Hepatic venous pressure gradient measurement in clinical hepatology

Multicenter analysis on the correlation between the anatomical characteristics of hepatic veins and hepatic venous wedge pressure

BACKGROUND

Wedged hepatic venous pressure (WHVP) is a crucial variable for accurately assessing the hepatic venous pressure gradient (HVPG) and is vital for the diagnosis and prognostic evaluation of patients with portal hypertension (PH).

AIM

To investigate the anatomical characteristics of balloon-occluded hepatic venous angiography in patients with PH and analyze the relationship between the WHVP and portal venous pressure (PVP).

METHODS

This retrospective study included 877 patients with PH who met the inclusion criteria from January 2020 to June 2024. Routine and innovative hepatic venous angiography was performed during transjugular intrahepatic portosystemic shunt procedures to measure hepatic venous and PVPs. All patients' angiographic images were collected for analysis. The associations between WHVP and PVP in each group were analyzed via linear regression analysis, and a predictive model was established.

RESULTS

The 877 patients had a mean age of 52.6 ± 13.0 years, with 582 males and 295 females. Patients were categorized into four groups on the basis of their anatomical structure. All groups showed strong correlations between WHVP and PVP. The regression coefficient between the WHVP and PVP in the hepatic right vein-portal venous angiography group was 0.884 (P < 0.05); in the hepatic right vein-accessory hepatic venous angiography group, it was 0.721 (P < 0.05); in the hepatic right vein-middle hepatic venous angiography group, it was 0.344 (P < 0.05); and in the hepatic right vein-nonangiography group, it was 0.293 (P < 0.05).

CONCLUSION

The presence and anatomical classification of hepatic venous collaterals are key factors influencing the relationship between WHVP with and PVP. Based on the different anatomical classifications of hepatic veins, WHVP can be used to estimate PVP, improving the accuracy of PVP prediction.

Predictive value of hepatic venous pressure gradient in cirrhotic portal vein thrombosis development

BACKGROUND & AIMS

There are lots of risk factors reported for cirrhotic portal vein thrombosis (PVT) development, however, the relationship between hepatic venous pressure gradient (HVPG) and PVT development remains unclear.

METHODS

The clinical outcomes of cirrhotic patients who had no PVT and underwent HVPG measurement at baseline between March 2018 and March 2022 were analyzed retrospectively. Screening for non-tumoral PVT development was implemented by contrast-enhanced computed tomography and/or magnetic resonance imaging every 6-12 months.

RESULTS

Eighty-two cirrhotic patients were evaluated over a follow-up period. Of these, 12 patients (14.6%) experienced the development of PVT. The occurrence of non-tumoral PVT at one, two, and three years were 6.6%, 11.7%, and 22.2% respectively. HVPG (p=0.038;HR 1.07;95%CI 1.00-1.14) and alcohol liver disease (ALD) (p=0.019;HR 4.20;95%CI 1.27-13.89) were independently associated with a high PVT risk. The cutoff value of HVPG was 17.52 mmHg. The cumulative incidence of PVT differed significantly among groups stratified by HVPG thresholds of 16mmHg (P=0.011). The sensitivity and specificity of HVPG≥16mmHg in predicting PVT development were 100.0% and 35.7%.

CONCLUSIONS

In patients with liver cirrhosis, the value of HVPG was the independent predictive factor of PVT development. Screening for PVT was recommended during follow-up in patients with HVPG≥16 mmHg.

Reduced risk of overt hepatic encephalopathy and death after transjugular intrahepatic portosystemic shunt in patients with hepatic venovenous communications

PURPOSE

Hepatic venovenous communications (HVVC) is detectable in more than one-third of cirrhotic patients, where portal hypertension (PHT) tends to present more severely. We aimed to explore the prognostic implications of HVVC in patients with sinusoidal PHT treated by transjugular intrahepatic portosystemic shunt (TIPS).

METHOD

The multicenter data of patients (2020-2022) undergoing balloon-occluded hepatic venography during TIPS were retrospectively analyzed. Pre-TIPS total bile acids (TBA) levels in portal, hepatic and peripheral veins were compared between groups. The primary endpoint was the development of overt hepatic encephalopathy (HE) within one year after TIPS.

RESULTS

183 patients were eligible and classified by the presence (n = 69, 37.7 %) or absence (n = 114, 62.3 %) of HVVC. The agreement between wedged hepatic venous pressure and portal venous pressure was poor in HVVC group (intraclass correlation coefficients [ICC]: 0.141, difference: 13.4 mmHg, p < 0.001), but almost perfect in non-HVVC group (ICC: 0.877, difference: 0.4 mmHg, p = 0.152). At baseline, patients with HVVC had lower Model for end-stage liver disease scores (p < 0.001), blood ammonia levels (p < 0.001), TBA concentrations in the hepatic (p = 0.011) and peripheral veins (p = 0.049) rather than in the portal veins (p = 0.516), and a higher portosystemic pressure gradient (p = 0.035), suggesting more effective intrahepatic perfusion in this group. Within 1-year post-TIPS, HVVC group had a lower incidence of overt HE (11.7 % vs. 30.5 %, p = 0.004, HR: 0.34, 95 % CI: 0.16-0.74, absolute risk difference [ARD]: -17.4) and an improved liver transplantation-free survival rate (97.1 % vs. 86.8 %, p = 0.021, HR: 0.16, 95 % CI: 0.05-0.91, ARD: -10.3).

CONCLUSIONS

For patients with sinusoidal PHT treated by TIPS, the presence of HVVC was associated with a reduced risk of overt HE and a potential survival benefit.

