Extracranial Vertebral Artery Research Articles

“Bead to death,” Fibromuscular Dysplasia Presenting as A Rapidly Enlarging Right Anterior Axillary Mass

Fibromuscular dysplasia (FMD) is a rare non-inflammatory, non-atherosclerotic arterial disease characterized by abnormal cellular proliferation and distorted architecture. It commonly affects the renal and extracranial carotid and vertebral arteries, but nearly all arterial beds may be affected, and multivessel involvement is common. We report a rare case of a 31-year-old Filipino female who presented with a rapidly enlarging right anterior axillary mass. Initial consideration was a bleeding soft tissue sarcoma as seen on chest CT scan, while whole abdominal CT scan with IV contrast revealed incidental findings of multiple aneurysms in the superior mesenteric artery, both renal arteries and right common iliac artery, suggestive of fibromuscular dysplasia. Further vascular imaging studies showed a looped left internal carotid, and a tortuous left brachial artery with beading pattern.

Bow–Hunter Syndrome Due to Tandem Lesions; A Case Report

AbstractBow–Hunter syndrome (BHS) includes a form of stroke caused by dynamic factors affecting the extracranial vertebral artery (VA), such as rotation-induced flow disturbance at the atlantoaxial level. BHS is a rare condition that can result from a variety of factors, including abnormal bone compression and vertebral instability. So far, there have been no reports in which both vertebral instability and osteophytes compress the VA at different sites, leading to stroke. Herein, we present a rare case of stroke attributed to BHS involving thrombosis formation due to osteophyte compression at C3/4 and VA occlusion due to vertebral instability at the C4/5 overlapped. A 72-year-old male presented with rotational vertigo and vomiting associated with a cerebellar infarction. Digital subtraction angiography revealed severe stenosis of the left VA with an intra-arterial thrombus. Percutaneous transluminal angioplasty improved the stenosis; however, intravascular ultrasound revealed compression of the VA by osteophytes at C3/4. Additionally, left VA occlusion at C4/5 was confirmed because of vertebral instability. The osteophyte was removed via the anterolateral approach, and the VA was decompressed. The patient's postoperative course was uneventful, with no recurrence for more than 2 years. BHS can occur in the lower cervical spine when vertebral instability coincides with intimal arterial damage caused by osteophytes at other sites.

Treatment of a Rare Case of Giant Vertebral Extracranial Aneurysm

Extracranial vertebral artery (VA) aneurysms are extremely rare and are usually associated with trauma or dissection. Primary extracranial VA aneurysms are far less common. They may be of mycotic origin or associated with systemic diseases such as neurofibromatosis. The presentation and natural history remains idiopathic, and operative management can be often difficult. Angiography remains the gold standard in diagnosis and characterisation of these lesions. We hereby present a case of a primary aneurysm of the extracranial portion of the vertebral artery and its surgical management, which implied an initial endosvacular approach followed by a two-step surgery in order to resect the aneurysm and stabilise the spine.

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.

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. 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. 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.

Extracranial Vertebral Artery Injuries.

Paired vertebral arteries (VAs) travel from the subclavian artery through the cervical spine and into the intracranial space where they contribute to posterior cerebral circulation. Blunt and penetrating injuries to the cervical spine risk injury to the VA. Among the most feared complications of vertebral artery injury (VAI) is posterior circulation stroke. Appropriate screening and treatment of these injuries in the trauma setting remain vitally important to aid in the prevention of devastating neurologic sequelae. A robust knowledge of the VA anatomy is required for spine surgeons to avoid VAI during cervical spine approaches and instrumentation. Both anterior and posterior cervical spine surgeries can place the VA at risk. Careful preoperative assessment with the appropriate advanced imaging studies is necessary to verify the course of the VA in the cervical spine and thus prevent iatrogenic injury because anatomic variations along the course of the artery can prove hazardous if not properly anticipated. Iatrogenic VAI can be treated successfully with tamponade. However, in some cases, ligation, repair, or endovascular procedures may be indicated.

