[Patient education in chronic polyarthritis. 3. Intermediate results of a prospective, controlled study of the effectiveness and side effects of patient seminars for polyarthritis patients]

Tortuosity of the Internal Carotid Artery and Its Clinical Significance in the Development of Aneurysms

Tortuosity of blood vessels is a common angiographic finding that may indicate systemic disease and can be correlated with vascular pathologies. In this work, we determined whether patients with and without internal carotid artery (ICA) aneurysm presented with differences in its tortuosity descriptors. We retrospectively analysed data of 298 patients hospitalized between January 2014 and June 2018. For each patient's imaging data, we extracted a curve representing the ICA course and measured its Relative Length (RL), Sum of Angle Metrics (SOAM), Product of Angle Distance (PAD), Triangular Index (TI), and Inflection Count Metrics (ICM). We found that patients with an ICA aneurysm had significantly lower RL (0.46 ± 0.19 vs. 0.51 ± 0.17; p = 0.023) and significantly higher SOAM (0.39 ± 0.21 vs. 0.32 ± 0.21 p = 0.003), PAD (0.38 ± 0.19 vs. 0.32 ± 0.21; p = 0.011), TI (0.30 ± 0.11 vs. 0.27 ± 0.14; p = 0.034), and ICM (0.30 ± 0.16 vs. 0.22 ± 0.12; p < 0.001). We found that that patients who presented with a subarachnoid hemorrhage had significantly higher PAD (0.46 ± 0.22 vs. 0.35 ± 0.20; p = 0.024). In conclusion, higher tortuosity of ICA is associated with ICA aneurysm presence.

Validity of tortuosity severity index in chest pain patients with abnormal exercise test and normal coronary angiography

BACKGROUND

Coronary tortuosity (CT) had different definitions and scores in literature with unclear pathophysiological impact.

OBJECTIVES

To study degree of CT and it's relation to ischemic changes in patients with angina but normal coronary angiography (CA).

METHODS

We conducted a prospective study at University hospitals between May 2016 and January 2017. We included 200 consecutive patients who underwent CA due to chest pain assumed to be of cardiac origin, and their CA was normal (no diameter stenosis >30%, nor myocardial bridging). Patients were prospectively divided into 2 groups based on the presence (n = 113) or absence (n = 87) of ischemic changes during stress study and compared for clinical, echocardiographic and CA characteristics. A newly proposed Tortuosity Severity Index (TSI) was developed into significant (mild/moderate CT with more than 4 curvatures in total, or severe/extreme CT with any number of curvatures) or not significant TSI (mild CT with curvatures less than or equal to 4 curvatures in total).

RESULTS

Patients with ischemic changes had the highest rate of CT (76.5 vs 18%, p = 0.004) compared to those without. CT mostly affects the left anterior descending (LAD) coronary artery in mid and distal segments. Females, elderly, and hypertensives with left ventricular hypertrophy were strongly related to CT. Multivariate logistic regression analysis identified CT with significant TSI as the only predictor of ischemic changes in these patients (OR = 6.2, CI = 2.5-15.3, P = <0.001).

CONCLUSIONS

Coronary tortuosity is a strong predictor of anginal pain among patients with normal CA, despite positive stress study. This finding is more pronounced among elderly, hypertensive female patients.

Retinal vascular tortuosity assessment: inter-intra expert analysis and correlation with computational measurements

Background

The retinal vascular tortuosity can be a potential indicator of relevant vascular and non-vascular diseases. However, the lack of a precise and standard guide for the tortuosity evaluation hinders its use for diagnostic and treatment purposes. This work aims to advance in the standardization of the retinal vascular tortuosity as a clinical biomarker with diagnostic potential, allowing, thereby, the validation of objective computational measurements on the basis of the entire spectrum of the expert knowledge.

Methods

This paper describes a multi-expert validation process of the computational vascular tortuosity measurements of reference. A group of five experts, covering the different clinical profiles of an ophthalmological service, and a four-grade scale from non-tortuous to severe tortuosity as well as non-tortuous / tortuous and asymptomatic / symptomatic binary classifications are considered for the analysis of the the multi-expert validation procedure. The specialists rating process comprises two rounds involving all the experts and a joint round to establish consensual rates. The expert agreement is analyzed throughout the rating procedure and, then, the consensual rates are set as the reference to validate the prognostic performance of four computational tortuosity metrics of reference.

Results

The Kappa indexes for the intra-rater agreement analysis were obtained between 0.35 and 0.83 whereas for the inter-rater agreement in the asymptomatic / symptomatic classification were between 0.22 and 0.76. The Area Under the Curve (AUC) for each expert against the consensual rates were placed between 0.61 and 0.83 whereas the prognostic performance of the best objective tortuosity metric was 0.80.

Conclusions

There is a high inter and intra-rater variability, especially for the case of the four grade scale. The prognostic performance of the tortuosity measurements is close to the experts’ performance, especially for Grisan measurement. However, there is a gap between the automatic effectiveness and the expert perception given the lack of clinical criteria in the computational measurements.

The effect of age and gender on tortuosity of the descending thoracic Aorta

BACKGROUND

To study the effect of age and gender on tortuosity of the descending thoracic aorta, and to evaluate inter-observer agreement of tortuosity index (TI) measurements.

METHODS

Contrast-enhanced CT scans of 182 patients were analyzed by an experienced radiologist using routine 3D imaging software. The descending aorta was defined by proximal and distal endpoints. The software generated centerline length, and straight line distance between the 2 endpoints were measured. TI was calculated as: [centerline length / straight line distance -1] * 100. Impact of age on TI of the descending aorta was assessed using linear regression in both genders. To assess inter-observer agreement; TI measurements of 50 cases were repeated by 3 other independent readers.

RESULTS

The mean (±SD) TI was 8.3 ± 2.6 in men and 8.9 ± 3 in women, with no significant difference between the 2 genders, p = 0.208. Moderate positive correlation was observed between TI and age (r = 0.566, p < 0.00001 and r = 0.569, p < 0.00001 in men and women, respectively). The 10-year-percent change was higher in women than men (13.3% and 9.5%, respectively). Inter-observer agreement for TI was good, intra-class correlation coefficient was 0.84 (95% CI: 0.76-0.89, p < 0.0001). Centerline length was poorly correlated to age (r = 0.248, p = 0.048 in men and r = 0.369, p < 0.001 in women). Body-surface-area-indexed centerline length was not significantly correlated to age (p = 0.948).

CONCLUSIONS

Tortuosity of the descending aorta increases with age in both genders. TI has acceptable inter-observer agreement and was better correlated to age than centerline length measurements.

A Serpiginous Pericallosal Anterior Cerebral Artery

The anterior cerebral artery (ACA) is a unique artery with many important variations with substantial clinical significance. Tortuous intracranial arteries usually occur in basilar, communicating, anterior, posterior cerebral arteries and in the white matter arterioles. This could happen for many reasons including but not limited to ageing, hypertension, patients with Moyamoya disease, congenital malformation, or increased flow associated with elastin degradation. While dolichoectasia of the ACA has been described even in children, to our knowledge, a serpiginous ACA without ectasia has not been reported, especially in the pediatric population.

Advanced Optical Coherence Tomography Angiography Analysis of Age-related Macular Degeneration Complicated by Onset of Unilateral Choroidal Neovascularization

PURPOSE

To analyze optical coherence tomography angiography (OCTA) quantitative features in patients affected by new-onset choroidal neovascularization (CNV) in 1 eye and early/intermediate age-related macular degeneration (AMD) in the fellow eye.

DESIGN

Case-control study.

METHODS

Setting: Clinical practice.

STUDY POPULATION

Thirty patients and 30 age-matched controls.

OBSERVATION PROCEDURES

Both cohorts underwent complete ophthalmologic examination, including best-corrected visual acuity (BCVA) measurement, biomicroscopy, fluorescein angiography (FA) and indocyanine green angiography (ICGA) examination, optical coherence tomography, and OCTA scans. The 1-way a test with Bonferroni correction was used to assess statistical significance and Tau Kendall's correlation analysis was performed.

