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M A Aller

Publications and source records attributed to M A Aller.

46 records · Page 3Linked to original sources
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A 70% hepatectomy in the rat using a microsurgical technique.

An experimental model of 70% hepatectomy in the rat using a microsurgical technique is described. An operative microscope (Carl Zeiss 10x2) dissection made it possible to identify the hilar anatomical variations and then to avoid unexpected damage to the arterio-portal and biliary branches belonging to the remaining hepatic parenchyma. The use of this microsurgical technique allows for a more homogenous experimental model because it avoids the functional impairment of the remaining liver.

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Progressive hepatocytic fatty infiltration in rats with prehepatic portal hypertension.

BACKGROUND/AIMS: Homogenous evolution, with a narrow range of portal hypertension, degree of portosystemic shunt and hepatic atrophy has been described in the experimental model of prehepatic portal hypertension in the rat. However the great differences observed in the rats' liver weight could be attributed to a pathological alteration of the liver. Based on this, we performed an evolutive histological study of the liver. This study shows the existence of a progressive hepatocytic fatty infiltration. METHODOLOGY: Male Wistar rats with portal hypertension induced by triple stenosing ligation of the portal vein at 1 month (group II, n=4) and at 1 year (group IV, n=10) of postoperative evolution were used. The portal pressure, body, liver and splenic weights, types of collateral circulation and degree of mesenteric venous congestion were studied. The intracytoplasmatic lipid microvacuoles were quantified in hepatocytes with an image analyzer (software MIP/CID, Spain). The results were compared with those obtained in control rats with the same evolutive periods (Groups I and III). RESULTS: The hepatic fatty infiltration in Group II (TPVS 1 month) (30.12+/-53.92 micron2) is similar to that presented by Group III (Control 1 year) (16.52+/-45.20 micron2), while there is an increase (p<0.001) in Group IV (triple portal vein stenosis 1 year) (182.03+/-371.42 micron2) in relation to the other groups studied. The progressive hepatic fatty infiltration in triple portal vein stenosis rats is associated with a decrease of portal pressure and of the incidence of liver hepatic atrophy, portosystemic collateral circulation and mesenteric venous congestion. CONCLUSIONS: TPVS produces progressive hepatocytic fatty infiltration in the rat so that this prehepatic portal hypertension experimental model could also be considered as a hepatic steatosis model.

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Washout of the pig liver with Haemaccel after hypothermic preservation.

In hepatic preservation by simple perfusion and hypothermic storage, a portal and hepatic washout before revascularization would avoid receptor hyperkaliema. In this report we study the effectiveness of this washout with Haemaccel at room temperature. Large-White pigs were used and eight livers were perfused "in situ" via the portal wein with Hartmann's solution containing 10,000 IU of heparin at 4 degrees C, and afterwards, via portal and arterial routes with C2 solution at 4 degrees C. After a cold ischemia time of less than 31/2 hours a liver washout via the portal vein and hepatic artery with Haemaccel before portal revascularization was done. The high concentrations of glucose, K+, GOT, GPT and LDH in the effluents obtained during the washout are attributed to Haemaccel hyperosmolarity. A portal and arterial hepatic washout associated with free drainage of the first 50-100 ml of portal venous blood after hepatic portal revascularization through the infrahepatic inferior vena cava (IH-IVC), prevents hyperkaliemia from occurring after a portal and arterial revascularization in the orthotopic liver transplant (OLT) in pigs.

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PubMedDate not supplied

Portal and arterial washout after hypothermic preservation of the pig liver: prevention of hyperkalaemia after revascularization.

In an orthotopic liver transplantation (OLT), portal revascularization may produce acidosis and hyperkalaemia due to loss of intracellular acid metabolites and K+ during hypothermic preservation. To verify the effectiveness of portal and arterial washout in preventing hypokalaemia after liver preservation, an OLT was done in 18 large-white pigs. The donor livers were perfused in situ via the portal vein with Hartmann's solution containing 1.000 IU of heparin at 4 degrees C. Afterwards, a cold Collins C2 solution was perfused either in vitro (group A) or in situ (group B). The cold ischemia time in both groups was less than 3 1/2 h. Before doing the portal revascularization of the donor livers, a washout via the portal vein and hepatic artery with saline serum was performed. The concentration of K+, glucose, GOT and LDH in effluents obtained through infrahepatic inferior vena cava were significantly lower in group B than in group A. Simple washout of the livers prior to revascularization prevented hyperkalaemia in both groups.

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PubMedDate not supplied

Changes in serum insulin levels during orthotopic liver transplantation in the pig.

Insulin and glucose levels were measured in 13 orthotopic liver transplantations in pigs. After portal revascularization a significant increase in the glucose levels takes place (p less than 0.01). When the infrahepatic vena cava clamp is removed, a significant increase in glucose and insulin concentrations (p less than 0.05) takes place. After the end of the operation the insulin levels decrease significantly with respect to initial values (p less than 0.05).

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PubMedDate not supplied

Auxiliary liver transplantation in the pig without portal blood: a study of a new technique for application to the heterotopic hepatic xenotransplant.

An auxiliary liver transplantation surgical technique in the pig, in which the graft only receives blood flow via the hepatic artery since an end-to-side portacaval shunt is performed in the donor animal prior to the transplantation, is described. The functional impairment of the receptor liver was done by a ligature of the choledoch, provoking death by sepsis in six of the transplanted animals at 8.16 +/- 6.61 days post transplantation. The auxiliary liver never suffered atrophy and prevented jaundice. It can be concluded that this simple surgical technique could be applied to the heterotopic xenotransplantation when the complications inherent in the immunological aggression are eliminated.

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