Lumen Reduction Research Articles

The effect of coronary calcification on diagnostic performance of machine learning-based CT-FFR: a Chinese multicenter study.

To investigate the effect of coronary calcification morphology and severity on the diagnostic performance of machine learning (ML)-based coronary CT angiography (CCTA)-derived fractional flow reserve (CT-FFR) with FFR as a reference standard. A total of 442 patients (61.2 ± 9.1 years, 70% men) with 544 vessels who underwent CCTA, ML-based CT-FFR, and invasive FFR from China multicenter CT-FFR study were enrolled. The effect of calcification arc, calcification remodeling index (CRI), and Agatston score (AS) on the diagnostic performance of CT-FFR was investigated. CT-FFR ≤ 0.80 and lumen reduction ≥ 50% determined by CCTA were identified as vessel-specific ischemia with invasive FFR as a reference standard. Compared with invasive FFR, ML-based CT-FFR yielded an overall sensitivity of 0.84, specificity of 0.94, and accuracy of 0.90 in a total of 344 calcification lesions. There was no statistical difference in diagnostic accuracy, sensitivity, or specificity of CT-FFR across different calcification arc, CRI, or AS levels. CT-FFR exhibited improved discrimination of ischemia compared with CCTA alone in lesions with mild-to-moderate calcification (AUC, 0.89 vs. 0.69, p < 0.001) and lesions with CRI ≥ 1 (AUC, 0.89 vs. 0.71, p < 0.001). The diagnostic accuracy and specificity of CT-FFR were higher than CCTA alone in patients and vessels with mid (100 to 299) or high (≥ 300) AS. Coronary calcification morphology and severity did not influence diagnostic performance of CT-FFR in ischemia detection, and CT-FFR showed marked improved discrimination of ischemia compared with CCTA alone in the setting of calcification. • CT-FFR provides superior diagnostic performance than CCTA alone regardless of coronary calcification. • No significant differences in the diagnostic performance of CT-FFR were observed in coronary arteries with different coronary calcification arcs and calcified remodeling indexes. • No significant differences in the diagnostic accuracy of CT-FFR were observed in coronary arteries with different coronary calcification score levels.

Mid-Term Clinical and Morphological Outcomes After Thoracic Endovascular Aortic Repair for Complicated Type B Aortic Dissection

Background: Complicated type B aortic dissections require surgery or thoracic endovascular aortic repair (TEVAR). In this study, we sought to explore the early and mid-term clinical efficacy of TEVAR treatment for Stanford complicated type B aortic dissection. Methods: From January 2012 to October 2017, the medical records and the aortic imaging data of 172 consecutive patients treated by TEVAR were retrospectively reviewed for statistical analysis. Aortic remodeling was evaluated based on the preoperative and one-year postoperative followed-up aortic CTA scan results. We analysed the diameters of the total aortic lumens, True and False lumens diameter and the thrombosis status at different five levels along the descending aorta. Results: The primary technical success rate was 97%, and the clinical success rate was 94.8%. At 1-year of aortic CTA follow-up after TEVAR, the true lumen diameter at the stented descending thoracic aorta increased significantly, the false lumen diameter significantly reduced. The remodeling process was stable with mild changes of true lumen increase and false lumen reduction at the unstented distal part of the descending thoracic and the abdominal aorta. Conclusion: This study confirmed that TEVAR treatment for complicated type B aortic dissection has a low mortality rate of mid-term follow-up outcomes. TEVAR stabilizes the size of the aorta and precipitates in FL thrombosis. However, FL in the abdominal aorta still patented and must be carefully observed for further long-term events.

Effects of PETTICOAT Technique in Acute and Chronic DeBakey Type III Aortic Dissection

Our objective was to examine the role of the provisional extension to induce complete attachment (PETTICOAT) technique in aortic remodeling of acute and chronic DeBakey type III aortic dissection. We also seek the proper timing of this technique to promote false lumen reduction.

