Surgery for Aortic Aneurysm and Aortic Dissection
The aorta is the large artery that leaves the heart and provides oxygen-rich blood throughout the body.
Many diseases and conditions can cause the aorta to dilate (widen) or can cause aortic dissection (tear) increasing your risk for future life-threatening events. These conditions that can lead to aortic aneurysm and aortic dissection include:
- atherosclerosis (hardening of the arteries)
- hypertension (high blood pressure)
- genetic conditions (such as Marfan Syndrome)
- connective tissue disorders (such as Ehler-Danlos disorder, polychondritis, scleroderma, osteogenesis imperfecta, polycystic kidney disease, and Turners Syndrome)
What is aortic dissection and what causes it?
An aortic dissection is usually caused by high blood pressure. Aortic dissection is a condition that forces the layers of the wall of the aorta apart through increased blood flow. Over time, the pressure of the blood flow can cause the weakened area of the aorta to bulge like a balloon, stretching the aorta, causing aortic dissection and leading to severe, sharp, tearing pain in your chest and back.
When is surgery needed to treat aortic disease?
Surgery is needed to treat aortic disease for various reasons. A primary cause for surgery is when an artery wall in the aorta weakens and the wall abnormally expands or bulges as blood is pumped through it. This bulging is called an aortic aneurysm, and can lead to aortic dissection. An aneurysm can develop anywhere along the aorta:
- Aneurysms that occur in the section of the aorta that runs through the abdomen (abdominal aorta) are called abdominal aortic aneurysms.
- Aortic aneurysms that occur in the chest area are called thoracic aortic aneurysms and can involve the aortic root, ascending aorta, aortic arch or descending aorta.
- Aneurysms that involve the aorta as it flows through both the abdomen and chest are called thoracoabdominal aortic aneurysms.
Is an aortic aneurysm serious?
Aortic aneurysms are the 13th leading cause of death in the United States. Research has shown that patients with large thoracic aneurysms are more likely to die of complications associated with their aneurysms than from any other cause.
What types of surgery are used to treat aortic disease?
A variety of complex aortic surgery procedures are performed at Cleveland Clinic. Ascending aorta, aortic arch, descending aorta, thoracoabdominal repairs and thoracic aorta endovascular stent graft procedures are all performed by a multidisciplinary team.
During the last ten years, 21% of open great vessel procedures performed at Cleveland Clinic were for life-threatening acute aortic dissections.
What complex aortic procedures are used at Cleveland Clinic?
Cleveland Clinic surgeons have considerable experience and expertise in performing complex aortic operations, with just under 1,000 aorta procedures performed in 2008.
Hybrid Elephant Trunk Procedure
The hybrid elephant trunk procedure is one commonly used complex aortic operation recommended for patients who have extensive aortic aneurysms as well as several coexisting medical conditions, particularly respiratory problems.
The elephant trunk procedure is a two-stage procedure used to treat extensive aneurysms involving both the ascending aorta and aortic arch, and the descending thoracic or thoracoabdominal aorta.
Anatomic Illustration of Two-Stage Procedure
The elephant trunk procedure was used to treat a 65-year-old woman who had a leaking aneurysm, severe emphysema, and a leaky aortic valve.
In the first stage, Cleveland Clinic surgeons used a traditional incision in the sternum to replace the aortic valve, ascending aorta and arch, and placed an “elephant trunk” graft that hangs in the descending aorta. Shaped in a tubular form, the elephant trunk graft is made from Dacron, which is a synthetic material that is used to replace or repair blood vessels. The aorta was then wrapped at the diaphragm, and superior mesenteric arteries were bypassed. [View larger image]
During the second-stage procedure, a stent graft was placed by using an endovascular approach through the femoral artery to connect the elephant trunk to the lower wrap graft. [View larger image]
In other cases, an additional incision may be required to place an extra graft to another part of the aorta.
While a high-risk staged procedure, the current techniques used by Cleveland Clinic surgeons has resulted in a 98% survival rate for 142 patients having the first stage of the elephant trunk procedure and 92% survival for the second stage. Late survival was excellent with very low risk of reoperation.
The Valve-sparing Aortic Root Procedures
What is an aortic root aneurysm?
Occurring at the aortic root (the section of the aorta that is attached to the heart), an aortic root aneurysm can cause a life-threatening condition called aortic dissection. In this condition, blood flows through a tear in the inner layer of the aorta, causing the layers to separate. Blood flow becomes interrupted and causes the arterial wall to burst.
How is it treated?
The David’s valve-sparing aortic root replacement method is a surgical treatment for aortic root aneurysms. With this method, the aneurysm is repaired while the patient’s own aortic valve is preserved. If the patient’s aortic valve is diseased or cannot be used during the surgery, a bioprosthetic valve may be used.
What is the Modified David’s Reimplantation Procedure?
The Modified David’s Reimplantation Procedure, developed by Dr. Lars G. Svensson, Director of the Center for Aortic Surgery, Marfan Syndrome and Connective Tissue Disorders Clinic at Cleveland Clinic, is used to treat an aortic root aneurysm. While the David’s valve-sparing aortic root replacement method has many benefits, it is also a technically difficult procedure. Dr. Svensson’s Modified David’s procedure helps the surgeon determine the appropriately sized aorta graft, maintain the left ventricular outflow tract (the passageway out of the left ventricle), and improve outcomes when using the valve-sparing method.
