Multimodal decoding of human liver regeneration.

The liver has a unique ability to regenerate1,2; however, in the setting of acute liver failure (ALF), this regenerative capacity is often overwhelmed, leaving emergency liver transplantation as the only curative option3-5. Here, to advance understanding of human liver regeneration, we use paired single-nucleus RNA sequencing combined with spatial profiling of healthy and ALF explant human livers to generate a single-cell, pan-lineage atlas of human liver regeneration. We uncover a novel ANXA2+ migratory hepatocyte subpopulation, which emerges during human liver regeneration, and a corollary subpopulation in a mouse model of acetaminophen (APAP)-induced liver regeneration. Interrogation of necrotic wound closure and hepatocyte proliferation across multiple timepoints following APAP-induced liver injury in mice demonstrates that wound closure precedes hepatocyte proliferation. Four-dimensional intravital imaging of APAP-induced mouse liver injury identifies motile hepatocytes at the edge of the necrotic area, enabling collective migration of the hepatocyte sheet to effect wound closure. Depletion of hepatocyte ANXA2 reduces hepatocyte growth factor-induced human and mouse hepatocyte migration in vitro, and abrogates necrotic wound closure following APAP-induced mouse liver injury. Together, our work dissects unanticipated aspects of liver regeneration, demonstrating an uncoupling of wound closure and hepatocyte proliferation and uncovering a novel migratory hepatocyte subpopulation that mediates wound closure following liver injury. Therapies designed to promote rapid reconstitution of normal hepatic microarchitecture and reparation of the gut-liver barrier may advance new areas of therapeutic discovery in regenerative medicine.

Neutrophil gelatinase-associated lipocalin is a biomarker of acute-on-chronic liver failure and prognosis in cirrhosis.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF. METHODS: We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF. RESULTS: Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)µg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001). CONCLUSIONS: NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome. LAY SUMMARY: Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.

Ornithine phenylacetate targets alterations in the expression and activity of glutamine synthase and glutaminase to reduce ammonia levels in bile duct ligated rats.

BACKGROUND & AIMS: In liver failure, ammonia homeostasis is dependent upon the function of the ammonia metabolising enzymes, glutamine synthetase (GS) and glutaminase (GA) but data about their protein expression and activity are lacking. The aims of this study were to determine the protein expression and activity of GS and GA in individual organs in a rat model of chronic liver disease and to test whether the treatment with the ammonia-lowering agent ornithine phenylacetate (OP) modulates their activities. METHODS: 49 SD rats were studied 35 days after sham-operation or bile duct ligation (BDL). The BDL group received: L-ornithine (0.6 mg/kg/day), Phenylacetate (0.6 mg/kg/day), OP (0.6 mg/kg/day) or placebo (saline) for 5 days prior to sacrifice. Arterial ammonia, amino acids and liver biochemistry were measured. Expressions of GS and GA were determined by Western-blotting and activities by end-point methods in liver, muscle, gut, kidney, lung, and frontal cortex. RESULTS: In BDL rats, hepatic GS enzyme activity was reduced by more than 80% compared to sham rats. Further, in BDL rats GA activity was reduced in liver but increased in the gut, muscle and frontal cortex compared to sham rats. OP treatment resulted in a reduction in hyperammonemia in BDL rats, associated with increased GS activity in the muscle and reduced gut GA activity. CONCLUSIONS: In a rat model of chronic liver failure, hyperammonemia is associated with inadequate compensation by liver and muscle GS activity and increased gut GA activity. OP reduces plasma ammonia by increasing GS in the muscle and reducing GA activity in the gut providing additional insights into its mechanism of its action. GS and GA may serve as important future therapeutic targets for hyperammonemia in liver failure.

Dogs with congenital porto-systemic shunting (cPSS) and hepatic encephalopathy have higher serum concentrations of C-reactive protein than asymptomatic dogs with cPSS.

