Fibromuscular dysplasia of the renal arteries: what do we know in 2024? / Dysplasie fibromusculaire des artères rénales : que savons-nous en 2024 ?

Fibromuscular dysplasia (FMD) is a rare nonatherosclerotic, noninflammatory vascular disease affecting mostly renal and carotid arteries and is the second most frequent cause of renal artery stenosis. The symptomatology is dominated by arterial hypertension due to the frequent involvement of the renal arteries and depends on the location of the lesions. Most of the cases are middle-aged women of Caucasian origin. There are two subtypes based on angiographic aspect: multifocal FMD (80% of the cases) and focal FMD (rarer with a more balanced sex ratio). Angioplasty of the renal arteries is generally disappointing with less than 50% cure of hypertension. It appears necessary to improve our knowledge of the FMD and to optimize the selection of eligible patients for revascularization with transdisciplinary collegial therapeutic decision.

La dysplasie fibromusculaire (DFM) est une maladie rare caractérisée par des sténoses segmentaires non artérioscléreuses, non inflammatoires, des artères de moyens calibres, touchant surtout les artères rénales et les carotides. Elle constitue la seconde cause de sténoses des artères rénales. La symptomatologie dépend de la localisation des lésions et est dominée par l'hypertension artérielle (HTA) en raison de l'atteinte fréquente des artères rénales. Cette pathologie touche majoritairement les femmes caucasiennes d'âge moyen. Il en existe deux sous-types, basés sur l'aspect angiographique : la DFM multifocale (80 % des cas) et la DFM focale (plus rare, sex ratio plus équilibré). Les résultats des prises en charge interventionnelle s'avèrent globalement décevants avec moins de 50 % de guérison de l'HTA. Il est nécessaire d'améliorer nos connaissances sur la physiopathologie de la DFM et d'optimiser la sélection des patients éligibles à une revascularisation par une prise de décision thérapeutique collégiale, en réunion de concertation pluridisciplinaire.

Renal Autotransplantation for Uncontrolled Hypertension in Nonatherosclerotic Renal Artery Stenosis-2 Case Reports and a Brief Review of the Literature.

Fibromuscular dysplasia is the most common cause of renovascular hypertension in young adults under 40 years old. It is potentially amenable to renal artery angioplasty, which frequently normalizes blood pressure. However, limited options exist if angioplasty is not technically possible, or restenosis occurs. Here, we describe 2 patients who presented with hypertension secondary to renal artery stenosis. In the first case, a young adult with hypertension secondary to renal artery stenosis (fibromuscular dysplasia), developed restenosis 11 weeks after an initially successful renal artery angioplasty. In the second case, a patient with neurofibromatosis type 1 was diagnosed with hypertension secondary to renal artery stenosis. Angioplasty was not possible due to multiple branch occlusions. Both individuals went on to have successful renal autotransplantations, which ultimately cured their hypertension. In this article, we review the background, indications, and blood pressure outcomes in relation to renal autotransplantation in nonatherosclerotic renal artery stenosis.

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.

A Rare Case of Focal Renal Fibromuscular Dysplasia Treated With Angioplasty: A Case Report.

BACKGROUND: Fibromuscular dysplasia is an idiopathic, segmental, nonatherosclerotic, noninflammatory vascular disease that can lead to arterial stenosis, tortuosity, occlusion, aneurysms, and dissection. Fibromuscular dysplasia is a rare cause of hypertension that can easily be missed. To date, there has been no definitive treatment for fibromuscular dysplasia. CASE REPORT: In this report, we present an uncommon case of renovascular hypertension in a 21-year-old non-white female with a 3-year history of hypertension secondary to fibromuscular dysplasia involving bilateral renal arteries. Computed tomography angiography during the arterial phase revealed distal focal narrowing of the right main renal artery, distal focal narrowing of the left main renal artery, and proximal focal narrowing of the left accessory lower renal artery. Percutaneous balloon dilatation of the stenotic lesion was performed successfully up to 1 year After the procedure, the arterial blood pressure was within the normal range (110/70 to 125/75 mmHg) without medication. After 1 year of follow-up, CTA revealed re-stenosis in left main renal artery without clinical symptoms and normal blood pressure. Repeated procedure was done successfully. CONCLUSIONS: This case report highlights the difficulty in the diagnosis and treatment of focal fibromuscular dysplasia in young non-white female patients. Computerized tomographic angiography is a useful tool for identifying the cause and showing the benefit of percutaneous transluminal renal angioplasty treatment for this rare entity, as an early percutaneous angioplasty intervention may have a clinical cure for hypertension.