MAIN OUTCOME MEASURES

BCVA, choroidal thickness, vessel density, vessel tortuosity, vessel dispersion. and vessel rarefaction.

RESULTS

Mean BCVA was 20/32 for CNV eyes and 20/20 for both fellow and control eyes. Choroidal thickness was 190.33 ± 63.98 μm for CNV eyes, 216.83 ± 50.31 μm for fellow eyes, and 310.52 ± 27.13 μm for controls. The quantitative analysis of retinal vessels revealed significant alterations, especially in the deep capillary plexus and radial peripapillary capillaries, both in CNV and in fellow eyes, compared with controls. In particular, decreased vessel density and tortuosity and increased dispersion and rarefaction were found. Several significant correlations were also found among the quantitative parameters adopted.

CONCLUSIONS

New postprocessing OCTA parameters are able to detect deep retinal vascular alterations quantitatively, in both CNV-affected and fellow eyes of patients with new-onset CNV. Further investigations are warranted in order to explore the validity of these new approaches on follow-up.

Analysis of Anterior Cerebral Artery Tortuosity: Association with Anterior Communicating Artery Aneurysm Rupture

BACKGROUND

Many researchers have found a correlation between tortuous arteries and development of aneurysms in cerebral arteries. However, there are no studies analyzing the impact of tortuosity on risk of subarachnoid hemorrhage (SAH) occurrence. Therefore, we decided to determine whether tortuosity of the anterior cerebral artery can be related to the rupture of anterior communicating artery aneurysm and to severity and treatment outcome of SAH.

METHODS

We retrospectively analyzed anterior cerebral artery anatomy of 121 patients with anterior communicating artery aneurysms. From patients' medical records, we obtained their history including previous and current diseases and medications. For each patient we calculated relative length, sum of angle metrics, triangular index, product of angle distance, and inflection count metrics.

RESULTS

Patients with SAH had significantly higher relative length (0.70 ± 0.19 vs. 0.63 ± 0.22; P = 0.03) and significantly lower inflection count metrics (0.10 ± 0.08 vs. 0.16 ± 0.19; P < 0.01), respectively. In multivariate logistic regression analysis, after adjustment of all possible confounders, diabetes mellitus (odds ratio [OR], 0.154; 95% confidence interval [CI], 0.032-0.553; P < 0.01) and higher inflection count metrics (OR, 0.604; 95% CI, 0.357-0.909; P = 0.042) remained independently associated with lower risk of SAH. We also found an independent correlation between aneurysm dome size (R = -0.289; P = 0.02) and triangular index (R = 0.273; P = 0.03) and Glasgow Coma Scale score on admission.

CONCLUSIONS

Higher anterior cerebral artery tortuosity might be a protective factor against anterior communicating artery aneurysm rupture.

Reasons for Reperfusion Failures in Stent-Retriever-Based Thrombectomy: Registry Analysis and Proposal of a Classification System

BACKGROUND AND PURPOSE

In 5%-10% of patients with acute ischemic stroke with an intention to treat with mechanical thrombectomy, no reperfusion can be achieved (Thrombolysis in Cerebral Infarction score = 0/1). Purpose of this analysis was a systematic assessment of underlying reasons for reperfusion failures.

MATERIALS AND METHODS

An intention-to-treat single-center cohort (n = 592) was re-evaluated for all patients in whom no reperfusion could be achieved (n = 63). Baseline characteristics of patients were compared between patients with and without reperfusion failures. After qualitative review of all cases with reperfusion failures, a classification system was proposed and relative frequencies were reported. In a second step, occurrence of delayed recanalization at 24 hours after reperfusion failure and dependency on IV-tPA were evaluated.

RESULTS

In 63/592 patients with an intention to perform stent-retriever thrombectomy, no reperfusion was achieved (TICI 0/1, 10.6%, 95% CI, 8.2%-13.1%). Older patients (adjusted OR per yr = 1.03; 95% CI, 1.01-1.05) and patients with M2 occlusion (adjusted OR = 3.36; 95% CI, 1.82-6.21) were at higher risk for reperfusion failure. In most cases, no reperfusion was a consequence of technical difficulties (56/63, 88.9%). In one-third of these cases, reperfusion failures were due to the inability to reach the target occlusion (20/63, 31.7%), while "stent-retriever failure" occurred in 39.7% (25/63) of patients. Delayed recanalization was very rare (18.2%), without dependence on IV-tPA pretreatment status.

CONCLUSIONS

Reasons for reperfusion failure in stent-retriever thrombectomy are heterogeneous. The failure to establish intracranial or cervical access is almost as common as stent-retriever failure after establishing intracranial access. Systematic reporting standards of reasons may help to further estimate relative frequencies and thereby guide priorities for technical development and scientific effort.

Intracranial Arterial Tortuosity According to the Characteristics of Intracranial Aneurysms

OBJECTIVE

Intracranial aneurysm (IA) is the leading cause of subarachnoid hemorrhage. The pathomechanisms of IA are poorly understood but can be related to arterial tortuosity resulting from underlying systemic factors leading to arterial wall weakening. We aimed to analyze the tortuosity of the intracranial artery in a cohort with IA, hypothesizing that the tortuosity of intracranial arteries differs depending on the characteristics of the IA.

METHODS

Patients with saccular IA were consecutively enrolled. Clinical factors and vascular tortuosity of the right and left middle cerebral arteries and basilar artery (BA) of all patients with IA were compared according to the characteristics of the IA: 1) ruptured versus unruptured, 2) multiple versus single, and 3) large (>5 cm) versus small (≤5 cm). Unruptured IAs were comparatively analyzed according to aneurysm size and aspect ratio, whereas ruptured IAs were analyzed according to aneurysm size.

RESULTS

Two hundred eighty-five patients were enrolled (mean age, 59 years; 71.2% women). The tortuosity of the BA was higher in the large IA group (5.63 ± 6.26; n = 133; P = 0.009), large unruptured IA group (6.64 ± 6.32; n = 53; P = 0.039), and large ruptured IA group (5.50 ± 6.52; n = 80; P = 0.033) compared with the small IA, small unruptured IA, and small ruptured IA group. In multivariate analysis, increased BA tortuosity was significantly associated with large IAs (β = 1.066; P = 0.008), unruptured large IAs (β = 1.077; P = 0.033), and ruptured large IAs (β = 1.086; P = 0.025).

CONCLUSIONS

The BA tortuosity was higher in patients with large IAs, which may represent an imaging biomarker of aneurysm growth.

Two-dimensional speckle-tracking echocardiographic evaluation of the longitudinal deformation of the left ventricular myocardium in patients with severe coronary artery tortuosity

PURPOSE

Coronary artery tortuosity (CAT) is an anatomical condition in which epicardial coronary arteries have abnormal curves or spiral courses. Although correlated with higher rates of positive stress test, its effects on the myocardial function remain to be clearly defined.

METHODS

We included in this cross-sectional study and evaluated with 2D speckle-tracking echocardiography 40 consecutive patients admitted to our hospital for selective coronary angiography which showed severe CAT without significant epicardial coronary artery stenosis, and 40 consecutive subjects matched for age, hypertension, and diabetes in whom selective coronary angiography showed neither CAT nor significant epicardial coronary artery stenosis.

RESULTS

Systolic strain, strain rate, and early and late diastolic strain rates were not significantly different between the 2 groups, even after adjustment for potential confounding variables.

CONCLUSION

The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.

"Lambda-wave" ST-elevation is associated with severe prognosis in stress (takotsubo) cardiomyopathy

BACKGROUND

Persistent ST-segment elevation in acute coronary syndrome is associated with both short and long-term complications. By contrast, there is limited information about ST-elevation and its evolution during takotsubo (stress) cardiomyopathy (TTC).

AIM

To evaluate whether persistent downsloping ST-elevation in the early stages of TTC might correlate with short and long-term clinical events.

