Anticoagulants versus Antiplatelet Treatment in the Medical Management of Carotid Floating Thrombus.

BACKGROUND: Carotid free-floating thrombus (CFT) is a rare cause of stroke describing an intraluminal thrombus that is loosely associated with the arterial wall and manifesting as a filling defect fully surrounded by flow on vascular imaging. Unfortunately, there is no clear consensus among experts on the ideal treatment for this pathology. METHODS: Retrospective analysis of acute ischemic stroke (AIS) and transient ischemic attack (TIA) patients diagnosed with CFT on computed tomography angiogram (CTA) between January 2015-March 2023. We aimed to compare two treatment regimens: anticoagulation (ACT) and antiplatelet (APT) in the treatment of CFT. APT regimens included the use of dual or single antiplatelets (DAPT or SAPT; aspirin, clopidogrel and ticagrelor) and ACT regimens included the use of direct oral anticoagulants, warfarin, heparin or low molecular weight heparin +/- ASA. Patients that underwent mechanical thrombectomy were excluded. RESULTS: During study time there were 8252 acute ischemic stroke hospitalizations, of which 135 (1.63 %) patients were diagnosed with CFT. Sixty-six patients were included in our analysis. Patients assigned to APT were older (60.41years ± 12.82;p < 0.01). Other demographic variables were similar between ACT and APT groups. Complete CFT resolution on repeat vascular imaging was numerically higher at 30 days (58.8 vs 31.6 %, respectively; p = 0.1) and at latest follow-up (70.8 vs 50 %; p = 0.1) on ACT vs APT, respectively without reaching statistical significance. Similarly, there was numerically higher rates of any ICH with ACT compared to APT but it did not achieve statistical significance (27.6 % vs 13.5 %; p = 0.5). There were similar rates of PH1/2 hemorrhagic transformation, independence at discharge and similar hospital length of stay between ACT and APT groups. Patients assigned to APT were more likely to be discharged on their assigned treatment compared to those assigned to ACT (86.5 vs 55.2 %; p < 0.001). The rate of 30-day recurrent stroke was comparable among ACT and APT at 30 days (3.4 vs 0 %; p = 0.1, respectively). Subgroup analysis comparing exclusive ACT vs Dual APT lead to similar results. CONCLUSION: Our study showed comparable efficacy and safety outcomes in CFT patients who were exclusively managed medically with ACT vs APT. Larger prospective studies are needed.

Carotid free-floating thrombus in patients with acute ischaemic stroke and active cancer.

In patients with ischaemic stroke, a carotid free-floating thrombus (CFFT) raises diagnostic and therapeutic challenges. We describe two women, each taking tamoxifen for invasive non-metastatic breast cancer, who developed large-vessel occlusion ischaemic strokes. The first had a CFFT 24 hours after receiving intravenous thrombolysis and mechanical thrombectomy; the thrombus completely resolved after 1 week of therapeutic anticoagulation. The second had a tandem occlusion with a CFFT at admission; her neurological deficits rapidly improved after intravenous thrombolysis without needing a mechanical thrombectomy. However, subsequently, under therapeutic anticoagulation, distal migration of the CFFT caused a recurrent large vessel occlusion ischaemic stroke, requiring mechanical thrombectomy. The CTFF in both cases appeared to relate to a cancer-related prothrombotic state. Both received long-term oral anticoagulation and their tamoxifen was switched to anastrozole. At 3 months, both were functionally independent without recurrent vascular events.

Unstable Carotid Artery Thrombus in a Patient With COVID-19 Infection.

