Renal impairment following biliary tract surgery

Protective effects of intravenous anesthetics on kidney tissue in obstructive jaundice

AIM: To evaluate the protective effects on kidney tissue of frequently used intravenous anesthetics (ketamine, propofol, thiopental, and fentanyl) in rats with obstructive jaundice.

METHODS: There is an increased incidence of postoperative acute renal failure in patients with obstructive jaundice. Thirty-two Wistar-albino rats were randomly divided into four equal groups. Laparatomy was performed on each animal in the four groups and common bile ducts were ligated and severed on day 0. After 7 d, laparotomy was again performed using ketamine, propofol, thiopental, or fentanyl anesthesia whose antioxidative properties are well known in oxidative stress in a rat liver model of obstructive jaundice. After 2 h, the rats were sacrificed. Renal tissue specimens were analyzed for catalase, superoxide dismutase and malondialdehyde enzymes activities. All values are expressed as the mean ± SD. P values less than 0.05 were considered statistically significant.

RESULTS: All animals survived without complications until the end of the study. Enlargement in the bile duct and obstructive jaundice were observed in all rats. Catalase was found to be significantly lower in the fentanyl group than in the ketamine (P = 0.039), propofol (P = 0.012), and thiopental (P = 0.001) groups. Superoxide dismutase activities were similar in all groups (P > 0.05). Malondialdehyde was found to be significantly lower in the ketamine group than in the propofol (P = 0.028), thiopental (P = 0.002) and fentanyl (P = 0.005) groups. Malondialdehyde was also lower in the fentanyl group than in the thiopental group (P = 0.001). The results showed that obstructive jaundice sensitizes renal tissue to damage under the different anesthetics.

CONCLUSION: Among the agents tested, ketamine and propofol generated the least amount of oxidative stres on renal tissues in this rat model of obstructive jaundice created by common bile duct ligation. The importance of free radical injury in renal tissue in obstructive jaundice under different intravenous anesthetics during hepatobiliary and liver transplant surgery should be considered for prevention of postoperative acute renal failure.

Decreased hepatic peroxisome proliferator-activated receptor-γ contributes to increased sensitivity to endotoxin in obstructive jaundice

AIM: To investigate the role of hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) in increased susceptibility to endotoxin-induced toxicity in rats with bile duct ligation during endotoxemia.

METHODS: Male Sprague-Dawley rats were subjected to bile duct ligation (BDL). Sham-operated animals served as controls. DNA binding were determined by polymerase chain reaction, Western blotting analysis, and electrophoretic mobility shift assay, respectively. BDL and sham-operated rats received a non-lethal dose of intraperitoneal lipopolysaccharide (LPS) injection (3 mg/kg, i.p.). Additionally, the potential beneficial effects of the PPAR-γ agonist rosiglitazone were determined in BDL and sham-operated rats treated with a non-lethal dose of LPS. Survival was assessed in BDL rats treated with a non-lethal dose of LPS and in sham-operated rats treated at a lethal dose of LPS (6 mg/kg, i.p.).

RESULTS: PPAR-γ activity in rats undergoing BDL was significantly lower than in the sham-controls. Hepatic PPAR-γ gene expression was downregulated at both the mRNA and protein levels. In a parallel group, serum levels of pro-inflammatory cytokines were nearly undetectable in the sham-operated rats. When challenged with a non-lethal dose of LPS (3 mg/kg), the BDL rats had approximately a 2.4-fold increase in serum IL-6, a 2.7 fold increase in serum TNF-α, 2.2-fold increase in serum IL-1 and 4.2-fold increase in serum ALT. The survival rate was significantly lower as compared with that in sham-operated group. Additionally, rosiglitazone significantly reduced the concentration of TNF-α, IL-1β, IL-6 and ALT in sham-operated rats, but not in BDL rats, in response to LPS (3 mg/kg). Also, the survival was improved by rosiglitazone in sham-operated rats challenged with a lethal dose of LPS, but not in BDL rats, even with a non-lethal dose of LPS (3 mg/kg).

CONCLUSION: Obstructive jaundice downregulates hepatic PPAR-γ expression, which in turn may contribute to hypersensitivity towards endotoxin.

