Preference for ethanol in the rhesus monkey following chronic infusion of ethanol into the cerebral ventricles. Physiol Behav. 1972;8:431-435. [PMID: 4624847 DOI: 10.1097/hco.0000000000000218]

Tortuosity in non-atherosclerotic vascular diseases is associated with age, arterial aneurysms, and hypertension

BACKGROUND

Increased arterial tortuosity has been associated with various cardiovascular complications. However, the extent and role of arterial tortuosity in non-atherosclerotic vascular diseases remain to be fully elucidated. This study aimed to assess arterial tortuosity index (ATI) in patients with non-atherosclerotic vascular diseases and the associated factors.

METHODS

This is a retrospective analysis of patients with non-atherosclerotic vascular diseases referred to the Malformation and Rare Vascular Disease Center at the University Hospital in Lausanne (Switzerland). Computed tomography angiography (CTA) images performed between October 2010 and April 2022 were retrieved and the aortic tortuosity index (ATI) was calculated. Patients were classified based on diagnosis into the following groups: arterial dissection & aneurysm, arteritis & autoimmune disease, hereditary connective tissue diseases, and fibromuscular dysplasia (FMD). Univariate and multivariate logistic regression analysis was used to determine potentially relevant predictors of aortic tortuosity.

RESULTS

The mean age upon computed tomography angiography (CTA) was 46.8 (standard deviation [SD] 14.6) years and 59.1% of the patients were female. Mean ATI was higher in patients over 60 years old (1.27), in those with arterial aneurysms (mean: 1.11), and in those diagnosed with hypertension (mean: 1.13). When only patients over 60 years old were considered, those diagnosed with connective tissue diseases had the highest ATI. At multivariate regression analysis, increasing age (p < 0.05), presence of arterial aneurysms (p < 0.05), and hypertension (p < 0.05) were independently associated with ATI.

CONCLUSIONS

The ATI may be a promising tool in diagnostic evaluation, cardiovascular risk stratification, medical or surgical management, and prognostic assessment in several non-atherosclerotic vascular conditions. Further studies with longitudinal design and larger cohorts are needed to validate the role of ATI in the full spectrum of vascular diseases.

Arterial tortuosity in pediatric Loeys-Dietz syndrome patients

Loeys-Dietz syndrome (LDS) is an autosomal connective tissue disorder commonly presenting with hypertelorism, bifid uvula, aortic aneurysms, and arterial tortuosity. The aim of the present study was to investigate differences in tortuosity index (TI) between genotypes of LDS, possible progression over time and its use as an adjunctive prognostic tool alongside aortic dimensions to aid timely surgical planning in pediatric patients. A retrospective observational study of pediatric LDS patients referred to our center (November 2012-February 2021) was conducted. Using magnetic resonance angiography (MRA) with 3D maximum intensity projection volume-rendered angiogram, arterial TI was measured. Twenty three patients had genetically confirmed LDS with at least one head and neck MRA and 19 had no less than one follow-up MRA available. All patients presented arterial tortuosity. Patients with TGFBR2 variants had greater values of TI compared to patients with TGFB2 variants (p = 0.041). For patients who did not undergo surgery (n = 18), z-scores at the level of the sinus of Valsalva showed a significant correlation with vertebral TI (rs  = 0.547). There was one death during follow-up. This study demonstrates that patients with LDS and TGFBR2 variants have greater values of TI than patients with TGFB2 variants and that greatest values of TI are associated with increased aortic root z-scores. Furthermore, as TI decreases over time, less frequent neuroimaging follow-up can be considered. Nevertheless, additional studies are needed to better define more accurate risk stratification and long-term surveillance in these patients.

Echogenomics: Echocardiography in Heritable Aortopathies

PURPOSE OF REVIEW

The aim of this article is to review the current echocardiographic considerations in the diagnosis and monitoring of patients with inherited aortopathies.

RECENT FINDINGS

Aortic dilation is a key feature in heritable aortopathies, and dissection is a leading cause of morbidity and mortality. New genetic and histopathologic findings are helpful in better understanding these conditions. Non-invasive imaging modalities, including echocardiogram, computerized tomography, and magnetic resonance imaging, are essential in monitoring these patients, as well as providing new prognostic factors of arterial stiffness that may help with risk stratification in the future. Diagnosis of heritable aortopathies should be considered with identification of aortic root dilation, particularly in children and young adults, or when there is a family history of aortic disease. Recent adult consensus guidelines highlight the importance of underlying genotype and phenotypic features when considering prophylactic surgical intervention. There are currently no consensus pediatric guidelines.

Cervical artery tortuosity-a reliable semi-automated magnetic resonance-based method

Background

Assessments of subclinical connective tissue disorders depend on complex approaches, emphasizing the need for more accessible methods applicable to clinical routine. Therefore, we aimed to establish a reliable approach assessing cervical vessel tortuosity, which is known to be associated with such disorders.

Methods

Magnetic resonance angiography (MRA) images of ReSect study participants [single-center prospective cohort of spontaneous cervical artery dissection (sCeAD) patients] were used. Each patient underwent the same magnetic resonance imaging (MRI) protocol. The segmentation procedure was done using MATrix LABoratory 9.4 [up-sampling of raw MRA images, distance metric (DM) calculation], ITK-SNAP [region of interest (ROI) determination, vessel segmentation] and Vascular Modelling ToolKit (centerline determination). To assess inter-user variability and validity, we (I) had two blinded independent users segment all arteries and we (II) compared the results of our method to visual appraisal of vessel tortuosity done by two blinded expert neuro-radiologists.

Results

A total of 526 extracranial cervical arteries were available for analysis. The inter-user variability of our method users was below 0.5% throughout. Overall, our method outperformed the visual tortuosity appraisal, as the visual grading underestimated the DM in 38.8% subjects when tasked to assess overall cervical artery tortuosity (both vertebral and internal carotid arteries) and in 16.6% and 33.3% respectively if tasked to grade anterior or posterior circulation separately.

Conclusions

We present a reliable method to assess cervical artery tortuosity derived from MRA images applicable in clinical routine and future research investigating the potential correlation of sCeAD and connective tissue disorder.

