Endovascular clot removal in small and tortuous arteries: a case series.

Acute limb ischemia (ALI) due to arterial thromboembolic occlusion is a critical emergency in vascular medicine, requiring attention for rapid diagnosis and intervention, to prevent limb loss and major amputation, which is associated with patient disability in the long term. Traditionally, surgical embolectomy has been used for the treatment of ALI. Endovascular treatment of ALI traditionally involved catheter-directed thrombolysis. This option, however, poses some limitations, including an increased risk for access site and systemic bleeding complications, especially in patients with high bleeding risk. Therefore, in the last decades, several devices have been developed and tested for the mechanical endovascular treatment of ALI. Such devices involve either rotational thrombectomy or continuous thrombus aspiration. While rotational thrombectomy is limited in rather large arteries due to the risk of dissection and perforation in arteries <3 mm, continuous thrombus aspiration can be applied in smaller vessels and tortuous anatomies. In our case series we present a minimal-invasive endovascular approach for the treatment of two patients with ALI due to thrombotic occlusion of tortious and small diameter arteries. Minimal-invasive mechanical thrombectomy using the Penumbra Aspiration System emerged as a successful alternative to surgical embolectomy, enabling prompt treatment and with a short hospital stay for both patients. Our article therefore highlights the use of continuous thrombus aspiration in small diameter vessels and tortuous anatomies, which may represent a contraindication for the use of rotational thrombectomy. In addition, this technique may be applied even in patients with higher bleeding risk since additional lysis is not necessary in patients, where complete thrombus removal can be achieved by this device.

The 100 highest-cited original articles in large vessel occlusions: A bibliometric analysis.

BACKGROUND: Large vessel occlusions (LVO) are a common etiology of morbidity and mortality. The current literature lacks a synthesis of the landscape and trends in research. OBJECTIVE: We aimed to conduct a bibliometric analysis of the 100 most cited original articles on LVOs to assess the current state of research. METHODS: Scopus database was queried from inception to December 2022 to identify the most cited original articles from 4506 retrieved records on LVOs. Publication year, country of origin, total and average annual citation count, and type of study were collected for each article. The journal impact factor (JIF) was obtained from the Journal Citation Reports database. RESULTS: The articles were published between 1994 and 2021, with most (n = 82) published during the 2011-2020 decade. The median total citation count was 108.5, with an interquartile range (IQR) of 81-149.5. The median (IQR) average annual citation count was 15.9 (11.5-22.9). Half of the articles were published in Stroke (n = 35) and Journal of NeuroInterventional Surgery (n = 15), with JIFs ranging from 1.8 to 202.7. The USA was the leading country in contributing to LVO research (n = 45). Most studies focused on the treatment (n = 63) and diagnosis (n = 22) of LVOs. CONCLUSIONS: Most articles were published during the past decade, highlighting the impact of the clinical trials of endovascular treatment on the discipline. With several ongoing clinical trials on the horizon, continued growth of the field is anticipated in the upcoming decades.

A technique for prevention of posterior stroke during urgent revascularization of an acutely ischemic left upper extremity.

Upper extremity acute limb ischemia (ALI) owing to obstruction proximal to the vertebral artery poses the risk of posterior stroke during intervention. We describe a case of upper extremity ALI secondary to thrombosis of the proximal left subclavian artery with thromboembolic occlusion at the brachial bifurcation. The patient underwent a hybrid procedure of open thromboembolectomy with endovascular vertebral artery embolic protection. The patient's distal pulses and upper extremity function returned to baseline, without evidence of posterior stroke. A literature review revealed limited reports of the use of cerebral embolic protection in the setting of emergent thromboembolectomy for upper extremity ALI.

Body position and cuff size influence lower limb arterial occlusion pressure and its predictors: implications for standardizing the pressure applied in training with blood flow restriction.

