An Experimental Study of Early-Degradable Fish-Derived Spherical Gelatin Microparticles as an Embolic Agent in a Rabbit Renal Model

Objectives: To compare the degradation periods of different molecular weight (MW) fish-derived spherical gelatin microparticles (GMPs) via transauricular arterial access in a rabbit model. Methods: Twenty-four rabbits, weighing 2.7–3.8 kg, were used in the study. Renal angiography was performed with a microcatheter via transauricular approach. Segmental renal arteries were embolized using two different MW spherical GMPs (155–350 μm; low MW: 5–15 kDa; high MW: 15–30 kDa). In each group, rabbits were sacrificed immediately after embolization and were sacrificed after follow-up angiogram on day 2 and 21 of embolization, respectively. Degradation of the GMP and pathological changes were evaluated. For in vitro study, each GMP was mixed with saline and placed in a 37°C thermostat. Macroscopic and microscopic morphological changes of GMPs were compared for 2 weeks. Results: Both high and low MW spherical GMPs showed effective embolic results. On 2-day follow-up angiography, vessels were slightly recanalized to a similar degree. However, in low MW group, embolized arteries were reperfused to a greater extent on day 21, compared to the high MW GMP. Histologically, perivascular inflammation and fibrosis were more frequently identified in high MW group. In in vitro study, low MW GMP lost the spherical shape and degraded on day 5 and was invisible on microscopy, whereas high MW GMP was only partially degraded after 2 weeks. Conclusion: Low MW fish-derived spherical GMP revealed short-term embolic effect and provided early recanalization of the occluded arteries with low inflammatory response.

Publication History

Article published online:
26 April 2021