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.

Early vs late anticoagulation in acute ischemic stroke with indications outside atrial fibrillation

BACKGROUND

Current literature lacks guidance on the safety of administering anticoagulation in acute ischemic stroke with emergent indications that require anticoagulation other than atrial fibrillation. Therefore, we tend to rely on studies investigating acute ischemic stroke in atrial fibrillation for anticoagulation recommendations.

METHODS

We retrospectively reviewed data for patients with acute ischemic stroke who had a non-atrial fibrillation emergent indication for anticoagulation (e.g., intra-arterial thrombus, intracardiac thrombus, acute coronary syndrome, acute limb ischemia, deep vein thrombosis and pulmonary embolism) diagnosed within 3 days of acute ischemic stroke. Patients who received anticoagulation ≤ 3 days of stroke onset (Group A) were compared to those who either received it afterwards or did not receive it at all (Group B).

RESULTS

Out of the 558 patients, only 88 patients met our inclusion criteria. Of the total cohort, 55.7 % patients were males, and basic demographics were similar in both groups except for milder strokes in Group A (national institute of health stroke scale 6 vs. 12.5, p = 0.03). Only 2 patients in Group A and 1 patient in Group B developed intracranial hemorrhage, which was not statistically significant. Group A patients had a lower incidence of both new diagnosis (2 % vs. 34.2 % %, p < 0.001) and propagation of an established venous thromboembolism. They also had a lower rate of any thromboembolic complication (2 % vs. 42 %, p < 0.001).

CONCLUSION

Early anticoagulation (i.e., ≤ 3 days) in non-atrial fibrillation ischemic stroke patients with an emergent indication may be safe and carry a lower risk of thromboembolic complications than later anticoagulation.

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.

Safety and effectiveness of anticoagulation in the management of acute stroke and transient ischemic attack due to intracranial and extracranial non-occlusive thrombus

INTRODUCTION

The awareness of nonocclusive thrombus has increased with the increasing frequency of imaging methods used for acute ischemic stroke; however, the best treatment for nonocclusive thrombi is still unknown. In this study, we examined how anticoagulants affect supra-aortic artery nonocclusive thrombus and clinical outcomes.

MATERIALS AND METHODS

This study included 52 patients with transient ischemic attack or stroke who were diagnosed with nonocclusive thrombi on computed tomography angiography at admission. Patients were treated with anticoagulant treatment and grouped according to treatment modality (either unfractionated heparin or low molecular weight heparin) and treatment duration. Primary safety outcome was major bleeding defined as immediate and clnically significant hemorrhage. Anticoagulant treatment was continued until the thrombus was resolved as determined by consecutive weekly computed tomography angiography controls. After thrombus resolution, treatment was directed according to the underlying etiology. Antiaggregation treatment was the preferred treatment after thrombus resolution for patients with no observed etiology.

RESULTS

The affected internal carotid arteries were most frequently located in the cervical segment (48 %). Complete resolution was achieved within 2 weeks in 50 patients (96 %). The involved vasculature included the following: the extracranial carotid artery segments (n = 26, 50 %), intracranial ICA segments (n = 10, 19 %), basilar artery segments (n = 8, 15 %) and MCA segments (n = 7, 13 %). The most common underlying pathologies were atherosclerosis (n = 17), atrial fibrillation (n = 17), undetermined embolic stroke (n = 8), dissection (n = 7), and malignancy (n = 2). No symptomatic intra- or extracranial bleeding complications due to anticoagulant use were observed in any patient during the study period. A good functional outcome (modified Rankin scale score 0-2) was achieved in 49 patients (94 %) at 3 months. There was no significant difference between treatment type and duration in terms of reinfarction (p = 0.97 and p = 0.78, respectively).

CONCLUSION

Anticoagulant treatment is safe and effective in symptomatic patients with intracranial or extracranial artery nonocclusive thrombus, regardless of the anticoagulant type, thrombus location and size.

Intraluminal carotid thrombus leading to postpartum stroke: a case study

BACKGROUND

Intraluminal non-occlusive thrombus (ILT) is a rare cause of ischemic stroke. Although in most cases ILT is associated with arterial wall disorders, it has also been documented in patients with thrombophilic conditions.

CASE REPORT

We present a case of carotid ILT in a 38-year-old puerperal woman with pregnancy-induced hypercoagulability. Following in vitro fertilization pregnancy, she experienced acute left-sided weakness 9 days after delivery. CT angiography revealed an intraluminal filling defect in the right carotid bulb, suggestive of a thrombus, along with ipsilateral MCA sub-occlusion. Mechanical thrombectomy was performed, achieving complete vessel recanalization without any endovascular intervention on the carotid ILT. Comprehensive evaluation excluded any underlying carotid vessel wall disease (such as atherosclerosis, inflammatory diseases, arterial dissection, focal dysplasia), inherited or acquired thrombophilia, and the sole prothrombotic risk factor identified was the puerperium. Histological thrombus analysis showed fibrin/platelet-rich material with significant macrophage infiltration (consistent with an intermediate/organized thrombus, suggesting potential embolization from a pre-existing carotid ILT). Anti-thrombotic treatment (acetylsalicylic acid 100 mg and enoxaparin 6000 UI) resulted in complete thrombus resolution at follow-up.

CONCLUSION

ILT should be considered a potential case of embolic stroke in pregnancy or puerperium. Vessel imaging is essential for diagnosis. Histological thrombus analysis can provide insights into the pathophysiological mechanisms of stroke.

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.

