Aneurysms
An aneurysm is a weakness in the wall of a blood vessel causing it to bulge out like a balloon. As the wall weakens, the pressure in the aneurysm increases and can potentially rupture and cause severe internal hemorrhage and death. Aneurysms can develop in any blood vessel, but is particularly dangerous when it develops in the aorta, the main blood vessel that carries blood from the heart to the rest of the body. Aneurysms can affect either the part of the aorta that runs through your chest (thoracic aorta) or the part that continues into the abdomen (abdominal aorta). Approximately 25 percent of aortic aneurysms occur in the chest, and the rest involve the abdominal aorta.An aortic dissection is another type of weakening in the wall of the aorta associated with high blood pressure. The pressure can rarely cause the layers of the wall of your aorta apart. This separation can extend from the thoracic aorta through your entire aorta and block arteries to your brain, intestines, kidneys and legs. Aortic dissection can, over time lead to aortic aneurysm.
Symptoms
Unfortunately, most aneurysms are asymptomatic and often the first presentation may be rupture and hemorrhage. Ruptured aneurysms are universally fatal unless treated promptly.Depending on location symptoms include:- Chest and/or Abdominal pain
- Back pain
- Coughing, hoarseness or difficulty breathing
- Feeling of a "heartbeat" or pulse in the abdomen
Symptoms of an acute dissection include a sharp, tearing pain in your chest or upper back. A chronic dissection compromising blood flow to vital organs can cause stroke, abdominal pain, kidney failure and leg pain.
If the aneurysm bursts, symptoms could include:
- severe back or abdominal pain that begins suddenly,
- paleness
- dry mouth/skin and excessive thirst
- nausea and vomiting
- signs of shock, such as shaking, dizziness, fainting, sweating, rapid heartbeat and sudden weakness
Risk Factors
- Atherosclerosis or hardening of arteries
- High blood pressure
- Smoking
- High cholesterol
- Family history
- Obesity
- Increasing age
- Motor vehicle injury and other forms of trauma
- Certain diseases such as Marfan's syndrome and bacterial infection of the aorta wall
The risk of rupture increases with increase in the size of the aneurysm and the rate of growth. Research has shown that abdominal aneurysms greater than 5cm and thoracic aneurysms greater than 6cm have a significant increase of rupture and should be repaired.
Diagnosis
Aneurysms are often initially diagnosed incidentally. This could include Xrays, ultrasound, CTScan and MRIs. Through its national screening program, Legs For LifeŽ, the Society of Interventional Radiology (SIR) has offered free screening for early detection and monitoring of AAA. Of those screened, 25 percent have been found to be at risk for AAATreatment Options
Repair of thoracic and abdominal aneurysms is a major procedure with significant complications. Small aneurysms are closely monitored, a process known as "watchful waiting". A CT or an MRI is obtained every 6 months to monitor the size of the aneurysm as well as its rate of growth. Aneurysms that are greater than 5 cm (6cm for thoracic), aneurysms that are rapidly growing (>1cm/year increase in widest diameter of aneurysm) or symptomatic aneurysms are prophylactically treated to prevent rupture.
Options for treating an aneurysm include open surgical repair and endovascular stent graft repair.
Open surgical is a major surgery requiring a surgeon to open up your chest or your abdomen or both, depending on the location of the aneurysm. A medical fabric material known as a graft, that is strong enough to prevent bulging of the aortic wall and hence prevent rupture is then used to replace the weakened portion of the aorta.
Some aneurysms, especially thoracic aneurysms can be extremely complex and may require additional heart surgery. Recovery from these major procedures may be from a few weeks to few months, depending on the complexity of the surgery and comorbid conditions.
Endovascular stent graft repair is a new way of treating aneurysms, in practice for over 15 years. This procedure utilizes the same rational as open repair i.e. fixing the bulge using a strong fabric. The difference is that, endovascular repair does not require a large incision or opening of your chest or the abdomen and hence recovery is much quicker and circumvents the complications of anesthesia for major surgery and comorbid conditions.
In this procedure an Interventional Radiologist, sometimes in collaboration with a surgeon will fix the aorta from the inside. This requires cutting edge technology and x-ray guidance under the expertise of an interventional radiologist. A small incision is made in your leg and small tubes called catheters are threaded from the leg artery to the aorta using x-ray guidance. These catheters carry a metal mesh tube (called a stent) with a graft material attached to it. Under careful X-ray guidance the stent with the graft material across the aneurysm, scaffolding it from the inside. The graft prevents the blood from ballooning the aorta, preventing rupture. Recovery from an endovascular repair is much shorter, usually two to three days.
Although a good portion of aneurysms can be treated endovascularly, some aneurysms have complex curves and hence a detailed consultation with your interventional radiologist is necessary to discuss treatment options. With endovascular stent graft repair, careful long-term follow-up with a CTScan or an MRI is important to assess proper functioning of the graft. Occasionally, fine-tuning of the graft is required; however, these are outpatient procedures and are usually quick without any major risks, when performed by an expert Interventional Radiologist.