Renal Artery Stenosis Treatment in Delhi, India

Renal Artery Stenosis (RAS) occurs when one or both arteries that supply blood to the kidneys become narrowed or blocked. These arteries are essential for delivering blood that the kidneys need to filter waste and regulate blood pressure. When the arteries narrow, blood flow to the kidneys decreases. In response, the kidneys release hormones like renin, which cause blood pressure to rise. Over time, this reduced blood flow and high blood pressure can damage the kidneys and affect their function. In severe cases, it can even lead to kidney failure. In simple terms, renal artery stenosis is a narrowing of the blood vessels that feed the kidneys, which can result in hard-to-control high blood pressure and potential kidney damage.

There are several causes of RAS-ranging from atherosclerosis to fibromuscular dysplasia. A detailed understanding of RAS causes is crucial for timely diagnosis and effective management.

Atherosclerosis

A subtype of arteriosclerosis, a vascular disease, atherosclerosisis the most common cause of renal artery stenosis, particularly in older adults. It occurs when plaque builds up inside the arteries, causing them to narrow, which leads to reduced blood flow. When renal artery stenosis is caused by atherosclerosis, it usually occurs in the proximal part of the affected renal artery.

Fibromuscular Dysplasia

More common in young and middle-aged women (20–50 years old), fibromuscular dysplasia is a non-atherosclerotic, non-inflammatory vascular disorder that leads to abnormal growth within the artery walls, making them too weak or stiff. It typically affects the distal part of the renal arteries.

Vasculitis

An autoimmune disease, vasculitis causes inflammation in blood vessels, including the renal arteries. Chronic inflammation triggers fibrosis (scar tissue formation), leading to narrowing (stenosis) of the affected renal artery. If a clot forms, the affected artery can further narrow.

Arterial Embolism

Arterial embolism is a serious condition in which a blood clot travels through the bloodstream and gets lodged in a renal artery, obstructing blood flow. Over time, repeated embolic events can cause progressive narrowing of the affected renal artery, leading to renal artery stenosis.

Neurofibromatosis Type 1

A genetic disorder caused by mutations in the NF1 gene, neurofibromatosis type 1 can lead to abnormal smooth muscle proliferation in the renal artery walls, which can cause the renal arteries to narrow. When RAS is caused by NF1, it can lead to malignant hypertension or kidney damage.

Several factors-ranging from underlying health conditions to lifestyle choices contribute to the development of RAS. An in-depth understanding of RAS risk factors can help those at high risk to take timely steps to prevent the condition.

An Inactive Lifestyle

A sedentary lifestyle can increase one’s risk of RAS by causing the following health conditions and issues that may lead to narrowing of the arteries supplying blood to the kidneys.

• Hypertension- Can lead to arteriosclerosis (hardening and narrowing of arteries)
• Obesity- Accelerates vascular damage
• Inflammation and oxidative stress can damage blood vessels, increasing the risk of renal artery stenosis.

Chronic Kidney Disease

CKD leads to vascular calcification (a buildup of calcium in the walls of blood vessels), which can stiffen arteries, increasing a person’s risk of renal artery stenosis. In some people, CKD causes dyslipidemia, hypertension, or chronic inflammation, all of which lead to accelerated atherosclerosis.

Drug Use

Cocaine, methamphetamine, and amphetamines can damage the arterial wall, increasing the risk of RAS. Heroin and synthetic cannabinoids can cause renal ischemia (a condition in which blood flow to the kidneys decreases significantly), leading to fibrosis and narrowing of the renal arteries.

Genetic Factors

Some variants of the angiotensinogen gene or angiotensin-converting enzyme gene can cause hypertension, which can lead to arterial damage. Familial hypercholesterolemia (caused by LDLR & PCSK9 mutations) causes plaque to build up in the renal arteries, leading to narrowed arteries.

Age

As people age, their renal arteries naturally stiffen and accumulate fatty deposits that can cause the arteries to narrow. Older adults are more likely to develop hypertension, diabetes, chronic kidney disease (CKD), and other conditions that can cause RAS.

RAS symptoms may vary depending on the severity of the condition and the underlying cause. Some patients may have mild symptoms, while others may be asymptomatic in early stages.

Kidney Dysfunction or Failure

When the kidneys do not receive enough blood, they can become damaged over time. A damaged kidney may struggle to perform its role effectively or shrink abnormally, leading to chronic kidney failure.

Fluid Retention and Swelling (Edema)

RAS causes the renal arteries to narrow, reducing blood flow to the kidneys. When this happens, the kidneys activate the renin-angiotensin-aldosterone system (RAAS). As a result, the adrenal glands produce aldosterone, a hormone that causes the body to retain more water than necessary.

