Liver-targeted nanoparticles delivering nitric oxide reduce portal hypertension in cirrhotic rats

Nitric oxide (NO) is a small vasodilator playing a key role in the pathogenesis of portal hypertension. Here, we assessed the potential therapeutic effect of a NO donor targeted to the liver by poly(beta-amino ester) nanoparticles (pBAE NPs) in experimental cirrhosis. Retinol-functionalized NO donor pBAE NPs (Ret pBAE NPs) were synthetized with the aim of actively targeting the liver. Administration of Ret pBAE NPs resulted in uptake and transfection by the liver and spleen. NPs were not found in other organs or the systemic circulation. Treatment with NO donor Ret pBAE NPs (30 mg/ kg body weight) significantly decreased aspartate aminotransferase, lactate dehydrogenase and portal pressure (9.75 ± 0.64 mmHg) compared to control NPs (13.4 ± 0.53 mmHg) in cirrhotic rats. There were no effects on mean arterial pressure and cardiac output. Liver-targeted NO donor NPs reduced collagen fibers and steatosis, activation of hepatic stellate cells and mRNA expression of profibrogenic and proinflammatory genes. Finally, Ret pBAE NPs displayed efficient transfection in human liver slices. Overall, liver-specific NO donor NPs effectively target the liver and mitigated inflammation and portal hypertension in cirrhotic rats. The use of Ret pBAE may prove to be an effective therapeutic strategy to treat advanced liver disease.

Resveratrol protects against Schistosoma mansoni-induced liver fibrosis by targeting the Sirt-1/NF-κB axis

Hepatic schistosomiasis is a prevalent form of chronic liver disease that drastically affects human health. Nevertheless, an antifibrotic drug that could suppress the development of hepatic fibrosis does not exist yet. The current study aimed to evaluate the effect of resveratrol, a natural polyphenol with multiple biological activities, on Schistosoma mansoni (S. mansoni)-induced hepatic fibrosis and delineate the underlying molecular mechanism. Swiss male albino mice were randomly assigned into infected and non-infected groups. Hepatic schistosomiasis infection was induced via exposure to S. mansoni cercariae. 6 weeks later, resveratrol was administrated either as 20 mg/kg/day or 100 mg/kg/day for 4 weeks to two infected groups. Another group received vehicle and served as infected control group. At the end of the study, portal hemodynamic, biochemical, and histopathological evaluation of liver tissues were conducted. Remarkably, resveratrol significantly reduced portal pressure, portal and mesenteric flow in a dose-dependent manner. It improved several key features of hepatic injury as evidenced biochemically by a significant reduction of bilirubin and liver enzymes, and histologically by amelioration of the granulomatous and inflammatory reactions. In line, resveratrol reduced the expression of pro-inflammatory markers; TNF-α, IL-1β and MCP-1 mRNA, together with fibrotic markers; collagen-1, TGF-β1 and α-SMA. Moreover, resveratrol restored SIRT1/NF-κB balance in hepatic tissues which is the main switch-off control for all the fibrotic and inflammatory mechanisms. Taken together, it can be inferred that resveratrol possesses a possible anti-fibrotic effect that can halt the progression of hepatic schistosomiasis via targeting SIRT1/ NF-κB signaling.

Candesartan cilexetil ameliorates NOSTRIN-NO dependent portal hypertension in cirrhosis and ACLF

In decompensated cirrhosis, the severity of portal hypertension (PHT) is associated with increased hepatic endothelial nitric oxide synthase (eNOS) trafficking inducer (Nostrin), but the mechanism remains unclear. AIM: To investigate: (1) Whether in cirrhosis-PHT models, ± superimposed inflammation to mimic acute-on-chronic liver failure (ACLF) modulates hepatic nitric oxide synthase trafficking inducer (NOSTRIN) expression, nitric oxide (NO) synthesis, and/or endothelial dysfunction (ED); and (2) Whether the "angiotensin II type 1 receptor blocker" candesartan cilexetil (CC) affects this pathway. CD-1 mice received intraperitoneal carbon tetrachloride injections (CCl4 15% v/v in corn oil, 0.5 mL/kg) twice weekly for 12 wk to induce cirrhosis. After 12 wk, mice were randomized to receive 2-wk oral administration of CC (8 mg/kg) ± LPS. At sacrifice, plasma (biochemical indicators, cytokines, and angiotensin II) and liver tissues (histopathology, Sirius-red stains, and molecular studies) were analysed. Moreover, Nostrin gene knockdown was tested in human umbilical vein endothelial cells (HUVECs). When compared to naïve animals, CCl4-treated animals showed markedly elevated hepatic Nostrin expression (P < 0.0001), while hepatic peNOS expression (measure of eNOS activity) was significantly reduced (P < 0.05). LPS challenge further increased Nostrin and reduced peNOS expression (P < 0.05 for both) in cirrhotic animals. Portal pressure and subsequent hepatic vascular resistance were also increased in all cirrhotic animals following LPS challenge. In CCl4 ± LPS-treated animals, CC treatment significantly reduced Nostrin (P < 0.05) and increased hepatic cGMP (P < 0.01). NOSIP, caveolin-1, NFκB, and iNOS protein expression were significantly increased in CCl4-treated animals (P < 0.05 for all). CC treatment non-significantly lowered NOSIP and caveolin-1 expression while iNOS and NFκB expression was significantly reduced in CCl4 + LPS-treated animals (P < 0.05 for both). Furthermore, Nostrin knockdown significantly improved peNOS expression and associated NO synthesis and reduced inflammation in HUVECs. This study is the first to indicate a potential mechanistic role for the Nostrin-eNOS-NO pathway in cirrhosis and ACLF development. Moreover, this pathway provides a potential therapeutic target given the ameliorative response to Candesartan treatment.

The influence of static portal pressure on liver biophysical properties

The liver is a highly vascularized organ where fluid properties, including vascular pressure, vessel integrity and fluid viscosity, play a critical role in gross mechanical properties. To study the effects of portal pressure, liver confinement, fluid viscosity, and tissue crosslinking on liver stiffness, water diffusion, and vessel size, we applied multiparametric magnetic resonance imaging (mpMRI), including multifrequency magnetic resonance elastography (MRE) and apparent diffusion coefficient (ADC) measurements, to ex vivo livers from healthy male rats (13.6±1.6 weeks) at room temperature. Four scenarios including altered liver confinement, tissue crosslinking, and vascular fluid viscosity were investigated with mpMRI at different portal pressure levels (0-17.5 cmH2O). Our experiments demonstrated that, with increasing portal pressure, rat livers showed higher water content, water diffusivity, and increased vessel sizes quantified by the vessel tissue volume fraction (VTVF). These effects were most pronounced in native, unconfined livers (VTVF: 300±120%, p<0.05, ADC: 88±29%, p<0.01), while still significant under confinement (confined: VTVF: 53±32%, p<0.01, ADC: 28±19%, p<0.05; confined-fixed: VTVF: 52±20%, p<0.001, ADC: 11±2%, p<0.01; confined-viscous: VTVF: 210±110%, p<0.01, ADC: 26±9%, p<0.001). Softening with elevated portal pressure (-12±5, p<0.05) occurred regardless of confinement and fixation. However, the liver stiffened when exposed to a more viscous inflow fluid (11±4%, p<0.001). Taken together, our results elucidate the complex relationship between macroscopic-biophysical parameters of liver tissue measured by mpMRI and vascular-fluid properties. Influenced by portal pressure, vascular permeability, and matrix crosslinking, liver stiffness is sensitive to intrinsic poroelastic properties, which, alongside vascular architecture and water diffusivity, may aid in the differential diagnosis of liver disease. STATEMENT OF SIGNIFICANCE: Using highly controllable ex vivo rat liver phantoms, hepatic biophysical properties such as tissue-vascular structure, stiffness, and water diffusivity were investigated using multiparametric MRI including multifrequency magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI). Through elaborate tuning of the experimental conditions such as the static portal pressure, flow viscosity, amount and distribution of fluid content in the liver, we identified the contributions of the fluid component to the overall imaging-based biophysical properties of the liver. Our finding demonstrated the sensitivity of liver stiffness to the hepatic poroelastic properties, which may aid in the differential diagnosis of liver diseases.

