title: Gelatin microspheres: correlation between embolic effect/degradability and cross-linkage/particle size.
abstract: OBJECTIVE
  To evaluate the embolic effect and degradability of gelatin microspheres (GMS) using various degrees of cross-linkage and particle sizes in rabbit renal artery embolization.
  
  
  METHODS
  Four types of GMS were used, as follows: 2 types of cross-linkage and 2 types of particle size. Twenty-four rabbits (6 in each group) were used for the renal artery embolization. Renal angiography was performed before and after embolization of right renal artery. Follow-up renal angiography was performed 2 days (n = 2), 5 days (n = 2), and 15 days (n = 2) after embolization in each group, and then kidneys were removed for histopathological evaluation. Vascular areas of the angiography were measured by Image J software, and the reperfusion rate was calculated. In renal specimens, residual GMS were checked and the degree of degradation was classified according to a 4-point scale.
  
  
  RESULTS
  The mean amounts of large- and small-particle-size GMS injected were 15.0 and 34.3 mg, respectively. Tissue necrosis was confirmed in each group; however, no difference was observed among groups. Renal reperfusion was observed more with small GMS than with large GMS. Renal reperfusion was also observed more with low cross-linked GMS than with high cross-linked GMS. In histopathological specimens, large GMS were confirmed in lobar artery, and small GMS were confirmed in lobular artery. Low cross-linked GMS completely degraded 15 days after embolization. In contrast, high cross-linked GMS were persistent 15 days after embolization.
  
  
  CONCLUSIONS
  Degree of cross-linkage and particle size affected degradability and reperfusion.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu City, Shiga, 520-2192, Japan. junryuhei@yahoo.co.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohta
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.forename: Shobu
authors.initials: S
authors.lastname: Watanabe
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tomozawa
authors.forename: Akinaga
authors.initials: A
authors.lastname: Sonoda
authors.forename: Hideji
authors.initials: H
authors.lastname: Otani
authors.forename: Keiko
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Ayumi
authors.initials: A
authors.lastname: Nitta-Seko
authors.forename: Atsuko
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000792:Angiography / Q000379:methods; D000818:Animals; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005780:Gelatin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D007150:Immunohistochemistry; D007668:Kidney / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D008297:Male; D008863:Microspheres; D010316:Particle Size; D011817:Rabbits; D011897:Random Allocation; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D005780:Gelatin