Vertebral Tortuosity Is Associated With Increased Rate of Cardiovascular Events in Vascular Ehlers-Danlos Syndrome

Background Arterial tortuosity is associated with adverse events in Marfan and Loeys-Dietz syndromes but remains understudied in Vascular Ehlers-Danlos syndrome. Methods and Results Subjects with a pathogenic COL3A1 variant diagnosed at age <50 years were included from 2 institutions and the GenTAC Registry (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions). Height-adjusted vertebral artery tortuosity index (VTI-h) using magnetic resonance or computed tomography angiography was calculated. Associations between VTI-h and outcomes of (1) cardiovascular events (arterial dissection/rupture, aneurysm requiring intervention, stroke), or (2) hollow organ collapse/rupture at age <50 years were evaluated using receiver operator curve analysis (using outcome by age 30 years) and mixed-effects Poisson regression for incidence rate ratios. Of 65 subjects (54% male), median VTI-h was 12 (interquartile range, 8-16). Variants were missense in 46%, splice site in 31%, and null/gene deletion in 14%. Thirty-two subjects (49%) had 59 events, including 28 dissections, 5 arterial ruptures, 4 aneurysms requiring intervention, 4 strokes, 11 hollow organ ruptures, and 7 pneumothoraces. Receiver operator curve analysis suggested optimal discrimination at VTI-h ≥15.5 for cardiovascular events (sensitivity 70%, specificity 76%) and no association with noncardiovascular events (area under the curve, 0.49 [95% CI, 0.22-0.78]). By multivariable analysis, older age was associated with increased cardiovascular event rate while VTI-h ≥15.5 was not (incidence rate ratios, 1.79 [95% CI, 0.76-4.24], P=0.185). However, VTI-h ≥15.5 was associated with events among those with high-risk variants <40 years (incidence rate ratios, 4.14 [95% CI, 1.13-15.10], P=0.032), suggesting effect modification by genotype and age. Conclusions Increased arterial tortuosity is associated with a higher incidence rate of cardiovascular events in Vascular Ehlers-Danlos syndrome. Vertebral tortuosity index may be a useful biomarker for prognosis when evaluated in conjunction with genotype and age.

Arterial Tortuosity Syndrome: Unraveling a Rare Vascular Disorder

Arterial tortuosity syndrome (ATS) is a rare genetic disorder characterized by abnormal twists and turns of arteries, leading to cardiovascular complications. This syndrome, first reported around 55 years ago, is inherited in an autosomal recessive manner and affects both genders. ATS manifests primarily in childhood, with arterial abnormalities disrupting blood circulation, increasing shear stress, and causing complications, such as atherosclerosis and strokes. This article reviews the genetics, etiology, pathophysiology, clinical presentation, diagnosis, associated conditions, management, and challenges of ATS. The syndrome's genetic cause is linked to mutations in the SLC2A10 gene, affecting collagen and elastin synthesis. Arterial tortuosity, a complex phenomenon, arises from factors such as vessel elongation, anatomic fixation, and vessel diameter. ATS is one of many conditions associated with arterial tortuosity, including Marfan syndrome and Loeys-Dietz syndrome. Recent studies highlight arterial tortuosity's potential as a prognostic indicator for adverse cardiovascular events. Management requires a multidisciplinary approach, and surveillance and prevention play key roles. Despite challenges, advancements in understanding ATS offer hope for targeted therapies and improved patient care.

The effects of axial twisting and material non-symmetry on arterial bent buckling

Artery buckling occurs due to hypertensive lumen pressure or reduced axial tension and other pathological conditions. Since arteries in vivo often experience axial twisting and the collagen fiber alignment in the arterial wall may become nonsymmetric, it is imperative to know how axial twisting and nonsymmetric collagen alignment would affect the buckling behavior of arteries. To this end, the objective of this study was to determine the effect of axial twisting and nonsymmetric collagen fiber distribution on the critical pressure of arterial bent buckling. The buckling model analysis was generalized to incorporate an axial twist angle and nonsymmetric fiber alignment. The effect of axial twisting on the critical pressure was simulated and experimentally tested in a group of porcine carotid arteries. Our results showed that axial twisting tends to reduce the critical pressure depending on the axial stretch ratio and twist angle. In addition, nonsymmetric fiber alignment reduces the critical pressure. Experimental results confirmed that a twist angle of 90° reduces the critical pressure significantly (p < 0.05). It was concluded that axial twisting and non-axisymmetric collagen fibers distribution could make arteries prone to bent buckling. These results enrich our understanding of artery buckling and vessel tortuosity. The model analysis and results could also be applicable to other fiber reinforced tubes under lumen pressure and axial twisting.

The Vertebral Artery: A Systematic Review and a Meta-Analysis of the Current Literature

(1) Background. The anatomical variations of the vertebral arteries (VAs) have a significant impact both in neurosurgery and forensic pathology. The purpose of this study was to evaluate the variational anatomy of the vertebral artery. We evaluated anatomical aspects regarding the V1 and V2 segments of the VA: origin, course, tortuosity, hypoplasia, and dominance, and established the prevalence of each variation. (2) Methods. We conducted a systematic search in PubMed and Google Scholar databases, up to December 2022. Sixty-two studies, comprising 32,153 vessels, were included in the current meta-analysis. We used a random-effects model with a DerSimonian-Laird estimator. The confidence intervals were set at 95%. The heterogeneity between studies was assessed using I². The funnel plot and Egger's regression test for plot asymmetry were used for the evaluation of publication bias. Statistical significance was considered at p < 0.05. (3) Results. The most common site for the origin of both VAs was the subclavian artery. The aortic arch origin of the left VA had a prevalence of 4.81%. Other origins of the right VAs were noted: aortic arch (0.1%), right common carotid artery (0.1%), and brachiocephalic trunk (0.5%). Ninety-two percent of the VAs entered the transverse foramen (TF) of the C6 vertebra, followed by C5, C7, C4, and least frequently, C3 (0.1%). Roughly one out of four (25.9%) VAs presented a sort of tortuosity, the transversal one representing the most common variant. Hypoplasia occurred in 7.94% of the vessels. Left VA dominance (36.1%) is more common, compared to right VA dominance (25.3%). (4) Conclusions. The anatomy of the VA is highly irregular, and eventual intraoperative complications may be life-threatening. The prevalence of VA origin from the subclavian artery is 94.1%, 92.0% of the VAs entered the TF at C6, 26.6% were tortuous, and 7.94% were hypoplastic.