We present a case of an unvaccinated, 43-year-old African American female patient with COVID-19 infection and clinical evidence of a left hemispheric stroke. A non-occlusive thrombus with a radiographic target lesion was identified on computed tomography angiography (CTA). A multi-disciplinary discussion regarding concern for embolization was provided due to its unstable nature, as well as evidence of recent stroke. Given her acute COVID-19 infection, symptomatology, and radiographic findings, it was concluded that the etiology of her stroke appeared most consistent with a hypercoagulable-related embolism rather than an atheroembolic event. The patient underwent left carotid artery thrombectomy with bovine patch angioplasty. Operative findings included: left carotid thrombus, minimal plaque after evacuation of the thrombus, and a small proximal internal carotid artery diameter. Given concern for stenosis with primary repair a bovine pericardial patch angioplasty was performed. We present a paradigm for extracranial carotid thrombectomy with therapeutic anticoagulation for COVID-related spontaneous arterial thrombosis.

Endovascular Thrombectomy for a Progressive Stroke Patient With a High-Burden Carotid Free-Floating Thrombus.

Carotid free-floating thrombus (FFT) is a rare cause of acute ischemic events. The optimal management of carotid FFT remains unclear. The optimal and individualized management of carotid FFT should be determined based on the underlying etiology, clinical manifestation, and imaging characteristics. we reported a case with endovascular thrombectomy for a progressive stroke patient with a high-burden carotid free-floating thrombus. ANN NEUROL 2024;95:362-364.

High Contrast Detection of Carotid Neothrombus with Strong Near-Infrared Absorption Selenium Nanosphere Enhanced Photoacoustic Imaging.

Background: Carotid artery thrombosis is the leading cause of stroke. Since there are no apparent symptoms in the early stages of carotid atherosclerosis onset, it causes a more significant clinical diagnosis. Photoacoustic (PA) imaging provides high contrast and good depth information, which has been used for the early detection and diagnosis of many diseases. Methods: We investigated thrombus formation by using 20% ferric chloride (FeCl3) in the carotid arteries of KM mice for the thrombosis model. The near-infrared selenium/polypyrrole (Se@PPy) nanomaterials are easy to synthesize and have excellent optical absorption in vivo, which can be used as PA contrast agents to obtain thrombosis information. Results: In vitro experiments showed that Se@PPy nanocomposites have fulfilling PA ability in the 700 nm to 900 nm wavelength range. In the carotid atherosclerosis model, maximum PA signal enhancement up to 3.44, 4.04, and 5.07 times was observed by injection of Se@PPy nanomaterials, which helped to diagnose the severity of carotid atherosclerosis. Conclusion: The superior PA signal of Se@PPy nanomaterials can identify the extent of atherosclerotic carotid lesions, demonstrating the feasibility of PA imaging technology in diagnosing carotid thrombosis lesion formation. This study demonstrates nanocomposites and PA techniques for imaging and diagnosing carotid thrombosis in vivo.

An unusual case of carotidynia preceding recurrent ischemic stroke with carotid thrombosis in a patient with systemic lupus erythematosus.

Carotid artery thrombosis following carotidynia is an uncommon manifestation of systemic lupus erythematosus. We report the case of a woman without evidence of a lupus flare-up who presented with the unusual clinical course of ipsilateral carotidynia and recurrent ischemic stroke due to carotid thrombosis. To our knowledge, this is the first case of such an unusual manifestation in lupus and highlights distinctive challenges in the diagnosis and management of carotid artery thrombosis following carotidynia.

Multiple Sites of Arterial Thrombosis in A 35-Year Old Patient after ChAdOx1 (AstraZeneca) Vaccination, Requiring Emergent Femoral and Carotid Surgical Thrombectomy.

BACKGROUND: Vaccine Induced Thrombotic Thrombocytopenia (VITT) is a rare complication following ChAdOx1 (AstraZeneca) vaccination. Venous thrombosis in unusual sites such as splachnic or intracranial thrombosis, is the commonest manifestation. CASE REPORT: We report a 35-year-old male patient who presented with acute left leg ischemia and thrombocytopenia 11-days after vaccination requiring emergent thrombectomy. During work-up, a localized thrombus was detected in the left carotid bifurcation mandating carotid thrombectomy. Localized right iliac thrombus causing a non-limiting flow stenosis was treated conservatively. The platelet aggregating capacity of patient's plasma was confirmed in a functional assay, thereby establishing VITT. CONCLUSION: To the best of our knowledge this is the first case presenting multiple arterial thromboses requiring surgical treatment after ChAdOx1 vaccination.

