What is an ALN inferior vena cava (IVC) filter?

Updated: Oct 31, 2020
  • Author: Gary P Siskin, MD; Chief Editor: Kyung J Cho, MD, FACR, FSIR  more...
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The ALN filter has been available in Europe since 1997. It was approved by the FDA in 2008.

This filter is a conical filter made from 9 variable-length wires of 316L stainless steel. The upper level has 6 arms with hooks for anchoring and 3 longer legs for centering. The introducer sheaths are 7F, and the filters are preloaded in a holder. The filter kits are packaged separately for deployment for femoral, jugular, and brachial approaches.

Retrieval is via the jugular approach. The introducer set is 9F OD. The retrieval kit is a forceps design, cone-retrieval system with 8 stainless wires without any plastic cone.

In 2007, in a series of 220 patients with ALN filter placement with an 18-month follow-up, Mismetti et al reported filter tilt was seen in 12 of 212 (5.7%) during placement. [97] Fatal PE occurred in 5 (2.3%) within 24 hours to 11 days following placement. Filter retrieval was successful in 55 patients, with a mean indwell time of 51 days (range, 6-352 d); 4 of these patients required a second attempt because of filter thrombosis. [97]

In 2008, Pellerin et al reported successful retrieval was achieved in 122 of 123 patients (99%), with a mean indwell time of 93 days (range, 6-722 d). [57] Severe tilting was seen in 6 cases (5%), including 1 failure in retrieval. There was no filter migration, fracture, or IVC penetration. [57]

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