Feasibility and safety of ultrasound-guided percutaneous transhepatic measurement of portal venous pressure

BACKGROUND AND OBJECTIVE

The measurement of portal venous pressure (PVP) has been extensively studied, primarily through indirect methods. However, the potential of ultrasound-guided percutaneous transhepatic PVP measurement as a direct method has been largely unexplored. This study aimed to investigate the accuracy, safety, and feasibility of this approach.

METHODS

In vitro, the experiment aimed to select a needle that could accurately transmit pressure, had a small inner diameter and was suitable for liver puncture, and performed on 20 healthy New Zealand white rabbits. An ultrasound-guided percutaneous transhepatic portal vein puncture was undertaken to measure PVP. Additionally, free hepatic venous pressure (FHVP) and wedged hepatic venous pressure (WHVP) were measured under digital subtraction angiography (DSA). The correlation between the two methods was assessed. Enroll study participants from October 18, 2023 to November 11, 2023 with written informed consent. Five patients were measured the PVP under ultrasound guidance before surgery to determine the feasibility of this measurement method.

RESULTS

There was no significant difference in the results obtained using 9 different types of needles (P > 0.05). This demonstrated a great repeatability (P < 0.05). The 22G chiba needle with small inner diameter, allowing for accurate pressure transmission and suitable for liver puncture, was utilized for percutaneous transhepatic PVP measurement. There were positive correlations between PVP and HVPG (r = 0.881), PVP and WHVP (r = 0.709), HVPG and WHVP (r = 0.729), IVCP and FHVP (r = 0.572). The PVP was accurately and safely measured in 5 patients with segmental hepatectomy. No complications could be identified during postoperative ultrasound.

CONCLUSION

Percutaneous transhepatic portal venous puncture under ultrasound guidance is accurate, safe and feasible to measure portal venous pressure.

CLINICAL TRIAL REGISTRATION NUMBER

This study has been registered in the Chinese Clinical Trial Registry with registration number ChiCTR2300076751.

Variceal and Nonvariceal Upper Gastrointestinal Bleeding Refractory to Endoscopic Management: Indications and Role of Interventional Radiology

For over 60 years, diagnostic and interventional radiology have been heavily involved in the evaluation and treatment of patients presenting with gastrointestinal bleeding. For patients who present with upper GI bleeding and have a contraindication to endoscopy or have an unsuccessful attempt at endoscopy for identifying or controlling the bleeding, interventional radiology is often consulted for evaluation and consideration of catheter-based intervention.

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.

Hepatocellular Carcinoma with Hepatic Vein and Inferior Vena Cava Invasion

Hepatocellular carcinoma (HCC) invades intrahepatic vessels causing tumor thrombosis. Infrequently, there is involvement of the hepatic vein (HV) and inferior vena cava (IVC). In this review, we summarize the epidemiology, classification, clinical features, and management of HCC with HV and IVC invasion. While the involvement of HV and IVC usually portends an overall poor survival, selected patients may be candidates for aggressive treatment and thus improving outcomes.

Innovative angiography: a new approach to discover more hepatic vein collaterals in patients with cirrhotic portal hypertension

BACKGROUND

The hemodynamics of patients with cirrhosis and portal hypertension are complex and variable. We aimed to investigate differences in venous pressures determined by innovative angiography and conventional angiography using balloon occlusion of the hepatic veins in patients with alcoholic cirrhosis and portal hypertension.

METHODS

A total of 134 patients with alcoholic cirrhosis who fulfilled the inclusion criteria from June 2017 to June 2020 were included. During transjugular intrahepatic portosystemic shunt, conventional and innovative angiography were performed, and venous pressures were measured. A paired t-test and Pearson's correlation coefficient were used for analysis.

RESULTS

Conventional and innovative hepatic angiography detected lateral branches of the hepatic vein in 26 (19.4%) and 65 (48.5%) cases, respectively (P < 0.001). Innovative angiography detected a total of 65 patients with lateral shunts, of whom 37 (56.9%) had initial shunts. The average wedged hepatic venous pressure and portal venous pressure of the initial lateral branches were 21.27 ± 6.66 and 35.84 ± 7.86 mmHg, respectively, with correlation and determination coefficients of 0.342 (P < 0.05) and 0.117, respectively. The mean hepatic venous pressure gradient and portal pressure gradient were 9.59 ± 7.64 and 26.86 ± 6.78 mmHg, respectively, with correlation and determination coefficients of 0.292 (P = 0.079) and 0.085, respectively.

CONCLUSIONS

Innovative angiography reveals collateral branches of the hepatic veins more effectively than conventional angiography. Hepatic vein collateral branches are the primary factors leading to underestimation of wedged hepatic venous pressures and hepatic venous pressure gradients, with the initial hepatic vein collateral branches resulting in the most severe underestimations.

