 to 10.9] mm2, p < 0.01). LFPs showed an almost 5-fold increase at follow-up (1.0% [0% to 6.5%] vs 4.8% [0% to 24.5%], p < 0.0001). Bright spots were also detected more frequently at 12 months (0% [0% to 2.8%] vs 0.8% [0% to 6.8%], p < 0.001). We found no significant difference in extent of lipid plaque (p = 0.78) or calcified plaque (p = 0.37) during follow-up. The intima area change and LFP progression during follow-up correlated strongly (r2 = 0.51, p < 0.0001). Early CAV formation during the first year after HTx is characterized by a pronounced intima layer thickening strongly associated with LFP progression. In contrast, the extent of lipid plaque and calcifications remained stable. LFP formation may be a key mechanism in CAV.

Femoral artery plaque characteristics, lower extremity collaterals, and mobility loss in peripheral artery disease.

Little is known about the prognostic significance of specific characteristics of magnetic resonance imaging (MRI) measured plaque in the superficial femoral artery (SFA). Associations of MRI-measured plaque quantity, lumen area, and plaque composition in the SFA with subsequent mobility loss were studied in people with lower extremity peripheral artery disease (PAD). Participants with an ankle-brachial index (ABI) < 1.00 were identified from Chicago medical centers and underwent direct visualization of atherosclerotic plaque in the SFA using MRI. Participants were followed annually for up to 4 years. Mobility loss was defined as becoming unable to walk up and down a flight of stairs or walk one-quarter of a mile without assistance among participants without mobility impairment at baseline. Analyses adjusted for age, sex, race, comorbidities, ABI, physical activity, and other confounders. Of 308 PAD participants without baseline mobility impairment, 100 (32.5%) developed mobility loss during follow-up. Compared to the lowest mean plaque area tertile at baseline, participants in the highest (worst) plaque area tertile had a higher rate of mobility loss (hazard ratio (HR) = 2.08, 95% confidence interval (CI) = 1.14-3.79, p = 0.018). Compared to the highest mean lumen area tertile, the smallest (worst) mean lumen area tertile was associated with greater mobility loss (HR = 2.18, 95% CI = 1.20-3.96, p = 0.011). Neither lipid rich necrotic core nor calcium in the SFA were associated with mobility loss. In conclusion, greater plaque quantity and smaller lumen area in the proximal SFA, but not lipid rich necrotic core or calcium, were associated with higher mobility loss in people with PAD.

Long-term invasive follow-up of bioresorbable vascular scaffold: Optical Coherence Tomography assessment of jailed side branches.

Little is known about the long term development of the tissue bridges covering the struts of bioresorbable vascular scaffold (BVS) at the side branches (SB) ostium. This study aims at assessing the resorption process of jailed SB after BVS implantation. We performed both Optical Coherence Tomography (OCT) and Intravascular Ultrasound (IVUS) analysis of 7 patients enrolled in the ABSORB Cohort B trial at our center. Orifice SB area and mean thickness of tissue bridge covering SB were calculated from 2D assessment. The number of SB orifice compartments separated by BRS struts was analysed by using 3D OCT reconstruction. At 5years follow-up, no struts could be identified. Between 3 and 5years, both lesion-level and cross section-level OCT findings showed a significant increase in Mean lumen area (MLA) (4.67±1.66mm2 vs. 5.57±1.57mm2; p=0.04) as well as Minimum Lumen Area (MinLA) (5.98±1.98mm2 vs. 6.73±1.87mm2; p=0.04). Moreover, eccentricity index showed a significant reduction between 3 and 5years (0.28±0.35mm2 vs. 0.16±0.06mm2; p=0.04). We identified a total of 3 SBs ostia in the segments treated with BVS. Between 3 and 5years follow-up in all SB analysed, we detected a decrease of mean tissue bridge thickness and an increase of calculated SBs area. In our serial OCT, a significant decrease of tissue bridge formation together with SB orifice area enlargement from 3 to 5year follow-up has been proved.

