Attempted induction of chronic portal venous hypertension with polyvinyl alcohol particles in swine.
OBJECTIVE
Creation of presinusoidal chronic portal venous hypertension by means of repeated portal vein (PV) embolization was explored in an attempt to improve a porcine model of transjugular intrahepatic portosystemic shunt (TIPS) patency.


METHODS
Six microswine underwent weekly PV embolization for 5 weeks with a total of 10.4-12.6 g of polyvinyl alcohol (PVA) particles (0.149-0.250 mm in size). Portography, liver function tests, pressure measurement in the PV and inferior vena cava (IVC) before and after PV embolization, and histopathologic evaluation of the livers were performed.


RESULTS
Transhepatic portal venography performed after each embolization demonstrated diffuse PV branch occlusion in all cases. At weekly follow-up, reconstitution of flow was demonstrated in these branches; permanent occlusion of PV branches was not achieved. The mean PV pressure elevated acutely from 17.3 mm Hg +/- 0.9 to 24.5 mm Hg +/- 4.2 (P < .01) after each embolization. However, the pressure always returned to baseline on the follow-up studies 1 week later. Liver function tests were normal. Histopathologic evaluation of the liver showed, in multiple PV branches, central plugs of PVA with peripheral recanalization. The liver parenchyma was otherwise normal.


CONCLUSIONS
Massive embolizations of PV with PVA at weekly intervals failed to create permanent portal hypertension or induce hepatic fibrosis.
Pavcnik
D
D
Dotter Interventional Institute, Oregon Health Sciences University, Portland 97201, USA.
Saxon
R R
RR
Kubota
Y
Y
Tanihata
H
H
Uchida
B T
BT
Corless
C
C
Keller
F S
FS
D000818:Animals; D001794:Blood Pressure; D002908:Chronic Disease; D004195:Disease Models, Animal; D004617:Embolism / Q000139:chemically induced* / Q000150:complications / Q000473:pathology; D005500:Follow-Up Studies; D006975:Hypertension, Portal / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D008111:Liver Function Tests; D011142:Polyvinyl Alcohol / Q000633:toxicity*; D011169:Portal Vein / Q000187:drug effects*; D019168:Portasystemic Shunt, Transjugular Intrahepatic; D011172:Portography; D013552:Swine; D013556:Swine, Miniature
D011142:Polyvinyl Alcohol