Risks and benefits of renal artery stenting in fibromuscular dysplasia: Lessons from the ARCADIA-POL study.

INTRODUCTION: Although renal stenting is the standard revascularization method for atherosclerotic renal artery stenosis (RAS) (FMD-RAS), stenting in fibromuscular dysplasia (FMD) RAS is usually limited to periprocedural complications of angioplasty and primary arterial dissection. The main aim of the study was to retrospectively analyze the immediate and long-term results of renal stenting versus angioplasty in patients with FMD. METHODS: Of 343 patients in the ARCADIA-POL registry, 58 patients underwent percutaneous treatment due to FMD-RAS (in 70 arteries). Percutaneous transluminal renal angioplasty (PTRA) was performed as an initial treatment in 61 arteries (PTRA-group), whereas primary stenting was undertaken in nine arteries (stent-group). Stent-related complications were defined as: in-stent restenosis > 50% (ISR); stent fracture; under-expansion; or migration. RESULTS: In the PTRA-group, the initial restenosis rate was 50.8%. A second procedure was then performed in 22 arteries: re-PTRA (12 arteries) or stenting (10 arteries). The incidence of recurrent restenosis after re-PTRA was 41.7%. Complications occurred in seven of 10 (70%) arteries secondarily treated by stenting: two with under-expansion and five with ISR. In the stent-group, stent under-expansion occurred in one case (11.1%) and ISR in three of nine stents (33.3%). In combined analysis of stented arteries, either primarily or secondarily, stent-related complications occurred in 11/19 stenting procedures (57.9%): three due to under-expansion and eight due to ISRs. Finally, despite several revascularization attempts, four of 19 (21%) stented arteries were totally occluded and one was significantly stenosed at follow-up imaging. CONCLUSION: Our study indicates that renal stenting in FMD-RAS may carry a high risk of late complications, including stent occlusion. Further observational data from large-scale registries are required.

Reversible Cerebral Vasoconstriction Syndrome And Fibromuscular Dysplasia: An Epiphenomenon Or A Causal Relationship?

Fibromuscular dysplasia (FMD) is a rare non-atherosclerotic arterial disease that primarily affects middle-aged Caucasian women. Carotid web (CW) is a variant of FMD characterized by a nonatheromatous, membrane-like tissue protrusion into the carotid bulb. Reversible cerebral vasoconstriction syndrome (RCVS) is defined by severe headaches and reversible narrowing of cerebral arteries, which typically resolves within three months. While most RCVS cases have identifiable triggers, a significant portion occurs without known causes. Recent studies have reported a high prevalence of neurovascular abnormalities in RCVS patients. We present a case of a thirty-year-old woman with a sudden-onset severe headache, diagnosed with RCVS associated with carotid web. The patient had no ischemic involvement and responded well to flunarizine treatment. Follow-up imaging showed no stenosis. This case highlights a potential association between carotid web and RCVS, suggesting that FMD may contribute to vascular hyperreactivity and presents as a risk factor for RCVS. Further investigations are needed to understand the underlying mechanisms connecting these two vascular disorders. Keywords: reversible vasoconstriction syndrome; fibromuscular dysplasia; carotid web; structural abnormalities; vascular hyperreactivity.

Not So Benign Chest Pain in the Young: A Story of Spontaneous Coronary Artery Dissection and Fibromuscular Dysplasia.

