Disclosed herein is a removable vena cava filter for capturing thrombi in a blood vessel. The filter includes a plurality of primary struts having first ends attached together at their first ends. The filter also includes a plurality of secondary struts spaced between the primary struts and having third ends attached together along the longitudinal axis. Each secondary strut freely extends from the third end to a fourth end avoiding contact with other secondary struts and primary struts. The filter has an expanded configuration, in which the second arcs of the plurality of secondary struts may define a cavity having a hemiovoid shape, such that an ovoid formed from a reflection of the hemiovoid shape of the cavity does not extend beyond the end boundary of the filter defined by the second ends of the primary struts.
