Moyamoya Vasculopathy and Moyamoya-Related Systemic Vasculopathy: A Review With Histopathological and Genetic Viewpoints.

Systemic vasculopathy has occasionally been reported in cases of moyamoya disease (MMD). Since the pathological relationship between moyamoya vasculopathy (MMV) and moyamoya-related systemic vasculopathy (MMRSV) remains unclear, it was examined herein by a review of histopathologic studies in consideration of clinicopathological and genetic viewpoints. Although luminal stenosis was a common finding in MMV and MMRSV, histopathologic findings of vascular remodeling markedly differed. MMV showed intimal hyperplasia, marked medial atrophy, and redundant tortuosity of the internal elastic lamina, with outer diameter narrowing called negative remodeling. MMRSV showed hyperplasia, mainly in the intima and sometimes in the media, with disrupted stratification of the internal elastic lamina. Systemic vasculopathy has also been observed in patients with non-MMD carrying the RNF213 (ring finger protein 213) mutation, leading to the concept of RNF213 vasculopathy. RNF213 vasculopathy in patients with non-MMD was histopathologically similar to MMRSV. Cases of MMRSV have sometimes been diagnosed with fibromuscular dysplasia. Fibromuscular dysplasia is similar to MMD not only in the histopathologic findings of MMRSV but also from clinicopathological and genetic viewpoints. The significant histopathologic difference between MMV and MMRSV may be attributed to a difference in the original vascular wall structure and its resistance to pathological stress between the intracranial and systemic arteries. To understand the pathogeneses of MMD and MMRSV, a broader perspective that includes RNF213 vasculopathy and fibromuscular dysplasia as well as an examination of the 2- or multiple-hit theory consisting of genetic factors, vascular structural conditions, and vascular environmental factors, such as blood immune cells and hemodynamics, are needed.

Fibromuscular dysplasia of subclavian artery: A case report and mini-review.

A case of a 40-year-old male patient with a right subclavian artery aneurysm of fibromuscular dysplasia origin is reported. The patient presented with thoracic outlet-like symptoms and underwent aneurysm resection. Microscopic examination revealed intimal and medial fibroplasia. Additional cases of fibromuscular dysplasia at this rare location are reviewed, indicating a male and right-sided predominance. The most frequent clinicopathological manifestation was an aneurysm, with the histopathological pattern characterized by medial fibroplasia. Treatment modalities included the use of either graft prosthesis or end-to-end anastomosis.

Fibromuscular dysplasia of the coronary arteries: An unusual case of sudden death and review of the literature.

Fibromuscular dysplasia of the coronary is an uncommon coronary defect with a range of pathological alterations and unpredictable clinical description that can cause sudden death. We present an autopsy case of sudden cardiac death due to a rupture of a coronary artery aneurysm in a 59-year-old woman. Postmortem autopsy revealed two huge saccular aneurysms located at the right coronary artery, one of which was ruptured leading to a fatal hemopericardium. Histopathological examination revealed coronary artery fibromuscular dysplasia with fibromyxoid dissociation of the media causing saccular aneurysms. The involvement of coronary arteries in fibromuscular dysplasia with aneurysmal features has been rarely reported in the literature and is most likely an underdiagnosed finding. Due to the little number of published studies, the etiology is not fully understood and data on pathogenesis, risk factors, manifestation, disease course, and mortality are still unclear, which is a gap that needs to be filled in order to avoid under-diagnosis of the disease. Our case report aimed to discuss the mechanisms of sudden death attributed to coronary fibromuscular dysplasia.

Lesions of the Cardiac Conduction System and Sudden Death.

ABSTRACT: When a young previously healthy person dies suddenly, occasionally, the scene is noncontributory and the autopsy and drug screen are negative. In such cases, additional studies, including genetic assessment and cardiac conduction system examination, should be performed. We performed a literature search and reviewed our own material to identify possible or definite conduction system anomalies that may cause death. We identified intrinsic conduction system disease including cystic tumor of the atrioventricular node, atrioventricular node (cystic tumor of the AV node), and fibromuscular dysplasia of the atrioventricular node artery to be likely causes of death. Extrinsic causes, in which a generalized disease affects the conduction system, include tumors, autoimmune disease, infiltrative disorders, and others, are a second category of diseases that can affect the conduction system and cause atrioventricular block and sudden death.

Is carotid web an arterial wall dysplasia? A histological series.