Hepatic encephalopathy (HE) is a cause of significant morbidity and mortality in patients with liver disorders and a wide range of rodent models of HE have been described to facilitate studies into the pathogenesis and treatment of HE. However, it is widely acknowledged that no individual model perfectly mimics human HE and there is a particular need for spontaneous, larger animal models. One common congenital abnormality in dogs is the portosystemic shunt (cPSS) which causes clinical signs that are similar to human HE such as ataxia, disorientation, lethargy and occasionally coma. As inflammation has recently been shown to be associated with HE in humans, we hypothesised that inflammation would similarly be associated with HE in dogs with cPSS. To examine this hypothesis we measured C-reactive protein (CRP) in 30 healthy dogs, 19 dogs with a cPSS and no HE and 27 dogs with a cPSS and overt HE. There was a significant difference in CRP concentration between healthy dogs and dogs with HE (p < 0.001) and between dogs with HE and without HE (p < 0.05). The novel finding that there is an association between inflammation and canine HE strengthens the concept that HE in dogs with cPSS shares a similar pathogenesis to humans with HE. Consequently, dogs with a cPSS may be a good spontaneous model of human HE in which to further examine the role of inflammation and development of HE.

Acute endotoxemia following transjugular intrahepatic stent-shunt insertion is associated with systemic and cerebral vasodilatation with increased whole body nitric oxide production in critically ill cirrhotic patients.

BACKGROUND & AIMS: Transjugular intrahepatic stent-shunt (TIPSS) insertion, in patients with uncontrolled gastro-intestinal bleeding, often results in worsening of the systemic hemodynamics which can be associated with intracranial hypertension but the underlying mechanisms are unclear. This study explored the hypothesis that TIPSS insertion results in acute endotoxemia which is associated with increased nitric oxide production resulting in systemic and cerebral vasodilatation. METHODS: Twelve patients with cirrhosis who were undergoing TIPSS for uncontrolled variceal bleeding were studied prior to and 1-h after TIPSS insertion. Changes in cardiac output (CO) and cerebral blood flow (CBF) were measured. NO production was measured using stable isotopes using l-[guanidino-(15)N(2)] arginine and l-[ureido-(13)C;5,5-(2)H(2)] citrulline infusion. The effect of pre- and post-TIPSS plasma on nitric oxide synthase (NOS) activity on human endothelial cell-line (HUVEC) was measured. RESULTS: TIPSS insertion resulted in a significant increase in CO and CBF. Endotoxin and induced neutrophil oxidative burst increased significantly without any significant changes in cytokines. Whole body NO production increased significantly and this was associated with increased iNOS activity in the HUVEC lines. The change in NO production correlated with the changes in CO and CBF. Brain flux of ammonia increased without significant changes in arterial ammonia. CONCLUSIONS: In conclusion, the insertion of TIPSS results in acute endotoxemia which is associated with increased nitric oxide production possibly through an iNOS dependent mechanism which may have important pathophysiological and therapeutic relevance to understanding the basis of circulatory failure in the critically ill cirrhotic patient.

L-Ornithine phenylacetate (OP): a novel treatment for hyperammonemia and hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common neuropsychiatric complication of liver disease affecting about 20-30% patients with cirrhosis. HE may only affect quality of life (e.g. impairments in attention; coordination; driving ability), but in some patients this progresses to coma and death; defining mortality in those with acute liver failure. HE is thought to occur through accumulation of ammonia as a by-product of protein metabolism. In liver failure ammonia accumulates to toxic levels, resulting in ammonia-associated brain swelling. Presently, there is no proven therapy for HE though recent studies suggest that during liver failure, ammonia removal by skeletal muscle (by conversion to glutamine) can be manipulated; also that ammonia and amino acid metabolism should be viewed in terms of their interorgan relationship. This led us to develop a novel concept for ammonia removal. Preliminary studies provide the proof of concept that the combination of L-ornithine (amino acid) with phenylactetate, as L-ornithine phenylacetate (OP), reduces toxic levels of ammonia by (1) L-ornithine acting as a substrate for glutamine synthesis from ammonia in skeletal muscle and (2) phenylacetate excreting the ornithine-related glutamine as phenylacetylglutamine in the kidneys. As both L-ornithine and phenylacetate are already available for human use, data showing its usefulness in ammonia lowering could translate quickly into providing the much needed therapy for HE patients.

