Endovascular aortic repair (EVAR) is safe, durable and effective, the five-year interim results of the Global Registry for Endovascular Aortic Treatment (the GREAT registry) show.
In this analysis of more than 3,000 abdominal aortic aneurysm (AAA) patients treated with an abdominal aortic stent graft, Ross Milner, a professor of surgery at the University of Chicago, told attendees of the 2021 Charing Cross Symposium (CX), held April 19–22 online, that the investigators saw excellent technical success, procedural survival, and hospital survival rates, as well as no stent fractures, negligible occurrence of stent compression and/or migration, and low aortic- and device-related reintervention rates. In addition, there were extremely low aortic-related mortality and post-EVAR aortic rupture rates, with approximately 88% sac regression or stability at five years.
Endovascular aortic repair (EVAR) is the most common means for abdominal aortic aneurysm (AAA) repair—“clearly, there is a benefit in early survival, perioperative morbidity, and decreased length of stay compared to open repair,” Milner said in his introduction to the topic. When looking at the mid- to long-term results, though, he noted that the survival curves merge, but added that EVAR patients exhibit a significantly elevated reintervention rate at extended follow-up time points.
“Questions remain about the long-term durability and efficacy of EVAR,” he continued. “The paucity of long-term outcomes in real-world use of EVAR has created space for quality EVAR registry data to help answer these questions.”
Enter the GREAT registry. This looked at five-year outcomes of the Gore Excluder graft in “real-world” use, with a focus on safety, durability and efficacy. The primary endpoints were the presence of any endoleaks, stent fracture or migration, aortic rupture, and/or endograft explantation. Secondary endpoints included the serious device event rate, aortic-related mortality, ad long-term survival.
Over 3,200 patients were included in this worldwide registry, with just over half being from the U.S. Five-year data are available from 64% of the total cohort eligible for follow-up (306 of 477 individuals). In terms of the index procedural characteristics, Milner told the CX audience that “a little over 5% of patients had less than a 15mm neck indication, which was considered on-label for the excluder. Over 10% had either greater than 60° or 75° neck angulation, which is off-label for the excluder.
Procedural survival was 100%, and intensive care unit (ICU) stay was necessary in fewer than 3% of patients. Hospital survival was almost 100%.
Instructions for use (IFU) violations differ based on patients’ anatomic features, Milner explained, “but almost 60% of the cases did not follow the IFU. That is one of the unique characteristics of this registry.”
Freedom from aorta-related mortality through to five years was seen in 98.8% of patients. Overall survival at five years was 71.2%. “This is fairly good compared to some other studies,” the CX audience heard.
Detailing key outcomes at five years, Milner told listeners that the event rates were relatively low: “only 5% experienced device-related complications, fewer than 1% had a need for conversion of explantation, and there was only one stent graft migration, and two compressions. So very low rates of device-related complications,” he stressed, “and aortic rupture rate of 0.3%.” Freedom from aortic rupture through five years is therefore reported as 99.7%.
“The aneurysm sac behavior has been very positive: when you look at the five-year results (which is 201 patients available for follow-up), you have almost 88% sac regression or stability, with 64% having a regressing sac, and only 12% with an increasing sac, which is excellent aneurysm sac behavior,” Milner testified.
He did list some limitations of the study, notably that the follow-up is less than 80%. However, he said this “likely reflects the ‘real-world’ circumstances”.
During the same CX session, Dennis Gable, a vascular surgeon in Plano, Texas, and Santi Trimarchi, a vascular surgeon in Milan, Italy, also spoke, contextualizing the GREAT registry data.
After presenting on the outcomes of open versus percutaneous access for patients enrolled in the GREAT registry, Gable informed attendees that percutaneous only access for endovascular treatment of aortic pathologies can be performed safely for small and large sheath access. There was a significantly lower rate of vascular access complications when percutaneous only access methods were used compared with other techniques.
Furthermore, percutaneous methods were also associated with a significantly lower hospital length of stay in the EVAR group, with a trend toward a shorter length of stay in the TEVAR group. The speaker also noted that increased sheath size “does not appear to increase the risk of access site complication.” He added that this analysis demonstrates that percutaneous only access is safe, has low complication rates no different than traditional open surgical access, and has a shorter length of hospital stay compared with open access or combined access techniques.
Trimarchi spoke on the endovascular treatment of complicated versus uncomplicated acute type B aortic dissection generally. He concluded that in the GREAT registry, thoracic endovascular aortic repair results for complicated type B aortic dissections versus uncomplicated acute type B aortic dissections showed that 30-day mortality and perioperative complications were equally low for both. The midterm outcome was positive.
In terms of perspective, we may say that GREAT is a registry that is important because it supports endovascular repair as a first-line strategy for treating complicated type B dissections However, this is also important for uncomplicated dissections, because in the absence of level A evidence from a randomized controlled trial, results from a registry are of great importance to better understand the risks and benefits associated with endovascular aortic repair.”