Validation of A 3D Bioprinted Model of Airway Smooth Muscle – A Novel Tool to Study the Effects of Airway Stiffening in Asthma

BackgroundAsthma is a chronic obstructive airway disease characterized by airway wall remodeling and aberrant contraction of airway smooth muscle (ASM), which each contribute to clinical symptoms by restricting airflow. However, the precise link between airway mechanics and ASM contractility remains elusive, because ASM cell biology is routinely studied in 2D models that inadequately replicate the complex in‐vivo 3D microenvironment of healthy or diseased airways. We used a technique called 3D bioprinting to develop an experimental model of ASM in which we could characterize the response of ASM to altered mechanical loads in a realistic 3D structure.MethodsHuman ASM were resuspended at 2.5×107 cells/mL in a bio‐ink consisting of RGD‐coupled‐alginate (0.375% w/v), fibrinogen (5 mg/mL) and collagen‐I (1 mg/mL). Cells were then bioprinted using an Aspect Biosystems RX‐1 Bioprinter, as a ring‐shaped bundle of muscle constrained within a stiffness‐modifiable acellular alginate support (0.75–1.25% w/v). After bioprinting, constructs were thrombin treated (1.25 U/mL, 30 min) to initiate fibrin polymerization and maintained in standard ASM culture conditions. Cell health, viability and morphology were assessed with LDH assays, Hoechst/propidium‐iodide and filamentous‐actin staining respectively. Expression of ASM relevant genes was measured by qPCR. Reduction in lumen area representing contractile tone was tracked by live cell microscopy.ResultsASM bioprinted without acellular supports shortened excessively and rapidly lost structural integrity. Comparatively, including supports provided a mechanical load that controlled baseline shortening; cells supported by 0.75%, 1% and 1.25% alginate exhibited &gt;45%, &gt;25% and &lt;15% lumen reduction respectively. Constructs bioprinted in 1% supports exhibited high cell viability (&gt;80%) for up to 14 days in culture. Histology 4 days after printing revealed development of a highly organized tissue with evidence of cell‐cell contacts and alignment of actin fibres. Nuclei were evenly distributed in all axes indicating formation of a true 3D structure. Compared with 2D, cells in 3D had a higher mRNA abundance of myosin heavy chain, but vimentin and matrix metalloproteinase‐3 were lower (all p&lt;0.05). Importantly, administration of acetylcholine resulted in muscle contraction, while cytochalasin D caused a dramatic decrease in tone for all tissues with structural supports.ConclusionWe have validated a novel tool for studying ASM biomechanics. ASM displayed varying levels of baseline shortening to different mechanical loads, supporting that mechanical cues may have profound effects on cellular function. Further, higher abundance of contractile genes in 3D demonstrates adoption of a physiologically relevant phenotype. Moving forward, contraction, relaxation and calcium dynamics will be quantified across a range of stiffnesses. These data will help unmask mechanisms by which airway mechanics regulate ASM contractility, with important clinical relevance to asthma.Support or Funding InformationFunding: NSERC Discovery Grant (ARW), Research Manitoba Studentship (JO, SS)

Tau Protein in Human Brain Vascular Smooth Muscle

BackgroundIschemic stroke is a leading cause of long‐term disability and death worldwide. Thickening of the vascular wall and the reduction of lumen increase the incidence of ischemic stroke. Thus, therapeutic strategies targeting brain vascular narrowing should reduce the mortality and morbidity associated with ischemic stroke. Vascular smooth muscle cell (SMC) proliferation contributes to the development of vascular narrowing, however, cell signaling mechanisms of brain vascular SMC proliferation has not been defined. Tau is a microtubule‐associated protein indicated in various neurological pathologies, including Alzheimer’s disease. Although Tau protein is known to be expressed in neuronal cells, the role of Tau in brain vasculature is unknown. The present study tested the hypothesis that Tau is expressed in brain vascular SMCs.Methods &amp; ResultsImmunohistochemistry of postmortem brain tissues from human patients died of ischemic stroke demonstrated the expression of Tau protein in the vascular smooth muscle media layer. Western blotting of cell lysates from cultured human brain vascular SMCs revealed the occurrence of a Tau isoform with a molecular weight of ~45 kD that was knocked down by Tau siRNA. Treatment of cells with a potent mitogen of SMCs, platelet‐derived growth factor (PDGF), promoted the phosphorylation of Tau at Thr181, but not, Ser198, Ser199, Ser202, Thr205, Thr212, Ser214, Ser356, Ser404, or Ser422. A Tau protein aggregation inhibitor, methylene blue, inhibited human brain vascular SMC growth.ConclusionsThis is the first demonstration that Tau protein is expressed in any kind of vascular SMCs. Moreover, results showing that PDGF causes the phosphorylation of Tau at a specific amino acid and a Tau aggregation inhibitor suppresses cell growth suggest that Tau may play a role in cell growth signaling in brain vascular SMCs.Support or Funding InformationSupported by NIH

