Complementary roles of color-flow duplex imaging and intravascular ultrasound in the diagnosis of renal artery fibromuscular dysplasia: should renal arteriography serve as the "gold standard"?

Nonatherosclerotic Renovascular Hypertension

Renovascular hypertension (RVH) is a secondary form of high blood pressure resulting from impaired blood flow to the kidneys with subsequent activation of the renin-angiotensin-aldosterone system. Often, this occurs due to abnormally small, narrowed, or blocked blood vessels supplying one or both kidneys (ie: renal artery occlusive disease) and is correctable. Juxtaglomerular cells release renin in response to decreased pressure, which in turn catalyzes the cleavage of circulating angiotensinogen synthesized by the liver to the decapeptide angiotensin I. Angiotensin-converting enzyme then cleaves angiotensin I to form the octapeptide angiotensin II, a potent vasopressor and the primary effector of renin-induced hypertension. The effects of angiotensin II are mediated by signaling downstream of its receptors. Angiotensin receptor type 1 is a G-protein-coupled receptor that activates vasoconstrictor and mitogenic signaling pathways resulting in peripheral arteriolar vasoconstriction and increased renal tubular reabsorption of sodium and water which promotes intravascular volume expansion. Angiotensin II stimulates the adrenal cortical release of aldosterone, which promotes renal tubular sodium reabsorption, resulting in volume expansion. Angiotensin II acts on glial cells and regions of the brain responsible for blood pressure regulation increasing renal sympathetic activation. Angiotensin II simulates the release of vasopressin from the pituitary which stimulates thirst and water reabsorption from the kidney to expand the intravascular volume and cause peripheral vasoconstriction (increased sympathetic tone). All of these mechanisms coalesce to increase arterial pressure by way of arteriolar constriction, enhanced cardiac output, and the retention of sodium and water.

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.

Intravascular US: Applications in Interventional Radiology

Interventional radiology applications of intravascular US (IVUS) continue to expand, complementing intraprocedural angiography and providing a unique vantage from which to guide endovascular interventions. Vascular pathologic conditions become sonographically visualized rather than inferred from the planar appearance of the opacified vascular lumen. Perivascular targets become sonographically visualized rather than approximated on the basis of fluoroscopic landmarks. The authors introduce broad categories of IVUS catheters, namely radial and side-firing varieties, as well as prevailing options for each and their technical specifications. Common applications within interventional radiology are covered in a systems approach, including deep venous thrombosis, May-Thurner syndrome, nutcracker syndrome, transjugular intrahepatic portosystemic shunts, aortic interventions, peripheral arterial disease, and endovascular or perivascular biopsy. Discussions are accompanied by technical pearls from the authors, and summarized evidence where IVUS has been shown to reduce procedural time, intravascular contrast agent dose, radiation exposure, and morbidity in each space is presented. Finally, emerging applications and future directions are discussed. ^©RSNA, 2022.

Renal artery stenosis

Renal artery stenosis is the most common secondary cause of hypertension and predominantly caused by atherosclerosis. In suspected patients, a non-invasive diagnosis with ultrasound is preferred. Asymptomatic, incidentally found RAS does not require revascularization. In symptomatic patients requiring revascularization, renal artery stenting is the preferred therapy. Selecting appropriate patients for revascularization requires careful consideration of lesion severity and is optimized with a multidisciplinary team. All patients with atherosclerotic RAS should be treated with guideline-directed medical therapy, including hypertension control, diabetes control, statins, antiplatelet therapy, smoking cessation and encouraging activity.

Intravascular Ultrasound in Carotid Web

Background

Carotid web (CaW) is a shelf-like linear filling defect in the posterior aspect of the internal carotid bulb, representing an intimal variant of fibromuscular dysplasia. The diagnosis of CaW is traditionally restricted to digital subtraction angiography (DSA), CT/MR angiography (CTA/MRA), and Duplex ultrasonography. In this series of patients with acute ischemic stroke, we evaluated the potential utility of intravascular ultrasound (IVUS) in further characterizing suspected CaWs.