LPS-binding protein mediates LPS-induced liver injury and mortality in the setting of biliary obstruction

It is generally accepted that low levels of lipopolysaccharide (LPS)-binding protein (LBP) augment the cell's response to LPS, whereas high levels of LBP have been shown to inhibit cell responses to LPS. Clinical studies and in vitro work by our group have demonstrated that, in the setting of liver disease, increased or acute-phase levels of LBP may actually potentiate rather than inhibit an overwhelming proinflammatory response. Therefore, in the present studies we sought to determine the role of acute-phase LBP in mediating morbidity and mortality in animals challenged with LPS in the setting of biliary obstruction. Using LBP-deficient mice and LBP blockade in wild-type mice, we demonstrate that high levels of LBP are deleterious in the setting of cholestasis. Following biliary obstruction and intraperitoneal LPS challenge, hepatic injury, hepatic neutrophil infiltration, and mortality were significantly increased in animals with an intact LBP acute-phase response. Kupffer cell responses from these animals demonstrated a significant increase in several inflammatory mediators, and Kupffer cell-associated LBP appears to be responsible for these differences, at least in part. Our results indicate that the role of LBP signaling in inflammatory conditions is complex and heterogeneous, and elevated levels of LBP are not always protective. Increased LBP production in the setting of cholestatic liver disease appears to be deleterious and may represent a potential therapeutic target for preventing overwhelming inflammatory responses to LPS in this setting.

Altered Kupffer cell function in biliary obstruction

BACKGROUND

An altered Kupffer cell (KC) response is thought to be responsible for the characteristic phenotype observed after biliary obstruction: a phenotype marked by a defect in the hepatic reticuloendothelial system and a hypersensitivity to endotoxin. Few studies, however, have directly examined KC function. We have sought to define the specific alterations in function and phenotype that occur in the KC after biliary obstruction.

METHODS

KCs were isolated from female C57BL/6 mice 4 days after a sham or common bile duct ligation (CBDL) operation. Phagocytosis, oxidative burst potential, and intracellular bacterial killing were measured as markers of reticuloendothelial system function. The KC response to endotoxin was assessed by measuring tumor necrosis factor alpha and interleukin 6 levels in the media after stimulation with lipopolysaccharide (LPS) or with LPS plus LPS-binding protein (LBP).

RESULTS

CBDL KCs demonstrated a significant increase in phagocytic ability and significantly decreased baseline oxidative stress, compared with Shams. The oxidative burst potential, however, was equivalent or higher for CBDL KCs. CBDL KCs also demonstrated increased numbers of viable intracellular bacteria after infection; however, it is unclear if this finding represents impaired intracellular bacterial killing or increased phagocytosis of bacteria. With respect to the KC response to endotoxin, CBDL KCs were found to be less sensitive to the stimulatory effects of LPS alone but were exquisitely sensitive to the effects of LBP. LBP levels were found to be significantly elevated in CBDL animals, and CBDL KCs demonstrated a dose-dependent, exaggerated tumor necrosis factor alpha and interleukin 6 response to LPS administered with LBP.

CONCLUSIONS

KC function is clearly altered after biliary obstruction. Phagocytic ability is actually increased, although the ability of CBDL KCs to kill bacteria within the phagosome remains ill defined. CBDL KCs are exquisitely sensitive to the effects of LBP, and LBP levels are elevated after biliary obstruction. LBP may be responsible for the increased proinflammatory response observed after endotoxin challenge in animals with biliary obstruction.

Acute renal failure in the surgical setting

Acute renal failure (ARF) is an unwelcome complication of major surgical procedures that contributes to surgical morbidity and mortality. Acute renal failure associated with surgery may account for 18-47% of all cases of hospital-acquired ARF. The overall incidence of ARF in surgical patients has been estimated at 1.2%, although is higher in at-risk groups. Mortality of patients with ARF remains disturbingly high, ranging from 25% to 90%, despite advances in dialysis and intensive care support. Appreciation of at-risk surgical populations coupled with intensive perioperative care has the capacity to reduce the incidence of ARF and by implication mortality. Developments in understanding the pathophysiology of ARF may eventually result in newer therapeutic strategies to either prevent or accelerate recovery from ARF. At present the best form of treatment is prevention. In this review the epidemiology, pathophysiology, diagnosis, treatment and possible prevention of ARF will be discussed.