COVID-19-associated ischaemic stroke due to underlying carotid artery thrombosis in a healthy young woman.

SARS-CoV-2 has proven its versatility in host presentations; one such presentation is a hypercoagulable state causing large-vessel thrombosis. We report a case on a previously asymptomatic COVID-19-positive patient presenting with an acute ischaemic stroke and an incidental left internal carotid artery thrombus. The patient's medical, social and family history and hypercoagulability screening excluded any other explanation for the left carotid thrombus or stroke, except for testing positive for the COVID-19. This case explores the known hypercoagulable state associated with COVID-19 and the effect of the virus on the host's immune response. It also questions whether administration of recombinant tissue plasminogen activator (t-PA), according to the American Heart Association guidelines, following a negative head CT for haemorrhagic stroke is safe without prior extended imaging in this patient population. We recommend, in addition to obtaining a non-contrast CT scan of the brain, a CT angiogram or carotid duplex of the neck be obtained routinely in patients with COVID-19 exhibiting stroke symptoms before t-PA administration as the effects may be detrimental. This recommendation will likely prevent fragmentation and embolisation of an undetected carotid thrombus.

Intraluminal carotid thrombosis and acute ischemic stroke associated with COVID-19.

COVID-19 (Coronavirus disease 2019) caused by SARS-CoV-2 has a diverse constellation of neurological manifestations that include encephalopathy, stroke, Guillain-Barré syndrome, myelitis, and encephalitis. Intraluminal carotid thrombi (ILT) are infrequent lesions seen in only 1.6% of patients with acute ischemic stroke. Underlying atherosclerosis is the most common lesion associated with ILT formation. However, with COVID-19, we have encountered ILT in patients without significant atherosclerotic disease. The endothelial inflammation and hypercoagulable state associated with COVID-19 pose a risk of arterial and venous thromboembolism and could have contributed to this presentation although the exact pathophysiology and optimal treatment of ILT in COVID-19 remain elusive. Herein, we present a series of ischemic stroke patients with carotid ILT in the setting of a recent SARS-CoV-2 infection.

Short-Term Cessation of Dabigatran Causes a Paradoxical Prothrombotic State.

OBJECTIVE: It is unclear if stopping treatment with dabigatran, a new oral anticoagulant (NOAC), induces a paradoxical rebound prothrombotic state. We investigated if short-term (1-3 days) dabigatran cessation is associated with a higher thrombus volume than expected from a simple reversal of the anticoagulant effect. METHODS: Ten-week-old C57Bl/6 mice (n = 338) received one of the following oral treatments: phosphate-buffered saline (PBS), dabigatran for 7 days with or without 1 to 4 day cessation, and aspirin in either a single dose or daily for 7 days. Some of the animals that ceased dabigatran for 1 to 3 days received single-dose aspirin. Thereafter, we induced FeCl3 -mediated carotid thrombosis in 130 mice, after which we performed micro computed tomography thrombus imaging. The other 208 mice underwent coagulation assays or platelet function tests. As an explorative pilot study, we reviewed the medical records of 18 consecutive patients with NOAC cessation-related cerebral infarction in a large acute stroke cohort. RESULTS: We observed a ~ 40% higher volume of carotid thrombus after dabigatran cessation at 1 to 3 days than after vehicle treatment and showed that this effect could be prevented by single-dose aspirin pretreatment. Dabigatran cessation unduly increased platelet aggregability for 2 days after drug cessation, an effect mediated through thrombin or arachidonic acid, which effect was significantly attenuated by single-dose aspirin pretreatment. In patients, short-term (≤ 3 days) cessation of NOAC therapy, compared with longer-term (≥ 5 days) cessation, tended to be associated with relatively high stroke severity. INTERPRETATION: We provide the first preclinical evidence that a rebound prothrombotic state follows short-term cessation of dabigatran therapy. ANN NEUROL 2021;89:444-458.

