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Degradable gelatin microspheres as an embolic agent: an experimental study in a rabbit renal model.

Ohta S, Nitta N, Takahashi M, Murata K, Tabata Y - Korean J Radiol (2007 Sep-Oct)

Bottom Line: On days 3, 7, and 14, parenchymal infarctions were observed histologically in all cases, and this observation corresponded with the parenchyma being supplied by the embolized arteries.GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries.In all but two cases, the GMSs were identified histologically even on day 14, and sequential degradation was histologically identified in all GMS groups.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Shiga University of Medical Science, Shiga, Japan. junryuhei@belle.shiga-med.ac.jp

ABSTRACT

Objective: To investigate the basic characteristics of degradable gelatin microspheres (GMSs), including their embolic behavior and degradation periods when they are used as embolic materials in the renal arteries of rabbit models.

Materials and methods: Based on the GMS particle size, 24 kidneys were divided into 3 groups of eight kidneys, and each group was embolized with a different GMS particle size (group 1: 35-100 microm, group 2: 100-200 microm, and group 3: 200-300 microm). From each group, two rabbits were sacrificed immediately after embolization (day 0), and a pair of rabbits from each group underwent an angiogram and were sacrificed on days 3, 7, and 14, respectively, after embolization. The level of arterial occlusion, the pathological changes in the renal parenchyma, and the degradation of the GMSs were evaluated angiographically and histologically.

Results: A follow-up angiogram on days 0, 3, 7, and 14 revealed the presence of wedge-shaped poorly-enhanced areas in the parenchymal phase as seen in all groups. The size of these areas tended to increase with the particle diameter, and persisted up to day 14. On days 3, 7, and 14, parenchymal infarctions were observed histologically in all cases, and this observation corresponded with the parenchyma being supplied by the embolized arteries. GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries. In all but two cases, the GMSs were identified histologically even on day 14, and sequential degradation was histologically identified in all GMS groups.

Conclusion: GMSs can be used as degradable embolic materials which can control the level of embolization.

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Related in: MedlinePlus

Photomicrographic appearance of a resected kidney of group 1 (A) and group 3 (B) immediately after the embolic procedure. It was observed that the gelatin microspheres in group 1 frequently reached the interlobular arteries (arrow in A), while those of group 3 reached the interlobar arteries (arrow in B). (Hematoxylin & Eosin staining; original magnification, ×40)
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Figure 3: Photomicrographic appearance of a resected kidney of group 1 (A) and group 3 (B) immediately after the embolic procedure. It was observed that the gelatin microspheres in group 1 frequently reached the interlobular arteries (arrow in A), while those of group 3 reached the interlobar arteries (arrow in B). (Hematoxylin & Eosin staining; original magnification, ×40)

Mentions: The level of renal artery occlusion caused by the GMSs was identified based on the pathological specimens; these values and the sizes of the poorly-enhanced areas observed in the angiograms are summarized in Table 2. It was observed that immediately after embolization, the GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries (Fig. 3). However, on days 3, 7, and 14, the GMSs with larger diameters mainly occurred in the interlobular arteries. In group 1, agglutinated GMSs that blocked the vascular lumen occurred in the interlobar artery. On days 3, 7, and 14, parenchymal infarctions were observed in all cases; these infarctions corresponded to the feeding areas of the occluded arteries. Large infarctions were observed in the cases in which the central arteries were occluded, and these infarctions were observed on the angiogram as a large poorly-enhanced area.


Degradable gelatin microspheres as an embolic agent: an experimental study in a rabbit renal model.

Ohta S, Nitta N, Takahashi M, Murata K, Tabata Y - Korean J Radiol (2007 Sep-Oct)

Photomicrographic appearance of a resected kidney of group 1 (A) and group 3 (B) immediately after the embolic procedure. It was observed that the gelatin microspheres in group 1 frequently reached the interlobular arteries (arrow in A), while those of group 3 reached the interlobar arteries (arrow in B). (Hematoxylin & Eosin staining; original magnification, ×40)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2626815&req=5

Figure 3: Photomicrographic appearance of a resected kidney of group 1 (A) and group 3 (B) immediately after the embolic procedure. It was observed that the gelatin microspheres in group 1 frequently reached the interlobular arteries (arrow in A), while those of group 3 reached the interlobar arteries (arrow in B). (Hematoxylin & Eosin staining; original magnification, ×40)
Mentions: The level of renal artery occlusion caused by the GMSs was identified based on the pathological specimens; these values and the sizes of the poorly-enhanced areas observed in the angiograms are summarized in Table 2. It was observed that immediately after embolization, the GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries (Fig. 3). However, on days 3, 7, and 14, the GMSs with larger diameters mainly occurred in the interlobular arteries. In group 1, agglutinated GMSs that blocked the vascular lumen occurred in the interlobar artery. On days 3, 7, and 14, parenchymal infarctions were observed in all cases; these infarctions corresponded to the feeding areas of the occluded arteries. Large infarctions were observed in the cases in which the central arteries were occluded, and these infarctions were observed on the angiogram as a large poorly-enhanced area.

Bottom Line: On days 3, 7, and 14, parenchymal infarctions were observed histologically in all cases, and this observation corresponded with the parenchyma being supplied by the embolized arteries.GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries.In all but two cases, the GMSs were identified histologically even on day 14, and sequential degradation was histologically identified in all GMS groups.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Shiga University of Medical Science, Shiga, Japan. junryuhei@belle.shiga-med.ac.jp

ABSTRACT

Objective: To investigate the basic characteristics of degradable gelatin microspheres (GMSs), including their embolic behavior and degradation periods when they are used as embolic materials in the renal arteries of rabbit models.

Materials and methods: Based on the GMS particle size, 24 kidneys were divided into 3 groups of eight kidneys, and each group was embolized with a different GMS particle size (group 1: 35-100 microm, group 2: 100-200 microm, and group 3: 200-300 microm). From each group, two rabbits were sacrificed immediately after embolization (day 0), and a pair of rabbits from each group underwent an angiogram and were sacrificed on days 3, 7, and 14, respectively, after embolization. The level of arterial occlusion, the pathological changes in the renal parenchyma, and the degradation of the GMSs were evaluated angiographically and histologically.

Results: A follow-up angiogram on days 0, 3, 7, and 14 revealed the presence of wedge-shaped poorly-enhanced areas in the parenchymal phase as seen in all groups. The size of these areas tended to increase with the particle diameter, and persisted up to day 14. On days 3, 7, and 14, parenchymal infarctions were observed histologically in all cases, and this observation corresponded with the parenchyma being supplied by the embolized arteries. GMSs of group 1 mainly reached the interlobular arteries, while those of group 3 mainly reached the interlobar arteries. In all but two cases, the GMSs were identified histologically even on day 14, and sequential degradation was histologically identified in all GMS groups.

Conclusion: GMSs can be used as degradable embolic materials which can control the level of embolization.

Show MeSH
Related in: MedlinePlus