Safe upper limit of intermittent hepatic inflow occlusion for liver resection in cirrhotic rats

The effect of the number of hepatic inflow occlusion times on the prognosis of ruptured hepatocellular carcinoma patients after hepatectomy

Background and aim

It has been previously reported that inflow occlusion does not affect postoperative outcomes in hepatocellular carcinoma patients. However, for patients with ruptured hepatocellular carcinoma(rHCC), the effect of hepatic inflow occlusion and the number of occlusion times on the prognosis is unknown.

Methods

203 patients with ruptured hepatocellular carcinoma were enrolled in this study. They were first divided into the non-hepatic inflow occlusion (non-HIO) group and the hepatic inflow occlusion (HIO) group. The Kaplan–Meier method was used to compare the recurrence-free survival and overall survival between the two groups. Patients in the HIO group were further divided into one-time HIO and two times HIO groups. KM method was also used to compare the two groups. Finally, independent risk factors affecting RFS and OS were determined by multivariate Cox regression analysis.

Result

In the non-HIO group, 1-,3- and 5-year OS rates were 67.0%, 41.0%, and 22.0%respectively, and RFS rates were 45.0%, 31.0%, and 20.0% respectively; In the one-HIO group, the 1-,3-, and 5-year OS rates were 55.1%, 32.1%, and 19.2% respectively, and RFS rates were 33.3%, 16.7%, and 7.7% respectively; In the two-HIO group, 1-,3-, and 5-year OS rates were 24.0%, 0.0%, and 0.0% respectively, and RFS rates were 8.0%, 0.0%, and 0.0% respectively. By Cox regression analysis, HIO was an independent risk factor for a poor prognosis in rHCC patients.

Conclusion

One time hepatic inflow occlusion did not affect postoperative OS, but negatively affected the RFS of rHCC patients; two times hepatic inflow occlusion negatively affected the postoperative OS and RFS in patients with rHCC.

The Protective Effect of Traditional Chinese Medicine on Liver Ischemia-Reperfusion Injury

Liver ischemia-reperfusion (I/R) injury occurs during transplantation and major hepatic surgery, which may lead to postoperative liver dysfunction. More and more traditional Chinese medicines (TCMs) have been used to treat liver ischemia-reperfusion injury. The purpose of this review is to evaluate the different protective effects of TCMs in the treatment of liver ischemia-reperfusion injury and to summarize its possible mechanisms. The results indicate that TCMs attenuate liver I/R injury via multiple mechanisms, including antioxidation stress, anti-inflammatory response, antiapoptosis, and inhibiting endoplasmic reticulum stress. However, the in-depth mechanism of the protective effects of these traditional Chinese medicines still remains unknown.

Hepatoprotective effects of limb ischemic post-conditioning in hepatic ischemic rat model and liver cancer patients via PI3K/ERK pathways

The most effective way of treating liver cancer is surgical resection, which usually requires blocking the hepatic portal circulation, and may result in hepatic ischemia-reperfusion injury (HIRI). It is of paramount importance to control HIRI for liver cancer surgical resection. In this study, a 70% ischemia-reperfusion (I/R) model of rat liver was established, and the protective effect and mechanism of limb ischemic post-conditioning (LIPOC) on HIRI was investigated. We show that LIPOC has a protective effect on hepatic ischemia-reperfusion injury in rats, which reduces the elimination of superoxide dismutase, thereby increasing oxygen free radical scavenging, decreasing lipid peroxidation, inhibiting neutrophil aggregation, as well as reducing TNFα, IL1β, and other inflammatory cytokines. In addition, LIPOC inhibited the apoptosis of hepatocytes induced by I/R injury, and decreased the Bax/Bcl-2 ratio. Furthermore, LIPOC promoted the phosphorylation of Akt and ERK1/2. The use of PI3K inhibitor LY294002 and ERK1/2 blocker PD98059 inhibited the phosphorylation of Akt and ERK1/2 caused by LIPOC and abolished the injury protection of liver I/R. Moreover, through 16 cases of hepatocellular carcinoma resections, we found that short-term LIPOC treatment significantly suppressed the elevated alanine aminotransferase, aspartic transaminase, and total bilirubin in the early post-operation of liver resection, and reduced reperfusion injury to the ischemic liver. In summary, our study demonstrates that LIPOC could be an effective method for HIRI in the clinical implementation of liver resection and uncovers the potential mechanism of LIPOC in the protective effects of HIRI.

How much ischemia can the liver tolerate during resection?