Ca2+ mobilization-dependent reduction of the endoplasmic reticulum lumen is due to influx of cytosolic glutathione

BackgroundThe lumen of the endoplasmic reticulum (ER) acts as a cellular Ca2+ store and a site for oxidative protein folding, which is controlled by the reduced glutathione (GSH) and glutathione-disulfide (GSSG) redox pair. Although depletion of luminal Ca2+ from the ER provokes a rapid and reversible shift towards a more reducing poise in the ER, the underlying molecular basis remains unclear.ResultsWe found that Ca2+ mobilization-dependent ER luminal reduction was sensitive to inhibition of GSH synthesis or dilution of cytosolic GSH by selective permeabilization of the plasma membrane. A glutathione-centered mechanism was further indicated by increased ER luminal glutathione levels in response to Ca2+ efflux. Inducible reduction of the ER lumen by GSH flux was independent of the Ca2+-binding chaperone calreticulin, which has previously been implicated in this process. However, opening the translocon channel by puromycin or addition of cyclosporine A mimicked the GSH-related effect of Ca2+ mobilization. While the action of puromycin was ascribable to Ca2+ leakage from the ER, the mechanism of cyclosporine A-induced GSH flux was independent of calcineurin and cyclophilins A and B and remained unclear.ConclusionsOur data strongly suggest that ER influx of cytosolic GSH, rather than inhibition of local oxidoreductases, is responsible for the reductive shift upon Ca2+ mobilization. We postulate the existence of a Ca2+- and cyclosporine A-sensitive GSH transporter in the ER membrane. These findings have important implications for ER redox homeostasis under normal physiology and ER stress.

Computed tomography-based hemodynamic index for aortic dissection

ObjectiveIn this study we aimed to propose a new computed tomography-based hemodynamic indicator to quantify the functional significance of aortic dissection and predict post intervention luminal remodeling. MethodsComputational hemodynamics and 3D structural analyses were conducted in 51 patients with type B aortic dissection, at initial presentation and at approximately 1 month, 3 months, and 1 year post intervention. A functional index was proposed on the basis of luminal pressure difference. Statistical relationships between the proposed indicator and longitudinal luminal development were analyzed. ResultsThe computed luminal pressure difference (true lumen pressure minus false lumen pressure) varied overall from positive to negative along the aorta. The first balance position at which the pressure difference equals 0 was proposed as the functional indicator. A more distally located first balance position indicated better functional status. Implantation of stent graft distally shifted this balance position. Patients with the balance position shifted out of the dissected region (43%) presented the highest functional improvement after intervention; whereas those with the balance position shifted to the abdominal region (25%) showed unsatisfactory results. The magnitude of distal shifting of the first balance position at 3 months post intervention was statistically related to the subsequent true lumen expansion and false lumen reduction. ConclusionsThe first balance position of luminal pressure difference quantified the hemodynamic status of the dissected aorta. The magnitude of distal shifting of the balance position after intervention was associated with functional improvement and might be used predict longitudinal aortic remodeling.

CRT-200.17 Impact of Race on Clinical Outcomes After Stent Revascularization for High-Grade Renal Artery Stenosis: A Single-Center Experience

The management of atherosclerotic renal artery stenosis can be challenging. Whether race has an impact on outcomes after revascularization is unknown. We report a single-center experience with patients with high-grade stenosis Patients with high-grade renal artery stenosis (a reduction in lumen

Incremental Image Noise Reduction in Coronary CT Angiography Using a Deep Learning-Based Technique with Iterative Reconstruction.