Methods

This is a case series of three patients with suspected CaW who underwent DSA for treatment or investigation of large vessel occlusion strokes. In all cases the stroke investigation failed to identify an alternative cause, and the stroke etiology was attributed to a symptomatic CaW. The procedure consisted of positioning a guide catheter in the common carotid artery, navigating the IVUS probe distal to the carotid bulb, and then retracting the probe with a manual pullback. The acquired images were then reviewed in an independent workstation

Results

In two of the three cases, IVUS showed an isoechoic-to-hyperechoic focal eccentric area at the posterior carotid bulb, consistent with CaW. The endoluminal protrusion was inconspicuous on IVUS due to the low resolution of ultrasound not allowing a clear differentiation between fibrosis, thrombosis, and atherosclerosis. No abnormalities commonly associated with atherosclerotic disease or dissections were noted. The CaW could not be depicted in the third patient.

Conclusion

The use of IVUS in the diagnosis of CaW may have limited relevance. Continued investigation of other imaging modalities for accurate CaW diagnosis is recommended.

Multimodality imaging of fibromuscular dysplasia

OBJECTIVE

Fibromuscular dysplasia (FMD) is an uncommon non-inflammatory and non-atherosclerotic cause of arterial disease that may result in stenosis, tortuosity, aneurysm, or dissection. The clinical presentation depends on the vascular bed involved and ranges from asymptomatic to multisystem disease and end organ ischemia. The purpose of this article is to review the role of imaging in patients with FMD with an emphasis on renal FMD. The relevant epidemiology, histopathology, imaging techniques, and interpretation of images will be discussed.

CONCLUSION

Renal artery FMD requires a high index of suspicion for accurate and prompt diagnosis and implementation of appropriate therapy. The treatment will vary based on clinical presentation and distribution of involvement. Noninvasive imaging with duplex ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) are reasonable alternatives for the depiction of FMD in comparison to catheter-directed angiography (CA). Patients with FMD are often treated by multispecialty practice including the interventional radiologist.

Nonatherosclerotic PAD: Approach to Exertional Pain in the Lower Extremities

Atherosclerotic peripheral artery disease is the most common cause of intermittent claudication. Nonatherosclerotic peripheral artery disease is a heterogeneous collection of diseases affecting the extracoronary arteries which is not due to atherosclerosis. These diseases include, but are not limited to, popliteal artery entrapment syndrome, cystic adventitial disease, external iliac endofibrosis, and thromboangiitis obliterans. Due to its relatively low prevalence, nonatherosclerotic peripheral artery disease may be misdiagnosed leading to the mismanagement of potentially treatable conditions. The proper and timely diagnosis of these conditions is paramount to the prevention of adverse outcomes as treatments widely vary. The diagnostic approach to patients presenting with intermittent claudication must take into account both atherosclerotic as well as nonatherosclerotic causes of peripheral artery disease making the differential vital to clinical practice.

Optimal management of renal artery fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory angiopathy of unknown cause affecting medium-sized (most commonly renal) arteries and causing renovascular hypertension. The most common medial multifocal type of FMD (with the “string of beads” appearance) is more than four times more prevalent in females than in males. FMD accounts for up to 10% of cases of renovascular hypertension. Compared with patients with atherosclerotic renal artery stenosis, patients with FMD are younger, have fewer risk factors for atherosclerosis, and a lower occurrence of atherosclerosis in other vessels. The etiology is multifactorial, including vessel wall ischemia and smoking, as well as hormonal and genetic factors. Intra-arterial digital subtraction angiography is still the gold standard for exclusion or confirmation of renal artery stenosis caused by FMD, at least in young patients, who more often have lesions in branches of the renal artery. For FMD patients with atherosclerosis and those who are older (>50–55 years), significant renal artery stenosis may be confirmed or excluded with ultrasonography. The FMD lesion is typically truncal or distal, whereas atherosclerotic lesions are more often proximal or ostial. Treatment options are medical, endovascular (percutaneous transluminal renal angioplasty [PTRA]), and surgical. Invasive treatment should be considered when hypertension cannot be controlled with antihypertensive drugs and in patients with impaired renal function or ischemic nephropathy. PTRA has become the treatment of choice and normally yields good results, especially in unifocal disease and young patients. Pressure gradients are normally completely abolished, and there is no indication for stent placement. Surgical revascularization is indicated after PTRA complications; thrombosis, perforation, progressive dissection, repeated PTRA failure or restenosis. Centralization of handling is recommended.