Vertebro-Vertebral Arteriovenous Fistulae: A Case Series of Endovascular Management at a Single Center.

Vertebro-vertebral arteriovenous fistulae (VVFs) are a rare disorder characterized by a direct shunt between the extracranial vertebral artery and the veins of the vertebral venous plexus. This study aims to comprehensively review the characteristics and outcomes of endovascular treatments for VVFs at our center. A retrospective review was conducted on 14 patients diagnosed with a VVF who underwent endovascular treatment at Siriraj Hospital from January 2000 to January 2023. The study assessed patient demographics, presentation, fistula location, treatment strategies, endovascular techniques employed, and treatment outcomes. Among the 14 patients, 11 (78.6%) were female, with an age range from 25 to 79 years (median: 50 years). Spontaneous VVFs were observed in 64.3% of the cases, including three associated with neurofibromatosis type 1 (NF-1). Iatrogenic injury accounted for two cases, and three patients had VVFs resulting from traffic accidents. A pulsatile neck mass and tinnitus, with or without neurological deficits, were common presenting symptoms. Active bleeding was observed in three cases with vascular injury, while unilateral proptosis, congestive heart failure, and incidental findings each presented in one patient. All the VVFs were successfully obliterated without major treatment complications. Parent vessel sacrifice was performed in 85.7% of the cases, while vertebral artery preservation was achieved in the remaining two patients. Embolic materials included detachable balloons, detachable coils, and n-butyl cyanoacrylate (NBCA) glue. All the presenting symptoms showed improvement, and no morbidity or mortality was observed. Endovascular embolization is a feasible and effective approach for achieving complete VVF obliteration with safety. Parent artery sacrifice should not be reluctantly performed, particularly when adequate collateral circulation is demonstrated.

Abstract 85: One-year Outcomes After Endovascular Treatment for Posterior Circulation Tandem Occlusions: A Multicenter Experience of 249 Patients

Introduction: Endovascular thrombectomy (EVT) in posterior circulation tandem occlusions can be challenging and the current evidence is limited to retrospective case series with small sample sizes. Method: Consecutive patients from both PRESIST (ChiCTR2000033211) and BASILAR (ChiCTR1800014759) prospective registries between 2014 and 2022 were included with a total of 53 centers. Posterior circulation tandem occlusion was defined as stroke due to intracranial vertebral (V4), basilar, or posterior cerebral artery (PCA) occlusions, with tandem steno-occlusive lesion >70% of the extracranial vertebral artery and impaired distal flow or partial filling of the VA from collaterals. Outcomes included successful reperfusion defined as modified Thrombolysis in Cerebral Infarction (mTICI) of 2b-3, symptomatic intracerebral hemorrhage (sICH), favorable functional outcome defined as a modified Rankin Scale (mRS) score of 0-3, and mortality, at 90 day and 1-year. Results: After excluding 14 cases with failed access/penetration, a total of 249 patients (mean age of 63.9 years [SD 11.7], 208 [83.5%] male) were included. Basilar artery occlusions were recorded in 179 patients (71.9%) followed by V4 occlusions in 64 patients (25.7%) and PCA occlusions in 6 patients (2.4%). The median baseline NIHSS score was 23 (IQR 12-30) and median PC-ASPECTS was 9 (IQR 7-10). Intravenous thrombolysis was administered in 55 patients (22.1%) while general anesthesia was used in 94/248 patients (37.9%). The median time from onset to puncture time was 320 minutes (IQR 215-496), with a median procedure time of 130 minutes (IQR 89-170). A median number of passes was 1 (IQR 1-2) and successful reperfusion was achieved in 209/249 patients (83.9%). Favorable clinical outcome (90-day mRS 0-3) was achieved in 99/246 patients (40.2%), with mortality affecting 98/246 patients (39.8%). The 24 h post procedural sICH was found in 19/247 patients (7.7%). At 1-year, favorable clinical outcome (mRS 0-3) was achieved in 98/237 patients (41.4%), with mortality affecting 113/236 patients (47.9%). Conclusion: EVT seems to be a safe and effective approach for posterior circulation tandem occlusions. More comparative studies are needed to confirm these results.

