Is a Renal Artery Aneurysm Dangerous?

A renal artery aneurysm is a rare condition that often goes unnoticed until it’s discovered during diagnostic procedures for unrelated medical conditions.

Most people with renal artery aneurysms show no symptoms, but in rare cases, renal aneurysms may rupture and become life-threatening.

In this article, we’ll explain what a renal artery aneurysm is, when it can be dangerous, and how to treat and manage it.

What is a Renal Artery Aneurysm (RAA)?

Renal artery aneurysm (RAA) refers to a rare, often asymptomatic condition characterized by the abnormal expansion of the wall of one or both arteries that supply blood to the kidneys.

This expansion results from a weakening of the vessel wall.

Despite its rarity, a renal artery aneurysm is a critical health concern, with estimates suggesting it affects less than 1% of the general population.

However, the true prevalence of RAA remains unknown, as the condition frequently goes undetected until investigations for unrelated health issues reveal its presence.

What are the Different Types of Renal Artery Aneurysms?

True aneurysm

A true aneurysm occurs when all three layers of an artery wall weaken and bulge out.

This condition often affects people with other health issues like fibromuscular dysplasia (a condition that changes the size and shape of blood vessels), vasculitis (which involves swelling of the blood vessels), and fungal infections.

These aneurysms are often found on the main renal artery where it branches out to form smaller arteries.

There is a risk that true aneurysms can burst and cause internal bleeding. However, the chance of this happening in renal artery aneurysms is relatively low, affecting only 3-5% of individuals with the condition.

Pseudoaneurysms

Also known as false aneurysms, pseudoaneurysms occur when the arterial wall is damaged, leaving only the outermost layer or surrounding tissue to prevent blood from leaking out of the artery.

Imagine repairing a burst water pipe with Saran wrap; water can still flow within the pipe, but it will bulge out at the patched area, creating a pouch that might eventually burst.

Similarly, in serious cases of pseudoaneurysms, the blood may be contained only by the outermost layer of the vessel wall or even just the surrounding tissues.

Like the burst pipe scenario, these vessels can rupture, leading to internal bleeding.

Dissecting aneurysms

These aneurysms tear through the innermost wall of the artery and separate the layers of the blood vessel wall in which they occur, allowing blood to escape into the wall of the artery itself.

This can arise as a complication of a true aneurysm.

How Serious is a Renal Artery Aneurysm?

In most instances, renal artery aneurysms that are discovered do not require immediate treatment, but rather ongoing monitoring.

This approach ensures that the aneurysm does not progress to a point where it poses a significant risk to your health.

A study conducted by the Journal of Vascular Surgery showed that the growth of renal artery aneurysms is slow and has low rates of rupture even after more than 20 years following diagnosis. However, potentially severe complications may occur in rare cases.

One of the more dangerous complications involves rupture of the aneurysm which may cause internal bleeding. If this occurs, the risk of dying is about 10% and it rises to about 55% if you are pregnant at the time of rupture. The reason for increased risk in pregnancy is unclear.

What are the Causes and Risk Factors for a Renal Artery Aneurysm?

A renal artery aneurysm is a complex condition that may result from various factors, ranging from medical procedures to underlying health issues.

Identifying the causes and risk factors is crucial for prevention and management.

Iatrogenic injury

This refers to injuries caused by medical treatments.

Procedures such as kidney removal surgery, treatments for kidney stones, kidney biopsies, and kidney transplants can inadvertently lead to the development of RAA as a complication.

Hypertension

A significant connection exists between RAA and high blood pressure. Hypertension is not only a common condition among individuals with RAA, but also a critical risk factor for its development.

One study found that between 52% and 74% of people with RAA had hypertension. Another study found an even stronger link — nearly 90% of symptomatic patients had systemic hypertension.

Fibromuscular dysplasia (FMD)

FMD is a rare condition that mainly affects women and involves abnormal cell growth in the walls of blood vessels, leading to narrowing, bulging, or both.

The arteries in the brain and kidneys are most commonly affected, sometimes resembling a string of beads due to alternating areas of narrowing and bulging.

FMD is a contributing factor to the development of hypertension and about 40% of individuals with FMD have RAA, highlighting a significant link between the two conditions.

How Do You Treat a Renal Artery Aneurysm?