Treatment of hypertension in patients with renal artery stenosis due to fibromuscular dysplasia of the renal arteries

Renal artery stenosis (RAS) from fibromuscular dysplasia (FMD) is an uncommon cause of hypertension that affects mostly women. FMD is a noninflammatory vascular disease that predominantly affects mainly the renal arteries, but can also affect arteries in other vascular territories. The most common type of FMD is the media fibroplasia with the characteristic "string of beads" appearance (80-90%), whereas the two other types, the "intimal" and "adventitial" FMD are much less common accounting for 10% and <5% of cases, respectively. The prevalence of FMD in the general population is not well known. Estimates are derived from screening kidney donors, with a prevalence of about 2.6%. Among patients with renovascular hypertension (RVH), its incidence is about 10%, whereas 80-90% of RVH is due to atherosclerotic renal artery stenosis (ARAS). The treatment of choice of hypertension due to FMD is percutaneous renal angioplasty (PTRA). In contrast, hypertension due to ARAS is not frequently responsive to PTRA. In order to achieve successful control of hypertension in patients with FMD, a combination of PTRA with drugs that block the renin-angiotensin-aldosterone system (RAAS) is often necessary. The purpose of this review was to search the literature for newer diagnostic methods and treatment of FMD. Therefore, a Medline search of the English literature of published papers between 2008 and December 2013 was performed. Of 58 papers reviewed, 19 pertinent papers were selected including, studies, reviews, registries and case reports. The information from these studies together with collateral literature will be discussed in this concise review.

Association between 2 angiographic subtypes of renal artery fibromuscular dysplasia and clinical characteristics

BACKGROUND

Initially based on histology, the diagnosis of renal artery fibromuscular dysplasia (FMD) is now based mostly on angiographic appearance because arterial tissue samples are rarely available. This retrospective cross-sectional study aimed to assess the clinical relevance of a binary angiographic classification of FMD lesions (unifocal or multifocal) based on computed tomographic or magnetic resonance angiography.

METHODS AND RESULTS

Adult patients diagnosed with FMD in a single tertiary care center for hypertension management were identified by screening of electronic files. FMD lesions were reviewed and classified according to computed tomography or magnetic resonance angiography as multifocal if there were at least 2 stenoses in the same arterial segment; otherwise, they were classified as unifocal. Of 337 patients with established renal artery FMD, 276 (82%) were classified as multifocal. Patients with unifocal and multifocal lesions differed significantly in median age at diagnosis of FMD (30 and 49 years) and hypertension (26 and 40 years), sex distribution (female:male ratio, 2:1 and 5:1), initial blood pressure (157/97 and 146/88 mm Hg), current smoking (50% and 26%), prevalence of unilateral renal artery lesions (79% and 38%), presence of kidney asymmetry (33% and 10%), renal revascularization procedures (90% and 35%), and hypertension cure rates in patients who underwent revascularization (54% and 26%).

CONCLUSIONS

A binary angiographic classification into unifocal or multifocal renal artery FMD is straightforward and discriminates 2 groups of patients with different clinical phenotypes.

Clinical features, management, and prognosis of spontaneous coronary artery dissection

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is an acute coronary event of uncertain origin. Clinical features and prognosis remain insufficiently characterized.

