March 25, 2020
STABLE II Data Published for Cook’s Zenith Dissection Endovascular System to Treat Acute, Complicated Type B Aortic Dissections
March 25, 2020—Findings from the STABLE II clinical trial of the Zenith dissection endovascular system (Cook Medical) were published by Global Principal Investigator Joseph V. Lombardi, MD, et al in the Journal of Vascular Surgery (JVS; 2020;71:1077–1087.e2). The trial evaluated the safety and effectiveness of the Zenith dissection system’s composite device design (covered stent graft and bare-metal stent) for the treatment of patients with acute, complicated type B aortic dissection (TBAD) presenting with aortic rupture and/or branch vessel malperfusion.
The investigators reported the primary outcomes at 30 days and follow-up results through 1 year, reflecting study data as of March 2018. They concluded that the 30-day and 1-year results from the STABLE II study demonstrated favorable clinical and anatomic outcomes for the treatment of rupture and malperfusion in the setting of acute, complicated TBAD. The investigators advised that 5-year follow-up is ongoing.
As summarized in JVS, the prospective, nonrandomized, multicenter STABLE II study was composed of 73 patients (65.8% male; mean age, 60.7 years) with acute, complicated TBAD who were enrolled between August 2012 and January 2015 to receive treatment with the Zenith dissection endovascular system at institutions in the United States and Japan. The primary safety endpoint was the rate of freedom from major adverse events at 30 days, and the primary effectiveness endpoint was the rate of survival at 30 days.
Of the 73 patients, 20 presented with aortic rupture (27%) and 57 presented with branch vessel obstruction/compromise (78%), including four patients presenting with both conditions. The covered stent graft was used in all patients (median, 1; range, 1–3; one stent graft used in 64.4%; 47/73), and the bare-metal dissection stent was used in 58 of 73 patients (79.5%).
The investigators reported the following:
- Thirty-day mortality occurred in five patients (6.8%): one procedure-related death, three unrelated to dissection repair, and one indeterminate.
- Thirty-day major adverse events included myocardial infarction (1.4%), bowel ischemia (1.4%), renal insufficiency/renal failure requiring dialysis (6.8%), stroke (6.8%), paraplegia or paraparesis (5.5%), and prolonged ventilatory support (13.7%).
- From 31 to 365 days, there were nine deaths (with one related to dissection repair) with a Kaplan-Meier estimate of freedom from all-cause mortality of 80.3% ± 4.7% at 1 year.
- Within 365 days, nine of 73 patients (12.3%) underwent 10 secondary interventions; no patients required conversion to open surgery.
- At the 12-month follow-up, complete or partial thrombosis of the false lumen was seen in 100% of patients (46/46) within the stent graft region and in 97.4% of patients (38/39) within the dissection stent region.
- At 12 months, growth (> 5 mm) of the maximum transaortic diameter was observed in 14.9% of patients (7/47) in the stent graft region and in 38.5% of patients (15/39) within the dissection stent region.
As noted in JVS, the STABLE II data were first presented at the 2016 annual meeting of the Society for Vascular Surgery held June 8–11 in National Harbor, Maryland. The Zenith dissection endovascular system was approved by the FDA and launched by Cook Medical in early 2019.