Intracranial Aneurysm Is Associated with High Intracranial Artery Tortuosity

Vessel wall MRI evaluation for the safety of endovascular recanalization of non-acute intracranial anterior circulation artery occlusions

BACKGROUND

Vessel wall MRI (VWMRI) can reveal the morphological features of intracranial artery occlusion (ICAO). This study aimed to investigate the imaging features of ICAO on VWMRI and explore their correlation with perioperative complications of endovascular recanalization for non-acute ICAO.

METHODS

The study retrospectively included consecutive patients with recurrent ischemic stroke due to non-acute ICAO in the anterior circulation who underwent preoperative VWMRI evaluation and endovascular recanalization. Perioperative complications included ischemic and hemorrhagic strokes within 30 days after operation. Imaging features of the occluded segments were evaluated on precontrast and post-contrast VWMRI, including occlusion length and site, vessel wall area, signal intensity, angle, and shape of the occluded segment. The associations between the clinical and imaging features and perioperative complications were examined.

RESULTS

One hundred and four patients were included in the analysis, of whom 22.1% (23/104) had perioperative complications. After adjusting for multiple confounding variables, four imaging risk factors were identified that were independently associated with perioperative complications, that is, the angle between the occluded and pre-occluded artery segments (OR 11.60, 95% CI 2.73 to 49.29), occluded artery segment shape (OR 13.07, 95% CI 2.82 to 60.67), vessel wall collapse before occlusion (OR 2.91, 95% CI 0.96 to 8.77), and post-contrast mean signal intensity ratio at the ¼ point of the occluded artery segment <1.24 (OR 6.14, 95% CI 1.67 to 22.51). From no risk factors to four risk factors, the incidence of perioperative complications gradually increased (0, 6.2%, 23.5%, 52.9%, and 100% respectively; p<0.001).

CONCLUSIONS

VWMRI may be helpful to select patients with non-acute ICAO who are suitable for endovascular recanalization.

Hemodynamic Effects of Tortuosity and Stenosis in Superficial Temporal Artery-Middle Cerebral Artery Bypass for Moyamoya Disease

BACKGROUND

Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery has been widely adopted in treating moyamoya disease (MMD). Geometric variations including high tortuosity and stenosis exist in many cases, but the hemodynamic effects have not been comprehensively evaluated. We aim to evaluate the hemodynamic effects of bypass geometry variations based on patient-specific data.

METHODS

In total, 17 patients with MMD who underwent STA-MCA bypass surgery with highly tortuous bypass geometry were included. For each patient, the original 3-dimensional structure of STA-MCA bypass was reconstructed from clinical imaging data. The bypass structure was virtually improved by removing the tortuosity and stenosis. Computational fluid dynamics simulation was performed on both bypass structures under identical patient-specific condition. The simulated hemodynamic parameters of the bypass and its distal branches were compared between the original and virtually improved bypass geometries in all cases using paired t-test or Wilcoxon signed-rank test. The changes of hemodynamic parameters were compared between the cases with and without mild-to-moderate stenosis (44.0-70.3% in diameter) in the bypass using t-test or Mann-Whitney U test.

RESULTS

The virtual improvement of bypass geometry significantly increased the flow rate of the bypass and its distal branches (P < 0.05) and decreased the transcranial flow resistance (P < 0.05). The hemodynamic changes in cases with stenosis removal were significantly greater than those without stenosis (P < 0.05).

CONCLUSIONS

High tortuosity and stenosis can significantly change the hemodynamics of STA-MCA bypass, and the optimization of bypass geometry deserves further consideration.

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.

Association of Arterial Tortuosity with Hemodynamic Parameters-A Computational Fluid Dynamics Study

BACKGROUND

Tortuosity of intracranial arteries has been proven to be associated with the risk of intracranial aneurysm development. We decided to analyze which aspects of tortuosity are correlated with hemodynamics parameters promoting intracranial aneurysm development.

