[Relationship between Aneurysm Volumetric Changes and Endoleaks after Endovascular Abdominal Aortic Aneurysm Repair].

Objective To evaluate the relationship of volumetric changes and endoleaks after endovascular aneurysm repair(EVAR)for abdominal aortic aneurysms(AAAs). Methods We retrospectively evaluated the clinical and imaging data of 54 patients who had underwent EVAR within 1 month after their aneurysms were detected.All patients received abdominal and pelvic enhanced computed tomography(CTA)for two follow-up visits in Peking Union Medical College Hospital from July 2014 to February 2019.Three-dimensional volumes and maximum diameters on axial CT of the aortic aneurysms were calculated by dedicated semi-automated 3D segmentation software before surgery(V0 and D0),in the 4 th postoperative month(V1and D1),and in the 12 th postoperative month(V2and D2),respectively.The presence or absence of endoleak for each patient with the V1/V0,V2/V0,and V2/V1 were calculated to assess the significance of volume changes with respect to endoleaks and the correlation between volume changes and maximum diameter changes on axial CT images. Results Of the 54 patients,endoleaks were found in 11 patients at the first follow-up visit(4 months after surgery),among whom 8 patients were arranged a second follow-up visit(12 months after surgery),during which endoleaks were found in 5 patients.Fifteen of 43 non-leaked patients underwent a second CTA examination,which revealed endoleak in one case.Patients who did exhibit endoleaks[n =11,V1/V0=1.086(1.033,1.116)]showed significant increases in aneurysm volume when compared with those who did not exhbit endoleaks[n =43,V1/V0=1.019(0.970,1.065)]at the first follow-up visit(Z=-2.695,P=0.007),although no significant difference was found with regard to volume changes between endoleaks(n=6,V2/V0=1.1±0.2,V2/V1=1.0±0.1)and non-endoleaks(n=17,V2/V0=1.0±0.1,V2/V1=1.0±0.1)at the second follow-up visit(t=0.725,P=0.476)as well as between these two follow-up visits(t=-0.021,P=0.984).V0 and D0 were moderately correlated with V1 and D1,respectively(r=0.5,P<0.001)and strongly correlated with V2 and D2,respectively(r=0.8,P<0.001).V1 and D1 were strongly correlated with V2 and D2,respectively(r=0.8,P<0.001). Conclusions The changes of aneurysm volume cannot reliably reflect the occurrence of endoleaks.The change of maximum axial diameter of aneurysm has certain correlation with the changes of aneurysm volume.