Renal fibromuscular dysplasia

Renal artery fibromuscular dysplasia is a noninflammatory, nonatherosclerotic vasculopathy that can affect renal arteries at various degrees with different severity. The etiology is still unknown, but there is a strong belief that a genetic disorder is the main cause for the pathogenesis of this disease. The main presentation is a sudden onset of recalcitrant hypertension at a young age, which is usually resistant to medical treatment. Once renal artery fibromuscular dysplasia is suspected, several diagnostic tools are available to make an accurate diagnosis. The advent of minimally invasive interventions has revolutionized the options for treatment. This update should provide the clinician with a base understanding of available evidence for diagnosing and treating renal artery fibromuscular dysplasia.     

Fibromuscular dysplasia associated with simultaneous spontaneous dissection of four peripheral arteries in a 30-year-old man

A 30-year-old man had a sudden bout of severe abdominal pain. An enhanced computed tomographic scan revealed dissections of the celiac artery, superior mesenteric artery, left renal artery, and right external iliac artery; stenosis of the right renal artery; and left kidney infarction. After careful evaluation, the patient was diagnosed with fibromuscular dysplasia (medial dysplasia), based on the findings obtained from the enhanced computed tomographic scan. This case is extremely rare because fibromuscular dysplasia occurred concurrently with simultaneous spontaneous dissections of four peripheral arteries in a young man.     

Renal Artery Aneurysm Secondary to Fibromuscular Dysplasia in a Young Patient

An 8-year-old male was found on routine physical examination to have a blood pressure of 220/110. Renal angiography demonstrated bilateral renal artery stenosis and an aneurysm of the distal left renal artery with branch involvement. At operation, the left renal artery stenosis and aneurysm was repaired by ex vivo arterial reconstruction and autotransplantation of the kidney. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis in children over 1 year of age and can in rare cases be associated with the development of renal artery aneurysms. In complex cases of renal artery stenosis with involvement of renal artery branches, ex vivo repair and orthotopic autotransplantation is an excellent approach for surgical management.Presented at the Twenty-second Annual Meeting of the Southern California Vascular Surgery Society, La Jolla, CA, April 30-May 2, 2004.     

Renal infarction secondary to fibrous dysplasia and aneurysm formation of renal artery

We report a case of a previously healthy forty-year-old man with bilateral renal artery stenosis secondary to bilateral medial fibrous dysplasia. He was additionally found to have a dissecting aneurysm of the left upper renal artery branch with resultant infarction of the upper and middle pole renal segments. We believe renal infarction secondary to medial fibrous dysplasia with occlusion of the renal artery associated with a dissecting aneurysm has not been reported, and we report the first such case. A multimodality treatment approach was utilized.     

Asymptomatic renal infarction, due to fibromuscular dysplasia, in a young woman with 11 years of follow-up

We report a 27-year-old woman with renovascular hypertension, renal infarction, and hepatic artery aneurysm due to fibromuscular dysplasia. The patient was first noted to have renal artery aneurysm and hepatic artery aneurysm at the age of 17. The renal infarction was asymptomatic and was incidentally detected by magnetic resonance imaging (MRI) examination. Because of the rather peripheral location of the aneurysms, percutaneous transluminal renal artery angioplasty was considered inappropriate. This case suggests the need for long-term and periodical follow-up of patients with fibromuscular dysplasia.     

Percutaneous transluminal angioplasty for renovascular hypertension in children

Percutaneous transluminal angioplasty (PTA) has been developed over the past 8 years as an alternative to reconstructive surgery for renovascular hypertension. We report three cases and review the use of PTA in children with renal artery stenosis. At least 37 cases of PTA have been reported in patients whose ages ranged from 1.3 to 17 years (mean 10 years). Of these, 10 had fibromuscular dysplasia; 13 unspecified unilateral renal artery stenosis; 4 bilateral stenosis; 4 neurofibromatosis; 4 renal transplant; 1 atherosclerosis; and 1 postsurgical stenosis. Nine of 10 patients with fibromuscular dysplasia were cured and 3 of 4 with renal transplant arterial stenosis were cured or improved. There were 11 failures of PTA, including all 4 patients with neurofibromatosis and 1 with transplant arterial stenosis. We conclude that PTA is the treatment of choice for children with hypertension due to fibromuscular dysplasia and should be attempted for stenosis of the transplanted renal artery. Other lesions resulting in renal artery stenosis may not be as amenable to dilation and should be considered on an individual basis.R. L. Chevalier is an Established Investigator of the American Heart Association     

