For decades, CVTSA surgeons repaired thoacic aortic aneurysms through open, complex and long operations. Thanks to advances in medical technology, many patients are now candidates for minimally invasive surgical repair. Our thoracic aortic aneurysm surgeons have been performing minimally invasive thoracic aortic aneurysm surgery on patients from Virginia, Maryland and Washington, DC, since they were introduced to the market three years ago. In fact, CVTSA surgeons have one of the largest experiences with this surgery on the east coast. To make an appointment, call (703) 280-5858.
What is a Thoracic Aneurysm?
A thoracic aortic aneurysm is a bulging, weakened area in the wall of the aorta (the largest artery in the body), resulting in an abnormal widening or ballooning greater than 50 percent of the normal diameter (width).
What is the Aorta?
The aorta is main artery out of your body and feeds blood to the body and heart.
The wall of the aorta is quite elastic and consists of three layers that stretch to accommodate the pulsation of blood flowing into the artery as the heart contracts. The aortic wall is lined with a thin layer of smooth cells, the middle layer is a thick muscular layer that is surrounded by a tough outer layer of connective tissue.
The aorta extends upward from the top of the left ventricle of the heart in the chest area (ascending thoracic aorta), then curves like a candy cane (aortic arch) giving rise to the three branches: to the right arm and right side of the brain, left side of the brain, and the left arm.
The arch is the transitional part of the aorta that extends from the front of the chest to the back of the chest. The aorta then straightens out and extends downward through the chest area (descending thoracic aorta) into the abdomen (abdominal aorta).
The vessels that supply the spinal cord originate from the descending thoracic aorta, made up of the ascending aorta, the arch of the aorta, and the descending aorta.
What is the Abdominal Aorta?
The abdominal aorta is that part of the aorta below the diaphragm that gives rise to the abdominal organs and kidneys before dividing into two branches (iliac arteries) that carry the blood to the legs. The aorta, in summary, delivers oxygenated blood pumped from the heart to the rest of the body.
How are Aneurysms Differentiated?
Aneurysms are characterized by their location, shape, and cause.
A thoracic aortic aneurysm is located in the chest area and can involve the ascending, arch, or descending thoracic aorta. The thoracic aorta can be divided into segments:
An aneurysm may be located in one of these areas and/or may be continuous throughout the aorta. An aneurysm called a thoracoabdominal aneurysm involves a thoracic aortic aneurysm extending down to and involving the abdominal aorta.
These aneurysms are relatively rare and the treatment may involve replacement of the entire aorta. This complex surgical procedure may involve reconnecting the branch vessels to the spinal cord, the vessels to the visceral organs and possibly reconnecting the vessels to the kidneys. Specific and excellent technical expertise is required and this procedure may be limited to those centers with such skills.
Thoracic aneurysms do not occur as often as abdominal aneurysms. The descending thoracic aorta is the most common location of a thoracic aneurysm, followed by the ascending segment, then the arch. The location of an aneurysm is distinctly connected with the cause, course, and treatment of a thoracic aneurysm.
The larger the aneurysm, the greater the risk of rupture or tear within the wall of the aorta (aortic dissection). Approximately one-third of patients with a thoracic aortic aneurysm larger than 2.3 inches (5 cm) in diameter may die within 5 years from rupture or dissection if the aneurysm is not treated. If the aneurysm is diagnosed and surgically treated, these fatal complications may be averted and the patients may expect a normal life span.
Types of Thoracic Aortic Aneurysms:
The shape of an aneurysm is described as being fusiform or saccular which helps to identify a true aneurysm. A true aneurysm involves all three layers of the arterial blood vessel wall. The more common fusiform-shaped aneurysm bulges or balloons out on all sides of the aorta. A saccular-shaped aneurysm bulges or balloons out only on one side. Many saccular aneurysms may be caused by trauma such as a motor vehicle accident or are the result of a penetrating aortic ulcer.
A pseudoaneurysm, or false aneurysm, is an enlargement of only the outer layer of the blood vessel wall. A false aneurysm may be the result of prior surgery or trauma. Sometimes, a tear may occur on the inside layer of the vessel resulting in blood entering the layers of the blood vessel wall, creating a pseudoaneurysm.