Endoscopic ultrasound-guided portal pressure gradient measurement in managing portal hypertension

Portal hypertension (PH) is still a challenging clinical condition due to its silent manifestations in the early stage and needs to be measured accurately for early detection. Hepatic vein pressure gradient measurement has been considered as the gold standard measurement for PH; however, it needs special skill, experience, and high expertise. Recently, there has been an innovative development in using endoscopic ultrasound (EUS) for the diagnosis and management of liver diseases, including portal pressure measurement, which is commonly known as EUS-guided portal pressure gradient (EUS-PPG) measurement. EUS-PPG measurement can be performed concomitantly with EUS evaluation for deep esophageal varices, EUS-guided liver biopsy, and EUS-guided cyanoacrylate injection. However, there are still major issues, such as different etiologies of liver disease, procedural training, expertise, availability, and cost-effectiveness in several situations with regard to the standard management.

Left gastric vein embolization during TIPS placement for acute variceal bleeding has no effect on bleeding recurrence: Results of a multicenter study

PURPOSE

The purpose of this study was to evaluate whether concomitant left gastric vein embolization (LGVE) during transjugular intrahepatic portosystemic shunt (TIPS) for acute variceal hemorrhage could reduce the risk of bleeding recurrence.

MATERIAL AND METHOD

A national multicenter observational study was conducted in 14 centers between January 2019 and December 2020. All cirrhotic patients who underwent TIPS placement for acute variceal bleeding were included. During TIPS procedure, size of left gastric vein (LGV), performance of LGVE, material used for LGVE and portosystemic pressure gradient (PPG) before and after TIPS placement were collected. A propensity score for the occurrence of LGVE was calculated to assess effect of LGVE on rebleeding recurrence at six weeks and one year.

RESULTS

A total of 356 patients were included (mean age 57.3 ± 10.8 [standard deviation] years; 283/356 [79%] men). Median follow-up was 11.2 months [interquartile range: 1.2, 13.3]. The main indication for TIPS was pre-emptive TIPS (162/356; 46%), rebleeding despite secondary prophylaxis (105/356; 29%), and salvage TIPS (89/356; 25%). Overall, 128/356 (36%) patients underwent LGVE during TIPS procedure. At six weeks and one year, rebleeding-free survival did not differ significantly between patients who underwent LGVE and those who did not (6/128 [5%] vs. 15/228 [7%] at six weeks, and 11/128 [5%] vs. 22/228 [7%] at one year, P = 0.622 and P = 0.889 respectively). A total of 55 pairs of patients were retained after propensity score matching. In patients without LGVE, the rebleeding rate was not different from those with LGVE (3/55 [5%] vs. 4/55 [7%], P > 0.99, and 5/55 [9%] vs. 6/55[11%], P > 0.99, at six weeks and one year respectively). Multivariable analysis identified PPG after TIPS placement as the only predictor of bleeding recurrence (hazard ratio = 1.09; 95% confidence interval: 1.02-1.18; P = 0.012).

CONCLUSION

In this multicenter national real-life study, we did not observe any benefit of concomitant LGVE during TIPS placement for acute variceal bleeding on bleeding recurrence rate.

Computational hemodynamic analysis for optimal stent position in the transjugular intrahepatic portosystemic shunt procedure

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective treatment for portal hypertension (PH). The current study aimed to investigate the effect of stent position on post-TIPS hemodynamic performance using computational fluid dynamics. Patient-specific pre- and post-TIPS models were reconstructed from CT images of two patients, then virtual TIPS models were created by shifting the portal vein (PV) entry site of the stent. Although there were marginal differences the effects of left-sided and right-sided TIPS on post-TIPS portal pressure and shunting flow, right-sided TIPS resulted in a greater proportion of superior mesenteric vein (SMV) flow diverting to stents compared to that for left-sided TIPS. The results also demonstrated that the nearer the entry site of stent to the portal venous bifurcation, the greater and more stable the shunting blood flow. These results suggest that the entry site of the stent should be as close to the portal vein bifurcation as possible during TIPS. TIPS on the right branch of the portal vein may be more likely to result in post-TIPS hepatic encephalopathy than that on the left branch.

Second-harmonic generation (SHG) microscopy and hepatic venous pressure gradient-based validation of a novel histological staging system for alcoholic hepatitis

Alcoholic hepatitis (AH) lacks specific histological staging. A novel fibrosis staging that encompasses perisinusoidal fibrosis and cirrhosis sub-stages, substantiated by Hepatic venous pressure gradient (HVPG) and automated fibrosis quantification, is imperative. To correlate novel histological staging system of AH with second-harmonic generation microscopy (SHG)-based q-fibrosis, HVPG, and activated hepatic stellate cells (HSCs). Liver biopsies of AH (n = 175) were staged semi-quantitatively as F0, F1, F2, F3A and F3B and Laennec substages of cirrhosis 4A, 4B and 4C. Stages were correlated with SHG q-fibrosis parameters, HVPG and HSCs. Mean age 41.2 ± 9.4 years, 96.6% males, bilirubin 20.58 ± 8.0 mg/dl and Maddrey's discriminant function 78.9 ± 36.7 displayed advanced fibrosis in 98.6%. With increasing histological stages, an increase in q-fibrosis indices and mean HVPG (p < 0.0001) were recorded; stage 4C showed the most significant difference from other stages (p < 0.000). Stages 3A and 3B were comparable with the stages 4A and 4B, respectively, for q-fibrosis (p = 1) and HVPG (p = 1). HSCs (> 30%) were significantly higher in stage 3 (75%) compared with 4 (49%) and 2 (59%), p = 0.018. Overall agreement for histological staging was excellent for all stages (0.82). SHG quantified fibrosis and HVPG corroborates the novel histological staging of AH. Expansive PCF matches with collagen content and clinical severity to early sub-stages of cirrhosis. This highlights the need for an accurate quantification and inclusion of PCF as a separate stage. SHG-based quantification can be a useful adjunct to histological fibrosis staging systems.

Predicting the risk of post-hepatectomy portal hypertension using a digital twin: A clinical proof of concept

BACKGROUND & AIMS

Despite improvements in medical and surgical techniques, post-hepatectomy liver failure (PHLF) remains the leading cause of postoperative death. High postoperative portal vein pressure (P_PV) and portocaval gradient (PCG), which cannot be predicted by current tools, are the most important determinants of PHLF. Therefore, we aimed to evaluate a digital twin to predict the risk of postoperative portal hypertension (PHT).

METHODS

We prospectively included 47 patients undergoing major hepatectomy. A mathematical (0D) model of the entire blood circulation was assessed and automatically calibrated from patient characteristics. Hepatic flows were obtained from preoperative flow MRI (n = 9), intraoperative flowmetry (n = 16), or estimated from cardiac output (n = 47). Resection was then simulated in these 3 groups and the computed P_PV and PCG were compared to intraoperative data.

RESULTS

Simulated post-hepatectomy pressures did not differ between the 3 groups, comparing well with collected data (no significant differences). In the entire cohort, the correlation between measured and simulated P_PV values was good (r = 0.66, no adjustment to intraoperative events) or excellent (r = 0.75) after adjustment, as well as for PCG (respectively r = 0.59 and r = 0.80). The difference between simulated and measured post-hepatectomy PCG was ≤3 mmHg in 96% of cases. Four patients suffered from lethal PHLF for whom the model satisfactorily predicted their postoperative pressures.