Liver and kidney diseases

The spectrum of renal disease in patients with liver disease is expanding. The recognition of renal complications of liver diseases is essential in the management of these patients. As liver transplantation is a treatment option for many patients with chronic liver disease, the presence of renal complications impacts the decision regarding transplantation and influences the course of these patients after transplantation, especially with regard to the use of immunosuppressive therapy. The involvement of the liver and kidney in systemic conditions is common and adds to the morbidity and mortality of patients.

Acute (ascending) cholangitis

Cholangitis is an infection of an obstructed biliary system, most commonly due to common bile duct stones. Bacteria reach the biliary system either by ascent from the intestine or by the portal venous system. Once the biliary system is colonized, biliary stasis allows bacterial multiplication, and increased biliary pressures enable the bacteria to penetrate cellular barriers and enter the bloodstream. Patients with cholangitis are febrile, often have abdominal pain, and are jaundiced. A minority of patients present in shock with hypotension and altered mentation. There is usually a leukocytosis, and the alkaline phosphatase and bilirubin levels are generally elevated. Noninvasive diagnostic techniques include sonography, which is the recommended initial imaging modality. Standard CT, helical CT cholangiography, and magnetic resonance cholangiography often add important information regarding the type and level of obstruction. Endoscopic sonography is a more invasive means of obtaining high-quality imaging, and endoscopic or percutaneous cholangiography offers the opportunity to perform a therapeutic procedure at the time of diagnostic imaging. Endoscopic modalities currently are favored over percutaneous procedures because of a lower risk of complication. Treatment includes fluid resuscitation and antimicrobial agents that cover enteric flora. Biliary decompression is required when patients do not rapidly respond to conservative therapy. Definitive therapy can be performed by a surgical, percutaneous, or endoscopic route; the last is favored because it is the least invasive and has the lowest complication rate. Overall prognosis depends on the severity of the illness at the time of presentation and the cause of the biliary obstruction.

Acute cholestasis-induced renal failure: effects of antioxidants and ligands for the thromboxane A2 receptor

BACKGROUND

Acute biliary obstruction is associated with the development of renal impairment and oxidative stress. The F2-isoprostanes, formed during oxidant injury, are renal vasoconstrictors acting via thromboxane (TX)-like receptors. We determined whether the formation of F2-isoprostanes is increased in experimental cholestasis and whether thiol containing antioxidants or ligands for the TXA2 receptor could improve renal function.

METHODS

The effects on renal function of acute bile duct ligation (BDL) in the rat were studied for two days. The consequences of administration of N-acetylcysteine (NAC), alpha-lipoic acid (LA), the TX receptor antagonist (TXRA) BAYu3405, or placebo were then examined.

RESULTS

BDL caused a reduction in creatinine clearance from 1.10 +/- 0.05 to 0.55 +/- 0.05 ml/min and sodium excretion from 52 +/- 3 to 17 +/- 3 micromol/hr. Urinary F2-isoprostanes increased from 14 +/- 2 to 197 +/- 22 pg/ml following BDL. Renal functional changes were ameliorated by NAC (creatinine clearance 0.73 +/- 0.05 ml/min), LA (0.64 +/- 0.03 ml/min), and a TXRA (0.90 +/- 0.15 ml/min); P < 0.05. Similarly, sodium excretion was increased from 17 +/- 3 micromol/hr (placebo) to 34 +/- 3 micromol/hr (NAC), 29 +/- 3 micromol/hr (LA), and 38 +/- 5 micromol/hr (TXRA); P < 0.005. Hepatic glutathione concentrations increased from 6.5 +/- 0.3 micromol/g (normal liver) to 8.8 +/- 0.5 micromol/g (NAC) and 7.7 +/- 0.3 micromol/g (LA), P < 0.01. However, only LA markedly inhibited F2-isoprostane formation (197 +/- 22 to 36 +/- 11 pg/ml creatinine clearance; P < 0.05). Urinary TXB2 excretion was elevated after BDL (2.2 +/- 0.5 to 111.1 +/- 20.3 pg/min) but was unaffected by NAC and LA.

CONCLUSION

NAC, LA, and TXRA can partially prevent renal dysfunction in experimental cholestasis. The effects of the antioxidants are independent of their ability to inhibit lipid peroxidation or TX synthesis.

