V3 Segment Research Articles

Abstract WP228: Vertebral Artery Configuration as a Risk Factor for Dissection in Children

Introduction: Arterial ischemic strokes are estimated to occur in 1.2 to 8 per 100,000 children per year with 15-22% occurring in the posterior circulation. Vertebral artery dissection(VAD) is a known cause of posterior circulation ischemic stroke in approx 7% of cases. Pediatric Bow Hunter syndrome, usually presents distinctively with VAD and stroke. It most commonly involves the V3 segment. In 2021, Braga et all proposed a new protocol for management for children with spontaneous VAD.They noted 2 different configurations of the vertebral artery. In this study we go on the explore these different configurations further and their role in spontaneous VAD. Aim & Hypothesis: Two configurations of the vertebral artery at the V3 segment were observed. Type A and Type B depending on the angle of curvature of the V3 segment. Type A config. is more linear with > 110 degree of angulation. Type B config. is angulated with 2 < 110 degree angles. We aim to investigate these configurations in patients without dissection vs those with vertebral artery dissection. We hypothesized that Type B configuration would be more prevalent in patients with spontaneous VAD. Methods: Retrospective chart review conducted at UTSW medical center. MRA/IR angiograms reviewed of 49 patients; 19 with spontaneous VAD and 30 with no vertebral pathology. Results: 79% of the total dissected vessels(19/24) had configuration Type B and 20.83%(5/24) had configuration Type A. In the control group of 30 patients with no VAD, TypeB was present in 25.4%(13/51) and configuration A in 74.5% (38/51). Type B configuration had a statistically significant higher prevalence in V3 dissection group. (p=<0.001) Conclusion: Type B configuration of the V3 segment would warrant further investigation in the right setting.

Surgical treatment of patients with symptomatic Kimmerle's anomaly using video endoscopy

Background: Clinical manifestations of Kimmerle’s anomaly are detected in 5.5 to 20% of patients. The main reason for the development of symptoms is prolonged compression of the V3 (atlantic) segment of the vertebral artery in the bone ring as a result of the atlantooccipital membrane’s exostosis. To date, the final tactics for treating patients with Kimmerle’s anomaly has not been determined. The effectiveness of conservative methods of therapy does not exceed 40%. The aim Of this study was to evaluate the results of a minimally invasive surgical treatment of patients with symptomatic Kimmerle’s anomaly using video endoscopic assistance. Methods: In the period from 2020 to 2022, 15 patients were operated on. The indication for the surgical treatment was the lack of the conservative therapy’s effect for 1 year from the onset of the disease, aggravation of the disease symptoms, a decrease in the blood flow through the vertebral artery at the Kimmerle’s anomaly side when turning the head. The vertebral artery decompression was performed using video endoscopy through a posterior median approach in two (13%) patients and through a paravertebral intermuscular approach (4 cm incision in the occipitocervical region in the projection of the Kimmerle’s anomaly) in thirteen (87%) patients. Results: The outcome of the disease was assessed at the time of discharge from the hospital, as well as in 6 and in 12 months after the operation. Following the surgical treatment, all the patients showed the complete regression of symptoms and restoration of the blood flow velocities in the vertebral artery. There were no complications after the operation. The use of video endoscopy made it possible to reduce the size of the surgical wound from 12 cm to 4 cm, which contributed to a decrease in the intensity of pain in the postoperative period, early activation and a decrease in the duration of the inpatient treatment. Conclusion: With the proper selection of patients with Kimmerle’s anomaly, decompression of the V3 segment of the VA using video endoscopy is a safe and effective method of treatment.

Traumatic injury of vertebral artery complicated by formation of a giant pseudoaneurysm of the V3 segment (clinical observation and literature review)

Traumatic vertebral artery injury (TVAI) is a rare but severe pathology which can be associated both with penetrating injury of the neck and blunt or unclassified injury. Injury of the vertebral artery, especially due to gunshot or knife wounds, causes severe condition of the patients, development of a wide spectrum of complications including life-threatening, high rates of disabilities and mortality.There is no consensus on the treatment tactics for this pathology. Open surgery as the first stage of surgical intervention can be used in a limited number of cases. X-ray endovascular techniques of TVAI treatment are considered to be preferable.We present a clinical case of a 27‑year-old patient with TVAI caused by a penetrating gunshot wound of the neck and complicated by formation of a giant pseudoaneurysm of the V3 segment of the vertebral artery. Two-stage combination treatment of TVAI was performed using endovascular and open surgical techniques.Descriptions of TVAI cases are rare, and further accumulation and analysis of corresponding data and proposals on treatment of the patients with TVAI will help to formulate precise algorithms of doctors’ actions and optimize treatment tactics.

