Impaired hepatic bacterial clearance is reversed by surgical relief of obstructive jaundice

The alterations in hepatic microcirculation and Kupffer cell activity after biliary drainage in jaundiced mice

BACKGROUND/PURPOSE

The aim of this study is to examine the effects of biliary drainage on hepatic microcirculation and Kupffer cell activity in the liver with obstructive jaundice.

METHODS

Common bile duct ligation and division was performed on C57BL/6 mice to induce obstructive jaundice. Seven or 14 days after surgery, some mice underwent biliary drainage. Three days after biliary drainage, sinusoidal perfusion, leukocyte rolling and sticking in the postsinusoidal venules, and the diameters of sinusoids containing blood flow were evaluated using intravital microscopy. Kupffer cell phagocytic activity was estimated as the ratio of Kupffer cells that phagocytosed fluorescent-labeled particles to sinusoids containing blood flow.

RESULTS

Sinusoidal perfusion after biliary drainage was significantly increased compared with that in livers with obstructive jaundice, but remained decreased compared with controls. Although the number of rolling leukocytes and sticking leukocytes was significantly decreased, the diameters of sinusoids remained reduced, associated with an increase in Kupffer cell phagocytic activity compared with controls even after biliary drainage.

CONCLUSIONS

Leukocyte-endothelial cell interaction is ameliorated but sinusoids remain narrowed due to swelling of activated Kupffer cells; this might cause deterioration of hepatic microcirculation during the early phase of biliary drainage.

Percutaneous transhepatic biliary drainage

Over the past three decades, endoscopic and percutaneous biliary drainage have become readily available in most hospital settings and these minimally invasive techniques have revolutionized the treatment of patients with biliary obstruction. In the past, treatment of biliary obstruction had required surgery under general anesthesia and an extended hospital stay. Currently, the same patient can most often be treated either endoscopically as an outpatient or during a short hospital stay after percutaneous drainage under moderate sedation. This article reviews the indications and technique of percutaneous transhepatic cholangiography and biliary drainage.

Role of Kupffer cells in the infection of biliary tract

Acute infection of biliary tract was a frequent severe case in hepatobiliary surgery and also a common cause of sepsis, multiple organ system failure (MOSF) and even death. The biliary system could suppress infection through physical, chemical and immune mechanisms. Kupffer cell (KC) is an important ingredient of the monocyte-phagocyte system and also a natural barrier against the infection of biliary tract, thus plays an important role both in the development and prevention of biliary tract infection. How to regulate the function of Kupffer cells and prevent multiple organ system failure in biliary duct infection are the most important problems to be solved.

A new technique of biliary reconstruction after "high hilar resection" of hilar cholangiocarcinoma with tumor extension to secondary and tertiary biliary radicals

BACKGROUND

Radical operation for hilar cholangiocellular carcinoma, including extended hepatic resection, seems to improve prognosis by increasing the surgical curability rate. Nevertheless, high postoperative morbidity and mortality have been reported in patients with obstructive jaundice. We describe the technique of "high hilar resection" and a modification of bilioenteric anastomosis for drainage of the multiple secondary or tertiary biliary radicals.

METHODS

Ten patients with advanced hilar cholangiocellular carcinoma underwent a high hilar resection with complete parenchymal preservation, and the biliary drainage was reconstructed by a sheath-to-enteric hepaticojejunostomy. Because of the technical difficulty caused by anastomosis line in the range of the biliary sheath, a modification was performed by dividing the biliary apertures of segments 5 and 4b.

RESULTS

A high hilar resection was successfully performed, and all patients were discharged from the hospital in good condition. No patient died postoperatively. The proximal resection margin was tumor-free in all patients. One patient died after 29 months of peritoneal carcinomatosis. None of the patients developed local recurrence around the hepaticojejunostomy. The remaining nine patients are alive after a mean follow-up of 28.8 months after surgery without any signs of recurrence.

CONCLUSION

In highly selected patients with advanced hilar cholangiocellular carcinoma, a high hilar resection is technically safe and oncologically justifiable. In combination with our new technique of sheath-to-enteric anastomosis, the patients considerably benefit from the preservation of liver parenchyma with low postoperative morbidity and very short in-hospital stay.

