OBJECTIVE:  Evaluate the embolization effectiveness, visibility and degradability of embolic radiopaque glass microspheres (ERGM) in swine renal artery, as well as the recanalization of the embolized vessels.

METHODS:  Bilateral caudal renal artery embolization was conducted in 4 non-diseased pigs.  Three of them received ERGM (100-300 μm) and one received Bead Blocks® (control). Imaging assessment was performed using Fluoroscopy Shoot, DSA, C-arm CT and histology at three different time points: 0h, 24h, 48h.

RESULTS: Visualization of glass beads was possible on all imaging methods, however use of contrast was necessary to have a better embolization monitoring on fluoroscopy. The total time of the procedure was slightly longer for the tested particles (average 84 min) compared to the control (55 min). The volume of particles injected was higher for control, 1,5g versus 0,8g for tested. The volume of remaining degradable particles was clearly smaller over the time: 0h (100%), 24h (2%) and 48h (1,9%). The CBCT was able to visualize the particles with good resolution, being possible to verify the degradation progression of the glass microspheres over the time.  The DSA was able to demonstrate the onset of vessel recanalization even just 24h and 48h after the procedure, which was confirmed by histology.

CONCLUSION: the ERGM have an excellent degradable capacity in an ideal average interval of 48 hours, without any impairment in the effectiveness of the embolization. The recanalization could be visualized even after a short period of time.

DEGRADABLE RADIOPAQUE EMBOLIC GLASS MICROSPHERES: PRE-CLINICAL EVALUATION ON IMAGING AND HISTOLOGY