METHODS

We constructed 73 idealized models of tortuous artery (length: 25 mm, diameter: 2.5 mm) with single bifurcation. For each model, on the course of segment before bifurcation, we placed 1-3 angles with measures 15, 30, 45, 60, or 75 degrees and arc lengths 2, 5, 7, 10, or 15 mm. We performed computational fluid dynamics analysis. Blood was modeled as Newtonian fluid. We have set velocity wave of 2 cardiac cycles. After performing simulation we calculated following hemodynamic parameters at the bifurcation: time average wall shear stress (TAWSS), time average wall shear stress gradient (TAWSSG), oscillatory shear index (OSI), and relative residence time (RRT).

RESULTS

We found a significant positive correlation with number of angles and TAWSS (R = 0.329; P < 0.01), TAWSSG (R = 0.317; P < 0.01), and negative with RRT (R = -0.335; P < 0.0.01). Similar results were obtained in terms of arcs lengths. On the other hand, mean angle measure was negatively correlated to TAWSS (R = -0.333; P < 0.01), TAWSSG (R = -0.473 P < 0.01), OSI (R = -0.463; P < 0.01), and positively to RRT (R = 0.332; P < 0.01). On the basis of the obtained results, we developed new tortuosity descriptor, which considered angle measures normalized to its arc length and distance from bifurcation. For such descriptor we found strong negative correlation with TAWSS (R = -0.701; P < 0.01), TAWSSG (R = 0.778; P < 0.01), OSI (R = -0.776; P < 0.01), and positive with RRT (R = 0.747; P < 0.01).

CONCLUSIONS

Hemodynamic parameters promoting aneurysm development are correlated with larger number of smaller angles located on larger arcs.

Unilateral cerebral arterial tortuosity: Associated with aneurysm occurrence, but potentially inversely associated with aneurysm rupture

PURPOSE

To investigate the association of tortuosity of the main cerebral arteries with intracranial aneurysm (IA) occurrence and rupture. To investigate the relationship between arterial tortuosity and aneurysm morphology as well as conventional risk factors of vascular diseases.

METHODS

Three subject groups were analyzed in this study: Patients with ruptured IAs, patients with unruptured IAs, and healthy subjects. The groups were matched by sex and age using tendency score matching. Their intracranial magnetic resonance angiography (MRA) images were collected retrospectively. The intracranial arterial structures were segmented from the MRA images. Arterial tortuosity was measured and statistically compared between the different subject groups and different vessels. Correlation analysis was conducted between arterial tortuosity and clinical risk factors as well as aneurysm morphology.

RESULTS

120 patients were included in the study (average age: 67.5 years; 60% female), 40 for each group after matching. The tortuosity of the aneurysm-bearing artery was significantly greater than that of the contralateral artery in both the ruptured and unruptured IA groups (p < 0.001). There was no significant association between clinical risk factors (history of hypertension, hyperlipidemia, diabetes, smoking, and alcohol use) and arterial tortuosity. There were significant negative correlations between aneurysm-bearing artery tortuosity and aneurysm morphological features such as maximal diameter (p = 0.0011), neck diameter (p < 0.0001), maximum height (p = 0.0024), and size ratio (p = 0.0269).

CONCLUSION

The occurrence of cerebral aneurysms correlates to increased unilateral arterial tortuosity, but the risk of aneurysm enlargement/rupturing decreases with greater arterial tortuosity. Abnormal tortuosity may be congenital as tortuosity has no clear connection with acquired common risk factors of vascular diseases.

Carotid tortuosity is associated with extracranial carotid artery aneurysms

BACKGROUND

Tortuous arteries may be associated with carotid dissection. The intima disruption caused by a carotid dissection is a possible cause of extracranial carotid artery aneurysms (ECAAs). The aim was to investigate if carotid tortuosity is also associated with ECAA in patients without presence or history of a carotid artery dissection.

