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Portal Vein Ligation (portal + vein_ligation)

Distribution by Scientific Domains
Medical Sciences100%

Kinds of Portal Vein Ligation

  • partial portal vein ligation
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    Selected Abstracts

    Hepatic arterial flow becomes the primary supply of sinusoids following partial portal vein ligation in rats

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2006
    Yukihiro Yokoyama
    Abstract Background and Aim:, Partial portal vein ligation (PPVL) is a commonly used procedure to induce prehepatic portal hypertension in animal models. The aim of this study was to test the hypothesis that the hepatic arterial flow becomes the primary source feeding the sinusoids in the liver after PPVL. Methods:, Sprague,Dawley rats underwent either sham operation or partial portal vein ligation (PPVL). The number of vessels in the liver at 2 weeks postoperatively was determined by factor VIII immunolocalization and the gene expression of angiogenic factors was assessed by RT-PCR. The total hepatic arterial supply to the liver was measured using the fluorescent microsphere injection technique. To further test the hypothesis, two additional groups of rats underwent hepatic artery ligation (HAL) or PPVL plus HAL (PPHAL). The integrity of hepatic microcirculation was then evaluated in all four groups by intravital microscopy. Results:, At 2 weeks after operation, the number of vessels detected by factor VIII staining was significantly higher in PPVL compared to sham. Densitometric analysis of RT-PCR bands revealed a significant increase of vascular endothelial growth factor gene expression in PPVL compared to sham. Arterial flow to the liver measured by fluorescent microspheres was increased by 190% in PPVL compared to sham. When all four groups were compared, no prominent histological abnormality was observed in sham, HAL, and PPVL groups; however, PPHAL livers showed focal necrosis and inflammatory cell infiltration around the portal triads. Additionally, only the PPHAL livers showed a decreased sinusoidal diameter and significantly lower perfusion index (PPHAL 42.9 ± 6.1; sham 85.7 ± 7.0, PPVL 80.2 ± 6.5, HAL 70.9 ± 4.5). Conclusions:, These results suggest that the hepatic artery flow becomes the primary source for the blood supply of sinusoids and the compensatory change in the hepatic arterial system plays a critical role in maintaining microcirculatory perfusion following the restriction of the portal vein flow by PPVL. [source]

    Measurement of porto-systemic shunting in mice by novel three-dimensional micro-single photon emission computed tomography imaging enabling longitudinal follow-up

    LIVER INTERNATIONAL, Issue 8 2010
    Christophe Van Steenkiste
    Abstract Background and aims: The reference method for diagnosing porto-systemic shunting (PSS) in experimental portal hypertension involves measuring 51Chrome (51Cr)-labelled microspheres. Unfortunately, this technique necessitates the sacrifice of animals. Alternatively, 99mtechnetium-macroaggregated albumin (99mTc-MAA) has been used; however, planar scintigraphy imaging techniques are not quantitatively accurate and adequate spatial information is not attained. Here, we describe a reliable, minimally invasive and rapid in vivo imaging technique, using three-dimensional single photon emission computed tomography (3D SPECT) modus, that allows more accurate quantification, serial measurements and spatial discrimination. Methodology: Partial portal vein ligation, common bile duct ligation and sham were induced in male mice. A mixture of 51Cr microspheres and 99mTc-macroaggregated albumin particles was injected into the splenic pulpa. All mice were scanned in vivo with ,SPECT (1 mm spatial resolution) and, when mandatory for localisation, a ,SPECT-CT was acquired. A relative quantitative analysis was performed based on the 3D reconstructed datasets. Additionally, 51Cr was measured in the same animals to calculate the correlation coefficient between the 99mTc detection and the gold standard 51Cr. In each measuring modality, the PSS fraction was calculated using the formula: [(lung counts)/(lung counts+liver counts)] × 100. Results: A significant correlation between the 99mTc detection and 51Cr was demonstrated in partial portal vein ligation, common bile duct ligation and sham mice and there was a good agreement between the two modalities. ,SPECT scanning delivers high spatial resolution and 3D image reconstructions. Conclusion: We have demonstrated that quantitative high-resolution ,SPECT imaging with 99mTc-MAA is useful for detecting the extent of PSS in a non-sacrificing set-up. This technology permits serial measurements and high-throughput screening to detect baseline PSS, which is especially important in pharmacological studies. [source]