ObjectiveTo assess the feasibility of applying a deep learning-based denoising technique to coronary CT angiography (CCTA) along with iterative reconstruction for additional noise reduction.Materials and MethodsWe retrospectively enrolled 82 consecutive patients (male:female = 60:22; mean age, 67.0 ± 10.8 years) who had undergone both CCTA and invasive coronary artery angiography from March 2017 to June 2018. All included patients underwent CCTA with iterative reconstruction (ADMIRE level 3, Siemens Healthineers). We developed a deep learning based denoising technique (ClariCT.AI, ClariPI), which was based on a modified U-net type convolutional neural net model designed to predict the possible occurrence of low-dose noise in the originals. Denoised images were obtained by subtracting the predicted noise from the originals. Image noise, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively calculated. The edge rise distance (ERD) was measured as an indicator of image sharpness. Two blinded readers subjectively graded the image quality using a 5-point scale. Diagnostic performance of the CCTA was evaluated based on the presence or absence of significant stenosis (≥ 50% lumen reduction).ResultsObjective image qualities (original vs. denoised: image noise, 67.22 ± 25.74 vs. 52.64 ± 27.40; SNR [left main], 21.91 ± 6.38 vs. 30.35 ± 10.46; CNR [left main], 23.24 ± 6.52 vs. 31.93 ± 10.72; all p < 0.001) and subjective image quality (2.45 ± 0.62 vs. 3.65 ± 0.60, p < 0.001) improved significantly in the denoised images. The average ERDs of the denoised images were significantly smaller than those of originals (0.98 ± 0.08 vs. 0.09 ± 0.08, p < 0.001). With regard to diagnostic accuracy, no significant differences were observed among paired comparisons.ConclusionApplication of the deep learning technique along with iterative reconstruction can enhance the noise reduction performance with a significant improvement in objective and subjective image qualities of CCTA images.

Coronary Computed Tomographic Angiography Imaging as a Prognostic Indicator for Coronary Artery Disease: Data from a Lebanese Tertiary Center.

Background:Coronary artery disease (CAD) is a major cause of death and disability worldwide. Coronary computed tomographic angiography (CCTA) is a noninvasive imaging technique with a high negative predictive value (NPV). Most studies were done in developed countries, where the prevalence of CAD does not reflect the actual disease burden in developing countries, such as Lebanon.Methods:We retrospectively evaluated the prognostic value of CCTA in predicting acute myocardial events (AMEs) in 200 Lebanese patients. We determined if specific medical and radiological characteristics are linked with AME and looked for any association between the patient's medical risk factors and the type/location of detected atheromatous plaques. Patients' records were reviewed, and the follow-up period of 5–8 years ensued. Chi-square/Fisher test and Student's t-test were used, in addition to multinomial logistic regression to adjust for the confounding variables. P <0.05 was considered statistically significant.Results:Our study showed that CCTA had a NPV that reaches 97.9% in asymptomatic patients, a positive predictive value (PPV) of 76.4% for symptomatic patients, a sensitivity of 88.9%, and a specificity of 52.5%. AMEs were significantly increased in patients with a mixed plaque type and/or a moderate-to-severe lumen reduction on CCTA.Conclusions:CCTA is a sensitive modality for plaque detection and is found to have a remarkably high NPV for asymptomatic patients. A CCTA, along with a low pretest clinical probability of CAD, can be sufficient to rule out an AME for up to 8 years.

Surgical Strategies for Type B Aortic Dissection by Frozen Elephant Trunk.

The timing and choice of surgical method for type B aortic dissection, is still a topic of much debate. We performed total arch replacement using frozen elephant trunk (TAR-FET) as a means of preventing distant aortic events, such as retrograde type A aortic dissection (RTAD). We conducted analysis of 142 patients with acute type B dissection who were admitted between January of 2010 and July of 2017. Fifty-five cases required surgical intervention to treat enlargement of the false lumen diameter and ULP formation 2 weeks after the onset of symptoms. 17 TAR-FET were performed with a mean of 42±26 days period from onset to surgery. There were no complications of RTAD or paraplegic, and 90% of patient demonstrated aortic event free survival (5 years) and false lumen reduction ratio of 35%. Based on our analysis, using TAR-FET properly avoids serious complications like RTAD, and is a viable treatment option for type B dissection. (This is a translation of J Jpn Coll Angiol 2018; 58: 151–157.)

Anthonotha macrophylla P. Beauv (Caesalpiniaceae) aqueous extract exhibits antiestrogenic effects in vitro and in vivo.

