Vena Tech-LGM filter: long-term results of a prospective study.

Efficiency and tolerance of the Vena Tech-LGM filter were assessed in 142 patients prospectively studied during a 2-6-year follow-up period. No patients were lost to follow-up, and 137 (91.3%) scheduled control examinations were performed. Fifty-three patients died of causes unrelated to thromboembolic disease. Pulmonary embolism was suspected in five surviving patients (3.5%). Sixteen retractions (18.4%), 16 intracaval migrations (18.4%), and one tilt were observed. Filter patency studied at Doppler ultrasonography, with or without phlebocavography, gave the following results according to the Kaplan-Meier actuarial method: 92% patency after 2 years of follow-up, 80% after 4 years, and 70% after 6 years. Vena Tech-LGM filter obstruction was related to retraction (P < 10(-6)) or distal migration (P < .004). Occurrence of trophic disease in the lower limbs during the follow-up period was related to the initial level of deep venous thrombosis (P = .03) and had no relation to the patency of the filter. The filter was effective in preventing pulmonary embolism, with 70% demonstrating long-term patency, and no deleterious effects were imputed to obstructions observed during follow-up.