Cluster of variations involving vertebral, renal, and obturator arteries in a single human body- A cadaveric case report

We describe a unique triad of arterial variations that include vertebral, renal, and obturator arteries in a single cadaver. A combination of arterial variations was observed in a 60-year male; formalin embalmed cadaver during the routine dissection while teaching undergraduate students. The origin, course, branching pattern, and termination of the vertebral, renal, and obturator arterial systems were noted, along with the vessels' diameter close to their origin. The following variations were observed: a) Hypoplastic V4 segment of the right vertebral artery; Right Posterior Inferior Cerebellar artery had a relatively proximal origin from the V4 segment of vertebral artery and coursed in an inverted ‘U’ shaped manner cranially, which resembled duplicated V4 segment of the right vertebral artery, b) Right accessory renal artery originated from abdominal aorta distal to the right renal artery and the right gonadal artery originated from the right accessory renal artery, c) Right obturator artery originated from the posterior division of the right internal iliac artery, and the left obturator artery originated from the trunk of the left external iliac artery. Such a combination of variations in the anatomy of vertebral, renal, and obturator arteries was not reported previously. This case report will interest neurosurgeons and radiologists because of the possibility of concomitant arterial variations.

New evidence for fractional pressure ratio prediction by pulsatility index from transcranial Doppler in patients with symptomatic cerebrovascular stenosis disease.

The pulsatility index (PI) derived from transcranial Doppler (TCD) assessment may represent the cerebral resistance and altered cerebral blood flow. The purpose of this study was to assess the performance of the TCD PI in correlation with wire-based fractional pressure ratio (FPR). This study included 33 patients with symptomatic atherosclerotic lesions of the extracranial and intracranial large arteries, specifically the internal carotid artery, middle cerebral artery (MCA), vertebral artery (VA) V4 segment, and basilar artery (BA), all of which exhibited luminal stenosis ranging from 50% to 70%. TCD was performed prior to angiography in order to determine the flow distal to the lesion. We performed cerebrovascular angiography with a pressure wire to measure the FPR of vessels with stenotic lesions. Bland-Altman analysis and ordinal least square (OLS) linear regression were used to quantify the correlation between PI and FPR. A total of 42 TCD data points were analyzed. At the TCD locations distal to the lesions, the correlation coefficients were no less than 0.90%, with almost all P values <0.001, which indicated very strong positive correlations; the exception to this was the distal TCD for MCA segment lesions (r=0.897; P=0.015) and VA V4 segment (r=0.964; P=0.036). The Bland-Altman plot demonstrated a small difference (0.003) between the distal TCD PI and the FPR, with an acceptable 95% confidence interval [95% confidence interval (CI): 0.06-0.12]. The PI obtained through TCD assessment distal to the stenotic lesion exhibited a correlation with the FPR computed using pressure wire measurements.

МИКРОХИРУРГИЧЕСКОЕ ЛЕЧЕНИЕ ДИСТАЛЬНОЙ АНЕВРИЗМЫ ЗАДНЕЙ НИЖНЕЙ МОЗЖЕЧКОВОЙ АРТЕРИИ В ХОЛОДНОМ ПЕРИОДЕ КРОВОИЗЛИЯНИЯ (КЛИНИЧЕСКИЙ СЛУЧАЙ)

