Complex Inferior Vena Cava Filter Retrievals: Success Rate and Predictors of Adverse Events at a Large Specialized Referral Center.

Background: Specialized inferior vena cava (IVC) filter referral centers can achieve improved retrieval outcomes, potentially facilitating complex retrievals after long filter dwell times. Objective: To determine the success rate of complex IVC filter retrievals at a large specialized IVC filter referral center and to identify predictors of adverse events during complex retrievals. Methods: This retrospective study evaluated patients who underwent complex IVC filter retrieval from March 2014 to June 2018 at a large regional health system with specialized complex retrieval referral centers and interventional radiologists having expertise in such procedures. Complex retrievals methods included a range of loop snare, coaxial sheath, forceps, and snare techniques. Data were collected from the electronic medical record. The complex retrieval success rate was determined. Factors associated with adverse events during retrieval procedures were explored. Results: The study included 125 patients (mean age, 60 years; 51 women, 74 men). The mean filter dwell time at time of retrieval was 47.5 months (median, 21.8 months). The complex retrieval success rate was 99.2% on the first attempt and 100.0% overall. A total of 11.2% (14/125) of patients experienced an adverse event during retrieval, including 10.4% (13/125) with minor and 0.8% (1/125) with major events. Prolonged dwell time was the only indication for complex retrieval that was significantly associated with adverse events (adverse event rate of 16.7% for patients with this indication vs 5.1% for patients without this indication; p=.04). In multiple regression analysis, the only significant independent predictor of adverse events was a filter dwell time ≥5 years (odds ratio=6.98, 95% CI 1.64-29.81, p=.009). Conclusion: High retrieval success rates can be achieved in patients with long dwell times in the context of a specialized referral system with expertise in complex retrieval methods. Nonetheless, longer dwell times are associated with adverse events during the retrieval procedures. Clinical Impact: The observations support performing early filter retrieval and referring patients with prolonged dwell times to specialized centers.