Carotid Free-Floating Thrombus Treated With a Combined Technique Using Embotrap III for Distal Protection

Carotid free-floating thrombus (FFT) is a rare condition in patients with acute ischemic stroke. Recently, endovascular therapy for carotid FFT has been increasingly reported, but the strategy has not yet been established. We report a case of an acute stroke patient with a carotid FFT, who was successfully treated with a combination of the direct aspiration first-pass technique (ADAPT) and the Embotrap III (Cerenovus, Irvine, CA), specifically designed to prevent distal embolization. We propose the utility of distal embolic protection with Embotrap III for the treatment of patients with carotid FFT. A 71-year-old man who presented with sudden left hemiparesis was admitted to our hospital. Ultrasonography on admission revealed severe stenosis and an FFT at the origin of the right internal carotid artery. Thrombectomy with an aspiration catheter, accompanied by a stent retriever with distal basket Embotrap III for distal protection, was performed. After the FFT was safely aspirated, a carotid Wallstent (Boston Scientific, Marlborough, MA) was deployed in the stenosis. Follow-up ultrasonography showed neither FFT nor in-stent protrusion. The patient did not experience recurrence, as per clinical or radiological findings, and was discharged on day 11 without any neurological deficits. Embotrap III may be useful for a patient with a carotid FFT as distal protection during mechanical thrombectomies.

Contrast-enhanced ultrasound reveals free-floating thrombus in carotid artery: The cause of stroke is surprisingly plaque rupture

BACKGROUND

Acute stroke poses a serious threat to people's health. The occurrence of a thrombus following the rupture of vulnerable plaques in the carotid artery is a significant contributor to the development of stroke. In previous case reports, it has been challenging to visualize tiny ulcerations within carotid artery plaques using computed tomography angiography (CTA) and digital subtraction angiography (DSA), even when the rupture of the plaque leads to the formation of a free-floating thrombus (FFT). However, in this particular case, contrast-enhanced ultrasound (CEUS) was able to overcome this limitation and provide a more precise assessment, confirming that the FFT formation was indeed a result of plaque rupture rather than any other potential causes. Cases that utilize CEUS to visualize the formation of ulcers and FFT resulting from plaque rupture are even more rare. As such, we present this case to shed light on this infrequent phenomenon.

CASE SUMMARY

In this case study, we present a 65-year-old male patient who was admitted to the hospital due to headache and abnormal mental behavior for one day. During the routine cervical artery ultrasound examination upon admission, we detected the presence of plaque in the right internal carotid artery of the patient, resulting in luminal stenosis. Additionally, we observed suspected hypoechoic material at the distal end of the plaque. After undergoing CEUS examination, it was definitively determined that an ulcer had formed and a FFT had developed due to the rupture of carotid artery plaque. Subsequent CTA and DSA examinations further confirmed the presence of the FFT. The magnetic resonance imaging (MRI) reveals an acute lacunar infarction in the head of the right caput nuclei caudate, which strengthens the potential link between the patient's neurological and psychiatric symptoms observed during admission. The patient received prompt antiplatelet therapy and underwent cervical artery stenting surgery with the assistance of a distal embolic protection device. Following the procedure, the patient was discharged on the fourth day and experienced a complete recovery.

CONCLUSION

CEUS is a valuable tool for visualizing FFT resulting from the rupture of vulnerable plaques in the carotid artery.

Acute phase supra-aortic intraluminal thrombus signal changes on magnetic resonance angiography: A case series: Intraluminal thrombus signal changes on MRA

BACKGROUND AND OBJECTIVES

Intraluminal thrombus (ILT) is a relatively rare cause of stroke. MRI/MRA is increasingly used for stroke patients eligible for acute treatment. Radiological ILT characteristics have never been studied systematically on MRA. We aimed to analyse signal changes and other radiological characteristics of ILT in the acute phase on MRA in a case series of ILT patients.

MATERIALS AND METHODS

Consecutive stroke patients registered in our stroke database between January 2013 and September 2022 were screened for supra-aortic ILT on MRA, in whom MRA was the first supra-aortic vessel imaging performed. Twelve patients were included for analysis. Radiological analysis on MRA included ILT localisation, diameter of the free-floating ILT component, total ITL length, degree of stenosis caused by ILT, and ILT signal intensity.

RESULTS

Median age was 65 years and 92% were men. Median time interval between stroke onset and MRA was 0.5 days. Atherosclerosis was the underlying ILT aetiology in half of the patients. The most frequent ILT localisation was the internal carotid artery, always involving the C1 segment. Median ILT diameter was 4.35 mm, median length 20.9 mm, median stenosis 65%, and with a homogeneous hypointensity of the ILT in 67% and a mixed hypo-hyperintensity in 33% (with ILT showing central hyperintensity surrounded by peripheral hypointensity).

DISCUSSION

When observed on MRA, ILT showed a homogeneous hypointensity in two-thirds and a mixed hypo-hyperintensity in one third of patients. In future studies, follow-up MRA scans should be performed to analyse whether these signal changes are time-related or influenced by antithrombotic treatment for ILT.

Symptomatic carotid artery intraluminal thrombus: risk of medical management failure and distal embolization

BACKGROUND

Carotid artery intraluminal thrombus (ILT), or free-floating thrombus, is an uncommon cerebrovascular entity with considerable equipoise regarding its clinical management. Likewise, in patients treated with medical management (MM), distal embolization and/or intracranial hemorrhage (ICH) may still occur.

METHODS

All patients with symptomatic ILT from 2016 to 2023 were identified from our tertiary care institution. Patients with MM failure (recurrent cerebral ischemia and/or symptomatic ICH) were compared with patients with MM non-failure. Differences in ILT volume and length were calculated. Receiver operator characteristic (ROC) curve analysis was used to identify the cut-off volume and length for risk of MM failure.

RESULTS

In total, 45 patients with ILT were identified with 41 treated with frontline MM. Of these 41 patients treated with MM, seven (17%) had MM failure with six (14.6%) having new embolic stroke and one (2.3%) with symptomatic ICH. Patients with MM failure had a significantly higher mean thrombus volume than MM non-failure patients (257 mm3 vs 59.6 mm3, P=0.0006). Likewise, patients with MM failure had significantly longer thrombus on average (21 mm vs 6.6 mm, P=0.0009). ROC curve analysis showed that an ILT volume of 90 mm3 resulted in a sensitivity of 71.4% and specificity of 85.3% for MM failure (AUC 0.775; CI 0.55 to 1.0, P=0.023).