Reversible cholestasis and cholangitis induced by biliary drainage and infusion in the rat

To develop a rat model of ascending cholangitis, we constructed a controllable and accessible biliary drainage and infusion system. We first modified a reversible cholestasis model of the rat and then induced ascending cholangitis by administration of Escherichia coli into the proximal choledochostomy tube. After biliary infusion of E. coli, the liver, choledochostomy tube and bile were all positive for E. coli, but no bacteria grew in rats receiving biliary infusion of normal saline. Retrograde cholangiography of the initial choledochostomy ensured that the tube end was in the right position in the proximal common bile duct. The patency of the tube-tube choledochocholedochostomy was confirmed by a cholangiogram on day 90. Thirty days after the tube-tube choledochocholedochostomy, the livers of the experimental animals did not differ from the control livers. The tube-tube choledochocholedochostomy model not only provides reproducible, reliable, reversible cholestasis, but creates a sustainable and accessible biliary infusion system. This can be used for long-term investigations of repeated cholangitis and recurrent cholestasis.

Effect of 5-lipoxygenase inhibition on Kupffer cell clearance capacity in obstructive jaundiced rats

BACKGROUND

Obstructive jaundice is a common surgical problem. It may cause hepatic and Kupffer cell dysfunction. Previous studies demonstrated that 5-lipoxygenase inhibition prevents hepatic injury. However, its effect on Kupffer cell clearance capacity has not been determined yet.

MATERIALS AND METHODS

Rats were divided into four groups. In group 1 (sham control group), only bile duct dissection was performed. In other groups bile ducts were ligated and divided. In groups 1 and 2 saline, in group 3 ethanol, and in group 4 a 5-lipoxygenase inhibitor AA-861 was given intraperitoneally to the animals. Rats were sacrificed 14 days after the operations. Serum alkaline phosphatase, total bilirubin, and alanine aminotransferase levels were determined. Kupffer cell clearance capacity was measured using an in situ isolated hepatic perfusion technique. Hematoxylin-eosin-stained liver samples were evaluated under light microscope for histopathologic scoring.

RESULTS

Rats in the sham control group had significantly lower serum ALP and bilirubin values than those in the experimental groups with biliary obstruction. AA-861 administration significantly decreased serum ALT levels and histopathologic scores. There was no significant difference in ALT levels and histopathologic scores between the sham control and AA-861 groups. Kupffer cell clearance capacity was found to be significantly increased in the AA-861 group compared to other experimental groups with obstructive jaundice.

CONCLUSIONS

This study shows that leukotriene synthesis inhibition using AA-861 prevents hepatic damage and improves Kupffer cell clearance capacity in obstructive jaundiced rats. This may have significant implications for the management of patients with obstructive jaundice.

Biliary atresia. A surgical perspective

The combination of portoenterostomy with subsequent liver transplantation is the treatment of choice for patients with biliary atresia. It is important, however, to attempt to keep the patient's own organ by continuing efforts to achieve the best possible results with portoenterostomy. Additional basic research, perhaps concerning on the role of cytokines and apoptosis in the control of biliary atresia, may provide insight into possible new medical strategies for treating patients with biliary atresia. For example, in addition to portoenterostomy, control of apoptosis at various cellular levels and of bile duct cell proliferation and maturation by manipulation of the growth factors and cytokines may become part of future treatment modalities. Another direction of research should be the control of fibrogenesis, which might be accomplished by blocking TGF-beta 1 and platelet-derived growth factor and by HGF gene therapy. The author's current strategy for surgical treatment for patients with biliary atresia include (1) early diagnosis, including prenatal diagnosis and broader use of mass screening programs, (2) hepatic portoenterostomy, without stoma formation; (3) close postoperative care, especially for prevention of postoperative cholangitis; (4) revision of portoenterostomy only in selected cases; (5) early liver transplantation in patients with absolutely failed portoenterostomy; (6) avoidance of laparotomy for the treatment of esophageal varices and hypersplenism; (7) consideration of exploratory laparotomy or primary liver transplantation for patients with advanced liver disease at the time of referral. The development of new treatment modalities based on the understanding of the pathogenesis of the disease, and especially on the biology of intrahepatic bile ducts and hepatic fibrosis, is essential.

