Analysis Of Risk Factors Of Iliac Limb Occlusion After Endovascular Repair In Abdominal Aortic Aneurysm

Objective:To analyze the influencing factors of iliac limb occlusion(endograft limb occlusion)after abdominal aortic aneurysm endovascular repair(EVAR),especialy investigate the anatomical related risk factors,in order to provide theoretical reference in clinical prevention and treatment for iliac limb occlusion as well as reduce its incidence.Methods:A retrospective analysis of 146 patients diagnosed with infrarenal abdominal aortic aneurysm(IAAA)in the People’s Hospital of Xin jiang Uygur Autonomous Region from January 2008 to March2018 that underwent the EVAR treatment.According to endograft limb occlusion,they divided into iliac limb occlusion group and iliac limb non-occlusion group.The single factor analysis was performed on the general clinical factors and anatomical factors that may affect the iliac limb occlusion,and the multivariate logistic regression analysis was performed wih the variables with statistical differences.Results:According to the study requirements,146 patients with IAAA underwent EVAR treatment,17patients(11.6%)in the iliac limb occlusion group and 129 patients(88.4%)in the iliac limb non-occlusion group.Univariate analysis showed that:history of chronic bronchitis(χ~2=3.880,P=0.049),history of hyperlipidemia(χ~2=7.320,P=0.007),preoperative NEUT(%)(z=2.459,P=0.014),preoperative APTT(S)(z=2.004,P=0.045),preoperative PA(%)(z=2.084,P=0.037),Surgical approach(open exposure)(χ~2=7.320,P=0.007),operative time(min)(z=-2.935,P=0.003),degree of right common iliac artery diameter(≤12 mm,12mm~16 mm,≥16 mm)(χ~2=6.562,P=0.038),preoperative iliac artery stenosis or calcification≥50%(χ~2=26.907,P<0.001),preoperative iliac artery twist Angle≥60°(χ~2=13.924,P=0.001),postoperative iliac artery outflow tract stenosis(χ~2=16.318,P<0.001),postoperative internal iliac artery outflow tract occlusion(χ~2=7.127,P=0.028),and postoperative distal endograft extension to external iliac artery(χ~2=6.368,P=0.041)were correlated with postoperative iliac limb occlusion,and with statistical difference(P<0.05).Multivariate logistic regression analysis indicate that operative approach(open exposure)(OR=15.121,95%CI:1.841~124.197,P<0.05);postoperative iliac artery outflow tract stenosis(OR=10.099,95%CI:1.156~88.257,P<0.05);preoperative iliac artery stenosis or calcification≥50%(OR=7.727,95%CI:1.045~57.149,P<0.05);preoperative iliac artery twist Angle≥60°(OR=5.258,95%CI:1.055~26.198,P<0.05)were the risk factors for iliac limb occlusion after EVAR treatment(OR>1)and no protective factors were found(OR<1).Conclusions:Iliac limb occlusion after EVAR is related with preoperative severely splayed iliac artery angulation≥60°,preoperative iliac artery stenosis or calcification≥50%,and postoperation iliac artery outflow tract stenosis.The choice of surgical approach(open exposure)and endograft extension to external iliac artery should be considered as the result of the complex anatomical conditions of the iliac artery rather than the causing of iliac limb occlusion.Preoperative strict screening of iliac artery anatomical conditions,reasonable surgical approach selection,intraoperative individualized auxiliary intervention,and postoperative follow-up management are helpful to reduce the incidence of iliac branch occlusion after EVAR.