Systemic Thrombolytic Resistance in Antithrombin III Deficiency Rescued by Catheter‐Directed Thrombolysis: A Case Report

This case highlights systemic thrombolysis failure associated with AT III deficiency and demonstrates that CDT can serve as an effective, low-bleeding-risk rescue therapy for extensive DVT when systemic treatment is inadequate. These findings underscore the importance of early recognition of AT III deficiency and consideration of catheter-based intervention in similar high-risk settings.