Fatigue and Weakness

RAS triggers the renin-angiotensin-aldosterone system (RAAS), causing hypertension, which over time, can lead to vascular damage and poor oxygen delivery to tissues. Low oxygen levels can cause fatigue and weakness. Renal artery stenosis can also lead to decreased potassium levels-a common cause of tiredness.

Shortness of Breath

Severe or uncontrolled hypertension caused by RAS increases the workload on the heart, potentially leading to left ventricular hypertrophy (LVH) or heart failure. Congestive heart failure (CHF) causes fluid to flow back into the lungs, leading to dyspnea (shortness of breath), especially when lying down.

Dizziness or Confusion

RAS can affect the kidneys’ ability to control potassium levels. A sudden drop in potassium levels can lead to confusion or dizziness. The health condition can impair kidney function, causing waste products such as urea and creatinine to accumulate in the blood. High creatinine and urea levels can lead to confusion, lethargy, or cognitive impairment.

Timely and accurate diagnosis significantly improves renal artery stenosis treatment outcomes. Physicians use clinical evaluations, laboratory tests, and imaging techniques to check if the renal arteries have narrowed.

Clinical Evaluations

Doctors review their patients’ medical history (chronic conditions such as CKD and diabetes increase one’s risk of RAS) and perform a thorough physical examination to diagnose RAS. During a physical examination, a doctor may examine the patient’s abdomen for whooshing sounds, which may indicate turbulent blood flow.

Laboratory Tests

Blood tests can help doctors detect increased creatinine levels, abnormal blood urea nitrogen (BUN) levels, and electrolyte imbalances- all of which may indicate renal artery stenosis. A doctor may also order urine tests to see if protein or blood is present in the urine.

Duplex Doppler Ultrasound

A common imaging test used to diagnose renal artery stenosis, the duplex doppler ultrasound helps detect increased blood flow velocity at the stenotic site. A peak systolic velocity (PSV) exceeding 200 cm/s and a Renal-to-Aortic Ratio (RAR) exceeding 3.5 suggest a hemodynamically significant stenosis (≥60% narrowing).

Captopril Renal Scintigraphy

A type of nuclear medicine test, captopril renal scintigraphy, helps diagnose renal artery stenosis (RAS) by assessing kidney function before and after administration of captopril, an angiotensin-converting enzyme (ACE) inhibitor. When RAS affects the kidneys, captopril blocks the compensatory renin-angiotensin system (RAS), leading to a drop in glomerular filtration rate (GFR)

Renal Angiography

The gold standard for diagnosing renal artery diagnosis, renal angiography generates high-resolution images of the renal arteries, allowing doctors to identify any narrowing, blockages, or irregularities in blood flow. The imaging test is often used when other tests are inconclusive.

Effective treatment for RAS is essential to prevent complications such as chronic kidney disease and cardiovascular issues. Depending on the severity of RAS symptoms, a doctor may use one or more of the following RAS treatment options.

Hypertension Management

People with hypertension are at high risk of developing renal artery stenosis and should use ACE inhibitors, calcium channel blockers, beta-blockers or diuretics (as advised by their doctor) to control their blood pressure.

Cholesterol Management

Elevated cholesterol levels can cause a condition known as Atherosclerosis, in which plaque builds up inside the arteries, causing them to narrow and harden over time. Statins such as Atorvastatin and Rosuvastatin lower LDL cholesterol levels, reducing plaque buildup in the arteries.

Endovascular Procedures

If a patient has severe renal artery stenosis symptoms or uncontrolled hypertension, or is experiencing a progressive deterioration in kidney function, their doctor may recommend angioplasty and stenting. The procedure involves using a balloon to widen the artery, and placing a stent to keep it open.

Surgical Procedures

When endovascular procedures fail or are not suitable, a renal artery bypass or an endarterectomy is performed. A renal artery bypass involves placing a graft that reroutes blood flow around the affected artery. An endarterectomy is performed to surgically remove plaque from the renal artery.

RAS can be prevented by managing high blood pressure, high cholesterol, diabetes, and other risk factors for the chronic condition, and by making lifestyle changes to improve vascular health.

Maintain a Healthy Lifestyle

An unhealthy lifestyle can lead to obesity, hypertension, diabetes, and other health issues that can cause RAS. To reduce their risk of the chronic condition, one should add heart-healthy and potassium-rich foods to their diet and steer clear of foods with unhealthy fats. People who have a higher chance of developing RAS should exercise regularly to maintain a healthy weight and control their blood pressure. It's important that they quit smoking and cut down on alcohol as both tobacco and alcohol can damage blood vessels.

