CHICAGO – The need for additional intervention after repair of the ascending aorta in extended type A aortic dissection has been thought to follow the practice for type B dissection and favor preemptive thoracic endovascular aortic repair. However, preemptive TEVAR may, at least in the midterm, provide no benefit in patients with extended type A dissections, according to results reported at the annual meeting of the Midwestern Vascular Surgery Society.
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“TEVAR does not appear to be indicated in patients with extended type A dissections after acute aortic repair,” said Amy B. Reed, MD, of the University of Minnesota.
The study’s hypothesis was that growth rates of dissection and the need for additional intervention in the descending thoracic aorta are similar between extended type A (ExTA) and type B aortic dissection after initial repair of the ascending aorta. Dr. Reed noted that investigators from the INSTEAD-XL trial reported that preemptive TEVAR improved outcomes in patients with type B dissections (Circ Cardiovasc Interv. 2013;6:407-16). “The thinking has been that patients with uncomplicated ExTA would also benefit from early TEVAR,” Dr. Reed said.
The study evaluated 87 consecutive patients from 2011 to 2018, 43 with ExTA and 44 with type B dissections. Characteristics of both groups were similar, except the type B group had a significantly higher rate of coronary artery disease, 16% vs. 0% (P = .01). The distal extent of the dissection was beyond the aortic bifurcation in 75% of the ExTA patients and 52% of the type B group, “so we felt that these groups were really well matched,” Dr. Reed said.
Of the 43 ExTA patients, five had repair and 38 had no intervention. At an average follow-up of 33 months, 23 of the no-intervention patients showed no growth of their dissection, Dr. Reed said. In the type B group, 15 had no repair, and of those nine showed no growth (one patient died early and five did show growth).
“When we look at intervention-free survival, there’s a significant difference between our ExTA patients vs. our type B patients over time, with significantly more type B patients requiring intervention,” she said. At 28 months, 88% of ExTA were intervention free, whereas at 9 months 35% of type B patients were.
“We feel that, following the repair of ascending acute aortic dissection, in those patients with ExTA dissections, there does appear to be a slow progression of distal aortic disease,” Dr. Reed said. “Rarely do these patients develop complications such as dissection needing intervention either in the acute hospital period or delayed.”
Because the findings are based on medium-term follow-up, she said, “We certainly need further follow-up to confirm these midterm findings.”
Dr. Reed had no relevant financial relationships to disclose.