Experimental study on embolization of rabbit renal artery with gelatin sponge microspheres

The objective of this study was to evaluate the degradation characteristics and embolic effect of gelatin microspheres (GMSs) produced domestically in China through an experimental study comparing the embolization of rabbit renal arteries using GMSs and tris-acryl microspheres.

Sixteen healthy adult New Zealand white rabbits were randomly divided into two groups. Group A was embolized with GMSs produced in China with a diameter of 150-200 μm (n = 8), and Group B was embolized with tris-acryl microspheres with a diameter of 100-200 μm (n = 8). The renal arteries were embolized through femoral artery puncture and catheterization. Renal artery angiography rechecks and hematoxylin and eosin staining of tissue sections were performed at 1 day, 4 days, 7 days, and 14 days after embolization, respectively, to observe vascular recanalization, degradation of microspheres, and embolic effect.

Group A: Digital subtraction angiography showed complete recanalization at 14 days. The changes in embolic necrotic areas at different time points after embolization were similar in the two groups. At 4 days after embolization, changes in glomerular structure were observed in the kidney on the embolic side. At 7 days after embolization, atrophy, degeneration, and necrosis of the glomeruli, as well as degeneration and inflammatory cell infiltration of the renal tubules, were observed in the kidney on the embolic side. At 14 days after embolization, extensive atrophy and hyalinization of the glomeruli were observed, and local renal tissue showed patchy fibrosis with calcification of internal tissue. Hyperplasia of fibrillar connective tissue was observed in the renal interstitium.

The GMSs produced domestically in China can be completely degraded after embolizing blood vessels for 14 days. The GMSs are similar to tris-acryl microspheres in arterial embolization effect and are safe and effective.