METHODS

A retrospective case-control study was performed including 35 unilateral ECAA patients (cases) and 105 age- and sex-matched controls. Tortuosity was expressed as tortuosity-index (TI), curvature, and torsion measured on computed tomography angiography (CTA) data in 3Mensio Vascular and MATLAB by two independent investigators. Primary comparison was tortuosity in ipsi- versus contralateral carotid artery within the cohort of ECAA patients. Secondary comparison was tortuosity with ipsilateral carotid arteries in control patients. All observations were assessed on inter- and intra-operator reproducibility.

RESULTS

Carotid tortuosity was comparable within the cohort of ECAA patients (Spearman correlation 0.76, P<0.001), yet distinctively higher in comparison with unilateral controls. After adjustment for patient characteristics, presence of ECAA was associated with TI (β 0.146, 95% CI: 0.100-0.192). All tortuosity observations showed excellent inter- and intra-operator reproducibility.

CONCLUSIONS

Carotid tortuosity seems to be a risk factor for development of ECAA. Surveillance of individuals with increased carotid tortuosity therefore potentially ensures prompt diagnosis and treatment of ECAA. However, future research should investigate if persons with an increased tortuosity do indeed develop ECAA.

Tortuosity of parent artery predicts in-stent stenosis after pipeline flow-diverter stenting for internal carotid artery aneurysms

Background and purpose

The relationship between the tortuosity of the parent artery and treatment outcomes is not well established. We investigate the association between parent artery tortuosity and flow diverter (FD) treatment outcomes in patients with internal carotid artery aneurysms in this study.

Methods

A retrospective review study was conducted to identify all patients with internal carotid artery aneurysms who were implanted with Pipeline embolization device (PED) between 2016 and 2020. The relationship between parent artery tortuosity and aneurysm complete occlusion (CO) and in-stent stenosis (ISS) was analyzed. The mathematical parameters “Curvature”, “torsion”, and “DM” extracted from the parent artery were utilized to quantify the parent artery tortuosity. A vascular narrowing of greater than 25% was categorized as ISS. Logistic regression analysis was used to identify significant independent predictors. Furthermore, we compared the performance of four machine learning algorithms and Logistic Regression model in predicting ISS.

Results

This research included 62 patients who with internal carotid artery aneurysms. In 49 (79%) cases, follow-up angiography (mean follow-up duration 11.7 ±7.3 months) revealed CO of the aneurysm. ISS was detected in 22 (35.5%) cases. According to univariate analysis, parent artery tortuosity and other variables were not associated with CO (p > 0.1). Maximum curvature (OR = 1.084; 95% CI, 1.008–1.165; p = 0.03) and DM (OR = 0.01; 95% CI, 0–0.488; p = 0.02) exhibited strong independent associations with ISS in multivariate analysis. The SVM model is superior to the conventional Logistic Regression model and the other models in predicting ISS.

Conclusions

The tortuosity of the parent artery may affect the treatment outcome of FD stenting. We found that parent artery tortuosity was associated with ISS, but not with aneurysm complete occlusion following PED stenting for internal carotid artery aneurysms in this study. Parent arteries with higher maximum curvature and lower DM were more likely to develop ISS.

Subarachnoid Hemorrhage from Ruptured Internal Carotid Artery Aneurysm: Association with Arterial Tortuosity

OBJECTIVE

Many researchers have found a correlation between tortuous arteries and development of aneurysms in cerebral arteries. We decided to determine whether tortuosity of the internal carotid artery can be related to its aneurysm rupture.

METHODS

We retrospectively analyzed the internal carotid artery anatomy of 149 patients with internal carotid artery aneurysms. For each patient, we calculated relative length (RL), sum of angle metrics (SOAM), triangular index (TI), product of angle distance (PAD), and inflection count metrics (ICM).

