ObjectiveTo evaluate the safety and mid-to-long-term outcomes of catheter-directed thrombolysis (CDT) in combination with percutaneous mechanical thrombectomy (PMT) followed by stent placement treatment for acute proximal deep vein thrombosis (DVT) complicated by iliac vein compression syndrome (IVCS), and to identify risk factors associated with primary stent restenosis. MethodsA retrospective study was conducted. The patients diagnosed with acute proximal DVT and concurrent IVCS who underwent CDT in combination with PMT followed by stent placement at the First Affiliated Hospital of Chongqing Medical University from January 2018 to December 2021 were included. The demographics, clinical history, and procedural data were collected retrospectively. The postoperative follow-up assessments using color Doppler ultrasound were performed at 3, 6, and 12 months, and annually thereafter. The primary and secondary stent patency rates were evaluated. The univariate and multivariate Cox proportional hazards regression models were employed to assess risk factors for primary stent restenosis. ResultsA total of 188 patients who met the inclusion and exclusion criteria were enrolled, underwent CDT combined with PMT and stent implantation, and completed follow-up. During the follow-up, the restenosis occurred in 26 patients. The cumulative primary patency rates at 3, 6, 12, 24, 36, and 48 months after surgery were 100%, 98.9%, 92.5%, 88.3%, 86.7%, and 86.2%, respectively. The multivariate Cox proportional hazards regression analysis confirmed that a history of previous DVT [β=1.44, HR (95%CI)=4.21 (1.73, 10.28), P=0.002], implantation of two or more stents [β=2.47, HR (95%CI)=11.85 (1.66, 84.63), P=0.014], stent crossing the inguinal ligament [β=2.30, HR (95%CI)=9.92 (1.87, 52.78), P=0.007], and stent length [β=–0.02, HR (95%CI)=0.98 (0.97, 0.99), P=0.003] were independent risk factors for primary restenosis. ConclusionsThe findings of this study suggest that CDT combined with PMT and stent implantation is a safe and effective strategy for treating acute proximal DVT complicated by IVCS. Close attention should be paid to the occurrence of restenosis in patients with two or more stents, longer stent lengths, stents crossing the inguinal ligament, and a history of previous DVT.