Arterial Remodeling After Bioresorbable Scaffolds and Metallic Stents

BackgroundAlthough previous observational studies have documented late luminal enlargement and expansive remodeling following implantation of a bioresorbable vascular scaffold (BVS), no comparison with metallic stents has been conducted in a randomized fashion. ObjectivesThis study sought to compare vessel remodeling patterns after either Absorb BVS or Xience metallic drug-eluting stent (DES) implantation (Abbott Vascular, Santa Clara, California) and determine the independent predictors of remodeling. MethodsIn the ABSORB II randomized trial, 383 lesions (n = 359) were investigated by intravenous ultrasound both post-procedure and at 3-year follow-up. According to vessel and lumen area changes over 3 years, we categorized 9 patterns of vessel remodeling that were beyond the reproducibility of lumen and vessel area measurements. ResultsThe relative change in mean vessel area was significantly greater with the BVS compared to the DES (6.7 ± 12.6% vs. 2.9 ± 11.5%; p = 0.003); the relative change in mean lumen area was significantly different between the 2 arms (1.4 ± 19.1% vs. −1.9 ± 10.5%, respectively; p = 0.031). Multivariate analysis indicated that use of the BVS, female sex, balloon-artery ratio >1.25, expansion index ≥0.8, previous percutaneous coronary intervention, and higher level of low-density lipoprotein cholesterol were independent predictors of expansive remodeling. Furthermore, in the BVS arm, necrotic core pre-procedure was an independent determinant of expansive remodeling. ConclusionsExpansive vessel wall remodeling was more frequent and intense with the BVS than the metallic DES and could be determined by patient baseline characteristics and periprocedural factors. The clinical effect of the observed lumen and vessel remodeling must be investigated in further large clinical studies to optimize the clinical outcome of patients and lesions treated by bioresorbable scaffolds. (ABSORB II Randomized Controlled Trial; NCT01425281)

Analysis of optical coherence tomography of early and very late stent restenosis after drug-eluting stent implantation

Objective: Using optical coherence tomography (OCT) to analyze the morphological characteristics of lesions between early in-stent restenosis (E-ISR) and very late in-stent restenosis (VL-ISR) after drug-eluting stents (DES) implantation. Methods: In 25 patients (DES) with ISR, OCT images were acquired before percutaneous coronary intervention (PCI), the morphological characteristics of E-ISR (<1 years, n=14) and VL-ISR (>3 years, n=11) were compared.The quantitative and qualitative analysis of the entire stent and the minimum lumen area (MLA) site were carried out respectively. OCT quantitative restenotic tissue analysis included the assessment of mean lumen area, mean stent area, mean neointimal area and mean neointimal burden.OCT qualitative restenotic tissue analysis included the assessment of tissue structure [homogeneous or heterogeneous intima (lipid-rich neoitima, thin-cap fibroatheroma (TCFA)-like intima)], presence of microvessels, intraluminal material (red thrombus, pale thrombus), disrupted intima with cavity and tissue prolapse and was performed at every 1-mm slice of the entire stent. Results: Compared with the E-ISR group, the proportion of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group (60.57% vs 32.93%, P=0.005), and both peristent and intraintimal microvessels were more frequently observed in the VL-ISR group (P<0.05). In addition, lipid-rich neointima (72.7% vs 21.4%, P=0.017), TCFA-like intima (54.5% vs 7.1%, P=0.021), disrupted intima with visible cavity (63.6% vs 7.1%, P=0.007) and red thrombus (63.6% vs 7.1%, P=0.007) were observed more frequently in the VL-ISR group compared with E-ISR group for the entire stent.The heterogeneous intima was observed more frequently in the VL-ISR group (90.9% vs 35.7%, P=0.012) at the MLA sites.Intraintimal microvessels and disrupted intima with visible cavity were observed only in the VL-ISR group. Conclusions: OCT imaging indicates that the morphological characteristics of restenosis lesions in VL-ISR are different from those in E-ISR.The atherosclerotic changes of neointima, such as lipid-rich neointima, disrupted intima with cavity and microvessels are more often observed in VL-ISR lesions after DES implantation compared with E-ISR.Progression of the atherosclerosis within neointima after DES implantation may be associated with VL-ISR.

A three-dimensional approach foridentifying small pulmonary vesselsinsmokers.

This study aims to develop a computerized scheme that utilizes a differential geometric approach to identify pulmonary vessels and then evaluate the performance of the scheme on the CT images of heavy smokers. The scheme consists of two primary steps to segment entire lung vascular tree and identify the number of pulmonary vessels in a cross section. The scheme performance including accuracy, consistency, and efficiency was assessed using 102 chest CT scans. Further assessment was performed on the relationship between pulmonary vessels and the extent of emphysema as well as pulmonary artery alteration. The mean number of vessels in the cross section at the 5th generation was 17.84±4.74 and 17.23±4.85 assessed by computerized scheme and radiologists, respectively, which are significantly different (t = 2.12, p = 0.055). The results were consistent with those obtained by using a semi-automatic tool (r = 0.75, p = 0.01). In addition, in the 5th generation, the mean number of vessels was inversely related to the percentage of the low attenuation area (r = -0.704, p = 0.000), the mean lumen area of pulmonary vessel was inversely related to the mean value of main pulmonary artery diameter (r = -0.617, p = 0.000). The computational time of segmenting vessels was 6.50±0.02 seconds, which is much less than the average 8 minutes of the time spent by radiologists using the semi-automatic tool. Applying the computerized scheme yields reasonable performance on the segmentation of pulmonary vessels. The alteration of pulmonary vessels may reflect the presence of pulmonary hypertension, as well as the extent of emphysema.

