Winter 2009
Study suggests survival rates improve when
more
options available for aneurysm repair
Alternatives, setting are key
Ruptured aortic aneurysm is the 10th leading cause of death in men over age 50 in the United States. Many cases of ruptured aneurysm can be prevented with early diagnosis and medical treatment.
The authors of the Austrian study have shown that by careful selection of patients by surgeons that are expert in both open and endovascular repair, outcomes can be superior. These excellent results can be expected when all options (both endovascular and open) are readily available and there are experienced vascular surgeons available to provide immediate care.
Surgical treatment of AAA has been performed routinely in the U.S. for about 50 years. It is a very successful and durable procedure. Recent advances in catheter-based technologies have led to exciting new treatments for aortic aneurysms. Now, endovascular grafting technology allows the repair of the AAA by inserting a graft through a small incision in the groin. The endovascular method allows the graft to be delivered through a catheter or tube inserted in a groin artery. X-ray guidance is then used to accurately position the graft in the AAA. The graft is then expanded inside the aorta and held in place with metallic hooks rather than sutures. The hospital stay is usually only one or two days, and most patients can return to work or normal daily activities in about a week.
Where a person receives their care for an abdominal aortic aneurysm makes a difference. As part of a large, teaching hospital, Yale-New Haven surgeons have experience with newer devices and techniques not available at other institutions. Yale-New Haven vascular surgeons have been performing minimally invasive endovascular aneurysm repair for several years, and are participating in several clinical trials related to this disease. As a result, we are able to provide minimally invasive treatments that are unavailable anywhere else in Connecticut. Recently, this technique has also been applied to ruptured aneurysms, with excellent results. In properly selected patients, avoiding a large incision with a quicker return to home and a normal lifestyle can be a life-saver. This is especially true for older patients who take longer to recover from traditional open surgery.
Because aneurysms can develop and become large before causing any symptoms, it is important to look for them in people who are at the highest risk. Experts recommend that men who are 65 to 75 years old and have ever smoked more than 100 cigarettes in their lifetime should be checked for abdominal aortic aneurysms.
Your physician’s decision to repair will be based on the risk of the aneurysm rupturing, along with surgical or procedure risks, and risks associated with other pre-existing conditions. Smaller aneurysms that cause back or abdominal pain may also need treatment, especially for those that are enlarging rapidly. It is most important that these aneurysms are detected early, when repair is much safer.
Dr. Muhs is co-director, Yale-New Haven Hospital Endovascular Center, attending vascular surgeon, Yale-New Haven Hospital, and assistant professor of surgery and radiology, Yale School of Medicine.
Each year, approximately 200,000 people in the United States are diagnosed with abdominal aortic aneurysm (AAA), a condition in which the large vessel that supplies blood to the abdomen, legs and pelvis, swells to more than 50 percent of its normal size. An AAA weakens the walls of the blood vessel, leaving it vulnerable to bursting open or rupturing, and spilling massive amounts of blood into the abdominal cavity. Without treatment, 80 percent of those who have an abdominal aortic aneurysm die when the blood vessel ruptures. With surgery prior to a rupture, the death rate drops to less than 5 percent.
Having two options for repair ... is associated with improvement in overall survival after surgery.
Often called a "silent killer" because there are usually no obvious symptoms of the disease, an abdominal aortic aneurysm can develop in anyone, but it is most frequently seen in males over 60, and more common in smokers or former smokers than in those who never smoked.
Research published in the June 2008 issue of the Archives of Surgery suggests that having two options for repair of ruptured abdominal aneurysms, including an open surgery and a less invasive procedure, is associated with improvement in overall survival after surgery.
According to researchers at the Medical University of Vienna, Austria, most patients with ruptured abdominal aortic aneurysms undergo a procedure known as open graft replacement, in which the aorta is repaired through an open incision and the damaged segment of the aorta is replaced with a synthetic graft. Over the past four decades, the mortality rates following surgery have remained unchanged at about 40 to 50 percent.
Andreas Wibmer, MD, and his colleagues at the Medical University of Vienna conducted an analysis of 89 consecutive patients treated for abdominal aortic aneurysms between 1999 and 2006. From 1999 through 2003, 42 patients were treated with open graft replacement. In 2003, the university established a protocol during which some selected patients (16 patients or 34 percent) were instead treated with the less invasive procedure, endovascular abdominal aortic aneurysm repair. With this procedure a mesh stent is inserted through the artery and positioned within the aorta.
The researchers found that the overall death rates in the 90 days after surgery decreased following the introduction of the endovascular procedure, from 54.8 percent in the first period to 27.7 percent in the second period. Improved survival was most apparent in patients older than 75 years. However, the 90-day death rate also decreased for patients undergoing open graft reduction following the introduction of endovascular repair, from 54.8 percent to 29 percent.
"Our findings strongly indicate that the implementation of endovascular abdominal aortic aneurysm repair is able to reduce the overall mortality in patients with ruptured abdominal aortic aneurysm," the authors write. "By offering both treatment options, it was possible to improve the immediate and mid-term overall results by shifting high-risk patients from the open graft reduction to the endovascular abdominal aortic aneurysm repair group, thereby improving the results of open surgery."
"The issue of which subgroup of patients might benefit the most from this less-invasive technique still remains," they continue. In the study, older patients and those whose blood pressure remained relatively constant appeared to experience the largest improvements in survival with this treatment option.