Claudication due to adventitial cystic degeneration: A differential diagnosis of peripheral artery disease

Background Cystic adventitial disease (CAD) is an important and rare non-atherosclerotic cause of intermittent claudication and critical limb ischemia. Since the first case of CAD involving the external iliac artery was described by Atkins and Key in 1947, approximately 300 additional cases have been reported. Objectives The aim of this article is to report a rare vascular disorder, predominantly seen in young healthy men with minimal cardiovascular risk factors. Methods We report a rare case of cystic adventitial disease of a young policeman. To confirm the diagnosis, an ultrasonography and a conventional angiography were performed. The therapeutic approach was surgical first. Results The procedure was successful without any complication, and the patient was discharged to home 4 days after procedure. Conclusion While CAD is rare, the diagnosis should be suspected in a young patient who presents with arterial insufficiency and no risk factors for atherosclerosis. Catheter angiography is the investigation of choice in the absence of multislice CT and good MRA. It seems that the treatment that assures the best long-term results is reconstructive arterial bypass surgery.

Carotid Web Phenotype Is Uncommonly Associated With Classic Fibromuscular Dysplasia: A Retrospective Observational Study

Background and Purpose: Carotid web (CaW) is an intimal form of fibromuscular dysplasia (FMD) involving the carotid bulb which has been increasingly recognized as a potential cause of recurrent ischemic strokes. It is overlooked as a separate entity and often dismissed if no coexistent signs of classic FMD changes are observed. We aim to evaluate the frequency of classic FMD in high-yield vascular territories in patients with symptomatic CaW. Methods: This was a retrospective analysis of a symptomatic CaW database of 2 comprehensive stroke centers (spanning September 2014–October 2020). The diagnosis of a CaW during a stroke workup was defined as the presence of a shelf-like linear filling defect in the posterior aspect of the carotid bulb on computed tomography angiography in patients with acute ischemic stroke or transient ischemic attack of undetermined cause after a thorough evaluation. Neck computed tomography angiography and renal conventional angiography images were independently evaluated by two readers blinded to the laterality and clinical details to inspect the presence of underlying classic FMD. Results: Sixty-six patients with CaW were identified. Median age was 51 years (interquartile range, 42–57), and 74% were women. All patients had neck computed tomography angiography (allowing for bilateral vertebral and carotid evaluation), whereas 47 patients had additional digital subtraction angiography (which evaluated 47 carotids ipsilateral to the stroke and 10 contralateral carotids). Internal carotid artery classic FMD changes were noted in only 6 out of 66 (9%) in the ipsilateral carotids. No contralateral carotid or vertebral artery classic FMD changes were observed. Renal artery catheter-based angiography was obtained in 16 patients/32 arteries and only 1 patient/2 renal arteries demonstrated classic FMD changes. Conclusions: CaW phenotype is uncommonly associated with classic FMD changes. Coexistent classic FMD does not constitute a useful marker to corroborate or exclude CaW diagnosis.

Magnetic Resonance Angiography of the Hand Vasculature in Patients With Systemic Sclerosis and Systemic Lupus Erythematosus

Background: When patients with systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) develop digital ischemia, conventional angiography (CA) is traditionally used to assess hand vasculature. Recently, Chang et al described an angiographic classification system for patients with SSc. Conventional angiography uses intravascular contrast agents that are nephrotoxic and vasoconstrictive. Owing to these limitations, this study assesses the use of contrast-enhanced magnetic resonance angiography (MRA) as an alternative to CA to evaluate hand vasculature in patients with digital ischemia. Methods: This retrospective case series reports on 38 contrast-enhanced MRAs of hand vasculature from 30 symptomatic patients with SSc (N = 21) or SLE (N = 9). The radial and ulnar arteries (RA, UA) and the superficial and deep palmar arches were evaluated at standard reference points both quantitatively and qualitatively for their diameter, patency, and Chang classification. Results: In SSc MRAs (n = 26), the UA was significantly smaller than the RA and was occluded in 46%. In SLE MRAs (n = 12), the UA and RA had no difference in diameter and the UA was occluded in 25%. In SSc, the most common Chang classification was type 2 (UA involvement) in 44%. In SLE, the most common Chang classification was type 4 (UA and RA involvement) in 45%, with 18% classified as type 2. Conclusions: Contrast-enhanced MRA used to assess hand vasculature in SSc patients with digital ischemia shows similar patterns of vascular involvement as previously demonstrated by CA. While vascular involvement in SSc predominantly involves the UA, the RA is also frequently involved in SLE.

