Portal hyperperfusion causes disturbance of microcirculation and increased rate of hepatocellular apoptosis: investigations in heterotopic rat liver transplantation with portal vein arterialization.
Clinical results of portal vein arterialization (PVA) in liver transplantation are controversial. One reason for this is the lack of a standardized flow regulation. Our experiments in rats compared PVA with blood-flow regulation to PVA with hyperperfusion in heterotopic auxiliary liver transplantation (HALT). In group I (n = 19), the graft's portal vein was completely arterialized via the right renal artery in-stent technique, using a 0.3-mm stent, leading to a physiological average portal blood flow. In group II (n = 19), a 0.5-mm stent was used. In group II, the average portal blood flow after reperfusion was significantly elevated (group II: 6.4 +/- 1.5; group I: 1.7 +/- 0.4 mL/min/g of liver weight; P < .001). The sinusoidal diameter after reperfusion was significantly greater in group II (9.8 +/- 0.5 microm) than in group I (5.5 +/- 0.2 microm; P < .001). Red blood cell velocity in the dilated sinusoids was significantly lower in group II (171 +/- 18 microm/s) than in group I (252 +/- 13 microm/s). Stasis of erythrocytes occurred; consequently, the functional sinusoidal density was significantly reduced in group II (38 +/- 7%) compared with group I (50 +/- 3%; P < .01). Two hours after reperfusion of the portal vein, the number of apoptotic hepatocytes was significantly higher in group II than in group I (I: 0 +/- 0 vs II: 7 +/- 9 M30-positive hepatocytes/10 high-power fields). The 6-week survival rate was 9 of 11 in both groups. In group II, 6 of 9 grafts showed massive hepatocellular necroses after 6 weeks, whereas in group I, only 1 of 9 presented a slight hepatocellular necrosis. Finally, our results demonstrate negative effects of portal hyperperfusion in transplanted livers, which are correctable by adequate flow regulation.
Schleimer
K
K
Department of Visceral, University of Cologne, Cologne, Germany. Karina.Schleimer@medizin.uni-koeln.de
Stippel
D L
DL
Kasper
H-U
HU
Tawadros
S
S
Allwissner
R
R
Gaudig
C
C
Greiner
T
T
Hölscher
A H
AH
Beckurts
K T E
KT
D000818:Animals; D017209:Apoptosis; D008099:Liver / Q000473:pathology*; D016031:Liver Transplantation / Q000379:methods* / Q000473:pathology*; D008297:Male; D008833:Microcirculation / Q000473:pathology*; D023421:Models, Animal; D011169:Portal Vein / Q000601:surgery*; D011183:Postoperative Complications / Q000473:pathology*; D051381:Rats; D011917:Rats, Inbred Lew; D015607:Stents; D016042:Transplantation, Heterotopic