Experimental Evaluation of Early and Long-Term Effects of Microparticle Embolization in Two Different Mini-Pig Models. Part I: Kidney

Journal Article · Sun Apr 15 04:00:00 EDT 2007 · Cardiovascular and Interventional Radiology

DOI:https://doi.org/10.1007/S00270-005-0309-4· OSTI ID:21091036

Stampfl, S; Stampfl, U; Rehnitz, C ^[1]; Schnabel, Ph ^[2]; Satzl, S; Christoph, P; Henn, C ^[1]; Thomas, F ^[3]; Kauffmann, G W

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1. University of Heidelberg, Department of Diagnostic Radiology (Germany)
2. University of Heidelberg, Department of General Pathology (Germany)
3. University of Heidelberg, Department of Vascular Surgery (Germany)

Purpose. Using a pig model: (1) to evaluate the vascular distribution pattern, including the homogeneity and completeness of the intra-arterial microsphere distribution, of 40-120-{mu}m trisacryl-gelatin microspheres (Embospheres) in acute whole-kidney embolization; (2) to evaluate the durability and biocompatibility of 40-120-{mu}m trisacryl-gelatin microspheres (Embospheres) in chronic partial kidney embolization. Methods. Twenty-two animals were divided into four groups: group 1 (n = 4) underwent total arterial renal occlusion with immediate euthanasia. Groups 2-4 had chronic superselective and partial renal embolization with increasing follow-up times: group 2 (n = 2), 1 week; group 3 (n = 7), 4 weeks; and group 4 (n = 9), 14 weeks. Key endpoints in group 1 were homogeneity and completeness of acute embolizations. In groups 2-4 the key endpoints were durability of embolization and particle-related inflammation in chronic partial embolizations as assessed by quantitative angiography or histomorphometry. A numerical angiographic occlusion score (0.0 to 4.0, where 3.0 is optimal) was developed to assess and quantify the angiographic durability of superselective embolizations (groups 2-4). Results. In group 1, a relatively homogeneous distribution of the particles from segmental arteries to the precapillary level was shown by histomorphometry. Some particles reached the glomerular vas afferens (10 {mu}m diameter). In groups 2-4, a mild recanalization appeared during follow-up. The immediate average postembolization occlusion score of 3.18 {+-} 0.73 was reduced to 1.44 {+-} 0.73 (statistically significant). Microscopy revealed subtotal necrosis but no foreign body granuloma formation. The intra-arterial appearance of giant cells closely attaching to the surface of the embolic spheres inside the vessel lumen was noted. Vessel walls showed major ischemic reactions. Conclusion. Microspheres 40-120 {mu}m in diameter might achieve total occlusion of the arterial kidney vasculature when injected centrally as a result of their fairly homogeneous distribution. Segmental renal infarction occurs after chronic partial embolization despite recanalizations during follow-up. Only mild specific intra-arterial foreign body reactions were found.

• OSTI ID: 21091036
• Journal Information: Cardiovascular and Interventional Radiology, Journal Name: Cardiovascular and Interventional Radiology Journal Issue: 2 Vol. 30; ISSN 0174-1551; ISSN CAIRDG
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ARTERIES
BIOMEDICAL RADIOGRAPHY
GELATIN
INFLAMMATION
KIDNEYS
MICROSCOPY
MICROSPHERES
NECROSIS
SWINE
TUMOR CELLS