Five-year results of the STABLE II study for the endovascular treatment of complicated, acute type B aortic dissection with a composite device design.

OBJECTIVE: To provide the 5-year outcomes of the use of a composite device (proximal covered stent graft + distal bare stent) for endovascular repair of patients with acute, type B aortic dissection complicated by aortic rupture and/or malperfusion. METHODS: Study of Thoracic Aortic Type B Dissection Using Endoluminal Repair (STABLE) II was a prospective, multicenter study of the Zenith Dissection Endovascular System (William Cook Europe). Patients were enrolled between August 2012 and January 2015 at sites in the United States and Japan. Five-year follow-up was completed by January 2020. RESULTS: In total, 73 patients (mean age: 60.7 ± 10.9 years; 65.8% male) with acute type B dissection complicated by malperfusion (72.6%), rupture (21.9%), or both (5.5%) were enrolled. Patients were treated with either a composite device (79.5%) or the proximal stent graft alone (no distal bare stent, 20.5%). Dissections were more extensive in patients who received the composite device (408.9 ± 121.3 mm) than in patients who did not receive a bare stent (315.9 ± 100.1 mm). The mean follow-up was 1209.4 ± 754.6 days. Freedom from all-cause mortality was 80.3% ± 4.7% at 1 year and 68.9% ± 7.3% at 5 years. Freedom from dissection-related mortality remained at 97.1% ± 2.1% from 1-year through 5-year follow-up. Within the stent-graft region, the rate of either complete thrombosis or elimination of the false lumen increased over time (82.1% of all patients at 5 years vs 55.7% at first postprocedure computed tomography), with a higher rate at 5 years in patients who received the composite device (90.5%) compared with patients without the bare stent (57.1%). Throughout the follow-up, overall true lumen diameter increased within the stent-graft region, and overall false lumen diameter decreased. At 5 years, 20.7% of patients experienced a decrease in maximum transaortic diameter within the stent-graft region, 17.2% experienced an increase, and 62.1% experienced no change. Distal to the treated segment (but within the dissected aorta), 23.1% of patients experience no change in transaortic diameter at 5 years; a bare stent was deployed in all these patients at the procedure. Five-year freedom from all secondary intervention was 70.7% ± 7.2%. CONCLUSIONS: These 5-year outcomes indicate a low rate of dissection-related mortality for the Zenith Dissection Endovascular System in the treatment of patients with acute, complicated type B aortic dissection. Further, these data suggest a positive influence of composite device use on false lumen thrombosis. Continuous monitoring for distal aortic growth is necessary in all patients.

Results of the United States multicenter prospective study evaluating the Zenith fenestrated endovascular graft for treatment of juxtarenal abdominal aortic aneurysms.

OBJECTIVE: This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the Zenith fenestrated endovascular graft (Cook Medical, Bloomington, Ind) for treatment of juxtarenal abdominal aortic aneurysms (AAAs). METHODS: Sixty-seven patients with juxtarenal AAAs were prospectively enrolled in 14 centers in the United States from 2005 to 2012. Custom-made fenestrated stent grafts were designed with one to three fenestrations on the basis of analysis of computed tomography data sets. Renal alignment was performed with balloon-expandable stents. Follow-up included clinical examination, laboratory studies, mesenteric-renal duplex ultrasound, abdominal radiography, and computed tomography imaging at hospital discharge and at 1 month, 6 months, and 12 months and yearly thereafter up to 5 years. RESULTS: There were 54 male and 13 female patients with a mean age of 74 ± 8 years enrolled. Mean aneurysm diameter was 60 ± 10 mm. A total of 178 visceral arteries required incorporation with small fenestrations in 118, scallops in 51, and large fenestrations in nine. Of these, all 118 small fenestrations (100%), eight of the scallops (16%), and one of the large fenestrations (11%) were aligned by stents. Technical success was 100%. There was one postoperative death within 30 days (1.5%). Mean length of hospital stay was 3.3 ± 2.1 days. No aneurysm ruptures or conversions were noted during a mean follow-up of 37 ± 17 months (range, 3-65 months). Two patients (3%) had migration ≥ 10 mm with no endoleak, both due to cranial progression of aortic disease. Of a total of 129 renal arteries targeted by a fenestration, there were four (3%) renal artery occlusions and 12 (9%) stenoses. Fifteen patients (22%) required secondary interventions for renal artery stenosis/occlusion in 11 patients, type II endoleak in three patients, and type I endoleak in one patient. At 5 years, patient survival was 91% ± 4%, and freedom from major adverse events was 79% ± 6%; primary and secondary patency of targeted renal arteries was 81% ± 5% and 97% ± 2%, freedom from renal function deterioration was 91% ± 5%, and freedom from secondary interventions was 63% ± 9%. CONCLUSIONS: This prospective study demonstrates that endovascular repair of juxtarenal AAAs with the Zenith fenestrated AAA stent graft is safe and effective. Mortality and morbidity are low in properly selected patients treated in centers with experience in these procedures.