Cerebral Arteriopathies of Childhood - Current Approaches

Up to more than half of previously healthy children presenting with their first arterial ischemic stroke have a cerebral arteriopathy. Cerebral arteriopathies during childhood can be congenital, reflecting abnormal vessel development, or acquired when caused by disruption of vascular homeostasis. Distinguishing different types of cerebral arteriopathies in children can be challenging but of great clinical value as they may dictate different disease and treatment courses, and clinical and radiologic outcomes. Furthermore, children with stroke due to a specific arteriopathy exhibit distinctive features when compared to those with stroke due to other causes or a different type of arteriopathy. These features become crucial in the management of pediatric stroke by choosing appropriate diagnostic and treatment strategies. The objective of this article is to provide the reader with a comprehensive up-to-date review of the classification, symptoms, diagnosis, treatment, and outcome of cerebral arteriopathies in children.

Experimental and Mouse-Specific Computational Models of the Fbln4SMKO Mouse to Identify Potential Biomarkers for Ascending Thoracic Aortic Aneurysm

PURPOSE

To use computational methods to explore geometric, mechanical, and fluidic biomarkers that could correlate with mouse lifespan in the Fbln4SMKO mouse. Mouse lifespan was used as a surrogate for risk of a severe cardiovascular event in cases of ascending thoracic aortic aneurysm.

METHODS

Image-based, mouse-specific fluid-structure-interaction models were developed for Fbln4SMKO mice (n = 10) at ages two and six months. The results of the simulations were used to quantify potential biofluidic biomarkers, complementing the geometrical biomarkers obtained directly from the images.

RESULTS

Comparing the different geometrical and biofluidic biomarkers to the mouse lifespan, it was found that mean oscillatory shear index (OSImin) and minimum time-averaged wall shear stress (TAWSSmin) at six months showed the largest correlation with lifespan (r2 = 0.70, 0.56), with both correlations being positive (i.e., mice with high OSImean and high TAWSSmin tended to live longer). When change between two and six months was considered, the change in TAWSSmin showed a much stronger correlation than OSImean (r2 = 0.75 vs. 0.24), and the correlation was negative (i.e., mice with increasing TAWSSmin over this period tended to live less long).

CONCLUSION

The results highlight potential biomarkers of ATAA outcomes that can be obtained through noninvasive imaging and computational simulations, and they illustrate the potential synergy between small-animal and computational models.

Constrained Mixture Models of Soft Tissue Growth and Remodeling - Twenty Years After

Soft biological tissues compromise diverse cell types and extracellular matrix constituents, each of which can possess individual natural configurations, material properties, and rates of turnover. For this reason, mixture-based models of growth (changes in mass) and remodeling (change in microstructure) are well-suited for studying tissue adaptations, disease progression, and responses to injury or clinical intervention. Such approaches also can be used to design improved tissue engineered constructs to repair, replace, or regenerate tissues. Focusing on blood vessels as archetypes of soft tissues, this paper reviews a constrained mixture theory introduced twenty years ago and explores its usage since by contrasting simulations of diverse vascular conditions. The discussion is framed within the concept of mechanical homeostasis, with consideration of solid-fluid interactions, inflammation, and cell signaling highlighting both past accomplishments and future opportunities as we seek to understand better the evolving composition, geometry, and material behaviors of soft tissues under complex conditions.

Correlations between aortic tortuosity, diameter and presence of acute type A aortic dissection

BACKGROUND

Currently, only patients with ascending aorta diameter exceeding 55mm will undergo prophylactic surgery. However, diameter alone is insufficient for precise risk stratification. An International Registry of Acute Aortic Dissections study showed that nearly 60% of patients with type A aortic dissection had a diameter<55mm. This study aims to compare the tortuosity of the ascending aorta between ATAAD patients and healthy controls and evaluate correlations between aortic tortuosity/diameter and presence of ATAAD.

METHODS

A total of 75 cases in the ATAAD group and 83 cases in the Control group were enrolled. Tortuosity was calculated as the ratio of the total curve length (Lc) of the centerline to the linear distance (d) between its two endpoints, as assessed by an electronic caliper. The measurements were made on all patients by just one cardiovascular radiologist using 3-dimensional computerized tomographic imaging. ROC analysis was used to reckon the best cut-off level that prognosis occurrence of ATAAD. Correlation analysis was used to evaluate the correlation between ATAAD and tortuosity.Logistic regression was used to evaluate the relation between ATAAD and tortuosity. The tortuosity of ascending aorta was compared with a healthy control group using propensity score.

RESULTS

According to the ROC analysis, the best cut-off level that prognosis occurrence of ATAAD was 0.135. In addition, the occurrence of ATAAD showed a strong correlation with maximum diameter of the ascending aorta (r 0.587, p < 0.001), and moderate correlation with ascending aortic Tortuosity (r 0.425, p<0.001). 96 patients were matched based on propensity scores (ATAAD n=48, controls n=48). The ascending aorta was more tortuous and more dilated in ATAAD patients compared with healthy controls (0.15±0.06 vs. 0.11±0.05, p<0.001, 37.96mm±7.31 vs. 31.67mm±2.78, p<0.001, respectively).

CONCLUSIONS

Our study found that the occurrence of ATAAD showed a strong correlation with maximum diameter of the ascending aorta, and moderate correlation with ascending aortic Tortuosity. Adding tortuosity to the ATAAD prediction system will improve the ability to identify high-risk groups of ATAAD. When the tortuosity is more significant than 0.135, prophylactic surgical intervention should be considered.