METHODS AND RESULTS

A retrospective single-center cohort study identified 87 patients with angiographically confirmed SCAD. Incidence, clinical characteristics, treatment modalities, in-hospital outcomes, and long-term risk of SCAD recurrence or major adverse cardiac events were evaluated. Mean age was 42.6 years; 82% were female. Extreme exertion at SCAD onset was more frequent in men (7 of 16 versus 2 of 71; P<0.001), and postpartum status was observed in 13 of 71 women (18%). Presentation was ST-elevation myocardial infarction in 49%. Multivessel SCAD was found in 23%. Initial conservative management (31 of 87) and coronary artery bypass grafting (7 of 87) were associated with an uncomplicated in-hospital course, whereas percutaneous coronary intervention was complicated by technical failure in 15 of 43 patients (35%) and 1 death. During a median follow-up of 47 months (interquartile range, 18-106 months), SCAD recurred in 15 patients, all female. Estimated 10-year rate of major adverse cardiac events (death, heart failure, myocardial infarction, and SCAD recurrence) was 47%. Fibromuscular dysplasia of the iliac artery was identified incidentally in 8 of 16 femoral angiograms (50%) undertaken before closure device placement and in the carotid arteries of 2 others with carotid dissection.

CONCLUSIONS

SCAD affects a young, predominantly female population, frequently presenting as ST-elevation myocardial infarction. Although in-hospital mortality is low regardless of initial treatment, percutaneous coronary intervention is associated with high rates of complication. Risks of SCAD recurrence and major adverse cardiac events in the long term emphasize the need for close follow-up. Fibromuscular dysplasia is a novel association and potentially causative factor.

Symptomatic fibromuscular dysplasia of the external iliac artery

The aim of this article is to report a case of symptomatic fibromuscular dysplasia (FMD) involving the external iliac arteries (EIAs). An 88-year-old woman was admitted to the vascular service, with a painful right posterior ankle ulcer that had progressively worsened during the course of a month. Her medical history included diabetes and hypertension. Bilateral lower-extremity pulses were absent, and femoral and tibial Doppler waveforms were monophasic. Pelvic and bilateral lower-extremity angiograms were obtained, which revealed findings in both EIAs consistent with a diagnosis of extrarenal FMD. Percutaneous transluminal angioplasty with subsequent stenting of the right EIA was performed, using a self-expanding stent. Completion digital subtraction angiography demonstrated a widely patent right EIA with brisk flow of contrast across the stent. Postprocedural arterial duplex scan showed a biphasic waveform pattern in the common femoral artery. FMD can involve the EIA and be associated with critical limb ischemia. FMD of the EIA responds well to endovascular management.

A unique case of renal artery fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a noninflammatory, nonatherosclerotic disorder resulting in arterial stenosis. Here, a unique case of renal artery FMD (RA FMD) is presented. With the use of angiograpic and intravascular ultrasound (IVUS) imaging modalities, a patient was diagnosed with two distinct types of FMD. Until now, the prevalence of FMD has been underestimated due to limitations in diagnostic modalities. Clinically, the correct identification of RA FMD is essential because these patients have been shown to respond to revascularization therapy with significant improvement in blood pressure whereas renal artery lesions secondary to other etiologies such as atherosclerosis have yet to show the same consistent response. Further, the presence of two subtypes of FMD in a single patient may suggest the possibility of genetic factors that predispose certain vessels to certain subtypes of FMD.

[Renal artery fibromuscular dysplasia]

Fibromuscular dysplasia (FMD) encompasses a heterogeneous group of idiopathic, segmental, nonatherosclerotic diseases of the musculature of arterial walls, leading to the narrowing of small and medium-sized arteries. The most common locations of FMD are renal arteries and carotid arteries. The diagnosis of FMD is made on the "string of beads" appearance of the arteries. The French Health Authority recommends performing a CT scan or an MRA to assess the diagnosis of FMD. A recent meta-analysis showed the cure rates using current definitions of hypertension cure are only 36% and 54% after angioplasty and surgery, respectively.

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.

Assessment of renal artery fibromuscular dysplasia: angiography, intravascular ultrasound (with virtual histology), and pressure wire measurements

Fibromuscular dysplasia (FMD) of the renal arteries is classically associated with secondary hypertension in younger individuals, which may be treatable and even curable by percutaneous transluminal renal angioplasty. Angiography of these renal arteries often displays "beaded" luminal abnormalities. The angiographic findings, however, may not accurately reflect the severity or precise location of the intraluminal obstruction. We present a case of an older individual with longstanding hypertension and FMD, in whom the use of a coronary pressure wire and intravascular ultrasound enabled precise localization and treatment of the hemodynamically significant stenosis. Virtual histology of FMD in the renal vasculature is also reported.