Post-Transcriptional Regulation of Hepatic DDAH1 with TNF Blockade Leads to Improved eNOS Function and Reduced Portal Pressure In Cirrhotic Rats.

Portal hypertension (PH) is a major cause of morbidity and mortality in chronic liver disease. Infection and inflammation play a role in potentiating PH and pro-inflammatory cytokines, including TNF, are associated with severity of PH. In this study, cirrhotic bile duct ligated (BDL) rats with PH were treated with Infliximab (IFX, a monoclonal antibody against TNF) and its impact on modulation of vascular tone was assessed. BDL rats had increased TNF and NFkB compared to sham operated rats, and their reduction by IFX was associated with a reduction in portal pressure. IFX treatment also reduced hepatic oxidative stress, and biochemical markers of hepatic inflammation and injury. IFX treatment was associated with an improvement in eNOS activity and increased L-arginine/ADMA ratio and DDAH1 expression. In vitro analysis of HepG2 hepatocytes showed that DDAH1 protein expression is reduced by oxidative stress, and this is in part mediated by post-transcriptional regulation by the 3'UTR. This study supports a role for the DDAH1/ADMA axis on the effect of inflammation and oxidative stress in PH and provides insight for new therapies.

Early invasive fungal infections and colonization in patients with cirrhosis admitted to the intensive care unit.

Bacterial infections in cirrhosis are common and associated with increased mortality, but little is known about fungal infections. The aim of this study, a sub-analysis of the Fungal Infection Risk Evaluation study, was to assess the incidence and implications of early invasive fungal disease (IFD) in patients with cirrhosis admitted to intensive care units (ICU). Clinical and laboratory parameters collected in the first 3 days of ICU stay for 782 patients with cirrhosis and/or portal hypertension were analysed and compared with those of 273 patients with very severe cardiovascular disease (CVD). The CVD patients had more co-morbidities and higher APACHE II scores. The overall incidence of IFD was similar in the two groups, but the incidence of IFD in ICU was higher in liver patients (1% versus 0.4%; p 0.025) as was fungal colonization (23.8% versus 13.9%; p 0.001). The ICU and in-hospital mortality, and length of stay were similar in the two groups. A higher proportion of liver patients received antifungal therapy (19.2% versus 7%; p <0.0005). There was no difference in mortality between colonized patients who received antifungal therapy and colonized patients who did not. The incidence of IFD in patients with cirrhosis in ICU is higher compared with another high-risk group, although it is still very low. This risk might be higher in patients with advanced liver disease admitted with acute-on-chronic liver failure, and this should be investigated further. Our data do not support prophylactic use of antifungal therapy in cirrhosis.

Peripheral vascular tone in patients with cirrhosis: role of the renin-angiotensin and sympathetic nervous systems.

