Active Vascular Lesions Research Articles

Current Perspectives in Giant Cell Arteritis: Can We Better Connect Pathogenesis and Treatment?

Giant cell arteritis (GCA) is a large-vessel vasculitis affecting elderly patients and targeting the aorta and its main branches, leading to cranial and extracranial manifestations. The mechanism behind the ischemia is a granulomatous-type inflammation with potentially critical lesions, including visual loss involving the ophthalmic artery. Despite significant progress in unraveling the pathophysiology of this disease, treatment options still rely on glucocorticoids (GCs) to overcome active vascular lesions and disease flares. However, uncertainty still revolves around the optimal dose and tapering rhythm. Few corticosteroid-sparing agents have proven useful in GCA, namely, methotrexate and tocilizumab, benefiting cumulative GC dose and relapse-free intervals. The future looks promising with regard to using other agents like abatacept and Janus-kinase inhibitors or blocking the granulocyte-macrophage colony-stimulating factor receptor.

Beyond Vessel Diameters: Non-invasive Monitoring of Flow Patterns and Immune Cell Recruitment in Murine Abdominal Aortic Disorders by Multiparametric MRI.

The pathophysiology of the initiation and progression of abdominal aortic aneurysms (AAAs) and aortic dissections (AADs) is still unclear. However, there is strong evidence that monocytes and macrophages are of crucial importance in these processes. Here, we utilized a molecular imaging approach based on background-free 19F MRI and employed perfluorocarbon nanoemulsions (PFCs) for in situ 19F labeling of monocytes/macrophages to monitor vascular inflammation and AAA/AAD formation in angiotensin II (angII)-treated apolipoproteinE-deficient (apoE−/−) mice. In parallel, we used conventional 1H MRI for the characterization of aortic flow patterns and morphology. AngII (1 μg/kg/min) was infused into apoE−/− mice via osmotic minipumps for 10 days and mice were monitored by multiparametric 1H/19F MRI. PFCs were intravenously injected directly after pump implantation followed by additional applications on day 2 and 4 to allow an efficient 19F loading of circulating monocytes. The combination of angiographic, hemodynamic, and anatomical measurements allowed an unequivocal classification of mice in groups with developing AAAs, AADs or without any obvious aortic vessel alterations despite the exposure to angII. Maximal luminal and external diameters of the aorta were enlarged in AAAs, whereas AADs showed either a slight decrease of the luminal diameter or no alteration. 1H/19F MRI after intravenous PFC application demonstrated significantly higher 19F signals in aortae of mice that developed AAAs or AADs as compared to mice in which no aortic disorders were detected. High resolution 1H/19F MRI of excised aortae revealed a patchy pattern of the 19F signals predominantly in the adventitia of the aorta. Histological analysis confirmed the presence of macrophages in this area and flow cytometry revealed higher numbers of immune cells in aortae of mice that have developed AAA/AAD. Importantly, there was a linear correlation of the 19F signal with the total number of infiltrated macrophages. In conclusion, our approach enables a precise differentiation between AAA and AAD as well as visualization and quantitative assessment of inflammatory active vascular lesions, and therefore may help to unravel the complex interplay between macrophage accumulation, vascular inflammation, and the development and progression of AAAs and AADs.

Patients with Takayasu's arteritis having persistent acute-phase response usually have an increased major vessel uptake by 18F-FDG-PET/CT

Objectives. Although not uniformly accepted, an increased uptake by 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in large vessels is accepted to be a sign of active disease in Takayasu's arteritis (TAK). We aimed to investigate the value of 18F-FDG-PET/CT for clinical assessment in a subset of TAK patients having a persistent acute-phase response (APR) without any signs or symptoms of clinical disease activity.Method. We studied 14 patients (mean age: 38.6 ± 13.9 years, Female/Male: 11/3, and disease duration: 5.7 ± 5 years). Patients were clinically inactive (according to the definition of activity by Kerr et al.), while categorized as having “persistent” disease activity by physician's global assessment due only to APR. 18F-FDG uptake was graded using a four-point scale from grade 0 (no uptake present) to grade 3 (high grade: uptake higher than that of liver). Any uptake in major vessels with a grade ≥ 2 was accepted to be “active.”Results. Mean erythrocyte sedimentation rate was 50.8 ± 13.2 mm/hour and mean C-reactive protein level was 28.5 ± 22.1 mg/L. Active vasculitic lesions were observed by 18F-FDG-PET/CT in 9 of 14 (64.3%) patients. The median number of active vascular lesions was 2 (range: 1–5). A step-up treatment change was decided in 8 patients according to 18F-FDG-PET/CT results.Conclusion. We observed increased 18F-FDG uptake in the majority of TAK patients with an increased APR, but clinically silent disease. 18F-FDG-PET/CT showed the presence and localization of active inflammation in the aorta and its branches. Although specificity for observed lesions is not clear, 18F-FDG-PET/CT imaging may influence physician's assessment of clinical activity and treatment choices in TAK.

FRI0356 Patients with takayasu’s arteritis having persistent acute phase response usually have an increased major vessel uptake by 18f-fdg-pet/ct

Background18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) is a sensitive imaging tool for large-vessel vasculitis. Although not uniformly accepted, an increased uptake by 18F-FDG PET/CT in large-vessels is accepted to be...

Multidisciplinary Approaches to Complicated Vascular Lesions of the Orbit

Hemodynamically active vascular lesions of the orbit are often clinically challenging to treat, both because of the complexity of the vascular anatomy and the delicacy of the cardinal structures that are involved and vulnerable to damage. Attempts to achieve complete embolization of such vascular lesions may result in damage to vital visual structures. Conversely, incomplete closure of the feeders or vascular shunts will usually result in recanalization and, therefore, recurrence of such lesions. Surgical excision after selective optimal embolizations may convert dynamic lesions into static ones with controlled surgical risks and could provide a solution to these problems. Cyanoacrylic polymerization was used to embolize the lesions, which were then excised with careful microsurgical and microvascular techniques. The authors present four cases of different hemodynamically active orbital vascular lesions (a post-traumatic arteriovenous fistula, a complex venous anomaly, a cavernous hemangioma of bone, and an arteriovenous malformation), which were treated successfully with the combination of presurgical embolization and surgery. The authors believe that, from their experience with these cases, a multidisciplinary approach to complicated orbital vascular lesions is ideal and practical.