Agreement between Wedged Hepatic Venous Pressure and Portal Pressure in Hepatic Sinusoidal Obstruction Syndrome

Background: Wedge hepatic vein pressure (WHVP) accurately estimates the portal pressure (PP) in chronic sinusoidal portal hypertension patients. Whether this applies to patients with acute portal hypertension due to hepatic sinusoidal obstruction syndrome (HSOS) is unclear. Our aim was to assess the agreement between WHVP and PP in patients with HSOS by comparing them to decompensated cirrhosis patients. Methods: From December 2013 to December 2021, patients with pyrrolidine alkaloid-induced HSOS (PA-HSOS) receiving hepatic venous pressure gradient (HVPG) measurement and transjugular intrahepatic portosystem shunt (TIPS) were retrospectively collected and matched with those of patients with virus- or alcohol-related cirrhosis as a cirrhosis group. Pearson’s correlation (R), intraclass correlation coefficient (ICC), scatter plots, and the Bland−Altman method were performed for agreement evaluation. Results: A total of 64 patients were analyzed (30 PA-HSOS and 34 cirrhosis groups). The correlation between WHVP and PP was moderate in the PA-HSOS group (R: 0.58, p = 0.001; ICC: 0.68, p = 0.002) but good in the cirrhosis group (R: 0.81, p < 0.001; ICC: 0.90, p < 0.001). The percentage of patients with inconsistent WHVP and PP in the two groups was 13 (43.3%) and 15 (26.5%) (p = 0.156), respectively, and an overestimation of PP was more common in the PA-HSOS group (33.3% vs. 2.9%, p = 0.004). HVPG and portal pressure gradient (PPG) consistency was poor in both groups (R: 0.51 vs. 0.26; ICC: 0.65 vs. 0.41; p < 0.05). Conclusions: WHVP in patients with PA-HSOS did not estimate PP as accurately as in patients with virus- or alcohol-related cirrhosis, which was mainly due to PP overestimation.

Liver stiffness-based model predicts hepatic venous pressure gradient in patients with liver disease

BACKGROUND

The aim was to develop a model to predict clinically significant portal hypertension, hepatic venous pressure gradient (HVPG) ≥10 mmHg using pre-operative noninvasive makers.

METHODS

Patients who have been programmed for liver resection/transplantation were enrolled prospectively. Preoperative liver stiffness measurement (LSM), liver function test (LFT), and intraoperative HVPG were assessed. A probability score model to predict HVPG≥10 mmHg called HVPG₁₀ score was developed and validated.

RESULTS

A total of 161 patients [66% men, median age of 63 years] were recruited for the study. Median LSM, and HVPG were 9.5 kPa, and 5 mmHg respectively. HVPG₁₀ score was developed using independent predictors of HVPG≥10 mmHg in the training set were LSM, total bilirubin, alkaline phosphatase, and international normalized ratio. Area under receiver operating curve of HVPG₁₀ score in the training and validation sets were 0.91 and 0.93 respectively with a cutoff of 15. In the overall cohort, HVPG₁₀ score≥15 had 83% accuracy, 90% sensitivity, 81% specificity and 96% negative predictive value in predicting HVPG≥10 mmHg.

CONCLUSION

HVPG₁₀ score is an easy-to-use noninvasive continuous scale tool to rule out clinically significant portal hypertension in >95% patients with chronic liver disease.

Correlation of pressure gradient in three hepatic veins with portal pressure gradient

BACKGROUND

The liver is one of the most important organs in the human body, with functions such as detoxification, digestion, and blood coagulation. In terms of vascular anatomy, the liver is divided into the left and the right liver by the main portal vein, and there are three hepatic efferent veins (right, middle, and left) and two portal branches. Patients with impaired liver function have increased intrahepatic vascular resistance and splanchnic vasodilation, which may lead to an increase in the portal pressure gradient (PPG) and cause portal hypertension (PHT). In order to measure the increased pressure gradient of portal vein, the hepatic venous pressure gradient (HVPG) can be measured to reflect it in clinical practice. The accuracy of PPG measurements is directly related to patient prognosis.

AIM

To analyze the correlation between HVPG of three hepatic veins and PPG in patients with PHT.

METHODS

From January 2017 to December 2019, 102 patients with PHT who met the inclusion criteria were evaluated during the transjugular intrahepatic portosystemic shunt procedure and analyzed.

RESULTS

The mean HVPG of the middle hepatic vein was 17.47 ± 10.25 mmHg, and the mean HVPG of the right and left hepatic veins was 16.34 ± 7.60 and 16.52 ± 8.15 mmHg, respectively. The average PPG was 26.03 ± 9.24 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.15 and 0.02 (P = 0.164); 0.25 and 0.05 (P = 0.013); and 0.14 and 0.02 (P = 0.013), respectively. The mean wedged hepatic vein/venous pressure (WHVP) of the middle and left hepatic veins was similar at 29.71 ± 12.48 and 29.1 ± 10.91 mmHg, respectively, and the mean WHVP of the right hepatic vein was slightly lower at 28.01 ± 8.95 mmHg. The mean portal vein pressure was 34.11 ± 8.56 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.26 and 0.07 (P = 0.009); 0.38 and 0.15 (P < 0.001); and 0.26 and 0.07 (P = 0.008), respectively. The average free hepatic venous pressure (FHVP) of the right hepatic vein was lowest at 11.67 ± 5.34 mmHg, and the average FHVP of the middle and left hepatic veins was slightly higher at 12.19 ± 4.88 and 11.67 ± 5.34 mmHg, respectively. The average inferior vena cava pressure was 8.27 ± 4.04 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.30 and 0.09 (P = 0.002); 0.18 and 0.03 (P = 0.078); and 0.16 and 0.03 (P = 0.111), respectively.

CONCLUSION

Measurement of the middle hepatic vein HVPG could better represent PPG. Considering the high success rate of clinical measurement of the right hepatic vein, it can be the second choice.

