An aneurysm is an abnormal swelling or bulge in the wall of a blood vessel, such as an artery. It begins as a weak spot in the blood vessel wall, which balloons out of shape over time by the force of the pumping blood. Usually, aneurysms develop at the point where a blood vessel branches, because the ‘fork’ is structurally more vulnerable.Aneurysms are potentially fatal if they rupture. Death can occur within minutes.
An aneurysm can occur in any part of the body. They tend to most commonly occur on the wall of the aorta - the large trunk artery that carries blood from the left ventricle of the heart to branch arteries. The aorta goes down through the chest and into the abdomen, where it divides into the iliac arteries (two branches). There are two main types of aneurysms:
- Aortic aneurysm - occurs in the aorta. Can be abdominal, or thoracic (higher up).
- Cerebral aneurysm - occurs in an artery in the brain.
What are the symptoms of an aneurysm?
Symptoms are linked to how big the aneurysm is, how fast it is growing and its location. Very small aneurysms which do not grow may go completely unnoticed. A large cerebral aneurysm (in the brain) may press on nerve tissue and trigger numbness in the face, or problems with the eyes.
Cerebral (brain) aneurysm symptoms
The following symptoms may be experienced before a cerebral aneurysm ruptures:
- Very severe headache that occurs suddenly
- Eyesight problems
- Seizures (fits)
- Loss of consciousness
- A drooping eyelid
- Stiff neck
- Light sensitivity
Aortic aneurysm symptoms
The vast majority of aortic aneurysms occur in the patient's abdominal aorta. It is not uncommon for a patient to have an aneurysm and experience no symptoms for several years. Many of them are difficult to detect because of this. Some aortic aneurysms will never rupture. It is hard to predict which ones will never grow, which grow slowly, and which ones grow rapidly.
When symptoms occur, they tend to include:
- A throbbing sensation in the abdomen
- Back pain
- Abdominal pain - this pain frequently spreads towards the back If the aneurysm continues to grow and presses on the spine or chest organs the patient may experience:
- Loss of voice
- Breathing difficulties
- Problems swallowing
What causes an aneurysm?
Brain (cerebral) aneurysm causes:
- Weakness in the artery wall (usually present since birth)
- Hypertension (high blood pressure)
- Arteriosclerosis (plaques of cholesterol, platelets, fibrin, and other substance form on the arterial wall)
Abdominal aortic aneurysm causes:
- Atherosclerosis - accumulation of fatty deposits (cholesterol) on the artery walls.
- Smoking - this is a major risk factor in the development of aortic aneurisms. Smoking contributes to atherosclerosis, hypertension and the acceleration of aneurysm growth. Compared to women who have quit smoking, women smokers are four times more likely to have an abdominal aortic aneurysm repair or ruptura.
- Hypertension - especially if it is poorly controlled (not treated at all, or not treated properly).
- Vasculitis (infection in the aorta) - this is an uncommon cause, and seems to run in families.
- Cocaine use - Cocaine users in their mid-40s had more than four times the risk of coronary artery aneurysms as non-users.
Thoracic aortic aneurysm causes:
About 1 in 4 aortic aneurysms occur in the thoracic area of the aorta (higher up in the chest). Causes are the same as with aortic aneurysms, plus the following below:
- Marfan syndrome - this is a genetic disorder of the connective tissue; it is a much less common cause of aortic aneurysm.
- Previous aorta injury - people with a previous injury to the aorta, such as aortic dissection (tear in the wall of the aorta) have a higher risk of developing a thoracic aortic aneurysm.
- Traumatic injury - this could be cause by a vehicle accident or a bad fall.
- Physical examination
- Ultrasound scans
- Computed tomography (CT) scans/CTA
- Occasionally MRIs
- Examination of cerebrospinal fluid (for a diagnosis of a subarachnoid haemorrhage).
Treatment for an aneurysm
- The aim is to prevent the aneurysm from bursting. There are usually two choices -
- 1. Watch and wait.
- 2. Surgery. How big the aneurysm is, how fast it's growing, and sometimes its location are vital factors in determining what treatment to use.
Small observational studies have suggested that statins can significantly reduce the growth rate of small abdominal aortic aneurysms.
If the aneurysm is medium-sized - a medium-sized aneurysm is no bigger than 2.2 inches (5.5 cm) in diameter and bigger than 1.6 inches (4 cm). It is more difficult now to weigh up the risks of surgery against the risks of a medium-sized aneurysm. The chances of both patient and doctor deciding on one or the other are pretty even.