METHODS

One-hundred fifty-eight consecutive subjects with TTC were prospectively enrolled and assessed by electrocardiogram. Patients were classified in two groups according to the presence of downsloping ST-elevation ≥5 mm lasting at least 24 hr ("lambda-wave" ST-elevation group vs. without downsloping ST-elevation) in at least one/two contiguous leads.

RESULTS

Five (3.2%) patients, all female with a mean left ventricular ejection fraction 32 ± 5%, were included in the lambda-wave ST-elevation group. These patients were characterized by a higher prevalence of physical stressor (100% vs. 49%, p = 0.04) and higher admission and peak levels of troponin-I levels during hospitalization. Peak of ST-elevation in the lambda-wave ST-elevation group was reached 6 hr after admission and gradually decreased after 24 hr. In-hospital complications were observed in all the patients presenting lambda ST-elevation (100% vs. 23%, p = 0.03, OR: 29.1, p = 0.04); one patient presented endoventricular thrombosis and two died of cardiogenic shock. At long-term follow-up (mean 443 days), adverse events were observed in 80% of patients with lambda-wave ST-elevation (RR of adverse events at follow-up 32, p < 0.01).

CONCLUSION

Persistent downsloping lambda-wave ST-elevation during the acute phase of stress cardiomyopathy may be associated with a higher risk of adverse events at short and long-term follow-up.

Detection of Diabetes by Macrovascular Tortuosity of Superior Bulbar Conjunctiva

More than 8% of world population have diabetes which causes long term complications such as retinopathy, neuropathy, nephropathy and foot ulcers. Growing patient numbers has prompted large scale screening methods to detect early symptoms of diabetes (rather than elevated blood glucose levels which is a late symptom). Vascular tortuosity (twisted and curved nature of blood vessels) in retinal fundus images has proven to reflect the effect of diabetes on macrovasculature. However, large scale patient screening using retinal fundus images has limitations due to the requirement of a retinal camera. Therefore, we hypothesize that the vasculature of superior bulbar conjunctiva which could be captured using a regular camera could be used to measure tortuosity instead of retinal fundus images enabling mass screening.To test this hypothesis, a total of 168 scleral images were acquired from 50 healthy subjects and 34 diabetic patients using a digital camera. The sclera region was segmented using Chan-Vese algorithm and macrovasculature of superior bulbar conjunctiva was segmented using B-COSFIRE filters. Results revealed that the superior bulbar conjunctival macrovascular tortuosity of diabetic patients was significantly less than that of non-diabetic group (p-value =0.015). A similar result was yielded (p-value =0.049) from a group of participants who were less than 40 years old which excluded the age related variation of tortuosity.

Retinal artery/vein classification using genetic-search feature selection

BACKGROUND AND OBJECTIVES

The automatic classification of retinal blood vessels into artery and vein (A/V) is still a challenging task in retinal image analysis. Recent works on A/V classification mainly focus on the graph analysis of the retinal vasculature, which exploits the connectivity of vessels to improve the classification performance. While they have overlooked the importance of pixel-wise classification to the final classification results. This paper shows that a complicated feature set is efficient for vessel centerline pixels classification.

METHODS

We extract enormous amount of features for vessel centerline pixels, and apply a genetic-search based feature selection technique to obtain the optimal feature subset for A/V classification.

RESULTS

The proposed method achieves an accuracy of 90.2%, the sensitivity of 89.6%, the specificity of 91.3% on the INSPIRE dataset. It shows that our method, using only the information of centerline pixels, gives a comparable performance as the techniques which use complicated graph analysis. In addition, the results on the images acquired by different fundus cameras show that our framework is capable for discriminating vessels independent of the imaging device characteristics, image resolution and image quality.

CONCLUSION

The complicated feature set is essential for A/V classification, especially on the individual vessels where graph-based methods receive limitations. And it could provide a higher entry to the graph-analysis to achieve a better A/V labeling.

Aging-associated changes in cerebral vasculature and blood flow as determined by quantitative optical coherence tomography angiography

Normal aging is associated with significant alterations in brain's vascular structure and function, which can lead to compromised cerebral circulation and increased risk of neurodegeneration. The in vivo examination of cerebral blood flow (CBF), including capillary beds, in aging brains with sufficient spatial detail remains challenging with current imaging modalities. In the present study, we use 3-dimensional (3-D) quantitative optical coherence tomography angiography (OCTA) to examine characteristic differences of the cerebral vasculatures and hemodynamics at the somatosensory cortex between old (16 months old) and young mice (2 months old) in vivo. The quantitative metrics include cortical vascular morphology, CBF, and capillary flow velocity. We show that compared with young mice, the pial arterial tortuosity increases by 14%, the capillary vessel density decreases by 15%, and the CBF reduces by 33% in the old mice. Most importantly, changes in capillary velocity and heterogeneity with aging are quantified for the first time with sufficiently high statistical power between young and old populations, with a 21% (p < 0.05) increase in capillary mean velocity and 19% (p ≤ 0.05) increase in velocity heterogeneity in the latter. Our findings through noninvasive imaging are in line with previous studies of vascular structure modification with aging, with additional quantitative assessment in capillary velocity enabled by advanced OCTA algorithms on a single imaging platform. The results offer OCTA as a promising neuroimaging tool to study vascular aging, which may shed new light on the investigations of vascular factors contributing to the pathophysiology of age-related neurodegenerative disorders.

Relationship between the geometry patterns of vertebrobasilar artery and atherosclerosis

Background

The plaques at the dorsal or lateral wall of basilar artery (BA) are associated with pontine infarcts. We sought to explore the correlations between vertebrobasilar artery geometry and BA plaque locations.

Methods

We retrospectively analyzed the imaging and clinical data of 84 patients with BA atherosclerosis. On three-dimensional time-of-flight images, a side to side diameter difference of bilateral vertebral artery (VA) and BA bending were assessed. The vertebrobasilar artery geometry was qualitatively classified into four basic configurations: Walking, Tuning Fork, Dominant-Lambda, and Hypoplasia-Lambda. On high-resolution magnetic resonance imaging, the plaques were categorized based on the involvement of the ventral, dorsal, or lateral sides of BA wall. The relationships between vertebrobasilar artery geometry parameters and plaque locations were analyzed.

Results

Left VA dominance was identified in 28(33%) patients, and right VA dominance in 22(26%) patients. BA bending were detected in 49 patients. There were no significant correlations between the diameter difference/ratio of VA diameters and plaque locations, or between BA bending and plaque locations. BA plaques were evenly distributed in the vertebrobasilar arteries with Tuning Fork and Dominant-Lambda configurations. In Hypoplasia-Lambda group, however, plaques were more frequently located at the dorsal wall (58.57%) than at the ventral (14.43%) and lateral wall (26.71%; P = 0.001). In Walking group, the plaques more likely occurred at the lateral (49.79%) and dorsal (35.07%) wall than at the ventral wall (14.86%, P = 0.02).

Conclusions

The geometric configurations of vertebrobasilar artery strongly influence the BA plaque locations. Further prospective studies are warranted to testify whether Hypoplasia-Lambda and Walking configurations are independent risk factors for pontine infarcts.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1084-6) contains supplementary material, which is available to authorized users.

Two-Stage Motion Correction for Super-Resolution Ultrasound Imaging in Human Lower Limb

The structure of microvasculature cannot be resolved using conventional ultrasound (US) imaging due to the fundamental diffraction limit at clinical US frequencies. It is possible to overcome this resolution limitation by localizing individual microbubbles through multiple frames and forming a superresolved image, which usually requires seconds to minutes of acquisition. Over this time interval, motion is inevitable and tissue movement is typically a combination of large- and small-scale tissue translation and deformation. Therefore, super-resolution (SR) imaging is prone to motion artifacts as other imaging modalities based on multiple acquisitions are. This paper investigates the feasibility of a two-stage motion estimation method, which is a combination of affine and nonrigid estimation, for SR US imaging. First, the motion correction accuracy of the proposed method is evaluated using simulations with increasing complexity of motion. A mean absolute error of 12.2 was achieved in simulations for the worst-case scenario. The motion correction algorithm was then applied to a clinical data set to demonstrate its potential to enable in vivo SR US imaging in the presence of patient motion. The size of the identified microvessels from the clinical SR images was measured to assess the feasibility of the two-stage motion correction method, which reduced the width of the motion-blurred microvessels to approximately 1.5-fold.