Spontaneous coronary artery dissection (SCAD) is a rare clinical entity, often presenting similar to atherosclerotic acute coronary syndrome (ACS), although it is a non-atherosclerotic, non-traumatic, and non-iatrogenic coronary artery pathology. We report the case of a 36-year-old woman who presented with substernal, pressure-like chest pain without aggravating, alleviating, or associated symptoms. Initial evaluation revealed elevated troponin levels which peaked at 8.71 ng/mL. Electrocardiogram showed borderline J point elevation in the lateral leads. A transthoracic echocardiography revealed mild left ventricular dysfunction with an estimated ejection fraction of 45% to 50%, an akinetic apex with hyperdynamic basal segments, suggestive of stress cardiomyopathy. However, a left anterior descending artery (LAD) infarction could not be excluded. Emergent coronary angiography revealed SCAD of the LAD. No coronary interventions were performed. The patient was managed medically with dual antiplatelet therapy and beta-blockers. Given the high suspicion for fibromuscular dysplasia (FMD), computed tomographic angiography (CTA) of the head to pelvis was performed. The CTA neck showed bilateral focal areas of mild stenosis and dilation of the distal cervical internal carotid artery, and CTA abdomen revealed multiple splenic artery aneurysms, diagnostic of FMD. Unlike atherosclerotic ACS, our patient was managed medically without percutaneous intervention. This case illustrates the rare occurrence of myocardial injury due to SCAD which results in spontaneous intramural hematoma formation rather than atherosclerotic plaque rupture typically seen in ACS. FMD remains the most commonly associated condition with SCAD.

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.

The Effect of Endovascular Treatment of Renal Artery Stenoses on Coexistent Aneurysms Associated with Fibromuscular Dysplasia.

PURPOSE: Endovascular data on patients with coexistent renal artery stenosis (RAS) and renal artery aneurysm (RAA) caused by fibromuscular dysplasia (FMD) are scarce, and the outcomes from RAS-specific treatment on RAA remain unclear. This study aimed to evaluate the safety and effectiveness of RAS-specific endovascular management in patients with coexisting RAA caused by FMD. MATERIALS AND METHODS: Clinical and endovascular data on 19 patients with coexistent RAS and RAA caused by FMD who underwent RAS-specific endovascular therapy were analyzed prospectively. An RAA located within 10 mm of the RAS was defined as a stenosis-related RAA (SRAA), and long-term outcomes were evaluated. RESULTS: Nineteen patients (24 RASs and 30 RAAs) underwent endovascular therapy. Twenty-one RASs were treated with balloon angioplasty alone, whereas 3 RASs were treated with stent implantation. None of the RAAs were treated directly. During an average of 4.2 years ± 3.2 of follow-up, systolic and diastolic blood pressures decreased from 183.0 mm Hg ± 19.5 and 120.2 mm Hg ± 19.0 to 127.9 mm Hg ± 10.3 and 80.9 mm Hg ± 6.9, respectively; the number of antihypertensive medications reduced from 1.7 ± 1.0 to 0.8 ± 0.3 (for all, P < .001). The serum creatinine level remained stable. The maximum diameter of all RAAs decreased from 14.6 mm ± 9.7 to 11.3 mm ± 8.4 (P < .001). There was a significant difference in the improvement rate of the maximum diameter between SRAAs (65.0%, 13 of 20) and non-SRAAs (20.0%, 2 of 10) (P = .019). CONCLUSIONS: RAS-specific endovascular therapy is safe and effective and possibly aids in preventing RAA progression in patients with FMD with coexistent RAS and RAA.

Renovascular Hypertension with Progressive Atherosclerotic Renal Artery Stenosis in an Elderly Patient with Known Fibromuscular Dysplasia: A Case Report.

