COVID-19 and Peripheral Artery Thrombosis: A Mini Review

Endovascular solutions for symptomatic free-floating thrombus in thoracic aorta in rheumatoid arthritis patients: Two clinical cases

OBJECTIVES

We present two clinical cases of association between symptomatic free-floating thrombus (FFT) in thoracic aorta and rheumatoid arthritis (RA).

METHODS

In the first patient, we observed a recent onset of peripheral and visceral signs of embolization: after a first treatment with anticoagulation, our Aortic team scheduled the coverage of FFT (sited in zone 1 of the aortic arch) with an anatomical debranching of anonymous trunk and left carotid artery, a left carotid-subclavian bypass, and a TEVAR of the aortic arch with proximal landing in zone 0 of the arch. The second case was characterized by chest pain, left upper limb ischemia, and CTA evidence of an FFT in zone 3 of the aortic arch; we planned a chimney-TEVAR on the left subclavian artery and descending thoracic aorta (with proximal landing in zone 2 of the aortic arch) to exclude the FFT.

RESULTS

No complications resulted and no new embolic episodes were registered.

CONCLUSIONS

Evaluating the aorta is warranted in all patients with peripheral emboli of uncertain pathogenesis. In our opinion, the endovascular treatment of a symptomatic FFT could represent an effective and safe solution in a patient fit for endovascular surgery, but larger studies are required to define a personalized treatment strategy.

An early warning indicator of mortality risk in patients with COVID-19: the neutrophil extracellular traps/neutrophilic segmented granulocyte ratio

Background

Neutrophil extracellular traps (NETs) play a key role in thrombus formation in patients with coronavirus disease 2019 (COVID-19). However, the existing detection and observation methods for NETs are limited in their ability to provide quantitative, convenient, and accurate descriptions of in situ NETs. Therefore, establishing a quantitative description of the relationship between NETs and thrombosis remains a challenge.

Objective

We employed morphological observations of blood cells and statistical analyses to investigate the correlation between the NETs/neutrophilic segmented granulocyte ratio and mortality risk in patients with COVID-19.

Methods

Peripheral blood samples were collected from 117 hospitalized patients with COVID-19 between November 2022 and February 2023, and various blood cell parameters were measured. Two types of smudge cells were observed in the blood and counted: lymphatic and neutral smudge cells. Statistical data analysis was used to establish COVID-19 mortality risk assessment indicators.

Results

Morphological observations of neutrophilic smudge cells revealed swelling, eruption, and NETs formation in the neutrophil nuclei. Subsequently, the NETs/neutrophilic segmented granulocyte ratio (NNSR) was calculated. A high concentration of NETs poses a fatal risk for thrombus formation in patients. Statistical analysis indicated that a high NNSR was more suitable for evaluating the risk of death in patients with COVID-19 compared to elevated fibrinogen (FIB) and D-dimer (DD) levels.

Conclusion

Observing blood cell morphology is an effective method for the detection of NETs, NNSR are important markers for revealing the mortality risk of patients with COVID-19.

Acute limb ischemia caused by floating thrombus in the aorta: a case report and literature review

This report presents a patient with rheumatoid arthritis and COVID-19 infection one month earlier who experienced embolic episodes resulting in acute lower-limb ischemia from an unusual source. The blood flow was successfully restored by femoropopliteal thromboembolectomy. In determining the source of the embolism, the patient underwent electrocardiogram, transthoracic echocardiogram, and aortic CTA. The latter revealed a large, pedunculated, and mobile thrombus arising from the aortic arch and the descending thoracic aorta. Considering the patient's general health condition, we performed anticoagulation of the floating thrombus in the aortic lumen. The mechanism of aortic floating thrombosis exhibits considerable complexity. There are no standardized treatment protocols or clinical guidelines, and its treatment mainly includes open surgery, aortic endoluminal stent -graft insertion and pharmacological anticoagulation. Treatment strategy should be based on the cause of the disease and the patient's physical condition.

Aortic dissection and Covid-19; a comprehensive systematic review

Coronavirus disease 19 (Covid-19) has been declared as a pandemic disease since March 2020; causing wide array of signs and symptoms, many of which result in increased mortality rates worldwide. Although it was initially known as an acute respiratory disease, Covid-19 is accompanied with several extrapulmonary manifestations, of which the cardiovascular ones are of major importance. Among other cardiovascular complications of Covid-19, aortic dissection has been a significant yet underrated problem. The pathophysiology of aortic dissection consists of various inflammatory pathways, that could be influenced by Covid-19 infection. We herein have reviewed articles inclusive of aortic dissection concurrent with Covid-19 infection in a systematic manner, along with the probable similarities in pathophysiology of aortic dissection with Covid-19 infection.

Renal artery thrombosis as a long-term complication of COVID-19

Coronavirus disease 2019 (COVID-19) has been extensively associated with microvascular and macrovascular thrombosis. Several reports have demonstrated a link between COVID-19 and pulmonary embolism, deep vein thrombosis, myocardial infarction, stroke, and aortic thrombosis. Renal artery thrombosis is of special interest because of its life-threatening consequences, such as acute kidney injury and renal infarction. We present a case of left renal artery thrombosis as a long-term complication of COVID-19. Moreover, we demonstrate the effectiveness of interventional radiology to regain vascularization of the affected kidney.

Neurological complications associated with Covid-19; molecular mechanisms and therapeutic approaches

With the progression of investigations on the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), neurological complications have emerged as a critical aspect of the ongoing coronavirus disease 2019 (Covid‐19) pandemic. Besides the well‐known respiratory symptoms, many neurological manifestations such as anosmia/ageusia, headaches, dizziness, seizures, and strokes have been documented in hospitalised patients. The neurotropism background of coronaviruses has led to speculation that the neurological complications are caused by the direct invasion of SARS‐CoV‐2 into the nervous system. This invasion is proposed to occur through the infection of peripheral nerves or via systemic blood circulation, termed neuronal and haematogenous routes of invasion, respectively. On the other hand, aberrant immune responses and respiratory insufficiency associated with Covid‐19 are suggested to affect the nervous system indirectly. Deleterious roles of cytokine storm and hypoxic conditions in blood‐brain barrier disruption, coagulation abnormalities, and autoimmune neuropathies are well investigated in coronavirus infections, as well as Covid‐19. Here, we review the latest discoveries focussing on possible molecular mechanisms of direct and indirect impacts of SARS‐CoV‐2 on the nervous system and try to elucidate the link between some potential therapeutic strategies and the molecular pathways.