Background: Arterial occlusion pressure (AOP) is a relevant measurement for individualized prescription of exercise with blood flow restriction (BFRE). Therefore, it is important to consider factors that may influence this measure. Purpose: This study aimed to compare lower limb AOP (LL-AOP) measured with 11 cm (medium) and 18 cm (large) cuffs, in different body positions, and explore the predictors for each of the LL-AOP measurements performed. This information may be useful for future studies that seek to develop approaches to improve the standardization of pressure adopted in BFRE, including proposals for equations to estimate LL-AOP. Methods: This is a cross-sectional study. Fifty-one healthy volunteers (males, n = 25, females, n = 26; Age: 18-40 years old) underwent measurement of thigh circumference (TC), brachial blood pressure, followed by assessments of LL-AOP with medium and large cuffs in positions supine, sitting and standing positions. Results: The large cuff required less external pressure (mmHg) to elicit arterial occlusion in all three-body positions when compared to the medium cuff (p < 0.001). The LL-AOP was significantly lower in the supine position, regardless of the cuff used (p < 0.001). Systolic blood pressure was the main predictor of LL-AOP in the large cuff, while TC was the main predictor of LL-AOP with the medium cuff. Body position influenced strength of the LL-AOP predictors. Conclusion: Our results indicate that LL-AOP and its predictors are substantially influenced by body position and cuff width. Therefore, these variables should be considered when standardizing the pressure prescribed in BFRE.

Validity and reliability of a wearable blood flow restriction training device for arterial occlusion pressure assessment.

Purpose: The blood flow restriction (BFR) training is an effective approach to promoting muscle strength, muscle hypertrophy, and regulating the peripheral vascular system. It is recommended to use to the percentage of individual arterial occlusion pressure (AOP) to ensure safety and effectiveness. The gold standard method for assessing arterial occlusive disease is typically measured using Doppler ultrasound. However, its high cost and limited accessibility restrict its use in clinical and practical applications. A novel wearable BFR training device (Airbands) with automatic AOP assessment provides an alternative solution. This study aims to examine the reliability and validity of the wearable BFR training device. Methods: Ninety-two participants (46 female and 46 male) were recruited for this study. Participants were positioned in the supine position with the wearable BFR training device placed on the proximal portion of the right thigh. AOP was measured automatically by the software program and manually by gradually increasing the pressure until the pulse was no longer detected by color Doppler ultrasound, respectively. Validity, inter-rater reliability, and test-retest reliability were assessed by intraclass correlation coefficients (ICC) and Bland-Altman analysis. Results: The wearable BFR training device demonstrated good validity (ICC = 0.85, mean difference = 4.1 ± 13.8 mmHg [95% CI: -23.0 to 31.2]), excellent inter-rater reliability (ICC = 0.97, mean difference = -1.4 ± 6.7 mmHg [95% CI: -14.4 to 11.7]), and excellent test-retest reliability (ICC = 0.94, mean difference = 0.6 ± 8.6 mmHg [95% CI: -16.3 to 17.5]) for the assessment of AOP. These results were robust in both male and female subgroups. Conclusion: The wearable BFR training device can be used as a valid and reliable tool to assess the AOP of the lower limb in the supine position during BFR training.

Actualización en el manejo de la isquemia mesentérica aguda

La isquemia mesentérica aguda (IMA) es una emergencia médico-quirúrgica poco frecuente con alta morbimortalidad. Corresponde a una interrupción brusca del aporte sanguíneo a un segmento del intestino, produciendo isquemia, daño celular, necrosis intestinal y eventualmente la muerte. La principal etiología de este cuadro es la oclusión arterial de tipo embólica, seguida por la trombótica, no oclusiva y trombótica venosa. Es una patología infrecuente con una incidencia baja, de 12 por 100.000 habitantes en series internacionales. Su principal síntoma es el dolor abdominal tipo cólico de comienzo brusco, vómitos y diarrea, esta última sucediendo posteriormente. En el examen físico se pueden constatar signos de shock y distensión abdominal. Ante la sospecha, los pacientes hemodinámicamente inestables deben ser llevados urgentemente a laparotomía exploradora, y en aquellos estables, se debe solicitar un Angio-TC para confirmar el diagnóstico y planificar el tratamiento. Existen dos métodos para tratar esta patología: la cirugía abierta y la cirugía endovascular o mínimamente invasiva. Finalmente, con el avance de estos nuevos métodos, la tasa de mortalidad ha disminuido, significativamente, en la última década.