CONCLUSIONS

We demonstrated that a 0D model could correctly anticipate postoperative PHT, even using estimated hepatic flow rates as input data. If this major conceptual step is confirmed, this algorithm could change our practice toward more tailor-made procedures, while ensuring satisfactory outcomes.

LAY SUMMARY

Post-hepatectomy portal hypertension is a major cause of liver failure and death, but no tool is available to accurately anticipate this potentially lethal complication for a given patient. Herein, we propose using a mathematical model to predict the portocaval gradient at the end of liver resection. We tested this model on a cohort of 47 patients undergoing major hepatectomy and demonstrated that it could modify current surgical decision-making algorithms.

Regression of portal hypertension: underlying mechanisms and therapeutic strategies

Portal hypertension is the main non-neoplastic complication of chronic liver disease, being the cause of important life-threatening events including the development of ascites or variceal bleeding. The primary factor in the development of portal hypertension is a pathological increase in the intrahepatic vascular resistance, due to liver microcirculatory dysfunction, which is subsequently aggravated by extra-hepatic vascular disturbances including elevation of portal blood inflow. Evidence from pre-clinical models of cirrhosis has demonstrated that portal hypertension and chronic liver disease can be reversible if the injurious etiological agent is removed and can be further promoted using pharmacological therapy. These important observations have been partially demonstrated in clinical studies. This paper aims at providing an updated review of the currently available data regarding spontaneous and drug-promoted regression of portal hypertension, paying special attention to the clinical evidence. It also considers pathophysiological caveats that highlight the need for caution in establishing a new dogma that human chronic liver disease and portal hypertension is reversible.

Noninvasive diagnosis of portal hypertension using gadoxetate DCE-MRI of the liver and spleen

OBJECTIVES

To assess the performance of gadoxetate dynamic contrast-enhanced (DCE) MRI of the liver and spleen for noninvasive diagnosis of portal hypertension (PH).

METHODS

Thirty-five patients (M/F 22/13, mean age 55 years) with chronic liver disease who underwent hepatic venous pressure gradient (HVPG) measurements were prospectively enrolled in this IRB-approved study. All patients underwent multiparametric MRI including gadoxetate DCE-MRI acquisition. Model-based and model-free DCE-MRI analyses were performed. The correlation between DCE-MRI parameters and HVPG was assessed. ROC analysis was employed to determine the diagnostic performance of DCE-MRI parameters alone and in combination for prediction of PH and clinically significant (CS)PH (HVPG > 5 and ≥ 10 mmHg, respectively).

RESULTS

Mean HVPG was 7.0 ± 5.0 mmHg (range 0-18 mmHg). Twenty-one (60%) patients had PH, of whom 9 had CSPH. Modeled liver uptake fraction f_i and uptake rate k_i and model-free parameters liver upslope and uptake were all significantly negatively correlated with HVPG (r range - 0.490 to - 0.398, p value range 0.003-0.018), while spleen interstitial fraction v_e was significantly positively correlated with HVPG (r = 0.336, p = 0.048). For PH diagnosis, liver k_i showed the best diagnostic performance with an AUC, sensitivity, and specificity of 0.74 (confidence interval (CI) 0.57-0.91), 71.4%, and 78.6%. The combination of liver k_i and spleen v_e was selected as the best classifier for diagnosis of CSPH with an AUC, sensitivity, and specificity of 0.87 (CI 0.75-0.99), 100%, and 73.1%.

CONCLUSIONS

Our results demonstrate the potential utility of hepatocyte uptake parameters and spleen interstitial fraction obtained with gadoxetate DCE-MRI for the diagnosis of PH and CSPH.

KEY POINTS

• Liver uptake and spleen interstitial fraction estimates from gadoxetate DCE-MRI are significantly correlated with portal pressure measurements. • Liver uptake rate shows good diagnostic performance for the diagnosis of portal hypertension. • The combination of liver uptake rate with spleen interstitial fraction exhibits excellent diagnostic performance for the diagnosis of clinically significant portal hypertension.

Change in Portal Pressure and Clinical Outcome in Cirrhotic Patients with Gastric Varices after Plug-Assisted Retrograde Transvenous Obliteration

Background/Aims

Plug-assisted retrograde transvenous obliteration (PARTO) is widely used to manage gastric varices with a portosystemic shunt. It is not clear whether portal pressure and the incidence of complications increase after PARTO. The aim of this study was to determine the changes in portal pressure and the associated changes in liver function, ascites, hepatic encephalopathy, and especially esophageal varix (EV) after PARTO.

Methods

From March 2012 to February 2018, 54 patients who underwent PARTO were analyzed retrospectively. The parameters collected included liver function and episodes of cirrhotic complications before and at 1 and 6 months after PARTO.

Results

The analysis of 54 patients showed improvement in liver function during the 6-month follow-up period (Model for End-Stage Liver Disease score: change from 11.46±4.35 to 10.33±2.96, p=0.021). Among these 54 patients, 25 patients were evaluated for their hepatic venous pressure gradient (HVPG) before and after PARTO (change from 12.52±3.83 to 14.68±5.03 mm Hg; p<0.001). Twenty-five patients with portal pressure measured before and after PARTO were evaluated for risk factors affecting liver function improvement and EV deterioration. No factor associated with portal pressure was affected by liver function improvement. Post-PARTO portal pressure was a risk factor affecting EV deterioration (HVPG-post: odds ratio, 1.341; 95% confidence interval, 1.017 to 1.767; p=0.037).

Conclusions

The artificial blockade of the portosystemic shunt evidently leads to an increase in HVPG. Liver function was improved over the 6-month follow-up period. Portal pressure after PARTO was a significant risk factor for EV deterioration. Portal pressure measurement is helpful for predicting the patient's clinical outcome.

Study of factors affecting Small for Size Syndrome Post-Adult living donor liver transplantation

AIM

Recently, increasing evidence showed that small-for-size syndrome (SFSS) is a multifactorial disease which is precipitated by various perioperative factors other than graft size. We conducted the current work to evaluate perioperative effectors, which can increase the risk of SFSS following adult living-donor liver transplantation (LDLT).

METHODS

This is a retrospective study on 110 adult cirrhotic cases (mean age of 48.4 ± 6.9 years old) who underwent adult LDLT. Most cases were males (89%). Cases were categorized into two groups based on the occurrence of SFSS. The groups were compared regarding preoperative (gender, age, comorbidities, baseline investigations), intraoperative (mean blood pressure and glucose; mean operation time; number of packed red cells, plasma, platelets, and cryoprecipitate units; time of cold and warm ischemia, and anhepatic phase; preclamping and post-reperfusion portal pressures), and postoperative factors (relevant investigations, hospital stay).

RESULTS

Postoperatively, 23 patients developed SFSS (20.9%). SFSS group had significantly lower preoperative graft recipient weight ratio (GRWR) (0.76 ± 0.1% versus 1.03 ± 0.15, respectively; p < 0.001), and elevated MELD scores (19 ± 2.1 versus 17.9 ± 4; p = 0.024). Preclamping and post-reperfusion portal pressures of ≥22.5 and 17.5 mmHg, exhibited a sensitivity of 95.7% and 91.3% and specificity of 87.4% and 88.9% respectively, for SFSS prediction.

CONCLUSION

SFSS risk is significantly linked to GRWR, MELD score, and intraoperative portal haemodynamics. Intraoperative portal haemodynamics exhibited good diagnostic accuracy for SFSS prediction and represented promising indicators for the prediction of SFSS.

