Renal hypertension, a cause of systemic hypertension, is the result of stenosis or occlusion in the renal artery/arteries and the subsequent under perfusion of one or both kidneys [1]. 90% of cases are caused by atherosclerotic renal artery stenosis (ARAS), which affects males above the age of 50 years while the remaining are secondary to fibromuscular dysplasia (FMD), which is commonly found in younger women [2] [3].

While some patients are asymptomatic, headache is the most frequent manifestation in others. Further complaints include emesis, visual disturbances, and changes in the mental status. If the patient has developed congestive heart failure, the clinical presentation consists of fatigue, dyspnea on exertion, peripheral edema, palpitations, and other associated symptoms [4]. Moreover, individuals with renal disease are likely to exhibit hematuria and edema [4].

There are numerous risk factors for renal hypertension such as malignant hypertension, progressive renal impairment, diastolic blood pressure greater than 120 mm Hg, hypertension unresponsive to multidrug therapy, and worsening blood pressure with diuretic use. Furthermore, hypertension accompanied by proteinuria and azotemia is another risk.

Patients with renal hypertension typically have a history of 1) a sudden increase in blood pressure, 2) onset of hypertension in the absence of risk factors, 3) worsening of previously controlled hypertension, 4) repeat episodes of pulmonary edema, 5) unprovoked hypokalemia, 6) generalized atherosclerosis in older individuals, and/or 7) smoking,

Complications

Sequelae include chronic hypertension, kidney disease, renal failure, heart failure, seizures, encephalopathy, coma, and even death. Also, end-organ damage is a concern especially in the setting of chronic kidney disease [5] [6].

• Renal Artery Stenosis

  Renal hypertension, a cause of systemic hypertension, is the result of stenosis or occlusion in the renal artery/arteries and the subsequent under perfusion of one or both kidneys. 90% of cases are caused by atherosclerotic renal artery stenosis (ARAS [symptoma.com]

  This is a report of hypertension caused by stenosis of a segmental renal artery and cured by simple ligation of the stenotic artery. [ncbi.nlm.nih.gov]

• Resistant Hypertension

  Data from the NHANES2 shows that 12.8% of drug-treated hypertension patients (n=539) meet the criteria for resistant hypertension. [af-ablation.org]

  CONCLUSION: MDCT is widely used for renal artery evaluation in patients with resistant hypertension. [ncbi.nlm.nih.gov]

  […] include the following: Percutaneous transluminal angioplasty (PTA) Surgical revascularization Nephrectomy Catheter-based radiofrequency denervation of the renal arteries has entered clinical use in many countries as a treatment for resistant hypertension [emedicine.medscape.com]

  Others feel that ARAS patients with multi-drug-resistant renovascular hypertension, advanced CKD (stages 4–5), 48 or steadily deteriorating renal function should undergo revascularization ( Table 3, Figure 5 ). [eurheartj.oxfordjournals.org]

• Fatigue

  If the patient has developed congestive heart failure, the clinical presentation consists of fatigue, dyspnea on exertion, peripheral edema, palpitations, and other associated symptoms. [symptoma.com]

  The symptoms include weight loss, poor appetite, nausea and vomiting, fatigue, darkening of skin (only in primary adrenal insufficiency), abdominal pain, among other. [hopkinsmedicine.org]

  When the kidneys are not working well, wastes can build to high levels in the blood, causing symptoms such as swelling of the hands and feet, nausea and vomiting, fatigue and poor appetite. [kidney.org]

• Abdominal Bruit

  Headache, tinnitus, dizziness, neck pain, and cervical/abdominal bruits may also be present (46). The diagnosis for FMD is based on diagnostic imaging with catheter-based angiography being the ‘gold standard’. [guidelines.hypertension.ca]

  One remarkable finding in nearly 50% of affected individuals is an abdominal bruit, especially when present during both diastole and systole. Target-organ effects of chronic hypertension should also be investigated. [symptoma.com]

  Such findings may include the following: Recurrent flash pulmonary edema or unexplained episodes of congestive heart failure Advanced funduscopic changes Abdominal bruit – A clear abdominal bruit is heard in 46% of patients with RVHT, as well as in 9% [emedicine.medscape.com]

  However, up to 10% of patients with essential primary hypertension may have an abdominal bruit and innocent abdominal bruits are present in a minority of healthy younger patients, so it is not a pathognomonic sign. [patient.info]

  Abdominal bruits serve as a clinical sign of vascular stenosis. Difference in kidney size or unexplained renal insufficiency also raises clinical suspicion. [clinicaladvisor.com]

• Nausea

  […] body, such as to the legs, the brain, the eyes and elsewhere Sudden buildup of fluid in the air sacs of the lungs ( pulmonary edema ) If you have a dangerous form of high blood pressure called malignant hypertension, symptoms can include: Bad headache Nausea [nlm.nih.gov]

  […] body, such as to the legs, the brain, the eyes and elsewhere Sudden buildup of fluid in the air sacs of the lungs (pulmonary edema) If you have a dangerous form of high blood pressure called malignant hypertension, symptoms can include: Bad headache Nausea [pennmedicine.org]