Late neuroprogenitors contribute to normal retinal vascular development in a Hif2a-dependent manner

In the adult central nervous system, endothelial and neuronal cells engage in tight cross-talk as key components of the so-called neurovascular unit. Impairment of this important relationship adversely affects tissue homeostasis, as observed in neurodegenerative conditions including Alzheimer's and Parkinson's disease. In development, the influence of neuroprogenitor cells on angiogenesis is poorly understood. Here, we show in mouse that these cells interact intimately with the growing retinal vascular network, and we identify a novel regulatory mechanism of vasculature development mediated by hypoxia-inducible factor 2a (Hif2a). By Cre-lox gene excision, we show that Hif2a in retinal neuroprogenitor cells upregulates the expression of the pro-angiogenic mediators vascular endothelial growth factor and erythropoietin, whereas it locally downregulates the angiogenesis inhibitor endostatin. Importantly, absence of Hif2a in retinal neuroprogenitor cells causes a marked reduction of proliferating endothelial cells at the angiogenic front. This results in delayed retinal vascular development, fewer major retinal vessels and reduced density of the peripheral deep retinal vascular plexus. Our findings demonstrate that retinal neuroprogenitor cells are a crucial component of the developing neurovascular unit.

Fractal dimension and lacunarity analysis of retinal microvascular morphology in hypertension and diabetes

Hypertension and diabetes mellitus represent modifiable risk factors for vascular disease. They cause microvascular remodeling, and ultimately result in end-organ damage. Therefore, development of methods for noninvasive quantification of the effects of hypertension and diabetes mellitus on microvasculature is of paramount importance. The two goals of the study were: 1) to characterize the geometric complexity and inhomogeneity of retinal vasculature in hypertensive retinopathy (HR) and in proliferative diabetic retinopathy (PDR) by using box counting fractal dimension and lacunarity analysis, and 2) to determine if the combination of these two parameters can be used to describe differences in the vascular tree geometry between HR and PDR. The extended set of retinal images from the publicly available STARE database was manually segmented by our expert, validated, and made available for other researchers to use. The healthy retinal vascular network has a higher complexity (fractal dimension) compared to that in HR and in PDR. However, there is no difference in microvascular complexity between HR and PDR. The inhomogeneity of the retinal microvascular tree (lacunarity) was higher in PDR compared to HR. Lacunarity and fractal dimension together quantitatively characterize microvascular geometry in the retina with higher specificity than fractal analysis alone.

Fluid-structure interaction modeling of aneurysmal arteries under steady-state and pulsatile blood flow: a stability analysis

Tortuous aneurysmal arteries are often associated with a higher risk of rupture but the mechanism remains unclear. The goal of this study was to analyze the buckling and post-buckling behaviors of aneurysmal arteries under pulsatile flow. To accomplish this goal, we analyzed the buckling behavior of model carotid and abdominal aorta with aneurysms by utilizing fluid-structure interaction (FSI) method with realistic waveforms boundary conditions. FSI simulations were done under steady-state and pulsatile flow for normal (1.5) and reduced (1.3) axial stretch ratios to investigate the influence of aneurysm, pulsatile lumen pressure and axial tension on stability. Our results indicated that aneurysmal artery buckled at the critical buckling pressure and its deflection nonlinearly increased with increasing lumen pressure. Buckling elevates the peak stress (up to 118%). The maximum aneurysm wall stress at pulsatile FSI flow was (29%) higher than under static pressure at the peak lumen pressure of 130 mmHg. Buckling results show an increase in lumen shear stress at the inner side of the maximum deflection. Vortex flow was dramatically enlarged with increasing lumen pressure and artery diameter. Aneurysmal arteries are more susceptible than normal arteries to mechanical instability which causes high stresses in the aneurysm wall that could lead to aneurysm rupture.

Hydrogel microfibers with perfusable folded channels for tissue constructs with folded morphology

Perfusable microfibers with folded channels are generated to fabricate small intestine and skeletal muscle constructs for tissue engineering.

Artefactual angulated lesion on angiography: A case report and review of literature

We present a case of a patient who presented with chest pain, and on diagnostic coronary angiography appeared to have a grossly angulated yet significant coronary stenosis. This was proven to be an artefactual appearance on further assessment with intravascular ultrasound imaging. We describe the causes and associations of coronary tortuosity with other arteriopathy, and highlight challenges in the interpretation of tortuous vessels to accurately assess luminal narrowing and suitability for coronary intervention. We describe a case of artefactual coronary stenosis, and its thorough assessment with intravascular ultrasound. A literature review describes the pathogenesis of coronary tortuosity, and links with other cardiovascular disease. Readers will gain an understanding of the challenge in determining the severity of luminal stenosis based on coronary angiography alone in tortuous coronary anatomy, the use of intravascular ultrasound in this setting, and the allied vasculopathies of interest.

Autism risk classification using placental chorionic surface vascular network features

Background

Autism Spectrum Disorder (ASD) is one of the fastest-growing developmental disorders in the United States. It was hypothesized that variations in the placental chorionic surface vascular network (PCSVN) structure may reflect both the overall effects of genetic and environmentally regulated variations in branching morphogenesis within the conceptus and the fetus’ vital organs. This paper provides sound evidences to support the study of ASD risks with PCSVN through a combination of feature-selection and classification algorithms.

Methods

Twenty eight arterial and 8 shape-based PCSVN attributes from a high-risk ASD cohort of 89 placentas and a population-based cohort of 201 placentas were examined for ranked relevance using a modified version of the random forest algorithm, called the Boruta method. Principal component analysis (PCA) was applied to isolate principal effects of arterial growth on the fetal surface of the placenta. Linear discriminant analysis (LDA) with a 10-fold cross validation was performed to establish error statistics.

Results

The Boruta method selected 15 arterial attributes as relevant, implying the difference in high and low ASD risk can be explained by the arterial features alone. The five principal features obtained through PCA, which accounted for about 88% of the data variability, indicated that PCSVNs associated with placentas of high-risk ASD pregnancies generally had fewer branch points, thicker and less tortuous arteries, better extension to the surface boundary, and smaller branch angles than their population-based counterparts.

Conclusion

We developed a set of methods to explain major PCSVN differences between placentas associated with high risk ASD pregnancies and those selected from the general population. The research paradigm presented can be generalized to study connections between PCSVN features and other maternal and fetal outcomes such as gestational diabetes and hypertension.

Lack of chronic neuroinflammation in the absence of focal hemorrhage in a rat model of low-energy blast-induced TBI

Blast-related traumatic brain injury (TBI) has been a common cause of injury in the recent conflicts in Iraq and Afghanistan. Blast waves can damage blood vessels, neurons, and glial cells within the brain. Acutely, depending on the blast energy, blast wave duration, and number of exposures, blast waves disrupt the blood-brain barrier, triggering microglial activation and neuroinflammation. Recently, there has been much interest in the role that ongoing neuroinflammation may play in the chronic effects of TBI. Here, we investigated whether chronic neuroinflammation is present in a rat model of repetitive low-energy blast exposure. Six weeks after three 74.5-kPa blast exposures, and in the absence of hemorrhage, no significant alteration in the level of microglia activation was found. At 6 weeks after blast exposure, plasma levels of fractalkine, interleukin-1β, lipopolysaccharide-inducible CXC chemokine, macrophage inflammatory protein 1α, and vascular endothelial growth factor were decreased. However, no differences in cytokine levels were detected between blast-exposed and control rats at 40 weeks. In brain, isolated changes were seen in levels of selected cytokines at 6 weeks following blast exposure, but none of these changes was found in both hemispheres or at 40 weeks after blast exposure. Notably, one animal with a focal hemorrhagic tear showed chronic microglial activation around the lesion 16 weeks post-blast exposure. These findings suggest that focal hemorrhage can trigger chronic focal neuroinflammation following blast-induced TBI, but that in the absence of hemorrhage, chronic neuroinflammation is not a general feature of low-level blast injury.