An unusual case of fibromuscular dysplasia

The case of a patient with abdominal angina due to fibromuscular dysplasia is described. Arteriography revealed dysplasia of both renal arteries and occlusion at their origins of both coeliac and mesenteric arteries. Digital subtraction angiography later showed fibromuscular dysplasia of both carotid artery systems. An unusually long right internal iliac artery allowed it to be anastomosed to the superior mesenteric artery. Follow-up studies have confirmed patency of this reconstruction.     

Donors with renal artery stenosis: fit to donate

Kidney donation from hypertensive donors is now an accepted norm in live related kidney transplantation. The use of hypertensive donors with renal artery stenosis due to atherosclerosis and fibromuscular dysplasia is still debated. The prime concern is about the deleterious effect of hypertension on the donor and the risk of recurrence of such lesions in the solitary kidney. Even as the response of atherosclerotic renal artery stenosis to revascularisation is unpredictable, there is an improvement in blood pressure following revascularisation of kidneys with fibro-muscular dysplasia. The first use of such kidney donors was reported in 1984 and, since then, there have been a few reports of successful use of kidneys from donors with renal artery stenosis. We report here two interesting cases of successful transplantation of kidneys from live related kidney donors with hypertension due to renal artery stenosis who became normotensive with good graft function in the recipient. We conclude that moderately hypertensive donors with renal artery stenosis are fit to donate.     

Prognostic significance of intrarenal resistance indices in patients with renal artery interventions: a preliminary duplex sonographic study

No non-invasive test can predict the clinical outcome of renal revascularization procedures. Because duplex sonographic measurements of intrarenal flow patterns reflect the resistance to flow within the kidney, the prognostic value of the cortical end-diastolic to peak systolic (d/s) velocity ratio was investigated in patients undergoing intervention for renal artery stenosis. The clinical and duplex sonographic data on 32 patients with 35 interventions (30 percutaneous transluminal angioplasties and five operations) on 42 renal artery sides were analysed. Twenty-three patients had atherosclerotic renal artery stenosis and nine patients had fibromuscular dysplasia resulting in ≥60% renal artery stenosis. Measurements of the renal to aortic velocity ratio and cortical d/s ratio were performed before and after intervention. In the atherosclerotic patients, three interventions were clinically and technically successful, eight were technically successful but clinical failures, and 14 were clinically and technically unsuccessful. In the fibromuscular dysplasia patients, eight interventions were clinically and technically successful, and two were clinically and technically unsuccessful. The difference between the corresponding d/s ratios for atherosclerotic and fibromuscular dysplasia sides was significant on both the treated and not-treated sides (P < 0.02, two-tailed unpaired t-test). None of the 11 clinically successful procedures had a d/s ratio below 0.3, compared with seven values below 0.3 in the 24 clinically unsuccessful interventions (P = 0.05, one-tailed Fisher's exact test). It is concluded that: (1), a d/s ratio below 0.3 correlates with clinical failure in subsequent treatment of hypertension by renal revascularization, while a value above 0.3 has no prognostic significance; (2), despite technical success, not all atherosclerotic patients have clinical success from renal artery interventions; (3), in fibromuscular dysplasia patients, all clinical failures of renal artery interventions are associated with technical failures; and (4), the difference in d/s ratio between atherosclerotic and fibromuscular dysplasia patients may be a consequence of the more advanced age, longer duration of hypertension and additional risk factors in atherosclerotic patients.     

