Fibromuscular disease of the renal artery: a new histopathologic classification

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.

The management of pediatric renovascular hypertension: a single center experience and review of the literature

INTRODUCTION

Renal artery occlusive disease is poorly characterized in children; treatments include medications, endovascular techniques, and surgery. We aimed to describe the course of renovascular hypertension (RVH), its treatments and outcomes.

METHODS

We performed literature review and retrospective review (1993-2014) of children with renovascular hypertension at our institution. Response to treatment was defined by National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents at most-recent follow-up.

RESULTS

We identified 39 patients with RVH. 54% (n=21) were male, with mean age of 6.93 ± 5.27 years. Most underwent endovascular treatment (n=17), with medication alone (n=12) and surgery (n=10) less commonly utilized. Endovascular treatment resulted in 18% cure, 65% improvement and 18% failure; surgery resulted in 30% cure, 50% improvement and 20% failure. Medication alone resulted in 0% cure, 75% improvement and 25% failure. 24% with endovascular treatment required secondary endovascular intervention; 18% required secondary surgery. 20% of patients who underwent initial surgery required reoperation for re-stenosis. Mean follow-up was 52.2 ± 58.4 months.

CONCLUSIONS

RVH treatment in children includes medications, surgical or endovascular approaches, with all resulting in combined 79% improvement in or cure rates. A multidisciplinary approach and individualized patient management are critical to optimize outcomes.

TYPE OF STUDY

Retrospective comparative study LEVEL OF EVIDENCE: Level III.

Diagnosis and management of fibromuscular dysplasia and segmental arterial mediolysis in gastroenterology field: A mini-review

The vascular diseases including aneurysm, occlusion, and thromboses in the mesenteric lesions could cause severe symptoms and appropriate diagnosis and treatment are essential for managing patients. With the development and improvement of imaging modalities, diagnostic frequency of these vascular diseases in abdominal lesions is increasing even with the small changes in the vasculatures. Among various vascular diseases, fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases which need to be diagnosed urgently because these diseases could affect various organs and be lethal if the appropriate management is not provided. However, because FMD and SAM are rare, the cause, prevalence, clinical characteristics including the symptoms, findings in the imaging studies, pathological findings, management, and prognoses have not been systematically summarized. Therefore, there have been neither standard diagnostic criteria nor therapeutic methodologies established, to date. To systematically summarize the information and to compare these disease entities, we have summarized the characteristics of FMD and SAM in the gastroenterological regions by reviewing the cases reported thus far. The information summarized will be helpful for physicians treating these patients in an emergency care unit and for the differential diagnosis of other diseases showing severe abdominal pain.

A case of treatable hypertension: fibromuscular dysplasia of renal arteries

Background

Renovascular hypertension accounts for 51–52 % of all cases of hypertension in the general population, but plays a major role in treatable causes for hypertension in the young. This entity consists of renal vascular atherosclerosis (90 %), commonly seen among the elderly population, and renal fibro muscular dysplasia (FMD) (10 %), predominantly seen in the young. The prevalence of clinically significant renal artery fibromuscular dysplasia is 0.4 %.

Case presentation

We present a case of treatable young hypertension in a 29 year old female, who was diagnosed with renovascular hypertension due to fibromuscular dysplasia of the left renal artery. Computed tomographic angiogram revealed significant stenosis of the left main renal artery. Diethylene triamine penta acetic acid renogram showed a small left kidney due to renal artery stenosis. She underwent left sided nephrectomy, and histology revealed features of FMD, after which she achieved full recovery with normalization of blood pressure, and did not require antihypertensive drug treatment.

Conclusions

Fibromuscular dysplasia causing renal artery stenosis, though a rare cause of renovascular hypertension, is essential to be considered in young hypertensives, even in the absence of family history of hypertension. A high index of suspicion is necessary in early diagnosis and prompt treatment, which can result in rapid and complete recovery.

Sudden death due to coronary artery dissection associated with fibromuscular dysplasia revealed by postmortem selective computed tomography coronary angiography: A case report

We present an autopsy case of sudden death due to coronary artery dissection associated with fibromuscular dysplasia (FMD) in a young female patient. Postmortem selective coronary artery computed tomography (CT) angiography revealed dissections of the left anterior descending and left circumflex arteries. These findings were confirmed by subsequent autopsy. Histopathological examination revealed coronary artery FMD, which is considered a risk factor for dissection. To the best of our knowledge, this is the first postmortem radiology-pathology correlation of coronary artery dissection associated with FMD.

