An aneurysm is a bulging out of part of the wall of a blood vessel. Aneurysms occur in several different forms. Saccular aneurysms protrude from the wall of the artery, like a berry. They may occur singly or in groups. Risk factors for saccular aneurysms include high blood pressure (hypertension), cigarette smoking and various diseases of the connective tissue. Fusiform aneurysms are characterized by the enlargement of the entire artery. They are often a complication of atherosclerosis, or a buildup of plaque in the artery.
Unfortunately, aneurysms do not typically produce symptoms. In many cases, the first symptoms of an aneurysm occur after the aneurysm bursts. However, various imaging tests can detect aneurysms, enabling their treatment before a medical emergency occurs.
Left untreated, aneurysms may tear or burst (a ruptured aneurysm). Ruptures are very painful events that cause massive internal bleeding and may result in permanent disability or death, depending on where the aneurysm is located. Ideally, aneurysms are diagnosed before rupture, allowing physicians the opportunity to treat it and hopefully prevent a rupture. Aneurysms can be treated with surgery to remove the weakened portion of the arterial wall, or with specialized stent-grafts that are permanently implanted in the artery to route blood around the aneurysm. Other devices to treat aneurysms include tiny coils that are delivered via catheter and cause a blood clot in the aneurysm, thus sealing it off. In some cases, aneurysms will be closely monitored instead of aggressively treated, to see if the aneurysm is stable as opposed to expanding in size.
If the aneurysm ruptures, the outcome depends on its location. If an aneurysm bursts in the brain, it could cause a hemorrhagic stroke. If an aneurysm bursts in the aorta, the body’s main artery that runs from the heart down through the chest and abdomen, there is an immediate medical emergency. More than half of people with aortic aneurysms do not survive the event. Therefore, early diagnosis and treatment before the aneurysm bursts are critical. Because aortic aneurysms often produce no symptoms or mild symptoms (e.g., back pain), routine physical examinations are strongly encouraged so that a physician can regularly test for warning signs. Patients with a family history of aneurysms should be screened for aneurysm.
There are a number of different types of aneurysms, which include:
Aortic aneurysm. A very dangerous condition characterized by the distention, or ballooning out, of part of the wall of the aorta. Aortic aneurysms may occur in the chest (thoracic aortic aneurysm) or abdomen (abdominal aortic aneurysm). An aneurysm is usually diagnosed when the enlarged portion of the aorta is 1.5 times its normal size. If accompanied by an aortic dissection, it is classified as a dissecting aortic aneurysm.
Cerebral aneurysm. A cerebral aneurysm is a bulge in the wall of a blood vessel in the brain (one of the cerebral arteries). A cerebral aneurysm is typically found where the arteries branch at the base of the brain. There are various kinds of cerebral aneurysms, including berry aneurysms. As the name implies, these aneurysms are shaped like hanging berries. The cause is unknown, but smoking increases a person’s risk of developing this condition.
Ventricular aneurysm. A bulging or ballooning out of part of the wall of one of the heart’s lower chambers (ventricles), usually the left. If the aneurysm is present in the wall between the ventricles (the ventricular septum), it is also known as a ventricular septal aneurysm, an interventricular aneurysm or simply a septal aneurysm. It may be present since birth (congenital) or may be a complication of a heart attack or other trauma.
Atrial aneurysm. A bulging or ballooning out of part of the wall of one of the heart’s upper chambers (atria). If the aneurysm is present in the wall between the atria (the atrial septum), it is also known as an atrial septal aneurysm (ASA), an aneurysm of septum primum or an aneurysm of the septum secundum. An ASA has been associated with an increased risk of stroke and is often accompanied by the presence of a patent foramen ovale (PFO), an opening between the upper chambers (atria) of the heart. Normally, this opening is present in the developing fetus and closes shortly after birth. It is often present since birth (congenital).
Cirsoid aneurysm. The enlargement of a network of blood vessels that commonly occurs on the scalp and may result in the formation of a tumor.
Strategies for preventing an aneurysm include managing high blood pressure and preventing the buildup of plaque. Once an aneurysm has been detected, treatment depends on the size of the aneurysm and its location. It may be closely monitored to see if it is growing in size. Treatment options include surgery or implantation of devices that cause a blood clot to form in the aneurysm, thus sealing it off from additional, turbulent blood flow and reducing the risk of rupture.