Serial quantitative magnetic resonance angiography follow-up of renal artery dimensions following treatment by four different renal denervation systems.

Renal sympathetic denervation (RDN) is being studied as a therapeutic option for patients with therapy-resistant hypertension. It remains unclear if the procedure affects the renal arteries in such a way that luminal narrowing might occur at the mid to longer term. The aim of the present study was to assess renal artery integrity accurately at the medium to long term using recently validated quantitative magnetic resonance angiography software in patients treated with four different RDN devices. In a prospective cohort of 27 patients referred for RDN, quantitative magnetic resonance angiography (MRA) was used to assess 52 vessels at baseline, six, and 12 months post treatment with one of four different devices. No renal artery stenosis was seen at six or 12 months. The average mean lumen area was 26.6±7.3 mm2 at baseline versus 25.0±7.1 mm² and 25.0±6.1 mm² at six and 12 months, respectively, resulting in a late loss of 1.6 mm2 at six months and 1.9 mm2 at 12 months. No differences were observed in the arterial response to RDN with the four different systems used. There was no correlation between post-procedural dissections, oedema or thrombi as detected with invasive imaging, and luminal narrowing at follow-up. Quantitative MRA of patients treated with RDN revealed no significant change in renal artery dimensions up to 12-month follow-up. The lack of a change in renal artery luminal dimensions was irrespective of the arterial response to the individual devices used.

Intermediate analysis of magnesium alloy covered stent for a lateral aneurysm model in the rabbit common carotid artery.

To analyze the outcomes of a magnesium alloy covered stent (MACS) for a lateral aneurysm model in common carotid artery (CCA). In 32 rabbits, a MACS (group A, n = 17) or a Willis covered stent (WCS; group B, n = 15) was inserted and the rabbits were sacrificed 1, 3, 6, or 12 months after stenting. Angiography and intravascular ultrasound (IVUS) were performed at 3, 6, and 12 months. Scanning electron microscopy was performed for six stents in each group at 1, 3, and 6 months, and histopathology and histomorphology were conducted at 3 (n = 4), 6 (n = 4), and 12 (n = 12) months. Final angiography showed complete occlusion of the aneurysms in 12 cases. IVUS at 6 and 12 months revealed a significant increase in mean lumen area of the stented CCA in group A and also showed greater mean lumen area in group A than in group B. The endothelialization process was quicker in group A than in group B. MACS is effective for occlusion of lateral aneurysms and is superior to WCS in growth of the stented CCA and endothelialization. Further work is needed to make this device available for human use. • The MACS is an effective approach for occlusion of a lateral aneurysm. • IVUS showed that the CCA could grow following degradation of the MACS. • The lumen area of the stented CCA was excellent in MACS. • HE staining displayed the degradation of the magnesium alloy stent. • Combination of IVUS and DSA were applied in this study.

Overlapping implantation of bioresorbable novolimus-eluting scaffolds: an observational optical coherence tomography study.

Overlapping implantation of bioresorbable vascular scaffolds is frequently necessary, but its influence on vessel and scaffold structure has not been thoroughly analyzed previously. The aim of this study was to analyze the acute effects of overlapping implantation on BRS as determined by optical coherence tomography (OCT). A total of 38 patients with de novo coronary artery stenoses who underwent OCT in the context of implantation of novolimus-eluting BRS (DESolve, Elixir Medical Corporation, Sunnyvale, California, USA) were investigated. In 15 patients, overlapping implantation of two BRS was performed, while 23 patients with implantation of one single BRS served as the control group. OCT data were retrospectively analyzed regarding acute scaffold implantation results. There were no significant differences between the overlap and control group in terms of residual in-scaffold area stenosis, scaffold area, mean or minimal lumen area, eccentricity index, incomplete scaffold apposition area or malapposition. While strut fracture was slightly more frequent in BRS with overlap its incidence was low overall. In patients with overlapping BRS, overlap segments did not display smaller lumen areas than segments without overlap (mean lumen area overlap: 8.16±2.97mm2 vs. no overlap: 7.70±2.55mm2; p=0.71; minimal lumen area overlap: 6.83±2.71mm2 vs. no overlap: 6.17±2.58mm2; p=0.37). Acute mechanical performance of novolimus-eluting BRS is not impaired by overlapping implantation. It can be assumed that vessel expansion compensates for the double scaffold layer in the overlap area resulting in a similar lumen area in overlap areas and in those with a single strut layer.