Dexamethasone coupled to albumin is selectively taken up by rat nonparenchymal liver cells and attenuates LPS-induced activation of hepatic cells

BACKGROUND/AIMS

The human serum albumin (HSA) conjugate Dexa10-HSA was designed to specifically deliver the anti-inflammatory drug dexamethasone (Dexa) to nonparenchymal cells (NPC) in the rat liver. NPC play an important role in the pathogenesis of acute and chronic inflammatory liver diseases like fibrosis. Targeting Dexa to these cells might reduce its adverse effects and increase the efficacy.

METHODS

Tissue and intrahepatic distributions of Dexa10-HSA were assessed in normal and fibrotic rats with 125I-labelled conjugate and by immunohistochemistry. The effect of the conjugate on lipopolysaccharide (LPS)-induced inflammation and cell activation was studied in vitro with precision-cut liver slices and in vivo.

RESULTS

Ten minutes after i.v. injection 72+/-13% and 65+/-12% of a tracer dose of Dexa10-HSA had been taken up in normal and fibrotic livers, respectively. Unconjugated Dexa also accumulated in livers, but cellular distribution studies revealed an accumulation in parenchymal cells (NPC vs. parenchymal cell (PC) ratio=0.29+/-11, p<0.005) whereas Dexa10-HSA accumulated in nonparenchymal cells (NPC/PC ratio=7.9+/-3.1). Both coupled and uncoupled Dexa showed effective inhibition of LPS-induced NOx and TNFalpha production in precision-cut liver slices. At low concentrations (0.02 microM), however, Dexa10-HSA was more efficient at inhibiting TNFalpha production than uncoupled Dexa. In fibrotic rats Dexa10-HSA (3 mg/kg) and an equimolar amount of uncoupled Dexa (0.22 mg/kg) both significantly promoted survival after LPS-induced acute inflammation.

CONCLUSION

Dexa10-HSA was at least as effective as uncoupled Dexa at inhibiting LPS-induced effects, which indicates that HSA-bound Dexa is pharmacologically active. Coupling Dexa to HSA shifted the accumulation of Dexa from the PC to the NPC of livers. Since mediator release from NPC is crucial in the initiation and propagation of the fibrotic process, selective delivery of Dexa in NPC may improve the efficacy and safety of corticosteroid treatment of liver fibrosis.

Bacterial translocation from the biliary tract to blood and lymph in rats with obstructive jaundice

BACKGROUND

The disruption of the hepatocyte tight junctions observed in biliary obstruction suggests altered permeability of the blood-bile barrier. In this study the role of biliary obstruction and increased biliary pressure on the translocation of bacteria from biliary tract to bloodstream and lymphatic system were evaluated.

MATERIALS AND METHODS

Rats underwent distal bile duct ligation (BDL, n = 33) for two weeks or a sham celiotomy (n = 21). Seventeen of the 33 BDL rats underwent subsequent biliary decompression by a choledochojejunostomy (CJ). Two weeks after the final operation, a laparotomy was performed again and the CBD, the thoracic duct, and the caval vein were canulated. Next, a suspension containing 10(8) Escherichia coli/ml was retrogradely infused in the CBD for 5 min at 5 or 20 cm H2O above the secretory biliary pressure.

RESULTS

A higher biliary infusion pressure resulted in a significant increase of cfu E.coli per milliliter of blood in all the three groups (Sham, BDL, CJ). BDL rats showed significantly more bacterial translocation to the bloodstream than the shams. After biliary decompression, translocation normalized to the control levels. At 5 cm H2O infusion pressure only one lymph culture was positive (CJ group). At 20 cm H2O overpressure, nine lymph cultures were E.coli positive (P = 0.03). These were found mainly in groups with a nonobstructed bile duct (Sham and CJ 40% vs BDL 10%).

