The present invention provides a removable vena cava filter for capturing thrombi in a blood vessel. The filter (10) comprises a plurality of primary struts (12) having first ends attached together along a longitudinal axis. Each primary strut has an arcuate segment extending from the first end to an anchoring hook (26). The primary struts are configured to move between an expanded state for engaging the anchoring hooks with the blood vessel and a collapsed state for filter retrieval or delivery. Each primary strut is configured to cross another primary strut along the longitudinal axis in the collapsed state such that the arcuate segments occupy a first diameter (D1) greater than a second diameter (D2) occupied by the anchoring hooks in the collapsed state for filter retrieval or delivery.