Once formed, an aneurysm will gradually increase in size and there will be a progressive weakening of the aneurysm wall. This is dangerous because the aorta is under constant pressure from blood being ejected from the heart. With each heartbeat, the walls of the aorta expand and spring back, exerting continual pressure or stress on the already weakened aneurysm wall.
Therefore, there is a potential for rupture (bursting) or dissection (separation of the layers of the thoracic aortic wall), which may cause life-threatening hemorrhage (uncontrolled bleeding) and, potentially, death.
Treatment may include surgical thoracic aneurysm repair or removal of the aneurysm to prevent rupture.
What causes a Thoracic Aortic Aneurysm to Form?
Thoracic aortic aneurysms may be caused by different disease processes, especially in respect to their location. Examples of different locations of thoracic aortic aneurysms and their causes may include, but are not limited to, the following:
What are the Symptoms of a Thoracic Aortic Aneurysm?
Thoracic aortic aneurysms may be asymptomatic (without symptoms) or symptomatic (with symptoms). Symptoms of a thoracic aneurysm may be related to the location, size, and growth rate of the aneurysm.
Severe onset of pain associated with a thoracic aneurysm may be a sign of a life-threatening medical emergency.
Symptoms of an ascending thoracic aneurysm may include, but are not limited to, the following:
- pain in the chest, neck, and/or back
- swelling of head, neck, and arms as a result of pressure on large blood vessels
- heart failure - an ascending aneurysm may affect the heart valves, causing blood to back up into the heart
Symptoms of an aortic arch aneurysm or a descending thoracic aneurysm may include, but are not limited to, the following:
- wheezing, coughing, or shortness of breath as a result of pressure on the trachea (windpipe)
- coughing up blood (hemoptysis)
- hoarseness as a result of pressure on the vocal cords
- difficulty swallowing (dysphagia) due to pressure on the esophagus
- pain in the chest and/or back
The symptoms of a thoracic aortic aneurysm may resemble other conditions. Consult your physician for a diagnosis.
How is a Thoracic Aortic Aneurysm Diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for a thoracic aortic aneurysm may include any, or a combination, of the following:
- computed tomography scan (also called a CT or CAT scan.) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than standard x-rays.
- magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
- echocardiogram (also called echo) - a procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce a moving picture of the heart and heart valves, as well as the structures within the chest, such as the lungs, mediastinum (area in the chest containing the heart, aorta, trachea, esophagus, thymus, and lymph nodes), and pleural space (space between the lungs and the interior wall of the chest).
- transesophageal echocardiogram (TEE) - a diagnostic procedure that uses echocardiography to assess the presence of an aneurysm, the condition of heart valves, and/or presence of a dissection (tear) of the lining of the aorta. TEE is performed by inserting a probe with a transducer on the end down the throat.
- chest x-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
- arteriogram (angiogram) - an x-ray image of the blood vessels used to evaluate various conditions, such as aneurysm, stenosis (narrowing of the blood vessel), or blockages. A dye (contrast) will be injected through a thin flexible tube placed in an artery. The dye makes the blood vessels visible on an x-ray.
Treatment for Thoracic Aortic Aneurysm:
Specific treatment will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the disease
- your signs and symptoms
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment may include:
- routine MRI or CT - to monitor the size and rate of growth of the aneurysm
- controlling or modifying risk factors - steps such as quitting smoking, controlling blood sugar if diabetic, losing weight if overweight or obese, and controlling dietary fat intake may help to control the progression of the aneurysm
- medication - to control factors such as hyperlipidemia (elevated levels of fats in the blood) and/or high blood pressure
- thoracic aortic aneurysm surgery
Thoracic Aortic Aneurysm Open Repair
The type of thoracic aortic aneurysm repair will depend on several factors: the location of the aneurysm, the type of aneurysm, and the patient's tolerance for the procedure. For an ascending or aortic arch aneurysm, a large incision may be made through the breastbone (median sternotomy). If an ascending aneurysm involves damage to the aortic valve of the heart, the valve may be repaired or replaced during the procedure. For a descending aneurysm, a large incision may extend from the back under the shoulder blade around the side of the rib cage to just under the breast (thoracotomy). These approaches allow the surgeon to visualize the aorta directly to repair the aneurysm.