  The symptoms include weight loss, poor appetite, nausea and vomiting, fatigue, darkening of skin (only in primary adrenal insufficiency), abdominal pain, among other. [hopkinsmedicine.org]

• Hypertension

  Abstract PG A1, B1, E2, F1,2alpha and PRA have been measured in 8 hypertensive patients with unilateral renal arterial stenosis, 7 hypertensive patients with unilateral renal atrophy and 20 control normotensive subjects. [ncbi.nlm.nih.gov]

• Diastolic Hypertension

  Renovascular hypertension should be suspected if Diastolic hypertension develops abruptly in a patient 30 or > 50 New or previously stable hypertension rapidly worsens over a period of 6 mo Hypertension is initially very severe, associated with worsening [merckmanuals.com]

• Fracture

  AI can detect, localize fractures on wrist x-rays January 31, 2019 -- An artificial intelligence (AI) algorithm can both detect and show the position of fractures on wrist radiographs with a high level of sensitivity and specificity, according to research [auntminnie.com]

• Kidney Failure

  Uncontrolled hypertension may result in fatal heart attack, heart failure, kidney failure, blocked arteries in arms or legs, stroke, eye damage or poor quality of life. [cincinnatikidneydocs.com]

  Acute-on-chronic kidney failure [ edit ] Acute kidney injuries can be present on top of chronic kidney disease, a condition called acute-on-chronic kidney failure (AoCRF). [en.wikipedia.org]

  What groups are at risk for kidney failure related to high blood pressure? All racial groups have some risk of developing kidney failure from high blood pressure. [kidneyurology.org]

  IMAGES Hypertensive Kidney Disease See a detailed illustration of the kidneys See Images Who is at risk for kidney failure related to high blood pressure? Everyone has some risk of developing kidney failure from high blood pressure. [medicinenet.com]

• Renal Injury

  In all, these studies indicate that renal injuries may activate renal afferent pathways that connect with integrative brain structures in SNS activity and blood pressure. [ncbi.nlm.nih.gov]

  […] the notion that interventions targeting renal injury pathways might constitute an adjunct or even alternative strategy to ensure adequate recovery. [eurheartj.oxfordjournals.org]

  injury, it is recommended that gadolinium contrast agents not be administered unless a risk-benefit assessment for that particular patient indicates that the benefit clearly outweighs the potential risks. 19 NUCLEAR MEDICINE ACE-INHIBITOR RENOGRAPHY [aafp.org]

• Headache

  We report a 40-year-old lady who presented with severe headaches, persistent microscopic haematuria and hypertension requiring anti-hypertensive medication. Investigations for secondary hypertension were all normal except for a CT scan. [ncbi.nlm.nih.gov]

  Occasionally patients with high blood pressure feel following symptoms: Confusion Headache Double or blurry vison Pink-colored urine Nosebleed Treatments for Renal Hypertension Medication is usually the first line of defense to keep blood pressure in [cincinnatikidneydocs.com]

  While some patients are asymptomatic, headache is the most frequent manifestation in others. Further complaints include emesis, visual disturbances, and changes in the mental status. [symptoma.com]

  Those with severe renal hypertension may experience the following symptoms: Headache and double vision Blood in urine Nosebleed Confusion Renal hypertension is dangerous because it can cause chronic kidney disease, a condition in which symptoms aren’t [reverehealth.com]

  Symptoms of severely elevated blood pressure include: Headache Confusion Blurry or double vision Bloody (pink-colored) urine Nosebleed The vast majority of people with renal hypertension never experience these (or any) symptoms. [webmd.com]

Individuals with a clinical presentation or a history as described above warrant a full workup. The assessment consists of the patient's personal and family history, physical exam, and the appropriate studies.

Physical exam

The patient's blood pressure and other vitals must be assessed with the proper techniques in order to ensure accuracy. Very importantly, the patient should be examined carefully. One remarkable finding in nearly 50% of affected individuals is an abdominal bruit, especially when present during both diastole and systole [7] [8].

Target-organ effects of chronic hypertension should also be investigated. For example, patients with heart failure will exhibit peripheral edema and other cardiovascular signs while those with ophthalmologic manifestations will have retinal hemorrhages and retinopathy.

Laboratory tests

A complete blood count (CBC) and a complete metabolic panel (CMP), which includes electrolyte levels and renal function tests, are important components of the workup [4]. Fasting glucose and fasting lipid tests are indicated in children with chronic kidney disease, individuals with severely elevated blood pressures, and other groups as well [4]. To examine rare causes of hypertension, a 24-hour urine collection can be used to measure creatinine, electrolytes and other metabolites [4].

Imaging

Intra-arterial digital subtraction angiography (DSA) is currently recommended as the initial study in the assessment of renal artery stenosis, especially in patients with renal impairment. Along with DSA, renal arteriography is also the gold standard diagnostic technique.