Combined CT angiography of the aorta and craniocervical artery: a new imaging protocol for assessment of acute type A aortic dissection

Background

To investigate the feasibility of combined computed tomography angiography (CTA) of the aorta and craniocervical artery in acute type A aortic dissection (ATAAD) and the value of incremental craniocervical information.

Methods

Combined CTA of head, neck and aorta was performed in patients with suspected aortic dissection and 243 ATAAD patients were analyzed. The image quality and radiation dose were assessed. Valuable craniocervical CTA findings were determined for further surgical analysis.

Results

The mean dose-length product (DLP) was 314.11±29.31 mGy.cm. The image quality of craniocervical arteries were 100% diagnostic. Intimal flap involving carotid arteries was detected in 47% of patients, and significant stenosis of true lumen was observed in 60% of common carotid arteries (CCAs). Hypodensity and hypoplasia/occlusion of carotid arteries were also detected and apprised surgeons. The tortuosity of carotid artery was found in 90.9% of patients. Bilateral antegrade selective cerebral perfusion (ASCP) was performed in 21.1% of aortic arch surgery based on 7 hemodynamic variation types of the circle of Willis (CW) determined by cranial CTA information.

Conclusions

A combined CTA of head, neck and aorta is feasible with low radiation dose and diagnostic image quality. Incremental information on craniocervical pathology and anatomy may be useful for surgery repair of ATAAD.

Imaging in cutis laxa syndrome caused by a dominant negative ALDH18A1 mutation, with hypotheses for intracranial vascular tortuosity and wide perivascular spaces

The autosomal dominant progeroid form of cutis laxa is a recently identified multiple congenital anomaly disorder characterized by thin, wrinkled skin, a progeroid appearance, intra-uterine growth retardation, postnatal growth restriction, psychomotor developmental delay, microcephaly, cataract, hypotonia and contractures. De novo heterozygous mutations in ALDH18A1 have been described in this condition. We present neuroimaging abnormalities in three patients. One patient had intracranial arterial and venous tortuosity, widened ventricular and extra-axial cerebrospinal fluid (CSF) spaces, wide perivascular spaces and increased T2 signal intensity in the cerebral white matter over time. The second patient had vascular tortuosity. The third patient had prominent ventricular and extra-axial cerebrospinal fluid (CSF) spaces on CT. We propose an embryological mechanism for the development of intracranial vascular tortuosity and discuss the anatomical basis of wide perivascular spaces in relation to this syndrome. Although we do not know the clinical implications of these cerebral vascular anomalies, we suggest inclusion of neuroimaging in the baseline evaluation of these patients.

Coronary capillary blood flow in a rat model of congestive heart failure

The aim of this study was to explore the role of abnormal coronary microvasculature morphology and hemodynamics in the development of congestive heart failure (CHF). CHF was induced in rats by aortic banding, followed by ischemia-reperfusion and later aortic debanding. Polymerized casts of coronary vasculature were imaged under a scanning electron microscope (SEM). Matrix Laboratory (MATLAB) software was used to calculate capillary structure index (CSI), a measure of structural alignment also called mean vector length (MVL), for 93 SEM images of coronary capillaries (CSI→1 perfect linearity; CSI→0 circular disarray). CSI was incorporated as a constant to represent tortuosity and nonlaminar flow in Poiseuille's equation to estimate the differences in capillary blood flow rate, velocity, and resistance for CHF vs.

CONTROL

The morphology of CHF capillaries is significantly disordered and tortuous compared with control (CSI: 0.35 ± 0.02 for 61 images from 7 CHF rats; 0.58 ± 0.02 for 32 images from 7 control rats; P < 0.01). Estimated capillary resistance in CHF is elevated by 173% relative to control, while blood flow rate and blood velocity are 56 and 43% slower than control. Capillary resistance increased 67% due to the significantly narrower capillary diameter in CHF, while it increased an additional 105% due to tortuosity. The significant structural abnormalities of CHF coronary capillaries may drastically stagnate hemodynamics in myocardium and increase resistance to blood flow. This could play a role in the development of CHF. NEW & NOTEWORTHY In the present study, coronary capillary tortuosity was measured by applying Matrix Laboratory software to scanning electron microscope images of capillaries in a rat model of congestive heart failure. Stagnant blood flow in coronary capillaries may play a role in the development of congestive heart failure. The application of computer modeling to histological and physiological data to characterize the hemodynamics of coronary microcirculation is a new area of study.

Tortuous Microvessels Contribute to Wound Healing via Sprouting Angiogenesis

Supplemental Digital Content is available in the text.

Objective—

Wound healing is accompanied by neoangiogenesis, and new vessels are thought to originate primarily from the microcirculation; however, how these vessels form and resolve during wound healing is poorly understood. Here, we investigated properties of the smallest capillaries during wound healing to determine their spatial organization and the kinetics of formation and resolution.

Approach and Results—

We used intravital imaging and high-resolution microscopy to identify a new type of vessel in wounds, called tortuous microvessels. Longitudinal studies showed that tortuous microvessels increased in frequency after injury, normalized as the wound healed, and were closely associated with the wound site. Tortuous microvessels had aberrant cell shapes, increased permeability, and distinct interactions with circulating microspheres, suggesting altered flow dynamics. Moreover, tortuous microvessels disproportionately contributed to wound angiogenesis by sprouting exuberantly and significantly more frequently than nearby normal capillaries.

Conclusions—

A new type of transient wound vessel, tortuous microvessels, sprout dynamically and disproportionately contribute to wound-healing neoangiogenesis, likely as a result of altered properties downstream of flow disturbances. These new findings suggest entry points for therapeutic intervention.

Increased Coronary Tortuosity Is Associated with Increased Left Ventricular Longitudinal Myocardial Shortening

BACKGROUND

The mechanistic basis for tortuosity of the coronary arteries (TCA) is unclear. The aim of this study was to test the hypothesis that the relative degree of systolic longitudinal shortening of the left ventricle that deforms coaxially oriented coronary arteries is associated with TCA.

METHODS

Adult subjects undergoing coronary angiography and comprehensive echocardiography within 3 months were classified dichotomously as with (n = 32) or without (n = 42) TCA defined on the basis of number and severity of coronary angles. Systolic left ventricular (LV) longitudinal deformation was determined by mitral annular plane systolic excursion (MAPSE) from both B-mode displacement and tissue Doppler time-velocity integral; data were indexed to LV diastolic long-axis length.

RESULTS

There were no differences between groups with respect to age, gender, hypertension, or coronary artery disease. Patients with TCA had significantly (P < .01) lower LV mass index and a shorter total LV diastolic long-axis length (mean, 8.3 ± 1.9 vs 9.1 ± 2.2 cm; P < .01). Despite having a shorter length, those with TCA had greater MAPSE by both methods. MAPSE normalized to diastolic length was significantly greater (P < .01) in those with TCA, which remained the case after excluding subjects with reduced LV ejection fraction. Multiple linear regression found that lateral annular MAPSE had the largest effect size, with a 13-fold increase in likelihood for TCA for every 0.1 of normalized MAPSE.

CONCLUSIONS

TCA is not associated with increased LV mass but rather with smaller hearts that have greater relative longitudinal shortening of the left ventricle. This finding suggests that TCA could represent an adaptive response to longitudinal systolic distortion of coaxially oriented coronary arteries that dynamically produce shear stresses associated with expansive coronary remodeling.

