Large-Bore Thrombectomy Using Inari Triever Aspiration Catheter for Thrombosed Aneurysmal Hemodialysis Access Outflow Vein

Abstract

Outflow vein aneurysms are common in long-standing arteriovenous hemodialysis accesses and may pose challenges in endovascular treatment of a thrombosed circuit [1]. These aneurysmal segments are often difficult to clear adequately, leading to failed thrombectomy, pulmonary embolism, and access site abandonment [2]. The FlowTriever System (Inari Medical; Irvine, California) is designed for treatment of venous thromboembolism in the peripheral vasculature and pulmonary arteries. This report describes the use of a 20-French Triever Aspiration Catheter in a hemodialysis circuit to perform thrombectomy of a thrombosed outflow venous aneurysm. Institutional review board approval was not required for preparation of this report. A 40-year-old woman on hemodialysis via a right brachial-axillary arteriovenous graft (AVG) created two years prior presented with recurrent graft thrombosis within the past 4 weeks. The procedure was performed under general anesthesia given a history of pulmonary hypertension (institutional requirement). Ultrasound demonstrated thrombosis of the 6-mm AVG with the thrombus extending centrally into an aneurysmal brachioaxillary outflow vein segment measuring up to 2.8 cm. A 25-gauge needle was used to inject 6 mg of tissue plasminogen activator within the AVG and venous aneurysm. The right internal jugular vein was accessed to establish a retrograde route into the outflow vein (Fig. 1A). Given the thrombus burden within the aneurysm, the decision was made to perform a large-bore thrombectomy. Over a stiff wire, a 20-French DrySeal Flex Introducer Sheath (W. L. Gore & Associates; Flagstaff, Arizona) was advanced into the axillary vein. A 20-French Triever Aspiration Catheter (Triever20) was advanced to the central end of the thrombus (Fig. 1B). Three aspirations were performed. No nitinol mesh disks were used. Postthrombectomy venography was performed (Fig. 1C and D), demonstrating complete removal of the original thrombus in the venous aneurysm and mobilization of a small clot from a more peripheral segment. The Triever 20 was removed, and retrograde access to the arterial anastomosis was obtained. Following a balloon sweep across the arterial anastomosis and AVG, circuit patency was restored. Two 8-mm Covera stent-grafts (Bard Medical; Covington, Georgia) were deployed in an overlapping fashion across the venous anastomosis to address the underlying high-grade ([ 50%) stenosis (Fig. 1E). Following angioplasty using an 8-mm balloon throughout the AVG and stent-graft construct, completion angiography demonstrated a widely patent circuit (Fig. 1F). Hemostasis was achieved with manual compression. No neck hematoma was noted, and the patient completed multiple sessions of hemodialysis successfully prior to discharge. In treating a thrombosed aneurysmal segment, simple balloon maceration and mobilization of thrombus through a smaller central venous segment may be ineffective and time consuming [3]. Aggressive manipulation of thrombus may lead to clinically significant pulmonary emboli [2], which is an important consideration especially in patients with & David S. Shin [email protected]