    The value of microsurgery in liver research

    LIVER INTERNATIONAL, Issue 8 2009
    Maria-Angeles Aller
    Abstract The use of an operating microscope in rat liver surgery makes it possible to obtain new experimental models and improve the already existing macrosurgical models. Thus, microsurgery could be a very valuable technique to improve experimental models of hepatic insufficiency. In the current review, we present the microsurgical techniques most frequently used in the rat, such as the portacaval shunt, the extrahepatic biliary tract resection, partial and total hepatectomies and heterotopic and orthotopic liver transplantation. Hence, reducing surgical complications allows for perfecting the resulting experimental models. Thus, liver atrophy related to portacaval shunt, prehepatic portal hypertension secondary to partial portal vein ligation, cholestasis by resection of the extrahepatic biliary tract, hepatic regeneration after partial hepatectomies, acute liver failure associated with subtotal or total hepatectomy and finally complications derived from preservation or rejection in orthotopic and heterotopic liver transplantation can be studied in more standardized experimental models. The results obtained are therefore more reliable and facilitates the flow of knowledge from the bench to the bedside. Some of these microsurgical techniques, because of their simplicity, can be performed by researchers without any prior surgical training. Other more complex microsurgical techniques require in-depth surgical training. These techniques are ideal for achieving a complete surgical training and more select microsurgical models for hepatology research. [source]

    The effects of pentoxifylline on liver regeneration after portal vein ligation in rats

    LIVER INTERNATIONAL, Issue 2 2007
    Uzer Kucuktulu
    Abstract Aim: To determine the effects of pentoxifylline, a methyl xanthine derivative on hepatic cell production of uninterferred lobe after portal vein branch ligation. Methods: Sixty-six rats were randomly allocated into 9 groups with 8 rats in PVL groups and 6 rats in sham operation groups. The portal branches of the median and the lateral liver lobes, corresponding to approximately 70% of the liver voluma were ligated in the PVL groups. The control group received 0.9% NaCl solution. The rats in the treatment groups received pentoxypilline at the dose of 50 mg/kg/dy. After 1,2,4 days of portal vein ligation in both PVL and PVNL lobes the levels of adenine nucleotides were determined and flowcytometric analysis of cell cycles were performed. Results: On the first day of portal branch ligation energy charge was significantly lower, in pentoxifylline treated group comparing to pentoxfylline untreated group, both in PVL and PVNL lobes (P<0.05). Proliferative indexes were 0.38 and 0.29 in pentoxifylline treated and pentoxifylline untreated PVNL lobes respectively (P<0.05). Conclusion: Pentoxifylline treatment resulted in an increase of percentage of calls entering mitosis phase on the first day after PVL, somehow accelerating the regenaration process. [source]

    Endothelial nitric oxide synthase is not essential for the development of fibrosis and portal hypertension in bile duct ligated mice

    LIVER INTERNATIONAL, Issue 5 2005
    Abraham Koshy
    Abstract: Background/Aims: It is postulated that nitric oxide (NO) is responsible for the hyperdynamic circulation of portal hypertension. Therefore, we investigated induction of fibrosis and hyperdynamic circulation in endothelial NO synthase knock-out (KO) mice. Methods: Fibrosis was induced by bile duct ligation. Hemodynamic studies were performed after portal vein ligation. All studies were performed in wild-type (WT) and KO mice. Results: Three to 4 weeks after bile duct ligation (BDL), both WT and KO groups had similar degrees of portal hypertension, 12 (9,14) and 11(8,15) mmHg, median (range), and liver function. Fibrosis increased from 0.0% in sham operated to 1.0 and 1.1% in WT and KO mice, respectively. Cardiac output was similar after portal vein ligation (20 and 17 ml/min in WT and KO mice, respectively). There was no difference in liver of mRNA for endothelin 1, inducible NO synthase (iNOS) and hem-oxygenase 1 (HO1); proteins of iNOS, HO1 and HO2; nor in endothelin A and B (EtA and EtB) receptor density between WT and KO mice after BDL. Conclusions: These results suggest that endothelial NO synthase is neither essential for the development of fibrosis and portal hypertension in bile duct ligated mice, nor for the hyperdynamic circulation associated with portal hypertension in the portal vein ligated mice. [source]