CONCLUSIONS

Carotid ILTs that fail MM are significantly larger and longer. These findings suggest that a thrombus volume of 90 mm3 may serve as a guide for intervention with good sensitivity and specificity for risk of MM failure.

Carotid free-floating thrombus stemming from carotid web: co-occurrence of two rare causes of ischemic stroke

BACKGROUND

Carotid web (CaW) and carotid free-floating thrombus (CFFT) are rare yet critical causes of ischemic stroke in young adults.

CASE PRESENTATION

A 54-year-old woman presented with a fluctuating right sensory-motor faciobrachial syndrome. A brain MRI scan revealed multiple small recent asynchronous cortico-subcortical ischemic foci in the vascular territory of the left internal carotid artery. A CT angiography identified a CFFT in the left internal carotid artery arising from an underlying CaW. The patient was treated with excellent clinical outcomes with carotid artery stenting and dual antiplatelet therapy.

CONCLUSIONS

We provide a structured pathophysiological rationale connecting CaW and CFFT and highlight pivotal therapeutic implications. Further studies are needed to investigate this relationship and guide assessment and treatment.

Risk of Stroke Recurrence After Intravenous Thrombolysis in Patients with Symptomatic Carotid Stenosis

OBJECTIVE

To assess if intravenous thrombolysis (IVT) affects the risk of recurrent preoperative cerebrovascular events before carotid surgery or stenting in patients with symptomatic ≥ 50% carotid stenosis.

METHODS

Three cohorts of symptomatic ≥ 50% carotid stenosis patients were merged. To make the control group relevant, we excluded patients not presenting with stroke on the day of symptom onset. The risk of preoperative cerebrovascular events up to 30 days was compared between the IVT-treated and non-IVT-treated.

RESULTS

In total, 316 patients were included, 64 (20%) treated with IVT. Those treated with IVT had similar risk of recurrent ipsilateral ischemic stroke or retinal artery occlusion (12% at day 7, 12% at day 30) as those not treated (9% at day 7, 15% at day 30; adjusted HR 0.9, 95% CI 0.4-2.2). There was a tendency (p = 0.09) towards time-dependency in the data where the recurrence risk was higher in IVT-treated at day 0 (6% in IVT-treated, 1% in non-IVT-treated, OR 5.5, 95% CI 1.2-25.4, p = 0.03). This was not significant when adjusting for co-factors (adjusted OR 4.4, 95% CI 0.9-21.8, p = 0.07) and was offset by a later risk decrease, with no remaining risk difference between IVT-treated and non-IVT-treated at day 7.

CONCLUSIONS

Intravenous thrombolysis treatment does not seem to affect the risk of recurrent ipsilateral ischemic stroke in patients with symptomatic ≥50% carotid stenosis: The risk is high in both IVT-treated and non-IVT-treated. However, there might be a risk increase on the day of IVT treatment that is offset by a risk decrease during the first week.

Neuroimaging Spectrum in COVID-19 Infection: A Single-Center Experience

Background and Purpose  The ongoing coronavirus disease 2019 (COVID-19) pandemic is a multisystemic disease and involvement of the nervous system is well established. The neurological and neuroimaging features of the disease have been extensively evaluated. Our study aimed to elucidate the neuroradiological findings in COVID-19 infected patients admitted to our institute during the first and second waves of the pandemic in India. Methods  This was a single-center retrospective study of all COVID-19 positive patients who underwent neuroimaging between March 2020 and May 2021. The presenting neurological complaints, the imaging findings in computed tomography (CT) imaging, and/or magnetic resonance imaging (MRI) were recorded. They recorded the findings in the subheadings of ischemic stroke, hemorrhagic stroke, parainfectious demyelination, acute encephalitis syndrome, and changes of global hypoxic changes. Patients with age-related, chronic, and incidental findings were excluded. Results  The study comprised of 180 COVID-19 positive patients who underwent neuroimaging. CT scan was performed for 169 patients, MRI for 28, and a combination of both CT and MRI was performed for 17 patients. Seventy percent of patients were males, and median age was 61.5 years (interquartile range: 48.25-70.75). Out of the 180 patients, 66 patients had nonspecific findings that could not be attributed to COVID-19 infection. In the remaining 114 patients, 77 (42.7%) had ischemic findings, while 22 (12.2%) had hemorrhagic stroke. Hypoxic ischemic changes were noted in five patients. The rest of the patients had a spectrum of changes including, cerebellitis (3), tumefactive demyelination (1), COVID-19-associated encephalitis (1), hemorrhagic acute demyelinating encephalomyelitis (1), transverse myelitis (1), cytotoxic lesions of corpus callosum (1), Guillain-Barre syndrome (1), and COVID-19-associated microhemorrhages (1). Conclusion  Neurological manifestations of COVID-19 infection are not uncommon, and our understanding of this topic is expanding. A complex interplay of neurotropism and direct central nervous system invasion, immune activation and cytokine storm, vasculitis, and parainfectious processes are implicated in the pathophysiology. While the most common imaging finding was ischemic stroke, followed by hemorrhagic stroke, a diverse range of parainfectious findings was also noted in our study.

Carotid free-floating thrombus in COVID-19: a cerebrovascular disorder of cytokine storm-related immunothrombosis

BACKGROUNDS

Several neurological manifestations, including stroke, have been reported in COVID-19 patients. The putative role of the COVID-19-related hyperinflammatory state in cerebrovascular disorders remains unclear.

METHODS

From March 2020 to September 2021, we searched for patients who exhibited an ischemic stroke related to carotid free-floating thrombus (CFFT) to investigate its incidence and relationship with COVID-19.

