Cerebral Aneurysm

What Is a Cerebral Aneurysm?

A cerebral aneurysm is a sac-shaped dilatation of a brain vessel. Vessel dilation is not uncommon, though it is often undetected or discovered at random. Cerebral aneurysms occur more frequently after 40, and women are affected more often than men.

Cerebral aneurysms are vascular malformations of the brain. Over the years, the vessel around the aneurysm loses more and more elastic fibers and expands. As a result, preferred sites have high mechanical stress, such as the larger cerebral vessels bifurcate. In the worst case, such an aneurysm can lead to cerebral hemorrhage and death by rupturing the vessel wall.

What Are the Causes of a Brain Aneurysm?

The cause of a cerebral aneurysm is usually a congenital weakness of the vessel wall. However, other factors can also be causative, such as arteriosclerosis, inflammation of the vessels, drug abuse, or certain hereditary diseases, such as Marfan syndrome.

Brain Aneurysm Symptoms

About half of the people with brain aneurysms have no symptoms (asymptomatic). They are usually discovered at random in CT (computed tomography) or MRI (magnetic resonance imaging).

However, depending on the location of the aneurysm, a wide variety of symptoms can occur, usually caused by the displacement of brain or nerve tissue. These include visual, hearing, or balance disorders, paralysis, epileptic seizures, and headaches.

An aneurysm becomes noticeable through a rupture (tearing of the vessel wall) in the worst case. This type of brain hemorrhage is also called a subarachnoid hemorrhage (SAB) and equivalent to a bloody stroke.

How Is an Aneurysm of Cerebral Vessels Detected?

The best results are obtained by radiology using particular types of vascular imaging, with or without contrast medium, in CT (computed tomography) and MRI (magnetic resonance imaging). MRI is the standard for frequent follow-up examinations due to the lack of radiation exposure.

The more invasive method of catheter angiography (vascular imaging via a metal wire in the vessel and administration of contrast medium there) is only used preoperatively for precise measurement and surgical planning due to the higher complication rate. However, in the case of rupture and aneurysm bleeding, it simultaneously offers surgery through the catheter.

Cerebral Aneurysm Therapy

The treatment of a cerebral aneurysm depends on its size and location, the patient’s symptoms, and any aneurysm bleeding that has already occurred. The purpose of the treatment is to prevent a possible hemorrhage. Non-symptomatic aneurysms up to 7 mm in size are not treated because the risk of surgery is greater than the risk of bleeding.

Cerebral Aneurysm Surgical Procedure

Treatment is recommended for aneurysms larger than 7 mm in diameter. However, if aneurysms are symptomatic, they are treated regardless of their size. Neurosurgery distinguishes between two standard treatment options: aneurysm clipping and aneurysm coiling. Which of the two surgeries is preferable depends on various factors and is discussed individually with the treating physician.

Clipping is an open surgery in which a clip is used to close the affected piece of the vessel. Coiling is a surgery where a small wire is forwarded to the aneurysm via an artery that supplies the brain. At the tip of the wire is a platinum coil that expands in place, and the subsequent clotting of blood around the "foreign body" closes the aneurysm.

Prognosis and Life Expectancy in Brain Aneurysm.

Non-symptomatic small aneurysms have a very low risk of a cerebral hemorrhage. Nevertheless, to detect changes in size, control examinations must take place at specific intervals.

In case of known cerebral vascular aneurysms and symptoms suggesting pressure damage of surrounding structures, attention must be paid. A rupture of the vessel wall with cerebral hemorrhage follows in most cases, which urgently requires treatment. However, if this is done before bleeding, good long-term results can be expected.

In principle, all risk factors that support aneurysm formation and enlargement should be eliminated, including, for example, smoking, high blood pressure, and alcohol abuse.

Sources:

http://www.awmf.org/leitlinien/detail/ll/030-030.html

Henne-Bruns, Doris; Dürig, Michael; Kremer, Bernd; Bruns, Doris Henne-: Chirurgie. 2. Aufl.. Stuttgart: Thieme, 2003.

Siewert, Jörg Rüdiger: Chirurgie. Berlin, Heidelberg: Springer, 2006.