The morphology of occlusion stump for endovascular recanalization in non-acute vertebral ostial occlusion

PurposeNon-acute vertebral ostial occlusion (VOO) is a debilitating condition with significant mortality and morbidity rates. However, currently, there is no consensus on the optimal treatment strategy for VOO. This study aims to examine the feasibility, effectiveness, and safety of endovascular recanalization in patients with VOO. MethodsWe conducted a retrospective review of data from 21 consecutive patients with VOO who underwent endovascular recanalization between May 2018 and August 2023. The patients were divided into two groups based on a new angiographic classification proposed by Gao et al. Type I (tapered stump group) included patients with non-acute extracranial vertebral artery ostial occlusion presenting a tapered occlusion stump. Type II (nontapered stump group) consisted of patients with a nontapered occlusion stump. We collected data on recanalization rates, perioperative complications, and follow-up outcomes. ResultsOur analysis included data from a total of 21 patients (22 lesions) with a mean age of 64.6 ± 10.6 years. The technical success rate was 66.7 % (14/21), and the rate of periprocedural complications was 14.3 % (3/21). The success rate of transitioning from the tapered stump group to the nontapered stump group was 90.9 % (10/11) and 40 % (4/10), respectively (P = 0.024). The perioperative complication rate for type I and type II patients was 18.2 % (2/11) and 10 % (1/10), respectively. Among these patients, 18 underwent endovascular recanalization using transfemoral access, while 3 underwent transradial access after failed transfemoral access, with successful outcomes for two patients. ConclusionsThis study suggests that endovascular recanalization may offer a safe, effective, and feasible treatment option for VOO patients. Additionally, the proposed angiographic classification may serve as a useful guide in selecting suitable candidates for surgery.

Analysis of the correlations between the extracranial internal carotid artery and extracranial vertebral artery and mild cognitive impairment.

Vascular tortuosity is a prevalent morphological change that frequently occurs in arteries across different parts of the body. To analyze the relationship between the tortuosities of the extracranial internal carotid artery (EICA) and extracranial vertebral artery (EVA) with mild cognitive impairment. The tortuosity index (TI), vascular deviation degree, tortuosity degree, and angle number of the EICA and EVA were retrospectively analyzed and calculated in 160 patients who underwent computed tomography angiography (CTA) in this study's department, and the Montreal cognitive assessment was adopted to evaluate the cognitive function of the patients. The differences in age, gender, arterial hypertension (AH), and diabetes mellitus (DM) between the normal group and the mild cognitive impairment group were statistically significant (p< 0.01). The TI was negatively correlated with the score of cognitive function. The tortuosities of the EICA and EVA were correlated with mild cognitive impairment (p< 0.05). The reduction in visual-spatial ability was correlated with the right EICA tortuosity, and the reduction in memory was correlated with the EVA tortuosity. Age, gender, HP, DM, and coronary heart disease (CHD) were potential risk factors for carotid tortuosity (p< 0.05). There was a significant correlation observed between the TIs of both the EICA and EVA and the presence of mild cognitive impairment. Advanced age, female, HP, DM, and CHD were independent risk factors for EICA and EVA tortuosities.

Relationship between the Tortuosity of the Extracranial Internal Carotid and Vertebral Arteries on Magnetic Resonance Imaging/Angiography and Vascular Risk Factors in a Japanese Population.

Objective We aimed to investigate the relationship between tortuosity of the extracranial internal carotid artery (ICA) or vertebral artery (VA) and vascular risk factors among residents of Asahikawa, northeast Japan. Methods We retrospectively surveyed participants of "brain dock" medical brain checkups, which involved magnetic resonance imaging and angiography. We measured the tortuosity of the ICA and VA, and evaluated vascular risk factors based on medical interviews, questionnaires, and medical records. Results A total of 218 participants were enrolled in the study. ICA tortuosity (right and left) was significantly correlated with age [odds ratio (OR): 2.452, 95% confidence interval (CI): 1.695-3.548, p<0.001]. A more pronounced correlation was observed in females than in males (OR: 1.678, 95% CI: 1.004-2.807, p=0.048). VA tortuosity (right and left) was significantly correlated with age (OR: 1.786, 95% CI: 1.250-2.550, p=0.001) and smoking history (OR: 2.140, 95% CI: 1.235-3.707, p=0.007), and was more pronounced in females than in males (OR: 1.864, 95% CI: 1.107-3.137, p=0.019). Conclusion ICA tortuosity was correlated with age, while VA tortuosity was correlated with age and smoking history. ICA and VA tortuosity were more pronounced in females than in males.

