NEW YORK (Reuters Health) – Thoracic endovascular aortic repair (TEVAR) improves aortic remodeling in patients with stable dissection of the descending aorta, but it remains unclear whether long-term outcomes are improved, say the INSTEAD trial researchers in the December 22/29 issue of Circulation.

When stable and uncomplicated, a dissection in the descending aorta (known as a type B dissection) can be managed “with strict medical treatment and surveillance,” lead author Dr. Christoph A. Nienaber from University of Rostock, Germany told Reuters Health. But, he added, conservative management requires “frequent visits and imaging to pick up enlargement and late evidence of complications that require fixing with stent-grafts.”

Dr. Nienaber and colleagues investigated the impact of endovascular stent grafts as an adjunct to medical treatment and surveillance in 140 patients with type B dissection considered uncomplicated at the time of trial inclusion.

The probability of all-cause survival at 2 years did not differ significantly between the patients managed with TEVAR (88.9%) or medical treatment (95.6%), the authors report.

Similarly, there was no significant difference in the probability of freedom from aorta-related death (94.4% for TEVAR and 97.0% for medical treatment alone, P=0.44).

The combined end point of aorta-related death, crossover/conversion for expansion, and ancillary procedures did not differ between the treatment groups.

Placement of a stent graft was followed by significant expansion of the thoracic true lumen at 3 months and 2 years, the researchers note, whereas the maximal false-lumen diameter shrank at both of these time points.

In contrast, medical treatment alone failed to demonstrate significant true-lumen recovery or false-lumen shrinkage.

TEVAR enhanced the process of false-lumen thrombosis, but false-lumen thrombus formation occurred in only a minority of patients managed medically.

In an editorial, Dr. Christopher J. Kwolek and Dr. Michael T. Watkins, from Harvard Medical School, Boston write, “These findings underscore the potential ability of TEVAR to modulate late death related to type B dissection by creating favorable aortic remodeling.”

Dr. Nienaber added, “Our international cohort…will be followed up over 5 years hoping to identify prognosticating factors and identifying late differences between treatment groups.”

Reference:
Circulation 2009;120:2513-2514,2519-2528.