Use of distal protection filter device for rescue mechanical thrombectomy for symptomatic free-floating thrombus of the cervical internal carotid artery.

BACKGROUND: Intraluminal free floating thrombus (FFT) of the cervical internal carotid artery (ICA) is a potentially high-risk lesion for recurrent ischemic strokes, with no single optimal treatment established. OBJECTIVE: To describe a novel interventional technique for mechanical thrombectomy of intraluminal free floating thrombus using a distal protection filter device and aspiration. METHODS: We identified two cases where anticoagulation was contraindicated in patients with intraluminal FFT and minimal underlying stenosis. In both cases, a distal protection device was used to extract the thrombus under proximal flow arrest and aspiration. RESULTS: Mechanical thrombectomy was successful in both cases, one with "en bloc" removal of the thrombus and one with piecemeal removal. Neither case showed any residual angiographic stenosis or atherosclerotic disease. CONCLUSION: Mechanical thrombectomy using a distal protection device is a novel and technically feasible approach for select cases of cervical intraluminal thrombus. This may represent a therapeutic option in select cases with high risk of anticoagulation and in the unusual subset of younger patients with minimal atherosclerotidc disease.

Multimodal Predictive Modeling of Endovascular Treatment Outcome for Acute Ischemic Stroke Using Machine-Learning.

BACKGROUND AND PURPOSE: This study assessed the predictive performance and relative importance of clinical, multimodal imaging, and angiographic characteristics for predicting the clinical outcome of endovascular treatment for acute ischemic stroke. METHODS: A consecutive series of 246 patients with acute ischemic stroke and large vessel occlusion in the anterior circulation who underwent endovascular treatment between April 2014 and January 2018 was analyzed. Clinical, conventional imaging (electronic Alberta Stroke Program Early CT Score, acute ischemic volume, site of vessel occlusion, and collateral score), and advanced imaging characteristics (CT-perfusion with quantification of ischemic penumbra and infarct core volumes) before treatment as well as angiographic (interval groin puncture-recanalization, modified Thrombolysis in Cerebral Infarction score) and postinterventional clinical (National Institutes of Health Stroke Scale score after 24 hours) and imaging characteristics (electronic Alberta Stroke Program Early CT Score, final infarction volume after 18-36 hours) were assessed. The modified Rankin Scale (mRS) score at 90 days (mRS-90) was used to measure patient outcome (favorable outcome: mRS-90 ≤2 versus unfavorable outcome: mRS-90 >2). Machine-learning with gradient boosting classifiers was used to assess the performance and relative importance of the extracted characteristics for predicting mRS-90. RESULTS: Baseline clinical and conventional imaging characteristics predicted mRS-90 with an area under the receiver operating characteristics curve of 0.740 (95% CI, 0.733-0.747) and an accuracy of 0.711 (95% CI, 0.705-0.717). Advanced imaging with CT-perfusion did not improved the predictive performance (area under the receiver operating characteristics curve, 0.747 [95% CI, 0.740-0.755]; accuracy, 0.720 [95% CI, 0.714-0.727]; P=0.150). Further inclusion of angiographic and postinterventional characteristics significantly improved the predictive performance (area under the receiver operating characteristics curve, 0.856 [95% CI, 0.850-0.861]; accuracy, 0.804 [95% CI, 0.799-0.810]; P<0.001). The most important parameters for predicting mRS 90 were National Institutes of Health Stroke Scale score after 24 hours (importance =100%), premorbid mRS score (importance =44%) and final infarction volume on postinterventional CT after 18 to 36 hours (importance =32%). CONCLUSIONS: Integrative assessment of clinical, multimodal imaging, and angiographic characteristics with machine-learning allowed to accurately predict the clinical outcome following endovascular treatment for acute ischemic stroke. Thereby, premorbid mRS was the most important clinical predictor for mRS-90, and the final infarction volume was the most important imaging predictor, while the extent of hemodynamic impairment on CT-perfusion before treatment had limited importance.