Rapid Progression of Native Renal Artery Fibromuscular Dysplasia Following Kidney Donation

Fibromuscular dysplasia is the second commonest anatomical abnormality apart from multiple renal arteries in the potential live donors. Pretransplant evaluation of the donors may include an angiography to evaluate the renal arteries, and failure to recognize renal arterial stenosis, particularly fibromuscular dysplasia, by noninvasive methods may eventually lead to hypertension and ischemic renal failure. We report a case of fibromuscular dysplasia that was undetected by computed tomographic angiography prior to donation. One year after kidney donation, it rapidly progressed to severe symptomatic stenosis with hypertension and acute renal failure. Following renal artery angioplasty, her blood pressure normalized over a period of 2 weeks without any need for antihypertensive medications and the serum creatinine returned to her baseline. The acceptability of renal donors with fibromuscular dysplasia depends on the age, race and the availability of the other suitable donors. Mild fibromuscular dysplasia in a normotensive potential renal donor cannot be considered a benign condition. Such donors need regular follow-up postdonation for timely detection and treatment.     

Novel technique for treatment of a renal artery occlusion in a child with neurofibromatosis: a combined endovascular and laparoscopic approach

Neurofibromatosis is associated with mid-aortic dysplasia, renal artery aneurysms and renal artery ostial stenosis, or occlusions in about 1% of cases. We describe a novel approach to recanalize an occluded renal artery in a 10-year-old girl with neurofibromatosis and difficulty in pharmacologically controlling her hypertension. Normally, when reconstruction is required, an open operative technique is used. We report on the combined use of laparoscopic exposure and percutaneous retrograde puncture of the occluded renal artery, which could be recanalized and stented. The pros and cons of this new approach are discussed.     

Renovascular hypertension: a case of intimal fibroplasia with congenital anomaly of the renal artery

We report a case of renovascular hypertension caused by fibromuscular dysplasia (intimal fibroplasia) with congenital anomaly of the renal artery. Arteriography revealed complete occlusion from the root to the middle of the right renal artery and a collateral artery from the right lumbar artery. Histological examination showed intimal fibroplasia and three arterioles in the intima of the renal artery.     

Fibromuscular dysplasia: noninvasive evaluation of unusual case of renal and mesenteric involvement

Fibromuscular dysplasia is the most common cause of renovascular hypertension in young patients. It primarily involves the renal and carotid arteries, and it is less common in the coronary, iliac, and visceral arteries. Digital subtraction angiography is still the best investigation to determine the location, extent, and complications of renal artery involvement. However, currently, other imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging can reveal these findings noninvasively. We present the case of a 43-year-old woman who presented with high blood pressure and headache. Imaging revealed fibromuscular dysplasia of the renal arteries and the superior mesentery artery.     

Renal arteriovenous fistula associated with fibromuscular dysplasia

A case is reported of a woman with long-standing progressive hypertension and an abdominal bruit who on angiography demonstrated fibromuscular dysplasia of the right renal artery and an arteriovenous fistula in the upper pole of the right kidney. The various causes of renal arteriovenous fistula are reviewed. The relationship of mural aneurysms seen in fibromuscular dysplasia and the formation of arteriovenous fistulas by rupture of these aneurysms is discussed. Review of the English literature indicates a probable causal relationship between fibromuscular dysplasia of the renal arteries and intrarenal arteriovenous fistulas.     

Ask-Upmark kidney with contralateral renal artery fibromuscular dysplasia

A case of Ask-Upmark kidney with coexistent contralateral renal artery fibromuscular dysplasia is presented with detailed light and electron microscopic findings. Both lesions are known to produce renin-mediated hypertension which was corrected in this patient by nephrectomy and contralateral renal artery bypass. Ask-Upmark kidney is briefly reviewed.     