Aneurysms located on the distal portion of the posterior inferior cerebellar artery (PICA) are a rare disease that requires special treatment. Keeping the artery patent while excluding the aneurysm from the blood flow is essential during surgery. The patency ensures adequate blood circulation in the surrounding tissues and reduces the risk of ischemic complications. Therefore, carefully manipulating nearby anatomical structures is crucial to ensure successful surgery, minimize complications, and achieve optimal treatment results. This article describes a case of successful surgical intervention in a patient with a complex distal PICA aneurysm. The surgery was performed in the area of the anterior medullary segment using an extended retrosigmoid retrocondylar approach combined with C1 hemilaminectomy and monitoring the V3 segment of the vertebral artery. This approach has proven safe and effective, representing a promising alternative for the microsurgical treatment of PICA aneurysms, both in the acute and subacute stages of hemorrhage. The chosen surgical tactics helped prevent recurrent subarachnoid and intraventricular bleeding, as well as minimize the risk of ischemia, edema, and compression of the brain stem. These complications could lead to severe disability or even death. Keywords: Posterior inferior cerebellar artery, distal aneurysm, intraventricular hemorrhage, microsurgical treatment, aneurysm clipping, clinical case.

New Microsurgical Techniques for Refractory Vertebrobasilar Insufficiency Addressing V1 Segment of Vertebral Artery’s External Compressions and Dolichoarteriopathies

New Microsurgical Techniques for Refractory Vertebrobasilar Insufficiency Addressing V1 Segment of Vertebral Artery’s External Compressions and Dolichoarteriopathies

Vertebrobasilar Insufficiency Syndrome in Extension: Insights into Surgical Treatment

Rotational vertebrobasilar artery syndrome, or bow hunter syndrome, is a rare yet well-documented pathology. This study presents a surgical approach to a latent manifestation of dynamic, extension-only, bilateral codominant vertebral artery compression in the V3 segment, associated with craniocervical instability and central canal stenosis. The clinical presentation involves the treatment of positional vertigo resulting from left and high-grade right vertebral artery stenosis during neck extension only. Diagnosis was confirmed through a formal angiogram under provocative maneuvers. Surgical intervention, detailed in this section, employed a multidisciplinary approach, including intraoperative angiograms to ensure patent vertebral arteries precraniocervical fusion. The surgical treatment demonstrated success in addressing extension-only vertebrobasilar syndrome and associated complications of C1-2 pannus and craniocervical instability. Intraoperative angiograms confirmed vertebral artery patency pre- and postsurgical positioning, ensuring the effectiveness of the multidisciplinary approach. This study concludes by highlighting the successful multidisciplinary surgical treatment of a patient with nonunion of a C1 Jefferson fracture, leading to extension-only vertebrobasilar syndrome complicated by C1-2 pannus and craniocervical instability. The importance of considering vertebral artery dynamic stenosis in cases of positional vertigo or transient neurological symptoms following an injury is emphasized. Surgical stabilization, particularly when conservative measures prove ineffective, is recommended, with careful attention to pre- and postsurgical positioning to verify vertebral artery patency and posterior vasculature integrity.

Flow Diversion for the Treatment of Posterior Inferior Cerebellar Aneurysms: A Novel Classification of Posterior Inferior Cerebellar Artery Origin.

Flow diversion (FD) for posterior circulation aneurysms, such as proximal posterior inferior cerebellar artery (PICA) aneurysms, remains "off-label" and controversial. Although there are reports of using FD in the vertebral artery (VA) to treat PICA aneurysms, the differences between structural PICA-origin variants have not been explored. We analyzed PICA aneurysms treated with FD, assessed radiographic and clinical outcomes, and presented a novel classification of the PICA origin in relationship to aneurysm anatomy. We performed a retrospective study of prospective data for intracranial aneurysms treated with FD at a major academic institution from 2013 to 2022. Proximal PICA aneurysms that underwent FD placement in the V4 segment of the vertebral artery were included for analysis. A literature review was performed on PubMed to evaluate previously published cases. The PICA origin was characterized by 4 distinct subtypes. Type 1 describes the PICA originating adjacent/separate to the aneurysm neck, Type 2 with the PICA originating from the aneurysm neck, Type 3 with the PICA originating from the aneurysm dome, and Type 4 (True PICA aneurysm) with the aneurysm located proximally on PICA, distal to the PICA-VA junction. Thirteen proximal PICA aneurysms were identified and included in the analysis. Patients were primarily female (76.9%), with a median age of 62 years. The aneurysm median maximum diameter was 5.8 mm. From the total sample (institutional and literature review cases), type 1 had a 100% complete and near-complete occlusion rate, type 2 had 75.0%, type 3 had 88.9%, and type 4 had 75%. The overall complete and near-complete occlusion rate was 83.3% (20/24). FD in the V4 VA segment is an effective way to treat proximal PICA aneurysms. Exploring the relationship between PICA origin is a helpful method in predicting occlusion rates for proximal PICA aneurysms and may lead to improved treatment considerations.