RESULTS

Of 853 ischemic strokes referred to our Stroke Centre during the study period, 5.7% (n = 49) were positive for SARS-CoV-2. Six had CFFT, of which two tested positive for SARS-CoV-2 (2/49 = 4.1%), and four did not (4/802 = 0.5%). The former were two middle-aged men suffering from COVID-19 pneumonia. Floating thrombi were promptly extracted by endarterectomy and endovascular thrombectomy, respectively, with no early and long-term complications. Notably, our COVID-19 patients exhibited little or no atherosclerosis burden on CT angiography, markedly elevated D-dimer levels, and extensive thrombus length.

CONCLUSIONS

COVID-19-induced immunothrombosis possibly played a significant pathogenic role in CFFT.

Aetiology of extracranial carotid free-floating thrombus in a prospective multicentre cohort

Background

Carotid free-floating thrombi (FFT) in patients with acute transient ischaemic attack (TIA)/stroke have a high risk of early recurrent stroke. Management depends on aetiology, which can include local plaque rupture, dissection, coagulopathy, malignancy and cardioembolism. Our objectives were to classify the underlying aetiology of FFT and to estimate the proportion of patients with underlying stenosis requiring revascularisation.

Methods

We prospectively enrolled consecutive patients presenting to three comprehensive stroke centres with acute TIA/stroke and ipsilateral internal carotid artery FFT. The aetiology of FFT was classified as: carotid atherosclerotic disease, carotid dissection, cardioembolism, both carotid atherosclerosis and cardioembolism, or embolic stroke of uncertain source (ESUS). Patients with carotid atherosclerosis were further subclassified as having ≥50% or <50% stenosis.

Results

We enrolled 83 patients with confirmed FFT. Aetiological assessments revealed 66/83 (79.5%) had carotid atherosclerotic plaque, 4/83 (4.8%) had a carotid dissection, 10/83 (12%) had both atrial fibrillation and carotid atherosclerotic plaque and 3/83 (3.6%) were classified as ESUS. Of the 76 patients with atherosclerotic plaque (including those with atrial fibrillation), 40 (52.6%) had ≥50% ipsilateral stenosis.

Conclusions

The majority of symptomatic carotid artery FFT are likely caused by local plaque rupture, more than half of which are associated with moderate to severe carotid stenosis requiring revascularisation. However, a significant number of FFTs are caused by non-atherosclerotic mechanisms warranting additional investigations.

Natural history of carotid artery free-floating thrombus—A single center, consecutive cohort analysis

Introduction

Carotid free-floating thrombus (CFFT) is a rare cause of stroke and is thought to be associated with a high risk of recurrent cerebrovascular ischaemic events. The existing data on the natural history and optimal treatment modalities of CFFT is scanty and no clear recommendations exist.

Objective

A retrospective analysis, single-center cohort of consecutive patients diagnosed with CFFT was conducted, investigating the risk for recurrent cerebrovascular ischaemic events.

Methods

We performed a single-center retrospective analysis including all patients presenting at our tertiary center between January 2005 and December 2020 with symptoms consistent with ischaemic stroke and/or transient ischaemic attack. Digital subtraction angiography (DSA), computed tomography angiography (CTA) or magnetic resonance angiography (MRA) were used to diagnose CFFT. In all included patients, CFFT was confirmed with a second imaging modality. CFFT was defined on imaging as a defect in contrast filling extending into the carotid lumen. We gathered information on vascular risk factors, diagnosis and follow-up methods, modality of treatment and neurological outcome. A survival analysis was performed, assessing the risk for recurrent cerebrovascular events.

Results

In total, N = 62 patients presenting with symptomatic CFFT were included. Mean age was 68 years, 69% (43/62) of patients were male, 52% (32/62) current or previous smokers, 76% (47/62) suffered from arterial hypertension, 68% (42/62) from dyslipidaemia, and 31% (19/62) from diabetes mellitus. Overall, 71% (44/62) of patients received any kind of intervention [endovascular or surgical carotid thrombo-endartectomy (CEA)] at any time point during follow-up. Sixteen percent of patients (10/62) received intervention within 48 h after diagnosis of CFFT. The survival analysis and Kaplan-Meier model censoring patients at the time of intervention or last follow-up showed that the risk for any recurrent ischaemic stroke was 19.7% within the first 7 days and 27.4% within 3 months after diagnosis. No patients experienced a new ischaemic stroke beyond 11 days after diagnosis of CFTT (n = 17).

Conclusion

The risk of recurrent ischaemic events in patients with CFFT is high, especially in the first week after diagnosis. Prospective studies are needed to further investigate the optimal management of these patients.

Case report: Ultrasound-Assisted endovascular therapy for carotid artery floating thrombus

Background

Carotid free-floating thrombus (CFFT) is a rare but sometimes emergent condition. There has been controversy over the optimal treatment strategy. Emerging evidence suggests that endovascular thrombectomy (EVT) may be an alternative to surgery. Accurate alignment of the aspiration catheter and thrombus during EVT is critical but has, so far, remained unresolved.

Case summary

This is a rare case of CFFT presenting with acute right-sided facial droop and moderate dysarthria in a 77-year-old man. He was in sinus rhythm with a blood pressure of 110/82 mmHg. Both non-contrast CT (NCCT) and head CT angiography (CTA) were unremarkable, while whole-brain CT perfusion (WB-CTP) suggested left hemisphere core infarction. Delayed imaging of the left internal carotid system by 4D-CTA suggested severe proximal obstructive disease, as confirmed by carotid CTA and ultrasonography. The initial two aspirations under DSA were invalid due to the challenging anatomical angle between the thrombus and the catheter. The success of CFFT removal was achieved with a pressure-assisted ultrasound-guided approach that helps to compress the catheter tip toward the thrombus.

