Invasive and non-invasive assessment of portal hypertension

Heparin is an effective treatment for preventing liver failure after hepatectomy

BACKGROUND

Posthepatectomy liver failure (PHLF) is one of the most important causes of death following liver resection. Heparin, an established anticoagulant, can protect liver function through a number of mechanisms, and thus, prevent liver failure.

AIM

To look at the safety and efficacy of heparin in preventing hepatic dysfunction after hepatectomy.

METHODS

The data was extracted from Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) v1. 4 pinpointed patients who had undergone hepatectomy for liver cancer, subdividing them into two cohorts: Those who were injected with heparin and those who were not. The statistical evaluations used were unpaired t-tests, Mann-Whitney U tests, chi-square tests, and Fisher's exact tests to assess the effect of heparin administration on PHLF, duration of intensive care unit (ICU) stay, need for mechanical ventilation, use of continuous renal replacement therapy (CRRT), incidence of hypoxemia, development of acute kidney injury, and ICU mortality. Logistic regression was utilized to analyze the factors related to PHLF, with propensity score matching (PSM) aiming to balance the preoperative disparities between the two groups.

RESULTS

In this study, 1388 patients who underwent liver cancer hepatectomy were analyzed. PSM yielded 213 matched pairs from the heparin-treated and control groups. Initial univariate analyses indicated that heparin potentially reduces the risk of PHLF in both matched and unmatched samples. Further analysis in the matched cohorts confirmed a significant association, with heparin reducing the risk of PHLF (odds ratio: 0.518; 95% confidence interval: 0.295-0.910; P = 0.022). Additionally, heparin treatment correlated with improved short-term postoperative outcomes such as reduced ICU stay durations, diminished requirements for respiratory support and CRRT, and lower incidences of hypoxemia and ICU mortality.

CONCLUSION

Liver failure is an important hazard following hepatic surgery. During ICU care heparin administration has been proved to decrease the occurrence of hepatectomy induced liver failure. This indicates that heparin may provide a hopeful option for controlling PHLF.

Clinical implementation of partial splenic artery embolization for the prevention of recurrent bleeding from esophageal varices in portal hypertension

OBJECTIVE

Aim: To evaluate the effectiveness of PSAE for secondary prevention of VB episodes in patients with chronic liver disease (CLD) and CSPH.

PATIENTS AND METHODS

Materials and Methods: One hundred twenty patients (from 2008 to 2020) were submitted of PSAE as secondary prevention treatment. The results of the treatment of 27 patients between 2008 and 2012 (first period) were compared with those of 93 patients treated with PSAE since 2013 (second period), as procedure and management protocol were modificated. VB recurrence rate and mortality (related and non-related to bleeding episodes) were defined as study end-points in both groups at 12-months follow-up.

RESULTS

Results: At 12-months follow-up, 11 (40,7 %) and 54 (58,1 %) patients in groups 1 and 2, respectively, were free from VBs (p=0,129). Overall mortality rate was significantly higher in group 1, as compared to group 2: 10 (37,0 %) versus 6 (6,4 %) patients, respectively (p<0,001), - due to higher frequency of fatal VB events (7 (26,0 %) vs. 3 (3,2 %) patients, respectively; p=0,001).

CONCLUSION

Conclusions: PSAE is an effective treatment for secondary prevention of VB in patients with CLD and CSPS. The management protocol modification resulted in the decrease in overall mortality rate and mortality related to recurrent VB episodes.

Development of a Direct Non-Puncture Device for Measuring Portal Venous Pressure during Liver Transplantation-A Swine Model

Portal hypertension-related complications pose a significant risk for liver failure post-transplantation. Thus, accurate monitoring of intraoperative portal venous pressure (PVP) is crucial. However, current PVP monitoring techniques requiring direct percutaneous puncture carry the risk of graft damage. In this study, we present an innovative non-puncture PVP monitoring device (PVPMD) using a 3D-printed prototype. PVPMD design is inspired by the sphygmomanometer principle, and strategically encompasses the portal vein and enables precise PVP measurement through blood flow ultrasonography after temporary occlusion. By a series of mini-pig experiments, the prototype PVPMD demonstrated a strong correlation with invasive catheter measurements in the main trunk of the portal vein (rs = 0.923, p = 0.000). There was a significant repeatability and reproducibility between the prototype PVPMD- and invasive catheter-measured PVP. This indicates that the PVPMD holds immense potential for direct application in liver transplantation and surgery. Moreover, it has the potential to replace catheter-based central venous pressure (CVP) measurements, thereby mitigating catheter-related complications during many surgeries. In conclusion, our innovative device represents a significant advancement in PVP monitoring during liver transplantation, with comprehensive validation from principle exploration to successful animal experiments. We anticipate that this groundbreaking PVPMD will attract the attention of researchers and clinicians, propelling the noninvasive measurement of PVP or other venous/arterial pressures into a new era of clinical practice.