Recipient umbilical artery elongation (redundancy) in twin-twin transfusion syndrome

BACKGROUND

Chronic hypertension in adults causes arterial lengthening in major arteries, but the effects of early fetal hypertension on the twin-twin transfusion syndrome recipient's vascular architecture remains unknown.

OBJECTIVE

We hypothesize that arterial cord redundancy is related to recipient hypertension and subsequent heart failure. Our objectives were to: (1) establish a 3-dimensional color Doppler ultrasound method of measuring umbilical arterial length relative to its corresponding venous segment in the umbilical cord using artery vein angle; (2) compare recipient artery vein angle to gestational age-matched controls; and (3) test the association of artery vein angle with recipient heart failure.

STUDY DESIGN

We compared 3 groups prospectively: twin-twin transfusion syndrome pregnancies undergoing fetoscopic laser surgery (preoperatively) and 2 groups of gestational age-matched controls: uncomplicated monochorionic-diamniotic twin pregnancies and healthy singletons. Using a 3-dimensional color-Doppler volume image of 5 cm of cord near the placental insertion, we traced the umbilical artery and vein producing umbilical artery:vein length, (artery vein index) and measured the artery vein angle between umbilical artery and vein. Correlation of artery vein angle to twin-twin transfusion syndrome stage, maximum vertical pocket, umbilical arterial indices, ductus venosus Doppler, and brain natriuretic peptide were performed. We used pulsed-wave and tissue Doppler to measure tissue Doppler velocities and indexed cardiac output and correlated these with artery vein angle. Comparative statistics, including multivariable linear regression, examined the relationship between umbilical arterial Doppler indices and artery vein angle.

RESULTS

Artery vein angle and artery vein index correlated significantly (R², 0.86; P < .0001), hence, artery vein angle was used for analysis. Mean artery vein angle was 33.1 ± 31.5 degrees in recipients (n = 44), 9.5 ± 6 degrees in monochorionic-diamniotic (n = 11; 22 fetuses), and 8.9 ± 8.3 degrees in singleton controls (n = 16) (P < .001). An artery vein angle ≥26 degrees (>95th percentile for controls) was measured in 52% recipients. Artery vein angle was higher in twin-twin transfusion syndrome stage 3R vs 1 (P = .001). Artery vein angle increased with increasing umbilical arterial pulsatility index (P < .001), and decreased with increasing resistance index (P = .02) after adjusting for gestational age. Interrater agreements to categorize abnormal artery vein angle values was 95% (P < .001). Abnormal ductus venosus Doppler and elevated recipient amniotic fluid N-terminal pro-brain natriuretic peptide/protein levels correlated significantly with artery vein angle. Abnormal artery vein angles were associated with decreased indexed cardiac output, lower tissue Doppler velocities, higher right-sided Tei indices, and severe tricuspid regurgitation.

CONCLUSION

Umbilical arterial lengthening occurs in 52% of recipients and is associated with abnormal Doppler flows, low systolic tissue Doppler velocities, reduced cardiac output, and elevated markers of cardiac failure. This may reflect chronicity and severity of hypertension in the recipient fetus. Further research is needed to explore the mechanisms of elongation and long-term implications.

Coronary Tortuosity: A Clue to the Diagnosis of Fibromuscular Dysplasia?

BACKGROUND

Fibromuscular dysplasia (FMD) is a systemic, nonatherosclerotic, noninflammatory vasculopathy that is often overlooked by clinicians. Clinical clues could help in selecting patients for further evaluation for the presence of FMD. Recently, it was observed that tortuosity of the coronary arteries is often present in patients with FMD-related abnormalities of the coronary artery. Therefore, we wondered if the presence of coronary tortuosity might provide a clinical clue to the diagnosis of extracoronary FMD.

CASES

We describe 5 cases of FMD in whom diagnostic studies for FMD were initiated because of the presence of coronary tortuosity. FMD was found in all 5 patients in the renal and/or cervical arteries.

CONCLUSIONS

Our 5 cases suggest that exertional chest pain in the presence of coronary tortuosity may be helpful in selecting patients for further evaluation for the presence of FMD. Further research should focus on the prevalence of FMD among patients with coronary tortuosity and whether the presence of additional clinical clues (such as the presence of hypertension at young age or pulsatile tinnitus) next to coronary tortuosity can predict the risk for FMD in individual patients.

Use of Simple Neck Extension to Improve Guiding Catheter Accessibility in Tortuous Cervical Internal Carotid Artery for Endovascular Embolization of Intracranial Aneurysm: A Technical Note

BACKGROUND

In endovascular embolization of intracranial aneurysms, a tortuous cervical internal carotid artery can limit guiding catheter access to a sufficiently high position. Although intermediate distal access catheters can go beyond the tortuous segment of internal carotid arteries, they may increase the risk of procedure-related complications, require significantly complex technical procedures, and limit the use of adjunctive techniques. Using simple neck extension alone, we successfully improved guiding catheter access in 2 patients.

METHODS

Through a provocative test, we confirmed suitability of manual neck extension in 2 patients with severe posterior curvature of a tortuous internal carotid artery. Intraoperatively, we manually extended the neck and stretched the curvatures. We guided a 6F guiding catheter superiorly and performed coil embolization with an occlusion balloon catheter in 1 case and with the balloon-assisted neck remodeling technique in 1 case.

RESULTS

Coil embolization was completed without any adverse events in both cases.

CONCLUSIONS

The simple neck extension technique successfully improved accessibility of the guiding catheter. As the need for safe and highly skilled intervention increases, our technique may be useful because it can reduce procedure-related complications and allow balloon-assisted techniques.

Vessel shape alterations of the vertebrobasilar arteries in Mucopolysaccharidosis type IVa (Morquio A) patients

PURPOSE

Main symptom of mucopolysaccharidosis type IVa (MPS IVa) is progressive systemic skeletal dysplasia. This is routinely monitored by cerebral and spinal MRI. The vascular system is generally not in the primary focus of interest. In our population of MPS IVa patients we observed vessel shape alterations of the vertebrobasilar arteries, which has not been described before.

MATERIAL AND METHODS

MRI-datasets of 26 patients with MPS IVa acquired between 2008 and 2015 were eligible for retrospective analysis of the vertebrobasilar arteries. The vessel length and angle of the basilar artery (BA) and both vertebral arteries (VA) were analyzed. A deflection angle between 90° and 130° in the vessel course was defined as tortuosity, less than 90° as kinking. The results were compared to a matched control group of 23 patients not suffering from MPS.

RESULTS

The deflection angle [°] of the VA and BA was significantly decreased in the majority (85%) of MPS IVa patients compared to the control group: BA 132±24 vs. 177±6, BA/VA transition 113±21 vs. 152±13, right VA 108±23 vs. 156±13, left VA 110± 22 vs. 157±14 (all p<0.005). Likewise, vessels of MPS IVa patients were significantly longer compared to the control group: BA 27±4 vs. 21±2, right VA 20±6 vs. 10±1, left VA 18±5 vs. 11±2 (all p<0.005).

CONCLUSION

MPS IVa is associated with significantly increased tortuosity of vertebrobasilar arteries. Therefore the vascular system of MPS IVa patients should be monitored on routinely basis, as vessel shape alterations had been associated with dissections, leading to a higher risk of cerebrovascular events.

Transcranial doppler sonography is not a valid diagnostic tool for detection of basilar artery stenosis or in-stent restenosis: a retrospective diagnostic study

Background

There are contradictory reports concerning the validity of transcranial sonography (TCD and TCCS) for examinations of the basilar artery. Here we investigated sensitivity and specificity of transcranial sonography for the detection of basilar artery stenosis and in-stent-restenosis compared to cerebral angiography.

Methods

We analyzed data of 104 examinations of the basilar artery. The association between sonographic peak systolic velocity (PSV) and degree of stenosis obtained by cerebral angiography was evaluated applying Spearman’s correlation coefficient. Receiver Operating Characteristics (ROC) curves and areas under the curve (AUC) were calculated for the detection of a ≥50% stenosis defined by angiography. Optimal cut-off was derived using the Youden-index.

