The background and role of catheter-directed thrombolysis evolving procedures for acute iliofemoral deep venous thrombosis

Minimal invasive treatment such as early endovenous thrombus removal for iliofemoral deep venous thrombosis (DVT) emerged in the end of last century. The principle is catheter-directed thrombolysis (CDT) using either plasminogen activating agents alone, as ultrasound-assisted CDT, or in combination with mechanical devices as pharmaco-mechanical CDT. The interest for this treatment modality is the high rate of post-thrombotic syndrome (PTS) with anticoagulation (AC) alone, especially after iliofemoral DVT. Recently published randomized controlled trials (RCTs) comparing early thrombus removal with AC alone, as well as non-randomized studies, have demonstrated favorable rates, or at least a decrease of moderate and severe PTS, in favor of these procedures. This article will summarize the background and evolution of the procedures in the last three decades and discuss fundamental criteria for inclusion and exclusion, focusing on the procedures regarding thrombus age and location, technical issues, complications and results including different outcome measures for PTS, for which iliac DVT involvement is a massive risk factor to be prevented.

Should catheter-directed thrombolysis be monitored?

Catheter-directed thrombolysis for deep venous thrombosis is considered the basic treatment modality for intrathrombus removal. This method is preferably used in patients with iliofemoral deep venous thrombosis due to poor spontaneous recanalization in this segment, especially on the left side. The method was published almost 25 years ago and has gained ground in the treatment because of poor results from systemic thrombolysis and because of the possibility of stenting any underlying iliac obstruction during the procedure. However, the publications of catheter-directed thrombolysis reveal a great heterogeneity concerning catheter-directed thrombolysis technique and the lack of high quality evidence about monitoring as a tool to minimize the risk of bleeding and pulmonary embolism. Strict inclusion and exclusion criteria, correct composition and infusion of thrombolysis agent, imaging thrombus clearance during catheter-directed thrombolysis, ensuring flow enhancement during the bedridden situation, careful evaluation of indication for stenting based on imaging, and sufficient conversion to anticoagulation treatment following catheter-directed thrombolysis are essential. The aim of this paper is to discuss different treatment aspects of catheter-directed thrombolysis for iliofemoral thrombosis and to suggest a monitoring model for future treatment.