Five-year results of the LEOPARD trial of commercially available endografts.

OBJECTIVE: The LEOPARD (Looking at EVAR Outcomes by Primary Analysis of Randomized Data) trial is a randomized controlled trial comparing the outcomes of endovascular aneurysm repair (EVAR) using commercially available devices in a real-world population. METHODS: A prospective, randomized, multi-center trial was performed to compare the anatomically fixated (AF) AFX/AFX2 endograft system (Endologix) with endografts with proximal fixation (PF) (Cook Medical Zenith Flex; Gore Excluder; and Medtronic Endurant II) in patients with infrarenal abdominal aortic aneurysms. The primary endpoint was freedom from aneurysm-related complications (ARCs), a composite endpoint consisting of perioperative death (≤30 days), aneurysm rupture, conversion to open surgical repair, postoperative endoleaks, endograft migration (≥10 mm), aneurysm enlargement (≥5 mm), endograft limb occlusion, and device- or aneurysm-related reintervention. RESULTS: The study population was 455 patients enrolled at 56 United States centers: 235 patients were treated with AF devices and 220 with PF devices. The primary endpoint supported noninferiority of the AF cohort at 1 year. The 5-year freedom from ARC Kaplan-Meier estimates were 63.8% for AF patients and 55.5% for PF patients (P = .10). Kaplan-Meier estimates for freedom from aneurysm-related mortality were 98.7% and 97.0% in the AF group and 99.5% and 98.5% in the PF group at 1 and 5 years. There was no difference in aneurysm-related mortality, all-cause mortality, rupture, secondary interventions, and type I and type III endoleak between the two cohorts. The type III endoleak rate at 5 years for the AFX cohort was 1.5% and 0.0% for the comparator cohort (P = .11). There was a lower type II endoleak rate in the AF group at 5 years (78.8% vs 68.4%; P = .037). There were zero open surgical conversions (0.0%) in the AF group and four (2.0%) in the PF group. CONCLUSIONS: The 5-year results from the LEOPARD study demonstrated that there was no clinically significant difference in overall aneurysm-related outcomes between patients randomized to the AFX endograft system or commercially available endografts with proximal fixation.

Clinical outcome of an extended proximal seal zone with the AFX endovascular aortic aneurysm system.

OBJECTIVE: Despite improvements in endograft technology, operator skill, and patient selection, endovascular aneurysm repair continues to be associated with device-related complications. A retrospective, observational study was undertaken to evaluate the clinical outcome and imaging findings of a unique device having externally-mounted, conformable graft material. METHODS: Infrarenal abdominal aortic aneurysms were treated with the Endologix, Inc AFX endovascular aortic aneurysm system (Irvine, Calif) endograft in 108 consecutive patients over a 25-month period at two U.S. clinical sites. Baseline characteristics and procedural outcomes were reviewed by independent monitors. Serial computed tomography (CT) imaging assessments were performed by an independent core laboratory. Aortic neck characteristics and graft apposition were analyzed from center line-reformatted CT data sets in 37 patients in an imaging cohort comprising subjects with high-resolution baseline and follow-up CT imaging for precise assessment of aortic neck characteristics. The mean follow-up was 11 ± 5 months overall, 9 ± 6 months in patients with core laboratory imaging, and 5 ± 2 months for patients in the imaging cohort. RESULTS: Among the 108 patients, 103 (95%) had intact aneurysms and five (4.6%) were treated for rupture; 80 (74%) were male and 28 (26%) were female. On average, 2.3 ± 0.7 endograft components were implanted per patient and no adjunctive proximal neck bare stents were used. There were no perioperative deaths in patients with intact aneurysms; two patients who presented with ruptured aortic aneurysms (40%) died. Major adverse events occurred within 30 days of implantation in two patients (1.9%) with intact aneurysms. Type II endoleaks were evident on completion angiography in 18 patients (16.7%). Core laboratory analysis of CT studies identified two patients with type Ia endoleaks (2.3%), two with type III endoleaks (2.3%), and five with type II endoleaks (5.7%). Aneurysm-related secondary procedures were required in five patients over the first year of follow-up (4.6%). No patient developed endograft limb occlusion or aneurysm rupture and there were no open surgical conversions. In the imaging cohort, 360° graft-to-aortic wall apposition was continuous over a length of 25 ± 17 mm and extended the seal zone an average of 5 mm beyond the end of the anatomic neck. Early sac regression was correlated with neck length (P = .019) and graft-to-aortic apposition surface area (P = .039). CONCLUSIONS: The real-world use of the AFX endograft was associated with a low rate of device-and procedure-related complications. The ability to achieve an extended seal zone beyond the anatomical neck might in part contribute to positive outcomes, including the low type Ia and type II endoleak rate. These findings suggest that the AFX device might offer some advantages over other currently marketed endografts, but confirmation awaits the availability of longer-term outcome data.