Case Report: Morphological Characterization and Long-Term Observation of Bilateral Sequential Internal Mammary Artery Aneurysms in a Patient With Confirmed FBN1 Mutation

Marfan syndrome (MFS) is a genetically determined connective tissue disorder that leads to ocular, skeletal, and severe cardiovascular involvement. High mortality of MFS is associated with aortic dissection and aneurysm characteristic to the syndrome. In MFS, only a few cases of peripheral arterial involvement have been reported so far, mostly without a genetically confirmed diagnosis. We report a 41-year-old MFS patient with a saccular pearl-string-like aneurysm on the right internal mammary artery (RIMA) and a single aneurysm on the left internal mammary artery (LIMA). To our knowledge this is the first reported case on internal mammary artery aneurysms with this special morphology and with follow-up and blood pressure control as primary therapeutic approach in a patient with genetically confirmed MFS. The aneurysms with the above described morphology first appeared as small aneurysms on a CT scan 6 years after a cardiac operation. Due to the lack of guidelines, based on the asymptomatic state of the patient, the increased tortuosity of the affected vessels and the history of prior cardiac surgery, we decided to closely monitor these aneurysms with blood pressure control and without carrying out any interventions. On the CT scans done 3, 11, 12, 17, and 32 months after identifying the aneurysms, no progression of these structures was detected. Our findings confirm the possibility of the occurrence of internal mammary artery aneurysms in patients with FBN1 mutation and we believe that monitoring these aneurysms with blood pressure management can be a suitable option in selected cases.

The Iliofemoral tortuosity score predicts access and bleeding complications during transfemoral transcatheter aortic valve replacement: DataData from the VIenna Cardio Thoracic aOrtic valve registrY (VICTORY)

BACKGROUND

Arterial tortuosity is linked to a higher risk of adverse clinical events after transfemoral transcatheter aortic valve replacement (TF-TAVR). Currently, there are no assessment tools that can quantify this variable in three-dimensional space. This study investigated the impact of novel scoring methods of iliofemoral tortuosity on access and bleeding complications after TF-TAVR.

METHODS

The main access vessel was assessed between the aortoiliacal and femoral bifurcation in preoperative multislice computed tomography scans of 240 consecutive patients undergoing TF-TAVR. Tortuosity was assessed by three methods: largest single angle, sum of all angles, and iliofemoral tortuosity (IFT) score [((true vessel length/ideal vessel length)-1)*100]. The primary study endpoint was a composite of access and bleeding complications. The secondary study endpoints were 30-day mortality and long-term survival.

RESULTS

Among 240 patients, only the IFT score demonstrated a good positive correlation with the composite primary endpoint of access and bleeding complications (P = 0.031). A higher incidence of access and bleeding complications was found in patients with a higher IFT score (56 [36.8%] vs 17 [19.3%]; P = 0.003). In a multivariate logistic regression analysis, only the IFT score was a significant predictor of the primary endpoint (OR: 2.11; 95% CI: 1.09-4.05; P = 0.026).

CONCLUSION

Vascular tortuosity is an underestimated risk factor during TF-TAVR. The IFT score is a valuable tool in risk stratification before TF-TAVR, predicting periprocedural access and bleeding complications.

Potential predictors of severe cardiovascular involvement in Marfan syndrome: the emphasized role of genotype-phenotype correlations in improving risk stratification-a literature review

BACKGROUND

Marfan syndrome (MFS) is a genetically determined systemic connective tissue disorder, caused by a mutation in the FBN1 gene. In MFS mainly the cardiovascular, musculoskeletal and ocular systems are affected. The most dangerous manifestation of MFS is aortic dissection, which needs to be prevented by a prophylactic aortic root replacement.

MAIN BODY

The indication criteria for the prophylactic procedure is currently based on aortic diameter, however aortic dissections below the threshold defined in the guidelines have been reported, highlighting the need for a more accurate risk stratification system to predict the occurrence of aortic complications. The aim of this review is to present the current knowledge on the possible predictors of severe cardiovascular manifestations in MFS patients, demonstrating the wide range of molecular and radiological differences between people with MFS and healthy individuals, and more importantly between MFS patients with and without advanced aortic manifestations. These differences originating from the underlying common molecular pathological processes can be assessed by laboratory (e.g. genetic testing) and imaging techniques to serve as biomarkers of severe aortic involvement. In this review we paid special attention to the rapidly expanding field of genotype-phenotype correlations for aortic features as by collecting and presenting the ever growing number of correlations, future perspectives for risk stratification can be outlined.

CONCLUSIONS

Data on promising biomarkers of severe aortic complications of MFS have been accumulating steadily. However, more unifying studies are required to further evaluate the applicability of the discussed predictors with the aim of improving the risk stratification and therefore the life expectancy and quality of life of MFS patients.

Increased Internal Carotid Artery Tortuosity is a Risk Factor for Spontaneous Cervicocerebral Artery Dissection

OBJECTIVE

Spontaneous cervicocerebral artery dissection (sCCD) is an important cause of ischaemic stroke that often occurs in young and middle aged patients. The purpose of this study was to investigate the correlation between tortuosity of the carotid artery and sCCD.

METHODS

Patients with confirmed sCCD who underwent computed tomography angiography (CTA) were reviewed retrospectively. Age and sex matched patients having CTA were used as controls. The tortuosity indices of the cervical arteries were measured from the CTA images. The carotid siphon and the extracranial internal carotid artery (ICA) were evaluated according to morphological classification. The carotid siphons were classified into five types. The extracranial ICA was categorised as simple tortuosity, coiling or kinking. Independent risk factors for sCCD were investigated using multivariable analysis.

RESULTS

The study included sixty-six patients with sCCD and 66 controls. There were no differences in vascular risk factors between the two groups. The internal carotid tortuosity index (ICTI) (25.24 ± 12.37 vs. 15.90 ± 8.55, respectively; p < .001) and vertebral tortuosity index (VTI) (median 11.28; interquartile range [IQR] 6.88, 18.80 vs. median 8.38; IQR 6.02, 12.20, respectively; p = .008) were higher in the patients with sCCD than in the controls. Type III and Type IV carotid siphons were more common in the patients with sCCD (p = .001 and p < .001, respectively). The prevalence of any vessel tortuosity, coiling and kinking of the extracranial ICA was higher in the patients with sCCD (p < .001, p = .018 and p = .006, respectively). ICTI (odds ratio [OR] 2.964; p = .026), VTI (OR 5.141; p = .009), and Type III carotid siphons (OR 4.654; p = .003) were independently associated with the risk of sCCD.

