Types of AneurysmsThe two types of aortic aneurysm are abdominal aortic aneurysm and thoracic aortic aneurysm. Some people have both types. Simply stated, an aneurysm is a widening of an artery. These can occur anywhere in the body from an artery in the foot to an artery in the brain. We, at The Cardiovascular Care Group, specialize in the diagnosis and management of all Aneurysms outside of the brain. The most common location for an aneurysm to occur outside of the brain is in the main artery in the stomach—the abdominal aorta. Abdominal Aortic Aneurysms (“AAA”) can be lethal if not recognized and treated. The “normal size” (diameter) of the abdominal aorta is approximately one inch (2.5 cm.) Typically an artery is recognized to have an aneurysm when its diameter increases by 50%, which would be about 1.5″ or approximately 4cm from side to side. Arteries behave much like water balloons—that is, the bigger they get, the thinner they get. The thinner they get, the more chance there is of the artery popping or rupturing. A ruptured abdominal aortic aneurysm (AAA) is often fatal as the ruptured artery leads to massive internal bleeding and usually immediate death from exsanguination. Smaller aneurysms are less likely to rupture than larger ones. Typically, when an aneurysm reaches 5cm, consideration is given to repairing the artery to prevent rupture. The exact size at which an aneurysm should be repaired varies from patient to patient. While some aneurysms are fixed when they reach 5cm, some physicians will watch the patient closely until it gets to be larger—sometimes even 6cm or 7cm depending on the size of the patient or their other medical conditions. A 6’8″, 275 pound football player, might have a normal aorta that measures 3 cm so that 5 cm might not be relatively large for that individual, However, a 5′, 100 pound woman might have a normal aorta that measures only 2cm and, therefore, 5cm is 2 ½ time normal making that 5cm widening very dangerous. The determination to repair the aneurysm is made by assessing the risk of the operation to repair the problem versus the risk of that aneurysm rupturing or bursting without the operation. Experience is critical in making that assessment as is having a thorough knowledge of all of the options available for repair. The Cardiovascular Care Group has been managing patients with AAA for over fifty years and we were one of the first physicians to apply minimally invasive stent graft technology to the repair of abdominal aortic aneurysms.
DiagnosisWhile technology has improved the ease of diagnosis of AAA, an “old-fashioned” history and physical examination are critical in the assessment and diagnosis of this problem. Abdominal aortic aneurysms do tend to “run in families”–hence, genetics are important. Interestingly, when there is a female in the family that has had an AAA, this tends to be more familial than a male relative. Patients with chronic lung disease (COPD) seem to be at higher risk for rupture of an AAA than others and those with a history of smoking also seem to be at risk. Hypertension (high blood pressure) is another independent risk factor for aneurysms. A careful examination of the abdomen can identify an AAA in thinner patients. Unfortunately, in patients who have a more rotund abdomen, the physical examination is less reliable as the aneurysm may be impossible to feel—even by the trained physician. Many AAAs are found incidentally when tests are performed for other reasons. It is not uncommon for patients to have an x-ray for back pain or a CT Scan for an unrelated reason (for example, looking for prostate disease or trying to determine the cause of abdominal pain) and the radiologist will find an AAA. It is very uncommon for an aneurysm itself to cause pain (unless it has ruptured) and thus the surprise when it is found during a test looking for something else. The Noninvasive Vascular Laboratory is one of the most reliable and safest places to diagnose and follow an abdominal aortic aneurysm. Using ultrasound, the AAA can be seen and measured. Ultrasound does not use radiation and is safe and accurate when performed by an experienced Registered Vascular Technologist such as those at The Cardiovascular Care Group. It is important for the test to be done in an accredited laboratory, as the size of the AAA is critical in determining the management. Quite frequently, an AAA can be safely watched over time to see if it is growing and at what rate it is expanding ( if at all.) Since a few millimeters can make a difference, repeating the test at predetermined intervals by the same laboratory is extremely important. Vascular Laboratories specialize in this examination and should be utilized for this purpose. Other test, such as CT Scans and Magnetic Resonance Imaging (MRI) also allow for the diagnosis of AAA. These tests, however, require radiation (CT scan) and the use of contrast (dye) that makes them more invasive than an ultrasound. However, they are invaluable once the decision has been made to proceed with surgery as they provide information that is important in the decision-making process that might not be available with the use of ultrasound technology.
Treatment of Abdominal Aortic Aneurysms Overview
The most critical part of the treatment of AAA is deciding when (and if) surgery is needed. This is a complex decision as the repair of an AAA is a significant undertaking. The overall medical condition of the patient must be considered with particular attention paid to health of the individual’s heart and their ability to undergo anesthesia.
Historically, aneurysm repair has required a major operation to replace the weakened part of the abdominal aorta. An incision in the abdomen allows the surgeon to access the aortic and sew in a cloth tube extending from healthy aorta above the aneurysm to normal arteries below. This typically requires a 4-7 day hospital stay with a significant recuperation period thereafter. Once repaired, the chance for recurrence of the AAA, is extremely small.
More recently (since the 1990s), stent graft technology has dramatically changed the management of AAAs. Rather than a major operation with a long incision, the use of aortic stent grafts can be done with two small groin incisions or with only a puncture with a needle! Rather than a 4-7 day hospital stay, patients can now be treated with a one-day hospital stay—some even returning home on the same day of the AAA repair! The post-operative recuperation is much easier and the pain significantly minimized. Through each groin, the stent graft is passed through the arteries to a point just above the AAA and deployed. The majority of the abdominal aortic aneurysms repaired at The Cardiovascular Care Group are performed using this technology.
Patients whose AAA is repaired with a stent graft do require careful office follow-up for the remainder of their life. Routine ultrasound examinations are necessary to insure that the stent graft is functioning well and no problems develop.
Once again, experience and judgment are crucial to the management of AAA. Five decades of experience combined with cutting edge technology make The Cardiovascular Care Group unique in its ability to manage patients with Abdominal Aortic Aneurysms!