Catheter-directed thrombolysis for extensive iliofemoral deep vein thrombosis: review of literature and ongoing trials

ABSTRACT

In patients with extensive lower limb deep vein thrombosis (DVT) that, typically, extends into the iliofemoral veins, catheter-directed thrombolysis (CDT) can achieve faster and more complete thrombus lysis as compared with systemic thrombolysis, while providing an acceptable safety profile through administration of lower doses of thrombolytic agents. Through a reduction in thrombus burden, CDT has the potential to mitigate the risk for post-thrombotic syndrome by restoring venous patency and preserving venous valve function. The efficacy of CDT may be improved by adjunctive approaches that include percutaneous mechanical thrombectomy, angioplasty with or without stenting, and ultrasound-assisted CDT. CDT may also have a specific therapeutic role in the management of iliofemoral DVT involving patients who are pregnant or with May–Thurner syndrome. This article summarizes the literature in this area and discusses recently completed and ongoing randomized trials on the use of CDT in patients with extensive lower limb DVT.

KEYWORDS:

• Catheter-directed thrombolysis
• thrombectomy
• angioplasty
• deep venous thrombosis
• pregnancy
• May–Thurner syndrome
• randomized controlled trials

Key issues

• Catheter-directed thrombolysis (CDT) has the potential to mitigate the risk for post-thrombotic syndrome in patients with extensive iliofemoral deep vein thrombosis (DVT) via restoration of venous patency and preservation of venous valve function and, therefore, may result in a reduction in thrombus burden.

• CDT also shows promise in patients with iliofemoral DVT who are pregnant or with the May–Thurner syndrome.

• Current data suggest that CDT appears to be associated with favorable long-term efficacy outcomes.

• It also has an acceptable safety profile as compared with systemic thrombolysis since a lower dose of thrombolytic agent is used.

• The efficacy of CDT can be further improved with the concomitant use of the available adjunctive therapies, which include percutaneous mechanical thrombectomy and angioplasty with or without stenting and ultrasound-assisted CDT.

• The role of a temporary inferior vena cava filter in this setting remains unclear.

• However, the fundamental question of which patients are most likely to benefit from CDT (with or without adjunctive therapy) remains unanswered.

• The results from two phase 3 randomized controlled trials, DUTCH CAVA and ATTRACT trials, will help inform best practices for the routine clinical use of CDT.

Notes

¹ Villalta score is a clinical measure that incorporates ratings of six clinician-rated venous signs (pretibial edema, skin induration, hyperpigmentation, redness, venous ectasia and pain on calf compression) and five patient-rated venous symptoms (pain, cramps, heaviness, paresthesia and pruritus) in the leg ipsilateral to a deep vein thrombosis. The severity is graded from 0 to 3 points (no, mild, moderate and severe) for each sign or symptom. According to ISTH recommendations, post-thrombotic syndrome was considered present if the Villalta score was >4 (5–9 = mild, 10–14 = moderate and >14 or presence of an ulcer = severe).[5]