Role of endotoxin and nitric oxide in the pathogenesis of renal failure in obstructive jaundice

BACKGROUND

There is an increased incidence of postoperative renal failure in patients with obstructive jaundice. The purpose of this study was to investigate the role of endotoxaemia and nitric oxide in this association.

METHODS

In bile duct-ligated, sham-operated and control rats, plasma total bilirubin levels, creatinine clearance and plasma endotoxin were determined. Endothelium-dependent vasodilatation to acetylcholine, and endothelium-independent vasodilatation to nitroglycerine and forskolin were evaluated in isolated perfused rat kidney.

RESULTS

Twenty-one of 27 bile-duct ligated rats had endotoxaemia. Plasma bilirubin levels were higher and creatinine clearance was significantly reduced in the bile duct-ligated endotoxin-positive group compared with values in the other groups. Furthermore, in the isolated perfused rat kidney from rats with endotoxaemia, basal perfusion pressure and renal vascular relaxation to acetylcholine and nitroglycerine which is mediated by guanosine cyclic 3',5'-cyclic monophosphate (cGMP) were significantly reduced, but relaxation to forskolin mediated by adenosine cyclic 3',5'-cyclic monophosphate did not change.

CONCLUSION

Endotoxaemia in obstructive jaundice may induce overproduction of nitric oxide that may lead to impairment of cGMP-associated vasodilatation and disrupt autoregulation of the renal vascular bed. This may contribute to renal failure in obstructive jaundice.

Intestinal barrier dysfunction in clinical and experimental obstructive jaundice and its reversal by internal biliary drainage

Intestinal mucosal barrier function in obstructive jaundice was assessed in an animal model and in patients. The effect of internal biliary drainage in patients was also examined. Bile duct ligation for 1 week in the rat resulted in significant bacterial translocation (in seven of 12 animals following ligation versus none of the shamoperated controls, P < 0.01). Intestinal permeability, measured by the urinary recovery of orally administered polyethylene glycol, was also significantly increased (+66.2 per cent for ligation versus -11.6 per cent for sham, P < 0.01). A prospective study was performed on 33 patients with obstructive jaundice undergoing internal biliary drainage, and results were compared with those in six non-jaundiced patients undergoing laparotomy or endoscopic retrograde cholangiopancreatography and in 11 health volunteers. The lactulose: mannitol ratio was used as an intestinal permeability index. Mean(s.e.m.) intestinal permeability assessed before operation was significantly increased in jaundiced patients compared with control patients (0.050(0.010) versus 0.016(0.003), P < 0.005). The mean(s.e.m.) lactulose: mannitol ratio in the healthy volunteers was 0.020(0.003), which was similar to that in control patients. In the jaundiced group of patients the intestinal permeability index fell to within normal levels after 28 days of internal biliary drainage (0.050 before operation versus 0.021 at 28 days, P < 0.02). These data indicate that intestinal barrier function is impaired in obstructive jaundice and that this impairment is reversed by return of bile to the gastrointestinal tract.

Renal dysfunction in obstructive jaundice

The association between renal dysfunction and obstructive jaundice is well established. Despite a substantial number of clinical reviews and prospective studies, the exact incidence and extent of the problem has not been determined accurately. Various pathogenic mechanisms and therapeutic strategies have been proposed but renal dysfunction remains a persistent problem in hepatobiliary practice. The intention of this review is to determine the current extent of the problem, outline the proposed pathophysiological mechanisms and assess the current therapeutic options.

Hepatic functional reserve in patients with obstructive jaundice: an assessment by the redox tolerance test

PURPOSE

Hepatic mitochondrial response to oral glucose load (redox tolerance test) was evaluated as an indicator of hepatic functional reserve of patients with obstructive jaundice.

PATIENTS AND METHODS

The redox tolerance test was performed in 29 patients with obstructive jaundice before percutaneous transhepatic biliary drainage and 2 weeks after the procedure.

RESULTS

The redox tolerance index (RTI) before drainage was not related to conventional parameters other than albumin, but was significantly associated with bilirubin half-life (P < 0.01). Of 19 patients with an RTI > or = 0.5 before drainage, all maintained similar values after drainage and experienced satisfactory clinical courses, even after major surgery. Of 10 patients with an RTI < 0.5 before drainage, 5 showed improvement and 5 deteriorated after drainage. Four of the latter 5 died within 60 days after drainage. The hospital mortality was significantly greater in patients with initial RTI < 0.5 than in patients with RTI > or = 0.5 (P < 0.01).