Methods for assessing portal hypertension

Many researchers and clinicians have taken the value of hepatic venous pressure gradient (HVPG) as an essential prognostic factor in subjects with chronic liver diseases. HVPG ≥ 10 mmHg indicates the presence of clinically significant portal hypertension, the main predictor of the risk of variceal bleeding, hepatic decompensation, and mortality. However, HVPG measurement is invasive and requires high expertise, so its routine use outside tertiary care centers or clinical trials is limited. Clinically significant portal hypertension also might be detected using non-invasive options such as ultrasonography, elastography, magnetic resonance imaging, and indices derived from laboratory parameters. Our review aims to present the feasibility and applicability of HVPG in modern clinical practice in patients with liver cirrhosis, including invasive and non-invasive methods, based on literary sources from the MEDLINE database.

Beyond conventional physical examination in hepatology: POCUS

Point-of-care ultrasound (POCUS) refers to the use of ultrasound imaging through pocket-sized sonographic devices at the patient's bedside, to make a diagnosis or direct a procedure and immediately answer a clinical question. Its goal is to broaden the physical examination, not to replace conventional ultrasound studies. POCUS has evolved as a complement to physical examination and has been adopted by different medical specialties, including hepatology. A narrative synthesis of the evidence on the applications of POCUS in hepatology was carried out, describing its usefulness in the diagnosis of cirrhosis of the liver, metabolic dysfunction-associated steatotic liver disease (MASLD), decompensated cirrhosis, and portal hypertension. The review also encompasses more recent applications in the hemodynamic evaluation of the critically ill patient with cirrhosis of the liver, patients with other liver diseases, as well as in the ultrasound guidance of procedures. POCUS could make up part of the daily clinical practice of gastroenterologists and hepatologists, simplifying the initial evaluation of patients and optimizing clinical management. Its accessibility, ease of use, and low adverse event profile make POCUS a useful tool for the properly trained physician in the adequate clinical setting. The aim of this review was to describe the available evidence on the usefulness of POCUS in the daily clinical practice of gastroenterologists and hepatologists.

Non-invasive diagnosis and follow-up of portal hypertension

Compensated advanced chronic liver disease (cACLD) describes the spectrum of advanced fibrosis/cirrhosis in asymptomatic patients at risk of developing clinically significant portal hypertension (CSPH, defined by a hepatic venous pressure gradient (HVPG) ≥10 mmHg). Patients with cACLD are at high risk of liver-related morbidity and mortality. In patients at risk of chronic liver disease, cACLD is strongly suggested by a liver stiffness (LSM) value >15 kPa or clinical/biological/radiological signs of portal hypertension, and ruled out by LSM <10 kPa, or Fibrotest® ≤0.58, or Fibrometer® ≤0.786. Patients with chronic liver disease (excluding vascular diseases) with a LSM <10 kPa are at low risk of developing portal hypertension complications. The presence of CSPH can be strongly suspected when LSM is ≥20 kPa. In a patient without clinical, endoscopic or radiological features of portal hypertension, measurement of the HVPG is recommended before major liver or intra-abdominal surgery, before extra-hepatic transplantation and in patients with unexplained ascites. Endoscopic screening for oesophageal varices can be avoided in patients with LSM <20 kPa and a platelet count >150 G/L (favourable Baveno VI criteria) at the time of diagnosis. There is no non-invasive method alternative for oeso-gastroduodenal endoscopy in patients with unfavourable Baveno criteria (liver stiffness ≥20 kPa or platelet count ≤50 G/l). Platelet count and liver stiffness measurements must be performed once a year in patients with cACLD with favourable Baveno VI criteria at the time of diagnosis. A screening oeso-gastroduodenal endoscopy is recommended if Baveno VI criteria become unfavourable.

