LAUSR

Intravascular tissue sampling may be percutaneous, endovascular, or surgical [1]. Small-volume transvenous biopsies have been described using 5.5and 7-French biopsy forceps [1]. Small volume sampling, however, may result in lower diagnostic yields and be limited by crush artifact. The ClotTriever thrombectomy system (Inari Medical; Irvine, CA) has been used for the extraction of large-volume thrombotic and embolic materials in peripheral and central veins [2]. This report describes the results of histopathologic analysis on specimens collected via ClotTriever-mediated thrombectomy. Institutional review board approval was obtained for preparation of this report. Twenty-six consecutive patients (14 males, 12 females; mean age 54.4 ± 15.3 years) underwent ClotTriever-mediated thrombectomy for symptomatic venous thrombosis with endovascular tissue samples sent for pathologic analyses. Twenty-three patients presented with swelling, fifteen with pain, two with fever, and one with respiratory failure. Fifteen patients underwent thrombectomy of the inferior vena cava or lower extremity deep veins, and eleven patients underwent thrombectomy of the thoracic central veins or upper extremity deep veins. Technical success, described as extraction of intravascular materials adequate for desired pathologic and/or microbiologic analysis, was obtained in all patients. There were no intraprocedural adverse events. Of the removed samples, seventeen were benign (i.e., bland thrombus of various chronicity), seven were malignant, and two were infectious. Malignancies included non-small cell adenocarcinoma from lung primary (n = 2), EBV ? large B-cell lymphoma (n = 1), papillary thyroid carcinoma (n = 1) [3], acute T-cell lymphoblastic leukemia (n = 1), follicular lymphoma (n = 1), and colorectal adenocarcinoma (n = 1) [4]. Infections were due to Staphylococcus aureus (n = 2). 2/7 of malignant thrombus samples demonstrated enhancement on computed tomography (CT) or magnetic resonance-based imaging studies within thirty days of the thrombectomy procedures. Clinical success, described as resolution of presenting systems, was achieved in all patients.