Aim: To evaluate the diagnosis and treatment strategies for the iliac vein compression syndrome (IVCS) and the factors that affect the treatment outcome.Methods: In total,69 patients with IVCS were enrolled in the study.The patients underwent computed tomography (CT) venography before treatment.CT observations included assessment of the iliac venous channel sagittal diameter (IVCD) before the lower lumbar vertebra,causes of oppression,thrombus density,and embolization range.The patients with IVCS were divided into the simple IVCS (sIVCS,n =22),lumbar degeneration-related type IVCS (dIVCS,n =33),and IVCS of other causes (oIVCS,n 14) including lumbar fracture,hematoma of infection,and abscess wraping around and compressing the iliac vein,groups.The treatment methods included target venous catheter-directed thrombolysis (CDT),a mechanical breaking and sucking treatment for the thrombi,followed by balloon dilatation and iliac vein stent implantation.The factors that may possibly affect the treatment outcomes included IVCS type,duration of disease,thrombus hardness,embolization length,and treatment regimen.Logistic regression was used to analyze the factors that affected the therapeutic efficacy.Results: At the first stage,CDT was only effective in 15 cases (5 dIVCSs and 10 oIVCSs) and was ineffective in the remaining 54 cases,which required further mechanical breaking and sucking of the thrombi and intravenous balloon dilatation.In the second stage,combination of thrombi breaking and suction and balloon dilatation was preliminarily effective in 26 cases (6 sIVCSs,16 dIVCSs and 4 oIVCSs),but during follow-up from 1 to 6 months,treatment was considered futile for 9 recurrent cases (3 sIVCSs and 6 dIVCSs).So,28 cases of preliminary ineffective treatment and 9 relapse in the second stage were arranged to the third stage of treatment by iliac vein stent implantation.All 37 cases were treated effectively and achieved a satisfactory iliac vein patency,and were followed-up for 24 months without recurrence.Logistic regression analysis showed that IVCS type (β =4.14;Wald test,P ＜ 0.01),duration of illness (β =-5.33;Wald test,P =0.02),thrombus density (β=-6.46;Wald test,P =0.01),embolization length (β=2.74;Wald test,P =0.03),and treatment regimens (β=11.92;Wald test,P =0.01) all had a significant effect on the treatment outcomes.Conclusion.: The selection of a suitable intervention treatment regimen for different types of IVCS may aid in improving the curative effect.