Impact of sustained virologic response in regression of portal hypertension in Egyptian patients with hepatitis C virus-associated cirrhosis and portal hypertension

Background

Portal hypertension (PH) is a common consequence in hepatitis C virus cirrhotic patients. With interferon alpha-based therapy, SVR was linked to improved PH and fibrosis regression. SVR to oral antiviral regimens is linked to reduced portal pressure in patients with clinically significant portal hypertension (CSPH) at baseline. However, CSPH continues in most of the patients. This study aims to assess the reversibility and/or improvement of PH in Egyptian patients with HCV-related cirrhosis and CSPH after achieving SVR with DAAs. The second aim is to evaluate performance of the noninvasive markers of fibrosis in prediction of the presence and/or reversibility of the CSPH in correlation to radiological and endoscopic parameters.

Subjects and methods

We evaluated noninvasive parameters, radiological and endoscopic signs of PH at baseline, and/or SVR 24 and SVR 48 post-DAA therapy in 40 patients with cirrhosis and CSPH (group A) and another 40 patients with cirrhosis only (group B).

Results

In group A, the spleen diameter decreased from baseline (15.74 ± 1.53 cm), and SVR 24 (15.48 ± 1.51), to SVR 48 (15.35 ± 1.49 cm). No ascites detected at SVR 48 in 62.5%. Portal vein diameter and portal vein blood velocity reduced to 13.53 ± 1.07 mm and 14.14 ± 2.2 cm/s at SVR 48, with reversibility of hepatic vein waveform towards the triphasic pattern. Medium to large esophageal varices regressed from 52.5% to 2.5%, and up to 70% of patients showed no EVs at SVR 48. In group A, 24 patients showed complete reversibility of CSPH, and 16 patients showed improvement of CSPH. Child-Pugh score, FIB-4 index, King’s score, and Lok index revealed higher significance for detection of the presence of PH. Child-Pugh score, PC/SD ratio, and Lok index revealed higher significance for detection of reversibility of PH.

Conclusion

We concluded that CSPH improved after SVR with DAAs and completely regressed in some patients. Upon predicting the presence of PH, Child-Pugh score, FIB-4 index, King’s score, and Lok index were the most significant noninvasive scores. While for predicting the reversibility of PH, Child-Pugh score, PC/SD ratio, and Lok index were the most significant scores.

Overlooked subclinical portal hypertension in non-cirrhotic NAFLD: Is it real and how to measure it?

Clinical and experimental advances related to the detection, magnitude and pathobiology of subclinical portal hypertension in non-alcoholic fatty liver disease (NAFLD), primarily observed in the presence of non-alcoholic steatohepatitis (NASH), prompt us to revisit current disease paradigms. Hepatic venous pressure gradient (HVPG) has been reported to underestimate portal pressure in NASH-related cirrhosis, while inaccuracy is more likely in non-cirrhotic livers, indicating a potential need for new and preferably non-invasive methods of measurement. Although clinically significant portal hypertension (HVPG ≥10 mmHg) retains its prognostic significance in NASH, subclinical portal hypertension (HVPG 6.0-9.5 mmHg) has been repeatedly detected in patients with NAFLD in the absence of cirrhosis or even significant fibrosis whereas the impact of these findings on disease outcomes remains unclear. Mechanocrine signalling pathways in various types of liver cell reveal a molecular basis for the adverse effects of subclinical portal hypertension and suggest a bidirectional relationship between portal pressure and fibrosis. These findings may guide efforts to improve risk assessment and identify novel therapeutic targets in NAFLD.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Interventions in Portal Hypertension and Its Complications

Portal hypertension is a complication of chronic liver disease. Various radiological interventions are being done to aid in the diagnosis of portal hypertension; further, an interventional radiologist can offer various treatments for the complications of portal hypertension. Diagnosis of portal hypertension in its early stage may require hepatic venous pressure gradient measurement. Measurement of gradient also guides in diagnosing the type of portal hypertension, measuring response to treatment and prognostication. This article attempts to provide evidence-based guidelines on the management of portal hypertension and treatment of its complications.