Abstract 14002: Endovascular Embolization and Coiling for an Intracranial Aneurysm in a 9 - Month Old Infant With Kawasaki Disease- A Unique Case Report

Introduction: Cerebrovascular involvement is rare in Kawasaki disease.We present a unique case of such an infant who developed intraventricular haemorrhage and was diagnosed with an intracranial aneurysm. Case Report: A 9-month-old female infant was referred to us with 5 days of high-grade intermittent fever &amp; watery diarrhoea that did not respond to routine care. On arrival, she was stable with WBC count 20,000/UL, CRP 111 mg/L &amp; ESR 85 mm/hr.She continued to have fever spikes and Echocardiography revealed dilated left coronaries with a LAD Z score of +2.92. Hence, by pediatric guidelines, she was started on IVIg (2g/kg) for Kawasaki disease. Repeat echocardiography 2 days later showed reduction in coronary prominence. On Day 10, the child developed episodes of abnormal posturing and respiratory failure. MRI brain showed intraventricular haemorrhage in dependent horns of bilateral lateral, 3rd and 4th ventricles and subarachnoid haemorrhage. CT angiography showed a saccular aneurysm at the junction of V4 segment of right vertebral artery &amp; basilar artery (Figure 1). She underwent endovascular embolization, coiling of aneurysm&amp; omaya reservoir insertion(Figure 2). She was weaned off supportive care &amp; recovered well. Conclusion: Unlike fe existing reports, haemorrhage occurred during active phase of the disease and not years after diagnosis. To our knowledge, this is the first report of endovascular management of aneurysmal subarachnoid haemorrhage in KD in an infant. This uncommon presentation in an infant warrants discussion on whether routine screening of all children suspected of Kawasaki disease for extracardiac aneurysms might be potentially life-saving.

Abstract 159: Computed Tomography Angiography Negative Spinal Artery Dissection

Introduction Vertebral artery dissection (VAD) is a relatively common cause of ischemic stroke, especially after chiropractic neck manipulation. VAD usually can be diagnosed by noninvasive imaging studies such as CT angiography (CTA) of the head and neck with suggestive findings of an arterial string sign, arterial stenosis, a double lumen sign, a pseudoaneurysm, or an occlusion. However, in rare situations, CTA may display normal arterial caliber except for very subtle signs such as abnormal dorsal thickening of the arterial wall against adjacent fat at the V3 segment of the vertebral artery. This is referred to as the "suboccipital rind sign." Here we wish to report such a case as identified at our institution. Methods Electronic charts of a patient with acute spinal shock and strokes were reviewed. Results The patient is a 36‐year‐old female with chronic neck pain, status‐post C5‐T1 spinal fusion who presented emergently with quadriparesis that following chiropractic neck manipulation. She felt a “pop” at the neck during the neck manipulation. She shortly thereafter began experiencing persistent neck pain associated with tingling sensations of both upper extremities on her drive home. She then noted transient right‐hand weakness as she was attempting to open a package. Her symptoms then temporarily resolved with rest, but after some time the paresthesia and neck pain reoccurred, worsened, and quickly progressed to quadriplegia. Brain MRI was negative for acute stroke. However, MRI of the cervical spine demonstrated acute cervical spinal cord ischemia in addition to post‐surgical changes. CTA head and neck reported normal arterial caliber. A diagnostic angiogram was performed that showed no evidence of arterial dissection but did demonstrate absence of the anterior spinal artery. Subsequently, CTA was further reviewed on thin slice revealing a “suboccipital rind sign" of the left V3 segment, suggesting left vertebral artery V3 segment dissection. Hypercoagulable workup was negative, and the patient was treated with anticoagulation. Conclusion Arterial dissection is usually readily diagnosable by CTA with high sensitivity. However, a study with normal caliber vessels in the reconstituted images does not always exclude an arterial dissection. To our knowledge there have been six reported vertebral dissection cases with a normal appearing lumen on CTA or conventional angiography. However, similar to our case, they displayed “suboccipital rind” signs on CTA thin cross‐section due to the thickening of the dissected artery on the V3 segment. The V3 segment has a horizontal course which runs parallel to the axially acquired imaging plane, which makes it difficult to appreciate the classic crescentic wall hematoma associated with arterial dissection. We hope that increased awareness of the typical location and appearance of the “suboccipital rind” sign on CTA may increase the detection rates of subtle arterial dissections in the setting normal‐appearing arterial lumens.

