A multi-institutional analysis has demonstrated fenestrated endovascular aneurysm repair (FEVAR) could be a “safer and more durable option” than chimney EVAR (ChEVAR) in elective juxtarenal abdominal aortic aneurysm (AAA) cases with suitable anatomy, offering potentially “greater generalisability to real-world practice.”
ChEVAR was associated with significantly higher rates of type I endoleak and reintervention than FEVAR in a study of juxtarenal AAA cases carried out at five geographically distinct institutions with high-volume centres, the 2025 Society for Clinical Vascular Surgery (SCVS) annual symposium (29 March–2 April, Austin, USA) heard. In addition, FEVAR patients demonstrated significant sac regression, while those undergoing ChEVAR showed “a concerning trend” of early sac regression followed by late re-expansion. The study data were delivered by Clayton Brinster (UChicago Medicine, Chicago, USA).
Each centre enrolled at least 25 consecutive cases of FEVAR and/or ChEVAR, Brinster explained. Some 130 cases were analysed in total: 77 FEVAR and 53 ChEVAR. Significantly more patients in the ChEVAR group had persistent type I endoleak at one year—15 of the 53 patients, or 28%— vs. 6/77, or 7.8%, following FEVAR. Ten reinterventions were required in 8 of 77 (10.4%) FEVAR patients vs. 20 reinterventions in 16 of 53 (30.2%) ChEVAR patients. Significant sac regression was seen at 12 months (55mm, -7mm) and 24 months (51mm, -11mm) following FEVAR, Brinster told SCVS 2025. Sac regression was not significant at 12 months (59mm, -5mm) following ChEVAR, and sac re-expansion was observed in this group between 12 and 24 months (59 to 63mm, +4mm), he added.
Speaking to Vascular News ahead of the meeting, Brinster said the multi-institutional consortium behind the data was started four years ago and sought to elucidate granular institutional data on two widely used techniques.
“Although FEVAR and ChEVAR have both been around now for over a decade, there is a lack of granular institutional data,” he explained. “There have been maybe five or six solo institutional studies that incorporate some degree of parallel stenting versus FEVAR, but most include a comparison to open surgery or branched devices, or PMEGs [physician-modified endografts], so the data are not so clean. Besides that, it’s really just registry data with short-term follow-up.”
Brinster said the consortium’s strength is not only rooted in the fact it is regionally diverse, but it has also produced “granular institutional data.” The medical centres involved include the University of Chicago, Ochsner Health (New Orleans, USA), NYU Langone Medical Center (New York, USA), the Mayo Clinic (Scottsdale, USA), and the University of Rochester (Rochester, USA). “The data is therefore perhaps more generalisable to other institutions,” he continued. “It offers that advantage when compared to either national registry data or the US Aortic Research Consortium, because those are very sophisticated surgeons at the very best centers with the very best imaging, with carefully selected patients in general.”
Brinster said that some may argue the fact there were more endoleaks and reinterventions with ChEVAR was “a foregone conclusion,” but noted that there are many surgeons in the field who are experienced with parallel grafting and produce good results. In effect, the study aimed to answer—“for once and for all”—which of the two techniques is better.
“With fenestrated grafting, there are anatomic constraints, and many patients fall outside the IFU [instructions for use],” he said. “ChEVAR has both the advantage of possibly being able to treat those patients and the disadvantage that inherently those patients are more anatomically complex and more prone, perhaps, to gutter leak, endoleak and reintervention.”
Looking into sac behavior, Brinster pointed out the “unexpected” finding of FEVAR inducing sac regression. In the early stage, he said, ChEVAR induced sac regression, “but when we looked out to two years, there was a statistically significant increase in sac size, and that is particularly concerning.”
“I wanted to look into this because it has become an increasingly hot topic in our field,” he added. “It has been linked to late rupture, late intervention and late mortality after EVAR. There are some data out there looking at those outcomes for standard EVAR, but they only go out to one year in those studies—and it is registry data. There are two industry-sponsored registries looking at sac behavior after EVAR at one, three and five years, and that was the basis whereby now Medtronic can firmly recommend endoanchors, or ESAR [endosuture aneurysm repair], in certain anatomic circumstances to improve late outcomes by inducing sac regression. The main pinnacle there was that even stable sac size over time was linked to late poor outcomes.”
