Renovascular hypertension associated with neurofibromatosis: a case report

Although vascular involvement in type 1 neurofibromatosis (NF1) is rare, it may lead to renal artery stenosis and renovascular hypertension (RVH). RVH may be treated using antihypertensive drugs, percutaneous transluminal renal angioplasty (PTRA), surgical reconstruction of the renal artery, or nefrectomy. In NF1 the results of PTRA are less predictable than in cases of fibromuscular dysplasia and atherosclerosis. We report a case of RVH associated with NF1. Despite administration of multiple antihypertensive drugs blood pressure remained uncontrolled. Selective left renal arteriography demonstrated two consecutive high-grade stenotic lesions with post-stenotic aneurysmal dilatation treated successfully with balloon dilatation. During the ensuing 2 year follow up complete normalization of blood pressure was observed. This case illustrates that endovascular therapy may be beneficial and should be considered a reasonable first option in these patients. However vascular involvement in NF may be progressive and therefore always requires continuing follow up.     

Percutaneous transluminal angioplasty in the treatment of renovascular hypertension

In this study we report our experience in 74 patients with hypertension and renal artery stenosis (42 with atherosclerotic stenosis, 32 with fibromuscular dysplasia) who were followed-up for a mean observation period of 21.7 months after percutaneous transluminal angioplasty (PTA). Stenosis was unilateral in 45 cases, bilateral in 16 and located in the renal artery of a solitary functioning kidney in 13 cases. Ostial involvement was observed in 26 cases. A total of 24 patients showed impaired renal function before PTA. Overall results for BP control were 8 cures (13%), 29 improvements (48%) and 24 (39%) who remained unchanged. Five of the 24 patients (21%) with impaired renal function showed improvement with a decrease in serum creatinine levels of more than 30%. Complications of PTA were rare, being limited to two haematomas at the puncture site which resolved spontaneously. These results emphasize that PTA, an easily repeatable procedure of relatively low risk, short hospital stay and low cost, is a first choice technique in the management of renovascular hypertension.     

Orthostatic hypertension due to coexistence of renal fibromuscular dysplasia and nephroptosis

A 42-year-old woman presented with orthostatic hypertension. Increased plasma renin activity was noted and blood pressure rose gradually with standing. Selective renal arteriography indicated narrowing of the distal portion of the right renal artery and poststenotic dilatation and signs of arterial stenosis due to fibromuscular dysplasia. Greater arterial narrowing resulted from tortion due to nephroptosis brought about by excessive renin secretion. Thus, both renal arterial stenosis and nephroptosis were considered responsible for the present orthostatic hypertension. Percutaneous transluminal renal angioplasty was found very effective for normalizing standing blood pressure and renal blood flow.     

Autotransplantation and stent implantation for bilateral renal artery fibromuscular dysplasia.

A 36-yr-old male was found to have renovascular hypertension due to an occluded right renal artery and 70% stenosis in the left renal artery, caused by fibromuscular dysplasia. The right kidney was supplied by collateral blood flow, and secreted more renin than the left kidney. Two differential therapeutic approaches were taken: autotransplantation for the right kidney and percutaneous transluminal renal angioplasty followed by stent implantation for the left. The renovascular hypertension was treated with these therapies, preserving renal function in this patient.     

Nierenarterienstenosen

Renal artery stenosis can be caused by a variety of diseases but atherosclerotic renal artery stenosis (ARAS 60–90%) and fibromuscular dysplasia are the two most frequent entities. Only 1% of hypertensive patients develop renal artery stenosis and correction of stenosis will not automatically improve blood pressure or renal function. If such an improvement occurs, renovascular hypertension or renovascular azotemia can be retrospectively diagnosed. Up to now randomized controlled trials have failed to show a benefit of angioplasty in patients with ARAS compared to medicinal treatment alone. All patients with renal artery stenosis should receive optimal medical treatment to treat hypertension and prevent progression of atherosclerotic disease. Expert opinions based on uncontrolled trials recommend angioplasty in patients with ARAS and unexplained flash pulmonary edema, refractory heart failure, uncontrollable hypertension and progressive renal failure. The results of further randomized controlled trials are eagerly awaited.     

