Inferior vena cava filters prevent pulmonary emboli in patients with metastatic pathologic fractures of the lower extremity.

The records of 47 consecutive patients with metastatic pathologic fractures of the lower extremity were analyzed with respect to thromboembolic complications. All patients were unable to receive pharmacologic deep venous thrombosis prophylaxis, and were stratified into two groups, based on use of an inferior vena cava filter. Group I (n = 24) consisted of patients who had an inferior vena cava filter plus mechanical deep venous thrombosis prophylaxis (compression stockings and sequential compression boots); Group II (n = 23) consisted of a group of patients receiving only mechanical deep venous thrombosis prophylaxis. All patients had routine lower extremity venous duplex imaging preoperatively, postoperatively, and before hospital discharge. At final followup, patients were examined for deep venous thrombosis and reviewed for thromboembolic events. At a mean followup of 11.5 months, Group I had two detectable deep venous thromboses and no pulmonary emboli; Group II had one detectable deep venous thrombosis and five pulmonary embolisms. In Group II, 40% (two of five) of pulmonary embolisms were fatal, yielding an 8.7% (two of 23) group mortality rate. Overall, the entire group had an approximately 17% deep venous thrombosis rate. Only 6.4% (three of 47) of deep venous thromboses were detectable by standard duplex imaging. The majority of deep venous thromboses (five of eight, 62.5%) were nondetectable by duplex imaging. Overall, a 4.3% (two of 47) death rate was attributable to pulmonary embolism. In contrast, an 8.6% (four of 47) mortality rate occurred in Group II alone. All pulmonary embolisms occurred in patients who did not receive an inferior vena cava filter. The majority of venous thromboses (62.5%) were not detectable on duplex scanning, therefore were thought to arise from the pelvic venous system. Complications related to inferior vena cava filter insertion were minimal. For patients with metastatic pathologic fractures of the lower extremities who are unable to receive pharmacologic deep venous thrombosis prophylaxis, the use of inferior vena cava filters, in conjunction with standard mechanical deep venous thrombosis prophylaxis, is a procedure that has a low risk and is useful adjunct to prevent fatal pulmonary embolisms.