CONCLUSION

Translocation of bacteria from biliary tract to bloodstream increased at higher intrabiliary pressures. Longstanding bile duct obstruction was an independent determinant for cholangiovenous reflux. Bacterial translocation to the lymphatic system did not parallel translocation to the bloodstream, although in the nonobstructed biliary tract, increased bacterial translocation to the lymphatic system was pressure related.

Biliary decompression promotes Kupffer cell recovery in obstructive jaundice

BACKGROUND

Jaundiced patients undergoing surgical procedures have an increased risk of Gram negative sepsis with potential morbidity and mortality. Depressed Kupffer cell clearance capacity (KCCC) predisposes jaundiced patients to endotoxaemia and its sequelae. Biliary decompression remains the main therapeutic strategy in obstructive jaundice.

AIMS

This study investigates the efficacy of internal (ID) and external biliary drainage (ED) on KCCC in an experimental model of extrahepatic biliary obstruction.

METHODS

Adult male Wistar rats (250-300 g) were assigned to one of six groups: sham operated, where the bile duct was mobilised but not divided; bile duct ligation (BDL) for three weeks, and sham operated or BDL for three weeks followed by a second laparotomy and further 21 days of ID or ED, by way of choledochoduodenostomy or choledochovesical fistula respectively. KCCC was measured using an isolated hepatic perfusion technique with FITC labelled latex particles (0.75 mu) as the test probe. Plasma was assayed for bilirubin, endotoxin, and anticore glycolipid antibody (ACGA) concentrations.

RESULTS

Jaundiced rats had reduced KCCC (p < 0.001), increased concentrations of ACGA (p < 0.001), and endotoxin (p < 0.001) compared with controls. Biliary drainage for three weeks produced a recovery in KCCC and normalisation of endotoxin and ACGA concentrations, however, external drainage was less effective than ID (p < 0.01).

CONCLUSIONS

These data support the hypothesis that endotoxaemia and its mediated effects are integral in the pathophysiology of jaundice. Furthermore, a short period of internal biliary drainage is a useful therapeutic strategy in restoring Kupffer cell function and negating systemic endotoxaemia and consequent complications in biliary obstruction.

Effects of chemically defined structured lipid emulsions on reticuloendothelial system function and morphology of liver and lung in a continuous low-dose endotoxin rat model

BACKGROUND

This study was undertaken to determine the effect of chemically defined structured lipids on nonspecific host defense and on histologic patterns of liver and lungs compared with a physical mixture of long-chain triglycerides and medium-chain triglycerides in a continuous low-dose endotoxin rat model.

METHODS

Forty male Sprague-Dawley rats, divided into four feeding groups (structured lipids, structured lipids+endotoxin, physical mixture, physical mixture+endotoxin), received total parenteral nutrition for 48 hours. During the first part of the study, 24 animals were given an injection of live Escherichia coli labeled with radioactive iron (59Fe) to investigate the function of the reticuloendothelial system. During the second part of the study, the liver and lungs of 16 animals were histologically examined using light and electron microscopy.

RESULTS

Despite the similar values in the control groups, the animals receiving structured lipids+endotoxin sequestered a significantly greater percentage of bacteria in the liver and spleen (p < or = .01) and a significantly lesser percentage in the lung (p < or = .05) compared with the animals given physical mixture+endotoxin as part of their diet. Moreover, rats in the physical mixture+endotoxin group showed a microscopically evaluated higher fatty infiltration in the liver than did the structured lipids+endotoxin group.

CONCLUSIONS

The results of this study indicate that chemically defined structured lipids reduce fatty infiltration of the liver compared with a physical mixture of the same compounds in an animal model of metabolic stress. They were accompanied by a better function of the reticuloendothelial system and a lesser bacterial sequestration in the lungs.