Percutaneous transluminal renal angioplasty in the treatment of unilateral atherosclerotic renovascular hypertension

Thirteen patients with severe, unilateral, atherosclerotic renovascular hypertension were treated with percutaneous transluminal renal angioplasty. The procedure produced wide patency of the stenosed vessel in 10 patients and partial dilatation in the remaining three. All patients exhibited a beneficial response in their hypertension; at latest follow-up, ranging from two to eighteen months, all patients were normotensive, four in the complete absence of any antihypertensive medication and the remaining nine while taking substantially less medication than before. Suppression of the differential renal-vein renin ratio was also documented.In one patient follow-up angiography, performed after seven months because of deterioration in renal function, revealed an occluded renal artery. Complications that were encountered included two small, segmental renal infarcts, three episodes of nonoliguric, presumably radiocontrast-induced, acute renal insufficiency and a soft-tissue hematoma that occurred one month after the procedure and was due to excessive anticoagulation. Percutaneous transluminal renal angioplasty may be an effective modality in the management of unilateral, atherosclerotic renovascular hypertension.     

Percutaneous transluminal renal angioplasty in nonatherosclerotic renovascular hypertension. Long-term results

Nineteen stenotic arteries in 16 patients with severe renovascular hypertension of nonatherosclerotic nature (fibromuscular dysplasia in 13, neurofibromatosis in 3) were treated with percutaneous transluminal renal angioplasty. The procedure was technically successful in 12 of 14 (86%) stenoses in the fibromuscular dysplasia subgroup but in only one of five (20%) lesions in the neurofibromatosis subgroup. Hypertension was abated (3 patients) or disappeared (8 patients) in 11 of the 12 (92%) patients with fibromuscular dysplasia who had a technically successful angioplasty, an effect that was sustained at latest follow-up (avg, 37 mo; range, 10-73 mo). The only complication encountered was a retroperitoneal hematoma that resolved uneventfully. Coupled with those from other centers, the results of the present study indicate that angioplasty offers a strong potential for curability in patients with renovascular hypertension caused by fibromuscular dysplasia and that percutaneous transluminal renal angioplasty should be considered the treatment of choice for the initial management of all patients with fibromuscular renovascular hypertension.     

Percutaneous Transluminal Renal Angioplasty in the Treatment of Renovascular Hypertension in Children

We report five young patients who underwent percutaneous transluminal renal angioplasty (PTRA) for the treatment of hypertension related to renal artery stenosis. Four had fibromuscular disease and one had probable Takajasu's arteritis; two had solitary kidneys. Following PTRA, a prompt decrease in blood pressure was observed in all patients. Further, four of five patients long after PTRA remained normotensive, and in all patients plasma renin levels declined. These results indicate that PTRA can be a safe and effective alternative to surgery in the treatment of renovascular hypertension in childhood.     

Identification of Potential Regulatory Regions in the Renin Gene

Circadian blood pressure (BP) variation were studied in patients with renovascular hypertension (RVH) and primary aldosteronism (PA). Ambulatory BP (ABP) was monitored every 5 min for 24 hrs in a ward setting in 23 patients with PA and 17 patients with RVH (13 patients with unilateral renal arterial stenosis and 4 with bilateral stenosis). In patients with RVH, ABP was monitored before and after treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty. Plasma renin activity (PRA) was high before percutaneous transluminal angioplasty in almost all patients with RVH and low in those with PA. Ordinary circadian BP variation, i.e. nocturnal fall and diurnal rise in BP, was confirmed in the patients with unilateral or bilateral renal artery stenosis. Percutaneous transluminal angioplasty successfully normalized both BP and PRA in those with RVH. Normal circadian BP variation was observed in those with RVH before the treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty as well as during treatment with the former and after treatment with the latter. Circadian BP variation in the patients with RVH was affected by the pathogenesis of renal artery stenosis alone, i.e, fibromuscular hyperplasia and atherosclerosis; with fibromuscular hyperplasia normal circadian BP variation was observed, while with atherosclerosis, nocturnal BP fall was restricted or eliminated. Circadian BP variation in those with PA before and after excision of adrenal adenoma was essentially similar to that in normal subjects and essential hypertensive patients. From these it seems that in patients with RVH or PA, circadian BP variation is not affected by hypertension per se or by pathogenesis of hypertension.     

How to diagnose,how to treat: renal artery stenosis-diagnosis and management

Renal artery stenosis is considered to be one of the more frequent causes of secondary arterial hypertension. Through its progression renal artery stenosis can cause renal insufficiency, uncontrolled hypertension, and increased cardiovascular morbidity. A thorough clinical examination and the presence of a typical abdominal bruit may provide helpful hints to identify hypertensive patients with possible renal artery stenosis. Testing for renovascular hypertension includes renal artery imaging, assessment of its functional significance, and evaluation for possible revascularization. Renal artery stenosis secondary to fibromuscular dysplasia should be mechanically corrected. For atherosclerotic renal artery stenosis, medical management can be attempted so long as it does not cause a decline of kidney function. In patients who are candidates for renovascular revascularization, surgical intervention can be helpful in improving blood pressure control and possibly halting the progression of renal failure. Randomized controlled trials comparing direct stenting with other surgical methods are necessary to define the best revascularization strategy in patients with renovascular hypertension. A careful follow-up study after renal artery revascularization should evaluate possible benefits in halting the deterioration of chronic renal insufficiency.     