Number of endoscopic sessions to eradicate varices identifies high risk of rebleeding in cirrhotic patients

BACKGROUND AND AIMS

Risk stratification to identify patients with high risk of variceal rebleeding is particularly important in patients with decompensated cirrhosis. In clinical practice, eliminating gastroesphageal varices thoroughly after sequential endoscopic treatment reduces the rebleeding rate, however, no simple method has been build to predict high risk of variceal rebleeding. We conducted this study to explore the value of the number of endoscopic sessions required to eradicate gastroesphageal varices in identifying high risk of rebleeding.

PATIENTS AND METHODS

Consecutive cirrhotic patients received sequential endoscopic therapy between January 2015 and March 2020 were enrolled. Endoscopic treatment was performed every 1-4 weeks until the eradication of varices. The primary endpoint was variceal rebleeding.

RESULTS

A total of 146 patients were included of which 60 patients received standard therapy and 86 patients underwent sequential endoscopic treatment alone. The cut-off value of the number of sequential endoscopic sessions is 3.5 times. Variceal rebleeding was significant higher in patients with endoscopic sessions > 3 times versus ≤ 3 times (61.5% vs. 17.5%, p < 0.001). Variceal rebleeding of patients with endoscopic sessions ≤ 3 times was significant lower than patients with > 3 times in group of standard therapy (19.6% vs. 88.9%, p < 0.001) and endoscopic therapy (15.9% vs. 47.1%, p = 0.028) respectively.

CONCLUSION

The number of sequential endoscopic sessions required to eradicate the varices is related to the risk of variceal rebleeding in patients with cirrhosis. If three times of endoscopic treatment can not eradicate the varices, a more aggressive treatment such as TIPS should be seriously considered.

Value of Liver Function Tests in Cirrhosis

The liver comprises both parenchymal and non-parenchymal cells with varying functions. Cirrhosis is often complicated by the development of portal hypertension and its associated complications. Hence, assessment of liver in cirrhosis should include assessment of its structural, function of both hepatic and non-hepatic tissue and haemodynamic assessment of portal hypertension. There is no single test that can evaluate all functions of liver and assess prevalence and severity of portal hypertension. Commonly available tests like serum bilirubin, liver enzymes (alanine [ALT] and aspartate aminotransferase [AST], serum alkaline phosphatase [ALP], gamma glutamyl transpeptidase [GGT]), serum albumin and prothrombin time for assessment of liver functions partly assess liver functions. quantitative liver functions like indocyanine clearance tests [ICG-K], methacetin breath test [MBT] were developed to assess dynamic status of liver but has its own limitation and availability. Imaging based assessment of liver by transient elastography, MRI based 99 mTc-coupled asialoglycoprotein mebrofenin scan help the clinician to assess liver function, functional volume of liver left after surgery and portal hypertension [PH]. Hepatic venous pressure gradient still remains the gold standard for the assessment of portal hypertension but is invasive and not available in all centres. Combinations of blood parameters in form of various indices like fibrosis score of 4 [FIB-4], Lok index, scores like model for end stage liver disease (MELD) and Child-Turcotte Pugh score are commonly used for assessing liver function in clinical practice.

Accurate reflection of hepatic venous pressure gradient by spleen stiffness measurement in patients with low controlled attenuation parameter values

Background and Aim

Spleen stiffness measurement (SSM) is useful for assessing portal hypertension. It is unclear whether SSM values are appropriate because vibration‐controlled transient elastography (VCTE) does not generate B‐mode images. This study aimed to confirm whether the controlled attenuation parameter (CAP) measured in the spleen can predict the accuracy of SSM.

Methods

This retrospective study enrolled 349 patients who underwent SSM using VCTE from January 2012 to December 2020. Consecutive patients were classified into the pilot set (SSM and hepatic venous pressure gradient [HVPG] were measured) and the validation set (SSM was measured without HVPG). In the pilot set, scatter plots with a nonparametric contour line were created. Logistic regression analysis was performed to predict outliers outside the 50% contour line.

Results

The values of CAP could distinguish the outliers in scatter plots between the HPVG and SSM in both univariate and multivariate analyses (cutoff, 118 dB/m). The correlation of SSM with HVPG (r = 0.718; P < 0.001) was significantly better in the low CAP (≤118 dB/m) group than in the high CAP (>118 dB/m) group (r = 0.330; P < 0.001). The area under the receiver operating characteristic curve of SSM in predicting high‐risk varices was better in the low CAP group than in all patients or in the high CAP group in the pilot set (0.881, 0.854, and 0.843, respectively) and in the validation set (0.893, 0.821, and 0.814, respectively).

Conclusion

For patients with CAP <118 dB/m, SSM is a feasible predictor of HVPG.

An Uncommon Cause of Biliary Obstruction in a Patient With Budd-Chiari Syndrome

Biliary varices (BVs) are an infrequent complication of chronic portal hypertension. Most cases of BVs are asymptomatic and are likely underdiagnosed. We present a case of a 34-year-old woman with Budd-Chiari syndrome who was found to have BVs caused by a significant inferior vena cava (IVC) stenosis. This case demonstrates that preprocedure imaging for variceal screening should be considered before biliary tract procedures to prevent complications.

The pharmacodynamic effect of terlipressin versus high-dose octreotide in reducing hepatic venous pressure gradient: a randomized controlled trial

Background

Vasoactive drugs can reduce portal venous pressure and control variceal bleeding. However, few studies have explored the hemodynamic effects of terlipressin and high-dose octreotide in such patients. Our purpose was to evaluate the hemodynamic changes and safety of using terlipressin and high-dose octreotide in patients with decompensated liver cirrhosis.