CONCLUSION

Arterial tortuosity is associated with sCCD, and greater tortuosity of the cervical artery may indicate an increased risk of arterial dissection.

Neonatal Arterial Tortuosity and Adult Aortic Aneurysm-Is There a Missing Link?-A Case Report

We report a novel case of a full term newborn with non-immune fetal hydrops and arterial tortuosity mimicking a double aortic arch, and cranial fractures in the immediate neonatal period. The infant had no classic features of neonatal arterial tortuosity syndrome or Loeys Dietz syndrome apart from bilateral inguinal hernia. He also had skeletal manifestations in the form of fractures in the neonatal period without any trauma during birth and without clinical evidence of Osteogenesis Imperfecta. A heterozygous missense variant of uncertain significance was detected in MYH11 gene which is increasingly recognized to be belonging to the familial/hereditary thoracic aneurysm and aortic dissection group of disorders. Fetal hydrops as an association with arterial tortuosity has not been reported in the literature. We hypothesize the possible mechanism behind developing fetal hydrops in this case and discuss the genetic and phenotypic heterogeneity of the Familial Thoracic Aortic Aneurysm and Dissection (FTAAD) group of conditions highlighting the unique phenotypic and genotypic presentations. We recommend a high index of suspicion and vigilance in the early detection of such potentially lethal conditions with sequelae also in adulthood.

Pathogenic FBN1 Genetic Variation and Aortic Dissection in Patients With Marfan Syndrome

BACKGROUND

Aortic risk has not been evaluated in patients with Marfan syndrome and documented pathogenic variants in the FBN1 gene.

OBJECTIVES

This study sought to describe aortic risk in a population with Marfan syndrome with pathogenic variants in the FBN1 gene as a function of aortic root diameter.

METHODS

Patients carrying an FBN1 pathogenic variant who visited our reference center at least twice were included, provided they had not undergone aortic surgery or had an aortic dissection before their first visit. Aortic events (aortic surgery or aortic dissection) and deaths were evaluated during the 2 years following each patient visit. The risk was calculated as the number of events divided by the number of years of follow-up.

RESULTS

A total of 954 patients were included (54% women; mean age 23 years). During follow-up (9.1 years), 142 patients underwent prophylactic aortic root surgery, 5 experienced type A aortic dissection, and 12 died (noncardiovascular causes in 3, unknown etiology in 3, post-operative in 6). When aortic root diameter was <50 mm, risk for proven type A dissection (0.4 events/1,000 patient-years) and risk for possible aortic dissection (proven aortic dissection plus death of unknown cause, 0.7 events/1,000 patients-years) remained low in this population that was treated according to guidelines. Three type A aortic dissections occurred in this population during the 8,594 years of follow-up, including 1 in a patient with a tubular aortic diameter of 50 mm, but none in patients with a family history of aortic dissection. The risk for type B aortic dissection in the same population was 0.5 events/1,000 patient-years.

CONCLUSIONS

In patients with FBN1 pathogenic variants who receive beta-blocker therapy and who limit strenuous exercise, aortic risk remains low when maximal aortic diameter is <50 mm. The risk of type B aortic dissection is close to the remaining risk of type A aortic dissection in this population, which underlines the global aortic risk.

Mechanics-driven mechanobiological mechanisms of arterial tortuosity

Arterial tortuosity manifests in many conditions, including hypertension, genetic mutations predisposing to thoracic aortopathy, and vascular aging. Despite evidence that tortuosity disrupts efficient blood flow and that it may be an important clinical biomarker, underlying mechanisms remain poorly understood but are widely appreciated to be largely biomechanical. Many previous studies suggested that tortuosity may arise via an elastic structural buckling instability, but the novel experimental-computational approach used here suggests that tortuosity arises from mechanosensitive, cell-mediated responses to local aberrations in the microstructural integrity of the arterial wall. In particular, computations informed by multimodality imaging show that aberrations in elastic fiber integrity, collagen alignment, and collagen turnover can lead to a progressive loss of structural stability that entrenches during the development of tortuosity. Interpreted in this way, microstructural defects or irregularities of the arterial wall initiate the condition and hypertension is a confounding factor.

Diagnostic approach and management of genetic aortopathies

Aortic aneurysms were the primary cause of nearly 10,000 deaths in 2014 according to data from the Centers for Disease Control and may involve segments of the thoracic or abdominal aorta. Thoracic aortic aneurysms and dissections are more commonly associated with an underlying genetic etiology. In the past several decades, in parallel with the burst of new genome sequencing technologies, a number of genetic aortopathies have been identified. These have provided important insights into the molecular mechanisms of aneurysmal disease, but pose challenges in clinical practice as there are limited consensus recommendations at this time. In this review, we aim to address the pathophysiology, clinical presentation, and treatment considerations in the key heritable thoracic aortopathies.

Intracranial Arterial Tortuosity in Marfan Syndrome and Loeys-Dietz Syndrome: Tortuosity Index Evaluation Is Useful in the Differential Diagnosis

BACKGROUND AND PURPOSE

The association of arterial tortuosity and connective tissue diseases is widely reported in the literature, but only a few studies were based on a quantitative evaluation of this arterial phenotype, and none of the latter examined the intracranial vasculature. The aim of this study was to evaluate the degree of intracranial arterial tortuosity in patients with Marfan syndrome and those with Loeys-Dietz syndrome, and to assess its usefulness in the differential diagnosis.

