Comparison of clinical characteristics and MR angiography appearance in patients with spontaneous intradural vertebral artery dissection with or without subarachnoid hemorrhage

Development and Validation of a Model Based on Circulating Biomarkers for Discriminating Symptomatic Spontaneous Intracranial Artery Dissection

Spontaneous intracranial artery dissection (sIAD) is the leading cause of stroke in young individuals. Identifying high-risk sIAD cases that exhibit symptoms and are likely to progress is crucial for treatment decision-making. This study aimed to develop a model relying on circulating biomarkers to discriminate symptomatic sIADs. The study prospectively collected sIAD tissues and corresponding serums from January 2020 to December 2022 as the discovery cohort. Symptomatic sIADs were defined as those with mass effect, hemorrhagic, or ischemic stroke. A stratification model was developed using the machine-learning algorithm within the derivation cohort (a cross-sectional cohort including from January 2018 to August 2022) and validated within the validation cohort (a longitudinal cohort including from January 2017 to April 2023). In the discovery cohort (n = 10, 5 symptomatic), analyses of tissues and serums revealed 15 proteins and 2 cytokines with significance between symptomatic and asymptomatic sIADs. Among these biomarkers, six proteins and one cytokine, participating in the immune response and inflammatory-related pathways, have a good consistency in expression level between sIAD tissues and serums. In the derivation cohort (n = 181, 77 symptomatic), a model incorporating these 7 biomarkers was highly discriminative of symptomatic sIADs (area under curve [AUC], 0.95). This model performed well in predicting the occurrence of sIAD-related symptoms in the validation cohort (n = 84, 26 symptomatic) with an AUC of 0.88. This study revealed seven circulating biomarkers of symptomatic sIAD and provided a high-accuracy model relying on these circulating biomarkers to identify symptomatic sIADs, which may aid in clinical decision-making for sIADs.

Morphological Features of the Vertebrobasilar System Predict Ischemic Stroke Risk in Spontaneous Vertebral Artery Dissection

The vertebral artery's morphological characteristics are crucial in spontaneous vertebral artery dissection (sVAD). We aimed to investigate morphologic features related to ischemic stroke (IS) and develop a novel prediction model. Out of 126 patients, 93 were finally analyzed. We constructed 3D models and morphological analyses. Patients were randomly classified into training and validation cohorts (3:1 ratio). Variables selected by LASSO - including five morphological features and five clinical characteristics - were used to develop prediction model in the training cohort. The model exhibited a high area under the curve (AUC) of 0.944 (95%CI, 0.862-0.984), with internal validation confirming its consistency (AUC = 0.818, 95%CI, 0.597-0.948). Decision curve analysis (DCA) indicated clinical usefulness. Morphological features significantly contribute to risk stratification in sVAD patients. Our novel developed model, combining interdisciplinary parameters, is clinically useful for predicting IS risk. Further validation and in-depth research into the hemodynamics related to sVAD are necessary.

Morphological characteristics associated with ruptured intracranial vertebral artery dissecting aneurysms

OBJECTIVE

Morphological risk factors for the rupture of intracranial vertebral artery dissecting aneurysms (IVADAs) have not been well characterized. In this study, we aim to identify morphological characteristics associated with IVADA rupture.

METHODS

We conducted a retrospective study of 249 consecutive patients with single IVADAs (31 ruptured and 218 unruptured) admitted to Beijing Tiantan Hospital between January 2016 and December 2020. Various morphological parameters were measured using three-dimensional digital subtraction angiography images. Univariate and multivariate logistic regression analyses were performed to identify morphological characteristics associated with IVADA rupture.

RESULTS

Univariate regression analysis revealed that the coexistence of significant proximal and distal stenosis and posterior inferior cerebellar artery (PICA) involvement were associated with IVADA rupture, while the origin from the dominant vertebral artery was inversely associated with the rupture. Multivariate regression analysis demonstrated that the coexistence of significant proximal and distal stenosis (OR 22.00, 95% CI 5.60 to 86.70, p<0.001) and PICA involvement (OR 4.55, 95% CI 1.36 to 15.20, p=0.014) were independently associated with IVADA rupture.

CONCLUSION

The coexistence of significant proximal and distal stenosis and PICA involvement were independently associated with IVADA rupture. These morphological characteristics may facilitate the assessment of rupture risk in patients with IVADAs.

Arterial stiffness as a risk factor for cerebral aneurysm

OBJECTIVES

A low ankle-brachial index (ABI) is associated with increased mortality and risk of myocardial infarction and stroke in the general population. Arterial stiffness can be assessed non-invasively by the measurement of brachial-ankle pulse wave velocity (PWV), a simple and reproducible method. Because the importance of ABI and baPWV in the pathogenesis of cerebral aneurysms remains uncertain, we aimed to measure ABI and baPWV in patients with intracranial saccular and dissecting aneurysms to clarify whether these aneurysms are associated with arterial stiffness and atherosclerosis.

MATERIALS AND METHODS

We prospectively investigated 78 patients diagnosed with intracranial saccular (n = 66) and dissecting (n = 12) aneurysms. The control group consisted of an age- and gender-matched normal population. We compared the clinical characteristics in patients with intracranial saccular aneurysms and controls, those with intracranial dissecting aneurysms and controls, and those who had cerebral aneurysms with and without subarachnoid hemorrhage. We also compared ABI and baPWV among saccular aneurysm locations and evaluated the correlation between the number of saccular aneurysms and ABI and baPWV.