Methods

A multi-center randomized controlled trial was conducted. Cirrhotic patients with a history of variceal bleeding were included. Terlipressin or high-dose octreotide was administered during the procedure of measuring hepatic venous pressure gradient (HVPG). Hemodynamic parameters and symptoms were recorded.

Results

A total of 88 patients were included. HVPG was significantly reduced at 10, 20, and 30 min after drug administration in the terlipressin group (16.3±6.4 vs. 14.7±5.9, 14.0±6.1, and 13.8±6.1, respectively, P<0.001) and the high-dose octreotide group (17.4±6.6 vs. 15.1±5.8, 15.3±6.2, and 16.1±6.0, respectively P<0.01). Decreased heart rate and increased mean arterial pressure were more often observed in the terlipressin group. The overall response rates were not significantly different between the groups (52.8% vs. 44.8%, P=0.524). The terlipressin group had significantly higher response rates at 30 min compared to the high-dose octreotide group in those with alcoholic liver cirrhosis [6/6 (100%) vs. 0/4 (0%), P=0.005]. The incidence of adverse drug events was rare and similar in the two groups.

Conclusions

Both terlipressin and high-dose octreotide were effective and safe for reducing HVPG. The pharmacodynamic effect of terlipressin persisted longer. The terlipressin group had higher response rates in those with alcoholic cirrhosis (trial number: NCT02119884).

Degree of Portal and Systemic Hemodynamic Alterations Predict Recurrent AKI and Chronic Kidney Disease in Patients With Cirrhosis

The relevance of hemodynamic derangements on the incidence of recurrent acute kidney injury (AKI) and chronic kidney disease (CKD) in patients with cirrhosis is largely unknown. Consecutive patients with cirrhosis with a complete record of baseline hemodynamics were followed for identifying risk factors for the development of recurrent AKI and CKD by using negative binomial regression and competing risk analysis, respectively. Consecutive patients with cirrhosis (n = 2013, age 50.1 ± 11.8 years, 80% male, Child A:B:C percentage 13.7:52.9:33.4, and mean Child-Turcotte-Pugh score 8.6 ± 1.8) were enrolled, 893 (44.3%) of whom received beta-blockers, with 44.2% responders. Prior AKI was noted in 12.4% at enrollment. At a median follow-up of 379 (interquartile range: 68-869) days, AKI developed at a rate of 0.37 episodes per person-year, and 26% patients developed CKD. A lower mean number of AKI episodes (0.05 ± 0.25 vs. 0.42 ± 0.868; P < 0.001), CKD (subdistribution hazard ratio 0.74 [0.54-1.02]), and mortality (hazard ratio 0.21 [0.06-0.73]) were observed in beta-blocker responders. Albuminuria was an independent risk factor for recurrent AKI, CKD, and mortality (P < 0.05). Lower systemic vascular resistance index predicted hemodynamic response (odds ratio 2.04 [1.29-3.22]), cumulative AKI episodes (ratio of means 0.10 [0.08-0.14]), and development of CKD (subdistribution hazard ratio 0.70 [0.58-0.83]). Higher hepatic venous pressure gradient (≥17 mm Hg) predicted AKI episodes (ratio of means 1.76 [1.32-2.35]) but not CKD. Conclusion: High portal pressure and severe vasodilatation predispose patients with cirrhosis to repeated AKI episodes and development of CKD. Response to beta-blockers and therapies targeting the vasodilatory state could prevent frequent AKI and the risk of CKD development. Albuminuria could serve as an early marker of renal dysfunction in patients with cirrhosis.

Impact of Intrahepatic Venovenous Shunt on Hepatic Venous Pressure Gradient Measurement

PURPOSE

To quantitatively analyze the impact of intrahepatic venovenous shunt (IHVS) on hepatic venous pressure gradient (HVPG) measurement.

MATERIALS AND METHODS

From 2015 to 2019, 222 HVPG measurements performed during transjugular intrahepatic portosystemic shunt creation were eligible for this study. Digital subtraction angiography (DSA) software color-coded each pixel of a two-dimensional DSA series by time-intensity curve to classify IHVS. Different degrees of IHVS were found in 36.5% of patients (81/222). Mild IHVS was found in 10.8% of patients (24/222), moderate IHVS was found in 10.8% of patients (24/222), and severe IVHS was found in 14.9% of patients (33/222).

RESULTS

Mean wedged hepatic vein pressure (WHVP) and HVPG were significantly lower in patients with IHVS compared with patients without IHVS (WHVP: 17.78 mm Hg ± 7.00 vs 24.89 mm Hg ± 8.69, P = .001; HVPG: 11.93 mm Hg ± 5.76 vs 18.6 mm Hg ± 6.85, P < .001). Mild IHVS had little effect on WHVP and HVPG. Mean WHVP and HVPG were 11 mm Hg lower in patients with moderate IHVS (WHVP: 20.38 mm Hg ± 8.38 vs 31.5 mm Hg ± 9.39, P = .026; HVPG: 13.88 mm Hg ± 6.33 vs 25.00 mm Hg ± 9.81, P < .001) and 15 mm Hg lower in patients with severe IHVS (WHVP: 13.45 mm Hg ± 5.28 vs 28.64 mm Hg ± 6.38, P = .017; HVPG: 8.27 mm Hg ± 3.85 vs 23.45 mm Hg ± 6.95, P < .001) than mean portal vein pressure and portal vein gradient.

CONCLUSIONS

For patients with moderate or severe IHVS, HVPG might greatly underestimate the actual value of portal vein pressure, and the portal vein should be catheterized to measure portal pressure.

