Novel TEVAR System for Complicated Aortic Dissection Shows Promise

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Patients with acute, complicated type B aortic dissections can safely benefit from thoracic endovascular aortic repair (TEVAR) with a novel stent graft, according to a study presented January 27, 2014, at the Society of Thoracic Surgeons (STS) Annual Meeting in Orlando, FL.

Based in part on these results, the Valiant Captivia thoracic stent graft system (Medtronic, Minneapolis, MN) received an expanded indication to treat such dissections from the US Food and Drug Administration (FDA) January 22, 2014. The stent graft/delivery system was previously approved to treat vessel damage caused by disease or trauma (isolated lesions), excluding dissections. 

Joseph E. Bavaria, MD, of the University of Pennsylvania (Philadelphia, PA), and colleagues enrolled 50 patients with acute, complicated type B aortic dissection with malperfusion and/or rupture at 16 US institutions. Each patient was treated with the Valiant device at a median of 1.5 days after presentation with a planned follow-up out to 5 years.

Low Mortality, Adverse Events

Procedural success was 100% with a median procedural time of 142.9 minutes and a 14-day hospital length of stay. There were no conversions to open repair; 4 patients underwent secondary endovascular procedures within 1 year.

Mortality was 8.0% (n = 4) at 30 days and 14.0% (n = 7) from 31 days through 1 year. There were no instances of stent graft kinking, fracture, or loss of integrity at 1 year, although there was 1 case (3.0%) of undetermined type endoleak.

Within 30 days, serious adverse events included cardiac tamponade (n = 1), cerebral ischemia (n = 1), stroke (n = 3), paraplegia (n = 2), spinal cord ischemia (n = 1), and aortic dissection (retrograde type A; n = 1). Aortic dissection (n = 1) was the only 1 of these complications to occur after 30 days. There were no ruptures reported within 1 year.

At 1 year, the true lumen diameter remained stable or increased in 93.1% of patients, while the false lumen diameter remained stable or decreased in 75.9%. About three-quarters (71.4%) of patients had dissection extending to or past aortic bifurcation, and partial or complete false lumen thrombosis was seen in the stented segment in 90.9% of patients at 1 year.

Favorable remodeling was seen in the majority of patients within 1 year (table 1).

Table 1. Lumen Volume Remodeling

^aAt least 10% change from first postprocedural imaging.

 ‘Milestone’ Data

 In a telephone interview with TCTMD, Dr. Bavaria said the results show that “TEVAR for acute complicated type B dissections is very effective and very safe.”

The new FDA indication means physicians no longer have to rely on off-label technology, he added, although the procedure should only be performed by operators trained in the technique as the learning curve is “a bit more complicated.” TEVAR should also continue to be studied in other types of dissection as well, Dr. Bavaria noted.

“My crystal ball says that we’re going to be utilizing TEVAR for all forms of type B dissections more commonly in the future as we accumulate more data on the beneficial effects,” he said, adding that more studies are sure to follow, especially those associated with both the STS and the Society for Vascular Surgery (SVS). “I think that this is a very important milestone in the application of TEVAR to acute aortic conditions that are usually life threatening.”

Caution RegardingWider Use

Philip P. Goodney, MD, MS, of Dartmouth-Hitchcock Medical Center (Lebanon, NH), told TCTMD in an e-mail communication that “the current trends in the management of complex thoracic dissection continue to evolve.” However, he added, “some complications (such as retrograde arch dissection) still remain problematic, even in expert hands.”

The remaining issues include “dissemination of this technology, as well as a randomized comparison to medical treatment,” he commented. “While the experienced centers in this study were able to achieve good results, many express caution towards wider use outside of centers of excellence. [Also], determining which patients necessitate intervention, and which can be managed conservatively, remains a topic of interest and controversy.”

Study Details

The average age of patients was 57.2 years and four-fifths were male.

An average of 1.4 devices were implanted to treat a mean dissection length at baseline of 196.9 ± 67.1 mm. The proximal entry tear was covered in all patients, with no misaligned deployment.

Source:

Bavaria JE. Outcomes of TEVAR in acute, complicated type B aortic dissection: Results from the Valiant US-IDE study. Presented at: Society of Thoracic Surgeons Annual Meeting. January 27, 2014.

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