Researchers have reported comparable five-year outcomes of the Gore Excluder iliac branch endoprosthesis (IBE; Gore) in both the investigational device exemption (IDE) and GREAT registry studies of the device.
Meghan Barber, MD, a vascular surgery fellow at the University of Chicago, shared this main finding from a new comparative study at the 49th annual meeting of the Midwestern Vascular Surgical Society (MVSS) in Cincinnati, Ohio (Sept. 18–20).
Barber began by sharing the researchers’ hypothesis that there would be no difference in outcomes between the IDE study of the IBE device and the IBE component of the GREAT registry, representing “ideal” and “real-world” scenarios, respectively.
In order to test their hypothesis, the researchers compared the five-year outcomes of patients included in both the IDE study and the GREAT registry in the period 2013–2016. “We looked at all-cause mortality, aortic-related mortality, aortic rupture, reintervention, fracture, migration, endoleak and aneurysm growth,” Barber tells Vascular Specialist, reporting that the only differences identified between the two groups were that more patients were followed out to five years in the GREAT registry and that there was “slightly higher” all-cause mortality in GREAT. “Otherwise,” she says, “there was no difference between the two sets of patients.”
Barber comments that these results are “really good” for the IBE device. She notes: “The good outcomes we were able to demonstrate in the controlled setting of an IDE trial translated very well to the patients that were in the GREAT registry.”
Going into more detail about the two studies, senior author Ross Milner, MD, chief of vascular surgery at the University of Chicago, explains that the IBE component of GREAT comprises the final group of patients included in the registry. He explains: “When the IBE device got FDA [Food and Drug Administration] approval, it was actually fairly close to the time that we had enrolled the 5,000 patients we were looking for, so we actually have more patients in the registry than the IDE study.” Milner goes on to note that there were roughly 60 patients included in the IDE study compared to around 90 in the IBE component of GREAT.
Considering the take-home message from the new data, Milner says that the ability to use an iliac branch device for internal iliac artery preservation was “equally effective” in both the IDE study and the GREAT registry. He adds that those who perform endovascular aneurysm repair (EVAR) with an IBE can be “confident” their outcomes will mimic those seen in the setting of a clinical trial.
From a strategy standpoint, Milner continues, “most people would prefer to use an internal iliac branch when possible, for preservation.” He does stress, however, that both the IDE study and IBE portion of GREAT are U.S. centric, which “obviously makes it a little bit harder to extrapolate to the rest of the world.”
On the next steps for GREAT, Milner notes that there are now long-term follow-up data available, referencing 10-year results on some of the patients treated with standard EVAR using the Excluder abdominal aortic aneurysm (AAA) endoprosthesis (Gore). “That’s the predominant patient population in the registry,” he says, noting that almost 3,300 patients out of 5,000 in GREAT underwent EVAR with the Excluder.
Milner notes that one of the limitations of GREAT, however, is the lack of core-lab imaging. “We’re completely dependent on the sites for recognition of problems,” he says. In order to address this, Milner explains that Gore has now established the TOGETHER registry, which will feature core-lab imaging and a “more in-depth understanding of patient selection.”
“The goal is to collect 150 IBE patients,” Milner shares, highlighting the main goal of TOGETHER as being to assess branch technology, with the Gore IBE set to be a “big component” of the study.
The pair also consider the Gore IBE as part of the wider treatment landscape. While acknowledging that changes in how patients are treated are inevitable, Barber emphasizes that the IBE is “still a fairly unique device.” She remarks: “I don’t think that much has changed in the last five years at least, but in the next 10 years that may be a different story.”