Intrahepatic veno-venous collateralization and misrepresentative hepatic venous pressure gradients in children

BACKGROUND

Accurate and reproducible means of measuring the portosystemic gradient are essential for risk stratification and treatment of portal hypertension.

OBJECTIVE

To report the reliability of hepatic venous pressure gradients in children with intrahepatic veno-venous collateralization.

MATERIALS AND METHODS

Between January 2012 and December 2019 (96 months), 39 patients with native livers underwent wedge hepatic venography and hepatic venous pressure gradient measurements at a tertiary pediatric center. All archived images were reviewed for balloon isolation of the hepatic vein and hepatic vein-to-hepatic vein (HV-HV) collaterals. HV-HV collaterals were categorized as present on the basis of non-catheterized segmental venous opacification despite appropriate balloon isolation. Hepatic venous pressure gradient was defined as the difference of wedge and free hepatic venous pressures. Wedge portosystemic gradient was defined as the difference between wedge hepatic venous pressure and right atrial (RA) pressures. For patients subsequently undergoing portal venous catheterization, portosystemic gradient was defined as the difference between main portal vein and RA pressures.

RESULTS

Thirteen of 39 (33.3%) patients demonstrated HV-HV collaterals on wedge hepatic venography. The mean hepatic venous pressure gradient was 5.2±3.8 mmHg (range: 0-15 mmHg). The mean hepatic venous pressure gradient was 3.6±2.6 mmHg (range: 0-9 mmHg) in the presence of HV-HV collaterals and 5.9±4.2 mmHg (range: 1-15 mmHg) in the absence of HV-HV collaterals (P=0.043). Twelve (30.8%) patients were found to have varices: 10 gastroesophageal, 1 rectal and 1 stomal. The mean hepatic venous pressure gradient in patients with varices was 5.4±47 mmHg (range: 0-15 mmHg). For patients with varices, mean hepatic venous pressure gradient was 3.0±2.7 mmHg (range: 0-9 mmHg) in the presence of HV-HV collaterals and 10.3±4.1 mmHg (range: 5-15 mmHg) in the absence of HV-HV collaterals (P=0.004). Four (10.3%) patients had extrahepatic portal vein occlusion: 3 with cavernous transformation and 1 with type Ib Abernethy malformation. All patients with extrahepatic portal vein occlusion demonstrated HV-HV collaterals compared with 8 of 35 (22.9%) patients without extrahepatic portal vein occlusion (P=0.002). Four of 39 (10.3%) patients underwent direct portal pressure measurements: 3 via transhepatic and 1 via trans-splenic portal access. All had demonstrated HV-HV collaterals on wedged imaging. One had extrahepatic portal vein occlusion. The mean time between wedge portosystemic gradient and portosystemic gradient measurement was 3.75 days (range: 0-8 days). The mean wedge portosystemic gradient was 4.5±3.1 mmHg (range: 2-9 mmHg) and the mean portosystemic gradient was 14.5±3.7 mmHg (range: 12-20 mmHg) (P=0.006).

CONCLUSION

HV-HV collateralization is frequently observed in children undergoing wedged portal venography and leads to misrepresentative hepatic venous pressure gradients. All patients undergoing hepatic venous pressure gradient measurement should have wedged venography to identify HV-HV collaterals and to qualify measured pressures. Additional techniques to obtain representative pressures in the presence of HV-HV collaterals warrant further investigation.

A computational model-based study on the exchangeability of hepatic venous pressure gradients measured in multiple hepatic veins

Hepatic venous pressure gradient (HVPG) is a hemodynamic index widely used for evaluating the severity of portal hypertension. Theoretically, HVPG can be measured in any of the three major (i.e., right, middle and left) hepatic veins (HVs); however, it remains unclear whether HVPGs measured in different HVs are exchangeable, and if not, what factors cause inter-HV HVPG differences? In consideration of the potential limitations of invasive in vivo measurements, we employed a computational model implemented in conjunction with stochastic parameter sampling to simulate and compare HVPG measurements in multiple HVs under various sinusoidal portal hypertensive conditions. Results demonstrated that HVPGs measured in the right and middle HVs were basically exchangeable, whereas those in the left HV were relatively lower due primarily to the smaller proportion of hepatic venous flow through the left HV compared with that through the right or middle HV. Moreover, it was found that hepatic vein-to-vein shunts (HVVS) led to a marked augmentation of inter-HV HVPG differences and significant underestimation of portal pressure gradient with HVPG. These findings suggest that understanding the distribution of hepatic venous flow and status of HVVS is essential for selecting a proper HV for implementing HVPG measurement in clinical practice.

Predictors of Occurrence and Risk of Hepatic Encephalopathy After TIPS Creation: A 15-Year Experience

PURPOSE

To identify clinical variables, including use of newer Viatorr TIPS endoprosthesis with controlled expansion (VCX) that may affect the occurrence and risk of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt (TIPS) creation.

METHODS

A total of 376 patients who underwent TIPS creation at our institution between 2003 and 2018 were retrospectively identified. Of these patients, 71 received a Viatorr controlled expansion endoprosthesis and 305 received a Viatorr TIPS endoprosthesis (older version without controlled expansion). Multivariate regression analysis was used to identify factors predicting the occurrence of hepatic encephalopathy after TIPS creation; a Cox proportional hazard model was used to assess risk of HE through time to HE onset RESULTS: A total of 194 patients (52%) developed hepatic encephalopathy after TIPS creation, including 28 of 71 patients (39%) who received a VCX endoprosthesis. Older patient age and the use of Viatorr endoprosthesis without controlled expansion were significantly associated with the development of hepatic encephalopathy overall. Pre-TIPS pressure variables, patient age, plasma international normalized ratio, and model for end-stage liver disease score were risk factors for time to hepatic encephalopathy.

