Abstract No. 670 Optimal delivery rate and concentration of radiopaque beads for trans-arterial embolization

Abstract

To determine how changes in the standard injection rate (1.0 mL/min), in the standard concentration (1:9), or the size of the LUMI beads affect the embolization volume. A total of 9 Yorkshire pigs underwent fluoroscopy guided injection of LUMI radiopaque beads using 2 different LUMI bead sizes (R0=40-90 and R1=70-150 microns). Each animal was injected with 1 of 3 bead / Visipaque 320 contrast concentrations (1:4, 1:9, and 1:14) and at 1 of 3 injection rates (0.5mL/min, 1.0mL/min, and 1.5mL/min). Isovue contrast was used to position the catheter and allow for direct injection of the embolization beads into the arterial branch of the liver and kidneys. The larger LUMI beads (70-150 microns) were used to embolize the left kidneys and left hepatic lobes and the smaller LUMI beads (40-90 microns) were used to embolize the right kidneys and right hepatic lobes. The animals were subsequently euthanized. The distance of the beads from the hilum was then evaluated with imaging and pathological correlation. Technical success rate was 100% (36/36). Embolization was achieved regardless of the injection rate and concentration. The complication rate after the embolization process was 0% (0/36). When measuring the effect of concentration on embolization volume, higher concentrations correlated with decreased embolization volumes in both the liver and kidney (P = .018 and P = .001, respectively). Smaller bead sizes also correlated with decreased embolization volume in both the liver and kidney (P = .014 and P = .048, respectively). However, different injection rates did not result in a statistically significant difference in embolization volume in either the liver or kidney (P = .393 and P = .338, respectively). Increased concentration and smaller bead sizes appear to decrease embolization volume. However, changes in the injection rate do not appear to affect the embolization volume.