Current opinions in renovascular hypertension

A Unique Case of Renovascular Hypertension due to Fibromuscular Dysplasia in an Extra-renal Artery

A 33-year-old man was admitted to our hospital to undergo an evaluation to determine the cause of secondary hypertension. Computerized tomography angiography (CTA) showed bilateral multiple renal arteries with significant stenosis of the right extra-renal artery due to fibromuscular dysplasia and segmental impairment of renal perfusion. Although the plasma aldosterone concentration and plasma renin activity were within the normal ranges, percutaneous balloon dilatation of the stenotic lesion resolved his hypertension, leading to a diagnosis of renovascular hypertension caused by segmental renal ischemia due to extra-renal artery stenosis. CTA should be considered during the examination of patients with early-age hypertension, even if the plasma renin activity is not sufficiently elevated.

Successful Treatment of Resistant Hypertension by Means of Chronic Renal Artery Occlusion Revascularization in a Fragile Patient

BACKGROUND

Renal artery stenosis is a common cause of secondary hypertension refractory to medical therapy. Percutaneous angioplasty along with metallic stent placement has been described as an effective treatment for revascularization of the renal artery.

CASE REPORT

A 54-year-old woman affected by paranoid schizophrenia with a history of hypertension and chronic renal failure due to renal artery occlusion was treated by endovascular recanalization and stent placement that resulted in improvement of renal function and control of hypertension. Laboratory studies 4 months after the revascularization revealed blood creatinine decrease gradually from 8.57 mg/dL to 3 mg/dL.

CONCLUSIONS

Revascularization with stenting has proven to be a safe and effective procedure in the treatment of total renal artery occlusion which also led to a significant relief at a psychological level.

Effect of naringin on hemodynamic changes and left ventricular function in renal artery occluded renovascular hypertension in rats

Background:

Renal artery occlusion (RAO) induced hypertension is a major health problem associated with structural and functional variations of the renal and cardiac vasculature. Naringin a flavanone glycoside derived possesses metal-chelating, antioxidant and free radical scavenging properties.

Objective:

The objective of this study was to investigate the antihypertensive activity of naringin in RAO induced hypertension in rats.

Material and Methods:

Male Wistar rats (180-200 g) were divided into five groups Sham, RAO, naringin (20, 40 and 80 mg/kg). Animals were pretreated with naringin (20, 40 and 80 mg/kg p.o) for 4 weeks. On the last day of the experiment, left renal artery was occluded with renal bulldog clamp for 4 h. After assessment of hemodynamic and left ventricular function various biochemical (superoxide dismutase [SOD], glutathione [GSH] and malondialdehyde [MDA]) and histological parameters were determined in the kidney.

Results:

RAO group significantly (P < 0.001) increased hemodynamic parameters at 15, 30 and 45 min of clamp removal. Naringin (40 and 80 mg/kg) treated groups showed a significant decrease in hemodynamic parameters at 15 min. after clamp removal that remained sustained for 60 min. Naringin (40 and 80 mg/kg) treated groups showed significant improvement in left ventricular function at 15, 30 and 45 min after clamp removal. Alteration in level of SOD, GSH and MDA was significantly restored by naringin (40 and 80 mg/kg) treatment. It also reduced histological aberration induced in kidney by RAO.

Conclusion:

It is concluded that the antihypertensive activity of naringin may result through inhibition of oxidative stress.

Management of patients with resistant hypertension: current treatment options

Resistant hypertension (RHTN) is an increasingly common clinical problem that is often heterogeneous in etiology, risk factors, and comorbidities. It is defined as uncontrolled blood pressure on optimal doses of three antihypertensive agents, ideally one being a diuretic. The definition also includes controlled hypertension with use of four or more antihypertensive agents. Recent observational studies have advanced the characterization of patients with RHTN. Patients with RHTN have higher rates of cardiovascular events and mortality compared with patients with more easily controlled hypertension. Secondary causes of hypertension, including obstructive sleep apnea, primary aldosteronism, renovascular disease, are common in patients with RHTN and often coexist in the same patient. In addition, RHTN is often complicated by metabolic abnormalities. Patients with RHTN require a thorough evaluation to confirm the diagnosis and optimize treatment, which typically includes a combination of lifestyle adjustments, and pharmacologic and interventional treatment. Combination therapy including a diuretic, a long-acting calcium channel blocker, an angiotensin-converting enzyme inhibitor, a beta blocker, and a mineralocorticoid receptor antagonist where warranted is the classic regimen for patients with treatment-resistant hypertension. Mineralocorticoid receptor antagonists like spironolactone or eplerenone have been shown to be efficacious in patients with RHTN, heart failure, chronic kidney disease, and primary aldosteronism. Novel interventional therapies, including baroreflex activation and renal denervation, have shown that both of these methods may be used to lower blood pressure safely, thereby providing exciting and promising new options to treat RHTN.

Fibromuscular dysplasia affecting a two-branched renal artery in a patient with a solitary kidney: case presentation

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease, commonly involving the renal arteries. Here we report a case of a 16-year-old Chinese male who was found to have severe hypertension with proteinuria for 2 years. Computed tomography showed absence of the left kidney and enlargement of the right kidney. Subsequent angiography confirmed the above findings and revealed narrowing of both the upper and lower branches of the right renal artery caused by FMD. These combined lesions are very rare, and individuals affected are at increased risk of renal dysfunction if left untreated. Treatment with percutaneous balloon angioplasty is the first choice in such a patient and usually results in optimal outcomes.

Renovascular hypertension associated with pseudoaneurysm following blunt trauma

We present the case of a 21-year-old man who developed a renal artery pseudoaneurysm following a 7-foot fall onto his back. He initially presented with gross hematuria, left flank pain, and back pain. He was observed in the hospital for 3 days and discharged. One week later, he was readmitted with headache, nausea, vomiting, seizure activity, and hypertension. Contrast-enhanced computed tomography of the abdomen showed a left renal artery pseudoaneurysm with associated arterial narrowing and delayed ipsilateral renal enhancement. He underwent percutaneous stent-graft placement with resolution of the pseudoaneurysm. He was free of complications and normotensive off antihypertensive medications after 36 months of follow-up. Renal artery pseudoaneurysms are rare and under-recognized complications of blunt abdominal or back trauma that can cause hypertension. Imaging modalities in renovascular hypertension have focused on detecting renal artery stenosis from atherosclerotic disease or fibromuscular dysplasia, with little attention given to renal artery pseudoaneurysms. In addition, first-line treatment for renal artery pseudoaneurysms historically has consisted of angioembolization, yet percutaneous stent-graft placement has emerged as an attractive alternative to preserve vessel patency. We discuss the role of imaging in renovascular hypertension with a focus on renal artery pseudoaneurysms and their prevalence, diagnosis, and treatment.

Fibromuscular dysplasia--a rare cause of renovascular hypertension. Case study and overview of the literature data

Renal artery stenosis (RAS) is associated with increased cardiovascular mortality and morbidity and may constitute a treatable cause of secondary hypertension. Fibromuscular dysplasia is frequently affecting children as the main cause of RAS, but is very rare in adults. We present the case of a 19-year-old overweight patient, with no known pathological conditions in her medical history or family background, admitted for severe, pulsing headaches during the past 3 months and increased blood pressure (BP) values for about a month (maximum BP 220/140 mmHg). The initial clinical exam and first-line imagistic methods did not provide a high suspicion for RAS. However, the invasive methods established the diagnosis of right renal artery medial dysplasia. Balloon angioplasty was the treatment of choice.