CONCLUSION

Several variables are mild predictors of early hepatic encephalopathy development after TIPS creation, and the use of VCX endoprosthesis in TIPS creation is associated with a modest lower risk of hepatic encephalopathy. These preliminary findings should be considered in regard to patient selection, endoprosthesis selection, and post-transjugular intrahepatic portosystemic shunt creation monitoring for the development of hepatic encephalopathy.

The New Cutoff Value of the Hepatic Venous Pressure Gradient on Predicting Long-Term Survival in Cirrhotic Patients

BACKGROUND

This study aimed to determine the prognostic role of the categorized hemodynamic stage (HS) based on the hepatic venous pressure gradient (HVPG) in patients with portal hypertension.

METHODS

Of 1,025 cirrhotic patients who underwent HVPG measurement, data on 572 non-critically-ill patients were collected retrospectively between 2008 and 2013. The following two HS categorizations were used: HS-1 (6-9, 10-12, 13-16, 17-20, and > 20 mmHg; designated as groups 1-5, respectively) and HS-2 (6-12, 13-20, and > 20 mmHg). Clinical characteristics, mortality rates, and prognostic predictors were analyzed according to the categorized HS.

RESULTS

During the mean follow-up period of 25 months, 86 (15.0%) patients died. The numbers of deaths in HS-1 groups were 7 (6.3%), 7 (6.9%), 30 (18.0%), 20 (15.6%), and 22 (34.4%), respectively (P < 0.001). However, the traditional HVPG cutoffs of 10 and 16 mmHg did not improve the discrimination of mortality. In contrast, the mortality rates did differ significantly between the three HS-2 groups (P < 0.05). In the multivariate analysis, all models revealed that HS-2 was a common prognostic factor in predicting mortality. The mortality rates increased significantly according to HS-2 in patients with hypoalbuminemia (HVPG, 13-20 mmHg; hazard ratio [HR], 2.54 and HVPG > 20 mmHg; HR, 5.45) and intermediate model for end-stage liver disease (MELD) score (HVPG, 13-20 mmHg; HR, 3.86 and HVPG > 20 mmHg; HR, 8.77; P < 0.05).

CONCLUSION

Categorizing HVPG values according to HS-2 is a useful prognostic modality in patients with portal hypertension and can play an independent role in predicting the prognosis in patients with hypoalbuminemia and an intermediate MELD score.

Noninvasive Evaluation of Portal Hypertension Using a Supervised Learning Technique

Portal hypertension (PHT) is a key event in the evolution of different chronic liver diseases and leads to the morbidity and mortality of patients. The traditional reliable PHT evaluation method is a hepatic venous pressure gradient (HVPG) measurement, which is invasive and not always available or acceptable to patients. The HVPG measurement is relatively expensive and depends on the experience of the physician. There are many potential noninvasive methods to predict PHT, of which liver transient elastography is determined to be the most accurate; however, even transient elastography lacks the accuracy to be a perfect noninvasive diagnostic method of PHT. In this research, we are focusing on noninvasive PHT assessment methods that rely on selected best-supervised learning algorithms which use a wide set of noninvasively obtained data, including demographical, clinical, laboratory, instrumental, and transient elastography measurements. In order to build the best performing classification meta-algorithm, a set of 21 classification algorithms have been tested. The problem was expanded by selecting the best performing clinical attributes using algorithm-specific filtering methods that give the lowest error rate to predict clinically significant PHT. The suggested meta-algorithm objectively outperforms other methods found in literature and can be a good substitute for invasive PHT evaluation methods.

The impact of esophagogastric varices on the prognosis of patients with hepatocellular carcinoma

Whether or not esophagogastric varices (EGV) could determine the outcomes of patients with hepatocellular carcinoma (HCC) is still unclear. A total of 990 treatment-naive HCC patients who received an esophagogastroduodenoscopy at the time of HCC diagnosis were retrospectively enrolled. The factors in terms of prognosis were analyzed by Cox proportional hazards model and propensity score matching analysis. Among the enrolled patients, 480 (48.5%) patients had EGV. Patients with EGV had a significantly lower cumulative 5-year survival rate than those without EGV (24.9% versus 46.4%, p < 0.001). It was confirmed by a multivariate analysis and propensity score matching analysis. Stratified by tumor stage, the patients with EGV had lower survival rates than the patients without EGVs in all Barcelona Clinic Liver Cancer stages except stage D. Moreover, the patients with EGV had lower survival rates than those without EGV, both by curative or non-curative treatment modalities. In conclusion, EGV was an independent risk factor predicting poor prognosis for the patients with HCC by multivariate analysis, propensity score matching analysis, and subgroup analysis.

Ultrasound elastography: liver

Ultrasound elastography, also termed sonoelastography, is being used increasingly in clinical practice to aid the diagnosis and management of diffuse liver disease. Elastography has been shown to be capable of differentiating advanced and early-stage liver fibrosis, and consequently a major application in clinical liver care includes progression to cirrhosis risk stratification through (1) assessment of liver fibrosis stage in HCV and HBV patients, (2) distinguishing non-alcoholic steatohepatitis from simple steatosis in non-alcoholic fatty liver disease patients, and (3) prognostic evaluation of liver disease is autoimmune liver disease. In addition, elastographic characterization of focal liver lesions and evaluation of clinically significant portal hypertension have the potential to be clinically useful and are areas of active clinical research.

