A Modified Wire-Loop Snare Technique to Retrieve Inferior Vena Cava Filters with Severe Tilt and Embedded Hooks

Background: Severe tilt with embedded hook is a common obstacle to successful retrieval of the retrievable inferior vena cava (IVC) filter. One reason leading to retrieval failure is the guide wire and catheter that could not be guided between the IVC wall and filter neck. Objectives: The aim of this study is to investigate the feasibility of a modified wire-loop technique for retrieval of inferior vena cava filters with severe tilt and embedded hooks. Patients and Methods: Between September 2013 and November 2017, 156 patients underwent IVC filter implantation including drum-type filter (OptEase) and conical filter (Celect). Preoperative CT angiography or intraoperative angiogram revealed that three drum-type filters and four conical filters tilted severely and could not be retrieved using a conventional snare technique. We performed a modified wire-loop snare technique. The end of 5F pigtail catheter was cut off and remade to be fishhook-like. The pigtail catheter and 0.035-inch-long soft guide wire were introduced into the inferior vena cava (IVCF) through long sheath. A 5F vertebral catheter and a snare were advanced into the IVCF simultaneously. The pigtail catheter directed the guide wire to pass through the interstice of the cava wall and filter neck. The leading end of the wire was snared by 5F vertebral catheter and the snare to form a loop. Then the loop snared the hook. If there was no interstice between the filter neck and cava wall, the homemade catheter would then direct the guide wire to pass through the interstice of separate filter struts. The conventional technique was performed or the long sheath advanced over the wire-loop to retrieve the filter directly. Results: Four conical filters were retrieved by snaring the hook directly. The filter hook of drum-type filter was stretched away from the cava wall in two cases, and then, the conventional snare technique was performed successfully. The long sheath was advanced over the wire-loop to retrieve the filter directly in one case. Conclusion: The modified wire-loop snare technique is simple and effective and can be used to retrieve both conical and drum-type filters with severe tilt and embedded hooks.