Background/Aims Rapamycin, which is employed in the management of patients undergoing liver surgery, induces the synthesis of heme oxygenase-1 (HO-1) in some non-liver cell types. The aim was to ...investigate whether rapamycin can induce HO-1 expression in the liver, and to test the effects of rapamycin on liver function in the early phase of ischemia reperfusion (IR) injury. Methods Isolated rat hepatocytes and a rat model of segmental hepatic ischemia and reperfusion were employed. Bile flow was measured gravimetrically or by using indocyanine green. mRNA and protein (by quantitative PCR and Western blot, respectively) and blood concentrations of rapamycin, bilirubin, and liver marker enzymes were measured. Results In isolated hepatocytes, rapamycin induced a 6-fold increase in HO-1, comparable to that induced by cobalt proporphyrin (CoPP), and a 2-fold increase in peroxiredoxin-1. Pretreatment of rats with rapamycin resulted in a small increase in liver HO-1 expression, a 20% inhibition of the basal rate of bile flow, and a 50% inhibition in the rate of bile flow recovery after ischemia. CoPP increased basal bile flow by 20% and inhibited bile flow recovery by 50%. These effects were associated with small increases in the blood concentrations of bilirubin and liver marker enzymes. Conclusions Rapamycin, through HO-1 induction, has the potential to protect the liver against damage in the late phase of IR. The inhibition by rapamycin of bile flow indicates that its actions on liver function in the acute phase of IR injury are complex.
The aim of this article is to propose new criteria for the diagnosis and severity assessment of acute cholecystitis, based on a systematic review of the literature and a consensus of experts. A ...working group reviewed articles with regard to the diagnosis and treatment of acute cholecystitis and extracted the best current available evidence. In addition to the evidence and face‐to‐face discussions, domestic consensus meetings were held by the experts in order to assess the results. A provisional outcome statement regarding the diagnostic criteria and criteria for severity assessment was discussed and finalized during an International Consensus Meeting held in Tokyo 2006. Patients exhibiting one of the local signs of inflammation, such as Murphy's sign, or a mass, pain or tenderness in the right upper quadrant, as well as one of the systemic signs of inflammation, such as fever, elevated white blood cell count, and elevated C‐reactive protein level, are diagnosed as having acute cholecystitis. Patients in whom suspected clinical findings are confirmed by diagnostic imaging are also diagnosed with acute cholecystitis. The severity of acute cholecystitis is classified into three grades, mild (grade I), moderate (grade II), and severe (grade III). Grade I (mild acute cholecystitis) is defined as acute cholecystitis in a patient with no organ dysfunction and limited disease in the gallbladder, making cholecystectomy a low‐risk procedure. Grade II (moderate acute cholecystitis) is associated with no organ dysfunction but there is extensive disease in the gallbladder, resulting in difficulty in safely performing a cholecystectomy. Grade II disease is usually characterized by an elevated white blood cell count; a palpable, tender mass in the right upper abdominal quadrant; disease duration of more than 72 h; and imaging studies indicating significant inflammatory changes in the gallbladder. Grade III (severe acute cholecystitis) is defined as acute cholecystitis with organ dysfunction.
