Aneurysms

Aneurysms are bulging sacs or pouches that develop on damaged or weakened areas of a blood vessel. Aneurysms are often filled with clotted blood or fluid, and can become infected.

An aneurysm can develop on any blood vessel, but aortic aneurysms and brain aneurysms are the most commonly diagnosed types. Should an aneurysm rupture, bleeding into surrounding tissue can cause serious damage and, in severe cases, even comas and sudden death.

Causes of Aneurysm

Certain risk factors and conditions increase the chances of a brain aneurysm or aortic aneurysm developing. These factors include:

Risk Factor Aneurysm Type
aging aortic aneurysm/brain aneurysm
aortitis aortic aneurysm
arteriosclerosis aortic aneurysm
cystic medial necrosis aortic aneurysm
family history of aneurysm aortic aneurysm/brain aneurysm
hypertension aortic aneurysm/brain aneurysm
infection aortic aneurysm/brain aneurysm
Marfan’s syndrome brain aneurysm
oral contraceptives brain aneurysm
polycystic kidney disease brain aneurysm
smoking aortic aneurysm/brain aneurysm
syphilis aortic aneurysm
trauma/injury aortic aneurysm/brain aneurysm

Symptoms of Aortic Aneurysm

The aorta and blood vessels branching off the aorta transport oxygen-rich blood through the body. Approximately 75 percent of aortic aneurysms develop in the abdominal aorta. The remaining 25 percent are thoracic aortic aneurysms, which develop in the chest.

An aortic aneurysm can grow particularly large prior to aneurysm rupture, and yet produce few or even no symptoms. When aortic aneurysm symptoms are present, a steady, deep pain may be felt. In the case of abdominal aortic aneurysms, the affected individual may be aware of abnormal abdomen pulsation. Thoracic aortic aneurysm can produce symptoms such as back pain, coughing, coughing up blood, hoarseness, difficulty breathing and wheezing.

Aortic aneurysm symptoms often develop just prior to aneurysm rupture. Excruciating pain develops, often in the abdomen and lower back. An aortic aneurysm rupture is a medical emergency that can rapidly result in shock and death.

Abdominal Aortic Aneurysm

Brain Aneurysm Symptoms

Prior to a rupture, a brain aneurysm is usually asymptomatic (lacking symptoms). On occasions when symptoms do develop prior to rupture, individuals may experience:

  • dilated pupils
  • double vision
  • headaches
  • pain around and behind the eye.

Just prior to an aneurysm rupture, forty percent of brain aneurysms cause the following symptoms:

  • blurry/double vision
  • headaches
  • light sensitivity
  • loss of sensation
  • nausea
  • stiff necks
  • vomiting.

Aneurysm Ruptures

Not all aneurysms rupture. In fact, an aortic aneurysm less than two inches in length (5 cm) is often monitored but not treated unless other health risks are involved. Aortic aneurysms over two inches in length require treatment.

Should an aneurysm rupture, complications can be fatal.

Aneurysm Type Aneurysm Rupture Complications
aortic aneurysm bleeding, shock due to loss of blood, circulation, organ damage, death.
brain aneurysm subarachnoid hemorrhage (bleeding into the space between the brain and skull), brain damage, paralysis, coma and death.

Aortic aneurysm rupture is the thirteenth leading cause of death in the US, killing over 15,000 Americans every year. Brain aneurysm ruptures affect 30,000 Americans annually.

If a brain aneurysm rupture involves severe bleeding, fifty percent of cases are fatal within minutes, and fifty percent of those who survive the initial rupture die from later complications.

Diagnosing Aneurysms

A physical examination for aortic aneurysm may reveal tenderness around the aneurysm, and stethoscopes may detect unusual blood vessel sounds, called bruits. Physical detection of an aortic aneurysm is difficult, however, so diagnostic tools must be used to confirm diagnosis. An ultrasound, CT scan and angiogram (an x-ray using contrast dye to highlight blood vessels) can all reveal an aortic aneurysm.

Brain aneurysms can also be detected by angiogram, or by using MRI scans (with or without contrast dyes). If a brain aneurysm rupture has occurred, a CT scan can reveal the extent of bleeding.

Aneurysm Repair and Treatment

If an aneurysm rupture occurs, emergency surgery is required to repair the rupture and prevent further bleeding. An unruptured aneurysm, however, may or may not require treatment.

For aortic aneurysms, surgical repair is usually recommended when the aneurysm is larger than two inches. Smaller aneurysms are monitored carefully for signs of growth or possible rupture, but surgical risks often outweigh the risks of treating a small aneurysm.

A number of factors determine whether a brain aneurysm should be surgically treated, including the size and location of the aneurysm, the patient’s health, family or personal history of aneurysms and the risk of a rupture.

Surgical repair treatments for aortic and brain aneurysms use similar techniques. Clipping is a technique in which small metal clips close off an aneurysm, preventing further expansion of the aneurysm and stopping bleeding if a rupture has occurred.

Occlusion is used to remove the portion of the blood vessel affected by the aneurysm while rerouting blood through other blood vessels. The removed section of blood vessel can also be replaced with a synthetic graft or a blood vessel removed from the leg.

Endovascular embolization, or coiling, is a less invasive aneurysm treatment. Catheters are threaded through blood vessels to the aneurysm site, and platinum coils are deposited into the blood vessels. The coils reduce (or completely block) blood flow to the aneurysm. Coiling allows a surgeon to treat a brain aneurysm when conventional surgery is impossible due to the aneurysm’s location.

The grafting or resectioning of blood vessels is major repair surgery, especially in the case of brain aneurysms, where a section of the skull must be temporarily removed. A new procedure, GORE TAG endoprosthesis, uses catheters to deliver a synthetic graft to the aneurysm site. Once positioned by the catheter, the graft is expanded, strengthening the artery wall and preventing a rupture. GORE TAG endoprosthesis has been used successfully to treat thoracic aortic aneurysms.

Resources

American Association of Neurological Surgeons. (2003). Treatment options for cerebral aneurysms.

Beers, M.H.