Conclusion

We innovatively report a successful ultrasound-guided EVT for CFFT. Ultrasound assistance can provide quick and effective guidance and may guide tailored aspirations during EVT.

The Flashlight-Sign: A Novel B-Flow Based Ultrasound Finding for Detection of Intraluminal, Wall-Adherent, Floating Structures of the Abdominal Aorta and Peripheral Arteries

This study aimed to evaluate the potential diagnostic value of a novel, sonographic, B-Flow (BFl)-based sign (“flashlight sign”, FLS) for the detection of wall-adherent, floating arterial structures (WAFAS). The FLS, characterized by a fast moving, very bright, intraluminal signal, was detected in 28 patients with WAFAS. We divided this cohort into three subgroups according to the affected vascular segments: (1) peripheral arteries (n = 10); (2) native abdominal aorta (n = 8); and (3) abdominal aorta after endovascular aortic repair (EVAR; n = 10). Clinical characteristics were analyzed and BFl-findings were compared with contrast-enhanced ultrasound (CEUS) and computed tomography angiography (CTA). Seven patients (25%) suffered from arterial embolism downstream to the FLS (EVAR, n = 4; native abdominal aorta, n = 1; peripheral arteries, n = 2). WAFAS of the abdominal aorta (native or after EVAR), as indicated by the FLS, were visible by CEUS and CTA in 60% and 93.3%, respectively. Based on the largest cohort (to this point) of patients with WAFAS, we propose a clinically useful, BFl-based sonographic sign for the detection of these underrated arterial pathologies in the abdominal aorta and the peripheral arteries.

Ischemic Stroke and Vaccine-Induced Immune Thrombotic Thrombocytopenia following COVID-19 Vaccine: A Case Report with Systematic Review of the Literature

INTRODUCTION

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a prothrombotic syndrome observed after adenoviral vector-based vaccines for severe acute respiratory syndrome coronavirus 2. It is characterized by thrombocytopenia, systemic activation of coagulation, extensive venous thrombosis, and anti-platelet factor 4 antibodies. Arterial thrombosis is less common and mainly affects the aorta, peripheral arteries, heart, and brain. Several cases of ischemic stroke have been reported in VITT, often associated with large vessel occlusion (LVO). Here, we describe a case of ischemic stroke with LVO after Ad26.COV2.S vaccine, then we systematically reviewed the published cases of ischemic stroke and VITT following COVID-19 vaccination.

METHODS

We describe a 58-year-old woman who developed a thrombotic thrombocytopenia syndrome with extensive splanchnic vein thrombosis and ischemic stroke due to right middle cerebral artery (MCA) occlusion, 13 days after receiving Ad26.COV2.S vaccination. Then, we performed a systematic review of the literature until December 3, 2021 using PubMed and EMBASE databases. The following keywords were used: ("COVID-19 vaccine") AND ("stroke"), ("COVID-19 vaccine") AND ("thrombotic thrombocytopenia"). We have selected all cases of ischemic stroke in VITT.

RESULTS

Our study included 24 patients. The majority of the patients were females (79.2%) and younger than 60 years of age (median age 45.5 years). Almost all patients (96%) received the first dose of an adenoviral vector-based vaccine. Ischemic stroke was the presenting symptom in 18 patients (75%). Splanchnic venous thrombosis was found in 10 patients, and cerebral venous thrombosis in 5 patients (21%). Most patients (87.5%) had an anterior circulation stroke, mainly involving MCA. Seventeen patients (71%) had an intracranial LVO. We found a high prevalence of large intraluminal thrombi (7 patients) and free-floating thrombus (3 patients) in extracranial vessels, such as the carotid artery, in the absence of underlying atherosclerotic disease. Acute reperfusion therapy was performed in 7 of the 17 patients with LVO (41%). One patient with a normal platelet count underwent intravenous thrombolysis with alteplase, while 6 patients underwent mechanical thrombectomy. A malignant infarct occurred in 9 patients and decompressive hemicraniectomy was performed in 7 patients. Five patients died (21%).

CONCLUSION

Our study points out that, in addition to cerebral venous thrombosis, adenoviral vector-based vaccines also appear to have a cerebral arterial thrombotic risk, and clinicians should be aware that ischemic stroke with LVO, although rare, could represent a clinical presentation of VITT.

Acute Symptomatic Free-Floating Thrombus in the Innominate Artery, a Case Series

BACKGROUND

Innominate artery embolism may result in upper extremity ischemia or stroke. A free-floating thrombus originating from the IA is an unusual and dangerous disorder with embolic potential. Only isolated cases have been described showing different treatment modalities.

PURPOSE

To present 3 cases of free-floating thrombus in the IA treated at our institution with 3 different approaches.

CASES

The first case is a patient with a free-floating thrombus in the IA treated with cervical debranching and ligation of the proximal right carotid artery; another case of a patient treated with a hybrid approach with deployment of an iliac limb in the IA plus right carotid to subclavian bypass; and a third case of a patient operated by open arch thrombectomy.

CONCLUSIONS

Free-floating thrombus in the IA is a threatening condition feasible to be managed through different customized surgical approaches in specialized centers.

Use of transcarotid artery revascularization for mechanical thrombectomy and treatment of symptomatic high-grade carotid artery stenosis associated with free-floating thrombus: illustrative case

BACKGROUND

Patients with symptomatic high-grade stenosis of the internal carotid artery (ICA) associated with a free-floating thrombus (FFT) present a significant clinical challenge. In general, for patients with moderate to severe symptomatic ICA stenosis, carotid revascularization is recommended within 2 weeks of symptom onset; however, some physicians suggest that revascularization should be delayed in cases with FFT because some data suggest that early surgery with carotid endarterectomy or carotid stent poses a higher risk for stroke. Likewise, delayed revascularization with anticoagulation may increase risk of recurrent stroke. Few reports on the management of FTT included the use of a transcarotid artery revascularization (TCAR) approach for carotid revascularization with mechanical aspiration thrombectomy.