CONCLUSION

The redox tolerance test is useful for evaluating hepatic functional reserve and prognosis in patients with obstructive jaundice.

Aminoglycoside-associated nephrotoxicity in extrahepatic obstructive jaundice

Experimental data demonstrate that biliary obstruction increases renal sensitivity to gentamicin. In the present study the incidence of and risk factors for aminoglycoside nephrotoxicity were prospectively studied in patients with extrahepatic obstructive jaundice. Two hundred and thirty-seven hospitalized adult patients were classified into three groups. Group I consisted of 84 patients with extrahepatic obstructive jaundice, who received aminoglycoside (gentamicin or tobramycin). Group II consisted of 81 patients with extrahepatic obstructive jaundice, who received either antibiotics other than aminoglycoside or no antimicrobial therapy. Group III consisted of 72 noncholestatic patients receiving aminoglycosides for different disorders. Nephrotoxicity developed in 27 patients (32%) in group I vs 9 patients (11%) in group II and 4 patients (5.6%) in group III (p < 0.00001). In group I, a comparison of patients with and without nephrotoxicity revealed significantly higher values in the former for mean serum bilirubin concentration, initial steady-state trough aminoglycoside concentration and estimated half-life. Stepwise multivariate analysis with nephrotoxicity status as the dependent variable determined that the most significant variable for predicting nephrotoxicity was serum total bilirubin level. In extrahepatic cholestasis a high serum bilirubin level is a distinct factor predisposing to aminoglycoside nephrotoxicity.

Improvements in survival by aggressive resections of hilar cholangiocarcinoma

The operative management of hilar cholangiocarcinoma has evolved because of advances in diagnostic imaging that have permitted improved patient selection, and refinements in operative techniques that have lowered operative mortality rates. Over a 4-year period, 48 patients with hilar cholangiocarcinoma were managed. Twenty-seven patients were treated by palliative measures. Preoperative investigation identified 29 patients who were judged fit for operation without proven irresectability by radiologic studies, and 21 of the 29 patients had tumor removal (72%). Twenty-three operative procedures were performed: local excision (n = 12) (two had subsequent hepatic resection), and hepatic resection primarily (n = 9). Eight patients had complications (35%), and one patient died (4.3%). The mean actuarial survival after local excision in 36 months, and after hepatic resection, 32 months. Palliation as assessed by personal interview was excellent for more than 75% of the months of survival. A combination of careful patient selection and complete radiologic assessment will allow an increased proportion of patients to be resected by complex operative procedures with low mortality rate, acceptable morbidity rate, and an increase in survival with an improved quality of life.

Factors affecting morbidity and mortality in biliary tract surgery

Thirty-six clinical and laboratory parameters in 770 consecutive patients undergoing biliary tract surgery over a 3 year period were analyzed in an effort to define the patients at greatest risk. Twelve parameters had a significant correlation with hospital mortality, while multivariate analysis revealed that septic shock, malignant obstruction, serum albumin less than 3.0 gm%, history of hypertension, and plasma urea nitrogen greater than 20 mg% had an independent significance in predicting postoperative mortality. The presence of more than 2 of these risk factors identified a group of patients with an 18% mortality rate. It is for this group of patients that adequate pre-operative preparation such as fluid resuscitation, prophylactic antibiotics, and nutritional support are essential. The controversial preoperative biliary drainage might be only indicated in this group of patients.

Surgical morbidity and mortality in one hundred and twenty-nine patients with obstructive jaundice

One hundred and twenty-nine jaundiced patients were operated upon for the relief of benign and malignant bile duct obstruction during a 10-year period, 1977-86. The overall mortality was 4.7 per cent but increased to 9.1 per cent in patients with a serum bilirubin greater than 300 mumol/l. In all, 46.5 per cent of patients had a rise in postoperative creatinine but renal dysfunction occurred in only 4.7 per cent. Wound infection developed in 3.1 per cent of patients and appeared unrelated to infected bile; 3.9 per cent of patients were treated for postoperative septicaemic episodes. The low morbidity and mortality observed suggests that preoperative biliary drainage need not be considered in routine surgical practice if simple measures to maintain urine flow and prevent postoperative sepsis are used.