    Gene expression profile analysis of regenerating liver after portal vein ligation in rats by a cDNA microarray system

    LIVER INTERNATIONAL, Issue 3 2004
    Y Nagano
    Abstract: Aims: We assessed changes in gene expression of hypertrophied liver after portal vein ligation (PL) in a test group of rats compared to a control group, which had the same size liver but no PL. Methods: The portal veins of the left and median lobes in the test group were ligated in an initial operation. Four days after the PL, the liver volume of the posterior caudate lobe (5%) increased two-fold and comprised 10% of the liver. A 90% hepatectomy was then performed, leaving only the hypertrophied posterior caudate lobe, and leaving the normal anterior and posterior caudate lobes (10%) in the control (sham) group. A comparison of the expression profiles between two groups was performed using cDNA microarrays and the hepatic ATP level was measured. Results: The survival rate for the PL group was significantly higher than for the sham group at 4 days after the hepatectomy (56.3% and 26.7%, P<0.05). Gene expression of cyclin D1, proliferating cell nuclear antigen, cyclin A and B was upregulated, and the cyclin-dependent kinase inhibitor was downregulated. Increases were observed in: (i) pyruvate dehydrogenase, the tricarboxylic acid cycle cycle regulator, (ii) acyl-CoA dehydrogenase, the oxidation regulator, and (iii) cytochrome oxidases, the oxidative phosphorylation regulator. Hepatic ATP concentration after hepatectomy was better maintained in the PL group than in the sham group (0.48±0.01 ,mol/ml vs. 0.33±0.01 ,mol/ml, P<0.05). Conclusion: The regenerating liver increased tolerance for extended hepatectomy compared to normal liver. It is believed that this is because the induced rapid regeneration of the remaining liver after hepatectomy increases ATP metabolism. [source]

    Gastric mucosal resistance to acute injury in experimental portal hypertension

    BRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2001
    Sara Calatayud
    The gastric mucosa of portal hypertensive rats exhibits important microvascular changes and a nitric oxide (NO)-dependent hyperemia. This study analyses whether portal hypertensive mucosa exhibits changes in its ability to withstand aggression. Portal hypertension was induced by partial portal vein ligation (PPVL) or common bile duct ligation (CBDL) and gastric damage was induced by oral administration of ethanol or aspirin. Experiments were performed in conscious or anaesthetized rats and some animals were pre-treated with the NO-synthesis inhibitor L -NAME. Conscious PPVL or CBDL rats showed an increased resistance to the damaging effects of ethanol. Oral administration of aspirin produced less gastric damage in PPVL conscious rats than in the control group. The protective effects of portal hypertension were maintained in animals anaesthetized with ketamine and absent when pentobarbital was employed. Pre-treatment with L -NAME restored the damaging effects of ethanol and aspirin in PPVL rats without modifying the level of damage in control animals. Gastric bleeding induced by oral aspirin, as measured by the luminal release of 51Cr-labelled erythrocytes, was significantly greater in PPVL rats than in control animals. Semi-quantitiative analysis by RT , PCR of the mRNA for endothelial NO-synthase (eNOS), neuronal NOS (nNOS) and inducible NOS (iNOS) levels showed that the expression of iNOS was slightly increased in both the gastric mucosa and smooth muscle of PPVL rats. No changes were observed in eNOS and nNOS expression. Conscious portal hypertensive rats exhibit an enhanced resistance to acute gastric damage which is absent under the influence of some types of anaesthesia and seems related to an increased synthesis of nitric oxide. However, mucosal lesions in these animals show an augmented bleeding per area of injury. British Journal of Pharmacology (2001) 132, 309,317; doi:10.1038/sj.bjp.0703785 [source]

