University of Colorado, USA
Robert Ryu is a Professor of Radiology and Director of Interventional Radiology at the University of Colorado Anschutz Medical Campus in Denver, CO. He is a Fellow of the Society of Interventional Radiology. He was the Radiology Residency program Director at Northwestern University from 2005-2014, where he was Cofounder of the IVC Filter clinic. He has authored over 100 peer reviewed publications. His areas of clinical and research interests include venous thrombo-embolic disease, interventional oncology and hepatobiliary intervention.
Purpose: Decreased successful retrieval rates have been reported in conjunction with prolonged dwell time of retrievable IVC fi lters (rIVCF). Th e use of adjunctive techniques has improved overall retrieval rates of these devices. Th is study compares the technical successful retrieval rate of rIVCF with prolonged dwell time (defi ned as >6 months), with rIVCF implanted for <6 months. We hypothesize that the technical success rate of rIVCF retrieval is equivalent. We aim to determine and compare technical and clinical factors that impact retrieval success in both cohorts. Materials: All rIVCF retrieval procedures from Jan 2009 to Dec 2014 were identifi ed from a prospectively acquired database. We assessed the technical success of rIVCF retrieval; we recorded fi lter dwell time as <6 months or >6 months for all cases. Th e use of adjunctive retrieval techniques was also recorded. Adjunctive techniques included loop wire, directional sheath use, balloon disruption, endo-bronchial forceps and excimer laser assistance. Statistics were analyzed using the Chi square test, with signifi cance accepted at p<0.05. Results: During the study period, 648 rIVCF retrieval procedures were performed. Th e technical success rate for retrieval procedures performed with rIVCFs in place <6 months was 97.7% (n=596); retrieval technical success rate for rIVCFs in place >6 months was 94.2% (n=52) (p=0.14). Adjunctive techniques were necessary to remove rIVCFs with <6 months dwell time 11% of the time (n=62), and 67% of the time (n=33) for rIVCFs with >6 months dwell time (p<0.001). Overall, complications occurred in 3% (3 major, 15 minor). Conclusions: Th ere is no signifi cant diff erence in the technical success rate for removal of rIVCFs that were implanted >6 months vs. <6 months ago. Retrieval rates for both cohorts exceeded 94%. In patients with prolonged IVC fi lter dwell time, adjunctive techniques are used more frequently to achieve these results.