Distribution of free and liposome-encapsulated cefoxitin in experimental intra-abdominal sepsis in rats

The distributions of radiolabelled free cefoxitin (FC) and liposome-encapsulated cefoxitin (LC) were compared in an animal model of intra-abdominal sepsis. Intraperitoneally administered LC was initially retained in the peritoneal cavity with subsequent preferential drug targeting to the liver (14% injected LC) and spleen (6% injected LC) by 3 h post-injection. Differing patterns of liposomal drug and lipid retention indicated that drug release from the liposome complex occurred within the peritoneum, liver and spleen. Intraperitoneal FC was rapidly taken up into the systemic circulation, with peak recovery in the blood (9% injected FC) and liver (5% injected FC) at 1 h post-injection. FC was also rapidly eliminated; 7% of the injected drug was recovered in the kidney 1 h post-injection. A negligible amount of FC was recovered in the spleen and very little FC or LC was found in the lungs of treated animals. Unlike FC, LC was found to provide a sustained bactericidal drug level (> 40 micrograms mL-1) in the peritoneal fluid for up to 5 h post-injection. LC also achieved significantly higher drug levels, compared with FC, within the liver at 3 and 5 h post-injection. Since severe intra-abdominal sepsis is often characterized by the presence of intraphagocytic bacteria in hepatic and splenic reticuloendothelial systems, the enhanced delivery of liposome-encapsulated anti-microbial agents, such as cefoxitin, to the liver and spleen may provide a more effective treatment for the septic condition.

Impaired clearance and organ localization of Candida albicans in obstructive jaundice

Sepsis is a major cause of morbidity and mortality in infants with cholestatic jaundice. This may be attributed to altered host defense mechanisms. Fungal infection frequently occurs in immunocompromised patients. This study evaluates the effect of biliary obstruction on blood clearance and organ localization of radiolabeled viable Candida albicans. Male Sprague-Dawley rats (140 to 150 g) were placed in 2 groups. Group I (n = 30) were sham-operated controls. Group II (n = 90) underwent ligation and division of the distal common bile duct (CDL). At 1, 2, and 3 weeks following CDL, 10(7) cells/mL radiolabeled viable C albicans were injected via the tail vein. The final distribution of the organisms was calculated and expressed as the mean percent of radiolabeled organisms per gram and per total organ. Blood clearance of C albicans was similarly rapid in both groups. However, there was a significant decrease in the trapping of fungi by the rat liver Kupffer cells (20.3% +/- 7.9% v control 42.5% +/- 15%; P greater than .001), and increased pulmonary localization of bacteria 3 weeks following CDL (53.6% +/- 13.2% v control 41.4% +/- 6.4%). The significant decrease in liver trapping and increased lung localization of C albicans in CDL rats, may result in systemic reemergence of fungi and play a role in the susceptibility to fungal infection in jaundiced subjects.

Intralipid adversely affects reticuloendothelial bacterial clearance

Lipid emulsion is a major caloric source in patients receiving total parenteral nutrition. Cleared by the Kupffer cells of the reticuloendothelial system (RES), lipid emulsion may adversely affect the RES function by decreasing its ability to remove blood-borne bacteria. This study evaluates and compares the blood clearance and organ localization of viable radiolabeled [35S] Escherichia coli following slow intraperitoneal (IP) and more rapid intravenous (IV) administration of a 20% fat emulsion (FE). Sixty male Sprague-Dawley rats weighing 150 g were placed in 6 experimental groups (10 rats per group). Group 1 received IP normal saline (3 mL/d for 3 days); group II received IP FE (20%) (4 g/kg/d for 3 days); and group III received normal saline IV (3 mL/d for 3 days). The remaining animals received a slow (15-minute) IV infusion of FE (4 g/kg/dose) prior to bacterial challenge: group IV at 4 hours; group V at 24 hours; and group IV at 4 and 24 hours. E coli (10(9)/mL) were injected via the tail vein. Blood samples were obtained for clearance study. At 10 minutes, tissue samples (50 to 100 mg) of liver, spleen, kidney, and lung were obtained and processed for liquid scintillation counting. Although rapid bacterial blood clearance was found in all the groups, there was a significant change in organ localization of bacteria. Normal distribution of bacteria in group I was as follows: liver 70.1% +/- 6.2%, spleen 5.2% +/- 1.2%, kidney 0.2% +/- 0.04%, and lung 1.6% +/- 0.6%. There was a slight increase in lung localization of bacteria in rats receiving IP FE (3.7% +/- 1.5%; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)