Hepatectomy-Induced Alterations in Hepatic Perfusion and Function - Toward Multi-Scale Computational Modeling for a Better Prediction of Post-hepatectomy Liver Function

Liver resection causes marked perfusion alterations in the liver remnant both on the organ scale (vascular anatomy) and on the microscale (sinusoidal blood flow on tissue level). These changes in perfusion affect hepatic functions via direct alterations in blood supply and drainage, followed by indirect changes of biomechanical tissue properties and cellular function. Changes in blood flow impose compression, tension and shear forces on the liver tissue. These forces are perceived by mechanosensors on parenchymal and non-parenchymal cells of the liver and regulate cell-cell and cell-matrix interactions as well as cellular signaling and metabolism. These interactions are key players in tissue growth and remodeling, a prerequisite to restore tissue function after PHx. Their dysregulation is associated with metabolic impairment of the liver eventually leading to liver failure, a serious post-hepatectomy complication with high morbidity and mortality. Though certain links are known, the overall functional change after liver surgery is not understood due to complex feedback loops, non-linearities, spatial heterogeneities and different time-scales of events. Computational modeling is a unique approach to gain a better understanding of complex biomedical systems. This approach allows (i) integration of heterogeneous data and knowledge on multiple scales into a consistent view of how perfusion is related to hepatic function; (ii) testing and generating hypotheses based on predictive models, which must be validated experimentally and clinically. In the long term, computational modeling will (iii) support surgical planning by predicting surgery-induced perfusion perturbations and their functional (metabolic) consequences; and thereby (iv) allow minimizing surgical risks for the individual patient. Here, we review the alterations of hepatic perfusion, biomechanical properties and function associated with hepatectomy. Specifically, we provide an overview over the clinical problem, preoperative diagnostics, functional imaging approaches, experimental approaches in animal models, mechanoperception in the liver and impact on cellular metabolism, omics approaches with a focus on transcriptomics, data integration and uncertainty analysis, and computational modeling on multiple scales. Finally, we provide a perspective on how multi-scale computational models, which couple perfusion changes to hepatic function, could become part of clinical workflows to predict and optimize patient outcome after complex liver surgery.

Nomogram for hepatic venous pressure gradient in patients with cirrhosis

OBJECTIVE

The hepatic venous pressure gradient (HVPG) plays an important role in the treatment and prognosis of patients with cirrhosis. Our study aimed to develop and validate a nomogram for an HVPG >12 mmHg.

METHODS

A retrospective study was performed to create a nomogram for an HVPG >12 mmHg in a training cohort that was validated in another cohort. The discriminatory ability and calibration of the nomogram were tested using the C-statistic, area under the receiver operating characteristic curve (AUROC) and calibration plots.

RESULTS

The nomogram was based on portosystemic shunts identified on computed tomography images, the etiology of cirrhosis and the Child-Pugh grade. These parameters were significantly associated with an HVPG >12 mmHg (P < 0.05 for both the training and validation cohorts). In the training cohort, the model showed good discrimination (C-statistic, AUROC, and R² of 0.71, 0.71 and 0.13, respectively) and good calibration. The total cutoff value was 112 and the sensitivity and specificity were 57.1% and 77.6%, respectively. The application of the nomogram in the validation cohort still yielded good discrimination (C-statistic 0.75 [95% confidence interval 0.61-0.89], AUROC 0.75, and R² 0.16) and good calibration.

CONCLUSIONS

This nomogram is a convenient tool for predicting an HVPG >12 mmHg in patients with cirrhosis and can help clinicians quickly identify patients with decompensated cirrhosis.

Portal vein thrombosis associated with high 14-day and 6-week rebleeding in patients after oesophageal variceal band ligation: a retrospective, multicentre, nested case-control study

BACKGROUND AND AIMS

The association between prognosis of variceal bleeding and portal vein thrombosis (PVT) is unclear. In this multicentre study, we determined the effect of PVT on rebleeding and mortality in patients with acute variceal bleeding (AVB) after oesophageal variceal band ligation (EVL).

METHODS

Cirrhotic patients with AVB who had undergone EVL were included. The patients were allocated to either the PVT group or the control cirrhotic group (CCG) based on the presence or absence of PVT. One-year rebleeding episodes and mortality after EVL were recorded.

