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.

Does ponticulus posticus affect vertebral artery diameter.

PURPOSE: Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery. METHODS: Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement. RESULTS: The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP. CONCLUSIONS: Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients.

Microneurosurgery for Ruptured Aneurysm of Distal Intracranial Vertebral Artery: A Case Report.

The International Subarachnoid Aneurysm Trial led to a shift from clipping to endovascular coiling as the primary therapy for cerebral aneurysm particularly in the management of posterior circulation aneurysm. However, endovascular therapy is often unavailable in low-resource settings, emphasizing the importance of maintaining surgical skill sets in resource-poor countries. This article presents a detailed case report on the successful microneurosurgical management of a 65-year-old female with a history of headache and weakness with past history of hypertension and a right posterior cerebral artery territory infarct who was diagnosed with a ruptured aneurysm situated within the intracranial vertebral artery. Patient was operated with the far lateral approach and clipping of the aneurysm. This case report elucidates the intricate surgical techniques employed, and the challenges neurosurgeons encountered in treating posterior circulation intracranial aneurysms, particularly those with ruptured complications. The aneurysms' intricate anatomy and increased rupture risk necessitate a meticulous microneurosurgical approach. The severity of subarachnoid hemorrhage from ruptured aneurysms increases morbidity and mortality rates.

Selective postmortem arterial angiography of head and neck using digital x-ray or computed tomography: A practical and rapid method to identify vascular injuries.

Identification of vascular injuries is crucial for complete postmortem evaluation and understanding of trauma deaths by the Medical Examiner. Some vascular injuries are difficult to evaluate due to challenging anatomic locations, especially in the head and neck. Documenting injuries of the facial and vertebral arteries is challenging and necessitates time-consuming dissections that can create artifacts and disfigurement. In busy medical examiner offices with a significant number of traumatic injuries, finding a creative solution to employ reliable postmortem angiography is desirable. At the Office of the Chief Medical Examiner for the State of Maryland (OCME), we created and effectively implemented a selective angiography procedure using traditional indwelling Foley catheters and water-soluble barium swallow contrast to evaluate arterial injuries using either digital radiography or computed tomography imaging modalities. This technique and imaging interpretation can be performed by a medical examiner or forensic pathology fellow after basic technical training and basic radiology training. This study outlines the technique, methods, and utilization of the procedure and describes the findings of six deaths due to vascular lesions from different injury mechanisms and disease processes and describes the ease of implementation on a broader scale in busy Medical Examiner's offices.

Soft Tissue Dissection in the Transcondylar Approach: A Modified Layered Technique to Maximize Lateral Access.

Objective While the transcondylar approach is technically challenging, it provides generous ventral and caudal exposure to the craniovertebral junction. This approach requires navigation around multiple eloquent neurovascular structures including the lower cranial nerves, vertebral artery and its branches, and the brainstem. Superficial exposure, including incision location and muscle dissection, can dramatically affect the surgical angle and maneuverability at depth. Methods We demonstrate the transcondylar approach in a step-by-step fashion in a formalin-embalmed, latex-injected cadaver head. Dissection within each layer of the suboccipital muscles was performed. A small cohort with an illustrative case is also included herein. Results The sternocleidomastoid (SCM) muscle was retracted anteriorly; the splenium capitis, semispinalis capitis, and longissimus capitis muscles were disconnected from the superior nuchal line and reflected inferomedially. The suboccipital muscle group was fully exposed. The superior and inferior oblique muscles were disconnected from the transverse process of C1. The superior oblique and the rectus capitis posterior major muscles were then dissected off the inferior nuchal line, and the suboccipital muscle group was retracted inferomedially en bloc . The greater auricular nerve was retracted laterally with the SCM, and the greater occipital nerve was retracted inferomedially with the suboccipital muscle group. Conclusion This technique avoids the obstructive muscle bulk that results from a myocutaneous approach while maximizing deep exposure. Understanding the detailed muscular anatomical relationship with the insertion location and suboccipital nerves is key to complete and safe extracranial dissection. Diligent dissection helps minimize postoperative pain and muscle spasm while optimizing the closure technique.

Exploring vertebral artery stump syndrome: An overlooked cause of posterior ischemic strokes. A narrative review of current management options.

