Vascular Surgeons Study Aortic Aneurysm Treatment Options
An abdominal aortic aneurysm is an abnormal expansion of the aorta that typically develops slowly and without symptoms, causing weakness in the vessel wall and bulging of the aorta itself, and increasing the risk for rupture. When such aneurysms are smaller than 5 centimeters in diameter, the risks associated with open surgical repair are often considered greater than the risk of closely monitoring the aneurysm. Surgical repair typically has been recommended once an aneurysm reaches 5 to 6 centimeters, when the risk of rupture is considered higher than the risks associated with surgery.
With the availability of minimally invasive techniques to repair the defect, however, researchers hope to determine whether a new standard of care is in order for smaller aneurysms.
"We suspect that the ability to repair these aneurysms with a minimally invasive surgical procedure means we could safely repair them soon after they're diagnosed," said Dr. Jean Starr, a vascular surgeon and principal investigator for Ohio State University Medical Center's participation in the trial. "But we need evidence to know for sure."
Up to 2 million Americans have abdominal aortic aneurysms (AAAs), but because most patients have no symptoms, only about 200,000 cases are diagnosed each year. An estimated 15,000 people die each year from undiagnosed AAAs that rupture, causing massive internal bleeding. People considered at highest risk for the condition are smokers; those with high blood pressure, high cholesterol, obesity, emphysema or family history; and men older than 60 with one or more other risk factors.
In the study, patients will be randomized to receive either early endovascular placement of a stent graft in the aorta or medical surveillance of the abdominal aortic aneurysm. A federally approved device, called an AneuRx AAA Stent Graft, will be placed in patients randomized to receive the intervention. In the minimally invasive procedure, surgeons enter the femoral artery through an incision in the leg, inserting a catheter to position the woven polyester graft tube inside the aorta. When the stent graft is placed, it provides a permanent, alternative channel for blood flow and circumvents the aneurysm.
Patients under close surveillance whose aneurysms grow larger than 5 centimeters in diameter during the course of the study will receive intervention as well.
Vascular surgeons at 50 centers nationally will enroll nearly 1,700 patients in the trial. Starr and colleagues expect to enroll 35 patients at Ohio State. Overall, researchers seek to determine when in the development of an abdominal aortic aneurysm is the optimal time to intervene with endovascular repair. In addition, researchers will compile data on aneurysm-related problems in smokers vs. nonsmokers, aneurysm ruptures, duration of hospital stay, procedure duration and other patient outcomes related to the use of the stent graft.