Abstract 089: A Case of Complicated Dissection: Vertebral Artery Sacrifice for Recurrent Stroke Prevention

Introduction Posterior circulation strokes account for 20% of ischemic strokes (1). Optimal management for posterior circulation strokes has been studied less than for anterior circulation strokes (2). Endovascular parent vessel sacrifice is an established technique used to treat vascular pathologies. There is limited evidence for parent artery sacrifice for recurrent strokes and there is no current guideline for standard of care. Methods '‐ Results 51‐year‐old gentleman with history of tobacco use presented with left homonymous hemianopsia, onset 1.5 hours prior to arrival. CT brain showed no bleed and patient received IV tissue‐plasminogen activator (tPA). CT angiography (CTA) demonstrated occlusion of the right posterior cerebral artery (PCA) and dissection of the left vertebral artery (V2 segment) with distal reconstitution. He underwent emergent thrombectomy for right P2 thrombus with complete reperfusion TICI 3 (Thrombolysis in Cerebral Infarction Score). Less than 24 hours later, he developed a right homonymous hemianopsia, and was found to have a new occlusion of the left P1 segment of the left PCA. Emergent thrombectomy was performed with complete reperfusion (TICI3). MRI brain demonstrated bilateral PCA territory infarcts. Within 12 hours of the second thrombectomy, his neurological exam deteriorated, and interval imaging revealed a basilar trunk thrombus, for which he underwent a successful endovascular thrombectomy complete reperfusion (TICI3). His antiplatelet regimen was optimized with Aspirin. Heparin was considered as treatment but was not provided because of the hemorrhagic conversion of his ischemic strokes. Given the persistent recurrence of thromboemboli in the posterior circulation despite being on optimal medical management, and evidence of hemorrhagic conversion, a decision was made to perform endovascular coil embolization of the left vertebral artery V2 segment at the site of dissection. Angiographic imaging demonstrated antegrade blood flow through the dissection as the source of recurrent embolic strokes. Six Stryker Target coils were deployed spanning the region of dissection within the left V2 segment via a right radial access with the guide catheter in the right vertebral artery. Post coil embolization angiographic runs demonstrated complete occlusion of the left vertebral V2 segment at the region of dissection which was confirmed via a left vertebral injection from a left femoral arterial access. There was preservation of ascending cervical collaterals beyond the dissection with patency of the contralateral vertebral artery supplying the intracranial circulation. Following embolization, repeat imaging showed no new infarcts and no new or worsening hemorrhage. He was continued on Aspirin monotherapy. It is notable that though his neurological exam deteriorated during each recurrent thromboembolic event, his neurologic exam at the time of discharge significantly improved with NIHSS of 3. He is currently being followed at our neuroscience institute. Conclusion Cervical arterial dissections pose increased risk for ischemic strokes (3). Vertebral artery dissection accounts for approximately 2%, of which, 10‐25% occur in middle‐aged and younger patients (4). This is a case of a young patient that exemplifies a successful role for vertebral artery sacrifice with coil embolization to prevent recurrent thromboembolic posterior circulation strokes. However controlled studies are needed for safety and efficacy of these interventions.

