Five-year results from the Study of Thoracic Aortic Type B Dissection Using Endoluminal Repair (STABLE I) study of...

We report the final 5-year results from the Study of Thoracic Aortic Type B Dissection Using Endoluminal Repair (STABLE I) study, a prospective, single-arm, multicenter study of the Zenith Dissection Endovascular System (William Cook Europe, Aps, Bjaeverskov, Denmark), a pathology-specific device comprising a proximal stent graft with barbs and a distal bare stainless steel stent for the treatment of patients with complicated type B aortic dissection.

The study prospectively enrolled 86 patients (mean age, 59 years; 73% male) at sites in the United States, Europe, and Australia from 2007 to 2012. Treatment occurred during the acute phase (≤14 days after symptom onset) in 55 patients and during the nonacute phase (>14 days; all treated ≤90 days) in 31 patients. Five-year clinical and imaging follow-up was available for 88.5% of eligible patients.

The 30-day all-cause mortality rate was 5.5% (3 of 55) for acute and 3.2% (1 of 31) for nonacute patients (P > .99). The 5-year freedom from all-cause mortality was 79.9% ± 6.2% for acute and 70.1% ± 8.4% for nonacute patients (log-rank test, P = .40). The 5-year freedom from dissection-related mortality (including deaths of indeterminate relatedness to dissection repair) was 83.9% ± 5.9% for acute and 90.1% ± 5.9% for nonacute patients (log-rank test, P = .55). Complete false lumen thrombosis in the thoracic aorta increased over time and was observed in 74.1% of acute and in 58.8% of nonacute patients at 5 years. From preprocedure through 5 years, there was an overall increase in true lumen diameter and a concomitant decrease in false lumen diameter in both acute and nonacute patients at the level of the largest diameter in both the thoracic and abdominal aortas. At 5 years, 65.5% of acute and 81.3% of nonacute patients exhibited a stable or shrinking transaortic diameter in the thoracic aorta, and 48.3% of acute and 76.5% of nonacute patients had a stable or shrinking transaortic diameter in the abdominal aorta. Freedom from secondary intervention at 5 years was 65.5% ± 7.5% for acute and 71.2% ± 9.0% for nonacute patients (log-rank test, P = .71).

Endovascular repair of complicated type B aortic dissection with a composite device design demonstrated low all-cause mortality at 30 days, as well as low dissection-related mortality throughout follow-up. Overall, the acute and nonacute cohorts appeared to respond similarly to treatment involving use of the stent-graft and bare metal stent, demonstrating similar clinical outcomes and favorable improvement in aortic remodeling in the thoracic and abdominal aortas.