European consensus on the diagnosis and management of fibromuscular dysplasia

The main objectives of this expert consensus are to raise awareness about fibromuscular dysplasia, which is more frequent and more often systemic than previously thought and can sometimes have devastating consequences; to provide up-to-date recommendations for the diagnosis, evaluation, and management of the disease; and to identify research priorities. The emphasis has been put on recommendations for daily practice. The main topics covered include definition, classification, diagnosis, and management of fibromuscular dysplasia in adult patients with symptomatic involvement of the renal arteries, supra-aortic trunks, and digestive and peripheral arteries.

Nonatherosclerotic obstructive vascular diseases of the mesenteric and renal arteries

Nonatherosclerotic vascular diseases of the mesenteric and renal arteries are considered to occur less frequently than those caused by occlusive atherosclerotic disease. However, when present, they pose a significant diagnostic and therapeutic challenge. Such disorders include fibromuscular dysplasia, median arcuate ligament syndrome, the renal nutcracker syndrome, and some forms of acute and chronic mesenteric ischemia (embolic and thrombotic). This is a heterogeneous group of disorders with substantial differences in the pathogenesis and diagnostic approaches to these diseases. We provide an overview of the pathogenesis, clinical presentation, diagnosis, and current management of fibromuscular dysplasia, median arcuate ligament syndrome, and the renal nutcracker syndrome.

The United States Registry for Fibromuscular Dysplasia: results in the first 447 patients

BACKGROUND

Fibromuscular dysplasia (FMD), a noninflammatory disease of medium-size arteries, may lead to stenosis, occlusion, dissection, and/or aneurysm. There has been little progress in understanding the epidemiology, pathogenesis, and outcomes since its first description in 1938.

METHODS AND RESULTS

Clinical features, presenting symptoms, and vascular events are reviewed for the first 447 patients enrolled in a national FMD registry from 9 US sites. Vascular beds were imaged selectively based on clinical presentation and local practice. The majority of patients were female (91%) with a mean age at diagnosis of 51.9 (SD 13.4 years; range, 5-83 years). Hypertension, headache, and pulsatile tinnitus were the most common presenting symptoms of the disease. Self-reported family history of stroke (53.5%), aneurysm (23.5%), and sudden death (19.8%) were common, but FMD in first- or second-degree relatives was reported only in 7.3%. FMD was identified in the renal artery in 294 patients, extracranial carotid arteries in 251 patients, and vertebral arteries in 82 patients. A past or presenting history of vascular events were common: 19.2% of patients had a transient ischemic attack or stroke, 19.7% had experienced arterial dissection(s), and 17% of patients had an aneurysm(s). The most frequent indications for therapy were hypertension, aneurysm, and dissection.

CONCLUSIONS

In this registry, FMD occurred primarily in middle-aged women, although it presents across the lifespan. Cerebrovascular FMD occurred as frequently as renal FMD. Although a significant proportion of FMD patients may present with a serious vascular event, many present with nonspecific symptoms and a subsequent delay in diagnosis.

Bilateral renal infarctions complicating fibromuscular dysplasia of renal arteries in a young male

Fibromuscular dysplasia (FMD) is an uncommon disorder, accounting for less than 10% of cases of renal artery stenosis, and typically presenting with hypertension in young women. This article reports the case of a previously healthy 37-year-old man presenting with acute-onset, severe, bilateral flank pain. Initially treated for ureteral colic and urinary tract infection, he was transferred to the nephrology clinic upon recognition of a rising serum creatinine. He was found to have FMD of bilateral renal arteries with a stenotic pattern on the right side and a dissecting aneurysm on the left side with resultant infarctions in both kidneys. On the basis of negative serological markers of vasculitis, a diagnosis of FMD complicated by bilateral renal infarctions was made. A stent was placed to the right stenotic renal artery, which resulted in sufficient lumen patency. No invasive procedure was performed on the other side owing to the complexity of the lesion. After 2.5 years of follow-up, the patient remained in good condition with normal renal function and adequate blood pressure control with dual antihypertensive therapy. Renal infarction complicating FMD of renal arteries is rare in the literature, with most of the cases having causative cardiovascular risk factors including coagulopathy, ischaemic heart disease, atrial fibrillation or structural cardiac abnormalities, none of which was present in this case. In conclusion, FMD may occur in atypical asymmetric presentations causing renal infarctions in both kidneys. Radiological interventions in such cases should focus on stabilizing renal lesions and renal function.