INTRODUCTION: Described for 60 years under various names, the carotid web is a suspected cause of cryptogenic stroke, especially in young patients. The web creates an intraluminal protrusion that may contribute to turbulent flow and thrombus embolization into cerebral arteries. Although the carotid web has frequently been related to arterial fibrodysplasia, its natural history and pathological description remain unclear. PATIENTS: Among all consecutive patients admitted to the stroke unit of Sainte-Anne Hospital and referred to the vascular surgery department from January 2015 to December 2022, we retrospectively identified 9 patients with a carotid web. The surgical specimens of the 9 patients were submitted to systematic pathological analysis. RESULTS: The patients with a histologically confirmed carotid web were young (median age was 42 years), prominently women (7/9), and presenting with low cardiovascular risk. Eight patients had a stroke proven by a magnetic resonance imaging, and 1 had transient monocular amaurosis. The typical pathological lesion supporting the imaging pattern of the carotid web was a focal eccentric intimal hyperplasia forming a protruding lesion characterized by a population of vascular smooth muscle cells intermingled in an abundant, most often loose extracellular matrix. Pathologically proven thrombus was observed in 4 cases. Importantly atherosclerosis was absent. CONCLUSION: Histological features in our 9 cases strengthen carotid web characterization as a homogeneous pattern of localized intimal hyperplasia. It is a unique entity consistent with intimal fibroplasia, distinct from medial fibromuscular dysplasia and early atherosclerosis.

[Arterial fibromuscular dysplasia as a factor in sudden cardiac death in young adults]. / Fibromuskulyarnaya displaziya arterii ­ odin iz faktorov vnezapnoi serdechnoi smerti lits molodogo vozrasta.

The objective of the study is to consider the problem of diagnostics of a rare vasculopathy, fibromuscular dysplasia of coronary arteries, by the case study of a 19-year-old serviceman, an athlete with sudden death occurred during slight physical exertion. After repeated histological examination as part of the forensic medical examination, the diagnosis was made: «multifocal fibromuscular dysplasia of the coronary arteries and ascending aortic arch, complicated by acute left ventricular failure.¼ This disease often manifests with the acute coronary syndrome in people of young age. Therefore, special attention was given to the macroscopic and histological features of fibromuscular dysplasia of arteries.

Coronary fibromuscular dysplasia with three-vessel involvement: a rare cause of ischaemic dilated cardiomyopathy in a very young male.

Coronary artery disease of non-atherosclerotic aetiology, while rare in incidence, can have a wide aetiology, such as fibromuscular dysplasia, which is a non-inflammatory arteriopathy of numerous histopathological types of fibromuscular tissue accumulation. This brief report describes the case of a 22-year-old male with a recently developed dilated cardiomyopathy and a history of aborted cardiac arrest at the age of 14 years. Coronary angiogram revealed severe three vessels disease, while optical coherence tomography established fibromuscular dysplasia as aetiology. Balloon and stent angioplasty was performed guided by fractional flow reserve with acceptable angiographic result.

Endovascular interventions in main renal artery pathologies: an overview and update.

Renal arteries are involved in a wide spectrum of pathologies including atherosclerosis, fibromuscular dysplasia, Takayasu arteritis, aneurysms, and aortic type B dissections extending into main renal arteries. They manifest as renovascular hypertension, renal ischemia, and cardiovascular dysfunction. The location of the renal arteries in relation to the abdominal aortic aneurysm is a critical determinant of interventional options and long-term prognosis. This article provides a comprehensive review of the role of interventional radiologists in transcatheter interventions in various pathologies involving the main renal arteries with analysis of epidemiology, pathophysiology, newer interventional techniques, and management options.

Increased Collagen Turnover Is a Feature of Fibromuscular Dysplasia and Associated With Hypertrophic Radial Remodeling: A Pilot, Urine Proteomic Study.

Fibromuscular dysplasia (FMD), a nonatherosclerotic, noninflammatory disease of medium-sized arteries, is an underdiagnosed disease. We investigated the urinary proteome and developed a classifier for discrimination of FMD from healthy controls and other diseases. We further hypothesized that urinary proteomics biomarkers may be associated with alterations in medium-sized, but not large artery geometry and mechanics. The study included 33 patients with mostly multifocal, renal FMD who underwent in depth arterial exploration using ultra-high frequency ultrasound. The cohort was separated in a training set of 23 patients with FMD from Belgium and an independent test set of 10 patients with FMD from Italy. For each set, controls matched 2:1 were selected from the Human Urinary Proteome Database. The specificity of the classifier was tested in 700 additional controls from general population studies, patients with chronic kidney disease (n=66) and coronary artery disease (n=31). Three hundred thirty-five urinary peptides, mostly related to collagen turnover, were identified in the training cohort and combined into a classifier. When applying in the test cohort, the area under the receiver operating characteristic curve was 1.00, 100% specificity at 100% sensitivity. The classifier maintained a high specificity in additional controls (98.3%), patients with chronic kidney (90.9%) and coronary artery (96.8%) diseases. Furthermore, in patients with FMD, the proteomic score was positively associated with radial wall thickness and wall cross-sectional area. In conclusion, a proteomic score has the potential to discriminate between patients with FMD and controls. If confirmed in a wider and more diverse cohort, these findings may pave the way for a noninvasive diagnostic test of FMD.