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 164: Chronic Total Occlusion of the Bilateral Internal Carotid Arteries, Vertebral Arteries and Basilar Artery

Introduction Bilateral internal carotid arteries (ICAs), vertebral arteries (VAs), and basilar artery chronic total occlusion is an exceedingly rare condition. Possible underlying etiologies include atherosclerosis, Moyamoya disease, dissection, among others. Methods Here we describe a 58‐year‐old man with chronic total occlusion of the bilateral ICAs, VAs and basilar artery of unknown etiology. Results A 58‐year‐old man who is independent for ADLs/iADLs with a history of prior ischemic strokes (first stroke at 40 years old) with residual left‐sided weakness and dysarthria, hypertension, hyperlipidemia, prior blood clots (previously on warfarin), post‐stroke epilepsy, and never smoker presented as a code stroke to the emergency department after waking that morning with worsening of his residual left‐sided weakness and dysarthria. On arrival, blood pressure was 165/94 mmHg and blood glucose was 108 mg/dL. His NIHSS was 6. His neurologic exam was grossly similar to that documented 19 months ago. In the CT scanner, he developed tonic‐clonic movements of the left arm and leg, confusion, and emesis. Later, he stated he had missed several doses of his prescribed levetiracetam. Head CT and brain MRI revealed encephalomalacia in the brainstem and bilateral cerebellar and cerebral hemispheres. Brain MRI did not demonstrate any diffusion restriction changes. CTA showed chronic occlusion of both ICAs (proximal, distal, and terminus), M1s, VAs (V4 segment), and basilar artery. CTA also revealed that the brain parenchyma was being perfused by collaterals between the external carotid artery (ECA) branches, superficial temporal artery, and M2 branches bilaterally and the bilateral posterior circulation arteries were small and reformed through collaterals. CTP showed a core and penumbra volumes of 0 mL. His presentation was consistent with a seizure. He was admitted to the stroke service for work‐up of his abnormal brain vasculature. Catheter angiography confirmed the CTA results demonstrating occluded bilateral cervical and intracranial segments of the ICAs, collaterals from bilateral ECA branches supplying the intracranial circulation, right VA occlusion distal to the right PICA, and left VA occlusion distal to the V3 segment. Remaining work‐up including A1c, LDL, urine drug screen, EKG, transthoracic echocardiogram, and telemetry was unrevealing other than for an LDL of 152. Routine EEG showed moderate generalized showing. During hospitalization, his home amlodipine and losartan medications were discontinued with the goal of maintaining a blood pressure target of 140‐160 systolic indefinitely, to minimize the risk of hypoperfusion cerebrally. Give his robust collaterals, surgical treatment with revascularization was not pursued. His home aspirin and rosuvastatin 40 mg daily were continued and ezetimibe 10 mg daily was added. His home levetiracetam was increased from 500 to 750 mg twice daily given recent unprovoked seizures at home. He was discharged to an inpatient rehabilitation facility. Conclusion To our knowledge, this is the first case report to show chronic total occlusion of the bilateral ICAs, VAs, and basilar artery. Diagnosis of Moyamoya disease stage VI ("disappearance of the Moyamoya") was entertained but felt to be less likely given involvement of the proximal ICAs and posterior circulation. Other diagnostic consideration included atherosclerosis. Overall, the underlying etiology of his condition remained elusive.