Manage Underlying Medical Conditions

Diabetes, atherosclerosis and other underlying conditions can cause blood vessels to narrow, leading to RAS. People who have diabetes should exercise regularly and avoid foods and drinks high in sugar to maintain their HbA1c levels below 7%. Individuals diagnosed with atherosclerosis should follow their doctor’s advice on diet, medications, and exercise to prevent serious damage to their blood vessels.

Get Blood and Imaging Tests Regularly

Periodic blood and imaging tests can help doctors monitor health conditions that can lead to RAS and check if blood vessels have narrowed. People at high risk of developing RAS should get:

• A kidney function test every year
• A renal artery Doppler ultrasound once a year
• An ECG and stress tests annually

Take Medications

In addition to maintaining a healthy lifestyle, people with underlying conditions that can cause RAS should take medications as instructed by their doctor. Here are some health conditions that can cause the chronic condition, and medicines that can help manage their symptoms.

• Diabetes- DPP-4 Inhibitors such as Sitagliptin, Linagliptin, and Saxagliptin
• Hypertension-ACE Inhibitors such as Enalapril, Lisinopril,, and Ramipril
• Atherosclerosis- ACE inhibitors such as Ramipril and Lisinopril

How does renal artery stenosis affect kidney function?

Renal artery stenosis reduces blood flow to the kidneys, triggering the release of hormones that raise blood pressure. Over time, this can lead to kidney damage or failure.

Can renal artery stenosis be reversed?

While medication can help manage the condition, procedures like angioplasty and stenting may be required to restore blood flow and improve kidney function.

Is renal artery stenosis same as kidney disease?

No, renal artery stenosis is a narrowing of the arteries supplying the kidneys, while kidney disease refers to a decline in kidney function due to various causes, including hypertension and diabetes.

Does renal artery stenosis always cause high blood pressure?

Not always, but it is a common cause of secondary hypertension, especially in younger patients or those with difficult-to-control blood pressure.

What lifestyle changes can help manage renal artery stenosis?

Maintaining a healthy diet, reducing sodium intake, quitting smoking, exercising regularly, and managing stress can help slow disease progression and control blood pressure.

Can renal artery stenosis lead to kidney failure?

Yes, in severe cases, prolonged reduced blood flow can cause kidney damage or failure, requiring dialysis or a transplant.

How is renal artery stenosis different from atherosclerosis?

Atherosclerosis is a general condition where arteries narrow due to plaque buildup. Renal artery stenosis specifically affects the arteries supplying the kidneys.

Does renal artery stenosis affect both kidneys?

It can affect one or both kidneys. When both renal arteries are narrowed, it can lead to a more serious condition called bilateral renal artery stenosis.

Can stress worsen renal artery stenosis?

Yes, chronic stress can raise blood pressure, worsening the effects of renal artery stenosis. Managing stress through relaxation techniques and a healthy lifestyle is important.

Are there any dietary restrictions for patients with renal artery stenosis?

A low-sodium, heart-healthy diet is recommended. Patients should also monitor protein and potassium intake if kidney function declines.

How does smoking impact renal artery stenosis?

Smoking accelerates the narrowing of arteries and worsens high blood pressure, significantly increasing the risk of kidney damage.

Can renal artery stenosis cause leg swelling?

Yes, if kidney function declines, fluid retention can lead to swelling in the legs, feet, and ankles.

Does renal artery stenosis cause fatigue?

Yes, reduced kidney function can lead to an imbalance in electrolytes and waste buildup, contributing to fatigue.

Can renal artery stenosis be hereditary?

While the condition itself is not directly inherited, genetic factors that increase the risk of high blood pressure and atherosclerosis may contribute.

Is renal artery stenosis more common in men or women?

It is more common in men, especially those with a history of smoking and cardiovascular disease. However, fibromuscular dysplasia, another cause of renal artery stenosis, is more common in women.

Can dehydration make renal artery stenosis worse?

Yes, dehydration can reduce blood volume, further limiting blood flow to the kidneys and exacerbating the condition.

Does renal artery stenosis affect urination?

In later stages, reduced kidney function may cause decreased urine output, but early stages typically do not affect urination.

What medications should be avoided with renal artery stenosis?

Nonsteroidal anti-inflammatory drugs (NSAIDs) and certain blood pressure medications like ACE inhibitors or ARBs should be used cautiously, as they may worsen kidney function in some cases.

Can renal artery stenosis affect other organs?

Yes, since it contributes to high blood pressure, it increases the risk of heart disease, stroke, and damage to other organs over time.

How often should someone with renal artery stenosis have check-ups?

Regular check-ups every 3 to 6 months are recommended to monitor kidney function, blood pressure, and overall cardiovascular health.

Reviewed by Dr. Pankaj Panwar, Principal Consultant - Uro-Oncology and Robotic Surgery, Surgical Oncology, Cancer Care, on 21 Apr 2025.