RESULTS

A total of 218 cirrhotic patients with AVB from 3 centres were included. Patients with PVT had a higher rate of 14-day and 6-week rebleeding than those without PVT (14-day: 8.26% vs. 1.83%, p = 0.03; 6-week: 11.92% vs. 1.83%, p = 0.003). The rates of 5-day failure (3.67% vs. 0.92%, p = 0.175), 1-year rebleeding (21.10% vs. 20.18%, p = 0.867), and 14-day, 6-week, and 1-year mortality were similar between the groups (14-day: 3.67% vs. 0.92%, p = 0.175; 6-week: 3.67% vs. 0.92%, p = 0.175; 1-year: 3.67% vs. 1.83%, p = 0.408). The Child-Pugh class [p = 0.022, hazard ratio (HR): 1.453; 95% confidence interval (CI) 1.056-1.998], PVT (p = 0.050, HR: 4.622, 95% CI 0.999-21.395), albumin < 30 g/L (p = 0.023, HR: 5.886, 95% CI 1.272-27.245), and number of bands (p = 0.010, HR: 1.207, 95% CI 1.046-1.393) were identified as the predictors for 14-day rebleeding; the multivariate analysis revealed only the number of bands (p = 0.009, HR: 1.247, 95% CI 1.056-1.473) as the independent factor. PVT (p = 0.012, HR: 6.732, 95% CI 1.519-29.835) and albumin < 30 g/L (p = 0.027, HR: 3.643, 95% CI 1.160-11.441) were identified as predictors for 6-week rebleeding; however, only PVT (p = 0.015, HR: 6.380, 95% CI 1.427-28.515) was found to be the independent factor in the multivariate analysis. Further analysis showed that superior mesenteric vein (SMV) thrombosis is the only risk factor predicting 6-week rebleeding in patients with PVT (p = 0.032, HR: 3.405, 95% CI 1.112-10.429).

CONCLUSIONS

PVT was associated with high 14-day and 6-week rebleeding in patients after EVL. SMV thrombosis was the only risk factor for 6-week rebleeding in patients with PVT. High albumin levels may serve as a protective factor for the 14-day and 6-week rebleeding risk. PVT was not responsible for mortality after EVL during 1-year follow-up.

[¹¹C] choline as a potential PET/CT biomarker of liver cirrhosis: A prospective pilot study

AIM OF THE STUDY

To compare [¹¹C] choline PET/CT findings between patients with cirrhosis and normal liver controls.

METHODS

Included 11 patients with cirrhosis and 14 controls. All underwent a dynamic [11C] choline PET/CT. The maximal standard uptake values (SUVmax), the area under the curve (AUC) and kinetic parameters (K1 and K2), clinical and laboratory data, were compared between groups.

RESULTS

Patients mean age was 68.4 ± 10.7 and controls, 69.7 ± 7.3 years. Mean SUVmax was higher in patients than controls (right lobe, 10.06 ± 12 vs. 6.3 ± 1.6, P = 0.011; left lobe, 8.6 ± 11.6 vs. 5.4 ± 0.9, P = 0.024; spleen 17.99 ± 27.8 vs. 13.4 ± 2.6, P = 0.027; kidney, 35.9 ± 59.5 vs. 19.3 ± 4.8, P = 0.025) and also AUC values (right lobe, 13,538 ± 20,020 vs. 8427.3 ± 1557.9, P = 0.026; left lobe 12,304 ± 18,871 vs. 6878.9 ± 1294.3, P = 0.024; spleen, 12,875 ± 17,930 vs. 8263.9 ± 1279.2, P = 0.023; kidney, 24,623 ± 36,025 vs. 13,667 ± 3873.9, P = 0.032). No difference in kinetic parameters was found. No correlations between severity of clinical signs and imaging-derived parametric data were found among patients with cirrhosis.

CONCLUSIONS

[11C] choline PET/CT may serve as a noninvasive biomarker for patients with cirrhosis.

Spleen Stiffness Predicts Survival after Transjugular Intrahepatic Portosystemic Shunt in Cirrhotic Patients

Objectives

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective intervention for portal hypertensive complications. Little is known about the ability of spleen stiffness (SS) for predicting the survival of cirrhotic patients undergoing TIPS. This study is to evaluate the influence of SS detected by point shear wave elastography (pSWE) in predicting survival after TIPS.