The use of vascular inflow occlusion (VIO, also known as the Pringle maneuver) during liver surgery prevents severe blood loss and the need for blood transfusion. The most commonly used technique for VIO entails clamping of the portal triad, which simultaneously occludes the proper hepatic artery and portal vein. Although VIO is an effective technique to reduce intraoperative blood loss, it also inevitably inflicts hepatic ischemia/reperfusion (I/R) injury as a side effect. I/R injury induces formation of reactive oxygen species that cause oxidative stress and cell death, ultimately leading to a sterile inflammatory response that causes hepatocellular damage and liver dysfunction that can result in acute liver failure in most severe cases. Since the duration of ischemia correlates positively with the severity of liver injury, there is a need to find the balance between preventing severe blood loss and inducing liver damage through the use of VIO. Although research on the maximum duration of hepatic ischemia has intensified since the beginning of the 1980s, there still is no consensus on the tolerable upper limit. Based on the available literature, it is concluded that intermittent and continuous VIO can both be used safely when ischemia times do not exceed 120 min. However, intermittent VIO should be the preferred technique in cases that require >120 min duration of ischemia.

Evaluation of the Safe Ischemic Time of Clamping During Intermittent Pringles Maneuver in Rabbits

BACKGROUND

The liver is the most commonly injured organ in blunt abdominal trauma. Although major hepatic bleeding may be partially controlled with portal triade clamping (the Pringle's maneuver), continuous prolonged clamping results in liver ischemia.

OBJECTIVES

The purpose of this study was to determine the safe time of Pringle maneuver based on pathologic changes of liver in rabbit models.

MATERIALS AND METHODS

In an experimental study, 20 New-Zealand white rabbits were selected. In laparotomy, a blunt dissector was passed through the foramen of Winslow and the hepato-duodenal ligament encircled with an umbilical tape. En masse Pringle maneuver was performed using atraumatic flexible clamps. Rabbits were divided into four groups based on Pringle maneuver time (30 minutes, 45 minutes, 60 minutes, and 75 minutes). A hepatic biopsy was performed at the beginning of operation. The degree of tissue injury was evaluated using blood markers.

RESULTS

There were five rabbits in each group. At the end of 60 minutes ischemia, only minor alterations were observed in pathological specimens. At the end of 75 minutes, hepatocyte damage and necrosis were observed. The serum levels of alanine aminotransferase (Group A: P = 0.02; Group B: P = 0.01; Group C: P = 0.0002; Group D: P = 0.01) and Aspartate aminotransferase (Group A: P = 0.03; Group B: P = 0.002; Group C: P = 0.0004; Group D: P = 0.0003) were significantly increased post-operatively. The maximum level was in the first day after operation.

CONCLUSIONS

Continuous portal triade clamping (the Pringle maneuver) during liver ischemia (30 and 45 minutes) in rabbits resulted in no ischemic change. Increasing time of clamping to 30 minutes was safe in intermittent Pringle maneuver.

Protective effect of ischemic postconditioning against hepatic ischemic reperfusion injury in rat liver

Purpose

The efficiency of ischemic postconditioning (IPC) was evaluated in a rat model of ischemic liver. Concentration of survivin of liver tissue correlated with the degree of antiapoptosis, so survivin was estimated to evaluate the efficiency of IPC on ischemic reperfusion (IR) injury.

Methods

Twenty-four healthy rats were divided to three groups (SHAM, IR, and IPC). Rats in the SHAM group displayed no change during 3 hours. Rats in the IR group were ischemic within 1 hour of clamping the left hepatic artery and left portal vein. Reperfusion for 2 hours was then done. IPC group, intermittent 2, 3, 5, and 7 minutes of reperfusion followed by 1 hour of warm ischemia. Two-minute reocclusion was done after each reperfusion. Rat sera were analyzed for AST and ALT, and Western blot analysis of rat liver tissue of rats evaluated malondialdehyde (MDA) and survivin.

Results

MDA in the liver tissue of rats in the IR and IPC group were significantly high than in the liver tissue of the SHAM group (P = 0.003 and P = 0.008, respectively). Survivin was higher in the IPC group than in the SHAM and IR groups (P = 0.021 and P = 0.024, respectively).

Conclusion

IPC could not prevent lipid oxidation in liver cell mitochondria, but did aid in the regeneration of ischemic injured liver cells. The results indicate that IPC can suppress the apoptosis of liver cells and reduce reperfusion injury of liver tissue.

