Six-Month Outcomes of Mechanical Thrombectomy for Treating Deep Vein Thrombosis: Analysis from the 500-Patient CLOUT Registry.

Abstract

Mechanical thrombectomy for the treatment of deep vein thrombosis (DVT) is being increasingly utilized to reduce symptoms and prevent postthrombotic syndrome (PTS), but more data on clinical outcomes are needed. Mechanical thrombectomy was studied in the ClotTriever Outcomes (CLOUT) registry with 6-month full analysis outcomes reported herein. The CLOUT registry is a prospective, all-comer study that enrolled 500 lower extremity DVT patients across 43 US sites treated with mechanical thrombectomy using the ClotTriever System. Core-lab assessed Marder scores and physician-assessed venous patency by duplex ultrasound, PTS assessment using Villalta score, venous symptom severity, pain, and quality of life scores through 6months were analyzed. Adverse events were identified and independently adjudicated. All-cause mortality at 30days was 0.9%, and 8.6% of subjects experienced a serious adverse event (SAE) within the first 30days, 1 of which (0.2%) was device related. SAE rethrombosis/residual thrombus incidence was 4.8% at 30days and 8.0% at 6months. Between baseline and 6months, venous flow increased from 27.2% to 92.5% of limbs (P < 0.0001), and venous compressibility improved from 28.0% to 91.8% (P < 0.0001), while median Villalta scores improved from 9.0 at baseline to 1.0 at 6months (P < 0.0001). Significant improvements in venous symptom severity, pain, and quality of life were also demonstrated. Outcomes from iliofemoral and isolated femoral-popliteal segments showed similar improvements. Outcomes from the CLOUT study, a large prospective registry for DVT, indicate that mechanical thrombectomy is safe and demonstrates significant improvement in symptoms and health status through 6months. Level of Evidence 3: Non-randomized controlled cohort/follow-up study.