Mimicking Amyotrophic Lateral Sclerosis: A Case of a Spinal Dural Arteriovenous Fistula

A number of conditions can mimic amyotrophic lateral sclerosis (ALS), which are in general excluded by neurophysiological and neuroimaging investigation. We present a novel mimicking disorder. A 58-year-old male, without relevant past medical history, presented with a 7-year history of progressive paraparesis. On examination, he had bilateral thigh atrophy, fasciculations, and asymmetric paraparesis (severe on the left side). Upper motor neuron signs were present in the lower limbs, with normal sensory examination. Needle EMG disclosed mild chronic neurogenic changes in the lower limbs. Brain and spinal cord neuroimaging was normal, namely, in the dorso-lumbar segment. Lumbar puncture showed mild hyperproteinorachia. Diagnosis of slowly progressive (possible) ALS was established. One year later, he required a bilateral support to walk, and neurological examination revealed weak tendon reflexes, abnormal pinprick, and proprioceptive sensation in the legs. Repeated lumbar MRI showed an extensive spinal cord oedema from T7 to the conus with multiple perimedullary vessel flow voids suggestive of a vascular malformation. Conventional angiography revealed a spinal dural arteriovenous fistula in L2–L3 with the left L4 lumbar branch as the afferent artery. Dural arteriovenous fistula is the most common vascular malformation of the spinal cord, despite being rare. It leads to arterialization of spinal veins, causing venous hypertension, spinal cord oedema, and ischaemia. The clinical picture includes a stepwise, sometimes fluctuant, myeloradiculopathy. In this case, EMG changes did not meet Awaji criteria. This case reinforces the need to critically follow atypical cases to ascertain clinical progression in patients with suspected ALS.

Detection of Collaterals from Cone-Beam CT Images in Stroke

Collateral vessels play an important role in the restoration of blood flow to the ischemic tissues of stroke patients, and the quality of collateral flow has major impact on reducing treatment delay and increasing the success rate of reperfusion. Due to high spatial resolution and rapid scan time, advance imaging using the cone-beam computed tomography (CBCT) is gaining more attention over the conventional angiography in acute stroke diagnosis. Detecting collateral vessels from CBCT images is a challenging task due to the presence of noises and artifacts, small-size and non-uniform structure of vessels. This paper presents a technique to objectively identify collateral vessels from non-collateral vessels. In our technique, several filters are used on the CBCT images of stroke patients to remove noises and artifacts, then multiscale top-hat transformation method is implemented on the pre-processed images to further enhance the vessels. Next, we applied three types of feature extraction methods which are gray level co-occurrence matrix (GLCM), moment invariant, and shape to explore which feature is best to classify the collateral vessels. These features are then used by the support vector machine (SVM), random forest, decision tree, and K-nearest neighbors (KNN) classifiers to classify vessels. Finally, the performance of these classifiers is evaluated in terms of accuracy, sensitivity, precision, recall, F-Measure, and area under the receiver operating characteristics curve. Our results show that all classifiers achieve promising classification accuracy above 90% and able to detect the collateral and non-collateral vessels from images.

Overview of imaging in adult- and childhood-onset Takayasu arteritis

Takayasu Arteritis is an idiopathic large vessel vasculitis, that affects young adults and children and can lead to ischemia and end-organ damage. Vascular imaging is crucial for diagnosis, assessment of disease extent and management of the disease. In this article, we critically review evidence for the clinical use of the different imaging modalities conventional angiography, magnetic resonance imaging, computed tomography, Doppler ultrasound and 18fluorodeoxyglucose positron emission tomography. We thereby focus on their clinical applicability, challenges and specific use in children.