RESULTS

Multivariate logistic regression analysis shows that hypertension and higher baPWV (>1400 cm/s) are significantly associated with saccular aneurysms. Simple regression analysis revealed no correlation between the number of saccular aneurysms and ABI (r = -0.064, P = 0.611), and baPWV (r = 0.007, P = 0.956).

CONCLUSIONS

The baPWV was associated with intracranial saccular aneurysms even after adjustment of hypertension and smoking. Assessment of the baPWV may aid the evaluation of the intracranial saccular aneurysm and the development of strategies for screening patients with intracranial saccular aneurysms.

Basilar extension and posterior inferior cerebellar artery involvement as risk factors for progression of the unruptured spontaneous intradural vertebral artery dissection

BACKGROUND AND PURPOSE

Spontaneous intradural vertebral artery dissection (siVAD) primarily causes stroke in young and middle-aged individuals; however, data on the relationship between vertebrobasilar morphology and the progression of siVAD are limited.

METHODS

We retrospectively reviewed the data of 77 adult patients who were diagnosed with unruptured siVAD and treated conservatively. We analysed the clinical characteristics, vertebrobasilar morphologies and progression. Progression was defined as siVAD-induced stroke or morphological worsening of the siVAD.

RESULTS

Twenty patients experienced progression. Recurrent ischaemic events that occurred in the vertebrobasilar territory were seen in three patients (3.9%). Two of these three patients and other 17 patients showed morphological worsening. None of the patients presented with subarachnoid haemorrhage. The log-rank test showed male sex, migraine, basilar extension and the posterior inferior cerebellar artery involvement were associated with the progression. Multivariate analysis using the Cox proportional hazards model showed that only basilar extension and the posterior inferior cerebellar artery involvement were significantly related to the progression (p=0.012 and 0.019). In addition, patients with these two vertebrobasilar morphologies had a significantly shorter period of progression of siVAD than those without these morphologies (both, median 242 days; one of two, median 1292 days; none, median 2445 days).

CONCLUSIONS

Thus, some vertebrobasilar morphologies might be markers of the progression of unruptured siVAD. Although all unruptured siVAD patients should be closely monitored, those with basilar extension and posterior inferior cerebellar artery involvement should perhaps be more carefully followed than those without such morphologies.

Pathomorphometry of ruptured intracranial vertebral arterial dissection: adventitial rupture, dilated lesion, intimal tear, and medial defect

OBJECT

Subarachnoid hemorrhage (SAH) due to ruptured intracranial vertebral artery (VA) dissection is a life-threatening disease. Angiographic and symptomatic prognostic factors for rupture and rerupture have been investigated, but the pathological characteristics have not been fully investigated. The authors aimed to investigate these features by performing a pathomorphometic study of ruptured intracranial VA dissections.

METHODS

This study included 50 administrative autopsy cases of fatal SAH due to ruptured intracranial VA dissection among 517 fatal nontraumatic cases of SAH occurring between March 2003 and May 2011. Pathomorphometry was performed using serial 5-μm histological cross-sections with elastica van Gieson staining from each 0.2-mm segment around the ruptured intracranial VA. The longitudinal lengths of 4 types of vascular lesions-adventitial ruptures, dilated lesions where the internal elastic lamina (IEL) was ruptured with adventitial extension, intimal tears where the IEL was ruptured, and medial defects-were calculated based on the numbers of the slides in which these lesions were continuously detected (minimum 2 adjoining slides). The distance from the vertebrobasilar junction to the center of adventitial rupture was also calculated in 37 cases.

RESULTS

All cases showed one adventitial rupture with a mean length of about 1.9±1.1 mm. The center of the adventitial rupture was located 5.0-26.8 mm (mean 14.6±5.5 mm) from the intracranial VA bifurcation. Adventitial ruptures existed in the centers of dilated lesions, where the adventitia was highly extended. Other vascular lesions were serially observed surrounding the adventitial rupture. The mean lengths of dilated lesions, intimal tears, and medial defects were 9.4±4.8 mm, 13.2±6.3 mm, and 15.6±7.2 mm, respectively. The lengths between proximal lesions and distal lesions from the center of the adventitial rupture for both medial defects and intimal tears were significantly longer at proximal lesions than at distal ones (chi-square test, p<0.01).

CONCLUSIONS

Every ruptured intracranial VA dissection has a single point of adventitial rupture where the adventitia was maximally extended, so dilation appears to be a valuable predictive factor for hemorrhagic intracranial VA dissections. The adventitial ruptures were as small as 2 mm in length, and clinically detectable dilated lesions were about 9 mm in length. However, vascular vulnerability caused by IEL ruptures and medial defects existed more widely across a length of VA of 1.3-1.5 cm. Comparatively broader protection of the intracranial VA than the clinically detected area of dissection might be desirable to prevent rebleeding. Broader protection of proximal lesions than distal lesions might be effective from the viewpoint of site distribution of vascular lesions and blood flow alteration to the pseudolumen caused by the dissecting hematoma. Medial defects are the most widely seen lesions among the 4 types of vascular lesions studied. Medial degenerative disease, known as segmental arterial mediolysis, is suspected in the pathogenesis of intracranial VA dissections.