BACKGROUNDPulmonary thromboembolism (PTE) is a serious disease often leading to disability and death. Percutaneous placement of an inferior vena cava (IVC) filter is an effective method to prevent fatal PTE caused by lower extremity deep venous thrombosis (LEDVT). We developed the ZQL-type retrievable vena cava filter. The aim of this study was to evaluate the safety and effectiveness of the ZQL-type filter for prevention of fatal PTE.

METHODSA total of 144 patients with indications for placement of an IVC filter received insertion of filters via a femoral (n = 37) or jugular (n = 107) vein approach. Abdominal X-ray and color Doppler ultrasonography of IVC were regularly performed to visualize the position and condition of the IVC filter following filter placement. If thrombi in the lower extremity deep veins were removed within 2 weeks, the filter retrieval procedure was performed after an abdominal radiograph, an inferior vena cavogram and a pulmonary angiography. Otherwise, the filter should be kept permanently in place with regular follow-up inspections.

RESULTSOne hundred and forty-four filters were implanted at the target sites with a success rate of 98.61% for one-time placement and 100% for two-time placement. Of the 137 patients followed up (follow-up rate, 95.14%), 43 patients had filters retrieved during a period of between 7 and 14 days (median, 12 days) following filter placement. The remaining 94 patients were followed for 7 days to 39 months (median follow-up period, 17 months). No filter migration or tilt, filter fracture or IVC perforation was observed. No obstruction of IVC occurred. No symptomatic PTE developed during the follow-up period.

CONCLUSIONThe ZQL-type retrievable vena cava filter is a safe and effective device to prevent PTE. This filter possesses a distinctive stent-shape, stable design, high capture efficacy, and is easy to insert and retrieve and thus is suitable for clinical application.