Assessment of a biofluid mechanics-based model for calculating portal pressure in canines

BACKGROUND

Portal hypertension is a severe complication caused by various chronic liver diseases. The standard methods for detecting portal hypertension (hepatic venous pressure gradient and free portal pressure) are available in only a few hospitals due to their technical difficulty and invasiveness; thus, non-invasive measuring methods are needed. This study aimed to establish and assess a novel model to calculate free portal pressure based on biofluid mechanics.

RESULT

Comparison of each dog's virtual and actual free portal pressure showed that a biofluid mechanics-based model could accurately predict free portal pressure (mean difference: -0.220, 95% CI: - 0.738 to 0.298; upper limit of agreement: 2.24, 95% CI: 1.34 to 3.14; lower limit of agreement: -2.68, 95% CI: - 3.58 to - 1.78; intraclass correlation coefficient: 0.98, 95% CI: 0.96 to 0.99; concordance correlation coefficient: 0.97, 95% CI: 0.93 to 0.99) and had a high AUC (0.984, 95% CI: 0.834 to 1.000), sensitivity (92.3, 95% CI: 64.0 to 99.8), specificity (91.7, 95% CI: 61.5 to 99.8), positive likelihood ratio (11.1, 95% CI: 1.7 to 72.8), and low negative likelihood ratio (0.08, 95% CI: 0.01 to 0.6) for detecting portal hypertension.

CONCLUSIONS

Our study suggests that the biofluid mechanics-based model was able to accurately predict free portal pressure and detect portal hypertension in canines. With further research and validation, this model might be applicable for calculating human portal pressure, detecting portal hypertensive patients, and evaluating disease progression and treatment efficacy.

Accurate ultrasonography-based portal pressure assessment in patients with hepatocellular carcinoma

BACKGROUND

Portal pressure is of great significance in the treatment of hepatocellular carcinoma (HCC), but direct measurement is complicated and costly; thus, non-invasive measurement methods are urgently needed.

AIM

To investigate whether ultrasonography (US)-based portal pressure assessment could replace invasive transjugular measurement.

METHODS

A cohort of 102 patients with HCC was selected (mean age: 54 ± 13 years, male/female: 65/37). Pre-operative US parameters were assessed by two independent investigators, and multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for the portal pressure gradient (PPG). The estimated PPG predictors were compared with the transjugular PPG measurements. Validation was conducted on another cohort of 20 non-surgical patients.

RESULTS

The mean PPG was 17.32 ± 1.97 mmHg. Univariate analysis identified the association of the following four parameters with PPG: Spleen volume, portal vein diameter, portal vein velocity (PVV), and portal blood flow (PBF). Multiple linear regression analysis was performed, and the predictive formula using the PVV and PBF was as follows: PPG score = 19.336 - 0.312 × PVV (cm/s) + 0.001 × PBF (mL/min). The PPG score was confirmed to have good accuracy with an area under the curve (AUC) of 0.75 (0.68-0.81) in training patients. The formula was also accurate in the validation patients with an AUC of 0.820 (0.53-0.83).

CONCLUSION

The formula based on ultrasonographic Doppler flow parameters shows a significant correlation with invasive PPG and, if further confirmed by prospective validation, may replace the invasive transjugular assessment.

Randomized placebo-controlled trial of emricasan for non-alcoholic steatohepatitis-related cirrhosis with severe portal hypertension

BACKGROUND & AIMS

Emricasan, an oral pan-caspase inhibitor, decreased portal pressure in experimental cirrhosis and in an open-label study in patients with cirrhosis and severe portal hypertension, defined as a hepatic venous pressure gradient (HVPG) ≥12 mmHg. We aimed to confirm these results in a placebo-controlled study in patients with non-alcoholic steatohepatitis (NASH)-related cirrhosis.

METHODS

We performed a multicenter double-blinded study, randomizing 263 patients with NASH-related cirrhosis and baseline HVPG ≥12 mmHg to twice daily oral emricasan 5 mg, 25 mg, 50 mg or placebo in a 1:1:1:1 ratio for up to 48 weeks. The primary endpoint was change in HVPG (ΔHVPG) at week 24. Secondary endpoints were changes in biomarkers (aminotransferases, caspases, cytokeratins) and development of liver-related outcomes.

RESULTS

There were no significant differences in ΔHVPG for any emricasan dose vs. placebo (-0.21, -0.45, -0.58 mmHg, respectively) adjusted for baseline HVPG, compensation status, and non-selective beta-blocker use. Compensated patients (n = 201 [76%]) tended to have a greater decrease in HVPG (emricasan all vs. placebo, p = 0.06), the decrease being greater in those with higher baseline HVPG (p = 0.018), with a significant interaction between baseline HVPG (continuous, p = 0.024; dichotomous at 16 mmHg [median], p = 0.013) and treatment. Biomarkers decreased significantly with emricasan at week 24 but returned to baseline levels by week 48. New or worsening decompensating events (∼10% over median exposure of 337 days), progression in model for end-stage liver disease and Child-Pugh scores, and treatment-emergent adverse events were similar among treatment groups.

CONCLUSIONS

Despite a reduction in biomarkers indicating target engagement, emricasan was not associated with improvement in HVPG or clinical outcomes in patients with NASH-related cirrhosis and severe portal hypertension. Compensated patients with higher baseline HVPG had evidence of a small treatment effect. Emricasan treatment appeared safe and well-tolerated.

LAY SUMMARY

Cirrhosis (scarring of the liver) is the main consequence of non-alcoholic steatohepatitis (NASH). Cirrhosis leads to high pressure in the portal vein which accounts for most of the complications of cirrhosis. Reducing portal pressure is beneficial in patients with cirrhosis. We studied the possibility that emricasan, a drug that improves inflammation and scarring in the liver, would reduce portal pressure in patients with NASH-related cirrhosis and severe portal hypertension. Our results in a large, prospective, double-blind study could not demonstrate a beneficial effect of emricasan in these patients.

CLINICAL TRIAL NUMBER

Clinical Trials.gov #NCT02960204.

Effects of terlipressin infusion during hepatobiliary surgery on systemic and splanchnic haemodynamics, renal function and blood loss: a double-blind, randomized clinical trial

Background

Terlipressin, in general, is a vasopressor which acts via V1 receptors. Its infusion elevates mean blood pressure and can reduce bleeding which has a splanchnic origin. The primary outcome was to assess the impact of intraoperative terlipressin infusion on portal venous pressure during hepatobiliary surgery; the 2ry outcomes included effects upon systemic hemodynamics, estimated blood loss, and postoperative renal functions.

Methods

This prospective randomized study involved 50 patients undergoing hepatobiliary surgery who were randomly and equally allocated into terlipressin group, or a control group. The terlipressin group received an initial bolus dose of (1 mg over 30 min) followed by a continuous infusion of 2 μg/kg/h throughout the procedure and gradually weaned over the first four postoperative hours, whereas the control group received the same volumes of normal saline. The portal venous pressure changes were measured directly through a portal vein angiocatheter.

Results

Portal pressure was significantly reduced over time in the terlipressin group only (from 17.88 ± 7.32 to 15.96 ± 6.55 mmHg, p < .001). Mean arterial blood pressure was significantly higher in the terlipressin group. Estimated blood loss was significantly higher in the control group than the terlipressin group (1065.7 ± 202 versus 842 ± 145.5 ml; p = 0.004), and the units of packed RBCs transfused were significantly higher in the control group ((0–2) versus (0–4) p = 0.003). There was no significant difference between groups as regards the incidence of acute kidney injury.

Conclusion

Intraoperative infusion of terlipressin during hepatobiliary surgery was shown to improve intraoperative portal hemodynamics with subsequent reduction in blood loss.

Trial registration

Clinical trial number and registry URL: Trial registration number: NCT02718599. Name of registry: ClinicalTrials.gov. URL of registry: https://clinicaltrials.gov/ct2/show/NCT02718599. Date of registration: March 2016. Date of enrolment of the first participant to the trial: April 2016.

