Application of hepatic tolerance tests to the functional reserve assessment in rat models of fatty liver

Can preoperative diffusion-weighted MRI predict postoperative hepatic insufficiency after curative resection of HBV-related hepatocellular carcinoma? A pilot study

Liver fibrosis determines the functional liver reserve. Several studies have reported that the apparent diffusion coefficient (ADC) values of diffusion-weighted magnetic resonance imaging (DW-MRI) can assess liver fibrosis. We investigated whether DW-MRI predicts postoperative hepatic insufficiency and liver fibrosis in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Twenty-six patients with HBV-related HCC who received preoperative DW-MRI on a 3-T MRI system were enrolled between July and December 2008. ADC values were measured twice by two observers. Three "b values" were used: 50, 400 and 800 s/mm(2). Postoperative hepatic insufficiency was defined as persistent hyperbilirubinemia (total bilirubin level >5 mg/dl for more than 5 days after surgery) or postoperative death without other causes. The mean age (21 men and 5 women) was 51.4 years. Three patients experienced postoperative hepatic insufficiency. liver stiffness measurement predicted postoperative hepatic insufficiency, advanced fibrosis (F3-4), and cirrhosis significantly [area under the receiving operator characteristic curve (AUROC)=0.942, 0.771 and 0.818, respectively, with P=.047, 0.048 and 0.006, respectively]; ADC values of DW-MRI, however, did not (AUROC=0.797, 0.648 and 0.491, respectively, with P=.100, 0.313 and 0.938, respectively). Reliability of ADC values between right and left hepatic lobes (rho=0.868 and rho=0.910 in the first and second measures of Observer A; rho=0.865 and rho=0.831 in the first and second measures of Observer B) was high and the intra- and interobserver reliability (rho=0.958 in observer A and rho=0.977 in observer B; rho=0.929 in the first measure and rho=0.978 in the second measure between the two observers) were high. All reliability was significant (P<.001). Our results suggest that DW-MRI on a 3-T MRI system is not suitable for predicting postoperative hepatic insufficiency, advanced liver fibrosis, and cirrhosis in patients with HBV-related HCC, despite significantly high reliability.

Prediction of postoperative hepatic insufficiency by liver stiffness measurement (FibroScan((R))) before curative resection of hepatocellular carcinoma: a pilot study

Background

Liver stiffness measurement (LSM) using transient elastography (FibroScan^®) reflects the degree of hepatic fibrosis. This prospective study investigated how well LSM predicts the development of hepatic insufficiency after curative liver resection surgery for hepatocellular carcinoma.

Methods

The study enrolled 72 consecutive patients who underwent a preoperative LSM to assess the degree of liver fibrosis followed by curative liver resection surgery for hepatocellular carcinoma between July 2006 and December 2007. The primary end point was the development of hepatic insufficiency.

Results

The mean age of the patients was 54.9 years. Twenty patients (27.7%) had chronic hepatitis and 52 (72.3%) had cirrhosis (44 and 8 patients showed Child-Pugh class A and B, respectively). The mean LSM was 17.1 kPa. Twelve patients (16.6%) had segmentectomy only, 16 patients (22.2%) had bisegmentectomy, and 44 patients (61.2%) had lobectomy. Nine patients (12.5%) had stage I tumor, 56 (77.7%) had stage II, and 7 (9.8%) had stage III. Univariate and subsequent multivariate analyses revealed that preoperative LSM was the only independent risk factor for predicting the development of postoperative hepatic insufficiency (cutoff, 25.6 kPa; P = 0.001; relative risk, 19.14; 95% confidence interval, 2.71–135.36).

Conclusions

LSM is potentially useful to predict the development of postoperative hepatic insufficiency in patients with hepatocellular carcinoma undergoing curative liver resection surgery.

Prediction of postoperative hepatic insufficiency by liver stiffness measurement (FibroScan((R))) before curative resection of hepatocellular carcinoma: a pilot study

BACKGROUND

Liver stiffness measurement (LSM) using transient elastography (FibroScan((R))) reflects the degree of hepatic fibrosis. This prospective study investigated how well LSM predicts the development of hepatic insufficiency after curative liver resection surgery for hepatocellular carcinoma.

METHODS

The study enrolled 72 consecutive patients who underwent a preoperative LSM to assess the degree of liver fibrosis followed by curative liver resection surgery for hepatocellular carcinoma between July 2006 and December 2007. The primary end point was the development of hepatic insufficiency.

RESULTS

The mean age of the patients was 54.9 years. Twenty patients (27.7%) had chronic hepatitis and 52 (72.3%) had cirrhosis (44 and 8 patients showed Child-Pugh class A and B, respectively). The mean LSM was 17.1 kPa. Twelve patients (16.6%) had segmentectomy only, 16 patients (22.2%) had bisegmentectomy, and 44 patients (61.2%) had lobectomy. Nine patients (12.5%) had stage I tumor, 56 (77.7%) had stage II, and 7 (9.8%) had stage III. Univariate and subsequent multivariate analyses revealed that preoperative LSM was the only independent risk factor for predicting the development of postoperative hepatic insufficiency (cutoff, 25.6 kPa; P = 0.001; relative risk, 19.14; 95% confidence interval, 2.71-135.36).