BACKGROUND Atherosclerotic renal artery stenosis (ARAS) and renovascular fibromuscular dysplasia (FMD) are 2 of the most common etiologies of renovascular hypertension. They have different pathophysiologies, risk factors, presentations, and treatment options. However, as our population ages, it can become increasingly common to see patients who previously had FMD who develop ARAS at an advanced age, indicated by recurrent renovascular hypertension. CASE REPORT We present a case of a 66-year-old female patient who, in 2007, had presented with uncontrolled hypertension. She underwent magnetic resonance angiography and was found to have bilateral FMD, for which she received balloon angioplasty to a severe lesion on the mid-right renal artery and subsequently had normalization of blood pressures and resolution of symptoms. In 2021 she returned with uncontrolled hypertension while being treated with 3 antihypertensives. Bilateral renal arteriography revealed new severe ostial stenosis of the left renal artery and a patent right renal artery in which balloon angioplasty was performed 14 years ago. Based on the angiographic pattern of this new left RAS, we concluded this lesion was caused by atherosclerosis. The left ostial lesion was treated with a bare-metal stent and the patient was continued on antihypertensive medication and statin; at follow-up 4 months later, her blood pressures had normalized. CONCLUSIONS This case features a patient who developed severe ARAS with underlying history of bilateral renal artery FMD. Clinicians need to be aware that in patients with FMD, worsening renovascular hypertension at an advanced age could indicate the development of new hemodynamically significant ARAS. These patients need repeat diagnostic testing and treatment with medial optimization with or without endovascular revascularization in the appropriate clinical setting.

Transient ischemic attack due to dynamic evolution of carotid artery web.

Carotid artery web (CaW) is a rare focal fibromuscular dysplasia, which is an underappreciated risk factor for transient ischemic attack. This case illustrates the dynamic evolution of secondary thrombus and plaque in CaW, and the importance of carotid doppler ultrasound in early detection and follow-up.

Prevalence and clinical characteristics of renovascular hypertension associated with fibromuscular dysplasia in China.

OBJECTIVES: The aim of this study was to investigate the clinical characteristics of renal artery fibromuscular dysplasia (FMD) in patients in China and identify the cure rate of hypertension after angioplasty. METHODS: Consecutive hypertensive patients with renal artery stenosis caused by FMD who underwent catheter-based angiography, and were followed at two Chinese referral centres, were retrospectively analysed. All patients underwent a detailed investigation, including demographic characteristics, clinical characteristics, biochemical sampling, Doppler ultrasonography of carotid arteries, magnetic resonance angiography (MRA) of the intracranial artery, and CTA or MRA of the abdominal artery and catheter-based renal angiography. Patients were routinely followed up at 1 month, 6 months and every year after the procedure. RESULTS: Among 245 study participants, with a mean diagnosed age of 26.9 ±â€Š9.9 years, 137 (55.9%) were women, and 38 (15.5%) were children. All patients were diagnosed with hypertension at a mean age of 23.4 ±â€Š8.4 years. There were 73.5% focal and 15.2% multivessel cases. Aneurysms, arterial dissections and total occlusions were found in 21.6, 4.1 and 12.2% of patients, respectively. Patients with multifocal FMD were older (26.0 vs. 23.7 years, P  = 0.021) and more often female (70.8 vs. 50.6%, P  = 0.004). Among children with renal FMD, 55.2% were men, and 86.8% were focal. After a median follow-up of 7.0 years, multifocal FMD had a higher cure rate of hypertension than focal FMD after revascularization (71.7 vs. 55.8%, P  = 0.032). CONCLUSION: In a cohort of mostly young Chinese patients, the prevalence of hypertension associated with renal FMD is similar in both sexes. Focal FMDs were more frequent than the multifocal ones and, after angioplasty, were associated with a worse blood pressure outcome.

Intravascular ultrasound provides additional insights in the hypertensive patients with focal renal artery fibromuscular dysplasia.