FMD and SCAD: Sex-Biased Arterial Diseases With Clinical and Genetic Pleiotropy.

Multifocal fibromuscular dysplasia (FMD) and spontaneous coronary artery dissection are both sex-biased diseases disproportionately affecting women over men in a 9:1 ratio. Traditionally known in the context of renovascular hypertension, recent advances in knowledge about FMD have demonstrated that FMD is a systemic arteriopathy presenting as arterial stenosis, aneurysm, and dissection in virtually any arterial bed. FMD is also characterized by major cardiovascular presentations including hypertension, stroke, and myocardial infarction. Similar to FMD, spontaneous coronary artery dissection is associated with a high prevalence of extracoronary vascular abnormalities, including FMD, aneurysm, and extracoronary dissection, and recent studies have also found genetic associations between the two diseases. This review will summarize the relationship between FMD and spontaneous coronary artery dissection with a focus on common clinical associations, histopathologic mechanisms, genetic susceptibilities, and the biology of these diseases. The current status of disease models and critical future research directions will also be addressed.

Standing Waves on Computed Tomography Angiography in Multiple Vessels in a Young Trauma Patient.

ABSTRACT: Standing waves are a phenomenon of uncertain etiology seen on imaging. We present the first case demonstrating standing waves on computed tomography angiography in multiple vessels in a single patient with imaging evidence of resolution in some of the vessels. Our case further supports the literature that standing waves are a physiologic phenomenon, likely because of flow mechanics, rather than modality.

Detection of Carotid Webs by CT Angiography, High-Resolution MRI, and Ultrasound.

BACKGROUND AND PURPOSE: We sought to examine carotid webs (intimal variant fibromuscular dysplasia) by studying their clinical features and imaging profiles. METHODS: All patients (n = 893) of the Department of Neurology at Beijing Tiantan Hospital between January and December 2019 were retrospectively reviewed for computed tomography angiography (CTA), high-resolution magnetic resonance imaging (HRMRI), and Doppler ultrasound data. Carotid webs were identified by two experienced neuroimaging experts according to the characteristics of a thin intraluminal filling defect along the posterior wall of the carotid bulb on sagittal CTA and a septum structure in arteries on axial CTA. RESULTS: We found eight carotid web patients by CTA and Doppler ultrasound. Four of eight (50%) carotid webs were observed in the bilateral carotid arteries and other four of eight (50%) were ipsilateral. The mean age of the 8 patients was 50.75 (range 38-65) years; two were in women. Six of 8 patients (75%) with carotid webs had acute ischemic stroke. Two-thirds of patients with ischemic stroke were treated with carotid revascularization. Doppler ultrasound indicated that the septum projected into the carotid arteries in all patients. Half of the carotid web patients underwent HRMRI, showing features consistent with CTA findings. The Cohen's kappa coefficient for interobserver agreement in diagnosing carotid webs was .76. CONCLUSIONS: Doppler ultrasound combined with CTA and HRMRI is effective and reliable method to identifying carotid webs, which may be associated with stroke.

Carotid web: an occult mechanism of embolic stroke.

The carotid web is a proposed stroke mechanism that may underlie cryptogenic stroke, particularly in younger patients without vascular risk factors. The web appears as a shelf-like projection into the lumen of the proximal cervical internal carotid artery without evidence of calcification. It is pathologically defined as intimal fibromuscular dysplasia. Altered haemodynamics distal to the web cause flow stagnation and remote embolisation of fibrin-based clots. It is best demonstrated and diagnosed on CT angiography (CTA) of the neck because of its ability to resolve calcium and create multiplanar reconstructions. Although they can be readily visualised on CTA, carotid webs may be missed or misinterpreted because they do not typically cause haemodynamically significant stenosis and can mimic arterial dissection, non-calcified atherosclerotic plaque and intraluminal thrombus. Options for management include antiplatelet therapy, carotid endarterectomy and carotid artery stenting. Modern management strategies for cryptogenic stroke include long-term cardiac monitoring, further investigation for structural cardiac disease and a diagnostic workup for arterial hypercoagulability, however, these strategies are not likely to capture the possibility of a carotid web. Carotid webs should be suspected in a young patient presenting with recurrent unihemispheric strokes particularly when conventional vascular risk factors are not present.