INTRODUCTION: Stump syndrome is defined as a clinical syndrome resulting from a distal intracranial vessel embolic stroke due to an extracranial vessel occlusion. Similar to the anterior circulation, the recurrence of ischemic strokes in territories supplied by the posterior circulation in the presence of vertebral artery occlusion is termed Vertebral Artery Stump Syndrome (VASS). MATERIAL AND METHODS: We conducted a literature review, identifying 72 patients with transient ischemic attacks (TIAs) or ischemic strokes attributed to VASS, according to Kawano criteria. We categorized all patients in two groups focusing on the therapeutic management those who underwent primary medical treatment and those who received endovascular or surgical treatment either in acute or chronic phase. RESULTS: In the anticoagulant therapy group, only 1 patient had a stroke recurrence. Among the 4 on antiplatelets, all had recurrences, but 3 benefited from switching to anticoagulants or endovascular therapy. In the endovascular therapy group, worse outcomes were linked to acute large vessel occlusion. Endovascular treatment of the vertebral artery, in a chronic phase, was explored in literature for recurrent TIAs or minor strokes suggesting that this could be a viable therapeutic alternative when medical treatment failed in preventing recurrence of ischemic stroke. CONCLUSIONS: Some studies suggest that anticoagulant medical therapy may be beneficial for VASS and endovascular therapy has also been reported for selected patients. However, data on treatment outcomes and prognosis are still underreported, making treatment decisions challenging. Randomized Controlled Trials are needed to establish the optimal treatment approach.

A multidimensional pre-operative planning method of unruptured vertebral artery dissecting aneurysms using three-dimensional AWE mapping and hemodynamic simulation.

OBJECTIVE: High-resolution magnetic resonance imaging (HR-MRI) can provide valuable insights into the evaluation of vascular pathological conditions, and 3D digital subtraction angiography (3D-DSA) offers clear visualization of the vascular morphology and hemodynamics. This study aimed to investigate the potential of a multimodal method to treat unruptured vertebral artery dissection aneurysms (u-VADAs) by fusing image data from HR-MRI and 3D-DSA. METHODS: This observational study enrolled 5 patients diagnosed with u-VADAs, who were scheduled for interventional treatment. The image data of HR-MRI and 3D-DSA were merged by geometry software, resulting in a multimodal model. Quantified values of aneurysm wall enhancement (AWE), wall shear stress (WSS), neck velocity, inflow volume, intra-stent flow velocity (ISvelocity), and intra-aneurysmal velocity (IAvelocity) were calculated from the multimodal method. RESULTS: We found the actual lengths of u-VADAs in the multimodal model were longer than the 3D-DSA model. We formulated surgical plannings based on the WSS, IA velocity, and neck velocity. The post-operative value of IAvelocity, neck velocity, and follow-up quantified values of AWE were decreased compared with the pre-operative condition. After that, u-VADAs were complete occlusion in four patients and near-complete occlusion in one patient during the 6th-month follow-up after surgery. CONCLUSION: The multidimensional method combining HR-MRI with 3D-DSA may provide more valuable information for treating VADAs, with the potential to develop effective surgical planning.

Which is a more appropriate recipient for posterior circulation bypass surgery: V3 or V2? Differences in underlying disease and lesion sites between extracranial vertebral artery dissection and atherosclerotic changes. Illustrative cases.

BACKGROUND: Revascularization for extracranial vertebral artery dissection or vertebral artery atherosclerotic occlusive lesions caused by vertebrobasilar insufficiency or posterior circulation infarction is relatively rare. When bypassing the cervical external carotid artery (ECA) or common carotid artery (CCA) using a radial artery (RA) or saphenous vein (SV) graft, it is difficult to determine whether the recipient site should be the V2 or V3 portion. OBSERVATIONS: In case 1, cervical ECA-RA-V3 bypass was performed for bilateral extracranial vertebral artery dissection with the onset of ischemia, and cervical CCA-SV-V3 bypass was added 12 days later. Nine years after surgery, the bilateral vertebral artery dissection had improved, and the patient still had a patent bypass. In case 2, cervical ECA-RA-V2 bypass was performed for arteriosclerotic bilateral extracranial vertebral artery occlusion. The bypass was patent 5 years after surgery. The postoperative course was uneventful in both patients. LESSONS: The authors present cases of posterior fossa revascularization using the vertebral artery V3 and V2 portions via skull base surgery and note that it is important to consider each patient's individual characteristics when selecting the V3 or V2 portion.