To date, few study has defined the exact role or utility of intravascular ultrasound (IVUS) in the diagnosis and treatment of renal artery fibromuscular dysplasia (FMD). We investigated whether using an IVUS would provide additional insights in the hypertensive patients with focal renal artery FMD. A prospective, observational study, including all patients with focal renal artery FMD admitted to the Ruijin hospital during 6 consecutive years (2015-2021). Based on IVUS imaging, focal FMD patients were classified as two subtypes: intima-media thickening (IMT) and negative remodeling (NR) of the whole vessel. A total of 36 consecutive patients (24 ± 7, 13-39 years) with focal renal artery FMD were enrolled. Angiographic unifocal type was present in 22 (61.1%) patients and tubular type was present in 14 (38.9%) patients. Among 22 patients with unifocal, IVUS showed that 18 (81.8%) had IMT and 4 (18.2%) had NR. 14 patients with tubular, IVUS showed 3 (21.4%) had IMT and 11 (78.6%) had NR. No difference in age of onset, gender, BMI, initial BP levels were found between IMT and NR subtypes. However, hypertension cure rates of short-term (48 h after angioplasty) (76.2% vs. 26.7%, p = 0.004) and long-term (1-6years) (90.5% vs. 20.0%, p < 0.001) were higher in patients with IMT than in those with NR subtype. In present study, we described a new classification of focal renal artery FMD into IMT or NR subtype based on IVUS. Renal FMD Patients with IMT subtype were more likely to achieve cure of hypertension. We investigated whether using an IVUS would provide additional insights in the hypertensive patients with focal renal artery FMD. A new classification of focal renal artery FMD into IMT or NR subtype based on IVUS was described. Renal FMD Patients with IMT subtype were more likely to achieve cure of hypertension.

A Retrospective Cohort Study of Cerebrovascular Fibromuscular Dysplasia.

BACKGROUND: Fibromuscular dysplasia (FMD) is a rare vasculopathy for which limited data are available particularly from Europe. Our aim was to study the clinical characteristics of a regional cohort of carotid fibromuscular dysplasia patients to assess their clinical outcomes and the rate of vascular complications. METHODS: A retrospective cohort study of all cases of carotid/cerebrovascular FMD presenting to our regional vascular service (catchment population approximately 2 million), between 1998 and 2020. Imaging reports and patient case notes were screened using the keywords "FMD", "Fibromuscular Dysplasia", and "carotid". From case-note and imaging review, all relevant clinical data were extracted and the anatomical extent of vascular disease recorded. RESULTS: Eighty six patients with a diagnosis of cerebrovascular fibromuscular dysplasia were identified on imaging (31 computed tomography angiography, 46 magnetic resonance angiography, and 9 digital subtraction angiography) by a neurovascular radiologist. The mean age was 64 years, 78 (90%) patients were female, and 45/59 (75%) were Caucasian. Presenting clinical syndromes were Stroke/transient ischemic attack in 54 (63%) patients, symptomatic intracranial aneurysm in 6 (10%), and other neurological symptoms (headache/migraine, tinnitus) in 14 (16%), with 11 (13%) presenting incidentally. Six patients (7%) had a positive family history of FMD (2 patients) or other cerebrovascular event (4 patients: carotid dissection, intracerebral bleed, or stroke). Eight patients (9%) had a known or suspected hereditary connective tissue disorder (2 Ehlers-Danlos syndrome). Involved vessels were as follows: Carotid (mainly extracranial) in 79 (92%), vertebral 19 (22%), and a combination of these in 15 (17%) patients. Fifty eight (67%) patients had bilateral disease. Cerebrovascular complications were observed in 35 (41%) patients as follows: carotid dissection 11 (23%), carotid stenosis or occlusion 8 (9%), carotid aneurysm 8 (9%), cerebral aneurysm 9 (11%), vertebral aneurysm/dissection 2 (2%), and carotid-cavernous fistula 2 (2%). Of the 22 patients who had extracranial imaging, 14 (60%) had FMD affecting other beds-renal artery in 8 (36%) patients, other visceral arteries in 4 (18%), and aorta in 2 (9%). In addition, 4 (18%) patients had aneurysm or dissection affecting renal, splenic, and lower limb arteries. Overall, 67 (80%) patients had FMD affecting more than 1 vessel and 50 (58%) had multisite FMD (>/ = 2 vascular beds involved). Fifty nine (68%) patients were managed conservatively on close surveillance. Nineteen (21%) patients required carotid/cerebrovascular intervention and 9 (10%) required vascular intervention at other sites. Recurrent cerebrovascular events (stroke/transient ischemic attack, symptomatic Berry aneurysm) were seen in 20 (23%) patients. Overall mortality was 7% over a median follow-up period of 47 months. CONCLUSIONS: Carotid FMD patients have a high rate of multisite involvement, extracerebral vascular complications, and evidence of hereditary vasculopathy, requiring careful screening and surveillance.