Prospective multicenter clinical trial (STABLE) on the endovascular treatment of complicated type B aortic dissection using a composite device design.

OBJECTIVE: This study evaluates the safety and effectiveness of a unique composite thoracic endovascular aneurysm repair (TEVAR) construct (proximal stent graft and distal bare metal stent) for the treatment of patients with complicated type B aortic dissection (cTBAD). METHODS: In this prospective, single-arm, multicenter study, patients with cTBAD were treated with an endovascular system consisting of proximal TX2 thoracic stent grafts and distal bare metal dissection stents (Zenith Dissection Endovascular System; Cook Medical, Bloomington, Ind). Indications for enrollment were branch vessel malperfusion, impending rupture, aortic diameter ≥40 mm, rapid aortic expansion, and persistent pain or hypertension despite maximum medical therapy. One-year follow-up results, including clinical and radiographic (computerized tomography [CT] and X-ray) evaluation, were available for this report. RESULTS: Ten centers enrolled 40 patients (70% men; mean age 58 years old) between December 2007 and August 2009. The onset of symptoms was acute (≤14 days) in 24 patients (60%), subacute (15-30 days) in six patients (15%), and chronic (31-90 days) in 10 patients (25%); the overall mean time from symptom onset to treatment was 20 days (range, 0-78 days). A majority of patients (77.5%; 31 of 40 patients) presented with impending aortic rupture (indicated by periaortic effusion/hematoma) or branch vessel malperfusion. Seven combinations of stent grafts and dissection stents were used, and all devices were successfully deployed and patent. The 30-day mortality rate was 5% (2 of 40); two deaths occurred after 30 days, leading to a 1-year survival rate of 90%. Two deaths, occurring at 11 and 81 days postprocedure, respectively, were secondary to aortic rupture. Morbidity occurring within 30 days included stroke (7.5%), transient ischemic attack (2.5%), paraplegia (2.5%), retrograde progression of dissection (5%), and renal failure (12.5%). Additional morbidity after 30 days included one case of retrograde progression of dissection and one case of renal failure. None of the patients with renal failure became dialysis-dependent. Four patients (10%) underwent secondary interventions within 1 year. Favorable aortic remodeling was observed during the course of follow-up, indicated by an increase in the true lumen size and a concomitant decrease in the false lumen size along the dissected aorta, with completely thrombosed thoracic false lumen observed in 31% of patients at 12 months as compared to 0% at baseline. CONCLUSIONS: Initial data with a composite TEVAR construct have demonstrated favorable clinical and anatomic results. Continued enrollment and long-term data are needed to assess the overall effectiveness of this treatment strategy.

Intermediate results of a United States multicenter trial of fenestrated endograft repair for juxtarenal abdominal aortic aneurysms.

OBJECTIVE: This article reports the intermediate-term (24-month) outcomes of a prospective multicenter trial designed to evaluate the Zenith Fenestrated AAA Endovascular Graft (Cook Medical, Bloomington, Ind) for treating juxtarenal abdominal aortic aneurysms with short proximal necks. The study goals were to evaluate the safety and preliminary effectiveness of the device and refine patient selection criteria. METHODS: Five centers in the United States enrolled 30 patients with juxtarenal aortic aneurysms with >or=50-mm diameter and short proximal necks. Devices were custom-designed for each patient based on measurements from reconstructed computed tomography (CT) data. Follow-up studies included physical examinations, laboratory studies, CT imaging, mesenteric-renal duplex ultrasound imaging, and abdominal flat plate radiographs at hospital discharge, at 1, 6, and 12 months, and yearly thereafter up to 5 years. RESULTS: During a 1-year period, 30 patients (80% men; mean age, 75 years) with a mean aneurysm size of 61.4 mm were enrolled. In these 30 patients, 77 visceral vessels were accommodated by fenestrations located within the sealing segment of the grafts. The most common design accommodated two renal arteries and the superior mesenteric artery (66.7%). All prostheses were implanted successfully. No visceral arteries were lost. Of the 30 patients treated, 27 were available for 12-month follow-up and 23 were available for 24-month follow-up. No aneurysm-related deaths, aneurysm ruptures, or conversions were observed through 24 months of follow-up. No type I or type III endoleaks were observed. Type II endoleaks were noted in six (26.1%) at 12 months and four (20.0%) at 24 months. No patients had aneurysm growth >5 mm. Aneurysm size decreased in 16 of 23 (69.6%) and was stable in the remaining patients at 24 months. Eight patients experienced a renal event (4 renal artery stenoses, 2 renal artery occlusions, and 2 renal infarcts). Five underwent secondary interventions. No renal failure developed requiring dialysis. CONCLUSIONS: The intermediate-term (24-month) results of the 30 patients in this multicenter study are concordant with previous single-center studies and support the concept that placement of fenestrated endovascular grafts is safe and effective at centers with experience in endovascular repair and renal/mesenteric stent placement.