Congenital solitary kidney with renovascular hypertension diagnosed by means of captopril-enhanced renography and magnetic resonance angiography

A 24 year-old woman had a congenital solitary kidney with renovascular hypertension due to fibromuscular dysplasia. She had been treated as having essential hypertension until she developed preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome at 28 weeks of gestation. Plasma renin activity and captopril test results did not indicate any abnormalities. However, renography revealed captopril-induced deterioration. Magnetic resonance angiography was also useful to detect renal artery stenosis. These findings were confirmed by renal angiography. After successful percutaneous transluminal renal angioplasty, her blood pressure and the pattern of captopril renography normalized.     

Renal Artery Stenosis: Diagnosis and Management

Renal artery stenosis is considered to be one of the more frequent causes of secondary arterial hypertension. Through its progression renal artery stenosis can cause renal insufficiency, uncontrolled hypertension, and increased cardiovascular morbidity. A thorough clinical examination and the presence of a typical abdominal bruit may provide helpful hints to identify hypertensive patients with possible renal artery stenosis. Testing for renovascular hypertension includes renal artery imaging, assessment of its functional significance, and evaluation for possible revascularization. Renal artery stenosis secondary to fibromuscular dysplasia should be mechanically corrected. For atherosclerotic renal artery stenosis, medical management can be attempted so long as it does not cause a decline of kidney function. In patients who are candidates for renovascular revascularization, surgical intervention can be helpful in improving blood pressure control and possibly halting the progression of renal failure. Randomized controlled trials comparing direct stenting with other surgical methods are necessary to define the best revascularization strategy in patients with renovascular hypertension. A careful follow-up study after renal artery revascularization should evaluate possible benefits in halting the deterioration of chronic renal insufficiency.     

Percutaneous transluminal angioplasty in atheromatous stenosis of the renal artery. Late results

The purpose of the study was to analyse the effects on stenosis and blood pressure of percutaneous transluminal renal angioplasty in renovascular hypertension due to atheroma. Angioplasty was successfully performed in ten hypertensive patients (seven men and three women) with unilateral (seven patients) or bilateral (three patients) renal artery stenoses: dilation without complication, anatomic technical success in each case, and reduction in mean pick systolic-pressure across the stenosis. Recurrent stenoses were demonstrated in three men during the first year. After three years (mean follow-up), six patients were improved (normotensive under treatment), but all patients received an antihypertensive drug. Four failures were observed, due to recurrent stenosis in three cases. In patients with unilateral, non ostial and non completely occluded stenosis, improvement due to successful angioplasty was generally observed, incidence of recurrent stenosis was about 20 per cent. In contrast, neither cure nor improvement can be expected in patients with advanced bilateral atheromatous renal artery stenoses. A randomised trail appears necessary to demonstrate the potential improvement of renal function after angioplasty. Our results suggest that percutaneous transluminal renal angioplasty is effective for long-term control of renovascular hypertension (75 per cent) in patients with unilateral, non ostial, atheromatous artery stenosis.     

Mid-aortic syndrome: a case report and review of the literature

Renovascular disease is an important cause of secondary hypertension in children. In contrary to the adult patients whose major cause of renal artery stenosis (RAS) is atherosclerosis, fibromuscular dysplasia is responsible for the renovascular hypertension in most children. Mid-aortic syndrome (MAS) is a rare abnormality referring to an isolated disease of the distal thoracic and abdominal aorta resulting in significant tubular narrowing with stenosis of the visceral and renal arteries. It is usually diagnosed in young adults, but may present in childhood as a challenging problem. Patients with MAS are often first detected due to refractory hypertension. Other later presentations include intermittent claudication, congestive heart failure, renal insufficiency and symptoms of hypertensive associated end-organ damage. We report a case of a 16-year-old patient with MAS who suffered from malignant arterial hypertension. A percutaneous transluminal renal angioplasty (PTRA) was first performed, however the stenosis proved resistant to dilatation and only resulted in a minimal angiographic improvement. Due to persistent hypertension, an aortorenal bypass using the saphenous vein was performed. We also reviewed the literature on PTRA and the surgical management of RAS in MAS patients, in which PTRA often carries poor results.     