RESULTS

A total of 33 patients (22.15%) had subarachnoid hemorrhage. These patients had significantly lower SOAM (0.31 ± 0.17 vs. 0.42 ± 0.21; P < 0.01), TI (0.27 ± 0.09 vs. 0.31 ± 0.11; P = 0.03) and ICM (0.25 ± 0.11 vs. 0.31 ± 0.17; P = 0.04). In multivariate logistic regression analysis, higher SOAM (odds ratio, 0.780; 95% confidence interval, 0.619-0.961; P = 0.025) remained independently associated with lower risk of internal carotid artery aneurysm rupture. In addition, we found significant positive correlation of aneurysm dome size with SOAM (R = 0.224; P = 0.013) and PAD (0.269; P < 0.01). Our study also showed that age (R = 0.252; P = 0.036), Glasgow Coma Scale score (R = -0.706; P < 0.01), and TI (R = -0.249; P = 0.042) were independently correlated with modified Rankin Scale score on discharge.

CONCLUSIONS

Lower tortuosity might be a protective factor against internal carotid artery aneurysm rupture and poor outcome after subarachnoid hemorrhage. Higher tortuosity is correlated with internal carotid artery aneurysm growth.

Venous tortuosity as a novel biomarker of rupture risk in arteriovenous malformations: ARI score

BACKGROUND

Risk of rupture in arteriovenous malformations (AVMs) varies considerably among series. Hemodynamic factors, especially within the venous side of the circuit, seem to be responsible but are not yet well defined. We analyzed tortuosity in the draining vein as a potential new marker of rupture in AVMs, and propose a simple index to predict AVM bleeding.

METHODS

A retrospective analysis of the venous angioarchitecture of brain AVMs was carried out at our center from 2013 to 2021, with special attention to venous tortuosity. After univariate analysis, the features of interest were combined to construct several predictive models using multivariate logistic regression. The best model proposed was the new AVM rupture index (ARI), which was then validated in an independent cohort.

RESULTS

68 AVMs were included in the first step and 32 in the validation cohort. Venous tortuosity, expressed as at least one curve >180°, was a significant predictor of rupture (p=0.023). The proposed bleeding index consisted of: venous tortuosity (any curve of >180°), single draining vein, and paraventricular/infratentorial location. It seems to be a robust evaluation tool, with an area under the receiver operating characteristic (AUROC) curve of 0.806 (95% CI 0.714 to 0.899), consistently replicated in the independent sample (AUROC 0.759 (95% CI 0.607 to 0.911)), and with an inter-rater kappa coefficient of 0.81 .

CONCLUSIONS

Venous tortuosity may serve as a predictor of bleeding in AVMs that warrants further investigation. This likely new marker was one of the three elements of the proposed ARI. ARI outperformed the predictive accuracy of previous scores, and remained consistent in an independent cohort.

Imaging markers of intracranial aneurysm development: A systematic review

BACKGROUND

Imaging markers of intracranial aneurysm (IA) development are not well established.

PURPOSE

To provide an overview of imaging markers of IA development.

METHODS

A systematic search of PubMed and Embase up to December 1st 2020 using predefined criteria. Thirty-six studies met our inclusion criteria. We performed a quantitative summary of the included studies.

RESULTS

We found converging evidence for A1 segment asymmetry as an anatomical marker of anterior communicating artery (Acom) aneurysm development, and moderate evidence for several other markers. No hemodynamic markers yielded converging or moderate evidence. There was large heterogeneity across studies, especially in the definitions of imaging markers and study outcomes used. Due to the poor methodological quality of many studies and unavailability of effect sizes or crude data to calculate effect sizes, a formal meta-analysis was not possible. Many studies had poor methodological quality and varied inmarkerdefinitions and outcome measuresused, which prevented us from performing a formal meta-analysis.

CONCLUSIONS

We only identified A1 segment asymmetry as an imaging marker of Acom aneurysm development with converging evidence. A meta-analysis was not possible due to the heterogeneity of marker definitions and outcomes used, and poor methodological quality of many studies. Future studies should use robust study designs and uniformly defined imaging markers and outcome measures.

