1Abdullah A. Shaikh

1Allegheny Health Network

Background(s):

Endovascular treatment options for deep vein thrombosis (DVT) are evolving and include mechanical thrombectomy and catheter-directed thrombolysis (CDT). Mechanical thrombectomy may be beneficial over CDT as it does not necessitate thrombolytics and has the potential to significantly reduce intensive care unit (ICU) monitoring and hospital resource burden. The real-world ClotTriever outcomes (CLOUT) registry is currently evaluating patient outcomes following treatment of lower extremity DVT in the United States. The goal of this sub-analysis is to assess the acute hospital resource burden associated with DVT treatment using the ClotTriever System (Inari Medical, Irvine, CA).

Material(s) and Method(s):

The prospective, multi-center CLOUT registry assesses the safety and effectiveness of the ClotTriever System for the treatment of proximal lower extremity DVT with no restrictions on thrombus chronicity. Patients with unilateral or bilateral DVT, prior history or treatment of DVT, provoked or unprovoked DVT, high bleeding risk, cancer, or pregnancy were included. The primary effectiveness endpoint is complete or near-complete (≥75%) thrombus removal as determined by core laboratory-adjudicated Marder scores. Per protocol, various resource measures were collected during index hospitalization and through 30 days.

Result(s):

Of the first 250 patients enrolled in the CLOUT registry, median age was 62 years, 53% were male, 23% had prior history of DVT, and 40% were at a high bleeding risk with thrombolytics. Almost all procedures were performed in a single session (99.6%) with a median of 4 device passes and a median thrombectomy time of 28 minutes. No patients required adjunctive thrombolytics. Adjuvant venoplasty was used in 73% and stents were placed in 47% of cases. Median blood loss was 50 mL. Complete or near-complete thrombus removal was achieved in 85% of limbs, including 51% with complete thrombus removal. Post-thrombectomy ICU stay was needed in 6 patients and the median post-thrombectomy hospital stay was 1 day. Through hospital discharge, the reintervention rate was 0.4%. Through 30 days, the hospital readmission rate was 7.6%, of which 3.1% were procedure-related.

Conclusion(s):

Interim results from the US-based CLOUT registry demonstrate that mechanical thrombectomy with the ClotTriever System can be performed in a single session and is associated with short thrombectomy times, no need for thrombolytics, low blood loss, minimal ICU usage, and low hospital readmission rate. Further, these results indicate that the ClotTriever System is effective at removing thrombus while imparting low acute burden on hospital resources. Enrollment to 500 patients and two-year follow-up are ongoing.