Experimental evaluation of early and long-term effects of microparticle embolization in two different mini-pig models. Part II: liver.
OBJECTIVE
To evaluate trisacryl-gelatin microspheres (40-120 microm) for acute and chronic tissue embolization in mini-pig livers.


METHODS
Thirteen animals were divided into four groups: group 1 (n = 3), total arterial bed occlusion with acute procedure; groups 2 to 4, chronic superselective embolization with follow-up of 1 week (group 2, n = 1), 4 weeks (group 3, n = 4) or 14 weeks (group 4, n = 5). Key endpoints were homogeneity and particle distribution in acute embolizations (group 1) and necrosis and inflammation in chronic embolizations (groups 2-4) as assessed microscopically and angiographically.


RESULTS
After liver embolization, parenchymal necrosis did not occur; only signs of vessel wall disintegration were evident. The bile ducts remained intact. A distinct foreign body reaction with sparse leukocytic infiltration and giant cells was found at 14 weeks, but no signs of major inflammation were found. Particles were seen at the presinusoidal level, but no particle transportation into the sinusoids was observed.


CONCLUSIONS
Embolization in mini-pig livers, using small trisacryl-gelatin microspheres, results in vessel fibrosis without parenchymal or bile duct necrosis. The most likely explanation for preservation of the parenchyma is portal inflow. Small trisacryl-gelatin microspheres may be ideal as an adjunct for chemoembolization.
Stampfl
S
S
Department of Diagnostic Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany.
Stampfl
U
U
Rehnitz
C
C
Schnabel
Ph
P
Satzl
S
S
Christoph
P
P
Henn
C
C
Thomas
F
F
Richter
G M
GM
D000180:Acrylic Resins / Q000009:adverse effects / Q000627:therapeutic use*; D000818:Animals; D004621:Embolization, Therapeutic / Q000379:methods*; D005548:Foreign-Body Migration / Q000473:pathology; D005549:Foreign-Body Reaction / Q000473:pathology; D005780:Gelatin / Q000009:adverse effects / Q000627:therapeutic use*; D006499:Hepatic Artery / Q000473:pathology; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D013552:Swine; D013556:Swine, Miniature
D000180:Acrylic Resins; C496735:trisacryl gelatin microspheres; D005780:Gelatin