How Cerebral Vessel Tortuosity Affects Development and Recurrence of Aneurysm: Outer Curvature versus Bifurcation Type

Background and Purpose

Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA.

Methods

We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space.

Results

Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels.

Conclusions

TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.

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.

Increased tortuosity of basilar artery might be associated with higher risk of aneurysm development

Objectives

We analysed tortuosity of basilar artery (BA) to determine its relationship with the presence of aneurysm.

Methods

We retrospectively analysed 71 patients with BA aneurysms along with 71 age- and risk factors-matched control patients without BA aneurysm. From patients’ medical records, we obtained their history including previous and current diseases and medications. For each patient, we calculated relative length (RL), sum of angle metrics (SOAM), triangular index (TI), product of angle distance (PAD) and inflexion count metrics (ICM). We used t-test and Mann-Whitney U test for continuous variables and χ² test for dichotomised variables. To find independent predictors of BA aneurysm, we employed logistic regression analysis.

Results

We found significant positive correlation between age and SOAM (R = 0.195, p = 0.02) and PAD (R = 0.199, p = 0.018). Our study also showed that patients with BA aneurysm had significantly higher SOAM (0.21 ± 0.16 vs. 0.11 ± 0.08; p < 0.01), PAD (0.30 ± 0.19 vs. 0.18 ± 0.11; p < 0.01), TI (0.23 ± 0.23 vs. 0.10 ± 0.16; p < 0.01) and ICM (0.20 ± 0.16 vs. 0.15 ± 0.11; p = 0.045). In multivariate logistic regression analysis, after adjustment for all possible confounders, SOAM (OR = 1.086; 95% CI 1.046–1.136; p < 0.01) and TI (OR = 1.004; 95%C: 1.002–1.006; p < 0.01) remained independently associated with higher risk of BA aneurysm.

Conclusions

Increased tortuosity of BA is associated with higher risk of its aneurysm development.

Key Points

• Basilar artery sum of angle metrics and product of angle distance are correlated with age.

• Basilar artery tortuosity is independently associated with higher risk of its aneurysm development.

• Basilar artery tortuosity is positively correlated with its diameter and bifurcation angle.

Neurovascular findings in children and young adults with Loeys-Dietz syndromes: Informing recommendations for screening

INTRODUCTION

Loeys-Dietz Syndromes (LDS) are a group of connective tissue disorders associated with vascular abnormalities, including arterial tortuosity, aneurysms, and dissections. While neurovascular involvement is common, no pediatric or young adult recommendations for screening exist. We aimed to review our institution's experience with special focus on neurovascular imaging to better understand the pathology and guide screening.

METHODS

A retrospective cohort study of patients with LDS was performed. Demographics, genetic subtype, clinical and radiographical data were analyzed. Primary outcome measures included pathology on neurovascular imaging, time to progression, and arterial tortuosity indexes for bilateral cervical internal carotid arteries (ICA) and vertebral arteries (VA).

RESULTS

Of 47 patients with LDS identified, 39 (83.0%) were found to have neuroimaging. Intracranial and cervical vascular tortuosity were seen in 79.5% and 64.1%, respectively. Twenty-one patients (44.7%) received follow-up screening, of which 3 were found to have progression. Time to progression was an average of 2.1 years. Average follow-up was 607 days (range 123-3070 days). Mean Arterial Tortuosity Index for the right ICA, left ICA, right VA, and left VA were 18, 20, 49, and 47, respectively. Comparison of interval percent change in Arterial Tortuosity Index over the course of follow-up demonstrated small changes in the right ICA (mean 5%), left ICA (mean 1%), right VA (mean 1%), and left VA (mean 2%).

CONCLUSIONS

Arterial tortuosity was most prevalent, though it did not progress significantly over time. We suggest an algorithm for management and serial screening to guide management of pediatric and young adults with LDS.

