When to suspect the need for forceps: Advanced filter retrieval techniques are often required with prolonged filter dwell times

Inferior Vena Cava (IVC) filters have been associated with an increased risk of recurrent deep vein thrombosis (DVT) and no difference in the rate of recurrent pulmonary embolism (PE) leading to National Quality Forum performance measures for assessment of IVC filter removal. The purpose of the current study is to determine if the dwell time of IVC filters is predictive of the need for advanced retrieval techniques. Patients who had IVC filters placed and retrieved between January 2015 and August 2016 were included. Patients were separated into two groups based on instruments needed for filter retrieval: standard instruments and advanced instruments. Standard instruments included the contents of the Cook IVC filter retrieval kit and advanced instruments consisted of any additional tools. Mean, median, and standard deviation of the time between filter placement and retrieval were then calculated between the two groups. Additionally, dwell time was divided into 3 months, 3-6 months, 6-12 months, >1 year, and >2 years to assess need for advanced retrieval techniques. Significance between groups was determined using an unpaired T-test of unequal variance. 128 of 130 patients (98.5%) successfully had their filter retrieved. Advanced techniques were required in 28 patients (21.5%) who underwent retrieval and 2 of those could not be retrieved. In the 7 patients (6%) that required a second attempt at retrieval, 5 patients (83%) required advanced techniques. The mean IVC filter dwell time for standard retrieval techniques was 180 days (median 148, ± SD 156.4) compared to 412.3 days in the advanced technique group (median 147, SD ± 227.8) (p = 0.04). Advanced techniques were required more often with increasing dwell times; 15% at 3 months, 20% at 3-6 months, 22% at 6-12 months, 40% at >1year. In those patients with a filter dwell time of greater than 2 years, 5 of 7 (71%) required advanced retrieval techniques compared with 23 of 123 (19%) with dwell time less than 2 years (p = 0.0012). Prolonged IVC filter dwell times are associated with increasing requirements for advanced retrieval techniques, most significantly when the dwell time exceeds 2 years.