Clinical experience and safety of catheter-directed thrombolysis using monteplase for acute iliofemoral deep vein thrombosis: a retrospective single-center analysis.

Iliofemoral deep vein thrombosis (DVT) is associated with an increased risk of post-thrombotic syndrome (PTS), despite anticoagulant therapy. However, since the coronavirus disease 2019 pandemic, no thrombolytic agent has been available under the national health insurance system for catheter-directed thrombolysis (CDL) of DVT in Japan. To evaluate the clinical outcomes of CDL using monteplase in patients with acute iliofemoral DVT and severe symptoms. Among 1,437 consecutive patients with lower-extremity DVT from August 2022 to December 2024 at a single center, 11 consecutive patients with acute symptomatic iliofemoral DVT treated with CDL using monteplase were retrospectively analyzed. The median age was 51 years, 64% of patients were male, and the median Villalta score at diagnosis was 8.5. The median duration from symptom onset to therapy was 7 days. The median total dose of monteplase was 3.55 million IU, and the median duration of therapy was 4.5 days. Patency of the treated iliac vein immediately after CDL was achieved in all lesions. Treatment-related adverse events occurred in 1 patient (9.1%), consisting of a subcutaneous hematoma, and no patients required blood transfusion. At 1 year after CDL, the Villalta scores ranged from 0 to 3 in all patients, and no patients developed PTS. Although 1 patient showed a mild decline in quality of life, no clinically significant deterioration was observed overall. CDL using monteplase may represent a feasible treatment option for carefully selected patients with acute symptomatic iliofemoral DVT in Japan. Larger studies are warranted to confirm these findings.