Aneurysm causes, symptoms, treatment and prevention gas constant for air


The most common location for aneurysms is the aorta, the body’s largest artery. The aorta carries blood from the heart downward to the abdomen, pelvis and lower body before branching into each leg. About 75 percent of aortic aneurysms occur in its lower section and are known as abdominal aortic aneurysms (AAAs). Aneurysms in the upper part of the aorta are called thoracic aortic aneurysms (TAAs).

Aneurysms can also affect the arteries that carry oxygen-rich blood to the brain. In appearance, brain aneurysms resemble a berry on a stem. About one person in 50 has a brain aneurysm, and in most cases, the condition doesn’t cause any health problems.

Most aneurysms develop slowly over months or years, though they can appear suddenly when an artery is damaged by trauma. As an aneurysm grows, it becomes more likely to rupture or leak. A ruptured aortic aneurysm can cause severe internal bleeding and rapid death due to blood loss. A ruptured brain aneurysm can bleed into the brain, causing a stroke. Hemorrhagic strokes damage brain cells, increase the pressure within the skull, and are likely to cause death or significant disability.

Blood clots, which tend to form around the aneurysm site, are another potential complication. A clot that breaks away from the artery wall can travel through the body and lodge in smaller arteries, causing a stroke, heart attack or pulmonary embolism.

Aneurysms are a significant public health problem. Ruptured AAAs kill about 14,000 Americans annually. About 27,000 Americans experience a ruptured brain aneurysm each year, and the majority of these cases result in death or disability. Causes

The underlying cause of an aneurysm is a weak spot in the artery wall. Over time, repetitive pounding by the blood as it’s forced through the veins with each heartbeat causes the weak spot to bulge. The higher the person’s blood pressure, the more likely an aneurysm is to form.

• Imaging tests – These are used to determine the size, shape and location of the aneurysm and to aid in treatment planning. The most common test is computed tomography (CT), which uses X-rays to visualize body structures in two-dimensional “slices.” Other useful tests include ultrasound, echocardiography and MRI. A contrast agent (dye) may be injected into the blood to improve clarity of the images.

• Angiography – In this test, a flexible tube called a catheter is inserted through an artery in the groin and threaded to the site of the suspected aneurysm under X-ray guidance. Contrast agent is then injected through the catheter, and a special X-ray machine is used to visualize the blood and arteries.

For small aneurysms with a low risk of rupture, the doctor and patient may agree to simply monitor the condition for while. The patient receives regular CT scans to check for growth or changes in the aneurysm. The patient may also be advised to avoid certain activities that can raise blood pressure, such as drinking caffeine or straining to lift a load.

Medication therapy can also be beneficial for people with aneurysms. Drugs called beta-blockers and calcium channel blockers can help to reduce blood pressure and relax the blood vessels. This makes the aneurysm less likely to grow or rupture.

• Open surgery – An incision is made above the aneurysm site. The bulging portion of the blood vessel is removed and replaced by a section of tubing. In the case of a brain aneurysm, a clip is placed around the “stem” of the aneurysm to seal it off from the artery.

• Endovascular surgery – The surgeon makes an incision into the artery at the groin and inserts a catheter. The catheter is threaded under X-ray guidance through the arteries to the location of the aneurysm. A tube called a stent is then passed through the catheter and placed inside the aneurysm. The ends of the stent are sealed to the healthy blood vessel walls on either side of the aneurysm. This “bypass” prevents rupture and promotes healthy blood flow.

• Endovascular coiling – This is a specialized endovascular procedure that’s used to treat brain aneurysms. A catheter is inserted and guided through the aorta and into the brain arteries. A special coil in the catheter’s tip initiates a clotting reaction inside the “berry” part of the brain aneurysm. The clot fills the “berry” and seals off the opening through the “stem,” preventing rupture.

People who have experienced a brain hemorrhage may need additional surgery to relieve pressure inside the skull. This usually involves placement of a special catheter that drains excess fluid to an external collection bag or into the patient’s abdomen, where the body reabsorbs it.

The prognosis for aneurysm patients is generally good when the condition is diagnosed early, monitored and treated. However, ruptured aneurysms often have serious or fatal consequences. Only about 20 percent of patients survive rupture of an AAA. Ruptured brain aneurysms are fatal in about 40 percent of cases, and about two-thirds of survivors experience some form of permanent disability. Prevention