Background Phytoestrogens are natural compounds known as natural selective estrogen receptor modulators used as alternatives against estrogen-dependent cancers. This study aims to evaluate the antiestrogenic effects of Anthonotha macrophylla, a plant used to treat cancer in Cameroon. Methods The estrogenic/antiestrogenic activities of A. macrophylla aqueous extract were evaluated in vitro using MCF-7 cell proliferation assay. Moreover, a classical uterotrophic test was carried out to evaluate the antiestrogenic effects of A. macrophylla in rats. Changes in the uterus, vagina, and mammary glands were used as endpoints of estrogenicity. Results Anthonotha macrophylla induced antiestrogenic effects in vitro at all the tested concentrations by inhibiting estradiol-induced MCF-7 cell proliferation (p < 0.001). In vivo, a coadministration of estradiol with A. macrophylla extract led to the decrease of uterine [150 (p < 0.05) and 300 (p < 0.01) mg/kg body weight (BW)] and vaginal [75 (p < 0.01) and 300 (p < 0.05) mg/kg BW] epithelial thickness. In addition, a reduction in the mammary gland acini lumen's diameter was also observed at 75 and 150 mg/kg. Gas chromatography-time-of-flight-mass spectrometry analysis showed that phenolic acid derivatives are present in A. macrophylla extract, which are well known to be endowed with estrogenic/antiestrogenic properties. The LD50 of A. macrophylla was estimated to be less than 2000 mg/kg. Conclusions Anthonotha macrophylla aqueous extract has antiestrogenic properties. This could promote more studies to explore its ability to prevent estrogen-dependent cancers.

Detecting Stent Geometry Changes After Venous Recanalisation Using Duplex Ultrasound

Introduction - Chronic obstruction of the deep venous system can lead to clinical symptoms known as the post-thrombotic syndrome (PTS). Endovenous revascularization has dominated as the therapy of choice in these patients during the last years. The aim of this study is to investigate the efficiency of duplex ultrasound (DUS) in monitoring the stent geometry during follow-ups. Methods - We retrospectively assessed all prospectively recorded data of patients treated by venous angioplasty and stenting from June 2012 to December 2016. All available gray-scale, color/power DUS images were reviewed retrospectively. The recorded stent diameter and area during the follow-up visits have been analyzed. DUS was used to measure the stent morphology as well as luminal area of the stent in different parts of the stented tract. Results - A total of 210 stents were placed in 137 limbs. DUS findings showed a decrease in area of stent in all patients (mean: 0.69 cm2). The mean percentage decrease of the stent area before the end of the primary patency was 36.52%. The only significant independent predictor of stent occlusion was the reduction of stent area over the time (OR: 0.910; CI: 0.832–0.997). Conclusion - DUS shows a sufficient diagnostic accuracy in the detection of stent changes and its patency. Findings of DUS are suggestive for existing discrepancy between diameters of the stent lumen in vitro and after deployment in all patients. However, stent occlusion appears to be related to reduction of stent lumen over the time rather than the pure percent of the stenosis. The degree of compression was measured with ellipse and calculated as:nominal area of stent (cm2) – measured area of stent (cm2) X 100 (%). The degree of compression was measured with ellipse and calculated as:nominal area of stent (cm2) – measured area of stent (cm2) X 100 (%).

Sevoflurane improves circulatory function and pulmonary fibrosis in rats with pulmonary arterial hypertension through inhibiting NF-κB signaling pathway.