OBSERVATIONS

This report described the use of TCAR for direct mechanical thrombectomy and carotid stent placement for a patient with 80% right ICA stenosis along with a large FFT extending into the bulb and the external carotid artery.

LESSONS

The TCAR approach for mechanical thrombectomy and carotid stenting is a safe alternative for early revascularization with low periprocedural stroke risks.

Direct Advancement of Balloon-Guide Catheter Distal to the Carotid Free-Floating Thrombus Achieves Smart Mechanical Thrombectomy

A 68-year-old man with bladder cancer developed sudden dysarthria and left hemiplegia. MRI revealed occlusion of the right middle cerebral artery (MCA). Cerebral angiography revealed a large carotid free-floating thrombus (CFFT) at the origin of the right internal carotid artery (ICA) and right M1 occlusion. A balloon-guide catheter (BGC) was directly guided distal to the CFFT. Mechanical thrombectomy (MT) was performed on the M1 occlusion while the balloon was inflated to block antegrade blood flow, and good recanalization was achieved. To continue processing the CFFT, the deflated BGC was pulled to the common carotid artery, and the thrombus dispersed into the external carotid artery (ECA). Subsequently, the patient’s symptoms improved. Directly advancing a BGC distally to a CFFT may be a useful treatment strategy for tandem lesions with carotid free-floating thrombi.

Intracranial non-occlusive intraluminal thrombus may indicate underlying etiology of large vessel occlusion in patients undergoing endovascular therapy

BACKGROUND

The underlying etiology of intracranial non-occlusive intraluminal thrombus (iNOT) remains unknown. This study aimed to investigate whether the presence of iNOT can indicate the underlying etiology of large vessel occlusion (LVO) in patients undergoing endovascular therapy (EVT).

METHODS

Among patients who underwent EVT at three comprehensive stroke centers, we included those with intracranial LVO in the anterior circulation. The presence of iNOT was determined by pretreatment DSA. We investigated the association between iNOT and intracranial atherosclerotic stenosis (ICAS) related LVO.

RESULTS

Of 546 patients, 44 (8.1%) had iNOT. Patients with iNOT were younger, had less hypertension, atrial fibrillation, and a history of antiplatelet use. In addition, the involvement of the M1 segment of the middle cerebral artery (MCA) was more frequent. However, they had a lower National Institutes of Health Stroke Scale (NIHSS) score on admission and longer onset to recanalization time compared with patients with no iNOT. In a logistic regression model adjusting for age, sex, atrial fibrillation, smoking, prior antiplatelet and anticoagulant use, intravenous tissue plasminogen activator, NIHSS on admission, number of technical trials, intraprocedural re-occlusion, and the location of LVO (p<0.10 in the univariate analysis), the presence of iNOT was significantly associated with ICAS related LVO (adjusted OR 3.04; 95% CI 1.33 to 6.90; p=0.007).

CONCLUSIONS

The presence of iNOT may reflect an underlying ICAS related LVO in patients undergoing EVT.

Management of Free-Floating Thrombus in the Vertebral Artery in a Middle-Aged Smoker with Secondary Polycythemia Vera

Free-floating thrombus (FFT) of the cervicocranial arteries is a rare neurovascular condition. Up to now, there is no standardized definition for FFT. Therefore, FFT is occasionally mistaken for intraluminal thrombus (ILT) or smooth mural thrombus. The most precise and ideal definition of FFT would be a long-extended intraarterial thrombus that is attached to the arterial wall with its one end, while its other end is surrounded by blood flow and moves freely with the cardiac cycle. FFT usually manifests as an ischemic stroke, thus it is considered as an emergency case. Herein, we report a rare case of symptomatic FFT in the left vertebral artery extending from V0 to V2 segments in a middle-aged smoker, who presented with multiple embolic strokes in different territories of posterior circulation and was successfully treated medically. This case sheds light on the challenges of the clinical approach of FFT in the vertebral artery and it is an attempt to draw attention to the necessity of conducting a large-scale study to find out the ideal approach to manage such conditions.

Differentiating Carotid Free-Floating Thrombus From Atheromatous Plaque Using Intraluminal Filling Defect Length on CTA: A Validation Study

OBJECTIVE

To validate a previously proposed filling defect length threshold of >3.8 mm on CT angiography (CTA) to discriminate between free-floating thrombus (FFT) and plaque of atheroma.

METHODS

This was a prospective multicenter observational study of 100 participants presenting with TIA/stroke symptoms and a carotid intraluminal filling defect on initial CTA. Follow-up CTA was obtained within 1 week and at weeks 2 and 4 if the intraluminal filling defect was unchanged in length. Resolution or decreased length was diagnostic of FFT, whereas its static appearance after 4 weeks was indicative of plaque. Diagnostic accuracy of FFT length was assessed by receiver operating characteristic analysis.

RESULTS

Ninety-five participants (mean [SD] age 68 [13] years, 61 men, 83 participants with FFT, 12 participants with a plaque) were evaluated. The >3.8-mm threshold had a sensitivity of 88% (73 of 83) (95% confidence interval [CI] 78%-94%) and specificity of 83% (10 of 12) (95% CI 51%-97%) (area under the curve 0.91, p < 0.001) for the diagnosis of FFT. The optimal length threshold was >3.64 mm with a sensitivity of 89% (74 of 83) (95% CI 80%-95%) and specificity of 83% (10 of 12) (95% CI 51%-97%). Adjusted logistic regression showed that every 1-mm increase in intraluminal filling defect length is associated with an increase in odds of FFT of 4.6 (95% CI 1.9-11.1, p = 0.01).