MATERIALS AND METHODS

We performed a retrospective analysis of 68 patients with genetically confirmed Marfan syndrome (n = 36) or Loeys-Dietz syndrome (n = 32), who underwent at least 1 MRA of the brain at our institution. Fifty-two controls were randomly selected among patients who presented with headache and without any known comorbidity. Tortuosity indexes of 4 intracranial arterial segments were measured on a 3D volume-rendered angiogram by using the following formula: [Formula: see text].

RESULTS

Both Marfan syndrome and Loeys-Dietz syndrome showed a significantly higher tortuosity index compared with controls in all examined vessels. The tortuosity index of the vertebrobasilar system showed an excellent interrater reliability (intraclass correlation coefficient, 0.99) and was the strongest independent predictor of Loeys-Dietz syndrome in patients with connective tissue disease (P = .002), with a 97% specificity for this pathology when its value was > 60.

CONCLUSIONS

The tortuosity index of intracranial arteries is an easily calculated and highly reproducible measure, which shows a high specificity for Marfan syndrome and Loeys-Dietz syndrome and may be useful in differentiating these 2 entities.

Are Genetic Variants Associated with the Location of Cerebral Arterial Lesions in Stroke Patients?

BACKGROUND

Genetic variants may play a role in determining the location of cerebral atherosclerosis. We aimed to investigate the association between RNF213, MMP2, and genetic polymorphisms linked to vascular tortuosity with the location of cerebral arterial atherosclerosis.

METHODS

A prospective case-control study was conducted on patients with ischemic stroke and age- and sex-matched stroke-free controls. The stroke patients were categorized into those with intracranial artery atherosclerosis (ICAS), extracranial artery atherosclerosis (ECAS), and small vessel occlusion (SVO). Six single nucleotide polymorphisms (SNPs) including rs2118181 (FBN1), rs2179357 (SLC2A10), rs1036095 (TGFBR2), rs243865 (MMP2), rs1800470 (TGFB1), and rs112735431 (RNF213) were analyzed with the TaqMan Genotyping Assay, and the distribution of genotypes across groups was compared.

RESULTS

None of the 6 SNPs were associated with stroke on comparing the 449 stroke patients (71 with ECAS, 169 with ICAS, and 209 with SVO) to the 447 controls. In the subgroup analysis, the adjusted odds ratios (aORs) for age and sex indicated a significant association between rs112735431 and ICAS in the allele comparison analysis and in the additive and dominant model analyses. rs112735431 was associated with anterior circulation involvement and increased burden of cerebral atherosclerosis. rs2179357 was significantly associated with ICAS in the recessive model analysis, and rs1800470 was significantly associated with ECAS in the recessive model analysis when compared to controls.

CONCLUSION

rs112735431 was associated with ICAS and increased atherosclerosis burden in Korean stroke patients. Further studies are needed to elucidate the role of rs112735431 and to confirm the association of rs2179357 and rs1800470 with cerebral atherosclerosis.

Increased visceral arterial tortuosity in Marfan syndrome

BACKGROUND

Clinical evidence suggests that the currently recommended approach to estimate the risk of aortic dissection in Marfan syndrome (MFS) is not reliable enough. Therefore, we investigated the possible role of visceral arterial tortuosity in the risk stratification.

METHODS AND RESULTS

Splenic and renal arteries of 37 MFS patients and 74 age and gender matched control subjects were segmented using CT angiography imaging. To measure tortuosity, distance metric (DM), sum of angles metric (SOAM), inflection count metric (ICM), and the ratio of ICM and SOAM (ICM/SOAM) were calculated. DM of the splenic, right and left renal artery was significantly higher in MFS patients than in controls (2.44 [1.92-2.80] vs. 1.75 [1.57-2.18] p < 0.001; 1.16 [1.10-1.28] vs. 1.11 [1.07-1.15] p = 0.011; 1.40 [1.29-1.70] vs. 1.13 [1.09-1.23] p < 0.001, respectively). A similar tendency for ICM and an opposite tendency for SOAM were observed. ICM/SOAM was significantly higher in the MFS group compared to controls in case of all three arteries (73.35 [62.26-93.63] vs. 50.91 [43.19-65.62] p < 0.001; 26.52 [20.69-30.24] vs. 19.95 [16.47-22.95] p < 0.001; 22.81 [18.64-30.96] vs. 18.38 [15.29-21.46] p < 0.001, respectively). MFS patients who underwent aortic root replacement had increased right and left renal DM and ICM/SOAM compared to MFS patients without surgery.

CONCLUSION

To our knowledge this is the first demonstration of increased arterial tortuosity in MFS on visceral arteries. Visceral arterial tortuosity, dominated by curves of lower frequency but higher amplitude according to the observed opposite tendency between the DM and SOAM metrics, could be a possible new predictor of serious manifestations of MFS.

First international consensus on the diagnosis and management of fibromuscular dysplasia

This article is a comprehensive document on the diagnosis and management of fibromuscular dysplasia (FMD) which was commissioned by the Working Group 'Hypertension and the Kidney' of the European Society of Hypertension (ESH) and the Society for Vascular Medicine (SVM). This document updates previous consensus documents/scientific statements on FMD published in 2014 with full harmonization of the position of European and US experts. In addition to practical consensus-based clinical recommendations, including a consensus protocol for catheter-based angiography and percutaneous angioplasty for renal FMD, the document also includes the first analysis of the European/International FMD Registry and provides updated data from the US Registry for FMD. Finally, it provides insights on ongoing research programs and proposes future research directions for understanding this multifaceted arterial disease.

Clinical variability in children with dolichoarteriopathies of the internal carotid artery

INTRODUCTION

Dolichoarteriopathies of the internal carotid artery (DICA) are frequent non-atheromatous anatomical changes in the general population. The etiology of DICA is still controversial: several hypotheses have been suggested, including an anomaly of embryological development, or a degenerative loss of elasticity of the vessel wall. DICA have been related to a wide spectrum of clinical presentations in adults, varying from asymptomatic forms to acute cerebrovascular events. However, to date, only a few pediatric cases have been reported.

METHODS AND RESULTS

We report seven patients with DICA, 6 males and 1 female, aged 3 to 13 years, presenting with variable clinical symptoms. Different imaging techniques, including color Doppler ultrasound and magnetic resonance angiography, were used to show loops and/or kinking of the ICA. Three of these patients received a diagnosis of Ehlers-Danlos syndrome (EDS).