Association between Extracranial Carotid Artery Tortuosity and Clinical Outcomes in Anterior Circulation Acute Ischemic Stroke without Undergoing Endovascular Treatment

BACKGROUND

Extracranial carotid artery (ECA) tortuosity may influences successful recanalization rates of mechanical thrombectomy in acute ischemic stroke (AIS), yet the relationship between ECA tortuosity and the prognosis of patients with anterior circulation AIS who cannot undergo endovascular treatment remains uncertain. We hypothesized that increased tortuosity of the ECA leads to unfavorable outcomes in such patients.

METHODS

Patients with anterior circulation AIS who underwent computed tomography angiography of the head and neck in our hospital between March 2018 and November 2018 were retrospectively analyzed. The tortuosity of the bilateral ECA was measured, and functional outcomes were evaluated by a modified Rankin Scale (mRS) at 90 days. Multivariate logistic regression models were used to determine the association between ECA tortuosity and outcomes of patients.

RESULTS

A total of 203 patients were enrolled in our study, including 140 patients (68.97%) with favorable outcomes (mRS, 0-2) and 63 patients (31.03%) with unfavorable outcomes (mRS, 3-6). After adjusting for age, atrial fibrillation, stroke territory, and posthospital antithrombotics/statins therapy in multivariate logistic regression model I, ECA tortuosity (odds ratio, 1.052; 95% confidence interval, 1.010-1.096; P = .015) was an independent risk of unfavorable outcomes in enrolled patients. In the other 2 models (II and III) which adjusted for age, sex, baseline National Institutes of Health Stroke Scale score, and with or without posthospital medication, ECA tortuosity was also showed independent relationship to unfavorable outcomes. The optimal cutoff was 12.5 to predict the unfavorable outcomes in a receiver operating characteristic curve.

CONCLUSIONS

Our study demonstrated that the ECA tortuosity is an independent predictor of unfavorable outcomes for anterior circulation AIS patients who without undergoing endovascular treatment after hospital admission. ECA tortuosity values greater than 12.5 may indicate an unfavorable outcome.

Cervicocerebral quantitative arterial tortuosity: a biomarker of arteriopathy in children with intracranial aneurysms

OBJECTIVE

Although intracranial arterial aneurysms (IAAs) of childhood are usually idiopathic, it is possible that underlying arteriopathy escapes detection when using conventional diagnostic tools. Quantitative arterial tortuosity (QAT) has been studied as a biomarker of arteriopathy. The authors analyzed cervicocerebral QAT in children with idiopathic IAAs to assess the possibility of arteriopathy.

METHODS

Cases were identified by text-string searches of imaging reports spanning the period January 1993 through June 2017. QAT of cervicocerebral arterial segments was measured from cross-sectional studies using image-processing software. Other imaging and clinical data were confirmed by retrospective electronic record review. Children with idiopathic IAAs and positive case controls, with congenital arteriopathy differentiated according to aneurysm status (with and without an aneurysm), were compared to each other and to healthy controls without vascular risk factors.

RESULTS

Cervicocerebral QAT was measured in 314 children: 24 with idiopathic IAAs, 163 with congenital arteriopathy (including 14 arteriopathic IAAs), and 127 healthy controls. QAT of all vertebrobasilar segments was larger in children with IAAs (idiopathic and arteriopathic forms) (p < 0.05). In children with congenital arteriopathy without an aneurysm, QAT was decreased for the distal cervical vertebral arteries and increased for the supraspinal vertebral artery relative to healthy children. QAT of specific cervicocerebral segments correlated with IAA size and rupture status.

CONCLUSIONS

Cervicocerebral QAT is a biomarker of arteriopathy in children with IAA, even in the absence of other disease markers. Additional findings suggest a correlation of cervicocerebral QAT with IAA size and rupture status and with the presence of IAA in children with congenital arteriopathy.

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.

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.