The aim of this study was to explore the influences of sevoflurane inhalation therapy on circulation function and pulmonary fibrosis in rats with pulmonary arterial hypertension (PAH) and the nuclear factor-κB (NF-κB) signaling pathway. A total of 30 adult male Sprague-Dawley rats were randomly divided into three groups, including control group (CTL group, n=10), PAH group (n=10), and PAH + sevoflurane group (n=10) using a random number table. Subsequently, the pulmonary artery right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) were measured. Rats in PAH group were subcutaneously injected with 60 mg/kg monocrotaline once to establish the model of PAH. 28 d later, the differences in the morphology of pulmonary tissues and the protein expression levels of phosphorylated inhibitory κB (p-IκB), p-P65, P65, cyclin D1, proliferating cell nuclear antigen (PCNA) and tubulin among the three groups were analyzed via hematoxylin-eosin (HE) staining and Western blotting, respectively. Meanwhile, the messenger ribonucleic acid (mRNA) expression level of P65 was determined via Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR). Additionally, changes in the expression levels of Ki-67 and α-smooth muscle actin (α-SMA) in rat pulmonary tissues of the three groups were evaluated through immunohistochemistry. According to HE staining results, compared with CTL group, rats in PAH group exhibited significant thickening of the pulmonary artery wall, reduction of the vascular lumen, inflammatory cell infiltration, and thrombosis in some small arteries. This indicated that the PAH model was successfully established in rats. Compared with PAH group, PAH + sevoflurane group showed a significantly improved morphology of rat pulmonary tissues. Western blotting demonstrated that the protein expression levels of p-IκB, p-P65, and P65 in rat pulmonary tissues of PAH group were remarkably higher than CTL group (p<0.01). However, they were notably down-regulated in PAH + sevoflurane group when compared with those in PAH group (p<0.05). The above experimental results suggested that the NF-κB signaling pathway in pulmonary tissues of rats in PAH group was activated and was inhibited by sevoflurane. Subsequent RT-qPCR results indicated that no significant (N.S.) differences were observed in the mRNA level of P65 among the three groups. Compared with CTL group, PAH group showed significantly up-regulated levels of Ki-67 and α-SMA in rat pulmonary tissues (p<0.01). However, their expression levels were markedly reduced in PAH + sevoflurane group when compared with PAH group (p<0.05). Finally, the detection of pulmonary circulatory function-related indicators illustrated that RVSP and RVHI increased significantly in PAH group in comparison with CTL group. However, they declined remarkably in PAH + sevoflurane group when compared with those in PAH group (p<0.05). Sevoflurane down-regulates the levels of p-IκB, p-P65, and P65 to repress the activation of the NF-κB signaling pathway. This may reduce pulmonary fibrosis and ultimately prevent PAH.

Endovenöse Rekanalisationen von chronischen Beckenvenenverschlüssen

Approximately 60 % of patients with acute iliofemoral deep vein thrombosis recover without further symptoms. However, 40 % will have some degree of post-thrombotic syndrome (PTS) and 4 % will develop severe PTS. PTS is the most common complication; it reduces quality of life and increases DVT-related costs. The clinical symptoms and severity of PTS may vary; the most common symptoms include edema, pain, hyperpigmentation, lipodermatosclerosis, and ulceration. PTS is based on the principle of outflow obstruction, may be caused by venous hypertension, and may lead to valvular damage and venous reflux or insufficiency. A significant lumen reduction within the iliac vein system is defined by an aspect ratio ≥ 2. Recent technical developments and new dedicated venous stent techniques now give the opportunity to recanalize even complex venous outflow obstructions. First in man safety and efficacy data are very promising for the new dedicated venous stents, but long-term data are still missing.

Ex vivo evaluation of an atherosclerotic human coronary artery via histology and high-resolution hard X-ray tomography

Atherosclerotic arteries exhibit characteristic constrictions and substantial deviations from cylindrical shape. Therefore, determining the artery’s cross-section along the centerline is challenging, although high-resolution isotropic three-dimensional data are available. Herein, we apply high-resolution computed tomography in absorption and phase to a plaque-containing human artery post-mortem, through the course of the preparation stages for histology. We identify the impact of paraffin embedding and decalcification on the artery lumen. For automatic extraction of lumen’s cross-section along centerline we present a dedicated pipeline. Comparing fixated tissue before and after paraffin embedding gives rise to shape changes with lumen reduction to 50–80%. The histological slicing induces further deformations with respect to tomography. Data acquired after decalcification show debris unintentionally distributed within the vessel preventing the reliable automatic lumen segmentation. Comparing tomography of laboratory- and synchrotron-radiation-based X rays by means of joint histogram analysis leads us to conclude that advanced desktop tomography is capable of quantifying the artery’s lumen as an essential input for blood flow simulations. The results indicate that the most reliable lumen quantification is achieved by imaging the non-decalcified specimen fixed in formalin, using phase contrast modality and a dedicated processing pipeline. This study focusses on a methodology to quantitatively evaluate diseased artery segments post-mortem and provides unique structural parameters on the treatment-induced local shrinkage, which will be the basis of future studies on the flow in vessels affected by constrictions.