LINKING LUNG AIRWAY STRUCTURE TO PULMONARY FUNCTION VIA COMPOSITE BRIDGE REGRESSION.

The human lung airway is a complex inverted tree-like structure. Detailed airway measurements can be extracted from MDCT-scanned lung images, such as segmental wall thickness, airway diameter, parent-child branch angles, etc. The wealth of lung airway data provides a unique opportunity for advancing our understanding of the fundamental structure-function relationships within the lung. An important problem is to construct and identify important lung airway features in normal subjects and connect these to standardized pulmonary function test results such as FEV1%. Among other things, the problem is complicated by the fact that a particular airway feature may be an important (relevant) predictor only when it pertains to segments of certain generations. Thus, the key is an efficient, consistent method for simultaneously conducting group selection (lung airway feature types) and within-group variable selection (airway generations), i.e., bi-level selection. Here we streamline a comprehensive procedure to process the lung airway data via imputation, normalization, transformation and groupwise principal component analysis, and then adopt a new composite penalized regression approach for conducting bi-level feature selection. As a prototype of composite penalization, the proposed composite bridge regression method is shown to admit an efficient algorithm, enjoy bi-level oracle properties, and outperform several existing methods. We analyze the MDCT lung image data from a cohort of 132 subjects with normal lung function. Our results show that, lung function in terms of FEV1% is promoted by having a less dense and more homogeneous lung comprising an airway whose segments enjoy more heterogeneity in wall thicknesses, larger mean diameters, lumen areas and branch angles. These data hold the potential of defining more accurately the "normal" subject population with borderline atypical lung functions that are clearly influenced by many genetic and environmental factors.

Magnesium alloy covered stent for treatment of a lateral aneurysm model in rabbit common carotid artery: An in vivo study.

Magnesium alloy covered stents have rarely been used in the common carotid artery (CCA). We evaluated the long-term efficacy of magnesium alloy covered stents in a lateral aneurysm model in rabbit CCA. Magnesium alloy covered stents (group A, n = 7) or Willis covered stents (group B, n = 5) were inserted in 12 New Zealand White rabbits and they were followed up for 12 months. The long-term feasibility for aneurysm occlusion was studied through angiograms; the changes in vessel area and lumen area were assessed with IVUS. Complete aneurysmal occlusion was achieved in all aneurysms. Angiography showed that the diameter of the stented CCA in group A at 6 and 12 months was significantly greater than the diameter immediately after stent placement. On intravascular ultrasound (IVUS) examination, the mean lumen area of the stented CCA in group A was significantly greater at 6 and 12 months than that immediately after stent placement; the mean lumen area was also significantly greater in group A than in group B at the same time points. The magnesium alloy covered stents proved to be an effective approach for occlusion of lateral aneurysm in the rabbit CCA; it provides distinct advantages that are comparable to that obtained with the Willis covered stent.

Bioresorbable vascular scaffold (BVS) for the treatment of native coronary artery stenosis: one year outcome

Abstract Background The newer generation of Bioresorbable Vascular Scaffold ABSORB (BVS 1.1) showed better outcome in regard to scaffold area reduction as a result of improved scaffold design and enhanced polymer processing. Objective To assess the safety and efficacy of treating significant native coronary artery stenosis using ABSORB BVS. Methods Ninety-nine patients with de novo native significant coronary artery stenosis were selected between September 2012 and September 2014 and were treated using ABSORB BVS. For each patient, the target and the peri-scaffold segments (5 mm proximal and distal to the scaffold edge) were analyzed by Quantitative Coronary Angiography (QCA) and Intravascular Ultrasound (IVUS) immediately after the procedure and at one year of follow-up. The major clinical endpoint was ischemia-driven major adverse cardiac events (ID-MACE) defined as a composite of cardiac death, myocardial infarction or ischemia-driven target lesion revascularization (ID-TLR). Results At one year, the overall scaffold area did not demonstrate any significant change. The angiographic insegment late lumen loss was estimated to be 0.11 ± 0.19 mm, while the IVUS assessment revealed a non-significant decrease in the minimal lumen area by 0.5% (p = 0.79), without significant change in the mean lumen area. There were no reported cardiac deaths. However, two cases of ID-TLR were recorded, one case with STEMI after two weeks due to thrombosis at the distal edge of the BVS and another case with restenosis after one year. Both were treated with metallic drug-eluting stents (Xience V). At one year the overall ID-MACE was found to be 2%. Conclusion The performance of ABSORB BVS in the treatment of significant de novo native coronary artery stenosis makes it an attractive option with favorable early and late outcome.