Methods

This retrospective cohort study screened consecutive patients who underwent TIPS and reliable pSWE measurement between October 2014 and September 2017 from our prospectively maintained database. SS values were measured before TIPS. The primary endpoint was the overall survival after TIPS. The Cox regression analysis model was used for univariate and multivariate analyses. A receiver operating characteristic (ROC) curve analysis was performed to calculate the sensitivity, specificity, and positive and negative predictive values.

Results

A total of 89 patients were involved in the final analysis. 24 patients (27.0%) died during a median follow-up time of 31 m. Multivariable Cox regression analysis confirmed that higher SS value (P < 0.001), LS value (P = 0.008), diameter of shunt (P = 0.001), and older age (P < 0.001) were independent prognostic factors of survival after TIPS. The risk of death rose 57.440-fold for each SS unit (m/s) increase. SS was also correlated with liver failure after TIPS. ROC analysis showed that the best SS cutoff value was 3.60 m/s for predicting survival, with a sensitivity of 54.2% and specificity of 90.8%.

Conclusions

The SS value determined by pSWE in cirrhotic patients was an independent predictive factor for survival after TIPS.

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.

Management of nonalcoholic fatty liver disease in the Middle East

The prevalence of nonalcoholic fatty liver disease (NAFLD) in the Middle East is increasing in parallel to an increase in the prevalence of associated risk factors such as obesity, metabolic syndrome, and type 2 diabetes mellitus. About 20% to 30% of the patients progress to develop nonalcoholic steatohepatitis (NASH), a histological subtype of NAFLD, with features of hepatocyte injury such as hepatocyte ballooning. NASH can progress to fibrosis, cirrhosis, and even hepatocellular carcinoma. NAFLD thus causes a substantial burden on healthcare systems and it is imperative that appropriate strategies are discussed at a regional level to facilitate effective management tailored to the needs of the region. To fulfil this unmet need, expert gastroenterologists, hepatologists, and endocrinologists from the region came together in three advisory board meetings that were conducted in Saudi Arabia, United Arab Emirates, and Kuwait, to discuss current local challenges in NAFLD screening and diagnosis, and the different available management options. The experts discussed the disease burden of NAFLD/NASH in the Middle East; screening, diagnosis, and referral patterns in NAFLD; and available treatment options for NAFLD and NASH. This paper summarizes the discussions and opinion of the expert panel on the management of NAFLD/NASH and also presents an extensive literature review on the topic.

Nonalcoholic fatty liver disease and portal hypertension

Nonalcoholic fatty liver disease (NAFLD) is a substantial and growing problem worldwide and has become the second most common indication for liver transplantation as it may progress to cirrhosis and develop complications from portal hypertension primarily caused by advanced fibrosis and erratic tissue remodeling. However, elevated portal venous pressure has also been detected in experimental models of fatty liver and in human NAFLD when fibrosis is far less advanced and cirrhosis is absent. Early increases in intrahepatic vascular resistance may contribute to the progression of liver disease. Specific pathophenotypes linked to the development of portal hypertension in NAFLD include hepatocellular lipid accumulation and ballooning injury, capillarization of liver sinusoidal endothelial cells, enhanced contractility of hepatic stellate cells, activation of Kupffer cells and pro-inflammatory pathways, adhesion and entrapment of recruited leukocytes, microthrombosis, angiogenesis and perisinusoidal fibrosis. These pathological events are amplified in NAFLD by concomitant visceral obesity, insulin resistance, type 2 diabetes and dysbiosis, promoting aberrant interactions with adipose tissue, skeletal muscle and gut microbiota. Measurement of the hepatic venous pressure gradient by retrograde insertion of a balloon-tipped central vein catheter is the current reference method for predicting outcomes of cirrhosis associated with clinically significant portal hypertension and guiding interventions. This invasive technique is rarely considered in the absence of cirrhosis where currently available clinical, imaging and laboratory correlates of portal hypertension may not reflect early changes in liver hemodynamics. Availability of less invasive but sufficiently sensitive methods for the assessment of portal venous pressure in NAFLD remains therefore an unmet need. Recent efforts to develop new biomarkers and endoscopy-based approaches such as endoscopic ultrasound-guided measurement of portal pressure gradient may help achieve this goal. In addition, cellular and molecular targets are being identified to guide emerging therapies in the prevention and management of portal hypertension.

