Medical Management and Observation of Aneurysms

Most brain aneurysms go undetected for an entire lifetime. When an unruptured aneurysm is discovered, a decision must be made about whether it should be treated surgically or observed and medically managed. In this article we will discuss the factors involved in making this decision and describe what observation and medical management of a brain aneurysm entails.

Brain aneurysms are weakened areas in the blood vessels of the brain that balloon out and have the potential to rupture and cause potentially disabling or fatal bleeding. Ruptured aneurysms require treatment, whether by open or endovascular surgery, to prevent them from rupturing again.

Aneurysms may also be discovered before rupturing, often during brain imaging for an unrelated issue. When this occurs, a decision must be made whether to treat the aneurysm or observe it.

Deciding whether to treat a brain aneurysm or monitor it involves weighing the risks of treatment against the risk of the aneurysm rupturing and causing bleeding in the brain. This can be a tough decision because a rupture can be very serious.

However, it’s important to remember that surgery also carries risks, such as causing a hemorrhage or stroke during the procedure, which could lead to disability or be fatal. These risks are rare, but so is the chance of an untreated aneurysm rupturing.

When deciding between surgery and observation, doctors consider factors that could increase the risk of rupture. While some aneurysms may never cause problems, others may be more likely to rupture and may benefit from treatment.

Factors that increase the risk of rupture include the aneurysm’s size, location, and shape. Small, uniform aneurysms may have a lower risk of rupture than surgery and can often be monitored. Large or irregularly shaped aneurysms may be more likely to rupture, making surgery a better option.

Other important considerations include the patient’s age and overall health. Because every case is unique, decisions about treating or observing an aneurysm should be made in close consultation with your doctor, based on your specific situation.

Brain aneurysms are relatively common, with about 6% of people in the U.S. having one. Most people never know they have an aneurysm because they have not had symptoms warranting the imaging tests that would detect an aneurysm.

If a decision is made to monitor the aneurysm rather than treat it right away, the following steps are typically involved:

• Imaging Studies: Regular imaging tests like MRI, CTA, or cerebral angiography will be done to check for changes in the aneurysm over time.
• Risk Factor Management: Control of risk factors like high blood pressure or smoking. This may include taking medications to lower blood pressure and cholesterol.
• Follow-Up Appointments: Regular checkups will be scheduled to review imaging results, track symptoms, and adjust the management plan as needed.

An unruptured aneurysm will not go away on its own, so making healthy lifestyle choices and managing other medical conditions is important to reduce the risk of rupture. While no medication can treat an aneurysm directly, medications may help reduce the chances of it growing or rupturing once it has been found.

Some brain aneurysms may never cause problems, and people can live their whole lives without knowing they have one. However, the risk of rupture increases over time, which is why regular imaging and a careful discussion of treatment options are important if monitoring is chosen. If imaging shows that the aneurysm has grown or changed shape, treatment may be necessary.

While many aneurysms can be observed, some may require treatment to address symptoms related to the aneurysm, or when the risk of rupture is greater than the risks associated with definitive treatment. Aneurysms that are associated with an increased risk of rupture include the following:

• Large Size: Aneurysms larger than 7 mm have a higher risk of rupturing. In some locations, even aneurysms over 5 mm can be concerning.
• Irregular Shape: If the aneurysm has blebs or blisters, it may indicate weak spots, making it more likely to rupture.
• Location: Aneurysms in certain areas, like the vertebral, basilar, or posterior cerebral arteries, have a higher chance of rupturing.
• Previous Rupture: Once an aneurysm has ruptured, it is at higher risk of re-rupturing—4-13% within the first 24 hours and 50% within 6 months. After 6 months, the risk drops to about 3% per year.
• Presence of Symptoms: Aneurysms causing symptoms like headaches or vision problems may have a higher risk of rupture.

Changes in the way that your aneurysm is approached can occur at any time. Discuss any concerns with your medical team promptly to align your management plan with your treatment goals.

• Certain factors can increase the risk of rupture and should be considered when deciding on surgery.
• Monitoring unruptured aneurysms involves regular imaging to check for changes. If the aneurysm grows or changes shape, surgery may be needed.
• Lifestyle changes and medications to lower cholesterol and blood pressure can help reduce the risk of aneurysm growth and rupture.
• Medical management can lower the risk of rupture but cannot make the aneurysm disappear.

• National Institute of Neurological Disorders and Stroke
• American Association of Neurological Surgeons (AANS): Cerebrovascular Disease
• Brain Aneurysm Foundation
• American Association of Neurological Surgeons (AANS): Cerebral Aneurysm
• American Brain Foundation (ABF)