Greenfield stainless steel vena cava filters on computed tomography follow-up

Objective: The objective of this study was to evaluate complications of Greenfield (Boston Scientific, Marlborough, Mass) stainless steel inferior vena cava (IVC) filters on follow-up computed tomography (CT) imaging and to elucidate associated risk factors. Methods: Ninety-three patients with CT studies obtained for other reasons after Greenfield IVC filter placement (2007-2014) were retrospectively studied. Greenfield filters were placed permanently in those with venous thromboembolism and an expected lifelong contraindication to anticoagulation or life expectancy <6 months. Patients' demographic data, procedural characteristics, and imaging studies were reviewed and factors associated with perforation rates were analyzed. Results: A total of 190 follow-up CT imaging studies were available for review. In total, filter-associated IVC thrombus (n = 10 [10.7%]) and pulmonary embolism breakthrough (n = 4 [4.3%)] were documented by contrast-enhanced CT. Perforation was evident in 18 patients (19.4%) with an average indwelling time of 256 days. No symptomatic perforation and no strut fracture were documented. There was no significant difference in perforation rate with respect to age of the patient (P = .61), sex (P = 1.00), or history of malignant disease (P = .40). The filter perforation rate and number of perforating struts were significantly higher in patients with longer indwelling time (>90 days) than in patients with shorter indwelling time (<90 days; P < .01). Caval cross-sectional areas of patients who experienced IVC filter perforations at >90 days were significantly smaller than those of nonperforated patients (284 vs 358 mm(2); P < .01). Conclusions: Stainless steel Greenfield filters remain a relatively safe option for patients requiring permanent mechanical filtration.