Portal pressure gradient and serum albumin: A simple combined parameter associated with the appearance of ascites in decompensated cirrhosis treated with transjugular intrahepatic portosystemic shunt

Background/Aims

In recent years, greater assessment accuracy after transjugular intrahepatic portosystemic shunt (TIPS) to ascertain prognosis has become important in decompensated cirrhosis due to portal hypertension. The aim of this study was to assess the ratio of the portal pressure gradient (PPG) pre-TIPS (pre-PPG) to albumin (PPA), which influence ascites formation in cirrhotic patients in the 6-months after TIPS placement, and is a metric introduced in our study.

Methods

This was a retrospective cohort study of 58 patients with decompensated cirrhosis admitted to an academic hospital for the purpose of TIPS placement. We collected the following data: demographics, laboratory measures, and PPG during the TIPS procedure. Then we analyzed the association between the above data and ascites formation postTIPS in cirrhosis patients.

Results

Twenty-two patients with ascites and 28 without ascites were evaluated. Univariate and binary logistic regression analysis were adjusted for the following variables: to determine prognosis; Child-Pugh scores, lymphocyte count, platelet count, hemoglobin level, albumin level and pre-PPG or PPA. The outcome showed that PPA was better than pre-PPG and albumin for predicting ascites according to area under receiver operating characteristic curves and a statistical model that also showed PPA’s influence 6-months post-TIPS.

Conclusions

The combined measurement of pre-PPG and albumin, defined as PPA, may provide a better way to predict post-TIPS ascites in decompensated cirrhosis, which underlines the need for a large clinical trial in the future.

Dabigatran Reduces Liver Fibrosis in Thioacetamide-Injured Rats

BACKGROUND

Liver fibrosis can progress to cirrhosis, hepatocellular carcinoma, or liver failure. Unfortunately, the antifibrotic agents are limited. Thrombin activates hepatic stellate cells (HSCs). Therefore, we investigated the effects of a direct thrombin inhibitor, dabigatran, on liver fibrosis.

METHODS

Adult male Sprague-Dawley rats were injected intraperitoneally with thioacetamide (TAA, 200 mg/kg twice per week) for 8 or 12 weeks to induce liver fibrosis. The injured rats were assigned an oral gavage of dabigatran etexilate (30 mg/kg/day) or vehicle in the last 4 weeks of TAA administration. Rats receiving an injection of normal saline and subsequent oral gavage of dabigatran etexilate or vehicle served as controls.

RESULTS

In the 8-week TAA-injured rats, dabigatran ameliorated fibrosis, fibrin deposition, and phosphorylated ERK1/2 in liver, without altering the transcript expression of thrombin receptor protease-activated receptor-1. In vitro, dabigatran inhibited thrombin-induced HSC activation. Furthermore, dabigatran reduced intrahepatic angiogenesis and portal hypertension in TAA-injured rats. Similarly, in the 12-week TAA-injured rats, a 4-week treatment with dabigatran reduced liver fibrosis and portal hypertension.

CONCLUSIONS

By inhibiting thrombin action, dabigatran reduced liver fibrosis and intrahepatic angiogenesis. Dabigatran may be a promising therapeutic agent for treatment of liver fibrosis.

Hemodynamic characteristics of biliary cirrhosis in rats

AIM

To elucidate the hemodynamic characteristics of biliary cirrhosis in common bile duct ligated rats.

METHODS

Biliary cirrhosis was induced in rats by common bile duct ligation (CBDL). Rats were divided into a sham group and a CBDL group. At the end of 4 weeks, portal pressure (PP) and mean arterial pressure (MAP) were measured directly via catheters. Liver or spleen coefficient was the ratio of liver weight or spleen weight to body weight. Proliferation of fibrous tissue was evaluated by Masson staining.

RESULTS

At the end of 4 wk, the liver of CBDL rats was yellow in color and enlarged. The surface of some livers was scattered with numerous nodules. Masson staining indicated extensive proliferation of fibrous tissue and pseudolobule. PP of CBDL rats was increased and MAP was decreased compared with sham rats. There was a significant positive correlation between PP and MAP (R² = 0.9096). PP of rats with severe ascites was lower than that of rats with mild or no ascites.

CONCLUSION

After 4 wk of CBDL, liver cirrhosis and portal hyper-tension develop. PP is determined by the degree of ascites and MAP.

[Current status and prospects of integrated traditional Chinese and Western medicine for treatment of portal hypertension]

Portal hypertension refers to a series of clinical manifestations caused by elevated pressure of the portal vein system, which can cause portal hypertension by causing portal venous obstruction and / or increased blood flow. A typical clinical manifestation in patients with decompensated cirrhosis is portal hypertension. A severe complication of portal hypertension is esophagogastric varices bleeding, refractory ascites, and hepatic encephalopathy. The effective reduction of portal pressure can reduce the incidence of complications, improve the prognosis and reduce the mortality. At present, the commonly used clinical methods for reducing portal hypertension include drug therapy, minimally invasive interventions, surgical treatment, and liver transplantation. This article reviews the current status of integrated traditional Chinese and Western medicine for portal hypertension.

Symptomatic Heart Failure After Transjugular Intrahepatic Portosystemic Shunt Placement: Incidence, Outcomes, and Predictors

PURPOSE

To assess the incidence of symptomatic heart failure (SHF) occurring after transjugular intrahepatic portosystemic shunt (TIPS) placement, identify potential predictors of SHF, and evaluate clinical presentation and outcomes in cases of post-TIPS SHF.

MATERIALS AND METHODS

A prospectively maintained TIPS database was used to identify patients who underwent new TIPS placements at a large urban tertiary care center between 1995 and 2014. SHF was defined as otherwise unexplained new-onset dyspnea, hypoxemia, radiologic pulmonary edema, an increased need for diuretics, or need for intubation within 7 days after TIPS placement. Cases of deaths occurring within 7 days due to septic shock, continuing gastrointestinal bleed, or multi-organ failure were excluded. A control group consisting of a random sample of 40 patients from the same TIPS database was created. Uni-variable analysis was performed to assess differences between patients with and without post-TIPS SHF.

RESULTS

Of the 934 TIPS procedures performed during the study period, 883 met the inclusion criteria. Eight (0.9%) patients developed SHF, usually manifested by hypoxemia (50%) or dyspnea (25%) within 48 h. Patients with SHF had higher pre-TIPS right atrial (p = 0.03) and portal vein (p = 0.01) pressures, higher albumin (p = 0.02), and higher prothrombin time (p = 0.02).

CONCLUSION

Post-TIPS SHF is rare. Higher pre-TIPS right atrial and portal vein pressures are likely to predispose patients to this complication. Close monitoring may be warranted in these patients. In our eight patients, post-TIPS SHF did not result in poor outcomes.

Supersonic Shear Wave Imaging of the Spleen for Staging of Liver Fibrosis in Rats

The goal of the work described here was to explore the cause of spleen stiffness (SS) in hepatic fibrogenesis and evaluate the value of SS in liver fibrosis (LF) staging. LF was induced with carbon tetrachloride (CCl₄) in rats (n = 40). Supersonic shear wave imaging and contrast-enhanced ultrasound were performed to determine liver stiffness (LS), SS and splenic hemodynamics. SS, LS and free portal pressure exhibited moderate correlations with fibrosis stage (r = 0.744-0.835, p < 0.001). Time-intensity curves of contrast-enhanced ultrasound for the spleen were presented as decreasing peak intensity and slope of decrease, and increasing time to peak. Splenic sinus dilation and congestion were observed on histopathologic analysis. The area under the receiver operating characteristic curve of SS was higher than that of LS for differentiating LF stages 0-2 from stages 3-4 (Z = 2.293, p = 0.02). SS is a reliable diagnostic marker for the assessment of LF in the CCl₄ model, especially for severe fibrosis. Elevated portal pressure is the cause of increasing SS.