The management of renal artery aneurysms depends on a variety of factors. Healthcare providers have guidelines they use to determine whether your specific aneurysm needs surgical or nonsurgical management — more on this soon.

Watchful waiting

Also known as active surveillance, watchful waiting is a cautious treatment strategy that focuses on regular, long-term monitoring of your condition to detect any changes over time. Active treatment is reserved for cases where the condition shows signs of worsening.

Watchful waiting is particularly effective in managing conditions like renal artery aneurysms, which often do not rupture or cause symptoms.

Interestingly, around 40% of these aneurysms may undergo calcification, a process believed to offer resistance to rupture.

The watchful waiting approach typically involves periodic assessments through ultrasound or computerized tomography (CT) scans.

This ensures that any progression of your renal artery aneurysm is carefully monitored and addressed only if necessary, thereby reducing the risks associated with unnecessary treatments.

Surgical interventions

As mentioned above, surgery for renal artery aneurysms is only considered under certain circumstances.

Your doctor may consider a surgical approach to management if:

• You have an aneurysm that has ruptured.
• Your renal artery aneurysm is accompanied by coexisting conditions such as hypertension. The link between RAA and hypertension is particularly strong when RAA coexists with renal artery stenosis (when one or more renal arteries narrow), potentially leading to severe hypertension that can damage organs. Some danger signs include visual changes, severe headaches, chest pain, dizziness, and shortness of breath.
• You are pregnant or trying to conceive.
• Your RAA is growing.
• You have a dissecting aneurysm.
• You have an RAA with a diameter greater than 2cm. Medical professionals vary in their recommendations regarding the specific size at which surgery for an aneurysm is advised, with documented instances of rupture occurring in aneurysms as small as 1.5cm. Your healthcare provider will conduct a thorough evaluation to develop a plan that best suits your needs.

Surgery

Emergency surgical repair

This is crucial for managing internal bleeding resulting from a ruptured aneurysm, due to the high risk of mortality associated with such ruptures. In some cases, controlling the bleeding may require the removal of the affected kidney.

However, if the situation is not life-threatening, your surgeon may perform renal artery reconstruction to save the kidney.

Cesarean section (C-section)

If you are pregnant, C-sections should be avoided as far as possible to minimize blood loss caused by additional surgeries.

However, it can be considered if the uterus is obstructing the surgeon’s view for the renal artery repair or if the lives of the mother or fetus are at risk.

Open surgery

During open surgery, an incision is made that provides a full view of the organs being operated on. It is traditional surgery as opposed to “key-hole” or endoscopic surgery.

• Patch repair: A surgeon may remove the bulging part of the artery and patch the hole using part of a vein from another part of your own body or a prosthetic.
• Nephrectomy or partial nephrectomy: Removal of all or part of the kidney that the artery with the aneurysm supplies. This approach is adopted if the kidney serviced by the artery is nonfunctional, if prior attempts at artery reconstruction were unsuccessful, or if the patient's life is endangered by the condition.
• Removal of affected artery segment: In FMD, where a large portion of the renal artery may be affected, the entire affected segment can be surgically removed and replaced with a segment of vein from your own body.

Endovascular interventions

These procedures involve inserting a catheter (pipe/tube) into a blood vessel and operating only inside the blood vessel. These procedures are performed under imaging guidance, allowing doctors to visualize the entire process in real-time.

• Coil embolization: A platinum or steel wire is inserted through an incision into the blood vessel via a catheter and guided to the aneurysm, where the wire then coils. The coiled wire promotes clotting and effectively seals off the aneurysm by stopping blood flow into it.
• Stent grafts: A stent coated with Teflon or Gore-Tex is inserted into the aneurysm through a blood vessel. Initially flattened for smooth passage, it expands inside the aneurysm to block blood flow to it while ensuring normal blood flow to the affected kidney.

Additional treatments will focus on managing coexisting conditions, particularly hypertension, alongside long-term monitoring to verify the ongoing effectiveness of any repairs.

Where Can You Learn More About Kidney Health?

If you have one or more risk factors for renal artery aneurysms or you’re concerned about your symptoms, be sure to seek medical attention. This condition can become serious if not properly managed or treated.

If you have been diagnosed with RAA, ongoing care will most likely be part of your treatment plan, so be sure to find a healthcare provider that you feel comfortable with.

If you have any other questions about kidney health, LifeMD can provide answers and guidance on your concerns. To get started, make a virtual appointment today.