Acute mesenteric ischemia (AMI) is a rare medical-surgical emergency that must be treated early due to its high morbidity and mortality. It corresponds to a sudden interruption of the blood supply to a segment of the intestine, producing ischemia, cell damage, intestinal necrosis and eventually death if it is not treated. The main etiology of this condition is embolic-type arterial occlusion, followed by thrombotic, nonocclusive, and venous thrombotic. It is an infrequent pathology with a low incidence of 12 per 100,000 inhabitants in international series. During the information collection, no data was found on the Chilean population since before 1983. Its main symptom is colicky abdominal pain with a sudden onset, vomiting and diarrhea that begins after the pain. On physical examination, signs of shock and abdominal distention may be noted. Hemodynamically unstable patients should be urgently taken to exploratory laparotomy as soon as the condition is suspected, and in stable patients, an angio-CT should be requested to confirm the diagnosis and plan treatment. There are two methods to treat this pathology, open surgery and endovascular or minimally invasive surgery. The form of therapy depends on the preoperative or intraoperative findings and the type of etiology. Finally, with the advancement of these new methods, the mortality rate has decreased in the last decade.

Prognostic factors and clinical features of rhino-orbital-mucormycosis cases: an update for patient and visual survivals.

AIM: To determine the frequency of patients' vision survival and prognostic factors and evaluate clinical features in rhino-orbital mucormycosis. METHODS: Forty-three eyes of 43 patients followed up with orbital mucormycosis infections were included in the study. Demographic characteristics of the patients, symptoms at admission, ophthalmologic and non-ophthalmologic examination findings, clinical findings during follow-up, medical and surgical procedures, and complications were recorded. Patient survival was determined by assessing the incidence of mortality, and vision survival was defined as achieving a final visual acuity of at least light perception. RESULTS: Twenty-seven (62.8%) patients were male, and 16 (37.2%) were female. When the underlying disease status of the patients was examined, it was observed that all patients had an underlying disease and diabetes constituted the majority (65.2%). Periorbital swelling (69.8%) and ophthalmoplegia (53.5%) were the most common symptoms and findings at the admission of patients with mucormycosis infection. The disease resulted in death in 22 (51.2%) patients. The presence of fever and shorter duration of antifungal therapy were associated with lower patient survival. Exenteration surgery was not found to be associated with the survival of the patients. Frozen eye, loss of pupillary light reflex, and development of central retinal artery occlusion were associated with lower vision survival. CONCLUSION: This study presents one of the most extensive patient series in the literature on rhino-orbital mucormycosis. Knowing the patients' symptoms at the time of admission and the clinical findings during the infection process will increase awareness about the disease.

Diagnostic and therapeutic complexity of Susac syndrome.

A 40-year-old man who attended the emergency department with a scotoma in right eye. He mentioned hearing difficulties and headache for months and he had sensory and motor deficits in the previous days. In the ophthalmic examination, the right eye had areas of arterial occlusion. MRI revealed hyperintense lesions. The patient was diagnosed with Susac syndrome. He was treated with systemic steroids, however, it was not enough to control the condition. Rituximab and intravenous immunoglobulins were added, which allowed the improvement of neurological symptoms, but the alteration of the visual field and the hearing defect did not recover. Early diagnosis of this pathology is essential, since delaying treatment can cause irreversible consequences. Sometimes it is difficult given the wide variety of symptoms and the course of the disease. Ocular manifestations may raise suspicion when the general symptoms are nonspecific.