Exploring the Nexus: A Systematic Review on the Interplay of the Methylenetetrahydrofolate Reductase (MTHFR) Gene C677T Genotype, Hyperhomocysteinemia, and Spontaneous Cervical/Vertebral Artery Dissection in Young Adults.

Ischemic strokes (IS) in young adults often evade early detection, resulting in delayed diagnosis until complications arise. Cervical/vertebral artery dissection, a significant contributor to these strokes, presents with symptoms such as migraine with aura, severe headache, and neck pain, commonly overlooked due to their nonspecific nature. This review investigates early indicators of artery dissections, emphasizing their importance in diagnosis and exploring the correlation between methylenetetrahydrofolate reductase (MTHFR) gene C677T genotype polymorphism, hyperhomocysteinemia (HHCY), and IS in young adults. This systematic review encompasses a thorough analysis of 11 papers, including four observational studies, three case reports, three narrative reviews, and one experimental study, involving 4,840 patients aged 18-45 years. Findings reveal HHCY as a significant contributor to vascular damage and tissue ischemia leading to IS. The MTHFR gene C677T genotype polymorphism is closely associated with HHCY, often contributing to underdiagnosed strokes in young adults. Cervical/vertebral artery dissection may manifest as initial symptoms of neck pain or headache, remaining undiagnosed until imaging is conducted. Importantly, the review suggests that MTHFR gene polymorphism can be mitigated through simple supplementation with vitamin B12 and folates, serving as a valuable tool for primary prevention. Additionally, betaine, a methyl donor, was explored in severe MTHFR gene polymorphism cases resistant to conventional supplementation. In conclusion, recognizing the significance of early signs and symptoms, along with a high clinical suspicion, is crucial for preventing catastrophic outcomes, mortality, and morbidity associated with IS in young adults lacking traditional risk factors. The MTHFR gene C677T genotype polymorphism, a potential genetic cause, can be easily managed with simple measures but is often overlooked or underdiagnosed.

Cervical Spine Manipulation and Causation of Cervical Artery Dissection: A Review of 10 Case Reports.

Recent media coverage of high-profile cases of cervical artery dissection (CAD) has ignited the discussion about the role of cervical spine manipulation (CSM) in causing cervical artery dissection. However, research does not support a causal association between cervical spine manipulation and cervical artery dissection in a healthy cervical spine. The objective of this study was to review the 10 most recent case reports of cervical spine manipulation and cervical artery dissection for convincing evidence of the causation of cervical artery dissection by cervical spine manipulation. Nine of 10 case reports showed no convincing evidence of a causal relationship between cervical spine manipulation and cervical artery dissection. The 10th case report was exceptional as the CSM was contraindicated by pre-existing cervical spine pathology. We conclude that these 10 case reports provide no convincing evidence of the causation of cervical artery dissection by cervical spine manipulation in a healthy cervical spine. One case report demonstrated that cervical spine manipulation can cause cervical artery dissection when performed in the presence of pre-existing cervical spine pathology. Therefore, we conclude that practitioners should exclude cervical spine pathology before performing cervical spine manipulation.

Lateral atlanto-axial joint access using the C2 pedicle.

BACKGROUND: Neck pain and headaches can arise from the lateral atlanto-axial joint (LAA joint). This pain can be diagnosed with intra-articular injections of local anesthetic. A widely used technique for access to the lateral atlanto-axial joint uses a posterior approach, but this approach can be hazardous because of the proximity of the vertebral artery, the dural sac, and the C2 spinal nerve and dorsal root ganglion. OBJECTIVE: The objective was to describe and test a new technique for accessing the LAA joint that avoids structures that lie behind the joint. INTERVENTIONS: The new technique was described, and tested for tolerance in 10 patients with unilateral suboccipital pain, and tenderness over the LAA joint, along with evidence of LAA joint arthropathy on SPECT CT. The technique requires inserting a needle along a trajectory tangential to the dorsal surface of the C2 lamina. It involves obtaining a declined view of the C2 lamina and C2 pedicle. CONCLUSIONS: In all cases, the C2 pedicle was easily identified and allowed the needle to pass asymptomatically underneath the neurovascular structures behind the joint. The tactile response of the lamina of C2 provided important feedback regarding needle depth caudal to the LAA joint.