Background/Aims Ischemic preconditioning (IPC) and intermittent ischemia (INT) reduce liver injury following ischemia reperfusion in liver resections. Aged livers are at higher risk for ischemia ...reperfusion injury, but little is known of the effectiveness of IPC and INT in aged livers. The aim of this study was to investigate the effects of IPC and INT on ischemia reperfusion injury in aged livers. Methods A rat model of segmental hepatic ischemia (45 min) and reperfusion (60 min) was used. Bile flow, as an indicator of early hepatocyte damage and dynamic liver function, plasma concentrations of bilirubin, liver marker enzymes, and liver histology were assessed. Results In young rats (8–13 weeks), IPC regimes of 10 min clamping and 10 min reperfusion, and 5 min clamping and 30 min reperfusion, restored bile flow to 23 and 42%, respectively, of the initial value, compared to 14 and 88% for continuous clamping and controls, respectively. An INT regime of three cycles of alternating 15 min perfusion and 15 min clamping gave a substantially greater (70%) restoration of bile flow. In aged rats (20–24 months), the IPC regimes did not give any restoration of bile flow. By contrast, the INT regime restored bile flow to 68%. Plasma bilirubin concentrations were lowest in the INT groups, whereas alanine transaminase concentrations for the IPC and INT groups compared with the continuous clamping groups showed no significant differences. Conclusions In young rats, INT is more effective than IPC in restoring the immediate consequences of IP-induced damage to hepatocytes and liver function after ischemia-reperfusion. In aged rats INT, but not IPC, reverses hepatocyte damage and restores liver function. INT may promote better hepatocyte and liver function than IPC following the surgical resection of aged livers.
Traditionally a 1-cm margin has been accepted as the gold standard for resection of colorectal liver metastases. Evidence is emerging that a lesser margin may provide equally acceptable outcomes, but ...a critical margin, below which recurrence is higher and survival poorer, has not been universally agreed. In a recent publication, we reported peri-operative morbidity and clear margin as the two independent prognostic factors. The aim of the current study was to further analyse the effect of the width of the surgical margin on patient survival to determine whether a margin of 1mm is adequate.
Two hundred and sixty-one consecutive primary liver resections for colorectal metastases were analysed from 1992 to 2007. The resection margins were assessed by microscopic examination of paraffin sections. The initial analysis was performed on five groups according to the resection margins: involved margin, 0–1mm, >1–<4mm, 4–<10mm and ≥ 10mm. Subsequent analysis was based on two groups: margin <1mm and >1mm.
With a median follow-up of 4.7 years, the overall 5-year patient and disease-free survival were 38% and 22%, respectively. There was no significant difference in patient- or disease-free survival between the three groups with resection margins >1mm. When a comparison was made between patients with resection margins ≤1mm and patients with resection margins >1mm, there was a significant 5-year patient survival difference of 25% versus 43% (P < 0.04). However, the disease-free survival difference did not reach statistical significance (P= 0.14).
In this cohort of patients, we have demonstrated that a resection margin of greater than 1mm is associated with significantly improved 5-year overall survival, compared with involved margins or margins less than or equal to 1mm. The possible beneficial effect of greater margins beyond 1mm could not be demonstrated.
Liver resection and liver transplantation have been successful in the treatment of liver tumors and end-stage liver disease. This success has led to an expansion in the pool of patients potentially ...treatable by liver surgery and, in the case of transplantation, to a shortage of liver donors. At present, there are significant numbers of potential candidates for liver resection and liver donation who have fatty livers, are aged, or have livers damaged by chemotherapy. All of these are at high risk for ischemic reperfusion (IR) injury. The aims of this review are to assess current knowledge of the clinical effectiveness of ischemic preconditioning and intermittent ischemia in reducing IR damage in liver surgery; to evaluate the use of bile flow as a sensitive indicator of IR liver damage; and to analyze the molecular mechanisms, especially intracellular Ca2+, involved in IR injury and ischemic preconditioning. It is concluded that bile flow is a sensitive indicator of IR injury. Together with reactive oxygen species (ROS) and other extracellular and intracellular signaling molecules, intracellular Ca2+ in hepatocytes plays a key role in the normal regulation of bile flow and in IR-induced injury and cell death. Ischemic preconditioning is an effective strategy to reduce IR injury but there is considerable scope for improvement, especially in patients with fatty and aged livers. The development of effective new strategies to reduce IR injury will depend on improved understanding of the molecular mechanisms involved, especially by gaining a better perspective of the relative importance of the various intrahepatocyte signaling pathways involved.