Magnetic resonance angiography (MRA) offers critical information regarding the renal arteries, their branches, anatomic variants, distal stenosis, and any suspicious masses. One meta-analysis study reports that gadolinium-enhanced MRA is associated with a 97% sensitivity and 85% specificity for detection of renal artery stenosis [9]. Computed tomographic angiography (CTA) is also another technique used to diagnose stenosis.

Multidetector contrast tomography (MDCT) provides details about the renal artery and parenchyma of the kidneys as well nearby structures [10]. Another study is doppler ultrasonography, which allows for the evaluation of the anatomy and function of the renal arteries. This modality is associated with good sensitivity and specificity for detection of stenosis [11]. Additionally, a nuclear renal scan can be used to determine if a patient will benefit from surgery [12]. This test can be used with captopril for enhancement.

• Unilateral Small Kidney

  The mechanism is different in unilateral or bilateral renal artery stenosis: In significant unilateral stenosis the plasma renin activity increases as a result of ischemia in the affected kidney. [escardio.org]

• Hyperuricemia

  The data from a related series of studies suggest that the hyperuricemia in both types of hypertension results from diminished renal excretion of urate. [nejm.org]

• Left Ventricular Hypertrophy

  Left ventricular hypertrophy remains the most thoroughly documented form of end-organ damage caused by hypertension in children and adolescents with CKD. [ncbi.nlm.nih.gov]

  Complications result directly from the increased pressure (cerebral hemorrhage, retinopathy, left ventricular hypertrophy, congestive heart failure, arterial aneurysm, and vascular rupture), from atherosclerosis (increased coronary, cerebral, and renal [britannica.com]

No side effects occurred during treatment except for one case of reversible acute renal failure in a transplanted patient with renal artery stenosis. [ncbi.nlm.nih.gov]

The increasing use of such potent antihypertensive agents as the angiotensin I converting enzyme inhibitors has empha sized the problem of renal artery stenosis in older patients with wide spread vascular disease as well as improving the prognosis of [springer.com]

[…] renal artery dissection (e.g. from trauma or aortic dissection ) renal infarction Page kidney renal artery embolism or thrombosis EVAR stent graft encircling tumor (e.g. pheochromocytoma ) radiation-induced fibrosis polyarteritis nodosa Treatment and prognosis [radiopaedia.org]

Inpatient care is necessary for the management of hypertensive urgencies, quick intervention is required to prevent further damage to the kidneys. [10] Prognosis [ edit ] Prognosis of individuals with renovascular hypertension is not easy to determine [en.wikipedia.org]

The etiology, presentation, and management are presented. Follow-up varied from 2 to 14 years and the outcome is discussed. [ncbi.nlm.nih.gov]

ETIOLOGY RENAL STENOSIS  Decrease in the diameter of the renal arteries  Atherosclerosis; fat, cholesterol, calcium and other material found in the blood  Fibromuscular dysplasia; abnormal development or growth of cells on the renal artery walls Fibromuscular [slideshare.net]

Etiology There are a number of conditions that can cause RVH 1-3 : atherosclerotic renal artery stenosis (~90%) fibromuscular dysplasia (second most common) There are other causes that can cause renal artery obstruction but these are much rarer 2,3 : [radiopaedia.org]

Epidemiology [ 3 ] The prevalence of atherosclerotic renal artery stenosis is high - about 7% in individuals older than 65 years and about 50% in patients with diffuse arterial disease, and it is increasingly frequent in an ageing population. [patient.info]

(pg. 780 - 788 ) 39 Prospective evaluation of aggressive medical therapy for atherosclerotic renal artery stenosis, with renal artery stenting reserved for previously injured heart, brain, or kidney, Am J Cardiol, 2006, vol. 96 (pg. 1322 - 1327 ) 40 Epidemiology [eurheartj.oxfordjournals.org]

PATHOPHYSIOLOGY 2 ways: 1. Increased renal vascular resistance 2. [slideshare.net]

The propensity for angiotensin receptor blockers (ARBs) to affect GFR adversely is based on similar pathophysiology. [emedicine.medscape.com]

Pathophysiology To make a renovascular hypertension diagnosis, RAS evaluation is required but not sufficient. [escardio.org]

In rats with 5/6 nephrectomy, the turnover rate of norepinephrine was increased in brain nuclei involved in the noradrenergic control of blood pressure, and dorsal rhizotomy prevented hypertension. [ncbi.nlm.nih.gov]

Prevention Preventing atherosclerosis may prevent renal artery stenosis. Taking the following steps can help: Lose weight if you are overweight. Ask your provider about your smoking and alcohol use. Control your blood sugar if you have diabetes. [mountsinai.org]

Two opportunities for preventing renal hypertension are offered: chronic pyelonephritis and radiation nephritis. Received June 11, 1962. Accepted September 24, 1962. [pediatrics.aappublications.org]

Preventing atherosclerosis may prevent renal artery stenosis. Taking the following steps can help: Lose weight if you are overweight. Ask your provider about your smoking and alcohol use. Control your blood sugar if you have diabetes. [nlm.nih.gov]

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