Cesarean Section in a Patient with Severe Preeclampsia and Vertebral Artery Aneurysm, Secondary to Neurofibromatosis—A Rare Case

Neurofibromatosis (NF1) is a relatively common multi-system genetic disorder. NF1 increases the risk of hypertension, and vasculopathy is a common finding. Extracranial vertebral artery aneurysm, though rare, can rupture and cause fatal hemorrhage. Pregnancy in NF1 is known to be associated with hypertension, preeclampsia, Hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome. We report anesthesia management of a primigravida with 30 weeks of gestation with neurofibromatosis presenting with severe preeclampsia and acute onset vertebral artery aneurysm, who underwent urgent cesarean section. We opted for general anesthesia over regional due to the risk of aneurysm rupture and technical difficulty with vigilant hemodynamic control. Postoperative course was complicated with HELLP and sepsis but was successfully managed. Knowledge, careful preoperative evaluation, appropriate technique, and management of anesthesia, and close postoperative monitoring are of utmost importance.

The Current Status of Endovascular Treatment for Extracranial Vertebral Artery Stenosis in Japan: A Subanalysis of the Japanese Registry of Neuroendovascular Therapy 4.

Endovascular treatment (EVT) is a potential therapeutic option for extracranial vertebral artery (VA) stenosis; however, its efficacy or optimal procedures remain unknown. This study aimed to investigate the recent status of EVT for extracranial VA stenosis in Japan using a nationwide registry. We conducted a post hoc analysis of the Japanese Registry of Neuroendovascular Therapy 4 that enrolled patients who underwent EVT at 166 hospitals in Japan from 2015 to 2019. The outcomes of this study were as follows: procedural success indicating that the planned procedure was completed, modified Rankin Scale (mRS) score at 30 days, and procedure-related complications evaluated according to the procedure during EVT (percutaneous transluminal angioplasty vs. stenting and with or without the use of embolic protection devices [EPDs]). Of 308 eligible patients, 301 (95%) were treated for atherosclerotic stenosis, predominantly by stenting (74%). EPDs were used in 43%, primarily with the distal balloon (63%). The proportion of procedural success was 98%. Functional independence (mRS of 0-2) at 30 days was achieved in 80% of the total cohort, and there were no differences between patients treated with or without stenting or EPDs (74% vs. 82%, p = 0.12, and 80% vs. 80%, p = 0.93). Procedural complications occurred in 28 (9.1%) patients similarly in each group, with distal embolism and vessel dissection being common. In conclusion, EVT is a reasonable option for extracranial VA stenosis as a daily clinical practice. This study emphasizes the potential of EVT in managing extracranial VA stenosis and the need for further research to refine treatment strategies.

WITHDRAWN: A narrative review of techniques for surgical revascularization of the extracranial vertebral artery in vertebrobasilar insufficiency

Vertebrobasilar insufficiency is a condition characterized by poor blood flow through the posterior circulation of the brain, which supplies the brainstem, thalamus, hippocampus, cerebellum, occipital lobes, and medial temporal lobes. Narrowing or occlusion of the vertebral arteries may be result in a range of neurological symptoms, including dizziness, imbalance, dysarthria, and even stroke. If symptomatic patients fail medical management, revascularization of the vertebral artery should be considered. Restoration of blood flow may involve transluminal balloon angioplasty or stent placement; however, certain cases may still require surgical intervention. The complexity of surgical revascularization of the vertebral artery requires careful consideration of skull base and neck anatomy. This review article will focus on bypass of the vertebral artery in the setting of ischemic pathology, describing the technique, anatomical nuances, steps involved in preoperative planning, and postoperative management.