Long-term invasive follow-up of the everolimus-eluting bioresorbable vascular scaffold: five-year results of multiple invasive imaging modalities.

Invasive imaging modalities have shown restoration of vasomotion, prevention of restenosis and, most importantly, increase in lumen area between six months and two years after first-generation everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) implantation. Our aim was to assess whether these positive findings were sustained in the long term. Patients included in the ABSORB cohort A from the Thoraxcenter Rotterdam cohort underwent coronary catheterisation including angiography, intravascular ultrasound (IVUS), virtual histology, optical coherence tomography (OCT) and vasomotion testing at five years. Eight out of 16 patients underwent catheterisation and scaffold assessment with multiple imaging modalities. A trend towards an increase in minimum luminal diameter was observed between two and five years by angiography (1.95±0.37 mm vs. 2.14±0.38 mm; p=0.09). IVUS data showed an increase in mean lumen area at five years (6.96±1.13 mm2) compared to six months (6.17±0.74 mm2; p=0.06) and two years (6.56±1.16 mm2; p=0.12), primarily due to a persistent reduction in plaque area size between six months and five years (9.17±1.86 mm2 vs. 7.57±1.63 mm2; p=0.03). The necrotic core area was reduced at five years compared to post-procedural results. In OCT, an increase in mean and minimal luminal area was observed. Moreover, no scaffold struts could be identified and a smooth endoluminal lining was observed. The scaffolded coronary segment did not show signs of endothelial dysfunction with acetylcholine testing. At five years, the Absorb BVS is no longer discernible by any invasive imaging method and endothelial function is restored. Late luminal enlargement persists up to five years of follow-up without adaptive vessel remodelling.

Anatomical and Physiological Changes after Paclitaxel-Coated Balloon for Atherosclerotic De Novo Coronary Lesions: Serial IVUS-VH and FFR Study.

AimsTo assess the serial changes of de novo coronary lesions treated with paclitaxel-coated balloon (PCB) using intravascular ultrasound virtual histology (IVUS-VH) and fractional flow reserve (FFR).Method and ResultsThis prospective observational study enrolled 27 patients with coronary artery disease treated with PCB who underwent coronary angiography, IVUS-VH and FFR before, immediately after intervention and at 9 months. 28 de novo lesions were successfully treated with PCB. Angiographic late luminal loss was 0.02 ± 0.27mm. Mean vessel and lumen areas showed increase at 9 months (12.0 ± 3.5mm2 to 13.2 ± 3.9mm2, p <0.001; and 5.4 ± 1.2mm2 to 6.5 ± 1.8mm2, p <0.001, respectively). Although mean plaque area was unchanged (6.6 ± 2.6mm2 to 6.6 ± 2.4mm2, p = 0.269), percent atheroma volume decreased significantly (53.4 ± 7.9% to 49.5 ± 6.4%, p = 0.002). The proportion of plaque compositions including fibrous, fibrofatty, dense calcium and necrotic core by IVUS-VH was unchanged at 9 months. The FFR of the treated lesion was 0.71 ± 0.13 pre-procedure, 0.87 ± 0.06 post-procedure and 0.84 ± 0.06 at follow-up.ConclusionsDe novo coronary lesions treated with PCB showed persistent anatomical and physiological patency with plaque redistribution and vessel remodeling without chronic elastic recoil or plaque compositional change during follow-up.

Effects of repeated gas sterilization on closure rates of ameroid ring constrictors in vitro.