OBJECTIVE: The aims of the study were to establish the roles of angiotensin II and of the cardiopulmonary baroreceptor reflex in the regulation of peripheral vascular tone in patients with cirrhosis. METHODS: Forearm blood flow responses to subsystemic, locally active intrabrachial infusions were measured in patients with Child's Grade C cirrhosis and matched controls using bilateral venous occlusion plethysmography. Responses were determined to the angiotensin II type I receptor antagonist, losartan, noradrenaline, angiotensin II and the nitric oxide synthase inhibitor, L-NG-monomethyl arginine. RESULTS: Losartan at 30 and 90 micrograms/min caused no significant change in blood flow in controls, but caused 23 +/- 6% and 27 +/- 5% increases in patients respectively (p < 0.001). Lower body negative pressure caused a mean bilateral reduction in forearm blood flow of 20 +/- 4% in controls (p < 0.001) but only tended to reduce flow (9 +/- 5%; p = 0.06) in patients (p < 0.001; controls vs. patients). Noradrenaline, angiotensin II and L-NG-monomethyl arginine caused significant vasoconstriction (p < 0.001) in both patients and controls although angiotensin II caused significantly less vasoconstriction in patients (p = 0.01). CONCLUSIONS: We conclude that angiotensin II makes an important contribution to basal peripheral vascular tone in patients with cirrhosis in the face of reduced vascular responses to its local administration. In addition, the vasoconstrictor response to cardiopulmonary baroreceptor unloading is attenuated despite normal vascular responses to noradrenaline. These responses are consistent with chronic activation of the renin-angiotensin and sympathetic nervous systems in patients with advanced cirrhosis.

Obesity is independently associated with infection in hospitalised patients with end-stage liver disease.

BACKGROUND: Infection is the most common cause of mortality in end-stage liver disease (ESLD). The impact of obesity on infection risk in ESLD is not established. AIM: To characterise the impact of obesity on infection risk in ESLD. METHODS: We evaluated the association between infection and obesity in patients with ESLD. Patients grouped as non-obese, obesity class I-II and obesity class III were studied using the Nationwide Inpatient Sample. Validated diagnostic code based algorithms were utilised to determine weight category and infections, including bacteraemia, skin/soft tissue infection, urinary tract infection (UTI), pneumonia/respiratory infection, Clostridium difficile infection (CDI) and spontaneous bacterial peritonitis (SBP). Risk factors for infection and mortality were assessed using multivariable logistic regression analysis. RESULTS: Of 115 465 patients identified, 100 957 (87.5%) were non-obese and 14 508 (12.5%) were obese, with 9489 (8.2%) as obesity class I-II and 5019 (4.3%) as obesity class III. 37 117 patients (32.1%) had an infection diagnosis. Infection was most prevalent among obesity class III (44.0%), followed by obesity class I-II (38.9%) and then non-obese (31.9%). In multivariable modelling, class III obesity (OR = 1.41; 95% CI 1.32-1.51; P < 0.001), and class I-II obesity (OR = 1.08; 95% CI 1.01-1.15; P = 0.026) were associated with infection. Compared to non-obese patients, obese individuals had greater prevalence of bacteraemia, UTI, and skin/soft tissue infection as compared to non-obese patients. CONCLUSIONS: Obesity is newly identified to be independently associated with infection in end-stage liver disease. The distribution of infection sites varies based on weight category.

Influence of cyclic guanosine monophosphate changes on hemodynamics after reperfusion in liver transplantation.

Orthotopic liver transplantation (OLT) is often associated with hemodynamic instability upon reperfusion, recognized as postreperfusion syndrome. Changes in vascular tone due to humoral factors released upon reperfusion of the graft have been suggested as a possible mechanism. In this study, we looked at the perioperative changes in cyclic guanosine monophosphate (cGMP), a mediator of vascular smooth muscle relaxation, and investigated its relationship with hemodynamic parameters. cGMP was measured in the plasma of 14 patients undergoing OLT by radioimmunoassay serially at the preanhepatic and anhepatic phases, and after reperfusion at 30, 60, and 120 min. Hemodynamic data recorded were systemic and pulmonary arterial pressures, cardiac output, and pulmonary and systemic vascular resistance. cGMP decreased markedly after reperfusion from a baseline level of 5.33+/-0.7 ng/ml to 1.63+/-0.5 ng/ml (P<0.01). Pulmonary arterial pressure increased from 17+/-1.21 mmHg to 23.5+/-1.9 mmHg (P<0.05), and pulmonary vascular resistance increased from 62.8 +/-12.9 dynes/sec/cm5 to 135+/-42.7 dynes/sec/cm5 (P<0.01). Changes in cardiac output and systemic vascular resistance were not significant. The changes in cGMP correlated with pulmonary arterial pressure (r=0.74, P=0.005) and pulmonary vascular resistance (r=0.7, P=0.01). These data confirm the occurrence of hemodynamic changes during OLT, and provide evidence to suggest that the reduction in cGMP after reperfusion may mediate the vascular changes.