Hepatic Venous Pressure Gradient Measurement in Bangladeshi Cirrhotic Patients: A Correlation with Child's Status, Variceal Size, and Bleeding

Background:

Hepatic venous pressure gradient (HVPG) reflects the portal pressure in patients with cirrhotic portal hypertension. The aim of the study was to assess the relation of HVPG to variceal size, Child-Pugh status, and variceal bleeding.

Materials and methods:

A total of 96 patients with cirrhosis of liver were enrolled prospectively and each patient’s HVPG level was measured via the transfemoral route. Clinical and biochemical evaluation and upper gastrointestinal (GI) endoscopy were done in each subject. Severity of cirrhosis was assessed by Child’s status.

Results:

The mean HVPG was higher in patients with Child’s B and C (14.10 ± 7.56 and 13.64 ± 7.17 mm Hg respectively) compared with those of Child’s A (10.15 ± 5.63 mm Hg). The levels of HVPG differed significantly between Child’s classes A and B (p = 0.011) and Child’s A and C (p = 0.041). The mean HVPG was also higher in bleeders compared with nonbleeders with large varices (17.7 ± 5.5 vs 14.9 ± 4.7 mmHg respectively; p = 0.006).

Conclusion:

Hepatic venous pressure gradient seems to be important to assess the severity of liver cirrhosis.

How to cite this article: Al Mahtab M, Noor E Alam SM, Rahim MA, Alam MA, Khondaker FA, Moben AL, Mohsena M, Akbar SMF. Hepatic Venous Pressure Gradient Measurement in Bangladeshi Cirrhotic Patients: A Correlation with Child’s Status, Variceal Size, and Bleeding. Euroasian J Hepato-Gastroenterol 2017;7(2):142-145.

Renoportal Anastomosis in Left Lateral Lobe Living Donor Liver Transplantation: A Pediatric Case

In adult liver transplantation, renoportal anastomosis (RPA) has been introduced as a useful technique for patients with grade 4 portal vein thrombosis and a splenorenal shunt. Here, we report a pediatric case in which RPA allowed a left lateral lobe living donor liver transplantation (LDLT) despite portal vein thrombosis and a large splenorenal shunt. At 36 days old, the patient underwent a Kasai operation for biliary atresia. At 17 months old, she underwent LDLT because of repetitive cholangitis. Pretransplant examinations revealed a large splenorenal shunt and portal vein thrombosis. Simple end-to-end portal reconstruction and clamping of the collateral route after removing the thrombosis were unsuccessful. Thus, RPA was performed using a donor superficial femoral vein as an interpositional graft. The portal vein pressure was 20 mm Hg after arterial reperfusion. Ligation of the splenic artery reduced the portal vein pressure. Although she developed severe acute cellular rejection and chylous ascites, there were no signs of portal vein complications. She was discharged 73 days after transplantation without any signs of renal dysfunction. The patient's condition was good at her last follow-up, 22 months after transplantation. To our knowledge, this is the youngest case of RPA in pediatric left lateral lobe LDLT. Additionally, this is the first case of RPA with splenic artery ligation and using the donor's superficial femoral vein as the venous graft for RPA. Although long-term follow-up is necessary, RPA could be a salvage option in LDLT in infants if other methods are unsuccessful.

Endoscopic Ultrasound-Guided Vascular Therapy: The Present and the Future

Endoscopic ultrasound (EUS) offers access to many intra-abdominal vessels that until now have only been accessible to the surgeon and interventional radiologist. In addition to assisting with diagnostics, this unique access offers the potential for therapeutic intervention for a host of indications. To date, this has had the most clinical impact in the treatment of gastroesophageal varices, with EUS-guided coil and glue application growing in use worldwide. Although randomised controlled trial data is lacking, we discuss the growing body of literature behind EUS-guided therapy in the management of varices. EUS has also been used in specialized centres to assist in non-variceal gastrointestinal bleeding. The treatment of bleeding from Dieulafoy lesions, tumours and pancreatic pseudoaneurysms has all been described. The potential applications of EUS have also extended to the placement of portal vein stents and porto-systemic shunts in animal models. As medicine continues to move to increasingly less invasive interventions, EUS-guided therapies offer substantial promise for the safe and effective delivery of targeted treatment for a widening array of vascular disorders.

Liver regeneration after different degrees of portal vein ligation

BACKGROUND

Selective portal vein ligation (PVL) is followed by ipsilateral atrophy and contralateral hypertrophy of the liver lobes. Although the atrophy-hypertrophy complex induced by PVL is a well-documented phenomenon, the effect of different degrees of extended portal vein occlusion on liver regeneration is not known. The aim of this study was to assess the effects of different degrees of portal occlusion on portal pressure and liver regeneration.

MATERIALS AND METHODS

Male Wistar rats (n = 96; 220-250 g) were randomized into three groups and underwent 70%, 80%, or 90% portal vein ligation, respectively. The portal pressure was measured immediately and 24, 48, 72, 120, and 168 h after PVL (n = 6/group/time point). The hepatic lobes and the spleen were weighed, and liver regeneration ratio was calculated. Changes in liver histology and the mitotic activity were assessed on hematoxylin-eosin stained slides.

RESULTS

Higher degree of portal occlusion triggered a stronger regenerative response (regeneration ratio of PVL 70%168h = 2.23 ± 0.13, PVL 80%168h = 3.11 ± 0.37, PVL 90%168h = 4.68 ± 0.48) PVL led to an immediate increase in portal pressure, the value of which changed proportionally to the mass of liver tissue deprived of portal perfusion (PVL 70%acute = 17 ± 2 mm Hg, PVL 80%acute = 19 ± 1 mm Hg, PVL 90%acute = 26 ± 4 mm Hg). Findings in histology showed necro-apoptotic lesions in the atrophic liver lobes and increased mitotic cell count in the hypertrophic lobes. The mitotic cell count of PVL 90% peaked earlier and at a significantly higher value than of PVL 70% and PVL 80% (PVL 9024h%: 96.0 ± 3.5 PVL 70%48h: 64.0 ± 2.1, PVL 80%48h: 56.3 ± 4.0). The mitotic index after 24 h showed a strong correlation with the acute portal hypertension.

CONCLUSIONS

A higher degree of portal vein occlusion leads to a greater regenerative response, presumably triggered by the proportional increase in portal pressure, which supports the role of the so-called "blood-flow" theory of PVL-triggered liver regeneration.

Cerium oxide nanoparticles reduce steatosis, portal hypertension and display anti-inflammatory properties in rats with liver fibrosis

BACKGROUND & AIMS

Cerium oxide nanoparticles (CeO2NPs) have proven to behave as free radical scavengers and/or anti-inflammatory agents. The aim of the study was to determine whether CeO2NPs display hepatoprotective properties in experimental chronic liver disease.

METHODS

Systemic and hepatic effects of nanoparticles were assessed in CCl4-treated rats receiving CeO2NPs or vehicle twice weekly for two weeks and CCl4 treatment was continued for 8 additional weeks. Thereafter, mean arterial pressure and portal pressure (PP) were assessed and serum samples obtained to measure standard hepatic and renal function tests. Organ and subcellular distribution of NPs were assessed using mass spectrometry (ICP-MS) and transmission electron microscopy. Liver samples were obtained to evaluate steatosis, α-SMA expression, macrophage infiltration, apoptosis and mRNA expression of oxidative stress, inflammatory or vasoactive related genes.