Protective effects of Atractylodes macrocephala polysaccharide on liver ischemia-reperfusion injury and its possible mechanism in rats

Atractylodes macrocephala polysaccharide (AMP), a traditional Chinese medicine, is thought to have protective effects against liver injury. Therefore, this study was designed to explore the effects of AMP on hepatic ischemia-reperfusion injury (IRI) and elucidate the possible mechanisms. Ninety-six Sprague-Dawley rats were randomly divided into four groups with 24 rats per group: a normal control group, an IRI group, an AMP-treated group (0.4 g/kg/d) and a bifendate-treated group (100 mg/kg). Rats were treated with AMP or bifendate once daily for seven days by gastric gavage. The normal control group and the IRI model group received an equivalent volume of physiological saline. At 1, 6 and 24 h after surgery, the rats were killed and liver tissue samples were obtained to determine interleukin-1 (IL-1) expression by Western blotting and nuclear factor-κB (NF-κB) expression by immunohistochemistry. Liver morphology was assessed by microscopy and transmission electron microscopy. Blood samples were obtained to measure liver function (alanine aminotransferase, aspartate aminotransferase, total bilirubin and direct bilirubin). AMP significantly reduced the elevated expression of markers of liver dysfunction and the hepatic morphologic changes induced by hepatic IRI in rats. AMP also markedly inhibited IRI-induced lipid peroxidation and altered the activities of the antioxidant enzyme superoxide dismutase and malondialdehyde levels. Moreover, pretreatment with AMP suppressed the expression of interleukin-1β and NF-kB in IRI-treated rats. These results suggest that AMP exerts protective and therapeutic effects against hepatic IRI in rats, which might be associated with its antioxidant properties and inhibition of NF-κB activation. More studies are needed to better understand the mechanisms underlying the protective effects of AMP on hepatic IRI.

Avaliação bioquímica dos efeitos do pré-condicionamento isquêmico após isquemia e reperfusão hepática em ratos

OBJETIVO: Comparar a lesão hepatocelular ocasionada pelo emprego do pré-condicionamento isquêmico e de duas outras modalidades de clampeamento tríade portal: clampeamento contínuo e intermitente. MÉTODO: Quarenta ratos Wistar foram divididos em quatro grupos de 10 animais cada. No Grupo Sham nenhuma espécie de clampeamento foi adotada. Nos outros três, provocamos isquemia de quarenta minutos por meio do clampeamento do pedículo hepático. No Grupo I esta isquemia foi contínua. No Grupo II, também contínua, mas precedida de cinco minutos de isquemia e 10 minutos de reperfusão (précondicionamento isquêmico). No Grupo III foi realizada isquemia intermitente em ciclos de 10 min de isquemia e cinco minutos de reperfusão. Para avaliar a lesão hepatocelular foi adotada a dosagem de transaminase glutâmico oxalacética (TGO), glutâmico pirúvica (TGP) e lactato desidrogenase (LDH), aferidas no início e no final dos procedimentos. RESULTADOS: Não houve diferença estatística nos valores basais das enzimas estudadas, demonstrando uniformidade nos grupos. Os quatro grupos apresentaram variação significativa de todas as enzimas entre os dois momentos de coleta, porém de forma diferenciada. A variação no Grupo Sham foi menor que a do grupo II. Este foi semelhante ao grupo III e em todos a elevação foi significativamente menor que no grupo I (D do Sham CONCLUSÕES: Em ratos Wistar o clampeamento contínuo do pedículo hepático, precedido de um ciclo de cinco minutos de isquemia e 10 minutos de reperfusão (pré-condicionamento isquêmico) provoca menor lesão hepática do que o clampeamento contínuo e apresenta resultados comparáveis aos obtidos através da utilização do clampeamento intermitente, em fígados normais submetidos a um período de isquemia hepática de 40 minutos e um tempo total de cirurgia de 60 minutos.

Liver resection for hepatocellular carcinoma on cirrhosis: analysis of mortality, morbidity and survival—a European single center experience

AIMS

To evaluate short- and long-term results of liver resections and prognostic factors in cirrhotic patients with hepatocellular carcinoma.

STUDY DESIGN

A single-unit, retrospective study analyzing 216 patients with histologically confirmed cirrhosis who underwent hepatic resection for hepatocellular carcinoma. All clinico-pathologic and follow-up data were collected prospectively.