Two-dimensional Shear Wave Elastography with Propagation Maps for the Assessment of Liver Fibrosis and Clinically Significant Portal Hypertension in Patients with Chronic Liver Disease: A Prospective Study

OBJECTIVES

To investigate the diagnostic performance of liver stiffness (LS) measurements on two-dimensional (2D) shear wave elastography (SWE) for the assessment of hepatic fibrosis using LS measurements on MR elastography (MRE) as the reference standard and the prediction of clinically significant portal hypertension (CSPH).

METHODS

In this prospective study, 101 patients with chronic liver disease or cirrhosis underwent both MRE and SWE. After exclusion of technical failure on MRE (n = 5), technical failure/unreliable measurement on SWE (n = 4), LS measurements obtained on SWE with the aid of propagation maps were correlated with those of the MRE using Pearson's correlation analysis. Diagnostic performances for significant fibrosis (≥F2: MRE of ≥2.99 kPa) or cirrhosis (F4: MRE of ≥3.63 kPa) and for the prediction of CSPH were assessed using receiver operating characteristics (ROC) curve analysis.

RESULTS

LS values on SWE showed a strong correlation with those on MRE (r = 0.846, P < 0.001). For the diagnosis of significant fibrosis or cirrhosis in patients with hepatitis B virus-related liver disease (n = 75), SWE showed areas under the ROC curves (AUC) of 0.975 and 0.912, respectively (95% confidence interval [CI], 0.910-997, and 0.824-0.965). For the prediction of CSPH, the AUC of SWE was 0.818 (95% CI, 0.712-0.898), and when an LS value of 11.5 kPa was applied as a cut-off, SWE showed a sensitivity of 81.5% and a specificity of 72.9%.

CONCLUSION

LS measurements on 2D SWE were demonstrated to be well correlated with those obtained with MRE, and thus, may provide good diagnostic performance for the prediction of hepatic fibrosis and the presence of CSPH.

Confounding factors of non-invasive tests for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects at least 25% of the general adult population worldwide. Because only a fraction of the patients would develop liver-related complications, it is preferable to perform non-invasive tests as the initial assessment. This review summarizes the known and potential confounding factors that affect the performance of non-invasive tests of hepatic steatosis and fibrosis in patients with NAFLD. Clinicians may apply the knowledge and exercise caution in selecting investigations and interpreting test results when confounding factors are present.

Diagnostic accuracy of non-invasive methods detecting clinically significant portal hypertension in liver cirrhosis: a systematic review and meta-analysis

INTRODUCTION

We attempted to investigate non-invasive techniques and their diagnostic performances for evaluating clinically significant portal hypertension.

EVIDENCE ACQUISITION

The systematic search was performed on PubMed, Embase, Scopus, and Web of Science TM core index databases before 13 December 2018 restricted to English language and human studies.

EVIDENCE SYNTHESIS

Thirty-two studies were included, with total populations of 3,987. The overall pooled analysis was performed by bivariate random effect model, which revealed significantly higher sensitivity and specificity of 77.1% (95% confidence interval, 76.8-78.5%) and 80.1% (95% confidence interval, 78.2-81.9%), respectively; positive likelihood ratio (3.67), negative likelihood ratio (0.26); and diagnostic odd ratio (16.24). Additionally, the area under curve exhibited significant diagnostic accuracy of 0.871. However, notable heterogeneity existed in between studies (I2=87.1%), therefore, further subgroup analysis was performed. It demonstrated ultrasonography, elastography, biomarker, and computed tomography scan had a significant overall summary sensitivity (specificity) of 89.6% (78.9%), 81.7% (83.2%), 72.2% (76.8%), and 77.2% (81.2%), respectively. Moreover, the areas under curve values were significantly higher in elastography (0.906), followed by computed tomography scan (0.847), biomarker (0.825), and ultrasonography (0.803).

CONCLUSIONS

In future, non-invasive techniques could be the future choice of investigations for screening and diagnosis of clinically significant portal hypertension in cirrhosis. However, standardization of diagnostic indices and their cut-off values in each non-invasive method needs to be addressed.

