[The impact of selective clamping of portal vein in hepatocellular function. An experimental study].
The influence of selective clamping of the elements of hepatic pedicle in the hepatocellular function and viability were evaluated in our department.


OBJECTIVE
Study the effect of selective clamping of the portal vein (CPV) in hepatocellular function in an animal model with normal liver.


METHODS
Three groups of Wistar rats (males, 2 months) were subjected a CPV for 60 min: group A (n=21) submitted to a continuous inflow occlusion; group B (n=12) underwent to a CPV for 30 min with 5 min of reperfusion; group C (n=10) underwent a CPV for 15 min with 5 min of reperfusion. The group D (n=9) was not subjected to a CPV. A hepatic biopsy was done at the end of surgery. The degree of tissue injury was evaluated using: 1) blood markers: AST, ALT, total bilirubin (TB), GGT alkaline-phosphatase, LDH and hepatic extraction fraction (HEF) by radioisotopic methods three days before laparotomy (BS) and after surgery (AS); 2) apoptosis, necrosis were investigated after collagenase cell isolation from hepatectomy pieces by flow-cytometry using the followed probes: propidium-iodide and annexin-V.


METHODS
variance analysis, post-hoc comparisons by Turkey-test (p<0.05).


RESULTS
1) Mortality: Group A - 62%, Group B - 17%, Group C - 30%, Group D - 0% (p<0.03). 2) We observed statistical differences in these parameters: ALT (p<0,025) and LDH (p<0,002) preferentially in groups A but without differences between the A,B,C and D Groups (ns). 3) We also verified a significant decrease in HEF values (p<0,0001) preferentially in group A without differences between the groups. 4) No difference were observed when analysed apoptosis and necrosis and cell viability between the groups.


CONCLUSIONS
Postoperative liver failure is the leading cause of mortality after hepatectomy, however selective clamping of the portal vein, is reflected in an increase in cell viability and a decrease in the type of cell death (necrosis ou apoptosis) compared to studies carried out previously by us and thus may be regarded as an alternative to the Pringle maneuver. However, selective clamping of the portal vein for periods above 30' should be avoided, given the high mortality verified.
Departamento de Cirurgia, Serviços de Clínica Cirúrgica e Cirurgia III, Instituto de Biofísica e Biomatemática, Universidade de Coimbra.
J Guilherme
JG
Tralhão
Ana M
AM
Abrantes
Cristina
C
Gonçalves
César
C
Carvalho
Ivan
I
Portela
Mafalda
M
Laranjo
Bárbara
B
Oliveiros
Dulce
D
Cardoso
Ana Bela Sarmento
AB
Ribeiro
F Castro
FC
Sousa
D000818:Animals; D003250:Constriction; D022781:Hepatocytes / Q000502:physiology*; D008099:Liver / Q000098:blood supply*; D008297:Male; D011169:Portal Vein; D051381:Rats; D017208:Rats, Wistar