Treating thoracic aortic disease (TAD) is often complex and difficult, but because endovascular treatment options have become more widely used and less invasive, a scientific statement issued by the American Heart Association, said that a more comprehensive review of the current state of medical management, open therapy and endovascular treatments of TAD is needed.
"The purpose of this scientific statement is to present a contemporary review of the various pathological processes that affect the descending thoracic aorta: aneurysms, dissections, intramural hematomas (IMHs), penetrating atherosclerotic ulcers (PAUs) and aortic transections,” according to the statement published online June 7 in Circulation.
Previously, perioperative mortality rates for TAD were reported to be between 12 and 44 percent, but current literature shows a decline in these numbers and reports current TAD mortality rates as between 4 and 9 percent.
Less invasive approaches to treat TAD, such as stent grafting, would be beneficial for older patients or those with pulmonary disease who are unable to undergo conventional open repair, said Michael A. Coady, MD, chair of the AHA Council on Cardiovascular Surgery and Anesthesia and Peripheral Vascular Disease.
“For high-risk groups, stent grafting offers the potential for lower morbidity and mortality than open repair. The exact role and specific recommendations for stent grafting, however, remain to be defined,” said Coady.
While the authors said that aortic stent grafting use should be based on a predicated operative risk that is lower than conventional treatments, they said that “it is not clear whether the trend toward more aggressive endovascular management of thoracic aortic disease will influence prognosis.”
According to the statement, patients with marfan syndrome and connective tissue disorders must be carefully considered for the procedure because the disease process for these patients often involves the descending thoracic aorta. At present time stent grafting is not recommended for these patients.
Because the rate of stroke is high during stent grafting, the authors said that patient selection and avoiding the aortic arch during intervention can help minimize the risk.
In addition, the authors said the when developing management protocols for proper patient selection for surgery, “it is essential to study risk factors that may influence the natural history of the disease.” For example, suggesting a smaller aortic size for patients with a family history of connective tissue disorders could be an option that would make them a candidate for surgery.
While the authors said that stent grafting has shown low mortality rates, there is risk for complications--endoleaks, stent fractures and aortic-related deaths--during the procedure. To prevent these complications, the authors said that “stent-graft patients require serial surveillance CT scans and possible reintervention at a later date.”
Currently, the researchers said that until more data are available stent grafting should not be performed on younger patients who have no other contraindication for conventional open surgery.
"Although the experience is quite limited, these studies demonstrated that stent grafting is feasible and a safe alternative to open surgical repair, especially in high-risk patients,” the authors concluded. “Although endovascular stenting offers a minimally invasive method of treatment, its long-term durability is still largely unknown. Ongoing experience and national and international registries will continue to define precise roles for both surgical and endovascular therapy."