Liver stiffness and serum markers for excluding high-risk varices in patients who do not meet Baveno VI criteria

BACKGROUND

The Baveno VI criteria for predicting esophageal varices, i.e., liver stiffness measurement (LSM) < 20 kPa and platelet (PLT) count > 150 × 10⁹/L, identify patients who can safely avoid gastroscopy screening. However, they require further refinement.

AIM

To evaluate the utility of LSM and serum markers of liver fibrosis in ruling out high-risk varices (HRV) in patients who do not meet Baveno VI criteria.

METHODS

Data from 132 patients with hepatitis B virus (HBV)-related compensated liver cirrhosis who did not meet the Baveno VI criteria were retrospectively reviewed. MedCalc 15.8 was used to calculate receiver operating characteristic (ROC) curves, and the accuracy of LSM, PLT count, aspartate aminotransferase (AST)-to-PLT ratio index, Fibrosis-4, and the Lok index in predicting HRV were evaluated according to the area under each ROC curve (AUROC). The utility of LSM, PLT, and serum markers of liver fibrosis stratified by alanine transaminase (ALT) and total bilirubin (TBil) levels was evaluated for ruling out HRV.

RESULTS

In all patients who did not meet the Baveno VI criteria, the independent risk factors for HRV were LSM and ALT. Only the AUROC of Lok index was above 0.7 for predicting HRV, and at a cutoff value of 0.4531 it could further spare 24.2% of gastroscopies without missing HRVs. The prevalence of HRV was significantly lower in patients with ALT or TBil ≥ 2 upper limit of normal (ULN) (14.3%) than in patients with both ALT and TBil < 2 ULN (34.1%) (P = 0.018). In the 41 patients with ALT and TBil < 2 ULN, LSM had an AUROC for predicting HRV of 0.821. LSM < 20.6 kPa spared 39.0% of gastroscopies without missing HRVs. In the 91 patients with ALT or TBiL ≥ 2 ULN, the Lok index and PLT had AUROCs of 0.814 and 0.741, respectively. Lok index ≤ 0.5596 or PLT > 100 × 10⁹/L further spared 39.6% and 43.9% of gastroscopies, respectively, without missing HRVs.

CONCLUSION

In HBV-related compensated cirrhosis patients who do not meet Baveno VI criteria, the LSM, PLT, or Lok index cutoff stratified by ALT and TBil accurately identifies more patients without HRV.

The incidence and predictors of post transarterial chemoembolization variceal bleeding in hepatocellular carcinoma patients

BACKGROUND & AIMS

Transarterial chemoembolization (TACE) is the standard of care for intermediate stage hepatocellular carcinoma (HCC) patients. Variceal bleeding is a life-threatening complication and may alter the initial treatment plan. This study was aimed to elucidate the risk factors for variceal bleeding in HCC patients receiving TACE treatment.

METHODS

From 2005 to 2016, a total of 1233 treatment-naive HCC patients receiving first time TACE treatment in Chang Gung Memorial Hospital, Linkou medical center were recruited. Pre-TACE status including baseline characteristics, prior history of ascites, and parameters for liver function evaluation were analyzed. All the variables were compared between patients with and without variceal bleeding.

RESULTS

Among the 1233 patients, the median age was 63.7 (range 25.8-91.5) years old, and 73.5% were male. Variceal bleeding events were documented in 19 patients (1.5%) within 3 months post TACE treatment. Patients with younger age, cirrhosis, pre-treatment ascites and advanced fibrosis status (higher MELD score, CTP score, ALBI grade, FIB-4 and APRI score) were more likely to encounter post-treatment variceal bleeding. Multivariate Cox regression analysis revealed existence of ascites (adjusted HR: 4.859 (1.947-12.124), p = 0.001), and higher FIB-4 score (adjusted HR: 4.481 (1.796-11.179), p = 0.001) were the independent predictive factors for variceal bleeding. Patients with post-TACE variceal bleeding are more likely to encounter tumor progression (42.1% vs. 20.3%, p = 0.039) and mortality owing to GI bleeding (15.8% vs. 3%, p = 0.032).

CONCLUSION

The incidence of post-TACE variceal bleeding was 1.5%. Patients with post-TACE variceal bleeding have poorer TACE treatment response. The pre-treatment ascites and FIB-4 score are the independent predictors for post-TACE variceal bleeding.

Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.