Comprehensive management of challenging recurrent aortoiliac and lower extremity occlusive disease with simultaneous modified-covered endovascular reconstruction of the aortic bifurcation, inferior mesenteric artery snorkel, and lower extremity bypass.

OBJECTIVES: Despite recent advancements in endovascular technology and proven durability of open surgeries, managing extensive aortoiliac occlusive disease (AIOD) with concurrent severe lower extremity (LE) arterial occlusion remains a formidable challenge. This paper introduces a comprehensive approach to addressing recurrent AIOD and LE occlusive diseases by employing modified-CERAB, inferior mesenteric artery (IMA) snorkel, and LE bypass in a challenging case. METHODS: A 56-year-old male patient presented with subacute bilateral lower extremity rest pain with dry gangrene in the left great toe and a complex medical history. His history included a hostile abdomen stemming from past ischemic bowel episodes and multiple bowel resections through laparotomies. Furthermore, the patient had a persistent left ventricular thrombus (LVT), stage-2 chronic kidney disease (CKD), diabetes, and was currently experiencing bilateral LE rest pain and dry gangrene in the left great toe, accompanied by severe dermatitis in both LEs. RESULTS: He successfully underwent modified-CERAB with a concurrent snorkel technique for IMA preservation, along with an LE bypass to resolve bilateral LE critical ischemia. CONCLUSION: This comprehensive management approach, combining simultaneous modified-CERAB, IMA snorkel, and LE bypass, provides an effective alternative for addressing complex AIOD and LE occlusive disease patients with hostile abdomen.

Case report: Susac syndrome-two ends of the spectrum, single center case reports and review of the literature.

Susac syndrome is a rare and enigmatic complex neurological disorder primarily affecting small blood vessels in the brain, retina, and inner ear. Diagnosing Susac syndrome may be extremely challenging not only due to its rarity, but also due to the variability of its clinical presentation. This paper describes two vastly different cases-one with mild symptoms and good response to therapy, the other with severe, complicated course, relapses and long-term sequelae despite multiple therapeutic interventions. Building upon the available guidelines, we highlight the utility of black blood MRI in this disease and provide a comprehensive review of available clinical experience in clinical presentation, diagnosis and therapy of this disease. Despite its rarity, the awareness of Susac syndrome may be of uttermost importance since it ultimately is a treatable condition. If diagnosed in a timely manner, early intervention can substantially improve the outcomes of our patients.

Fournier's gangrene revealing an acute arterial occlusion: A case report.

INTRODUCTION AND IMPORTANCE: Fournier gangrene (FG) is a rare form of necrotizing fasciitis that affects both the deep and superficial layers of the perineal genital region. When left untreated, Fournier gangrene can rapidly advance, leading to substantial morbidity and mortality. Herein, we present a case of Fournier's gangrene, which revealed acute arterial occlusion. To the best of our knowledge, few cases of Fournier's gangrene secondary to arterial occlusion have been reported. CASE PRESENTATION: We report the case of a 37-year-old man with no known medical history who presented with fever and painful swelling of the scrotum. Physical examination revealed a large black spot on the scrotum surrounded by erythema, suggestive of Fournier's gangrene. We performed an extended debridement of the scrotal area. Three days later, the patient complained of severe pain in the left foot accompanied by numbness. Lower limb computed tomographic angiography (CTA) revealed multiple arterial occlusions. Thrombectomy and anticoagulation therapy were crucial in managing the vascular thrombosis and preventing the further extension of the gangrene. CLINICAL DISCUSSION: This case underscores the importance of recognizing diverse etiologies of Fournier's gangrene, including vascular involvement, and emphasizes the need for a multidisciplinary approach. Early identification, aggressive surgical debridement, and broad-spectrum antibiotics remain the cornerstone of management, with the added consideration of anticoagulation in cases involving vascular thrombosis. CONCLUSION: FG is a rare yet potentially life-threatening condition. Its multifaceted etiologies, including vascular factors, underscore the complexity of its presentation and challenges for timely diagnosis. The recognition of vascular involvement as a potential etiology of FG warrants further in-depth exploration.