Longer 6-mm Diameter Stent Retrievers Are Effective for Achieving Higher First Pass Success with Fibrin-Rich Clots

First pass success (FPS) can be defined as in vitro retrieval of clot in a single pass during mechanical thrombectomy (MT) for acute large vessel occlusion (LVO). Despite advancements in MT technology, retrieval of fibrin-rich clots remains a challenge. Therefore, the effect of stent retriever length on FPS for fibrin-rich clots was investigated by using Solitaire^TM 6 × 40 versus 6 × 30 mm devices with a balloon guide catheter (BGC) or distal access catheter (DAC) and sheath, in an in vitro model of anterior circulation neurovascular anatomy. Additionally, vascular safety of the Solitaire^TM 6 × 40 versus 6 × 30 mm devices was evaluated in a porcine model for differences in: luminal thrombus, inflammation, endothelial coverage, fibrin deposits, smooth muscle cell loss, elastic lamina and adventitia disruption, intimal hyperplasia, and lumen reduction, at 0, 30, and 90 days post-treatment. In vitro overall FPS was measured as: Solitaire^TM 6 × 40 (95%) and Solitaire^TM 6 × 30 (67%). FPS for clot location in middle cerebral artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 100%; n = 8); (b) DAC with 088 sheath (6 × 40 mm: 83%; 6 × 30 mm: 33%; n = 12). FPS for clot location in internal carotid artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 80%; n = 11); (b) DAC with 088 sheath (6 × 40 mm: 100%; 6 × 30 mm: 67%; n = 10). Stent length had a significant effect (Fisher’s exact test; p < 0.05) on FPS. In vivo evaluation in the porcine model showed no difference in vascular safety parameters between the Solitaire^TM 6 × 40 and 6 × 30 mm devices (p > 0.05) at all time points in the study. Longer stent retrievers may be safe and effective in improving FPS for fibrin-rich clots in in vitro and in vivo models of LVO.

Utility of Multimodality Intravascular Imaging and the Local Hemodynamic Forces to Predict Atherosclerotic Disease Progression

ObjectivesThis study sought to examine the utility of multimodality intravascular imaging and of the endothelial shear stress (ESS) distribution to predict atherosclerotic evolution. BackgroundThere is robust evidence that intravascular ultrasound (IVUS)-derived plaque characteristics and ESS distribution can predict, with however limited accuracy, atherosclerotic evolution; nevertheless, it is yet unclear whether multimodality imaging and ESS mapping enable more accurate prediction of coronary plaque progression. MethodsA total of 44 patients admitted with a myocardial infarction that had successful revascularization and 3-vessel IVUS and optical coherence tomography (OCT) imaging at baseline and 13-month follow-up were included in the study. The IVUS data acquired at baseline in the nonculprit vessels were fused with x-ray angiography to reconstruct coronary anatomy and in the obtained models blood flow simulation was performed and the ESS was estimated. The baseline plaque characteristics and ESS distribution were used to identify predictors of disease progression: defined as a lumen reduction and an increase in plaque burden at follow-up. ResultsSeventy-three vessels were included in the final analysis. Baseline ESS and the IVUS-derived but not the OCT-derived plaque characteristics were independently associated with a decrease in lumen area and an increase in plaque burden. Low ESS (odds ratio: 0.45; 95% confidence interval: 0.28 to 0.71; p < 0.001) and plaque burden (odds ratio: 0.73; 95% confidence interval: 0.54 to 0.97; p = 0.030) were the only independent predictors of disease progression at follow-up. The accuracy of the IVUS-derived plaque characteristics in predicting disease progression did not improve when ESS (AUC: 0.824 vs. 0.847; p = 0.127) or when OCT variables and ESS (AUC: 0.842; p = 0.611) were added into the model. ConclusionsESS and OCT-derived variables did not improve the efficacy of IVUS in predicting disease progression. Further research is required to investigate whether multimodality imaging combined with ESS mapping will allow more reliable vulnerable plaque detection. (Comparison of Biomatrix Versus Gazelle in ST-Elevation Myocardial Infarction [STEMI] [COMFORTABLE]; NCT00962416)