    Combined first-stage hepatectomy and colorectal resection in a two-stage hepatectomy strategy for bilobar synchronous liver metastases,

    BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2010
    M. Karoui
    Background: This study assessed the feasibility and outcomes of combined colorectal and hepatic resection as the first step of two-stage hepatectomy in patients with bilobar synchronous colorectal liver metastases. Methods: All patients with bilobar synchronous colorectal liver metastases who were considered for two-stage hepatectomy, combining resection of the primary tumour with the first stage of hepatectomy, between 2000 and 2008 were selected from a prospectively collected database at two institutions. Data were analysed retrospectively on an intention-to-treat basis. Results: Thirty-three patients were studied. Twenty patients received neoadjuvant chemotherapy. Combined colorectal resection and clearance of left-sided liver metastases was the first-stage procedure in all but one patient, in whom right clearance was performed. In 17 patients right portal vein ligation was undertaken at the same time. No patient died. Two patients had anastomotic leakage. Interval chemotherapy was given to 25 patients, five of whom also had percutaneous portal vein embolization. Twenty-five patients had the second-stage hepatectomy, but not eight patients with disease progression. There was one postoperative death after the second stage, and eight patients experienced morbidity. Median follow-up from the first stage was 28·7 months. Overall and disease-free survival rates for patients who completed the procedure were 80 and 44 per cent respectively at 3 years, and 48 and 22 per cent at 5 years. Conclusion: In patients with bilobar synchronous colorectal liver metastases who are candidates for two-stage hepatectomy, combined resection of the primary tumour and first-stage hepatectomy reduces the number of procedures, optimizes chemotherapy administration and may improve outcome. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

    Preventive effect of preoperative portal vein ligation on endotoxin-induced hepatic failure in hepatectomized rats is associated with reduced tumour necrosis factor , production

    BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 10 2000
    Dr S. Yachida
    Background Preoperative portal vein embolization successfully reduces the incidence of postoperative hepatic failure in which endotoxin is postulated to be involved. To identify the mechanism of this preventive effect, the relationship of endotoxin-induced liver injury with tumour necrosis factor (TNF) , and nitric oxide production in the peripheral blood, liver and spleen of rats subjected to preoperative portal vein branch ligation (PVL) was compared with that in rats undergoing sham operation. Methods Rats with PVL and those that underwent sham operation were subjected to resection of ligated liver lobes (PVL-Hx rats) and two-thirds hepatectomy (noPVL-Hx rats) respectively at day 5, followed by intravenous administration of endotoxin 200 ,g/kg body-weight at day 7. At various time intervals after endotoxin injection, the peripheral blood, liver and spleen tissues were harvested and analysed for TNF-, and nitric oxide production. Results The survival rates of noPVL-Hx and PVL-Hx rats at 48 h after endotoxin administration were 40 and 100 per cent respectively. The former rats showed more extensive liver injury as represented by higher serum aminotransferase and hyaluronate levels than the latter. Plasma concentrations of TNF-, at 1·5 h after endotoxin treatment were significantly higher in noPVL-Hx rats (mean(s.e.m.) 22 125(2175) pg/ml; n = 6) than PVL-Hx rats (8344(4076) pg/ml; n = 6) (P < 0·01). Consistent with this, expression of TNF-, messenger RNA in the liver and spleen was suppressed in PVL-Hx rats. In two-thirds hepatectomized rats, plasma TNF-, concentrations after endotoxin administration at 1, 2 and 3 days (14 350(2186), 26 375(2478) and 23 000(3745) pg/ml respectively; n = 6 each) were significantly higher than that before operation (9067(1559) pg/ml; n = 6) (P < 0·05), whereas those at 5 and 7 days (10 102(3616) and 8580(1427) pg/ml respectively; n = 6 each) showed no significant increase. Furthermore, nitric oxide production in peripheral blood and liver was suppressed by preoperative PVL. Conclusion Prevention of endotoxin-induced liver failure by preoperative PVL is associated with reduced production of TNF-, in the later phase of liver regeneration. © 2000 British Journal of Surgery Society Ltd [source]