Blood flow restriction pressure for narrow cuffs (5 cm) cannot be estimated with precision.

Blood flow restriction pressures are set relative to the lowest pressure needed to occlude blood flow with that specific cuff. Due to pressure limitations of some devices, it is often not possible to occlude blood flow in all subjects and apply a known relative pressure in the lower body with a 5 cm wide cuff.Objective. To use a device capable of generating high pressures (up to 907 mmHg) to create and validate an estimation equation for the 5 cm cuff in the lower body using a 12 cm cuff.Approach. 170 participants had their arterial occlusion pressure (AOP) with a 5 cm and 12 cm cuff and their thigh circumference measured in their right leg. The sample was randomly allocated to a prediction group (66%) and validation group (33%). Thigh circumference and 12 cm AOP were used as predictors. A Bland-Altman plot was constructed to assess agreement between measured and predicted values.Main results. The mean difference (95% confidence interval) between the observed (336.8 mmHg) and the predicted (343.9 mmHg) 5 cm AOP was 7.1 (-11.9, 26.1) mmHg. The 95% limits of agreement were -133.6 to 147.8 mmHg. There was a negative relationship between the difference and the average of predicted and measured 5 cm AOP (B= -0.317,p= 0.000043).Significance. Although this was the first study to quantify AOP over 600 mmHg with a 5 cm cuff, our equation is not valid across all levels of pressure. If possible, larger cuff widths should be employed in the lower body.

Modeling cerebrovascular responses to assess the impact of the collateral circulation following middle cerebral artery occlusion.

OBJECTIVE: An improved understanding of the role of the leptomeningeal collateral circulation in blood flow compensation following middle cerebral artery (MCA) occlusion can contribute to more effective treatment development for ischemic stroke. The present study introduces a model of the cerebral circulation to predict cerebral blood flow and tissue oxygenation following MCA occlusion. METHODS: The model incorporates flow regulation mechanisms based on changes in pressure, shear stress, and metabolic demand. Oxygen saturation in cerebral vessels and tissue is calculated using a Krogh cylinder model. The model is used to assess the effects of changes in oxygen demand and arterial pressure on cerebral blood flow and oxygenation after MCA occlusion. RESULTS: An increase from five to 11 leptomeningeal collateral vessels was shown to increase the oxygen saturation in the region distal to the occlusion by nearly 100%. Post-occlusion, the model also predicted a loss of autoregulation and a decrease in flow to the ischemic territory as oxygen demand was increased; these results were consistent with data from experiments that induced cerebral ischemia. CONCLUSIONS: This study highlights the importance of leptomeningeal collaterals following MCA occlusion and reinforces the idea that lower oxygen demand and higher arterial pressure improve conditions of flow and oxygenation.

[Modern biochemical markers of acute mesenteric ischemia]. / Sovremennye biokhimicheskie markery ostroi mezenterial'noi ishemii.

OBJECTIVE: To analyze modern literature data on biochemical markers of critical mesenteric ischemia. MATERIAL AND METHODS: We analyzed the most promising, highly specific and sensitive biochemical markers of total and segmental intestinal damage following acute mesenteric ischemia. Analysis included domestic and foreign literature data between 2015 and 2023. RESULTS: We identified the most easy-to-use for any hospitals biochemical markers with at least 90% sensitivity and specificity for further practical research. CONCLUSION: Further prospective research will provide a new step in solving the problem of timely diagnosis of acute mesenteric circulatory disorders.

A systematic review of the relationship between muscle oxygen dynamics and energy rich phosphates. Can NIRS help?

