An aneurysm describes a localized bulge or ballooning in the wall of a blood vessel, similar to a weak spot on an inflated balloon. Arteries are the most common sites for these bulges to form. While they often do not cause symptoms, their presence can be serious, as a rupture can lead to internal bleeding, which can be life-threatening.
Understanding Aneurysms
Aneurysms can develop in various arteries throughout the body, with the most frequent locations being the aorta and blood vessels within the brain. The aorta can develop aneurysms in the chest (thoracic aortic aneurysm) or the abdomen (abdominal aortic aneurysm). Brain aneurysms typically form in the arteries at the base of the brain.
These bulges arise when a segment of an artery wall weakens, allowing the force of blood flow to cause an outward expansion. While the exact causes are not always clear, contributing factors can include atherosclerosis and persistently high blood pressure. Genetic predisposition and a family history of aneurysms also contribute.
Can Aneurysms Resolve on Their Own?
For most common types of aneurysms, spontaneous resolution or disappearance without medical intervention is considered extremely rare. The structural integrity of the blood vessel wall has been compromised, and it lacks the ability to repair itself. The weakened area typically remains, and in many cases, can progressively enlarge over time.
There are, however, rare instances of spontaneous regression, particularly observed in certain intracranial aneurysms. These rare occurrences may be linked to specific anatomical factors, such as a narrow neck of the aneurysm, or changes in blood flow dynamics and coagulation pathways that promote the formation of a clot within the aneurysm sac. Even in these rare cases, regression is unpredictable and not a reliable outcome.
What Happens When an Aneurysm Persists?
When an aneurysm is detected but has not ruptured, medical professionals often adopt a strategy of careful monitoring, sometimes referred to as “watchful waiting.” This approach involves regular check-ups and imaging tests, such as CT scans or MRIs, to observe the aneurysm’s size, shape, and any changes over time. The decision to monitor versus treat immediately depends on factors like the aneurysm’s size, location, and the patient’s overall health and family history.
An unruptured aneurysm carries the risk of growing larger or rupturing. A ruptured aneurysm can lead to severe bleeding, such as a subarachnoid hemorrhage in the brain, which is a life-threatening medical emergency. This bleeding can cause significant brain damage, leading to complications such as:
- Hemorrhagic stroke
- Seizures
- Vasospasm (narrowing of blood vessels)
- Hydrocephalus (fluid buildup in the brain)
Even if a person survives a rupture, there is a risk of permanent disabilities, including speech difficulties, movement problems, or paralysis.
Treatment Approaches for Aneurysms
When an aneurysm requires intervention, treatment aims to prevent rupture by sealing off the weakened area of the blood vessel. Two primary approaches are commonly employed: surgical clipping and endovascular therapy. The choice of treatment is highly individualized, considering factors like the aneurysm’s location, size, shape, and the patient’s general health.
Surgical Clipping
Surgical clipping involves an open surgical procedure where a neurosurgeon accesses the aneurysm and places a small metal clip across its neck. This clip isolates the aneurysm from the bloodstream, thereby preventing further blood flow into it and reducing the risk of rupture.
Endovascular Therapy
Endovascular therapy, a less invasive option, involves inserting a catheter, typically through an artery in the groin, and guiding it to the aneurysm site using X-ray visualization. Tiny coils made of platinum are then deployed into the aneurysm, or a flow diversion device is placed in the parent artery, to block blood flow into the aneurysm, causing it to clot and effectively seal off.