DISCUSSION

This study highlights the clinical variability in pediatric patients with DICA. We emphasize the need for close clinical management of pediatric DICA. Finally, considering the long-term prognostic implications of EDS, we recommend specific testing in children with DICA and suspicious clinical signs of this pathology.

CD73 (Cluster of Differentiation 73) and the Differences Between Mice and Humans

As vascular disease is complex and the various manifestations are influenced by differences in vascular bed architecture, exposure to shear and mechanical forces, cell types involved, and inflammatory responses, in vivo models are necessary to recapitulate the complex physiology and dynamic cellular interactions during pathogenesis. Murine knockout models are commonly used tools for investigators to study the role of a specific gene or pathway in multifaceted disease traits. Although valuable, these models are not perfect, and this is particularly true in regard to CD73 (cluster of differentiation 73), the extracellular enzyme that generates adenosine from AMP. At baseline, CD73-deficient mice do not present with an overt phenotype, whereas CD73-deficient humans present with the complex phenotype of vascular calcification, arteriomegaly and tortuosity, and calcification in small joints. In this review, we highlight the differences between the mouse and human systems and discuss the potential to leverage findings in mice to inform us on the human conditions.

Genetics and Precision Medicine: Heritable Thoracic Aortic Disease

Heritable thoracic aortic disease (HTAD) can have life-threatening consequences if not diagnosed early. Affected individuals and at-risk family members benefit from both cardiology and genetic evaluations, including genetic testing. Important information can be obtained through family history, medical history, and genetic testing to help guide management and assess risk. A genetic diagnosis can guide cardiovascular management (type and frequency of vascular imaging, timing of surgical intervention), risk assessment for arterial aneurysm/dissection, evaluation of nonvascular features, and familial testing.

First International Consensus on the diagnosis and management of fibromuscular dysplasia

This article is a comprehensive document on the diagnosis and management of fibromuscular dysplasia (FMD), which was commissioned by the working group ‘Hypertension and the Kidney’ of the European Society of Hypertension (ESH) and the Society for Vascular Medicine (SVM). This document updates previous consensus documents/scientific statements on FMD published in 2014 with full harmonization of the position of European and US experts. In addition to practical consensus-based clinical recommendations, including a consensus protocol for catheter-based angiography and percutaneous angioplasty for renal FMD, the document also includes the first analysis of the European/International FMD Registry and provides updated data from the US Registry for FMD. Finally, it provides insights on ongoing research programs and proposes future research directions for understanding this multifaceted arterial disease.

Decreased Nuclear Ascorbate Accumulation Accompanied with Altered Genomic Methylation Pattern in Fibroblasts from Arterial Tortuosity Syndrome Patients

Ascorbate requiring Fe²⁺/2-oxoglutarate-dependent dioxygenases located in the nucleoplasm have been shown to participate in epigenetic regulation of gene expression via histone and DNA demethylation. Transport of dehydroascorbic acid is impaired in the endomembranes of fibroblasts from arterial tortuosity syndrome (ATS) patients, due to the mutation in the gene coding for glucose transporter GLUT10. We hypothesized that altered nuclear ascorbate concentration might be present in ATS fibroblasts, affecting dioxygenase activity and DNA demethylation. Therefore, our aim was to characterize the subcellular distribution of vitamin C, the global and site-specific changes in 5-methylcytosine and 5-hydroxymethylcytosine levels, and the effect of ascorbate supplementation in control and ATS fibroblast cultures. Diminished nuclear accumulation of ascorbate was found in ATS fibroblasts upon ascorbate or dehydroascorbic acid addition. Analyzing DNA samples of cultured fibroblasts from controls and ATS patients, a lower global 5-hydroxymethylcytosine level was found in ATS fibroblasts, which could not be significantly modified by ascorbate addition. Investigation of the (hydroxy)methylation status of specific regions in six candidate genes related to ascorbate metabolism and function showed that ascorbate addition could stimulate hydroxymethylation and active DNA demethylation at the PPAR-γ gene region in control fibroblasts only. The altered DNA hydroxymethylation patterns in patient cells both at the global level and at specific gene regions accompanied with decreased nuclear accumulation of ascorbate suggests the epigenetic role of vitamin C in the pathomechanism of ATS. The present findings represent the first example for the role of vitamin C transport in epigenetic regulation suggesting that ATS is a compartmentalization disease.

Comparability of semiautomatic tortuosity measurements in the carotid artery

Purpose

Increased arterial tortuosity has been suggested as a predisposing factor for carotid artery dissection, which is an important risk factor for development of extracranial carotid artery aneurysms (ECAA). Prior to comparison with non-ECAA controls, the optimal measurement technique should be defined. This study describes the difference between software packages in terms of reproducibility and absolute outcome of arterial tortuosity measurements in ECAA patients.

Methods

CT-angiography analysis was performed on 12 ECAA patients selected from our registry, using four software packages: 3mensio Vascular, TeraRecon, Vital Images, and Aycan OsiriX PRO. The tortuosity index (TI) was calculated from the skull base until the carotid bifurcation and aortic arch, and was defined as the centerline’s true length divided by the straight line distance. Intraclass correlation coefficients (ICC) with 95% confidence intervals were calculated to quantify inter- and intra-observer variability within one software package, and differences in measured TI between packages.

Results

Inter-observer agreement was nearly perfect for 3mensio, excellent for Vital Images and OsiriX, and substantial for TeraRecon, with ICC 0.99 (0.96–1.0), 0.90 (0.69–0.97), 0.84 (0.53–0.95), and 0.72 (0.28–0.91), respectively. Intra-observer agreement ranged from ICC 1.0 for 3mensio to 0.91 for TeraRecon. Agreements in TI ranged from ICC 0.99 (0.98–1.0) for 3mensio vs. OsiriX, to 0.95 (0.82–0.98) for 3mensio vs. TeraRecon. Median time needed to complete one round of measurements was highest for OsiriX (p = 0.013).

