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.

Objective: Arteriovenous fistulas created for hemodialysis often fail to become usable and are frequently abandoned. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in increasing radiocephalic fistula use for hemodialysis and secondary patency. Methods: PATENCY-2 was a randomized, double-blind, placebo-controlled trial in patients on or approaching the need for hemodialysis undergoing radiocephalic arteriovenous fistula creation. Of 696 screened, 613 were randomized, and 603 were treated (vonapanitase n = 405, placebo n = 208). The study drug solution was applied topically to the artery and vein for 10 min immediately after fistula creation. The primary endpoints were fistula use for hemodialysis and secondary patency (fistula survival without abandonment). Other efficacy endpoints included unassisted fistula use for hemodialysis, primary unassisted patency, fistula maturation and unassisted maturation by ultrasound criteria, and fistula procedure rates. Results: The proportions of patients with fistula use for hemodialysis was similar between groups, 70% vonapanitase and 65% placebo, (p = 0.33). The Kaplan–Meier estimates of 12-month secondary patency were 78% (95% confidence interval [CI], 73–82) for vonapanitase and 76% (95% CI, 70–82) for placebo (p = 0.93). The proportions with unassisted fistula use for hemodialysis were 46% vonapanitase and 37% placebo (p = 0.054). The Kaplan–Meier estimates of 12-month primary unassisted patency were 50% (95% CI, 44–55) for vonapanitase and 43% (95% CI, 35–50) for placebo (p = 0.18). There were no differences in the proportion of patients with fistula maturation or in fistula procedure rates. Adverse events were similar between groups. Vonapanitase was not immunogenic. Conclusions: Vonapanitase treatment did not achieve clinical or statistical significance to meaningfully improve radiocephalic fistula surgical outcomes. Outcome in the placebo group were better than in historical controls. Vonapanitase was well-tolerated and safe. TRIAL REGISTRATION: clinicaltrials.gov: NCT02414841 (https://clinicaltrials.gov/ct2/show/NCT02414841)

This book identifies the 50 key scientific articles in the field of vascular and endovascular surgery. It provides a commentary to each carefully selected paper and explains why these papers are so important, thus providing every surgeon with the foundation stones of knowledge in this fast-moving area. There has been an exponential increase in the volume and quality of published research relating to vascular and endovascular surgery in recent decades. Among thousands of articles, a small fraction is truly game changing. Such studies form the foundations of vascular surgery today and the selection of papers within this book provide the 50 landmark papers every 21st-century vascular and endovascular surgeon needs to know. A valuable reference not only to the established surgeon, but also to vascular surgery residents and trainees, as well as to more experienced surgeons as they continue to learn new techniques and approaches and to improve their knowledge of vascular disorders and treatments. The papers provide an evidence-based resource for those surgeons preparing for professional exams and may inspire clinicians to produce new research. About the Editors Juan Carlos Jimenez MD, MBA Professor of Surgery Gonda (Goldschmied) Vascular Center David Geffen School of Medicine at UCLA Los Angeles, California Samuel Eric Wilson, MD Distinguished Professor of Surgery and Chair Emeritus University of California Irvine Irvine, California