A randomised controlled trial (RCT) of open repair versus endovascular aneurysm repair (EVAR) for the treatment of abdominal aortic aneurysms (AAAs), as well as head-to-head trials for additional information on EVAR and complex repairs, are warranted. This was the main conclusion of Ross Milner (Chicago, USA) during a presentation he delivered as part of an ‘EVAR Developments’ session at the recent Critical Issues America (CIA) annual meeting (2–4 February, Miami, USA).
The professor of surgery and chief of the Section of Vascular Surgery at the University of Chicago Medicine in Chicago opened his talk with reference to a 2020 Journal of Vascular Surgery paper by Konstantinos Spanos (Hamburg, Germany) and colleagues titled ‘A new randomised controlled trial on abdominal aortic repair is needed’.
In response to this need, Milner highlighted that Medtronic has launched three trials—HERCULES, ADVANCE and SOCRATES—the latter being the main focus of Milner’s talk at the CIA meeting. He homed in first on HERCULES. The purpose of this multicentre, global, randomised controlled postmarket trial, he shared, is to compare endosuture aneurysm repair (ESAR) to standard EVAR in the treatment of AAAs with wide proximal necks, and will be the first comparative trial to do so. He noted an enrolment goal of 300 patients at 40 sites across Europe and the USA.
Milner then turned his attention to ADVANCE, which he said is the first EVAR head-to-head RCT looking at aneurysm sac regression outcomes between two devices. “The ADVANCE clinical study will progress the work of sac regression as a key early indicator of long-term outcomes,” he remarked. The study will “bring EVAR evidence into the current decade,” Milner added, and “empower physicians to make precise, evidence-based clinical decisions that improve patient outcomes.”
SOCRATES, meanwhile, will focus on treatment modalities for an especially complex group of AAA patients. Its purpose, Milner elaborated, is to compare the safety and performance of ESAR versus fenestrated EVAR (FEVAR) for the treatment of AAA patients with infrarenal aortic proximal neck lengths of 4–15mm and minimal proximal sealing zone lengths of 8mm.
“Hostile aortic necks can lead to a loss of proximal seal over time,” he said by way of background to the study, detailing that short necks are associated with increased risk of type Ia endoleak and secondary procedures. Milner noted that there are two treatment options available here: extending the sealing zone proximally or reinforcing the sealing zone. SOCRATES will compare the two.
The trial will be conducted at up to 40 sites in the USA and Europe, with Milner listing Austria, Belgium, France, Germany, Italy, The Netherlands, Spain and Switzerland as the European countries participating in the trial.
In terms of patient selection, Milner relayed that at least 204 patients are due to be randomised (1:1) and evaluated for non-inferiority. Patients will be treated by one of two methods: ESAR with Medtronic’s Endurant II/IIs with Heli-FX EndoAnchor implants, or FEVAR with either Cook’s Zenith fenestrated stent graft system or—in Europe only—Terumo’s fenestrated Anaconda equivalent.
“[SOCRATES] will be the first comparative trial of ESAR and FEVAR in the treatment of patients ineligible for standard EVAR due to challenging anatomical criteria but within the IFUs [instructions for use] of the two treatment modalities,” Milner summarised. He added that the trial is actively enrolling.
The latest update from the trial, Milner shared, is from August of last year, when the first US patient was treated in the study by co-principal investigator Brant W Ullery in Portland, USA.
“We need more evidence,” Milner said in his closing statement, looking at the field of AAA repair as a whole. Looking forward, he specified that an RCT of open repair as compared to EVAR—as well as FEVAR and branched EVAR (BEVAR)—is needed, and that head-to-head trials “will ideally provide additional safety and efficacy information for EVAR and complex repairs.”