Focal Renal Arterial Fibromuscular Dysplasia Demonstrated via Intravascular Ultrasound Image

A young male suffering from renovascular hypertension was admitted. His initial arteriogram highlighted a focal stenosis of the right renal artery. His intravascular ultrasound (IVUS) revealed increasing medial layer thickness accompanied by a mixture of both high and low echoic materials in this layer. There was also mild thickening of the intimal layer. The diagnosis of medial fibroplasia and intimal fibromuscular dysplasia (FMD) was made. Balloon angioplasty decreased the volume of dysplastic tissue. The IVUS images facilitated both the initial diagnosis of focal renal arterial stenosis and the evaluation of the mechanism of dilatation by angioplasty.

Surgical treatment and long-term outcome of renovascular hypertension in children and adolescents

OBJECTIVES

This article describes the long-term outcome of surgical treatment in children with renovascular hypertension (RVH) over a 40-year period.

DESIGN

Retrospective study.

MATERIALS AND METHODS

Twenty-five consecutive patients, aged 5-21 years, underwent renal artery (RA) repair from 1967 to 1995. The disease consisted of fibromuscular dysplasia in 17 patients, Takayasu's arteritis in 7 and neurofibromatosis type 1 in one patient.

RESULTS

Twenty-nine RAs were repaired. Primary procedures included aortorenal bypass (ARB) with prosthesis in 10 RAs, autologous vein in five or internal iliac artery in four as conduits, direct reimplantation (DR) in four and nephrectomy in two RAs. Immediate graft failure occurred in three patients despite no peri-operative deaths. After a mean follow-up of 24.4 years, seven patients required secondary nephrectomy. Autologous ARB or DR showed better RA patency and fewer chances for secondary nephrectomy than prosthetic ARB. Hypertension was cured or improved in 21 patients. The overall cumulative survival rate at 20 years was 84%. All five deaths, observed a mean of 12.6 years after the initial operation, were attributed to cardiovascular events.

CONCLUSIONS

Surgical treatment, especially autologous ARB or DR, seems to provide durable results for paediatric RVH. Long-term observation and control of hypertension is mandatory.

Fibromuscular dysplasia

Fibromuscular dysplasia (FMD), formerly called fibromuscular fibroplasia, is a group of nonatherosclerotic, noninflammatory arterial diseases that most commonly involve the renal and carotid arteries. The prevalence of symptomatic renal artery FMD is about 4/1000 and the prevalence of cervicocranial FMD is probably half that. Histological classification discriminates three main subtypes, intimal, medial and perimedial, which may be associated in a single patient. Angiographic classification includes the multifocal type, with multiple stenoses and the 'string-of-beads' appearance that is related to medial FMD, and tubular and focal types, which are not clearly related to specific histological lesions. Renovascular hypertension is the most common manifestation of renal artery FMD. Multifocal stenoses with the 'string-of-beads' appearance are observed at angiography in more than 80% of cases, mostly in women aged between 30 and 50 years; they generally involve the middle and distal two-thirds of the main renal artery and in some case also renal artery branches. Cervicocranial FMD can be complicated by dissection with headache, Horner's syndrome or stroke, or can be associated with intracerebral aneurysms with a risk of subarachnoid or intracerebral hemorrhage. The etiology of FMD is unknown, although various hormonal and mechanical factors have been suggested. Subclinical lesions are found at arterial sites distant from the stenotic arteries, and this suggests that FMD is a systemic arterial disease. It appears to be familial in 10% of cases. Noninvasive diagnostic tests include, in increasing order of accuracy, ultrasonography, magnetic resonance angiography and computed tomography angiography. The gold standard for diagnosing FMD is catheter angiography, but this invasive procedure is only used for patients in whom it is clinically pertinent to proceed with revascularization during the same procedure. Differential diagnosis include atherosclerotic stenoses and stenoses associated with vascular Ehlers-Danlos and Williams' syndromes, and type 1 neurofibromatosis. Management of cases with renovascular hypertension includes antihypertensive therapy, percutaneous angioplasty of severe stenoses, and reconstructive surgery in cases with complex FMD that extends to segmental arteries. The therapeutic options for securing ruptured intracerebral aneurysms are microvascular neurosurgical clipping and endovascular coiling. Stenosis progression in renal artery FMD is slow and rarely leads to ischemic renal failure.