With the Modified David’s approach, the surgeon uses a special piece of equipment called a Hegar’s dilator to ensure the outflow tract size of the aortic root is maintained, a more normal aortic root is established, and valve function is improved.
Cleveland Clinic Surgeons have performed over 120 Modified David Reimplantation procedures with no deaths and 97% freedom from reoperation at 10 years.
Cleveland Clinic surgeons are now able to treat some thoracic and thoracoabdominal aneurysms with a promising, new procedure called an endovascular stent graft.
What is an endovascular stent graft?
Endovascular means that surgery is performed inside the body using thin, long tubes called catheters. Through small incisions in the groin, the catheters are used to guide a stent graft through the blood vessels to the site of the aneurysm.
An endovascular stent graft is a small, wire mesh tube (also called a scaffold) that reinforces the weak spot in the aorta. By sealing the area tightly with the artery above and below the aneurysm, the graft allows blood to pass through it without pushing on the aneurysm.
What are the benefits of endovascular repair?
Endovascular repair of thoracic aneurysms is generally less painful and has a lower risk of complications than traditional open-chest surgery because the incisions are smaller.
The use of endovascular stent grafts is particularly beneficial for those patients who are not candidates for open-chest surgery, due to the risks it presents.
While a new and evolving approach, Cleveland Clinic surgeons are paving the way for successful use of endovascular repair of thoracic aneurysms, with careful attention to technique and type of stent graft used through various clinical trials.
Innovations advancing complex aortic surgery
For decades, Cleveland Clinic has been a world leader in medical breakthroughs and innovations. For example, two of the most important advances in modern cardiac care occurred at Cleveland Clinic. The first major contribution was the invention of coronary angiography in 1958. The next milestone was the first coronary artery bypass operation.
- Developed and refined at Cleveland Clinic beginning in 1967, coronary artery bypass has become the most common heart surgery in the world.
- Continued advances at Cleveland Clinic are enhancing complex aortic surgery, as well.
Ascending and Descending Aortic Aneurysm Repair
Complex aortic procedures treat patients with aneurysms that need replacement of the aorta from the aortic valve down to the aortic bifurcation (where the aorta separates into two).
The axillary artery is used to provide ongoing blood perfusion to organs during aortic aneurysm repair and when atherosclerosis (plaque) is present in the ascending aorta.
Cleveland Clinic surgeons offer an innovative approach for ascending and descending aortic aneurysm repair through a single operation that uses combined incisions in the chest and mid-abdomen. During the procedure, the axillary artery (the part of the main artery of the arm) is used to provide ongoing blood perfusion to the body’s organs, and is also used when atherosclerotic plaque is present in the ascending aorta.
Protecting the Brain
A recent study of 403 patients who underwent ascending and aortic arch minimally invasive operations over a 10-year period at Cleveland Clinic showed that blood conservation during surgery is beneficial for the prevention of stroke and neurocognitive outcome.
By following a preoperative protocol that includes patients donating 1 unit of autologous (their own) blood and fresh frozen plasma weekly before surgery (usually 3 to 4 units in total), and donating platelets 3 to 6 days before surgery to be used during the procedure, there was a 98.5% 30-day survival with only 2.0% occurrence of stroke.
While studies are ongoing as to the direct link that blood conservation has on brain function following replacement of the entire aortic arch or an endarterectomy (surgical removal of the lining of an artery), evidence from Cleveland Clinic studies and ongoing experience supports its use.
For More Information
- The Society of Thoracic Surgeons. “Aortic Aneurysms.” (2006). (Accessed 18 May, 2006)
- Vascular Web, Society for Vascular Surgery. “Thoracic Aneurysm.” (2006). (Accessed 18 May, 2006)
- Vascular Web, Society for Vascular Surgery. “Endovascular Stent Graft.” (Accessed 21 May, 2006)
- Ouriel, K, Greenberg, RK. Endovascular Treatment of Thoracic Aortic Aneurysms. J Card Surg, 2003; 18:455-463.
- Woo, JY, Bavaria, JE, Mohler, III, ER. Management and outcome of thoracic aortic aneurysm. (December 2005) www.uptodate.com
- Greenberg, RK, O’Neill, S, Walker E, Haddad F, Lyden SP, Svensson LG, Lytle B, Clair DG, and Ouriel K. Endovascular repair of thoracic aortic lesions with the Zenith TX1 and TX2 thoracic grafts: Intermediate-term results. Journal of Vascular Surgery, April 2005; 41:589-596.
- Svensson, LG, Kim KH, Blackstone EH, Alster JM, McCarthy PM, Greenberg RK, Sabik JF, D’Agostino RS, Lytle BW, Cosgrove DM. Elephant trunk procedure: newer indications and uses. Ann Thorac Surg, July 2004;78(1):109-16.
- Svensson, LG. The elephant trunk procedure: used in complex aortic diseases. Diseases of the aorta, pulmonary and peripheral vessels. Current Opinion in Cardiology, November 2005;20(6):491-95.
- Svensson, LG. Progress in ascending and aortic arch surgery: minimally invasive surgery, blood conservation, and neurological deficit prevention. Ann Thorac Surg 2002;74:S1786-S1788.
- Roselli EE, Greenberg RK, PFaff K, Francis C, Svensson LG, Lytle BW. Endovascular treatment of Thoracoabdominal aortic aneurysms. J. Thorac Cardiovascular Surgery. 2007 Jun; 133 (6): 1474-82. Epub 2007 May 2.