Abstract 286: Endovascular Management of Pediatric Vertebro‐Vertebral Arterio‐Venous Fistula: Case report

Introduction Vertebro‐vertebral arteriovenous fistula (VV‐AVF) is a rare vascular malformation with abnormal high flow shunt between extracranial vertebral artery and an adjacent vertebral vein plexus without intervening capillaries.1 While seen in both adult and pediatric populations, the majority of the VV‐AVFs seen in childhood are largely congenital, seen in the setting of connective tissue diseases such as Ehler‐Danlos Syndrome, Neurofibromatosis type 1, and Marfan’s syndrome, with abnormal involution of the proatlantal system also thought to be implicated.2,3,4 Approximately 70% of the presenting population are symptomatic at presentation, with a pulsatile mass over the side of the neck or pulsatile tinnitus. Additionally, symptoms of vertebrobasilar insufficiency including gait abnormalities, limb weakness, vertigo, recurrent vomiting, diplopia, and in severe cases, cardiac decompensation can also be seen.5 Methods This is a case report of a 2‐year‐old boy presented to our pediatric neurovascular center of excellence with a progressively enlarging pulsatile left neck mass appreciated a year ago. Further evaluation with neck MRA followed by catheter cerebral angiogram revealed an upper cervical AVF with primary arterial feeders from V3 segment of the left vertebral artery, enlarged left occipital artery, and retrograde filling via the right vertebral artery into the left V4 with a direct shunt into a large venous pouch which drained into the vertebral venous plexus. Results Given the progressive enlargement of the mass, location of AVF, and concern for detrimental subsequent venous congestion, decision was made to pursue elective endovascular embolization of the VV‐AVF. The goal was set to obtain complete occlusion of the venous pouch to obliterate all arterial inflow contribution and prevent further recruitment. Occipital artery catheterization was attempted however given the redundant anatomical loops; optimum microcatheter navigation was not feasible. Given the non‐dominant configuration of the left VA, along with the presence of left AICA‐PICA system off the basilar trunk, coil embolization of the venous pouch followed by sacrifice of the V3 segment left VA was achieved satisfactorily leading to obliteration of the AVF along with all the arterial contributions from bilateral vertebral arteries and left occipital artery (Figure‐1). Given the potential vertebrobasilar inadvertent embolization, the procedure was performed under continuous neurophysiological monitoring and post‐periprocedural therapeutic anticoagulation. The patient tolerated the procedure well without any intraoperative issues. He was monitored in the pediatric ICU for 24 hours after the procedure, and subsequently discharged home. Conclusion We report a successful endovascular coil embolization of a VV‐AVF. To our knowledge, this is the youngest reported case where endovascular technique was successfully utilized to achieve cure of such high flow VV‐AVF in this 2‐year‐old patient. Systematic and methodical angiographic analyses with close post‐procedural monitoring are pivotal in ensuring successful outcomes.

Abstract 132: Angioplasty and Stenting for Symptomatic Vertebral Artery Atherosclerotic Disease: A Systematic Review and Meta‐Analysis