Neutrophil elastase: a determinant of endothelial damage and reperfusion injury after liver transplantation?

Reperfusion injury has been implicated in the development of primary graft dysfunction (PGD) after liver transplantation. Neutrophil migration and activation may be involved in the pathogenesis of this injury. We studied neutrophil activation and its role in the etiology of PGD by measuring neutrophil elastase by radioimmunoassay, in serial blood samples of 19 patients before, during, and for 24 hr after transplantation. In a subgroup of patients, we also measured soluble thrombomodulin at the same time points as a marker of endothelial damage. The pretransplant elastase level was significantly raised (40.13+/-4.84 ng/ml, mean+/-SEM) compared with levels of healthy controls (18.7+/-5.6 ng/ml, P<0.05). A marked increase in elastase activity followed reperfusion, with a peak at 2 hr (370+/-50.5 ng/ml, P<0.01). Thereafter, there was a decline, but elastase remained elevated at 24 hr (186+/-60.94 ng/ml). The mean increase in neutrophil elastase after reperfusion correlated significantly with markers of graft function (P<0.05) and with the mean rise in soluble thrombomodulin (P=0.042), which increased from a pretransplant level of 81.2+/-11.32 to 186+/-50.4 ng/ml, 6 hr after reperfusion (P<0.05). The results of this study indicate that marked neutrophil activation and endothelial cell damage occurs after graft reperfusion during orthotopic liver transplantation, and the degree of activation correlates with markers of graft function, which may suggest a role in the etiology of PGD.

A pilot study of indocyanine green clearance as an early predictor of graft function.

Primary graft dysfunction occurs in up to 10% of liver transplant recipients and is the major reason for early mortality and retransplantation. The conventionally used markers of early graft function--i.e., correction of acidosis, glucose requirement, consumption of potassium, serum alanine transaminase (ALT), prothrombin time (PT), bile flow, resolution of encephalopathy and haemodynamic instability can be very misleading as they are dependent on numerous other factors. The aim of this study was to assess the use of indocyanine green clearance (ICG) as a measure of graft function. Peripheral ICG clearance was measured 18-24 hr after liver transplantation in twenty-three consecutive patients (24 transplants). Doppler ultrasonography confirmed normal hepatic arterial blood flow. Correlations between ICG clearance and other markers of graft function and outcome were sought. The mean ICG clearance was 406 mls/min (SD 137.5). A threshold value of 200 ml/min reliably predicted outcome. Significant correlations were found between ICG clearance and times to normalization of PT (P < 0.02) and to the correction of acidosis (P < 0.05). No correlation was found with ALT, PT, bile flow, glucose requirement, or consumption of potassium. ICG clearance measured on the day after liver transplantation accurately reflects graft function and may be used to predict graft survival and final outcome.

Review article: quantitative tests of liver function.

The search continues for a single reliable test of liver function that provides accurate prognostic information in chronic liver disease, in acute liver failure, and about graft function following orthotopic liver transplantation. Although transaminases, the commonly used markers of hepatocellular injury, have a high sensitivity in screening for liver disease, they do not provide any information about prognosis. Rational assessment of liver function using bilirubin, serum albumin and prothrombin-time is limited by the relative lack of sensitivity of these measurements and their inability to identify the functional reserve of the liver. Dynamic liver function tests are an improvement on the static tests but are generally cumbersome. The ideal liver function test would be cheap, easy to perform and analyse, safe, have a simple pharmacokinetic profile with minimal drug interactions, have a high predictive value and provide quick results. Numerous quantitative liver function tests have been developed and have shown promise in some studies. The aim of this review is to assess the place of these tests in the practical management of liver disease.