RESULTS

Child A patients had a significantly lower in-hospital mortality rate compared to Child B-C: 4.7 vs 21.3% (p=0.0003). Overall morbidity rate was 38.4%; multiple logistic regression analysis identified liver function, hepatic pedicle clamping time, number of nodes and transfusion rate as independent predictors for post-operative complications. Overall and disease-free 5-year survival rates were 34.1 and 25.2%. Multivariate analysis showed that Child A, radical resection, tumour size < or =5 cm and, absence of vascular invasion were independent prognostic factors for long-term survival. No significant differences in overall and disease-free survival were found according to the type of resection (anatomic vs non-anatomic).

CONCLUSIONS

Patients with preserved liver function and small-size, single-node hepatocellular carcinomas are the best candidates for hepatic resection.

Effect of protein kinase C during hepatocyte hypoxic precondition

AIM

To investigate the effects of protein kinase C (PKC) on hypoxic preconditioning (HP) for hepatocyte.

METHODS

Through a normal liver cell HP model, PKC inhibitor and activator were utilized to analyze the phosphorylation of PKC. The cellular structure and viability were also observed. All the data were statistically analyzed.

RESULTS

Compared with the phosphorylation of PKC in the control without HP [(710.5±78.8) fkat/g], the phosphorylation of PKC was obviously increased in HP treated model [(1823.7±268.2) fkat/g] and PMA treated model [(2 541.2±326.5) fkat/g] (P<0.01). Cellular changes were less. In addition, opposite changes were found in PKC inhibited groups, and the phosphorylation of PKC was [(1 088.0±89.3) fkat/g] (P<0.01).

CONCLUSION

The activation of PKC is the important chain of HP in the preservation of liver cell, and its mechanism may be involved in protein phosphorylation.

Evaluation of a canine model of secondary hypersplenism induced by splenic vein ligation

AIM

To introduce and evaluate a canine model of secondary hypersplenism induced by splenic vein ligation.

METHODS

Eighteen healthy mongrel dogs were randomly divided into three groups. The first group (n = 4) underwent laparotomy, the second (n = 10) and third groups (n = 4) underwent laparotomy plus ligation of splenic vein and its collateral branches to induce congestive splenomegaly. At the end of the third week, splenectomy was performed in the third group. The blood cell counts for peripheral venous blood were determined weekly, and the radiographic and histopathological changes of spleen also obtained regularly.

RESULTS

The erythrocyte and platelet counts decreased in the first week, and were significantly lowered (erythrocyte count of (6.8 ± 1.2)×10¹²/L in control vs (5.1± 0.7)×10¹²/L in second group, P<0.01; and platelet counts of (398 ± 58)×10⁹/L vs (230 ± 86)109/L, P<0.05 respectively) at the end of 3rd week after splenic vein ligation thereafter sustained. The splenomegaly, erythrocytopenia and thrombocytopenia had remained over 9 weeks. No significant changes of the leukocyte counts were observed after splenic vein ligation throughout the experiment (P>0.05). The abnormal status of erythrocytopenia and thrombocytopenia was ameliolated by splenectomy, and the erythrocyte and platelet counts were similarly to the levels of the control group in the second week after splenectomy. After the end of 3rd week after splenic vein ligation, the splenic histopathological changes conformed to the changes of chronic congestive splenomagely.

CONCLUSION

The method of splenic vein ligation to induce experimental secondary hypersplenism is simple and effective. This is a relative ideal model for surgical or interventional therapy on hypersplenism.

Estrogen reduces CCL4- induced liver fibrosis in rats

AIM: Chronic liver diseases, such as fibrosis or cirrhosis, are more common in men than in women. This gender difference may be related to the effects of sex hormones on the liver. The aim of the present work was to investigate the effects of estrogen on CCL₄-induced fibrosis of the liver in rats.

METHODS: Liver fibrosis was induced in male, female and ovariectomized rats by CCL₄ administration. All the groups were treated with estradiol (1 mg/kg) twice weekly. And tamoxifen was given to male fibrosis model. At the end of 8 wk, all the rats were killed to study serum indicators and the livers.

RESULTS: Estradiol treatment reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), hyaluronic acid (HA) and type IV collagen (CIV) in sera, suppressed hepatic collagen content, decreased the areas of hepatic stellate cells (HSC) positive for α-smooth muscle actin (α-SMA), and lowered the synthesis of hepatic type I collagen significantly in both sexes and ovariectomy fibrotic rats induced by CCL₄ administration. Whereas, tamoxifen had the opposite effect. The fibrotic response of the female liver to CCL₄ treatment was significantly weaker than that of male liver.

CONCLUSION: Estradiol reduces CCL₄-induced hepatic fibrosis in rats. The antifibrogenic role of estrogen in the liver may be one reason for the sex associated differences in the progression from hepatic fibrosis to cirrhosis.