Conclusions

Carotid artery tortuosity measurements are reproducible and comparable between current commercially available software packages, with high intra-observer agreement. Although the reproducibility differed per software packages, all packages scored an acceptable inter-observer agreement.

Aortic arch tortuosity, a novel biomarker for thoracic aortic disease, is increased in adults with bicuspid aortic valve

INTRODUCTION

Arterial tortuosity has emerged as a predictor of adverse outcomes in congenital aortopathies using 3D reconstructed images. We validated a new method to estimate aortic arch tortuosity on 2D CT. We hypothesize that arch tortuosity may identify bicuspid aortic valve (BAV) patients at high risk to develop thoracic aortic aneurysms or aortic dissections (TAD).

METHODS

BAV subjects with chest CT scans were retrospectively identified in our clinical records and matched to tricuspid aortic valve (TAV) controls by age, gender, and presentation with TAD. Subjects with prior ascending aortic intervention were excluded. Measurements included aortic arch tortuosity, length, angle, width and height. Total aortic tortuosity was estimated in subjects with available abdominal images.

RESULTS

120 BAV and 234 TAV subjects were included. Our 2D measurements were highly correlated with 3D midline arch measurements and had high inter- and intra-observer reliability. Compared to TAV, BAV subjects had increased arch tortuosity (median 1.76 [Q1-Q3: 1.62-1.95] vs. 1.63 [1.53-1.78], P < 0.01), length (149 [136-160] vs. 135 [122-152] mm, P < 0.01), height (46 [41-53] vs. 39 [34-47] mm, P < 0.01), and vertex acuity (70 [61-77] vs. 75 [68-81] degree, P < 0.01). In a multivariable analysis, arch tortuosity remained independently associated with BAV after adjusting for aortic diameter and other clinical characteristics.

CONCLUSIONS

We found that aortic arch tortuosity is significantly increased in BAV and may identify BAV patients who are at increased risk for TAD. Further studies to evaluate the association between tortuosity and clinical outcomes are in progress.

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.

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.

Vertebral Tortuosity Index in Patients with Non-Connective Tissue Disorder-Related Aneurysm Disease

OBJECTIVE

The vertebral tortuosity index (VTI) predicts increased risk of acute aortic events in patients with known genetic aortopathies. This study describes the VTI in a cohort of patients with non-connective tissue disorder-related large aneurysms.

METHODS

Hospital imaging records from July 2012 to March 2016 were interrogated to identify patients with aneurysmal disease who had undergone computed tomographic angiography that included imaging of vertebral arteries. A control group of consecutive patients undergoing carotid and vertebral imaging was also assessed. VTI was calculated using the formula: [(centre-line distance) / (straight-line distance)-1] ×100 for all patients, and statistical analysis undertaken to determine whether measured VTI was statistically different in patients of younger age, with larger aneurysms, or an acute presentation. Comparison was made with patients who had no aneurysm disease.

RESULTS

Sixty-five patients were identified with adequate imaging to assess the entire aorta, including vertebral arteries. The majority of patients were male (71%, 46/65) and mean age at the time of the CT scan was 71 years (SD 11.1 years). There were 11 patients under the age of 60 years in this cohort. The mean VTI was 33.17 (SD 20.43). There was no statistically significant difference between different territories of presentation (proximal vs. distal aneurysm, p=.94), age of patient (>60 years vs. <60 years, p=.2), or size of aneurysm (>6 cm vs. <6 cm, p=.09). Acuity of presentation was not predicted by a higher VTI (p=.69). The VTI in patients with aneurysms was higher than in patients without aneurysm disease (VTI = 16.1, p<.005) CONCLUSIONS: An elevated VTI is consistently present in patients with degenerative aneurysms and has potential as a universally available predictive measurement. However, the increased VTI in the older cohort without connective tissue disease may not carry the same predictive value for acute presentations as has been demonstrated in younger patients with a known genetic basis for their aortopathy.

Function of Ltbp-4L and fibulin-4 in survival and elastogenesis in mice

LTBP-4L and LTBP-4S are two isoforms of the extracellular matrix protein latent-transforming growth factor beta-binding protein 4 (LTBP-4). The mutational inactivation of both isoforms causes autosomal recessive cutis laxa type 1C (ARCL1C) in humans and an ARCL1C-like phenotype in Ltbp4^-/- mice, both characterized by high postnatal mortality and severely affected elastogenesis. However, genetic data in mice suggest isoform-specific functions for Ltbp-4 because Ltbp4S^-/- mice, solely expressing Ltbp-4L, survive to adulthood. This clearly suggests a requirement of Ltbp-4L for postnatal survival. A major difference between Ltbp4S^-/- and Ltbp4^-/- mice is the matrix incorporation of fibulin-4 (a key factor for elastogenesis; encoded by the Efemp2 gene), which is normal in Ltbp4S^-/- mice, whereas it is defective in Ltbp4^-/- mice, suggesting that the presence of Ltbp-4L might be required for this process. To investigate the existence of a functional interaction between Ltbp-4L and fibulin-4, we studied the consequences of fibulin-4 deficiency in mice only expressing Ltbp-4L. Resulting Ltbp4S^-/-;Fibulin-4^R/R mice showed a dramatically reduced lifespan compared to Ltbp4S^-/- or Fibulin-4^R/R mice, which survive to adulthood. This dramatic reduction in survival of Ltbp4S^-/-;Fibulin-4^R/R mice correlates with severely impaired elastogenesis resulting in defective alveolar septation and distal airspace enlargement in lung, and increased aortic wall thickness with severely fragmented elastic lamellae. Additionally, Ltbp4S^-/-;Fibulin-4^R/R mice suffer from aortic aneurysm formation combined with aortic tortuosity, in contrast to Ltbp4S^-/- or Fibulin-4^R/R mice. Together, in accordance with our previous biochemical findings of a physical interaction between Ltbp-4L and fibulin-4, these novel in vivo data clearly establish a functional link between Ltbp-4L and fibulin-4 as a crucial molecular requirement for survival and elastogenesis in mice.