Guide-wire entrapment by inferior vena caval filters: In vitro evaluation

PURPOSE: To study guide-wire engagement and entrapment by inferior vena caval (IVC) filters. MATERIALS AND METHODS: Patterns of engagement were determined in six IVC filters with four commonly used guide wires in a simulated IVC. Force required to disengage guide wires from filters was measured. RESULTS: Eleven engagement patterns were identified with J-tipped guide wires; straight guide wires never engaged. The Simon-Nitinol filter engaged guide wires with the highest frequency (P < .05). The 15-J guide wire was engaged most frequently overall (P < .0005) but disengaged with forces not significantly different (P > .05) from those required to open the J. Entrapment occurred with only the Vena-Tech (VT) and 12-F stainless steel Greenfield (12SSG) filters and the 1.5-J and 3-J guide wires. The former guide wire became entrapped regardless of engagement pattern; the latter became entrapped only when engaged in the hole in the apex of the 12SSG and VT filters. CONCLUSION: Guide wires with a J tip 3 mm or less in radius are at risk for entrapment by the 12SSG and VT filters.