PONTE VEDRA BEACH, FLA. — Now that the first thoracic-aorta endograft is on the U.S. market, a revolution has begun in managing thoracic aorta aneurysms and dissections.
“This is a big deal. Dramatic changes are taking place in managing thoracic-aorta diseases,” Alan B. Lumsden, M.D., said at the annual meeting of the Society for Cardiovascular Angiography and Interventions.
On March 23, the Food and Drug Administration approved the Gore TAG endoprosthesis for repair of aneurysms in the descending thoracic aorta. Several additional endoprostheses are in development, and the types of patients who are candidates for receiving these devices are expanding.
Thoracic-aorta aneurysms appear to be less prevalent than abdominal-aorta aneurysms, but thoracic defects also are underdiagnosed. Current prevalence numbers are 10.4/100,000 people. The risk factors for both abdominal and thoracic aneurysms largely overlap. The incidence of thoracic aneurysms increases markedly as people age, and the incidence also seems to be increasing overall in the United States, said Dr. Lumsden, chief of the division of vascular surgery and endovascular therapy at Baylor College of Medicine in Houston.
Most patients with thoracic-aorta aneurysms are asymptomatic; the defects are picked up incidentally in chest x-rays and CT scans. The most common symptom is pain in the shoulders or back.
Like abdominal-aortic aneurysms, the risk of rupture in thoracic aneurysms rises with the size of the aneurysm. Surgical repairs usually have not been done until the aneurysm reached about 6 cm in diameter because of the high rate of surgical complications. In patients without Marfan's syndrome, an ascending thoracic aneurysm usually has been repaired when it reached 5.5 cm in diameter, and a descending thoracic aneurysm has been repaired when it reached 6.5 cm. In patients with Marfan's syndrome, the thresholds for repair have usually been scaled back by 0.5 cm.
Endovascular repair is already the treatment of choice for symptomatic patients and those with a risk of an impending rupture. But increasingly, more complicated aneurysm patients, as well as patients with uncomplicated aortic dissections, will be treated endovascularly.
Several recent reports have documented new types of surgical procedures that have “increased the landing zone” for endovascular stenting. “In the past, we were limited by the location of the celiac, subclavian, and carotid arteries, but now there are good ways to move those around,” he said.
A descending thoracic-aorta aneurysm is repaired with an endovascular stent. Courtesy Dr. Alan B. Lumsden