BACKGROUND: Phosphocreatine dynamics provide the gold standard evaluation of in-vivo mitochondrial function and is tightly coupled with oxygen availability. Low mitochondrial oxidative capacity has been associated with health issues and low exercise performance. METHODS: To evaluate the relationship between near-infrared spectroscopy-based muscle oxygen dynamics and magnetic resonance spectroscopy-based energy-rich phosphates, a systematic review of the literature related to muscle oxygen dynamics and energy-rich phosphates was conducted. PRISMA guidelines were followed to perform a comprehensive and systematic search of four databases on 02-11-2021 (PubMed, MEDLINE, Scopus and Web of Science). Beforehand pre-registration with the Open Science Framework was performed. Studies had to include healthy humans aged 18-55, measures related to NIRS-based muscle oxygen measures in combination with energy-rich phosphates. Exclusion criteria were clinical populations, laboratory animals, acutely injured subjects, data that only assessed oxygen dynamics or energy-rich phosphates, or grey literature. The Effective Public Health Practice Project Quality Assessment Tool was used to assess methodological quality, and data extraction was presented in a table. RESULTS: Out of 1483 records, 28 were eligible. All included studies were rated moderate. The studies suggest muscle oxygen dynamics could indicate energy-rich phosphates under appropriate protocol settings. CONCLUSION: Arterial occlusion and exercise intensity might be important factors to control if NIRS application should be used to examine energetics. However, more research needs to be conducted without arterial occlusion and with high-intensity exercises to support the applicability of NIRS and provide an agreement level in the concurrent course of muscle oxygen kinetics and muscle energetics. TRIAL REGISTRATION: https://osf.io/py32n/ . KEY POINTS: 1. NIRS derived measures of muscle oxygenation agree with gold-standard measures of high energy phosphates when assessed in an appropriate protocol setting. 2. At rest when applying the AO protocol, in the absence of muscle activity, an initial disjunction between the NIRS signal and high energy phosphates can been seen, suggesting a cascading relationship. 3. During exercise and recovery a disruption of oxygen delivery is required to provide the appropriate setting for evaluation through either an AO protocol or high intensity contractions.

Monocular Painless Vision Loss in the Emergency Department: Multipurpose Utility of Point-of-Care Ultrasound.

BACKGROUND: Eye-related symptoms are a common presentation in the emergency department (ED). The cases range from simple viral conjunctivitis to trauma-related eye injuries. One pathological condition that could lead to vision loss is retinal artery occlusion (RAO). Evaluating a patient with an eye symptom requires thorough eye examination and advanced imaging in certain instances. Consultation with an ophthalmologist is also necessary for cases that require treatment recommendations and further testing. In the ED, point-of-care ultrasound (POCUS) is a commonly used diagnostic tool that can be used for ocular examination. CASE REPORT: We reported a case of a 60-year-old man who presented with painless partial right-eye vision loss. POCUS showed decreased flow in the right central retinal artery with an area of the pale retina seen on the image from the retinal camera, suggesting a possible branch RAO. Further examination with POCUS showed plaque formation at the carotid bifurcation, a potential cause of the patient's symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians and other providers should be encouraged to use POCUS to diagnose eye symptoms accurately and promptly. Abnormal findings will prompt immediate specialty consult and early appropriate management. Our case and other reported cases highlight POCUS's reliability and rapid diagnostic ability.

N-Acetyl Cysteine Prevents Arterial Thrombosis in a Dose-Dependent Manner In Vitro and in Mice.