RESULTS

Most CeO2NPs were located in the liver and it reduced hepatic steatosis, ameliorated systemic inflammatory biomarkers and improved PP without affecting mean arterial pressure. In addition, a marked reduction in mRNA expression of inflammatory cytokines (TNFα, IL1β, COX-2, iNOS), ET-1 and messengers related to oxidative (Epx, Ncf1, Ncf2) or endoplasmic reticulum (Atf3, Hspa5) stress signaling pathways was observed in the liver of rats receiving CeO2NPs. This was associated with reduced macrophage infiltration and reduced abundance of caspase-3, α-SMA and inflammatory cytokines.

CONCLUSIONS

CeO2NPs administration to CCl4-treated rats protects against chronic liver injury by reducing liver steatosis and portal hypertension and markedly attenuating the intensity of the inflammatory response, thereby suggesting that CeO2NPs may be of therapeutic value in chronic liver disease.

Endothelin 1 and transforming growth factor-β1 correlate with liver function and portal pressure in cirrhotic patients

OBJECTIVE

The invasive measurement of hepatic venous pressure gradient is the recommended method for the assessment of portal hypertension. We assessed if the mediators that regulate portal hypertension may be used as noninvasive markers of portal hypertension and liver insufficiency.

MATERIALS AND METHODS

We explored in prospective, observational study the concentration of endothelin-1, nitric oxide, and transforming growth factor-β1/2 in peripheral and hepatic venous blood; their relationship with the values of portal hypertension and liver insufficiency; and their level changes 4-6 months after non-selective beta-blocker therapy in cirrhotic patients with non-bleeding esophageal varices.

RESULTS

(1) Cirrhotics have significantly increased peripheral endothelin 1 and decreased transforming growth factor-β1 levels; (2) peripheral levels of all factors correlated significantly with their hepatic levels; (3) after therapy, peripheral endothelin-1 levels significantly increased, but transforming growth factor-β2 levels decreased and were lower in patients with pressure gradient value normalization; (4) before and after therapy, peripheral and hepatic endothelin-1, transforming growth factor-β1/2 levels correlated significantly with liver failure indicators (laboratory parameters, Child-Pough and MELD scores) and pressure gradient values.

CONCLUSIONS

Peripheral endothelin-1 and transforming growth factor-β1 levels, which strongly correlate with their hepatic levels, reflect the stage of portal hypertension and liver insufficiency in cirrhosis.

Evolution in the understanding of the pathophysiological basis of portal hypertension: How changes in paradigm are leading to successful new treatments

Among the common complication of cirrhosis portal hypertension witnessed a major improvement of prognosis during the past decades. Principally due to the introduction of rational treatments based on new pathophysiological paradigms (concepts of thought) developed in the 1980s. The best example being the use of non-selective beta-blockers and of vasopressin analogs, somatostatin, and its analogs. Further refinement in the knowledge of the molecular mechanisms involved in the regulation of both the splanchnic and hepatic circulation has led to the emergence of new treatments, which are based on evidence that show not only structural but also vasoactive components increase the hepatic vascular resistance, as well as of angiogenesis. This knowledge and future improvements will most likely result in more effective treatment of portal hypertension and effective prevention of its complications in early stages.

The phosphodiesterase-5-inhibitor udenafil lowers portal pressure in compensated preascitic liver cirrhosis. A dose-finding phase-II-study

BACKGROUND

Phosphodiesterase-5-inhibitors may lower portal pressure.

AIMS

To investigate the effect of the phosphodiesterase-5-inhibitor udenafil on hepatic and systemic haemodynamics in liver cirrhosis.

METHODS

In an open-label phase-II-study, patients with liver cirrhosis Child A/B and hepatic venous pressure-gradient ≥ 12 mmHg received 12.5mg/day, 25mg/day, 50mg/day, 75 mg/day (n = 5, each), or 100mg/day (n = 10) udenafil p.o. for one week. On days 0 and 6, hepatic venous pressure-gradient was measured prior to and one hour after drug ingestion. Endpoints were reduction of hepatic venous pressure-gradient from day 0 pre to day 6 post intake and reduction in the acute setting. Pharmacokinetics were measured in the two lowest dosage groups.

RESULTS

Combining the 75 and 100mg/day groups hepatic venous pressure-gradient reduction after drug intake was 19.9% (p = 0.0006) on day 0. From day 0 pre-dose to day 6 post-dose hepatic venous pressure-gradient decreased by 15.7% (p = 0.040) and in 5/15 patients by ≥ 20% or to <12 mmHg. In the 100mg/day group, mean arterial pressure decreased from 98.9 mmHg by 6.2 mmHg (p = 0.037) from day 0 pre-dose to day 6 post-dose. Heart rates or electrocardiograms were unchanged. Udenafil was eliminated with t1/2 = 25 h.

CONCLUSIONS

Oral application of 75-100mg of the phosphodiesterase-5-inhibitor udenafil lowers portal pressure in the acute setting by about 20% without relevant systemic cardiovascular side effects.

Pharmacologic management of portal hypertension

Progress in the knowledge of the pathophysiology of portal hypertension has disclosed new targets for therapy, resulting in a larger spectrum of drugs with a potential role for clinical practice. This review focuses on pharmacologic treatments already available for reducing portal pressure and summarizes drugs currently under investigation in this field.

Comprehensive Predictors of Portal Pressure from Functional Liver Reserve in Patients Who Underwent Hepatectomy

Portal hypertension is a major risk factor for hepatic failure or intestinal bleeding in patients with liver disease but cannot be measured indirectly. We attempted to comprehensively evaluate preoperative parameters of functional liver reserve that correlated with portal pressure (PP) in patients with various liver diseases. We examined 93 patients in whom portal pressure was directly measured during preoperative portal vein embolization (PVE) or operation. Background liver included chronic viral liver disease in 43 patients, obstructive jaundice in 29 patients, and normal liver in 21. Multivariate logistic analysis and linear regression analysis were applied to create a predictive formula for PP. Mean PP was 13.4 ± 4.9 cm H2O, and PP was significantly associated with severity of liver injury, hepatic fibrosis, intraoperative blood loss, and post-hepatectomy morbidity (p < 0.05 each). Mean PP after PVE (22.5 ± 7.8 cm H2O) was significantly increased compared to that before embolization (13.1 ± 4.7 cm H2O; p < 0.01). Univariate analysis identified seven significant parameters of preoperative liver function associated with PP: indocyanine green (ICG) test result, liver uptake and clearance index (HH15) on (99m)Tc-galactosyl serum albumin liver scintigraphy, total bilirubin level, prothrombin activity, and hyaluronate level. Using multiple linear regression analysis, the predictive formula using ICG and HH15 was as follows: Y (estimated PP) = 0.273 + 0.086 × ICGR15 + 0.193 × HH15. The calculated PP (11.5 ± 4.6 cm H2O (-1.9 cm H2O)) was lower than true PP, which was significantly associated with post-hepatectomy morbidity (p < 0.05). The correlation between true and calculated PP was weak, and prediction using the conventional liver functional parameters was limited at present and, however, estimating PP appears to be useful in evaluating portal hypertension and post-hepatectomy morbidity.