Review article: renal circulatory changes in cirrhosis--pathogenesis and therapeutic prospects.

Renal dysfunction in cirrhosis describes a spectrum of abnormalities which lead to the clinical manifestations of ascites, peripheral oedema and hepato-renal failure. This article reviews the processes underlying this dysfunction with particular regard to the disturbance in the renal circulation. Renal haemodynamic changes occur early in cirrhosis prior to the development of ascites. However, as the liver disease progresses these changes become more profound and lead ultimately to severe cortical hypoperfusion. Renal blood flow and glomerular filtration rate do not appear to correlate well with the presence of ascites, and a separate defect in tubular sodium handling is likely to be present. The development of portal hypertension is a possible trigger of increased renal vascular resistance, whereas a deterioration in liver function may relate to the impaired tubular handling of sodium. The peripheral vasodilatation hypothesis seeks to relate these renal changes to the activation of vasopressor systems after the development of arteriolar vasodilatation. Correlations between systemic vascular resistance and renal blood flow have been difficult to establish. A variety of substances may mediate the renal circulatory changes. The likelihood is that the increase in systemic vasoconstrictors is compensatory, and that it is the locally active vasoactive substances, particularly those derived from the endothelium, which play a major role in the development of renal vasoconstriction. The management of ascites is fraught with complications, and the treatment of hepato-renal syndrome inadequate. Liver transplantation is currently the only therapy which gives any hope of long-term response and survival. Methods of improving the renal circulation by mechanically lowering portal pressure or by antagonizing locally active renal vasoconstrictors may be beneficial.

Review article: pathogenesis and treatment of chronic hepatic encephalopathy.

The various treatment strategies for hepatic encephalopathy are compared in the light of the available body of scientific work on the pathogenesis of the syndrome. Data on animal models of hepatic encephalopathy and in vitro studies on brain slices are discussed. Difficulties in extrapolating the results obtained to the human situation are highlighted, while results of human positron emission tomography and magnetic resonance spectroscopy studies are outlined on the background of the potential weaknesses of these non-invasive techniques.

Differing actions of the acute administration of propranolol and isosorbide-5-mononitrate on the portal circulation.

BACKGROUND: The aim of this study was to clarify the actions of propranolol and isosorbide-5-mononitrate upon the portal circulation. METHODS: Portal haemodynamics were assessed in 16 patients with transjugular intrahepatic portosystemic stent shunts. A reverse thermodilution catheter was positioned in the portal vein, and portal vein pressure and portal vein flow were measured directly. The effects of propranolol 80 mg and isosorbide-5-mononitrate 20 mg over 1 h were determined independently. RESULTS: This demonstrated that propranolol reduced both portal pressure gradient (7.7 +/- 2.3 to 5.5 +/- 2.1 mmHg, P < 0.01) and portal vein flow (925 +/- 123 to 597 +/- 99 mL/min, P = 0.01) significantly, implying a reduction in splanchnic inflow as its main effect. In contrast, isosorbide-5-mononitrate tended to increase portal vein flow (814 +/- 186 to 911 +/- 211 mL/min; P = 0.06) whilst reducing portal pressure significantly (108 +/- 12 to 92 +/- 10 mmHg P = 0.014). This suggests a fall in intrahepatic resistance and provides no evidence for baroreceptor-mediated reflex splanchnic vasoconstriction. CONCLUSIONS: These drugs act upon different variables contributing to portal hypertension and so they may have a powerful synergistic effect in combination. Direct measurement of portal vein flow is a valuable method for assessing the pharmacological modulation of portal venous inflow.

Review article: the molecular adsorbents recirculating system (MARS) in liver failure.