Successful treatment of renovascular hypertension due to fibromuscular dysplasia by intravascular ultrasound-guided atherectomy

A 22-year-old man presented with renovascular hypertension, based on a stenosis of the distal portion of the right renal artery with a "string of beads"-like appearance. An intravascular ultrasound image at the renal artery lesion revealed irregularity of the vascular wall. Directional atherectomy was performed and histopathology of atherectomised tissues showed medial fibroplasia, a common type of fibromuscular dysplasia. After atherectomy his hypertension was markedly improved. We report here a case of renovascular hypertension due to fibromuscular dysplasia, successfully diagnosed and treated with IVUS-guided renal atherectomy.     

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.     

Renal artery stretching and renovascular hypertension. An experimental study

Renovascular hypertension was produced in rabbits by affixing one kidney to the iliac fossa to produce traction on the renal artery. Hyperplasia of the juxtaglomerular apparatus was seen in the kidney in which the renal artery was stretched, whereas no juxtaglomerular apparatus hyperplasia was witnessed in the untouched kidney of rabbits. Whether traction on the renal artery is a sole or contributing factor to the pathogenesis of fibrous dysplasia of the arterial wall remains a moot point.     

Fibromuscular dysplasia of the renal artery: Management and outcome

Renovascular hypertension may be caused by atherosclerotic disease or less commonly by fibromuscular dysplasia (FMD) of the renal arteries. Fibromuscular dysplasia is the commonest cause of renal artery stenosis in the younger age group and affects women predominantly. A review of our clinical database identified all patients with renovascular hypertension. All relevant clinical, biochemical and radiological findings on those with FMD were noted. The outcome of percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery was evaluated. Eight out of 62 (13%) patients with hypertension secondary to renovascular disease had FMD (all female; bilateral in four; mean age at diagnosis 37.6 years; age range 12–70 years). The mean duration of hypertension before the diagnosis of FMD was 3.3 years (range 3 months–10 years). A renal artery bruit was detected in five, hypertensive retinopathy in three and one had mild renal insufficiency. Twelve PTRAs were attempted on 10 stenotic lesions in six women. This cured the hypertension in three, while the other three have required less antihypertensive therapy. Percutaneous transluminal renal angioplasty was complicated by a trivial renal artery dissection in one, and a small upper pole infarction in another. One patient required a repeat PTRA. The other two women presented before the availability of PTRA and had successful reconstructive surgery. Fibromuscular dysplasia was the cause of hypertension in eight out of 62 (13%) patients with renovascular hypertension. Percutaneous transluminal renal angioplasty has shown encouraging results with a low complication rate. If technically feasible, PTRA should be attempted on all patients with FMD of the renal artery.     

Fibromuscular dysplasia of the renal artery: Management and outcome

SUMMARY: Renovascular hypertension may be caused by atherosclerotic disease or less commonly by fibromuscular dysplasia (FMD) of the renal arteries. Fibromuscular dysplasia is the commonest cause of renal artery stenosis in the younger age group and affects women predominantly. A review of our clinical database identified all patients with renovascular hypertension. All relevant clinical, biochemical and radiological findings on those with FMD were noted. the outcome of percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery was evaluated. Eight out of 62 (13%) patients with hypertension secondary to renovascular disease had FMD (all female; bilateral in four; mean age at diagnosis 37.6 years; age range 12–70 years). the mean duration of hypertension before the diagnosis of FMD was 3.3 years (range 3 months-10 years). A renal artery bruit was detected in five, hypertensive retinopathy in three and one had mild renal insufficiency. Twelve PTRAs were attempted on 10 stenotic lesions in six women. This cured the hypertension in three, while the other three have required less antihypertensive therapy. Percutaneous transluminal renal angioplasty was complicated by a trivial renal artery dissection in one, and a small upper pole infarction in another. One patient required a repeat PTRA. the other two women presented before the availability of PTRA and had successful reconstructive surgery. Fibromuscular dysplasia was the cause of hypertension in eight out of 62 (13%) patients with renovascular hypertension. Percutaneous transluminal renal angioplasty has shown encouraging results with a low complication rate. If technically feasible, PTRA should be attempted on all patients with FMD of the renal artery.