Ruptured Vertebral Artery Dissection Treated with Endovascular Intervention.

OBJECTIVE: A retrospective study of cases of endovascular treatment of dissection of the vertebral artery with subarachnoid hemorrhage was conducted. MATERIAL AND METHODS: Data were 11 cases of vertebral artery dissecting aneurysm (VADA) among 291 consecutive subarachnoid hemorrhage patients who underwent clipping or endovascular treatment at Ota Memorial Hospital. Classified into 4 patterns based on the location of the dissection and posterior inferior cerebellar artery (PICA): pre-PICA, post-PICA, involved PICA, and non-PICA. And one of the cases had bilateral vertebral artery dissection, and computational fluid dynamics analysis was included in the study. RESULTS: Ruptured VADA occurred in 11 of the 291 patients (3.8%). Endovascular treatment was performed in 8 of these 11 patients. Postoperative diffusion-weighted imaging detected no high-intensity lesions and no postoperative ischemic complications or rebleeding occurred in any patient. In a case of bilateral VADA, computational fluid dynamics analysis of very low or high wall shear stress at the dissection, low aneurysm formation indicator, and high oscillatory shear index may be considered rupture factors. CONCLUSIONS: Treatment strategies for each branching pattern of PICA can prevent rupture and avoid ischemic complications. And prediction of the rupture side is important in patients with bilateral dissection to consider the appropriate treatment and timing.

Flow alteration surgery using a radial artery graft for recurrent ruptured vertebral artery dissecting aneurysm after stent-assisted coil embolization: A case report.

BACKGROUND: Ruptured vertebral artery dissecting aneurysm (VADA) is often treated surgically with coil embolization and sometimes recurs. We herein report a case of recurrent ruptured VADA after stent-assisted coil embolization (SAC) that was successfully treated with flow alteration surgery using a radial artery (RA) graft. CASE DESCRIPTION: A 67-year-old woman presented with headache and coma. Enhanced CT revealed subarachnoid hemorrhage due to right VADA. Since the left VA was hypoplastic, the aneurysm was treated with SAC. However, follow-up angiography revealed recurrence of the aneurysm. Additional embolization was not considered due to the small size of the recurrent lesion and the presence of a stent; therefore, flow alteration surgery was performed using a RA graft. There were no neurological deficits after surgery or recurrence. CONCLUSION: Flow alteration surgery using a RA graft is useful for recurrent VADA after SAC.

Management and outcomes of cerebrovascular injuries after gunshot wounds to the cervical spine.

STUDY DESIGN: This study was a multicenter retrospective analysis of cervical spine gunshot wound (GSW) patients. OBJECTIVE: The present study was conducted to evaluate the management and outcomes of vascular injuries following GSW involving the cervical spine. SUMMARY OF BACKGROUND DATA: Gunshot wounds (GSW) injuring the cervical spine are associated with high rates of vascular injury. METHODS: Charts of patients with GSW involving the cervical spine at two Level 1 trauma centers were reviewed from 2010 to 2021 for demographics, injury characteristics, management and follow-up. Statistical analysis included T tests and ANOVA for comparisons of continuous variables and chi-square testing for categorical variables, non-parametric tests were used when indicated. Beta-binomial models were used to estimate the probabilities outcomes. Bayesian regression models were utilized to compute risk ratios (RR) and their 95 % confidence intervals (CI) to enhance the inferential robustness. RESULTS: 40 patients with cervical spine GSW and associated cerebrovascular injury were included in our analysis. 15 % of patients had Biffl grade (BG) V injuries, 50 % grade IV, and 35 % grade III-I. Angiography was performed in 35 % of patients. 5 of these patients (BG V-III) required endovascular treatment for pseudoaneurysm obliteration or parent vessel sacrifice. 7 patients (22 %) showed evidence of progression. 70 % of patients were placed on antiplatelet therapy for stroke prevention. Bayesian regression models with a skeptical prior for cerebral ischemia revealed a mean RR of 4.82 (95 % CI 1.02-14.48) in the BG V group, 0.75 (95 % CI 0.13-2.26) in the BG IV group, and 0.61 (95 % CI 0.06-2.01) in the combined BG III-I group. For demise the mean RR was 3.41 (95 % CI 0.58-10.65) in the BG V group and 1.69 (95 % CI 0.29-5.97) in the BG IV group. In the high BG (V, IV) group, 54.55 % of patients treated with antiplatelet therapy had complications. None of the patients that were treated with antiplatelet therapy in the low BG (III-I) group had complications. CONCLUSIONS: Cervical spine GSWs are associated with high-grade vascular injuries and may require early endovascular intervention. Additionally, a high rate of injury progression was seen on follow up imaging, requiring subsequent intervention. Reintervention and demise were common and observed in high BG (V, IV) groups. The incidence of stroke was low, especially in low BG (I-III) groups, suggesting that daily aspirin prophylaxis is adequate for long-term stroke prevention.