The resolution of carotid arterial thrombus by oral anticoagulation after IV thrombolysis for chemotherapy-induced stroke: A case report.

RATIONALE: Cancer-related stroke has been regarded as an emerging subtype of ischemic event. Acute treatment for this subtype may include the antiplatelet agents, anticoagulants, or endovascular intervention. PATIENT CONCERNS: A 63-year-old woman with sudden-onset right hemiparesis and conscious change was sent to our emergency department. The patient had underlying sigmoid adenocarcinoma and received chemotherapy FOLFIRI (FOL, folinic acid; F, fluorouracil; and IRI, irinotecan) with targeted therapy cetuximab following lower anterior resection since the diagnosis was made. DIAGNOSES: Brain magnetic resonance angiography revealed a filling defect in left carotid bulb, and neurosonography showed a thick atherosclerotic plaque (size 4.9 mm) in the left internal carotid artery on day 5 after the onset of stroke. INTERVENTIONS: During the first three hours after onset, administration of IV tissue plasminogen activator did not resolve the thrombus. Dabigatran (110 mg bid) started on day 7. OUTCOMES: The atherosclerotic plaque dissolved on day 24. The patient recovered her muscle strength but still had nonfluent speech in mild extent. LESSONS: Thrombolytic and anticoagulant medications in this patient suggested the thrombus formation with fibrin-rich content which may be attributable to both cancer and chemotherapy. Dabigatran, an oral anticoagulant, had a benefit for this subtype of ischemic stroke among patients with cancer.

Common Carotid Artery Occlusion in a Young Patient: Can Large-Vessel Stroke Be the Initial Clinical Manifestation of Coronavirus Disease 2019?

BACKGROUND: The occurrence of large-vessel occlusion in young patients with coronavirus disease 2019 (COVID-19) infection has been exceedingly rare. An extensive review of reported studies revealed a few reported cases. In the present report, we have described the clinical presentation, radiological findings, and outcome of large-vessel occlusion in a young patient with COVID-19 and reviewed the pertinent reported data on this condition. CASE DESCRIPTION: A 31-year-old woman was in her usual state of health until she had presented with a 3-day history of right-sided weakness, slurred speech, and decreased vision. The patient had been taken to several hospitals where she had been treated conservatively with analgesics and discharged. Shortly thereafter, her weakness had become progressive. She had become severely dysarthric and unresponsive. On arrival to the emergency department, her physical examination revealed that she was stuporous, with a Glasgow coma scale of 10 (eye response, 3; verbal response, 2; motor response, 5). The National Institutes of Health Stroke Scale score was 19 on presentation. Brain computed tomography and computed tomography venography revealed an occluded left internal carotid artery and left middle cerebral artery with subacute left middle cerebral artery territory infarction and midline shift. Computed tomography angiography revealed complete occlusion of the left common carotid artery. An emergent decompressive craniectomy was successfully performed. The patient was shifted to the intensive care unit. She was later found to be positive for COVID-19. CONCLUSIONS: Although rare, patients with COVID-19 can present with large-vessel occlusion. Prompt identification of COVID-19-related coagulopathy is essential to assess young patients with clinical manifestations of infarction.

Macrothrombosis and stroke in patients with mild Covid-19 infection.

Coronavirus disease 2019 (COVID-19) is a pandemic disease currently affecting millions of people worldwide. Its neurological implications are poorly understood, and further study is urgently required. A hypercoagulable state has been reported in patients with severe COVID-19, but nothing is known about coagulopathy in patients with milder disease. We describe cases of patients in New York City presenting with stroke secondary to large vessel thrombosis without occlusion, incidentally found to have COVID-19 with only mild respiratory symptoms. This is in contrast to the venous thrombosis and microangiopathy that has been reported in patients with severe COVID-19. Our cases suggest that even in the absence of severe disease, patients with COVID-19 may be at increased risk of thrombus formation leading to stroke, perhaps resulting from viral involvement of the endothelium. Further systematic study is needed because this may have implications for primary and secondary stroke prevention in patients with COVID-19.