To determine the effect of repeated gas sterilization on rate of closure of ameroid ring constrictors in vitro. Twenty-four 3.5-mm ameroid ring constrictors. Ameroid ring constrictors were allocated to 1 of 4 treatment groups (6/group) to undergo gas sterilization 0, 1, 5, or 10 times. After sterilization, constrictors were incubated in canine plasma at a protein concentration of 3 g/dL for 27 days. A digital camera was used to obtain images of the constrictors prior to and at various points during incubation, and lumen diameter was measured. Mean ± SD percentage of lumen closure for all groups of ameroid ring constrictors combined was 85.2 ± 1.6% at day 0 (prior to plasma incubation) and 95.4 ± 0.8% at day 27. Mean lumen area was 3.64 ± 0.43 mm(2) (95% confidence interval, 2.67 to 4.77 mm(2)) at day 0 and 1.32 ± 0.25 mm(2) (95% confidence interval, 0.76 to 2.04 mm(2)) at day 27. None of the ameroid ring constrictors had closed completely by day 27. Overall closure rates for ameroid ring constrictors appeared to be unaffected by repeated gas sterilization up to 10 times. Findings suggested that veterinary surgeons can resterilize ameroid ring constrictors up to 10 times with confidence that ring properties would remain suitable for clinical use.

Linking wood anatomy and xylogenesis allows pinpointing of climate and drought influences on growth of coexisting conifers in continental Mediterranean climate.

Forecasted warmer and drier conditions will probably lead to reduced growth rates and decreased carbon fixation in long-term woody pools in drought-prone areas. We therefore need a better understanding of how climate stressors such as drought constrain wood formation and drive changes in wood anatomy. Drying trends could lead to reduced growth if they are more intense in spring, when radial growth rates of conifers in continental Mediterranean climates peak. Since tree species from the aforementioned areas have to endure dry summers and also cold winters, we chose two coexisting species: Aleppo pine (Pinus halepensisMill., Pinaceae) and Spanish juniper (Juniperus thuriferaL., Cupressaceae) (10 randomly selected trees per species), to analyze how growth (tree-ring width) and wood-anatomical traits (lumen transversal area, cell-wall thickness, presence of intra-annual density fluctuations-IADFs-in the latewood) responded to climatic variables (minimum and maximum temperatures, precipitation, soil moisture deficit) calculated for different time intervals. Tree-ring width and mean lumen area showed similar year-to-year variability, which indicates that they encoded similar climatic signals. Wet and cool late-winter to early-spring conditions increased lumen area expansion, particularly in pine. In juniper, cell-wall thickness increased when early summer conditions became drier and the frequency of latewood IADFs increased in parallel with late-summer to early-autumn wet conditions. Thus, latewood IADFs of the juniper capture increased water availability during the late growing season, which is reflected in larger tracheid lumens. Soil water availability was one of the main drivers of wood formation and radial growth for the two species. These analyses allow long-term (several decades) growth and wood-anatomical responses to climate to be inferred at intra-annual scales, which agree with the growing patterns already described by xylogenesis approaches for the same species. A plastic bimodal growth behavior, driven by dry summer conditions, is coherent with the presented wood-anatomical data. The different wood-anatomical responses to drought stress are observed as IADFs with contrasting characteristics and responses to climate. These different responses suggest distinct capacities to access soil water between the two conifer species.

Chronic vascular response after self-expanding nitinol stent implantation in superficial femoral arteries: a serial intravascular ultrasound analysis

The mechanical properties of the self-expanding nitinol stents (SENS) and chronic biological stimulation on the wall from the SENS have not been fully investigated. This study evaluated the mechanical vascular response to SENS implantation in superficial femoral artery (SFA) lesions using serial volumetric intravascular ultrasound (IVUS). Twenty-five symptomatic patients due to de novo SFA lesions scheduled for SENS placement were prospectively enrolled. Serial IVUS studies were performed immediately after crossing with a guidewire, immediately after the procedure, and at a 8-month follow-up. Serial IVUS volumetric analysis was conducted after stent deployment and at follow-up. Mean stent, lumen and neointimal areas were calculated as the volume divided by the stent length, and the calcium arc was measured. At follow-up, SENS had increased 40.6% in overall volume. The chronic stent expansion tended to be larger, and the mean neointimal area at the 8-month follow-up was significantly larger in less calcified lesions compared to heavily calcified lesions. As a result, the mean late lumen area loss was significantly larger in lesions with calcium arcs of 0° and in the first and second quadrants than in those with calcium arcs in the third and fourth quadrants (2.8±7.2, 1.3±5.6, 0.6±5.9, 1.2±5.4, -0.8±5.2 mm(2), respectively; p<0.001). SENSs continued to enlarge with intimal proliferation over 8months in all lesions. Although arterial calcium affected the degree of chronic stent expansion during the follow-up period, neointimal proliferation was smaller in heavily calcified lesion compared to less calcified lesion following SENS implantation.