BACKGROUND: Platelet-rich thrombi occlude arteries causing fatal infarcts like heart attacks and strokes. Prevention of thrombi by current antiplatelet agents can cause major bleeding. Instead, we propose using N-acetyl cysteine (NAC) to act against the protein VWF (von Willebrand factor), and not platelets, to prevent arterial thrombi from forming. METHODS: NAC was assessed for its ability to prevent arterial thrombosis by measuring platelet accumulation rate and occlusion time using a microfluidic model of arterial thrombosis with human blood. Acute clot formation, clot stability, and tail bleeding were measured in vivo with the murine modified Folts model. The effect of NAC in the murine model after 6 hours was also measured to determine any persistent effects of NAC after it has been cleared from the blood. RESULTS: We demonstrate reduction of thrombi formation following treatment with NAC in vitro and in vivo. Human whole blood treated with 3 or 5 mmol/L NAC showed delayed thrombus formation 2.0× and 3.7× longer than control, respectively (P<0.001). Blood treated with 10 mmol/L NAC did not form an occlusive clot, and no macroscopic platelet aggregation was visible (P<0.001). In vivo, a 400-mg/kg dose of NAC prevented occlusive clots from forming in mice without significantly affecting tail bleeding times. A lower dose of NAC significantly reduced clot stability. Mice given multiple injections showed that NAC has a lasting and cumulative effect on clot stability, even after being cleared from the blood (P<0.001). CONCLUSIONS: Both preclinical models demonstrate that NAC prevents thrombus formation in a dose-dependent manner without significantly affecting bleeding time. This work highlights a new pathway for preventing arterial thrombosis, different from antiplatelet agents, using an amino acid derivative as an antithrombotic therapeutic.

In young patients with stroke of undetermined etiology, large vessel occlusions are less frequent in the group with high-risk patent foramen ovale.

INTRODUCTION: Patent foramen ovale (PFO) is present in a significant proportion of young patients with stroke of undetermined etiology, but is not always causal. Therefore, classifications (RoPE, PASCAL) have been developed to determine the probability that PFO is the stroke cause. However, the presence of an initial arterial occlusion as a prediction factor was not studied when these classifications were built. Our aim was to evaluate the presence of arterial occlusion in young patients with stroke of undetermined etiology with/without high-risk PFO. METHODS: From a prospectively-built monocentric database, we identified patients aged≥18 to<60-years with strokes of undetermined etiology and complete etiological work-up, including transesophageal echocardiography. We divided patients in two groups: (i) with high-risk PFO [i.e. PFO with large interatrial shunt (>30 microbubbles) or associated with atrial septal aneurysm] and (ii) with low-risk/without PFO. We recorded the presence of arterial occlusion and large vessel occlusion (LVO) in the acute phase. RESULTS: We included 96 patients; 55 (57%) had high-risk PFO. Their median age was 48 (40-52) years, and 28 (29%) were women. The percentages of patients with arterial occlusion and with LVO were lower in the high-risk PFO group than in the low-risk/without PFO group: 11 (20%) versus 19 (46%) (P=0.008), and 5 (9%) versus 15 (37%) (P=0.002), respectively. There was no difference in the median RoPE score between groups (P=0.30). CONCLUSION: The presence of LVO could represent a "red flag" of PFO causality in stroke of undetermined etiology, and could be implemented in future PFO-related stroke classifications.

Case Report: Acute arterial occlusion of the right lower extremity due to left atrial invasion from pulmonary metastases of thyroid cancer.

Cardiac metastases of thyroid cancer are rare. The most common metastatic route is through lymphatic or hematogenous spread to the right side of the heart. Direct invasion of metastases from other adjacent organs to the left side of the heart is even rarer. In many cases, the disease progresses asymptomatically, and symptoms appear only when it is already fatal. A 68-year-old woman underwent total thyroidectomy and right-side lymph node dissection for papillary thyroid cancer and multiple lung metastases 7 years previously. The patient was referred to our hospital due to sudden pain in the right lower extremity and motor disturbance. Computed tomography revealed acute arterial occlusion of the right lower extremity due to tumor dispersal from a left atrial invasion caused by multiple pulmonary metastases of thyroid cancer, and only emergency thrombectomy was performed. Although blood flow was restored, the patient died of respiratory failure 2 months after the procedure. Radical resection is considered difficult in cases of direct invasion of metastases from other adjacent organs because multiple metastases have often already occurred. Therefore, in the terminal stage, it might be too invasive to resect a tumor only to prevent embolism recurrence. The treatment strategy should depend on the patient's prognosis and choice.