An Experimental Study On Material Properties Of The Novel Embolic Microspheres

1. An experimental comparison study on the suspension performance of the novel embolic microspheres.Objective: To investigate the suspension performance of the novel embolic microspheres and judge their quality.Methods: The novel embolic microspheres were defined as the experimental group, while the Boston Scientific Contour SE embolic microspheres as the control group. These two kinds of microspheres with the same size were well mixed with the contrast medium in the proportion of 2:6. The mixture was then turn into the 50 ml basic burette. Turned it over and kept it being vertical. Determined the settling time of these two kinds of microspheres and repeated 10 times. Compared their average settling time.Results: The average settling time of the novel embolic microspheres was 12 min 03 s, while the Boston Scientific Contour SE embolic microspheres was 11 min 53 s. There was no significant difference in their suspension performance (P>0.05).Conclusions: The suspension performance of the novel embolic microspheres is similar to the Boston Scientific Contour SE embolic microspheres.2. An experimental study on effects of hepatic artery embolization with the novel embolic microspheres.Objective: To investigate the effects of hepatic artery embolization using the novel embolic microspheres as embolic material of blood vessels.Methods: Twelve New Zealand adult healthy rabbits were randomly assigned into two groups defined as the experimental group and the control group using the novel embolic microspheres (100~300μm) and the Boston Scientific Contour SE embolic microspheres (100~300μm), respectively. Then they were treated by hepatic artery embolization.Behaviour and death of animals were documented during the whole experimental progress. On the 1st, 7th and 28th day, two randomly selected rabbits from each group were taken hepatic CT scanning and DSA to display the effects of hepatic artery embolization. The blood biochemistry including liver function was checked simultaneously. After sacrificing these rabbits, the tissues of their liver were obtained for comparing their gross anatomy, pathological changes and electron microscopy analysis.Results: DSA after hepatic artery embolization indicated that both the novel embolic microspheres and Boston Scientific Contour SE embolic microspheres blocked the target vessel better and resulted in target vessel occlusion and partial necrosis of the liver tissue. No significant differences were observed in blood biochemistry and liver morphological changes between these two groups.Histopathological examination revealed that no significant pathological changes in the vessels between the two kinds of embolic microspheres. The ultrastructure showed normal liver cell structure, the non-specific changes in cell.Conclusions: The novel embolic microspheres have better compatibility of biological tissue and similar effects of embolization with Boston Scientific Contour SE embolic microspheres. The novel embolic microspheres are an ideal vascular embolization material.3. An experimental study on effects of partial splenic embolization with the novel embolic microspheres.Objective: To research the effects of partial splenic embolization (PSE) using the novel embolic microspheres as embolic material of blood vessels.Methods: Twelve adult healthy Beagle dogs were randomly assigned into two groups defined as the experimental group and the control group using the novel embolic microspheres (500~700μm) and the Boston Scientific Contour SE embolic microspheres (500~700μm), respectively. Then they were treated by PSE.Behaviour and death of animals were documented during the whole experimental progress. On the 1st, 7th and 28th day, two randomly selected Beagle dogs from each group were taken splenic CT scanning and DSA to display the effects of partial splenic embolization. The blood biochemistry including Amylase and liver function was checked simultaneously. After sacrificing these dogs, the tissues of their splenic were obtained for comparing their gross anatomy, pathological changes and electron microscopy analysis.Results: Before partial splenic embolization, the digital substraction angiographic images of splenic artery showed clear delineation. Two agents resulted in target vessel occlusion and end-organ infarction. The blood routine had not perceivable difference in the two groups (P>0.05), but the hepatic function had (P<0.05). The vessels around the particles had not shown obvious pathological changes. The electron microscopic examination revealed that there was some cell degeneration in infarct district of spleen.Conclusions: The novel embolic microspheres can be made smooth through the micro-catheter and will not cause catheter obstruction. The artery of non-target organ wasn't embolized mistakenly. The novel embolic microspheres have better compatibility of biological tissue and similar effects of embolization with Boston Scientific Contour SE embolic microspheres. The novel embolic microspheres are an ideal vascular embolization material.