Multiple telescopic stenting versus single flow diverter for the treatment of vertebral artery dissecting aneurysm.

Objective: Reconstruction methods, including stent-assisted coiling, multiple telescopic stents, and flow diverters, are preferred modalities for the treatment of unruptured vertebral artery dissecting aneurysms (VADAs). We aimed to compare the clinical outcomes between two reconstructive flow diversion techniques: single flow diverter (FD) device and multiple telescopic stenting (TS). Methods: We retrospectively reviewed the clinical data of 39 patients with unruptured VADAs. Of these, 17 patients were treated with multiple TS and 22 with a single FD device. Aneurysm characteristics and clinical outcomes were compared between the two groups. Results: All aneurysms included in this study successfully achieved flow diversion, regardless of the treatment modality and duration. However, the mean procedure duration to complete the diversion was shorter in the FD group. Subgroup analysis in TS group showed that there were no significant clinical differences between the low-profile visualized intraluminal support and Enterprise stents, except for the mean procedure duration. Conclusions: Both the single FD and multiple TS methods showed excellent angiographic and clinical outcomes in the treatment of unruptured VADAs. However, single FD required a shorter procedure duration and was associated with faster achievement of complete flow diversion.

Traumatic Vertebral Artery Dissection Without Cervical Spine Injury Treated by Mechanical Thrombectomy.

A 59-year-old female injured in a motor vehicle accident presented with progressively impaired consciousness, and emergent magnetic resonance imaging (MRI) revealed basilar artery occlusion (BAO). Mechanical thrombectomy (MT) was performed immediately and achieved complete recanalization. Contrast-enhanced MRI also indicated right vertebral artery dissection (VAD), and the patient was subsequently diagnosed with artery-to-artery embolism caused by traumatic VAD. Anticoagulation therapy was initiated postoperatively, and there was no VAD or BAO recurrence during the three-month follow-up. This is the first reported case of BAO caused by traumatic VAD in an adult without accompanying cervical vertebral fracture treated using MT.

How I do it: Sternocleidomastoid sparing approach for the right vertebral artery to common carotid artery transposition.

BACKGROUND: Direct surgery is an important option to treat vertebral artery (VA) stenosis. METHOD: A patient with symptomatic stenosis at the origin of the right VA underwent transposition of the right VA to the common carotid artery (CCA). Using the sternocleidomastoid sparing approach, the VA was anastomosed to the posterior wall of the CCA by twisting the CCA to expose its posterior wall to face the operative field. CONCLUSION: This approach, consisting of securing the proximal VA and then following it to its distal end, not only preserves the sternocleidomastoid muscle but also protects the sympathetic chains and thoracic duct.

[Craniocervical dissection]. / Dissektionen der hirnversorgenden Gefäße.

CLINICAL ISSUE: Craniocervical dissections are among the most common causes of stroke in people aged under 50 years, which is why it is essential to clarify, diagnose, and treat them as quickly as possible. Dissections usually occur spontaneously due to bleeding into the vessel wall. The affected segments are usually the motion segments of the internal cerebral artery (C1 segment) and the vertebral artery (V3 segment). Clinically, there is head and/or neck pain and neurologic symptoms, which can vary according to the localization of the dissection. PRACTICAL RECOMMENDATIONS: Pathognomonic is the detection of an intramural hematoma due to bleeding into the vessel wall. This can best be detected by magnetic resonance imaging (MRI) in native, fat-saturated T1 sequences (black-blood sequence). In addition, contrast-enhanced angiography should be performed using MRI or, alternatively, computed tomography (CT). As there is an increased risk of embolic or hemodynamically induced strokes, prophylactic treatment should be initiated immediately; it remains a case-by-case decision whether antiplatelet agents or oral anticoagulants are chosen for this purpose.