Comparative study of vasodilatation after intra-arterial nicardipine or dantrolene infusion in animal model of cerebral vasospasm

Intra-arterial (IA) infusions of calcium channel blockers (CCBs) have been widely applied in treating medically refractory vasospasm. However, surprisingly little is known regarding their vasodilatory duration. This study was undertaken to compare attributes of nicardipine and dantrolene, focusing on efficacy and capacity for sustained vasodilation. In New Zealand white rabbits (N=22), vasospasm was individually provoked through experimentally induced subarachnoid hemorrhage and confirmed via conventional angiography, grouping animals by IA-infused drug (nicardipine vs dantrolene). Controls received normal saline. After chemoangioplasty, follow-up angiography was performed at intervals of 1-3 hours for 6 hours to compare vasospastic and dilated (ie, treated) arterial diameters. Drug efficacy, duration of action, and changes in mean arterial pressure (relative to baseline) were analyzed by group. Compared with controls, effective vasodilation was evident in both nicardipine and dantrolene test groups after IA infusion. Vasodilatory effects of nicardipine peaked at 1 hour, returning to former vasospastic states at 3 hours. In dantrolene recipients, vasodilation endured longer, lasting >6 hours. This outcome suggests that IA dantrolene infused alone or together with a conventional CCB infusion may be a new means of prolonging vasodilatory effect. Further research is needed to assess durations of IA-infused vasodilatory drug based on perfusion status.

Abstract 1122‐000171: Unusual Multicompartmental Intracranial Hemorrhage After Tenecteplase Administration

Introduction : The 2019 AHA/ASA updated Guidelines for the Early Management of Patients with Acute Ischemic Stroke mention tenecteplase (TNK) as a reasonable therapy in patients without contraindications for IV fibrinolysis who are also eligible to undergo mechanical thrombectomy. We describe a case of acute left MCA ischemic stroke treated with IV TNK (IV bolus of 0.25 mg/kg) followed by mechanical thrombectomy with subsequent multicompartmental intracranial hemorrhages unrelated to area of infraction. Methods : A retrospective review at a single center university hospital was performed for all intravenous TNK administrations outside of a clinical trial setting from October 2020 to July 2021. Results : A 61‐year‐old male with history of HTN and cardiomyopathy (EF<20%). Presented with sudden onset right sided weakness, aphasia and left gaze. Presenting NIHSS was 28. CT head with hyperdense left MCA sign and ASPECTS score of 10. CTA confirmed proximal left MCA M1 segment occlusion. IV TNK was given within 01:23 hours of symptoms onset. Subsequently, patient underwent emergent mechanical thrombectomy for disabling large vessel occlusion stroke. Spontaneous near complete recanalization of left MCA occlusion was noted on initial angiography run with small non flow limiting distal thrombi visualized in the distal MCA territories. Immediate post procedure CT head was negative for any intracranial hemorrhage. Patient’s exam was noted to improve to NIHSS of 2. Approximately 6 hours after the TNK administration, patient became acutely unresponsive with NIHSS of 26. With Glasgow Coma Scale 7 patient required emergent intubation. CT head revealed bilateral cerebellar intraparenchymal hemorrhages, extensive subarachnoid hemorrhage in basal cisterns and within the sulci in bilateral frontotemporal regions, as well as subdural hemorrhages along the falx and tentorial dural folds. Hypertonic saline was administered followed by emergent extraventricular drain placement. Tranexamic acid 1000 mg was given as emergent reversal, fibrinogen level was 155 mg/dL. Despite aggressive medical management and over following 24 hours, exam worsened with loss of pupillary reflexes. Patient was terminally extubated 2 days after initial presentation in accordance with his advance directives. Conclusions : Tenecteplase was a reasonable choice in this case given LVO and disabling stroke. The patient’s neurological exam improved significantly after TNK with evidence of spontaneous recanalization. However, patient’s multicompartmental intracranial hemorrhages unrelated to area of infraction were unusual in the absence of any vascular lesions to predispose hemorrhage based on CT and conventional angiography. Further observational studies are warranted to evaluate similar complications of Tenecteplase administration and their occurrence rates.