Usefulness of a percutaneous endoprosthesis in the treatment of renal artery stenoses

In approximately 10 p. 100 of the cases stenosis of the renal artery cannot be satisfactorily dilated by percutaneous transluminal angioplasty (PTA), and about 10 p. 100 of the patients successfully dilated have short-term restenosis. The excellent results obtained experimentally and clinically with the implantation of percutaneous intravascular stents have prompted us to use this material in the renal arteries. Stents were implanted in 10 patients who were followed up for periods of 1 to 16 months. Eight of them had restenosis after PTA; five of these stenoses were due to atheroma, 2 to fibromuscular dysplasia and 1 to Takayasu's disease. Two patients were implanted from the start owing to the insufficient results of PTA. Seven patients had severe arterial hypertension most probably of renovascular origin. Three patients had hypertension associated with moderate renal failure. Implantation was performed after a previous PTA. Adjuvant treatments and monitoring were the same in every case with, in particular, radiological control examination after one and six months. The implantations themselves were uneventful, and immediate control showed almost perfect anatomical restoration in all patients. On subsequent controls, arterial patency was preserved in all but one case. All patients showed significant clinical improvement. These results are most encouraging. They suggest that intravascular stents constitute an interesting solution when PTA is insufficient in the treatment of renal artery stenosis.     

Renal artery stenosis: epidemiology, clinical manifestation, and percutaneous endovascular therapy

Renal artery stenosis may cause or deteriorate arterial hypertension and/or renal insufficiency. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig in 1978, numerous single-center studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or by fibromuscular dysplasia. This article summarizes the impact of technical improvements of endovascular tools on interventional techniques during the last decade and gives an overview concerning the clinical impact of renal artery revascularization. Despite the absence of sufficient randomized studies, there is nonetheless evidence that stenting of hemodynamically relevant atherosclerotic renal artery stenosis has an impact on blood pressure control, renal function, and left ventricular hypertrophy.     

Renovaskuläre Hypertonie

Renovascular hypertension is diagnosed in about 1% of patients with arterial hypertension. Renal artery stenosis is caused by atherosclerotic lesions in most cases, and only in about 10% by fibromuscular dysplasia. As well as clinical scores, colour-coded duplex ultrasound and imaging by CT or MR angiography are established methods of diagnostic screening. Intraarterial angiography remains diagnostic gold standard allowing confirmation of the diagnosis. The difficulty in diagnosis when renal artery stenosis is known to be present lies mainly in differentiating between a clinically relevant stenosis and one that does not influence blood pressure and/or kidney function. Renal artery stenosis caused by fibromuscular dysplasia is generally treated by angioplasty, while conservative treatment is first tried for atherosclerotic renal artery stenosis. Revascularization is reserved for selected cases. Ongoing large trials will are intended to clarify the indications for revascularization in combination with optimal conservative management in atherosclerotic renal artery stenosis.     

Current state of diagnosis and endovascular treatment of renal artery stenosis

Renal artery stenosis may cause or deteriorate arterial hypertension and/or renal insufficiency. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig in 1978, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. This article summarizes the impact of technical improvements of endovascular tools on interventional techniques during the last decade and gives an overview concerning the clinical impact of renal artery revascularization. Despite the absence of sufficient randomized studies there is nonetheless evidence that stenting of hemodynamically relevant atherosclerotic renal artery stenosis has an impact on blood pressure control, renal function, and left ventricular hypertrophy.     

Percutaneous Angioplasty in the Management of Renovascular Hypertension

Abstract: Percutaneous angioplasty In the management of renovascular hypertension . W. B. McKenzie, J. Palmer and D. E. L. Wilcken, Aust. N.Z. J. Med., 1982,12, pp. 189–191.
Percutaneous transluminal angioplasty for renal artery stenosis is a brief procedure which has proven effectiveness and which can be performed under local anaesthesia with a low incidence of side effects. This report details the successful treatment of a patient with severe renovascular hypertension due to a stenotic left renal artery. Follow–up three months after balloon dilatation revealed continued wide patency of the vessel and the patient's blood pressure remained easily controlled.     

Percutaneous vascular interventions in renal artery diseases

Renal artery stenosis (RAS) is a progressive manifestation of atherosclerosis. It is associated with hypertension and progressive renal failure. Noninvasive testing includes renal artery duplex, computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). Percutaneous transluminal renal angioplasty and stenting (PTRAS) is indicated for significant atherosclerotic RAS while percutaneous transluminal renal angioplasty (PTRA) is indicated for fibromuscular dysplasias (FMD) associated with the proper clinical indications. PTRAS is associated with a high technical success rate and an acceptable adverse event and restenosis rate. PTRAS appears to improve control of hypertension and renal preservation. All patients should be followed clinically and with periodic duplex ultrasonography. Restenosis is treated with repeat angioplasty and occasionally stenting. Current and future areas of investigation will involve distal protection and drug eluting stents.