Endovascular Aneurysm Repair (EVAR)
EVAR is a procedure which requires only small incisions in the groin, along with the use of x-ray guidance and specially-designed instruments to achieve thoracic aneurysm repair by inserting a tube, called a stent-graft, inside the aorta. At this time, the only thoracic aneurysms repaired by means of EVAR are descending thoracic aneurysms.
Asymptomatic aneurysms may not require surgical intervention until they reach a certain size or are noted to be increasing in size over a certain period of time. Parameters considered when making surgical decisions include, but are not limited to, the following:
- aneurysm size greater than 5.5 to 6 centimeters (greater than two inches)
- aneurysm growth rate 0.5 centimeters (slightly less than one-fourth inch) over a period of six months to one year
- presence of genetic disorders or familial history of thoracic aneurysms
- patient's ability to tolerate the procedure
For symptomatic aneurysms, immediate intervention is indicated.
What is Aortic Dissection?
An aortic dissection begins with a tear in the inner layer of the aortic wall, usually in the ascending or descending thoracic aorta. The aortic wall is made up of three layers of tissue. When a tear occurs in the innermost layer of the aortic wall, blood is then channeled into the wall of the aorta separating the layers of tissues. This generates great pressure in the aortic wall with a potential to rupture (burst). Aortic dissection can be a life-threatening emergency.
Is there a Minimally Invasive Treatment of Thoracic Aortic Aneurysms?
When a thoracic aortic aneurysm is considered dangerous and at increased risk for leak or rupture, the standard treatment has traditionally been by an operation performed through a large incision in the breastbone (sternum) or the side (thoracotomy). The aneurysm is repaired by replacing the diseased aorta with a Dacron graft that is sewn into place with sutures. The procedure may require using the heart-lung machine as the blood flow to the spinal cord or vital organs has to be stopped while the graft is being put into place. These are some of the most invasive surgical procedures performed in cardiac surgery and are accompanied by significant risks of death, stroke, weakness of the legs (paraplegia), bleeding and kidney failure that might require dialysis.
A relatively new, less invasive procedure has become available for the treatment of some thoracic aortic aneurysms and is being offered by the surgeons in CVTSA.
This treatment involves excluding the aneurysm by placing an endovascular graft inside of the diseased aortic aneurysm. This endograft in effect creates a new lining so that the blood flow is no longer in contact with the thoracic aneurysm and there is no longer any pressure being exerted onto the wall of the thoracic aortic aneurysm. This endovascular stent graft remains permanently inside of the aorta, held into place by a metal stent that creates a tight seal against the wall of the aorta.
While open surgical repair requires a general anesthesia, the endovascular repair may be performed under general, regional, or local anesthesia. The catheters required to deliver the endovascular stent graft are placed into the femoral arteries in the groin through small incisions instead of the large incisions in the breastbone or side of the chest. The procedure takes one to three hours to complete. The hospital stay may be much shorter than the open surgical procedure - many patients may stay only several days.
Follow-up for patients who have had insertion of an endovascular aortic stent graft in the thoracic aorta includes check-ups at 1 month, 6 months, 12 months, and annually thereafter.
Follow-up exams consists of chest x-rays, CT Scans and a physical exam. These are performed because they are necessary to evaluate the outcome of the treatment and any changes over time, as the long-term results, safety, and overall effectiveness of endovascular repair has not been established.
Some patients may require additional treatment for endoleak (blood flow that continues to occur around the graft into the aneurysm), continued aneurysmal growth, or vessel occlusion.
Advantages to Minimally Invasive Treatment
In a nationally conducted trial of the endovascular stent grafts (Pivotal Trial for the GORE TAG Thoracic Endoprosthesis) there were advantages demonstrated to the minimally invasive procedure vs. the open surgical repair. These advantages held true even in centers such as ours with excellent open surgical results. The results showed decreased weakness in the legs, decreased mortality, less procedural blood loss on average, shortened ICU and hospital length of stay, and earlier return to work as compared to open surgical repair.
Located just off the Beltway and Rt. 50 in Falls Church, VA, CVTSA proudly serves patients in Virginia, Maryland and DC in need of thoacic aortic aneurysm repair. To schedule an appointment, please call (703) 280-5858.