A Novel Recurrent COL5A1 Genetic Variant Is Associated With a Dysplasia-Associated Arterial Disease Exhibiting Dissections and Fibromuscular Dysplasia.

OBJECTIVE: While rare variants in the COL5A1 gene have been associated with classical Ehlers-Danlos syndrome and rarely with arterial dissections, recurrent variants in COL5A1 underlying a systemic arteriopathy have not been described. Monogenic forms of multifocal fibromuscular dysplasia (mFMD) have not been previously defined. Approach and Results: We studied 4 independent probands with the COL5A1 pathogenic variant c.1540G>A, p.(Gly514Ser) who presented with arterial aneurysms, dissections, tortuosity, and mFMD affecting multiple arteries. Arterial medial fibroplasia and smooth muscle cell disorganization were confirmed histologically. The COL5A1 c.1540G>A variant is predicted to be pathogenic in silico and absent in gnomAD. The c.1540G>A variant is on a shared 160.1 kb haplotype with 0.4% frequency in Europeans. Furthermore, exome sequencing data from a cohort of 264 individuals with mFMD were examined for COL5A1 variants. In this mFMD cohort, COL5A1 c.1540G>A and 6 additional relatively rare COL5A1 variants predicted to be deleterious in silico were identified and were associated with arterial dissections (P=0.005). CONCLUSIONS: COL5A1 c.1540G>A is the first recurring variant recognized to be associated with arterial dissections and mFMD. This variant presents with a phenotype reminiscent of vascular Ehlers-Danlos syndrome. A shared haplotype among probands supports the existence of a common founder. Relatively rare COL5A1 genetic variants predicted to be deleterious by in silico analysis were identified in ≈2.7% of mFMD cases, and as they were enriched in patients with arterial dissections, may act as disease modifiers. Molecular testing for COL5A1 should be considered in patients with a phenotype overlapping with vascular Ehlers-Danlos syndrome and mFMD.

Post-traumatic aneurysmal rupture involving the circle of Willis affected by fibromuscular dysplasia. A case report and systematic review.

The fatal rupture of a saccular aneurysm at the junction between the left anterior cerebral artery and anterior communicating artery affected by fibromuscular dysplasia (FMD) is a rare condition. Here is reported the case of a subject involved in a road traffic accident a few minutes before the death, which opened the debate on the real cause of death in a forensic setting. By autopsy, the examination of the brain revealed subarachnoid haemorrhage with flooding of the ventricles due to the breached saccular aneurysm of the junction between the left anterior cerebral artery and anterior communicating artery, in FMD mainly affecting the circle of Willis arteries. A spontaneous aneurysmal rupture was excluded on the basis of probabilistic analysis, in the presence of alternative hypotheses that could explain the facts. The passenger's delayed loss of consciousness may be explained as much by a hypertension-linked rupture of the aneurysm triggered by the emotional stress experienced, as by the traumatic shaking/impact of the aneurysm against the bony skull structures, in a subject predisposed to aneurysm frailty due to FMD. Overall, the concausal role of both the road traffic accident, typified by high kinetic energy, and the presence of a pre-existing aneurysmatic weakness due to FMD is fully recognized. The identification of anatomical variants, jointly with uncommon diseases at the examination of the brain base arteries in any case of isolated basal subarachnoid haemorrhage, may avoid wrong legal consequences even when the cause of death seems to be obviously of simple traumatic origin.

Moyamoya disease associated with fibromuscular dysplasia of intrapulmonary bronchial arteries-a case report.

A case is reported of a 40-year-old woman clinically diagnosed as moyamoya disease with associated fibromuscular dysplasia of intrapulmonary bronchial arteries incidentally revealed during autoptic examination. Moyamoya disease represents an idiopathic noninflammatory and nonatherosclerotic arterio-occlusive process of intracranial arteries. Prolonged brain ischemia leads to formation of tiny and fragile collaterals. Clinically, patients with moyamoya angiopathy commonly present with severe neurological symptoms caused by brain infarction or hemorrhage. Histologically, the steno-occlusive process is based on fibrocellular thickening of intima and intimal smooth muscle cell proliferation. In the literature, extracranial arterial involvement, i.e. fibromuscular dysplasia of renal or pulmonary arteries, has been described in several cases of moyamoya disease. Our aim is to show a unique case of moyamoya disease associated with fibromuscular dysplasia affecting an uncommon site.