Introduction Vertebral artery stenting represents a viable option in treating symptomatic vertebral artery atherosclerotic stenosis. However, its safety and efficacy in improving neurological status and reducing recurrent strokes remain to be established. Methods We systematically searched PubMed, Embase, and Cochrane databases using keywords with Boolean operators to increase search sensitivity and specificity (‘extracranial’; ‘stenting’; ‘vertebral artery’; ‘stenosis’). We included articles reporting patients &gt; 18 years old with symptomatic extracranial vertebral artery stenoses due to atherosclerosis treated with stenting (with or without angioplasty). Those reporting patients with vertebral dissections were excluded. Patients’ characteristics, procedural details, complications, and outcomes were extracted. Estimated rates weighted for sample size were generated for each variable using fixed and random effects models. Results From 89 unique studies identified, 21 met our inclusion criteria and were included in the analysis, comprising 1499 patients with 1570 lesions. The mean age was 65 years, and 74.4% were men. The mean baseline NIHSS was 4.6. The most frequent stenosis location was the V1 segment of the vertebral artery (88.4%). Device‐related issues occurred in 1.8%. Periprocedural ischemic and hemorrhagic complications occurred in 2.1% and 1.7%, respectively. Neurological improvement post‐procedure was observed in 84.2%, and the in‐hospital mortality rate was 2.1%. During follow‐up, in‐stent stenosis &gt;50% was observed in 12.8%, and retreatment with either re‐stenting or angioplasty was performed in 10.8%. Ischemic complications during follow‐up occurred in 5%, and the overall mortality rate was 5%. Conclusion Stenting for the treatment of atherosclerotic vertebral artery stenosis is technically feasible, associated with a high rate of neurological improvement and low short and long‐term complication rates.

Alternative Bypass Technique Using Radial Artery Graft between V3 Segment of Vertebral Artery and Middle Cerebral Artery: Technical Note.

There are some cases where a radial artery (RA) graft is needed for a high-flow extracranial to intracranial (EC-IC) bypass as the external carotid artery (ECA) cannot be utilized as a donor artery. In this report, we describe two cases of extracranial vertebral artery (VA) to middle cerebral artery (MCA) high-flow bypass using an RA graft with an artificial vessel as an alternative bypass technique. The patient was placed supine with a head rotation of 80 degrees. After frontotemporal craniotomy, another C: -shaped skin incision was made at the retroauricular region and the V3 portion of the VA was exposed at the suboccipital triangle. Prior to attempting the high-flow bypass, the superficial temporal artery (STA) was anastomosed to the M4 portion of the MCA as an insurance bypass. The RA graft was anastomosed to the V3 portion of the VA that traveled under the periosteum at the supra-auricular region through an artificial vessel. After RA-M2 anastomosis, an alternative EC-IC bypass, the V3-RA-M2 bypass, was achieved. Postoperative angiography demonstrated successful graft patency and no perioperative complications were observed in both cases. In the cases where a high-flow bypass is required, the V3 portion of the VA is a suitable alternative proximal anastomosis site when the ECA is not a candidate donor. Furthermore, an artificial vessel shows satisfactory protection against graft complications.

Cerebrovascular Fibromuscular Dysplasia - A Practical Review.

Fibromuscular dysplasia (FMD) is a rare idiopathic, segmental, noninflammatory and nonatherosclerotic arteriopathy of medium-sized arteries. It is classically considered to be a disease of young and middle adulthood, with females more commonly affected than males. FMD is a systemic disease. Although historically considered to be rare, cerebrovascular FMD (C-FMD) has now been recognized to be as common as the renovascular counterpart. Extracranial carotid and vertebral arteries are the most commonly involved vascular territories in C-FMD with the clinical presentation determined by vessels affected. Common symptoms include headaches and pulsatile tinnitus, with transient ischemic attacks, ischemic stroke and subarachnoid or intracerebral hemorrhage constituting the more severe clinical manifestations. Cervical artery dissection involving carotids more often than vertebral arteries and intracranial aneurysms account for the cerebrovascular pathologies detected in C-FMD. Our understanding regarding C-FMD has been augmented in the recent past on account of dedicated C-FMD data from North American, European and other international FMD cohorts. In this review article, we provide an updated and comprehensive overview on epidemiology, clinical presentation, etiology, diagnosis and management of C-FMD.

Vascular reconstruction related to the extracranial vertebral artery: the presentation of the concept and the basis for the establishment of the bypass system.

