AUTHOR=Duan Yu , Xu Binbin , Qin Xuanfeng , Mao Renling , Hu Yuanyuan , Zhou Bin , Li Jian , Chen Gong 

TITLE=Flow diversion effect of the leo braided stent for aneurysms in the posterior and distal anterior circulations: A multicenter cohort study

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.957709

DOI=10.3389/fneur.2022.957709

ISSN=1664-2295

ABSTRACT=Abstract
Background and purpose: The treatment of aneurysms located in the posterior and distal anterior circulations is still challenging. Leo stent with flow diversion (FD) effect may be a one of a potential option, which need to be studied clearly. Methods: From January 2016 to October 2021, 133 patients with 145 aneurysms in the posterior and distal anterior circulations, who treated with Leo stent, were collected in our three neurosurgical centers. Data on demographic information, aneurysm characteristics, procedural outcomes, postoperative course, and aneurysm occlusion were retrospectively analyzed. Results: After immediate surgery, 90 aneurysms (60.1%) were in complete occlusion (RROC 1 and OKM grade D), 29 aneurysms (20%) in good occlusions (RROC 2 and OKM grade C), 17.9% in incomplete occlusion (RROC 3a or OKM grade B) and there were no aneurysms in invalid occlusion (RROC 3b and OKM grade A). 112 patients with 117 aneurysms were received angiographic follow-up (mean 11.4 months), and the occlusion degree showed significant improvement (Z=-3.900, P<0.001). The rate of complete occlusion increased to 84.6% (99/117), meanwhile, good occlusion and incomplete occlusion dropped to 6.8% (8/117), and 8.6% (10/117), respectively. 14 cases (10.5%) had in-stent narrowing and 9 cases (6.8%) showed side branches injured. Cerebral hemorrhage occurred in 4 patients (3.0%), and symptomatic ischemic infarct occurred in 6 patients (4.5%). The finial permanent morbidity (mCS≥3) and mortality were 2.8% (3/133), 0.8% (1/133), respectively. There were 82 aneurysms in stent-assisted with coiling (SAC) group and 63 aneurysms in LEO stent monotherapy (LSM) group. Multiple aneurysms were all treated by LSM, and ruptured aneurysms were prone to be treated by SAC (χ2=7.767, P=0.005). More fusiform aneurysms (2=18.958, P< 0.01) and/or small size aneurysms (Z=-2.692, P=0.007) were in LSM group. Conclusions: The Leo stent is safe and effective for aneurysms located in the posterior and distal anterior circulations. The overall occlusion degree improved during follow-up by FD effect. The aneurysms in these areas should be treated by personalized measures.