Angiographic and histopathologic comparison of the embolic agents used in the transarterial embolization in a rabbit kidney model

AIM OF THE STUDY In this study, we compared the embolic efficiencies of polyvinyl particles (PVA), PVA microspheres (PVAS), collagen coated tris-acryl gelatin microspheres (Embosphere®, EM) and expanding tris-acryl gelatin microspheres (Quadrasphere®,QS) in a rabbit kidney model. METHOD 16 New Zealand rabbits were divided into four groups composed of four rabbits for each embolic agent. Right renal artery was embolized by using PVA (150-250?m), PVAS (150-300?m), EM (100-300?m) and QS (50-100?m). Two weeks after the embolizations, angiographic controls were done to evaluate the recanalization and infarct and then animals were sacrified. Pathologic specimens from harvested right kidneys were evaluated for the embolization level, vessel wall injury, extravasation, perivascular inflammation and neocapillarisation and infarct volumes were compared for every embolic agent. RESULTS While PVA particles were aggregating in the proximal levels microspheres tend to reach to more distal levels. Ekstravazation was seen in 50% of the PVA group, 25% of the PVAS group and 75% of the QS group but there was no extravasation within the kidneys embolized with EM. Highest degree of perivascular inflammation was found in the Quadrasphere® group. When we compared the embolic agents regarding on the infarct volumes we found out that Quadrasphere® resulted statistically less infarct than the other embolic agents. Largest infarct volumes were detected in the kidneys embolized with Embosphere®. Control angiographies showed recanalizations in all the kidneys of QS and PVAS groups while no recanalization was seen in the other two groups. CONCLUSION Quadrasphere® is less efficient regarding the volume of infarct when compared with the other embolic agents in the rabbit kidney model. Most efficient embolization was seen in the kidneys embolized with Embosphere®.