Haemodynamic alterations and their morphological basis in biliary obstruction

Non-invasive diagnosis of large oesophageal varices with FibroTest in patients with cirrhosis: a preliminary retrospective study

BACKGROUND AND AIMS

Primary prevention of variceal bleeding with beta-blockers improves survival in patients with large oesophageal varices (LOV). Therefore, cirrhotic patients frequently undergo screening endoscopy. As portal hypertension is related to liver fibrosis, this study aimed to assess the predictive value of FibroTest, a non-invasive marker of liver fibrosis, for the diagnosis of LOV in cirrhotic patients.

METHODS

Ninety-nine cirrhotic patients had clinical examination, blood sample (liver function tests, platelet count, FibroTest) and upper endoscopy. Measurements of endoscopic and biochemical parameters were made blindly. Sensitivity, specificity, predictive values and area under the receiver operating characteristic curves were assessed for FibroTest, platelet count and Child-Pugh score. The main endpoint was the presence of LOV.

RESULTS

Platelet count, prothrombin time, ascites, FibroTest and Child-Pugh class were significantly different among patients with or without LOV. FibroTest had the highest discriminative power with an area under receiver operating characteristics curves of 0.77 (SE=0.06), compared with 0.64 (0.08) and 0.68 (0.08) for platelet count and Child-Pugh score, respectively (P=0.08). A cut-off at 0.80 had a 86% negative predictive value for the diagnosis of LOV (Se=92%, Sp=21%).

CONCLUSION

FibroTest could aid in the diagnosis of LOV and may therefore reduce the indication of endoscopic screening in cirrhotic patients.

Gastropathy and defense mechanisms in common bile duct ligated portal hypertensive rats

Portal hypertensive gastropathy is associated with a broad spectrum of gastric mucosal damage inspite of decreased gastric acid secretion, suggestive of compromised endogenous protective mechanisms. To determine the mechanisms of damage in portal hypertensive gastropathy we measured lipid peroxidation, glutathione, antioxidant and lysosomal enzymes in gastric mucosal homogenates from male Wistar rats with elevated intrasplenic pulp pressure, eighteen days after common bile duct ligation. Thiobarbituric acid-reactive substances and lysosomal enzymes (beta-glucuronidase and acid phosphatase) were increased in the common bile duct ligated group as compared to the sham-operated group. The levels of antioxidant defense enzymes, superoxide dismutase, glutathione peroxidase, catalase and glutathione were decreased as compared to the sham-operated controls. Pre-operative vitamin E administration decreased mucosal lipid peroxidation increased the levels of antioxidant defense enzymes and lowered the lysosomal enzymes. The plasma vitamin E levels in this group were lower when compared to animals receiving it post-operatively. In conclusion, free radical and lysosomal enzyme mediated damage may play a role in portal hypertensive gastropathy.

Allopurinol and glutamine attenuate bacterial translocation in chronic portal hypertensive and common bile duct ligated growing rats

BACKGROUND

Spontaneous bacterial infections and septicaemia result in morbidity and mortality in patients with portal hypertension and obstructive jaundice.

AIM

The aim of this study in rats was to investigate the incidence of bacterial translocation in portal hypertension and obstructive jaundice, and to evaluate the effects of allopurinol and glutamine.

METHODS

Rats were subjected to sham laparotomy (SL), portal hypertension (PH) by calibrated stenosis of the portal vein, and common bile duct ligation (CBDL). Animals of each group were either treated with allopurinol (50 mg/kg twice a week), glutamine (1 g/kg/d), and allopurinol and glutamine.

RESULTS

After four weeks, significant bacterial translocation in the untreated PH and CBDL rats occurred. Intestinal mucosal malondialdehyde concentrations (MDA), as an indicator for lipid peroxidation, and myeloperoxidase activity (MPO) released from activated neutrophils were also significantly increased (p < 0.01). Allopurinol and glutamine in PH and CBDL rats improved bacterial translocation, and decreased MDA and MPO values (p < 0.01).

CONCLUSION

In PH and CBDL rats significant bacterial translocation, ileal mucosal lipid peroxidation, and neutrophil derived MPO activity occurred. Allopurinol and glutamine significantly reduced bacterial translocation, as well as ileal mucosal MDA and MPO activities.

Bacterial translocation in chronic portal hypertensive and common bile duct-ligated growing rats

Spontaneous bacteremias and infectious complications occur in patients with chronic portal hypertension (PH) and obstructive jaundice, and most of these infections are caused by indigenous intestinal bacteria translocating to regional lymph nodes and the systemic circulation. The aim of this study was to investigate bacterial translocation (BT) at two stages: (1) isolated chronic PH; and (2) obstructive jaundice. Four-week-old male rats were either subjected to sham laparotomy (SL) or to pH or common bile duct ligation (CBDL). After 4 weeks, animals were weighed and the portal pressure was measured. Samples from the portal vein (PV), vena cava, liver, spleen, mesenteric lymph nodes (MLN), and ileum were obtained for bacteriologic cultures. Specimens from the liver, jejunum, and ileum were taken for histologic examination. Portal pressure increased from 7.4±0.3 to 20.5±0.6 mmHg in PH and CBDL animals (P <0.01). Bacterial cultures obtained from the ileum showed significant bacterial overgrowth (P <0.01) in pH and CBDL rats (1.3±0.8 × 10(4) after SL; 1.2±0.6 × 10(5) in PH and 1.9±0.6 × 10(6) in CBDL). BT occured in 10% of SL animals to the MLN and spleen. In PH animals 23% positive cultures were found, almost all due to BT to the PV, vena cava, and liver. CBDL resulted in a BT rate of 47%, mainly by translocation to the PV, liver, and MLN (P <0.05 vs. SL). Histomorphologically, the jejunum and ileum were normal in all three groups. These results suggest that in growing PH and CBDL rats intestinal bacterial overgrowth with significant BT occurs, and the incidence of BT seems to be related to the amount of bacteria colonizing the intestinal tract.