Abstract 114: “Failing” DAPT? Think Again

Introduction Bow Hunter’s Syndrome (BHS) is a rare etiology of vertebrobasilar insufficiency that usually occurs with head turn, which causes compression of the vertebral artery by an osteophyte. There is subsequent hypoperfusion of brain tissue, but thromboembolism and ischemic stroke is rare. Timely diagnosis is imperative, as decompressive surgery can be curative. This unique case highlights the diagnostic and therapeutic challenges of a patient with multiple vascular risk factors who suffered from strokes secondary to BHS. Methods A 79‐year‐old man with a past medical history of peripheral artery disease, abdominal aortic aneurysm, myocardial infarction with drug eluding stents (on dual antiplatelet therapy (DAPT)), complete heart block with pacemaker, heart failure with reduced ejection fraction, hypertension, hyperlipidemia, and diabetes mellitus presented to an outside hospital with recurrent episodes of right‐sided weakness every 1‐2 days over the previous 3 weeks. Episodes always occurred after activity and only upon sitting. He had previously undergone non‐contrasted head computed tomography (NCHCT) (magnetic resonance imaging (MRI) was unable to be performed secondary to pacemaker), which did not reveal strokes. His initial computed tomography angiogram (CTA) of the head and neck was unremarkable. However, CTA head and neck 4 days later demonstrated 90 percent stenosis of the mid left V2 at the C3‐4 level and a 75‐90 percent stenosis of the left mid V2 segment at the C5‐6 level (hard and soft plaque in these areas). He was switched from DAPT to aspirin and warfarin because he was considered a “DAPT failure.” He continued to have episodes, so he was transferred to our institution for a second opinion. Results On arrival, the exam was notable for right‐sided hemiparesis and dysmetria. Repeat CTA head and neck demonstrated multifocal intracranial atherosclerosis with marked stenosis of the left V4 segment. However, marked stenosis at V2 appeared to be owed to external compression from facet arthrosis rather than atherosclerosis. He also had moderate stenosis of the right V4 segment. Eventually, he underwent an MRI brain, which demonstrated acute to subacute infarcts in the left pons. He was taken for a cerebral angiogram on the same day, which demonstrated stenosis of the distal V2 segment of the left vertebral artery (at the level of C3‐C4) with interval development of marked stenosis following neck flexion and occlusion of the left vertebral artery following leftward head rotation. Findings were most consistent with rotational occlusion of the left vertebral artery, which is also known as BHS. The patient underwent surgery, but suffered from a gastrointestinal bleed and developed post‐operative atrial fibrillation; after a risks/benefits discussion, he was discharged on anticoagulation only. He had no further strokes. Conclusion This patient suffered from ischemic strokes, which occur in less than 10% of BHS cases. Contralateral vertebral artery stenosis, which is unable to supply retrograde flow during compression, is the likely etiology of this patient's strokes. Recurrent posterior circulation strokes in the setting of optimal medical management should clue clinicians to consider other etiologies of stroke. Dynamic angiography is the gold standard for BHS and decompressive surgery is often curative.

Abstract 123: First Off‐Label Use of the XIENCE Skypoint Stent for Mechanical Thrombectomy Rescue

Introduction Despite technical advances in mechanical thrombectomy (MT), failure to achieve recanalization in the posterior circulation remains a significant challenge. Rescue strategies to increase MT success in the posterior circulation have been explored. We demonstrate the first successful off‐label use of XIENCE Skypoint™ (Abbott), a balloon‐mounted drug‐eluting stent (DES), for intracranial MT rescue in the posterior circulation. Methods Case report and endovascular technique. Results A 52‐year‐old man with hypertension, hyperlipidemia, and deep venous thrombosis who presented with acute ischemic stroke in bilateral occipital, lateral pons, and cerebellar regions. Computed tomography angiography (CTA) showed bilateral vertebral artery occlusion consistent with a history of dissection in the setting of cervical manipulation. Admission National Institutes of Health Stroke Scale (NIHSS) 20. Last known well less than 12 hours from presentation. Intravenous thrombolysis was deferred as the patient was on pre‐admission anticoagulants. Mechanical thrombectomy failed after several unsuccessful passes (Fig 1). XIENCE Skypoint™ stent was deployed within the left vertebral artery (V4 segment) with restoration of flow preceded by eptifibatide drip (Fig 2). Repeat CTA at six months showed patent left vertebral and basilar arteries. Conclusion Rescue stenting using DES may be a successful and safe therapeutic intervention for challenging failed MT. The off‐label use of DES for intracranial pathologies continues to expand. This is the first case report in the literature describing successful rescue stenting using XIENCE Skypoint™ in the posterior circulation. Further investigation is warranted to fully elucidate the risks and benefits of this treatment approach.