Ischemia and reperfusion (IR) injury of the liver is associated with impaired bile secretion, but the effects of ischemic preconditioning (IPC) and intermittent ischemia (INT) on bile flow are ...unknown. A rat model of segmental (60%-70%) hepatic ischemia and reperfusion was employed to test the effects of IPC and INT on bile flow. Continuous clamping for 45 min (CC) substantially reduced bile flow, and this did not recover after 60 min of reperfusion. IPC and INT caused a significant recovery of bile flow. The elevation in plasma liver marker enzymes induced by CC was not reduced by IPC and INT. Light microscopy showed mild hepatocyte damage in all groups. In the CC group, the amount of F-actin localized around the bile canaliculi in the ischemic lobes was less than that in the nonischemic lobes, but this difference was not observed in the IPC and INT groups. It is concluded that IPC and INT substantially alleviate the decrease in bile flow induced by ischemia. Bile flow may be useful in the assessment of IR injury.
Ischemia and reperfusion (IR) injury of the liver is associated with impaired bile secretion, but the effects of ischemic preconditioning (IPC) and intermittent ischemia (INT) on bile flow are ...unknown. A rat model of segmental (60%-70%) hepatic ischemia and reperfusion was employed to test the effects of IPC and INT on bile flow. Continuous clamping for 45 min (CC) substantially reduced bile flow, and this did not recover after 60 min of reperfusion. IPC and INT caused a significant recovery of bile flow. The elevation in plasma liver marker enzymes induced by CC was not reduced by IPC and INT. Light microscopy showed mild hepatocyte damage in all groups. In the CC group, the amount of F-actin localized around the bile canaliculi in the ischemic lobes was less than that in the nonischemic lobes, but this difference was not observed in the IPC and INT groups. It is concluded that IPC and INT substantially alleviate the decrease in bile flow induced by ischemia. Bile flow may be useful in the assessment of IR injury.
Background To date, there is no uniform and standardized manner of defining pancreatic anastomoses after pancreatic resection. Methods A systematic search was performed to determine the various ...factors, either related to the pancreatic remnant after pancreatic resection or to types of pancreatoenteric anastomoses that have been shown to influence failure rates of pancreatic anastomoses. Results Based on the data obtained, we formulated a new classification that incorporates factors related to the pancreatic remnant, such as pancreatic duct size, length of mobilization, and gland texture, as well as factors related to the pancreatoenteric anastomosis, such as the use of pancreatojejunostomy/pancreatogastrostomy; duct-to-mucosa anastomosis; invagination (dunking) of the remnant into the jejunum or stomach; and the use of a stent (internal or external) across the anastomosis. Conclusion By creating a standardized classification for recording and reporting of the pancreatoenterostomy, future publications would allow a more objective comparison of outcomes after pancreatic surgery. In addition, use of such a classification might encourage studies evaluating outcomes after specific types of anastomoses in certain clinical situations that could lead to the formulation of best practice guidelines of anastomotic techniques for a particular combination of findings in the pancreatic remnant.
Female patients exhibit better survival and less hepatic damage from ischemia reperfusion (IR) injury following surgery. However, the effects of sex and estrogens on liver function in the acute phase ...of IR are not well understood. Objective. The aim was to investigate this question.
A rat model of segmental hepatic ischemia was employed. Rats were pre-treated with the estrogen receptor antagonist ICI182,780 and/or the estrogen receptor agonist 17β-estradiol. Bile flow, blood concentrations of bilirubin and liver enzymes were measured, and liver histology was assessed.
Bile flow recovery immediately after the initiation of reperfusion was faster in females than in males. ICI182,780 reduced the rate of bile flow recovery in females but this reduction was not reversed by co-administration of 17 β-estradiol. In males, 17 β-estradiol alone did not enhance bile flow recovery. The changes in bile flow recovery observed under a given condition were correlated with small changes in blood liver enzymes and liver histology.
Sex has a significant influence on the early recovery of liver function in the acute phase of IR injury. However, in female rats estrogen receptors play only a limited role in mediating enhanced recovery of liver function.
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