Endovascular surgery - this is a less invasive procedure to repair an aneurysm. A graft is attached to the end of the catheter which is inserted through an artery and threaded up into the aorta. The graft - consisting of a woven tube covered by a metal mesh support - is placed at the site of the aneurysm and stuck there will pins or small hooks. This graft strengthens the weakened section of the aorta and prevents the aneurysm from rupturing. Patients recover much faster with this procedure, and seem to have fewer complications.
Long-term survival for patients undergoing surgical repair of intact abdominal aortic aneurysms has improved in recent decades.
- Surgery is usually required as soon as the aneurysm reaches a diameter of 2.2 inches (5.5 cm). Patients with Marfan syndrome, as well as those with close relative who had an aortic dissection may undergo surgery if the aneurysm is smaller. Beta blockers have been shown to slow down the growth of thoracic aortic aneurysms for patients with Marfan syndrome.
- Cerebral (brain) aneurysm treatment:
- Ruptured cerebral aneurysm treatment
- Patients with brain aneurysms have two options if the aneurysm has ruptured:
- 1. Surgical clipping.
- 2. Endovascular coiling.
- Surgical clipping - the aneurysm is closed off. The surgeon removes a section of the skull to get to the aneurysm and finds the blood vessel that feeds it. A tiny metal clip is placed on the neck of the aneurysm to block off the blood flow to it.
- Endovascular coiling - a catheter is inserted, usually in the groin, and is threaded through the body to the brain where the aneurysm is located. A guide wire is used to push a soft platinum wire through the catheter and into the aneurysm. The wire coils up inside the aneurysm and disrupts the blood flow, making it clot. The clotting of the blood effectively seals off the aneurysm from the artery.
- Endovascular, noninvasive thoracic aortic aneurysm repair (TEVAR) is safer than open aneurysm repair (OAR) as it is associated with fewer cardiac, respiratory, and hemorrhagic complications, as well as a shorter hospital stay.
Patients whose aneurysms are coiled instead of clipped have a better survival rate over five years.
Smokers who undergo coil embolization are at a high risk of having another aneurism elsewhere later on.
- Painkillers - usually for headaches.
- Calcium channel blockers - these stop calcium for entering cells of the blood vessel walls. They reduce the amount of widening and narrowing of blood vessels; often a complication of a ruptured aneurysm.
- A vassopressor - this is an injected drug which raises blood pressure; widens blood vessels which have remained stubbornly narrowed. The aim is to prevent stroke.
- Anti-seizure drugs - seizures may occur after an aneurysm has ruptures. Examples include levetiracetam (Keppra), phenytoin (Dilantin, Phenytek, others) and valproic acid (Depakene).
- A ventricular catheter - this can reduce the pressure on the brain caused by hydrocephalus (excess cerebrospinal fluid). The catheter, which is placed in the spaces filled with fluid inside the brain, drains the excess liquid into an external bag. It may be necessary to place a shunt system - a shunt (flexible silicone rubber tube) and a valve. The shunt system is a drainage channel that starts in the brain and ends in the patient's abdominal cavity.
- Rehabilitation therapy - sometimes a subarachnoid hemorrhage causes brain damage, resulting in impaired speech and bodily movements. Rehabilitation therapy helps the patient relearn vital skills.
- The unruptured cerebral aneurysm can be sealed off with surgical clipping or endovascular coiling. Deciding on this is not easy as the risks are often equal, and sometimes higher than the potential benefits.
- The following will help the surgeon determine what to do:
- Exactly where the aneurysm is.
- How big the aneurysm is.
- The patient's age.
- The patient's general state of health
- Whether the patient has a family history of ruptured aneurysms.
- Whether the patient has any congenital conditions which may raise the risk of the aneurysm rupturing.
High risk of complications
Depending on the location of the aneurysm, some of the possible complications of an untreated aneurysm include:
- Blood clots within the aneurysm
- Compression of nearby nerves, if the aneurysm is large enough
- Blood leaking out of the intact aneurysm into the walls of the artery (dissecting aneurysm)
- Impaired blood circulation beyond the point of the aneurysm
- Haemorrhage in the layers of tissue surrounding the brain (subarachnoid haemorrhage)
- Water on the brain (hydrocephalus)
- Congestive heart failure
- Heart attack
- Kidney failure
- Sudden death
With successful surgical repair, the outlook is often excellent.Things to remember
Do not smoke. If you do, quitting will lower your risk of an aneurysm.
Do not smoke. If you do, quitting will lower your risk of an aneurysm.
Call your doctor for if you develop a lump on your body, whether or not it is painful and throbbing
An aneurysm is an abnormal swelling or bulge in the wall of a blood vessel, such as an artery.