CONCLUSION

CTA enables accurate differentiation of FFT vs plaque using craniocaudal length thresholds.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02405845.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in patients with TIA/stroke symptoms, the presence of CTA-identified filling defects of lengths >3.8 mm accurately discriminates FFT from atheromatous plaque.

A Case of Internal Carotid Artery Occlusion Caused by En Bloc Distal Embolization of Carotid Free-Floating Thrombus Treated by Mechanical Thrombectomy

Objective

We report a case of internal carotid artery (ICA) occlusion caused by en bloc distal embolization of carotid free-floating thrombus (FFT) treated by mechanical thrombectomy.

Case Presentation

A 57-year-old woman was brought to our hospital with dysarthria, right hemiparesis, and motor aphasia. MRI and MRA revealed acute infarction due to middle cerebral artery occlusion. Carotid ultrasonography demonstrated a pedunculated mobile plaque in the left ICA. We diagnosed embolic infarction due to the carotid FFT and started medical treatment. However, on the second hospital day, the carotid FFT detached from the arterial wall en bloc, resulting in left ICA occlusion. The occluded ICA was successfully recanalized by mechanical thrombectomy.

Conclusion

FFT is associated with a high risk of embolic ischemic stroke and the primary treatment strategy must be carefully considered.

Imaging of nonatheromatous carotid artery disease

Imaging diagnosis of nonatheromatous carotid artery disease is challenging due to its low prevalence in contrast to that of atheromatous disease. Congenital anomalies are frequently discovered incidentally, as the chronicity of these conditions allows for compensatory flow development. The inflammatory conditions typically present with nonspecific courses, and a high clinical suspicion along with timely imaging evaluation can guide the diagnosis. Carotid dissection is the result of a partial disruption of the arterial wall and can be seen in previously healthy patients, in patients with underlying noninflammatory arteriopathies or trauma. Traumatic injuries to the carotid artery may occur under many different conditions and mechanisms and timely recognition of high-risk patients improves patient outcomes. Although free-floating thrombi (FFT) formation is typically seen with atherosclerotic plaque rupture, different conditions may also predispose to FFT. In this review article, we study the different imaging features of nonatheromatous carotid artery disease using ultrasonography, computed tomography angiography, magnetic resonance angiography, and digital subtraction angiogram.

Symptomatic Common Carotid Free-Floating Thrombus in a COVID-19 Patient, Case Report and Literature Review

Carotid free-floating thrombus is an uncommon entity that usually presents with neurologic symptoms. Crescendo transient ischemic attack is an accepted indication for urgent carotid endarterectomy. COVID-19 is associated with severe thromboembolic complications. We report the case of a 61-year-old man who developed, 2 weeks after the diagnosis of COVID-19, crescendo transient ischemic attack, complicating a large intraluminal floating thrombus within the right common carotid artery. A carotid thromboendarterectomy under local anesthesia, with patch closure was immediately performed without complications. We conducted a literature review to identify cases of common carotid artery thrombus related to COVID-19. Carotid free-floating thrombus in the common carotid artery is exceptional. However, since the beginning of the COVID-19 pandemic, 15 cases have been published.

Intraluminal Thrombus and Outcomes of Patients With Acute Large Vessel Occlusive Stroke Undergoing Endovascular Treatment

BACKGROUND AND PURPOSE

Intraluminal thrombus (ILT) is an emerging imaging marker in acute ischemic stroke. We aimed to investigate the association of ILT with outcomes of acute large vessel occlusion (LVO) patients receiving endovascular treatment.

METHODS

Acute LVO stroke patients who underwent endovascular treatment within 24 hours, in a prospective, nationwide registry were enrolled. Pretreatment digital subtraction angiography was reviewed for the presence of ILT. The primary outcome was 90-day functional dependence (modified Rankin Scale scores, 3-6). Secondary outcomes included 24-hour LVO, 90-day death, and symptomatic intracranial hemorrhage.

RESULTS

Among 711 patients enrolled, 75 (10.5%) with ILT were less likely to have 90-day functional dependence compared with those without ILT (adjusted odds ratio, 0.53 [95% CI, 0.31-0.90]; P=0.021). The same trend was found among those with successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b-3; P=0.008) but not in those without successful reperfusion (P=0.107). Presence of ILT was also independently associated with a lower rate of 24-hour LVO (adjusted odds ratio 0.34 [95% CI, 0.13-0.89]; P=0.028). However, those with or without ILT had similar risks of symptomatic intracranial hemorrhage and 90-day death.

CONCLUSIONS

Among acute LVO patients receiving endovascular treatment, pretreatment ILT-positive patients may have a better 90-day functional outcome (versus ILT-negative) but similar risk of death and symptomatic intracranial hemorrhage. The possibly favorable effect of ILT patients remained in those with successful reperfusion. Registration: URL: http://www.chictr.org.cn; Unique identifier: ChiCTR1900022154.

Huge Free-Floating Thrombus in the Internal Carotid Artery Under Duplex Ultrasound Surveillance

Carotid free-floating thrombus (FFT) is an unusual finding in acute ischemic stroke. Atherosclerosis is the most common etiology of FFT formation.

Free-Floating Thrombus in the Distal Internal Carotid Artery Causing a Stroke

We present a patient suffering from a stroke with a free-floating thrombus extending up to the distal internal carotid artery. The thrombus was totally resolved after a 2-week anticoagulation regimen without leaving behind any severe residual stenosis in the carotid bulb. The optimal treatment of this rare condition remains uncertain. We report some important treatment strategies that have been used in the literature, emphasizing the anticoagulation as the mainstay of therapy. Immediate surgical and interventional manipulations carry the risk of thrombus dislodgement and embolization and should be considered if there are recurrent symptoms despite medical management.