Renovascular hypertension: an update

Renovascular hypertension, the most common remediable cause of elevated blood pressure, is a controversial topic, but most authorities agree on several principles. The absolute risk of renovascular hypertension for a specific patient can be estimated using only clinical information, thereby sparing many patients further expensive and potentially dangerous evaluations. Patients with a high absolute risk of renovascular hypertension should have angiography only if they are willing to undergo revascularization if warranted. A screening test (captopril renography, Doppler ultrasonography, magnetic resonance angiography, or computed tomography) is recommended for those with an intermediate absolute risk. Angioplasty should be offered to patients with fibromuscular dysplasia. Whether intensive medical therapy (including an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker) for atherosclerotic renovascular hypertension is improved by angioplasty plus stent placement may be answered by ongoing studies, the largest of which may be the National Institutes of Health-funded Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial.

Evaluation of the abdominal aorta and the renal arteries with an intracardiac echocardiography probe placed in the inferior vena cava: a feasibility study

BACKGROUND

Ultrasound evaluation of the abdominal aorta and its branches is usually performed transabdominally. Not infrequently, the image quality is suboptimal. Recently, an intracardiac echocardiography probe has become commercially available. These probes are usually inserted intravenously and advanced to the right heart for diagnostic and monitoring purposes during procedures such as atrial septal defect closure and pulmonary vein isolation. Because of the close anatomic relation between the abdominal aorta and the inferior vena cava, we hypothesized that these probes would be useful in the evaluation of the abdominal aorta and the renal arteries.

METHODS

Sixteen patients with normal renal function and no history of hypertension who were undergoing a pulmonary vein isolation procedure or atrial septal defect closure were studied. In each patient, the intracardiac echocardiography probe was inserted in the femoral vein and advanced to the right atrium for the evaluation of the left atrium and the pulmonary veins during the procedure. At the end of the therapeutic procedure, the probe was withdrawn into the inferior vena cava for the evaluation of the aorta and renal arteries.

RESULTS

High-resolution images of the abdominal aorta from the diaphragm to its bifurcation were easily obtained in all patients. These images allowed for the evaluation of arterial size, shape, and blood flow. Both renal arteries were easily visualized in each patient. With the probe in the inferior vena cava, both renal arteries were parallel to the imaging plane and, therefore, accurate measurement of renal blood flow velocity and individual renal blood flow were measured.

Fibromuscular Dysplasia: An Uncommon Cause of Secondary Hypertension

Fibromuscular dysplasia is a noninflammatory vascular disease that commonly affects the distal two thirds of the renal artery and branch vessels, but occasionally involves other arteries. Progression of stenosis occurs in 16%-38% of renal arteries. Although the etiology is unknown, genetic studies suggest a relationship to the angiotensin-converting enzyme I allele. Thin, young Caucasian women without a family history of hypertension are most commonly affected. An abdominal or flank systolic-diastolic bruit is an important clue for the diagnosis. Most noninvasive screening tests are not sensitive or reproducible to be used to rule out renal artery stenosis, but digital subtraction renal angiography usually confirms the diagnosis. Percutaneous renal artery angioplasty is the treatment of choice, but may not result in normalization of blood pressure if diagnosis is delayed. Since restenosis occurs, continued follow-up is necessary.

Fibromuscular dysplasia of renal arteries: Percutaneous revascularization based on hemodynamic assessment with a pressure measurement guidewire

Fibromuscular dysplasia (FMD) leading to renal artery stenosis and hypertension is one of the most common treatable causes of secondary hypertension. However, frequently it can be difficult to judge the anatomical severity of a stenotic lesion with various noninvasive and invasive imaging modalities. We present two patients with poorly controlled hypertension and FMD affecting the renal arteries, in whom there were no anatomically significant stenoses by renal magnetic resonance angiography or selective renal artery angiography. Utilizing a 0.014'' high fidelity micromanometer tipped PressureWire XT (Radi, Reading, MA), to measure intravascular pressure gradients throughout the diseased renal arteries, we identified physiologically significant stenoses, and successfully treated both patients with percutaneous transluminal angioplasty.

