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Longer inferior vena cava filter dwell time increases standard retrieval failure rate
Inferior vena cava filters that have been in place for longer than 7 months are less likely to be retrieved using standard retrieval techniques, published data suggest.
In a prospective, single-center study of 762 retrieval procedures (mean age, 56 years; 49% men) performed from January 2009 to April 2015, 98% were successful. Standard retrieval techniques were sufficient in 82% or procedures, but advanced techniques were required in 18%.
In univariable logistic regression analysis, filter dwell time was the only factor associated with standard retrieval failure, which increased the need for use of advanced techniques (OR = 1.08; 95% CI, 1.05-1.1). Further, the researchers identified a dwell time of 7 months as the point at which standard retrieval failure rate began to increase significantly. At 7 months, the failure rate with standard techniques was 40.9% and continued to increase thereafter, according to spline function regression analysis.
The rate of adverse events was 2%, with three major and 15 minor events occurring during the study period.
“Devices that have been in place for extended periods of time potentially encounter prolonged exposure to multivector respiration-based caval biomechanics, resulting in metal fatigue, thereby increasing the risk of fracture and en bloc or component migration/embolization,” Kush R. Desai, MD, from the department of radiology, Northwestern University Feinberg School of Medicine, and colleagues wrote. “Thus, because of low retrieval rates, any potential benefit of a device optimally designed for limited use may be offset by the increased risk of complications associated with prolonged or often indefinite implantation.”
The researchers highlighted several limitations of their study, including its single-center nature, use of multiple filter types and the influence of operator preference on the use of specific advanced techniques. Additionally, more than 90% of patients had a filter in place for less than 10 months, preventing robust analysis of the retrieval rates associated with longer dwell times.
“Based on our data, we have defined prolonged dwell time as 7 months, where there is significant risk of standard technique failure, thereby requiring advanced techniques to maintain a high rate of technical success. Knowledge of this inflection point may be particularly useful in guiding referral of patients to centers with expertise in advanced retrieval techniques, where [retrievable inferior vena cava filters] with extended implantation times can be safely removed. As data on the potential risks of prolonged dwell [retrievable inferior vena cava filters] continue to mount, it is important to optimize opportunities to remove [inferior vena cava filters] that are no longer indicated,” the researchers wrote. – by Melissa Foster
Disclosures: Desai reports being on the speakers bureau for Cook Medical. Another researcher reports paid consulting for Spectranetics.