Results

A weak but statistically significant correlation between PSV and the degree of stenosis was found (n=104, rho=0.35, p<0.001). ROC analysis for a detection of ≥50% stenosis showed an AUC of 0.70, a sensitivity of 74.0% and a specificity of 65.0% at the optimal cut off of 124 cm/s. Results were consistent when analyzing examinations done in stented and unstented arteries separately (TCD VS DSA/CTA in unstented artery: AUC=0.66, sensitivity 61.0%, specificity 65.0%, TCD/TCCS VS DSA in stented artery: AUC=0.63, sensitivity 71.0%, specificity 82.0%). Comparing TCCS measurements exclusively to angiography, ROC analysis showed an AUC of 1.00 for the detection of an in-stent-restenosis ≥50% with a sensitivity and specificity of 100% when a PSV of 132 cm/s was used as a cut off value.

Conclusion

Validity of TCD in the assessment of basilar artery stenosis or in-stent restenosis is poor. First results for TCCS are promising, but due to the small samplesize further studies with larger samples sizes are warranted.

Twist buckling of veins under torsional loading

Veins are often subjected to torsion and twisted veins can hinder and disrupt normal blood flow but their mechanical behavior under torsion is poorly understood. The objective of this study was to investigate the twist deformation and buckling behavior of veins under torsion. Twist buckling tests were performed on porcine internal jugular veins (IJVs) and human great saphenous veins (GSVs) at various axial stretch ratio and lumen pressure conditions to determine their critical buckling torques and critical buckling twist angles. The mechanical behavior under torsion was characterized using a two-fiber strain energy density function and the buckling behavior was then simulated using finite element analysis. Our results demonstrated that twist buckling occurred in all veins under excessive torque characterized by a sudden kink formation. The critical buckling torque increased significantly with increasing lumen pressure for both porcine IJV and human GSV. But lumen pressure and axial stretch had little effect on the critical twist angle. The human GSVs are stiffer than the porcine IJVs. Finite element simulations captured the buckling behavior for individual veins under simultaneous extension, inflation, and torsion with strong correlation between predicted critical buckling torques and experimental data (R²=0.96). We conclude that veins can buckle under torsion loading and the lumen pressure significantly affects the critical buckling torque. These results improve our understanding of vein twist behavior and help identify key factors associated in the formation of twisted veins.

Relationship between coronary tortuosity and plateletcrit coronary tortuosity and plateletcrit

Background

Coronary tortuosity (CorT) is a common angiographic finding and may be associated with myocardial ischaemia, even without coronary artery disease. Platelets play a crucial role in inflammatory and thrombotic processes and the physiopathology of cardiovascular disease. Larger platelets are more active enzymatically and have higher thrombotic ability compared to smaller platelets. Plateletcrit (PCT) provides complete information on total platelet mass. We aimed to evaluate the relationship between CorT and PCT in patients with chronic stable angina.

Methods

The medical records of consecutive patients who underwent coronary angiography from January 2013 to January 2016 were retrospectively reviewed for CorT. CorT and clinical, echocardiographic, haematological and biochemical parameters were evaluated. Taking into consideration the inclusion criteria, 106 patients with CorT and 108 with normal coronary angiographies (control group) were included in the study. CorT was defined as three fixed bends during both systole and diastole, with each bend ≥ 45°.

Results

The median PCT, mean platelet volume (MPV), platelet:large-cell ratio (P-LCR), neutrophil:lymphocyte ratio (NLR) and platelet:lymphocyte ratio (PLR) of the CorT group were significantly higher than those of the control group (0.26 ± 0.02 vs 0.2 ± 0.03%, p < 0.001; 10.6 ± 0.14 vs 9.6 ± 0.65 fl, p < 0.001; 29.3 ± 6.7 vs 23.4 ± 5.1, p < 0.001; 2.3 ± 1 vs 1.47 ± 0.48, p < 0.001; 1.28 ± 0.5 vs 0.82 ± 0.23, p < 0.001, respectively). The incidence of diabetes mellitus, hypertension and female gender were significantly higher in the CorT group (18.9 vs 1.9%, p < 0.001, 90.6 vs 50%, p < 0.001, 70.8 vs 44.4%, p < 0.001, respectively). Multivariate logistic regression analysis revealed age, hypertension, diabetes mellitus and plateletcrit were independently associated with CorT.

Conclusion

CorT was associated with increased PCT, MPV, P-LCR, NLR and PLR, even in the absence of coronary artery disease. Age, hypertension, diabetes mellitus and plateletcrit were independently associated with CorT.

BOLD neurovascular coupling does not change significantly with normal aging

Studies of cognitive function that compare the blood oxygenation level dependent (BOLD) signal across age groups often require the assumption that neurovascular coupling does not change with age. Tests of this assumption have produced mixed results regarding the strength of the coupling and its relative time course. Using deconvolution, we found that age does not have a significant effect on the time course of the hemodynamic impulse response function or on the slope of the BOLD versus stimulus duration relationship. These results suggest that in cognitive studies of healthy aging, group differences in BOLD activation are likely due to age-related changes in cognitive-neural interactions and information processing rather than to impairments in neurovascular coupling. Hum Brain Mapp 38:3538-3551, 2017. © 2017 Wiley Periodicals, Inc.

Vertebrobasilar system computed tomographic angiography in central vertigo

The incidence of vertigo in the population is 20% to 30% and one-fourth of the cases are related to central causes. The aim of this study was to evaluate computed tomography angiography (CTA) findings of the vertebrobasilar system in central vertigo without stroke.CTA and magnetic resonance images of patients with vertigo were retrospectively evaluated. One hundred twenty-nine patients suspected of having central vertigo according to history, physical examination, and otological and neurological tests without signs of infarction on diffusion-weighted magnetic resonance imaging were included in the study. The control group included 120 patients with similar vascular disease risk factors but without vertigo. Vertebral and basilar artery diameters, hypoplasias, exit-site variations of vertebral artery, vertebrobasilar tortuosity, and stenosis of ≥50% detected on CTA were recorded for all patients. Independent-samples t test was used in variables with normal distribution, and Mann-Whitney U test in non-normal distribution. The difference of categorical variable distribution according to groups was analyzed with χ and/or Fisher exact test.Vertebral artery hypoplasia and ≥50% stenosis were seen more often in the vertigo group (P = 0.000, <0.001). Overall 78 (60.5%) vertigo patients had ≥50% stenosis, 54 (69.2%) had stenosis at V1 segment, 9 (11.5%) at V2 segment, 2 (2.5%) at V3 segment, and 13 (16.6%) at V4 segment. Both vertigo and control groups had similar basilar artery hypoplasia and ≥50% stenosis rates (P = 0.800, >0.05).CTA may be helpful to clarify the association between abnormal CTA findings of vertebral arteries and central vertigo.This article reveals the opportunity to diagnose posterior circulation abnormalities causing central vertigo with a feasible method such as CTA.

Retinal microvascular plasticity in a premature neonate

Dilation and abnormal tortuosity of retinal vessels are the hallmarks of severe retinopathy of prematurity (ROP) in premature infants. The stages of ROP are defined by vessel appearance at the interface between the vascular and avascular retinal areas. Deregulated signaling pathways involving hypoxia-inducible factors such as vascular endothelial growth factor (VEGF) are involved in the pathogenesis of ROP. VEGF-antagonists are increasingly being used as 'off-label medication' to treat this condition, with some success. We present Baby SM (female), who was born prematurely at 24 weeks gestation in a tertiary neonatal intensive care unit, and with a birth weight of 640 g. On screening at 35 weeks postmenstrual age (PMA), she was noted to have ROP, which became severe by 37 weeks PMA. She received one dose of intravitreal VEGF antagonist (Bevacizumab), resulting in a decrease in vessel tortuosity and dilation. However, repeat imaging at 4 weeks showed a re-emergence of vessel tortuosity. We believe the observed changes demonstrate an inherent retinal microvascular plasticity in premature neonates. With improved survival of extremely premature neonates and the availability of retinal imaging technology, we are now able to observe this plasticity.