In recent years different artificial liver support systems are being developed for use in patients with acute decompensation of chronic liver disease or acute liver failure. The molecular adsorbents recirculating system (MARS), a device in which patient's blood is dialysed across an albumin-impregnated membrane against a recirculated albumin-containing solution, seems to be effective in removing albumin-bound toxins, such as fatty acids, bile acids and bilirubin. Although the clinical experience with MARS is scarce, some pilot studies have reported its effectiveness at improving liver function and hepatic encephalopathy in patients with acute decompensation of chronic liver disease, and renal function in patients with hepatorenal syndrome type I. Data regarding MARS experience in acute liver failure and in primary graft dysfunction are encouraging but limited. Its real usefulness in these settings is, at present, under evaluation in randomized controlled clinical trials.

A comparison between gastric and oesophageal variceal haemorrhage treated with transjugular intrahepatic portosystemic stent shunt (TIPSS).

BACKGROUND: Transjugular intrahepatic portosystemic stent-shunts (TIPSS) are becoming widely used in the management of oesophageal variceal haemorrhage (OVH). Their place in the treatment of gastric variceal haemorrhage (GVH), a condition with a traditionally poor prognosis, remains unclear. The aims of our study were to compare portal haemodynamics and patient outcome in patients undergoing TIPSS for either GVH or OVH. PATIENTS AND METHODS: 106 consecutive patients undergoing TIPSS at our institution for either GVH (32 patients) or OVH (74 patients) were studied. The groups were similar with regard to patient age, aetiology and severity of liver disease and number of procedures carried out as an emergency (34.4% vs. 36.5%). Episodes of shunt insufficiency, rebleeding, encephalopathy and other clinical sequela were recorded. Mean follow-up was similar in both patient groups (14.2 vs. 12.1 months). RESULTS: Baseline portocaval pressure gradient was lower in patients with GVH compared with those with OVH (13.0+/-0.9 mmHg vs. 19.0+/-0.6 mmHg) (P < 0.001). Rates of variceal rebleeding, encephalopathy and shunt insufficiency during follow-up were similar in both groups and there was no difference in survival. CONCLUSION: Patients with GVH had markedly lower portocaval pressure gradients than those with OVH, but shunt and clinical complications and survival were similar during follow-up. TIPSS appears to be an effective treatment for GVH and should be compared with endoscopic or surgical techniques in controlled trials.

Transjugular intrahepatic portosystemic stent-shunt (TIPSS): long-term follow-up.

We assessed the long-term efficacy of transjugular intrahepatic portasystemic stent-shunt (TIPSS) in 64 patients. Insertion was successful in 56 patients (87.5%). The reasons for its use were: variceal bleeding (49); ascites (6); portal hypertensive gastropathy (6); hypersplenism (2); and embolization of a spontaneous shunt (1). Fourteen patients were Childs A, 20 Childs B and 28 Childs C cirrhotics. Two patients were non-cirrhotic; one with amyloidosis and one with non-cirrhotic portal fibrosis. Patients were followed clinically and radiologically (Doppler ultrasonography and routine portography at 6 months). During 33 patient-years of follow-up, 22 died, 12 during index admission (two were procedure-related) and nine were transplanted. Twenty-five patients are alive, with a mean survival of 7.1 (SD 7) months. Variceal rebleeding occurred in 10 patients (22.7%), one of whom died, and was always associated with shunt insufficiency (shunt thrombosis 2, hepatic vein stenosis (HVS) 1, intimal hyperplasia (IH) 4, dislocated stent 1, inadequate stent 2). Clinical encephalopathy was induced in seven patients (17.1%) following TIPSS. All responded to medical therapy, but two required reduction in shunt size. Ascites improved after TIPSS in 36 patients (87.8%), but reaccumulated in seven (17.5%), associated with shunt dysfunction in five (SBP 2, IH 3, HVS 2). Fatal sepsis occurred in two patients, and 14 other episodes of infection required antibiotics. TIPSS is a useful treatment for variceal bleeding, resistant ascites and portal hypertensive gastropathy. Shunt dysfunction and sepsis occur frequently, and regular surveillance is necessary.