CONCLUSIONS

LSM is potentially useful to predict the development of postoperative hepatic insufficiency in patients with hepatocellular carcinoma undergoing curative liver resection surgery.

Acute pancreatitis: animal models and recent advances in basic research

Acute pancreatitis (AP) is characterized by edema, acinar cell necrosis, hemorrhage, and severe inflammation of the pancreas. Patients with AP present with elevated blood and urine levels of pancreatic digestive enzymes, such as amylase and lipase. Severe AP may lead to systemic inflammatory response syndrome and multiorgan dysfunction syndrome, which account for the high mortality rate of AP. Although most (>80%) cases of AP are associated with gallstones and alcoholism, some are idiopathic. Although the pathogenesis of AP has not yet been elucidated, a common feature is the premature activation of trypsinogen within pancreatic tissues, which triggers autodigestion of the gland. Recent advances in basic research suggest that etiologic factors including cyclooxygenase-2, substance P, and angiotensin II may have novel roles in this disease. Basic research data obtained thus far have been based on animal models of AP ranging from mild edematous pancreatitis to severe necrotizing pancreatitis. In view of this, an adequate selection of experimental animal models is of paramount importance. Notwithstanding these animal models, it should be emphasized that none of these models mimic the clinical situation where varying degrees of severity usually occur. In this review, commonly used animal models of AP will be critically evaluated. A discussion of recent advances in our knowledge about AP risk factors is also included.

Measurement of serum hyaluronic acid level during the perioperative period of liver resection for evaluation of functional liver reserve

BACKGROUND AND AIM

The serum hyaluronic acid (HA) concentrations reflect the degree of hepatic fibrosis and sinusoidal endothelial cell damage. The HA concentrations were examined to evaluate liver damage during the perioperative period of hepatectomy.

METHODS

The HA level of serum samples from 79 patients who underwent a hepatectomy was measured, and the results were compared to conventional liver function tests, the degree of fibrosis, liver regeneration and complications.

RESULTS

Hyaluronic acid concentrations correlated with the severe fibrosis or histological activity index, and also correlated with liver function tests including transaminase level, platelet counts, prothrombin time activity, indocyanine green retention rate at 15 min (ICG R15), liver activity at 15 min by technetium-99m galactosyl human serum albumin scintigraphy (LHL 15), and portal pressure. The HA level postoperatively correlated with liver function, especially with total bilirubin. Hyaluronic acid levels at day 28 postoperatively correlated with ICG R15 and LHL 15. The hyaluronic acid level before surgery and at day 28 postoperatively correlated with the regeneration of remnant liver in major hepatectomy. The HA levels were significantly higher in patients with hepatic failure or prolonged ascites.

CONCLUSION

Our results indicate that the measurement of the HA level is useful for monitoring liver damage or predicting complications associated with liver surgery.

Hepatic indocyanine green uptake and excretion in a rabbit model of steatosis

Transplantation of a fatty liver is associated with a higher incidence of primary non-function of the graft. Indocyanine green (ICG) has been used for assessing hepatic dysfunction but not for quantifying liver steatosis. New Zealand white rabbits were fed a normal diet (group A) or a high-cholesterol (2%) diet for 4, 8, and 12 weeks in groups B, C, and D, respectively. Laparotomy was performed for liver exposure. Hepatic artery, portal vein, and total blood flow, hepatic microcirculation, portal pressure, liver function parameters, and blood cholesterol levels were measured. The hepatic ICG concentration was measured using near-infrared spectroscopy, and its uptake and excretion rates were calculated. The severity of steatosis was assessed from liver biopsy specimens by a semiquantitative grading system. Cholesterol feeding resulted in mild steatosis after 4 weeks and in moderate steatosis after 8 and 12 weeks. Mild steatosis was associated with insignificant changes in haemodynamic parameters, liver function, and ICG handling as compared with controls. Moderate steatosis caused a significant reduction in portal and total hepatic blood flow and microcirculation with a significant increase in hepatic artery flow and portal pressure. These haemodynamic changes were associated with a significant alteration in liver function tests. With moderate steatosis, ICG uptake and excretion were significantly reduced. The ICG uptake rate significantly correlated with total blood flow and microcirculation. The ICG excretion rate significantly correlated with the changes in bilirubin, liver enzymes, and albumin. Direct ICG quantification by near-infrared spectroscopy could be used to assess the severity of hepatic steatosis by reflecting impaired parenchymal perfusion and liver dysfunction.