The intracranial vertebrobasilar artery system has a unique hemodynamic pattern (vessel trunk converged bilateral flow with three groups of perforators directly arising from it), is embedded within intense osseous constraints, and is located far from conventional donor vessels. Two major traditional modalities of posterior circulation revascularization encompass the superficial temporal artery to the superior cerebellar artery and the occipital artery to the posteroinferior cerebellar artery anastomosis, which are extracranial-intracranial low-flow bypass with donor arteries belonging to the anterior circulation and mainly supply focal perforators and distal vascular territories. As our understanding of flow hemodynamics has improved, the extracranial vertebral artery-related bypass has further evolved to improve the cerebral revascularization system. In this article, we propose the concept of "vascular reconstruction related to the extracranial vertebral artery" and review the design philosophy of the available innovative modalities in the respective segments. V1 transposition overcomes the issue of high rates of in-stent restenosis and provides a durable complementary alternative to endovascular treatment. V2 bypass serves as an extracranial communication pathway between the anterior and posterior circulation, providing the advantages of high-flow, short interposition grafts, orthograde flow in the vertebrobasilar system, and avoiding complex skull base manipulation. V3 bypass is characterized by profound and simultaneous vascular reconstruction of the posterior circulation, which is achieved by intracranial-intracranial or multiple bypasses in conjunction with skull base techniques. These posterior circulation vessels not only play a pivotal role in the bypass modalities designed for vertebrobasilar lesions but can also be implemented to revascularize the anterior circulation, thereby becoming a systematic methodology.

Association between the degree of vertebrobasilar stenosis, location, infarction pattern, and QMRA flow state.

We aimed to investigate the relationship between the degree and location of vertebrobasilar stenosis and quantitative magnetic resonance angiography (QMRA) distal flow. We retrospectively reviewed patients who presented with acute ischemic stroke with ≥50% stenosis of the extracranial or intracranial vertebral or basilar arteries, and QMRA performed within 1year of stroke. Standardized techniques were used to measure stenosis and to dichotomize vertebrobasilar distal flow status. Patients were grouped based on the involved artery and the severity of disease. All p-values were calculated using chi-squared analysis and Fisher exact test with statistical significance defined as p<.05. Sixty-nine patients met study inclusion, consisting of 31 with low distal flow and 38 with normal distal flow. The presence of severe stenosis or occlusion was 100% sensitive, but only 47% predictive and 26% specific of a low distal flow state. Bilateral vertebral disease was only 55% sensitive but was 71% predictive and 82% specific of a low-flow state and was five times and nearly three times more likely to result in a low-flow state compared to unilateral vertebral disease (14%) and isolated basilar disease (28%), respectively. Severe stenosis of ≥70% may mark the minimal threshold required to cause hemodynamic insufficiency in the posterior circulation, but nearly half of these patients may remain hemodynamically sufficient. Bilateral vertebral stenosis resulted in a fivefold increase in QMRA low distal flow status compared to unilateral vertebral disease. These results may have implications in the design of future treatment trials of intracranial atherosclerotic disease.

Radiological Assessment of Extracranial Vertebral Artery Variations: A Computed Tomography Angiography Study

We evaluated the incidence of intraforaminal and extraforaminal variations of the vertebral artery (VA) in the Omani population using computed tomography angiography (CTA). CTA results of 579 consecutive Omani patients (1158 VAs) were reviewed retrospectively for the analysis of unusual entrance transverse foramen (UE-V2), midline migration (MM), persistent first intersegmental artery (PFIA), and paracondylar process (PP) variations of VA. The anomalous origin and VA dominance were also determined. The sex and side differences in the incidence of these variations were analyzed using the Chi-square test. The incidence of UE-V2 was observed in 10.44% (121 out of 1158) of cases. The incidence of UE-V2 at different vertebral levels was observed in the sequence of C5 (71%) &gt; C4 (20.7%) &gt; C7 (7.43%) &gt; C3 (0.8%). The incidence of MM variation was 1.29%. PFIA and PP variations were found in 0.17% and 0.60% of cases, respectively. Left-dominant VA was identified in 44.7% (259 out of 579) of subjects. The incidence of VA variations was not significantly associated with either sex or side. Anomalous VA origin from arch aorta (3.5%) and right common carotid artery (CCA) (0.08%) was identified. The incidence of UE-V2 in Omani subjects is comparatively higher than that reported in other Asian populations. A rare case of VA originating from the right CCA was also identified.