Fenofibrate A peroxisome proliferator activated receptor-α agonist treatment ameliorates Concanavalin A-induced hepatitis in rats

Peroxisome proliferator-activated receptor-α (PPARα) is physiologically highly expressed by hepatocytes, where it plays a pivotal anti-inflammatory and metabolic role. The decrease expression and functional activity of PPARα in hepatocytes during hepatitis C virus infection may contribute to the pathogenesis of the disease in humans. This study aims at evaluating the effects of PPARα activation with fenofibrate (FF) on liver inflammation, fibrosis and portal pressure (PP) in Concanavalin A (Con A)- induced hepatitis in rats. The rats were randomly divided to 3 groups; control (1 ml saline iv/wk) group, Con A (20mg/kg/iv/wk) group and Con A with FF (100mg/kg/day p.o) group. Blood samples and livers were collected by the end of the first, second, fourth and eighth injections of Con A for biochemical, histopathological and immunohistochemistry studies for α-smooth muscle actin (α SMA). Measurement of PP was performed by the end of the 8th week. FF group had a significant (P<0.05) decrease of serum alanine and aspartate aminotransferases with significant reduction of hepatic tumor necrosis factor alpha and malondialdehyde levels than Con A group. Histopathological examination revealed that treatment with FF significantly suppressed early inflammation, reduced α SMA, and apoptosis of hepatocytes induced by Con A, thereby preventing the progression of chronic liver injury and fibrosis. In addition FF group had a significantly lower PP (-89.0%) than Con A group. In conclusion PPARα activation significantly reduced liver inflammation, fibrosis and PP in Con A model of hepatitis that may represent a new therapeutic strategy for hepatitis and its complications.

Use of portal pressure studies in the management of variceal haemorrhage

Portal hypertension occurs as a complication of liver cirrhosis and complications such as variceal bleeding lead to significant demands on resources. Endoscopy is the gold standard method for screening cirrhotic patients however universal endoscopic screening may mean a lot of unnecessary procedures as the presence of oesophageal varices is variable hence a large time and cost burden on endoscopy units to carry out both screening and subsequent follow up of variceal bleeds. A less invasive method to identify those at high risk of bleeding would allow earlier prophylactic measures to be applied. Hepatic venous pressure gradient (HVPG) is an acceptable indirect measurement of portal hypertension and predictor of the complications of portal hypertension in adult cirrhotics. Varices develop at a HVPG of 10-12 mmHg with the appearance of other complications with HPVG > 12 mmHg. Variceal bleeding does not occur in pressures under 12 mmHg. HPVG > 20 mmHg measured early after admission is a significant prognostic indicator of failure to control bleeding varices, indeed early transjugular intrahepatic portosystemic shunt (TIPS) in such circumstances reduces mortality significantly. HVPG can be used to identify responders to medical therapy. Patients who do not achieve the suggested reduction targets in HVPG have a high risk of rebleeding despite endoscopic ligation and may not derive significant overall mortality benefit from endoscopic intervention alone, ultimately requiring TIPS or liver transplantation. Early HVPG measurements following a variceal bleed can help to identify those at risk of treatment failure who may benefit from early intervention with TIPS. Therefore, we suggest using HVPG measurement as the investigation of choice in those with confirmed cirrhosis in place of endoscopy for intitial variceal screening and, where indicated, a trial of B-blockade, either intravenously during the initial pressure study with assessment of response or oral therapy with repeat HVPG six weeks later. In those with elevated pressures, primary medical prophylaxis could be commenced with subsequent close monitoring of HVPG thus negating the need for endoscopy at this point. All patients presenting with variceal haemorrhage should undergo HVPG measurement and those with a gradient greater than 20 mmHg should be considered for early TIPS. By introducing portal pressure studies into a management algorithm for variceal bleeding, the number of endoscopies required for further intervention and follow up can be reduced leading to significant savings in terms of cost and demand on resources.

Early primary prophylaxis with beta-blockers does not prevent the growth of small esophageal varices in cirrhosis: a randomized controlled trial

BACKGROUND

The efficacy of portal pressure reduction by beta-blockers and the utility of serial hepatic venous pressure gradient (HVPG) measurements for the management of small (≤5 mm) esophageal varices in patients of cirrhosis are not clear.

AIMS

The study had the following aims: to study (1) the effect of propranolol on the growth of small varices and (2) whether single or serial HVPG measurements result in a better outcome compared to no measurement in patients with small varices.

METHODS

Consecutive cirrhosis patients with small varices, without any history of variceal bleed, were randomized to receive propranolol or placebo and to undergo no HVPG, only baseline HVPG, or serial HVPG measurements.

RESULTS

A total of 150 cirrhotics (cirrhosis predominantly viral or alcohol induced) were included (77 in the beta-blocker and 73 in the placebo group). Baseline characteristics were similar. The actuarial 2-year risk of growth of varices (primary endpoint) was 11 and 16% in the propranolol and placebo group, respectively (P = 0.786). Variceal bleeding and mortality were also comparable in the two groups. Similarly, the outcome was not influenced by HVPG measurements (whether serial, only baseline, or no HVPG). A bilirubin level of ≥1.5 mg/dl was found to be an independent predictor of variceal progression.

CONCLUSIONS

In cirrhotics with small esophageal varices, nonselective beta-blockers are unable to prevent the growth of varices, variceal bleed, or mortality. HVPG monitoring of these patients did not change the outcome; however, the role of HVPG-guided therapy modification needs to be studied.

Effect of long-acting octreotide on portal hypertension in rats with liver fibrosis

AIM: To observe the effect of long-acting release octreotide (Sandostatin LAR) on the genesis of portal hypertension in rats with liver fibrosis induced by carbon tetrachloride (CCl₄).

METHODS: Forty SD rats were assigned randomly into 3 groups: normal control group (n = 8), fibrosis with portal hypertension group (n = 16) and Sandostatin LAR group (n = 16). Except those in the normal control group, the rats in the remaining two groups were subcutaneously injected with 400 mL/L CCl₄ (3 mL/kg) for induction of fibrosis with portal hypertension. Sandostatin LAR (0.8 mg/kg) was used intramuscularly once every 4 weeks. After 8 weeks, the pressures of portal vein were measured before pathological evaluation including macroscopic features of the liver, and plasma glucagon as well as endothelin was determined by radioimmunoassay.

RESULTS: The portal pressure, plasma glucagon and endothelin levels were significantly lower in the Sandostatin LAR group than those in the fibrosis with portal hypertension group (t = 2.5, P < 0.05; t = 2.088, P < 0.05; t = 2.102, P < 0.05), but still higher than those in the normal control group (t = 5.152, P < 0.01; t = 2.896, P < 0.01; t = 2.770, P < 0.05). In the normal control group, liver morphology and histology were had no abnormal changes; in the fibrosis with portal hypertension group and Sandostatin LAR group, fibrotic changes were observed, and moreover, the severity was higher in the former group (P < 0.05).

CONCLUSION: Long-acting octreotide can remarkably decrease the pressures of portal vein, which may be attributed to reduced liver fibrosis and decreased plasma glucagon and endothelin levels.

Role of echo Doppler ultrasonography in the evaluation of postprandial hyperemia in cirrhotic patients

AIM: To assess the role of echo-Doppler ultrasonography in postprandial hyperemia in cirrhotic patients by comparing the results with the hepatic vein catheterization technique.

METHODS: Patients with cirrhosis, admitted to the portal hemodynamic laboratory were included into the study. After an overnight fast, echo-Doppler ultrasonography (basal and 30 min after a standard meal) and hemodynamic studies by hepatic vein catheterization (basal, 15 min and 30 min after a standard meal) were performed. Ensure Plus (Abbot Laboratories, North Chicago, IL) was used as the standard liquid meal. Correlation analysis of the echo-Doppler and hepatic vein catheterization measurements were done for the basal and postprandial periods.

RESULTS: Eleven patients with cirrhosis (5 Child A, 4 Child B, 2 Child C) were enrolled into the study. After the standard meal, 8 of the 11 patients showed postprandial hyperemia with increase in portal blood flow, portal blood velocity and hepatic venous pressure gradient. Hepatic venous pressure gradient in the postprandial period correlated positively with postprandial portal blood velocity (r = 0.8, P < 0.05) and correlated inversely with postprandial superior mesenteric artery pulsatility index (r = -1, P < 0.01).

CONCLUSION: Postprandial hyperemia can be efficiently measured by echo-Doppler ultrasonography and the results are comparable to those obtained with the hemodynamic studies.