Fibromuscular Dysplasia-Related Renal Artery Stenosis Associated with Aneurysm: Successive Endovascular Therapy

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory vascular disease. FMD of the renal arteries is one of the leading causes of curable hypertension. The simultaneous occurrence of FMD and renal artery aneurysm has been described previously. In this case, we present a fibrodysplastic lesion and an aneurysm in a renal artery treated with a percutaneous transluminal angioplasty and coil embolization.

Cerebrovascular complications of fibromuscular dysplasia

Patients with cerebral ischemia or hemorrhage due to fibromuscular dysplasia (FMD) should be admitted to a monitored hospital bed and receive supportive stroke care. Based on our personal clinical experience, we recommend antiplatelet agents for future stroke prevention in patients with symptomatic FMD. In patients with watershed stroke due to hemodynamically significant FMD, our opinion is that hypertensive, hypervolemic therapy should be initiated immediately. Additionally, we suggest that potential revascularization therapies, such as intraoperative or primary percutaneous angioplasty, should be discussed.

Fibromuscular dysplasia: when is intervention warranted?

Fibromuscular dysplasia is a multifactorial arteriopathy that primarily affects small and medium-sized arteries. It is most common in the renal and internal carotid arteries. Pathological classification is based on the arterial wall layer most significantly involved. The natural history and incidence of asymptomatic disease is unknown. The most common lesions become symptomatic as a high-grade stenosis producing renovascular hypertension or as an embolic source for the cerebral circulation. Treatment is reserved for symptomatic lesions. Most simple lesions are effectively treated by catheter-based intervention. Surgical therapy is warranted for more complex lesions. Both produce durable, long-term results.

Unusual petal-like fibromuscular dysplasia as a cause of acute abdomen and circulatory shock

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory segmental arterial occlusive disorder that involves primarily the renal and carotid arteries, and less often the coronary, iliac, and visceral arteries. We report the case of 78-year-old Japanese woman who presented with acute abdomen complicated by shock. Autopsy revealed hemorrhagic necrosis of the small intestine due to severe narrowing of the mesenteric arteries. Histologically, smooth muscles showed in-bundle hyperplasia surrounding the adventitia together with medial and perimedial fibrodysplasia of these arteries, forming the characteristic petal-like appearance of FMD. No occlusive thrombus was observed. Further, another medial fibrodysplasia type of FMD was also seen in the renal and left circumflex coronary arteries. Unusual proliferation of smooth muscles resulted in the petal-like atypical FMD at the superior mesenteric artery.

Ex vivo repair of a large renal artery aneurysm and associated arteriovenous fistula

The development of a renal artery to vein arteriovenous fistula due to a large extraparenchymal renal artery aneurysm is uncommon. Previous surgical experience with this entity is limited. Based on the existing surgical literature, nephrectomy has been the treatment of choice. We report preservation of the kidney by surgical correction of this entity using ex vivo "bench" repair in a middle-aged female with fibromuscular dysplasia of the renal artery. The technique, results, and recommendations for surgical management are discussed.

Fibromuscular dysplasia

Fibromuscular dysplasia is an uncommon angiopathy that occurs in young to middle-aged, predominately female individuals. The disease consists of a heterogeneous group of histologic changes, which ultimately lead to arterial narrowing. Clinical manifestations reflect the arterial bed involved, most commonly hypertension (renal) and stroke (carotid). Fibromuscular dysplasia is a pathologic diagnosis, but the characteristic changes seen on an angiogram can be used to make the diagnosis in the appropriate clinical setting. This noninflammatory disease is a common mimic of vasculitis. A very limited amount of new literature has been published in the past year about this relatively uncommon condition.