Revascularisation of renal artery stenosis caused by fibromuscular dysplasia: effects on blood pressure during 7-year follow-up are influenced by duration of hypertension and branch artery stenosis

Fibromuscular dysplasia (FMD) mainly affects renal arteries. Percutaneous transluminal renal angioplasty (PTRA) and surgery are effective treatments, but long-time follow-up is lacking. Retrospective follow-up for 7.0+/-4.7 years of 69 consecutive patients (age 44+/-13 years) treated for hypertension due to FMD, 59 patients underwent PTRA and eight patients surgery. In two patients no PTRA was performed. Technical success was achieved in 56 (95%) patients undergoing PTRA and all eight undergoing surgery. After successful PTRA, both systolic and diastolic blood pressures (SBP and DBP) had decreased at discharge (from 174+/-33/100+/-13 to 138+/-19/80+/-15 mmHg; P<0.0001), and remained lower at 1 month, 1 year, and last follow-up after 7.0+/-4.7 years (140+/-25/83+/-12 mmHg; P<0.0001). Serum-creatinine had decreased both at 1 year (from 84+/-28 to 75+/-13 micromol/l; P=0.0030) and last follow-up (75+/-16 micromol/l; P=0.0017). The number of antihypertensive drugs decreased (from 2.3+/-1.2 before PTRA to 1.4+/-1.3 at discharge and at 1 month; P<0.0001, and 1.6+/-1.5 at last follow-up; P=0.0011). SBP decreased more after PTRA among patients with FMD only in the main renal artery than in those with branch artery involvement (43+/-29 vs 20+/-41 mmHg; P=0.0198). Beneficial effects on BP, creatinine and antihypertensive drugs also occurred after surgery. Patients on antihypertensive drugs at last follow-up had longer hypertension duration before PTRA than those without (5.9+/-7.7 vs 1.8+/-4.1 years; P=0.0349). Cure was achieved in 16 (24%), improvement in another 26(39%), and benefit in 42(63%). In conclusion, renal artery FMD, PTRA and surgery have beneficial long-term effects, negatively affected by hypertension duration and branch artery involvement.

Renal fibromuscular dysplasia in elderly persons

Renal artery stenosis (RAS) is a significant cause of secondary hypertension, the progression of which can lead to renal insufficiency, uncontrolled hypertension, and even end-stage renal disease. The 2 most common forms of RAS are atherosclerotic renovascular disease and fibromuscular dysplasia (FMD). Atherosclerosis accounts for 90% of all cases of RAS and generally affects an elderly population. Conversely, FMD accounts for approximately 10% of all RAS cases and is described as affecting a younger population. Four cases of FMD in individuals older than 70 years are presented, in a period of 1 year at 1 facility. This case series calls into question the previously reported low prevalence of FMD in elderly persons. It is conceivable that renal artery investigation might be denied an elderly patient thought to have atherosclerotic disease. Because conventional angioplasty is considered the treatment of choice for patients with FMD because of the high response rate for uncontrolled hypertension, the prevalence of FMD in the elderly population should be reevaluated to detect and treat this population accordingly.

Fibromuscular dysplasia

The most common clinical manifestations of fibromuscular dysplasia (FMD) are hypertension due to renal artery involvement and transient ischemic attack or stroke due to carotid or vertebral artery involvement. Patients with renal artery FMD and hypertension should undergo primary angioplasty with the goal of curing the hypertension. If the blood pressure fails to normalize following angioplasty, the physician should institute antihypertensive medications according to the recommendations of the Joint National Committee on the Prevention, Detection, and Treatment of High Blood Pressure VII. In patients with cerebrovascular FMD, antiplatelet agents represent the cornerstone of therapy. Percutaneous angioplasty has emerged as the preferred treatment for symptomatic cerebrovascular FMD.