Clinical Effects of Perioperative Selective Decontamination of the Digestive Tract (SDD) in Cardiac Surgery: A Propensity Score Matched Cohort Analysis

To determine the clinical effects of perioperative endotoxin reduction in the gut lumen in patients undergoing cardiac surgery with cardiopulmonary bypass. Retrospective cohort analysis with propensity score matching according to treatment group. Tertiary center for cardiopulmonary diseases and intensive care medicine. Included were patients who underwent cardiac surgery with cardiopulmonary bypass between 2008 and 2017. Excluded were readmitted patients. Endotoxin reduction in the gut lumen by ingestion of oral tobramycin 80 mg and polymyxin B 100 mg 4 times daily (TP) as part of selective digestive tract decontamination, which contains amphotericin B 500 mg as well. A total of 6,394 patients were included, of whom 2,044 patients were in the intervention group. A total of 835 patients received both pre- and postoperative TP (Pre+/Post+), and 1,165 patients received TP only postoperatively (Pre-/Post+). The control group, not treated with TP at any moment, consisted of 4,350 patients (Pre-/Post-). After matching, 652 Pre+/Post+ patients were compared with an equal number of controls (Pre-/Post-). Pre+/Post+ group did not do better for any clinical outcome. A total of 682 Pre+/Post+ patients matched with an equal number of Pre-/Post+ patients. The latter group had a 0.3 points higher mean Sequential Organ Failure Assessment score and in the regression analysis a significantly higher intensive care unit mortality but not hospital mortality. A significant reduction in length of stay and length of mechanical ventilation for the Pre+/Post+ group was shown compared with Pre-/Post+, but these differences can be explained by unbalanced differences in the severity of illness. Cardiosurgical patients who receive tobramycin and polymyxin orally preoperatively to reduce the gut endotoxin level do not expose convincing and relevant beneficial effects on clinical outcomes in this retrospective propensity score matching cohort study.

Hypertensive Neuropathy: A New Clinical Entity?

Hypertension is a main risk factor for stroke and vascular dementia and may cause important changes to the cerebrovascular tree, turning the brain more susceptible to infarcts, microaneurysms and ischemia. In spite of the well documented influence of hypertension on the brain, data on the sensitivity of peripheral nerves in hypertension is scarce. Our laboratory has been working for decades to help understanding how hypertension affects peripheral nerve morphology and function, using the spontaneously hypertensive rats (SHR) model. Spontaneously hypertensive rats (SHR), first inbred from Wistar Kyoto rats (WKY), are considered a good experimental model of human essential hypertension. The purpose of this study was to investigate the alterations on the morphology and morphometric data on sural, phrenic, vagus and recurrent laryngeal nerves of SHR, previous to the development of hypertension and with well‐established hypertension. Male and female SHR and normotensive WKY rats aged 5, 8 and 20 weeks (N = 6 in each group) were investigated. After arterial pressure and heart rate recordings in anesthetized animals, right and left sural, vagus, phrenic and recurrent laryngeal nerves were removed and prepared for epoxy resin embedding and light microscopy. Morphometric analysis was performed with the aid of computer software, and took into consideration the fascicle area and diameter, as well as myelinated fiber number, density, area and diameter. Nerves from young animals did not show differences between sides and genders. Significant differences were observed for the myelinated fiber number and density, comparing different genders of WKY and SHR in all nerves. Also, significant differences for the morphological (thickening of the endoneural blood vessel walls and lumen reduction) and morphometric (myelinated fibers diameter and G ratio) parameters of myelinated fibers were identified in nerves from adult hypertensive animals. Morphological exam of the myelinated fibers suggested the presence of a neuropathy due to hypertension in both SHR genders. These results indicate that hypertension altered important morphometric parameters related to nerve conduction in hypertensive animals. Moreover the comparison between males and females of WKY and SHR showed that the morphological and morphometric alterations due to hypertension are not gender related. The presence of a so called “hypertensive neuropathy” is documented with endoneural vascular lesions, axonal atrophy and loss of small myelinated fibers.Support or Funding InformationSupport: CNPq, FAPESP and FAEPAThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.