Abstract: AIM: To investigate the necessity of placing inferior vena cava filter in systemic thrombolytic therapy for patients with acute deep vein thrombosis. METHODS: Retrospectively summarized the clinical data of patients who received urokinase for deep vein thrombosis in the Third Xiangya Hospital of Central South University from September 2006 to April 2020, and discussed the necessity of placing inferior vena cava filter. RESULTS: A total of 549 patients were enrolled, including 294 patients in the filter group (154 males, 140 females) and 255 patients in the non-filter group (126 males, 129 females). Among 268 cases of proximal DVT in the filter group, thirty-five cases were complicated with pulmonary embolism before thrombolysis; and there were 218 cases of proximal DVT in the non-filter group and 16 cases of pulmonary embolism before thrombolysis, with statistical difference between the two groups (P=0.038 and 0.023, respectively). The total amount of urokinase in the filter group was (1 636.3±910.0) thousand units, and that in the non-filter group was (1 490.2±777.2) thousand units, with statistical difference between the two groups (P=0.045). However, there were no statistical differences in the days of use of urokinase and the proportion of patients with adequate anticoagulation. In this study, among 255 patients in non-filter group underwent thrombolysis, only 1 patient developed pulmonary embolism after thrombolysis (P=0.282). CONCLUSION: Inferior vena cava filter is not always necessary for patients with acute deep vein thrombosis during systemic thrombolytic therapy.

Key words: vena cava filters, venous thrombosis, urokinase thrombolysis, pulmonary embolism