P.115 Vessel Wall Imaging of Unusual Childhood Strokes: a Pediatric Case Series

Background: MR-based vessel wall imaging (VWI) has gained influence in the clinical investigations, and management of pediatric strokes. Limitations still exist in interpreting it as a singular modality. Methods: We present 4 pediatric stroke cases with VWI enhancement. Results: Case 1. 4-year old boy with sickle cell anemia, who developed encephalopathy during a hemolytic crisis. MR-VWI revealed bilateral extracranial internal carotid enhanced narrowing, deemed a secondary vasculopathy, with resolution upon follow-up. Case 2. 16-year old male presented with left middle cerebral artery (MCA) infarction. VWI revealed left internal carotid terminus and proximal MCA enhancement. Conventional angiography showed abnormalities in mesentric and hepatic arteries. Stability sustained on anticoagulation and immunosuppressive therapy. Case 3. 10-year old girl, developed bilateral MCA infarctions with enhanced extracranial segments of both ICAs, and narrow PCAs, consistent with Moyamoya vasculopathy. Improved on combined immunosuppressive and anticoagulation therapy. Case 4. 13-year old boy had an episode of right facial weakness, with a normal neurological exam; with enhancement and narrowing in the left extracranial ICA, likely an intramural hematoma from dissection. He responded to dual anticoagulation therapy. Conclusions: In conclusion, these cases illustrate similarities in vessel wall imaging abnormalities under different clinical contexts, with practical utility in longitudinal follow-up and prognostication.

Abstract 1122‐000190: Persistent DWI Signal for 18 Months in Ischemic Stroke Patient with Carotid Web

Introduction : Diagnostic tools for acute ischemic infarcts include the use of DWI sequence on MRI to identify acute infarcts is especially useful since lesions can become hyperintense on this sequence very rapidly (Albers 1998). Over the next 15 days, DWI hyperintensity slowly decreases back to isointense. In some patients, however, there is persistent DWI hyperintensity past 1 month. There are theories that these persistent areas exhibit delayed onset infarct, prolonged ischemia, or perhaps different repair processes (Rivers, et al 2006). To this day, all DWI signals have been known to resolve within a few months even for persistent hyperintensities (Rivers, et al 2006). Carotid webs are a rare form of fibromuscular dysplasia that protrudes from the intimal tissues of carotid arteries. They are shelf‐like projections that grow into the lumen and disrupt normal blood flow (Zhang, et al 2018). These outgrowths are theorized to lead to ischemic strokes due to flow stasis and subsequent embolization of clots that form (Zhang, et al 2018). There is no consensus on the best management of carotid webs, and secondary prevention of recurrent strokes range from medical management to carotid stenting. Methods : This is a case report, and information for the patient was gathered through review of medical records on the EMR. Results : We present a case of ischemic stroke in the right basal ganglia/corona radiata, who presented with left sided weakness. The patient was found to have prediabetes, HTN, and HLD. However, she had recurrence of her symptoms over the next 18 months (figure 1). Repeat MRIs showed persistent DWI hyperintensity that slowly decreased in size and signal intensity over this period but in the same area as the initial infarct. The rest of the work up was only significant for a carotid web in the right internal carotid artery identified on conventional angiography. Ultimately she was managed with medical therapy including aspirin, statin, and antihypertensives. Conclusions : It is unclear whether the carotid web is associated with persistent DWI for such an extended time frame. There is very little research that explores the pathophysiology of ischemic strokes from carotid webs. In addition, there is even less information about the physiology of an evolving infarct that shows persistent DWI signals for such an extended time frame. Further studies that look into carotid webs may help us understand the best long term management in such patients. Future studies that explore the physiology of ischemic strokes that show such persistent DWI signals may elucidate and perhaps expand upon current management options and possibly identify new areas for intervention.