Clinical implications of the incidental finding of a free-floating thrombus in the internal carotid artery

We present an 81-year old male in whom a routine carotid artery ultrasonographic follow-up examination incidentally revealed a large, free-floating thrombus (FFT) of the right internal carotid artery. This case focuses on the clinical decision-making regarding FFTs, which constitute a rare condition lacking a diagnostic gold standard with few available data concerning optimum treatment and natural course-in particular regarding patients in whom FFT is an incidental finding. We were able to demonstrate the accuracy of carotid artery ultrasonography in the detection as well as follow-up of FFT. Of clinical interest is furtherly a possible partial disappearance by spontaneous re-adhesion or resolution of the FFT.

A Case of Coincidental Free Floating Thrombus in the Vertebral Artery in a Patient Presenting with an Anterior Circulation Stroke and Literature Review

Free-floating thrombus (FFT) is a rare condition with unknown etiology as described by many case reports presented in previous literature. The patients usually present symptomatically while the other few patients remain asymptomatic and are usually discovered incidentally on computed tomography angiography (CTA). Most of the cases reported in the literature are of FFT in the internal carotid artery. We present a 59-year-old female as a case of FFT in the vertebral artery which was coincidently discovered on CTA in a patient initially presenting with an anterior circulation stroke. This case highlights the importance of early contrast-based vascular imaging in patients presenting with large vessel strokes that are cardioembolic in nature and the unique utilization of a direct aspiration first pass technique (ADAPT) for revascularization. Included herein an extensive review of the literature about the decision making in patients with FFT and a devised proposed practical approach to this entity.

Carotid Free-Floating Thrombus in a Stent 6 Months After Carotid Artery Stenting

BACKGROUND

Carotid free-floating thrombus (CFFT) is defined as a blood clot attached to the arterial wall with surrounding blood flow at its distal component. Although rare, it is a clinically significant cause of embolic stroke. CFFT within a stent has not been previously reported.

CASE DESCRIPTION

We report a 64-year-old man who underwent carotid artery stenting for asymptomatic right carotid artery stenosis. Six months after carotid artery stenting, he was admitted to the emergency department 1 hour after onset of left hemiparesis and dysarthria. His National Institutes of Health Stroke Scale score was 10. His medical history was notable for hypertension, chronic renal insufficiency, and type 2 diabetes mellitus. Carotid ultrasonography showed a dumbbell-shaped CFFT attached to the carotid stent that was moving in synchrony with his heartbeat. CFFT removal was performed via an endovascular approach with manual suction using a Luer Lock syringe. The CFFT was completely removed without residual stenosis. Histologic examination suggested plaque rupture associated with a lipid-rich necrotic core.

CONCLUSIONS

Carotid plaque formation and plaque rupture can occur within a carotid stent and present as a CFFT.

Surgical Thromboendarterectomy for Free-Floating Thrombus Associated with Cervical Carotid Artery Dissection: A Case Report

BACKGROUND

Free-floating thrombus (FFT) of the cervical carotid artery is a rare but critical condition leading to stroke. The most common underlying pathology is atherosclerotic plaque; nonatherosclerotic pathologies are much rarer. Here we report a case of FFT associated with cervical carotid artery dissection that was successfully treated by surgical thromboendarterectomy.

METHODS

A 51-year-old man presented with headache, pain in the left neck, and amaurosis fugax. Magnetic resonance angiography revealed mild stenosis in the bifurcation of the left carotid artery. The stenotic lesion was considered as a possible dissection because of the normal appearance of the vessel 2 years ago and its clinical presentation. Oral aspirin was initiated with the diagnosis of transient ischemic attack. Two weeks later, ultrasound was planned for further examination, which demonstrated a massive FFT with intramural hematoma in the lesion. Because FFT was present despite taking aspirin, surgical thromboendarterectomy was performed to prevent further ischemic events.

RESULTS

Intraoperative findings revealed that FFT was the thrombus protruding from the intramural hematoma caused by arterial dissection. After the whole dissected layer was removed, the residual lumen was reinforced by multiple tacking sutures to prevent recurrence of dissection. No further ischemic events and recurrence occurred during the 1-year of follow-up after the surgery.

CONCLUSIONS

When managing patients with carotid artery dissection, the formation of FFT should be considered as a possible critical feature. Surgical thromboendarterectomy with intimal tacking sutures might be an option for the treatment, ensuring immediate, preventive effects against the risk of cerebral embolism.

Carotid Stenting as Definitive Treatment for Free Floating Thrombus-Review of 7 Cases

Background and Purpose

Free floating thrombus (FFT) is a rare condition. The optimal treatment strategy is yet to be determined although medical management with anticoagulation is the mainstay. This article reports experience of treating FFT with carotid stenting.

Methods

A retrospective analysis of a prospectively maintained database was performed to identify all patients with FFT treated with carotid stenting. For each patient the demographic data, clinical presentation, location of the thrombus, type of stent and use of adjunctive devices, e.g. balloon guide catheters, clinical and radiological follow-up information as well as complications were recorded.

Results

A total of 7 patients, 4 female, with mean age of 55.6 ± 14.5 years were identified. The median National Institutes of Health Stroke Scale (NIHSS) was 7 (range 0–13) at presentation. Free floating thrombus was seen on the left in the majority of cases (n = 6, 85.7%). None of the patients had intracranial large vessel occlusion. The FFT was located in the CCA in 2 cases (28.6%) and the proximal ICA in the remaining 5 cases (71.4%). The Wallstent was used in 5 patients and a cGuard stent used in 2 patients. In 1 patient 2 overlapping stents were used but a single stent was used in the remaining patients. In 6 cases a distal filter wire was used and in 2 cases a balloon guide catheter was used as embolic protection. There were no intraoperative complications and no cases of distal clot migration or intracranial large vessel occlusion during the procedure. At last follow-up (n = 7) 6 patients were recorded as modified Rankin Scale (mRS) ≤2 and 1 patient was mRS 3.

Conclusion

Free floating thrombus of the carotid arteries can be managed with stenting.