Numerical Simulation of Thrombotic Occlusion in Tortuous Arterioles

Tortuous microvessels alter blood flow and stimulate thrombosis but the physical mechanisms are poorly understood. Both tortuous microvessels and abnormally large platelets are seen in diabetic patients. Thus, the objective of this study was to determine the physical effects of arteriole tortuosity and platelet size on the microscale processes of thrombotic occlusion in microvessels. A new lattice-Boltzmann method-based discrete element model was developed to simulate the fluid flow field with fluid-platelet coupling, platelet interactions, thrombus formation, and thrombotic occlusion in tortuous arterioles. Our results show that vessel tortuosity creates high shear stress zones that activate platelets and stimulate thrombus formation. The growth rate depends on the level of tortuosity and the pressure and flow boundary conditions. Once thrombi began to form, platelet collisions with thrombi and subsequent activations were more important than tortuosity level. Thrombus growth narrowed the channel and reduced the flow rate. Larger platelet size leads to quicker decrease of flow rate due to larger thrombi that occluded the arteriole. This study elucidated the important roles that tortuosity and platelet size play in thrombus formation and occlusion in arterioles.

Tortuous Carotid Artery Extended to Neck Level IIb Mimicking the Metastatic Mass

Specifically in neck level IIb, the expected normal anatomy does not contain any vital structures and consequently it might direct a surgeon to perform rapid surgical dissection of tissues. Therefore aberrant anatomy of the vessels in the patients may be overlooked during neck dissection. Unexpected and potentially devastating injuries can be avoided by respecting the possible aberrant anatomy in any level of the neck. In this case report, a 74-year-old man was presented with laryngeal carcinoma who was treated with laryngectomy and bilateral neck dissection. During the left side neck dissection, tortuous internal carotid artery imitating a metastatic mass was unexpectedly encountered in level IIb. As in this case, surgeons should keep in mind possible aberrant anatomy during the neck dissection and perform surgery staying in surgical principles to be safe for an unforeseen and potential dangerous injuries.

Delineation of Ehlers-Danlos syndrome phenotype due to the c.934C>T, p.(Arg312Cys) mutation in COL1A1: Report on a three-generation family without cardiovascular events, and literature review

Classical Ehlers-Danlos syndrome (cEDS) is a rare connective tissue disorder primarily characterized by hyperextensible skin, defective wound healing, abnormal scars, easy bruising, and generalized joint hypermobility; arterial dissections are rarely observed. Mutations in COL5A1 and COL5A2 encoding type V collagen account for more than 90% of the patients so far characterized. In addition, cEDS phenotype was reported in a small number of patients carrying the c.934C>T mutation in COL1A1 that results in an uncommon substitution of a non-glycine residue in one Gly-Xaa-Yaa repeat of the pro-α1(I)-chain p.(Arg312Cys), which leads to disturbed collagen fibrillogenesis due to delayed removal of the type I procollagen N-propeptide. This specific mutation has been associated with propensity to arterial rupture in early adulthood; indeed, in literature the individuals harboring this mutation are also referred to as "(classic) vascular-like" EDS patients. Herein, we describe a three-generation cEDS family with six adults carrying the p.(Arg312Cys) substitution, which show a variable and prevalent cutaneous involvement without any major vascular event. These data, together with those available in literature, suggest that vascular events are not a diagnostic handle to differentiate patients with the p.(Arg312Cys) COL1A1 mutation from those with COL5A1 and COL5A2 defects, and highlight that during the diagnostic process the presence of at least the p.(Arg312Cys) substitution in COL1A1 should be investigated in cEDS patients without type V collagen mutations. Nevertheless, for these patients, as well as for those affected with cEDS, a periodical vascular surveillance should be carried out together with cardiovascular risk factors monitoring. © 2016 Wiley Periodicals, Inc.

Vascular Tortuosity May Be Associated With Cervical Artery Dissection

BACKGROUND AND PURPOSE

Dissection is an increasingly recognized cause of ischemic stroke, which occurs spontaneously or after trauma, in relatively young patients. We hypothesized that there might be a predisposing factor weakening the vascular wall and that arterial tortuosity might be higher in patients with dissection.

METHODS

We consecutively enrolled cervical artery dissection (CerAD) patients who had undergone magnetic resonance angiography. Age- and sex-matched healthy subjects who underwent magnetic resonance angiography in a routine health examination were used as controls. The tortuosity was measured semiautomatically from the carotid artery and vertebral artery (VA) arteries. Tortuosity index was defined as: [(arc/chord)-1×100] in each arteries. Independent risk factors associated with CerAD were investigated using multivariable analysis. Subgroup analysis according to the dissected artery was performed.

RESULTS

There were no differences in vascular risk factors between the 75 CerAD patients and the 75 controls. The tortuosity indexes of the contralesional VA (16.3±6.8 versus 12.1±4.5, respectively; P<0.001) and carotid artery (8.8±4.0 versus 7.3±2.9, respectively; P=0.01) were higher in patients with CerAD compared with those of control subjects. VA tortuosity (odds ratio, 1.175; P=0.001) was independently associated with the presence of CerAD. In subgroup analysis, VA tortuosity was significantly higher in 57 patients with VA dissection than in controls (P<0.001), and carotid artery tortuosity was marginally higher in 18 patients with carotid artery dissection (P=0.05).

CONCLUSIONS

CerAD is associated with tortuous cervical arteries, which may implicate weakened cervical vascular structure in these patients.

Mechanical behavior and wall remodeling of blood vessels under axial twist

Blood vessels are often subjected to axial torsion (or twist) due to body movement or surgery. However, there are few studies on blood vessel under twist. This review first summarizes the clinical observation on the twist of blood vessels and then presents what we know about the mechanical behaviors of blood vessel under twist, including the constitutive models. The state of art researches on the remodeling of blood vessels under twist via ex vivo organ culture, in vivo animal experiments, and mathematical model simulations are further discussed. It is our hope that this review will draw attention for further in-depth studies on the behavior and remodeling of blood vessels under twist.

Pulmonary vascular morphology as an imaging biomarker in chronic thromboembolic pulmonary hypertension

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) have morphologic changes to the pulmonary vasculature. These include pruning of the distal vessels, dilation of the proximal vessels, and increased vascular tortuosity. Advances in image processing and computer vision enable objective detection and quantification of these processes in clinically acquired computed tomographic (CT) scans. Three-dimensional reconstructions of the pulmonary vasculature were created from the CT angiograms of 18 patients with CTEPH diagnosed using imaging and hemodynamics as well as 15 control patients referred to our Dyspnea Clinic and found to have no evidence of pulmonary vascular disease. Compared to controls, CTEPH patients exhibited greater pruning of the distal vasculature (median density of small-vessel volume: 2.7 [interquartile range (IQR): 2.5-3.0] vs. 3.2 [3.0-3.8]; P = 0.008), greater dilation of proximal arteries (median fraction of blood in large arteries: 0.35 [IQR: 0.30-0.41] vs. 0.23 [0.21-0.31]; P = 0.0005), and increased tortuosity in the pulmonary arterial tree (median: 4.92% [IQR: 4.85%-5.21%] vs. 4.63% [4.39%-4.92%]; P = 0.004). CTEPH was not associated with dilation of proximal veins or increased tortuosity in the venous system. Distal pruning of the vasculature was correlated with the cardiac index (R = 0.51, P = 0.04). Quantitative models derived from CT scans can be used to measure changes in vascular morphology previously described subjectively in CTEPH. These measurements are also correlated with invasive metrics of pulmonary hemodynamics, suggesting that they may be used to assess disease severity. Further work in a larger cohort may enable the use of such measures as a biomarker for diagnostic, phenotyping, and prognostic purposes.