When patients with favorable neck anatomy undergo endovascular aneurysm repair (EVAR) instead of open surgical repair (OSR) for abdominal aortic aneurysm (AAA), sac behavior appears to be heavily influenced by treatment decisions related to antithrombotic therapy.
Researchers explored this topic for a new analysis published in the Journal of Vascular and Interventional Radiology.
"EVAR is a less invasive treatment for AAA compared with OSR," wrote lead author Koichi Morisaki, MD, PhD, a specialist at Kyushu University in Japan, and colleagues. "Although EVAR has shown early benefits, its long-term benefits remain controversial because of the need for more frequent re-interventions after EVAR."
The team analyzed data from more 182 patients with favorable neck anatomy who underwent EVAR for AAA from 2007 to 2019. All patients were treated at the same facility.
Overall, the authors determined that occluded inferior mesenteric artery (IMA), the presence of posterior thrombus and no antiplatelet therapy were all associated with AAA sac shrinkage after one year.
Persistent type II endoleaks were seen in 30.8% of patients—patent inferior mesenteric artery, a lack of posterior thrombus, the number of patent lumbar arteries and antiplatelet therapy were all confirmed to be "significant risk factors" of such a complication.
While the rate of persistent type II endoleaks was 39.2% for patients on antiplatelet therapy, that rate was 24.3% in patients not undergoing antiplatelet therapy. The rates among patients receiving and not receiving anticoagulation therapy, meanwhile, were 50.0% and 28.9%, respectively.
Also, initial AAA diameter, a lack of posterior thrombus, antiplatelet therapy and anticoagulation therapies were all identified as risk factors for late AAA sac regression.
"Sac shrinkage has been reported to be a good surrogate marker of treatment outcomes after EVAR,” the authors wrote. "In line with such findings, this study found that patients with sac shrinkage one year after EVAR remained free from late aneurysm sac expansion. Moreover, the present study showed that antiplatelet therapy, the absence of a posterior thrombus, and patent IMA were independent risk factors for lack of sac regression one year after EVAR. Among the aforementioned risk factors, patent IMA can be addressed through pre-emptive IMA embolization as the efficacy of IMA embolization before EVAR has been proved by a prospective randomized controlled trial."
Read the full study here.
Some of this work was presented at the Annual Meeting of the Japanese College of Angiology in October.