Abstract 094: Sudden Onset Dysphagia: A Symptom To Be Aware of During Code Strokes

Introduction Lateral medullary infarction (LMI) can present with dysphagia, dysphonia, dysarthria, vertigo, nausea, skew deviation, and ipsipulsion. Patients may also exhibit sensory loss and ipsilateral Horner’s syndrome. LMS often develops because of an acute infarct from the vertebral arteries or posterior inferior cerebellar arteries (PICA). The most common mechanism of stroke usually is atherothrombosis, followed by cardioembolic, dissection and embolic source of undetermined source (ESUS). While dysphagia often accompanies the constellation of LMS symptoms, it is rarely the first symptom and has only been reported in a few cases in the literature. In this report we describe the case of a man in his 40s with acute onset dysphagia as the presenting finding ahead of an LMS diagnosis. Methods The patient was identified in routine clinical practice. Results A man in his 40s with medical history of HTN, type 2 DM and polycystic kidney disease, presented with sudden‐onset dysphagia which started while he was drinking alcohol. Later he noticed that he was unable to keep his balance. His National Health Institute Stroke Scale was 4. Neurologic exam was pertinent for left‐sided miosis, ptosis, and dysmetria. Pinprick and temperature sensation were decreased on the right arm and leg. Facial sensation to light touch was diminished on the left. Brain MRI showed an acute infarct in the left lateral medulla (Figure A). CTA showed calcified atherosclerosis of the V4 segment of left vertebral artery (Figure B). Mechanism of ischemic stroke was artery to artery thromboembolism from the left V4 segment of vertebral artery. For secondary prevention, dual antiplatelet therapy, high intensity statin, and optimization of his risk factors were initiated. Conclusion This case report demonstrates that dysphagia can be the initial symptom of an acute ischemic stroke. Diagnosis and recognition of an atypical presentation of lateral medullary syndrome can pose a particular challenge especially in this era of “time is brain” but is of the utmost importance to facilitate good outcomes. Patients presenting with dysphagia who have risk factors for stroke and no other obvious etiology for their symptoms should be worked up for possible cerebrovascular etiology.

Abstract 124: Vertebral Artery Web as a Rare Cause of Ischemic Stroke in a young male

Introduction Vertebral artery web has been rarely identified compared to the frequently reported, carotid artery web as etiology of ischemic stroke. Here we present a young patient with symptomatic vertebral artery web. Methods Case Report Results 35‐year‐old male presented with persistent, intermittent, bilateral visual scintillations lasting 30‐60 seconds for one month. Neurological examination positive for bi nasal superior quadrantanopia. Computed tomography (CT) of head showed patchy hypo density in right posterior circulation artery (PCA) territory. Magnetic resonance imaging (MRI) showed restriction diffusion over bilateral PCA territories right greater than left (image A). MR Angiogram head and neck showed abnormal contour within right vertebral artery in V2 segment compatible with dissection (image B). Patient’s hypercoaguable, inflammatory and rheumatological markers were unremarkable. The patient was started on aspirin 81 mg daily and Plavix 75 mg daily for three weeks followed by aspirin monotherapy. Repeat CT angiogram 11 months later still showed right V1/V2 junction irregularity (image C). DSA performed one month later revealed right cervical vertebral artery web with mild stagnation of blood flow (image D). Patient had no recurrence of symptoms and was continued on aspirin. Conclusion Ischemic stroke is rare in young adults. According to recent studies, prevalence of stroke in young adults’ ranges from 10‐15% of entire population stroke burden. Our case describes a young patient with posterior circulation stroke caused by a vertebral artery web which was confirmed with DSA. Vertebral artery web has limited scientific documentation throughout the literature. A literature review performed by B.J.A. Pereira et al. demonstrated that only 7.3% of vessel webs were found in the vertebral artery, compared to 91.66% in the carotid artery (3). Because of this, a review of medical literature showed limited case reports on treatment and surgical options for vertebral webs causing posterior circulation stroke. Lenck et al. first reported 3 patients with vertebral webs diagnosed by DSA and having MRI show ischemic strokes in the vascular territory were treated with endovascular stenting and had no recurrence of an ischemic event (4). A literature review reported by Pereira demonstrated that out of 23 vessel webs, 13 were treated with supportive care (including antiplatelets or anticoagulation), eight were treated with angioplasty and stenting (which included the vertebral artery web case), and two were treated with surgery (3). In other literature, Lizhang et al (2019) diagnosed an incidental vertebral artery web on DSA for anterior circulation TIA and was treated successfully with DAPT therapy and atorvastatin 20 mg (5).

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.