Evaluation of flow diverter use in acutely ruptured vertebral artery dissecting Aneurysms: A focus on safety and efficacy for rapid Aneurysm obliteration.

OBJECTIVE: Flow diverter device (FDD) has emerged as the reconstruction technique for treating ruptured dissecting vertebral artery Aneurysms (VADA), but data on feasibility regarding re-rupture risk and timing of Aneurysm obliteration following FDD treatment is still limited. Therefore, this study aimed to evaluate the safety and efficacy of FDD in the treatment of VADAs presenting with subarachnoid hemorrhage (SAH). METHODS: We retrospectively reviewed patients with ruptured VADA presenting with subarachnoid hemorrhage who underwent FDD placement at our institution between 2015 and 2023. Patient demographic data, Aneurysm configuration, and occlusion status were analyzed. RESULTS: Thirteen patients with SAH from VADA rupture underwent FDD implantation. The average size of the largest diameter of the Aneurysm was 11.2 mm (range 6.5-21 mm). Eight of 13 (61.5 %) patients had their Aneurysms completely obliterated within 2 weeks after the procedure. The small dissecting Aneurysm (d = 0.636, p = 0.002) and degree of intra-Aneurysmal contrast stasis (d = 0.524, p = 0.026) were associated with rapid Aneurysm occlusion, according to the Somer's d coefficient. There were no ischemic or hemorrhagic complications at the average clinical follow-up of 28.4 months (range 5-67 months) and average angiographic follow-up of 20.1 months (range 3-60 months). A favorable outcome (mRS 0-2) was achieved in 12 patients (92.3 %). CONCLUSIONS: FDD is safe and effective for the reconstruction of acutely ruptured VADAs. In addition, our study emphasizes that small dissecting Aneurysms tend to be rapidly obliterated after flow diversion, which eliminates the risk of re-rupture during the acute phase of subarachnoid hemorrhage.

Behavior of Extracranial-to-Intracranial Extended Arterial Dissections of the Vertebral Artery.

BACKGROUND: Vertebral artery dissections (VADs) may extend from the extracranial to the intracranial vasculature (e+iVAD). We evaluated how the characteristics of e+iVAD differed from those of intracranial VAD (iVAD). METHODS AND RESULTS: From 2002 to 2019, among consecutive patients with cervicocephalic dissection, those with iVAD and e+iVAD were included, and their clinical characteristics were compared. In patients with unruptured dissections, a composite clinical outcome of subsequent ischemic events, subsequent hemorrhagic stroke, or mortality was evaluated. High-resolution magnetic resonance images were analyzed to evaluate intracranial remodeling index. Among 347 patients, 51 (14.7%) had e+iVAD and 296 (85.3%) had iVAD. The hemorrhagic presentation occurred solely in iVAD (0.0% versus 19.3%), whereas e+iVAD exhibited higher ischemic presentation (84.3% versus 27.4%; P<0.001). e+iVAD predominantly presented steno-occlusive morphology (88.2% versus 27.7%) compared with dilatation patterns (11.8% versus 72.3%; P<0.001) of iVAD. The ischemic presentation was significantly associated with e+iVAD (iVAD as a reference; adjusted odds ratio, 3.97 [95% CI, 1.67-9.45]; P=0.002]). Patients with unruptured VAD showed no differences in the rate of composite clinical outcome between the groups (log-rank, P=0.996). e+iVAD had a lower intracranial remodeling index (1.4±0.3 versus 1.6±0.4; P<0.032) and a shorter distance from dural entry to the maximal dissecting segment (6.9±8.4 versus 15.7±7.4; P<0.001). CONCLUSIONS: e+iVAD is associated with lower rates of hemorrhages and higher rates of ischemia than iVAD at the time of admission. This may be explained by a lower intracranial remodeling index and less deep intrusion of the dissecting segment into the intracranial space.