Intrahepatic portal vein blood volume estimated by non-contrast magnetic resonance imaging for the assessment of portal hypertension

PURPOSE

To investigate the feasibility of estimating the portal vein blood volume that flows into the intrahepatic volume (IHPVBV) in each cardiac cycle using non-contrast MR venography technique as a surrogate marker of portal hypertension (PH).

MATERIALS AND METHODS

Ten patients with chronic liver disease and clinical symptoms of PH (40% males, median age: 54.0, range: 44-73 years old) and ten healthy volunteers (80% males, median age: 54.0, range: 44-66 years old) were included in this study. A non-contrast Triple-Inversion-Recovery Arterial-Spin-Labeling (TIR-ASL) technique was used to quantify the IHPVBV in one and two cardiac cycles. Liver (LV) and spleen volumes (SV) were measured by manual segmentation from anatomical MR images as morphological markers of PH. All images were acquired in a 1.5T Philips Achieva MR scanner.

RESULTS

PH patients had larger SV (P=0.02) and lower liver-to-spleen ratio (P=0.02) compared with healthy volunteers. The median IHPVBV in healthy volunteers was 13.5cm(3) and 26.5cm(3) for one and two cardiac cycles respectively, whereas in PH patients a median volume of 3.1cm(3) and 9.0cm(3) was observed. When correcting by LV, the IHPVBV was significantly higher in healthy volunteers than PH patients for one and two cardiac cycles. The combination of morphological information (liver-to-spleen ratio) and functional information (IHPVBV/LV) can accurately identify the PH patients with a sensitivity of 90% and specificity of 100%.

CONCLUSION

Results show that the portal vein blood volume that flows into the intrahepatic volume in one and two cardiac cycles is significantly lower in PH patients than in healthy volunteers and can be quantified with non-contrast MRI techniques.

Portal flow modulation in auxiliary partial orthotopic liver transplantation

APOLT is a suitable technique of liver transplantation in patients with ALF and some types of MLD. Portal venous steal is a problem with this procedure that leads to graft dysfunction and failure. Modulation of the portal flow to the graft and native liver can help in preventing this problem. We discuss the pathophysiology of this complication, review available literature regarding its management, and describe our results using the technique of graded hemiportal banding to achieve adequate perfusion for the graft and native liver.

Staging of liver fibrosis or cirrhosis: The role of hepatic venous pressure gradient measurement

Liver fibrosis is a common histological change of chronic liver injury and it is closely related with portal hypertension which is hemodynamic complication of chronic liver disease. Currently, liver fibrosis has been known as a reversible dynamic process in previous literatures. Although liver biopsy is a gold standard for assessing the stage of liver fibrosis, it may not completely represent the stage of liver fibrosis because of sampling error or semi-quantative measurement. Recent evidences suggested that histologic, clinical, hemodynamic, and biologic features are closely associated in patients with chronic liver disease. Hepatic venous pressure gradient (HVPG) measurement has been known as a modality to evaluate the portal pressure. The HVPG measurement has been used clinically for fibrosis diagnosis, risk stratification, preoperative screening for liver resection, monitoring the efficacy of medical treatments, and assessing the prognosis of liver fibrosis. Therefore, the HVPG measurement can be used to monitor areas the chronic liver disease but also other important areas of chronic liver disease.

Baseline and serial liver stiffness measurement in prediction of portal hypertension progression for patients with compensated cirrhosis

BACKGROUND & AIMS

Liver stiffness measurement (LSM) using transient elastography is useful in prediction of significant portal hypertension (PHT). To evaluate the usefulness of baseline and serial LSM in predicting clinical disease progression (CDP) for patients with compensated hepatic cirrhosis.

METHODS

Consecutive patients with compensated cirrhosis and without hepatocellular carcinoma (HCC) were prospectively enrolled. Baseline LSM was assessed at enrolment, then at a 6- to 12-month interval. Esophagogastroduodenoscopy and ultrasonography were performed regularly for surveillance of varices and HCC, while CDP including HCC development and PHT progression was recorded.

RESULTS

Two hundred and twenty patients were enrolled. In a median follow-up of 36.9 months, CDP were detected in 49 patients including 30 PHT progression and 19 HCC developments. The cumulative incidence of CDP, PHT progression and HCC development at 3 years was 20.7%, 12.8% and 9.1% respectively. Multivariate analyses showed that baseline LSM was an independent predictor of PHT progression and CDP, however, not of HCC occurrence. The performance of baseline LSM in predicting PHT progression, varices growth/development and hepatic decompensation was 0.744, 0.638 and 0.929. With 17, 12 and 21.1 kPa as the cut-off, the negative predictive value was 92, 94 and 99% respectively. Patients with baseline LSM ≧17 kPa without serial changes had higher risk of PHT progression.

CONCLUSION

For patients with compensated cirrhosis, LSM was an independent predictor of PHT progression and CDP, but not of HCC occurrence. Baseline LSM was useful to exclude PHT progression. Patients with baseline and serial LSM ≧17 kPa had higher risk of PHT progression.

Implication of microscopic and macroscopic vascular invasion for liver resection in patients with hepatocellular carcinoma

BACKGROUND AND AIM

Long-term data after liver resection for hepatocellular carcinoma (HCC) with vascular invasion are rare for non-Asian patients. The aim of the present study was to analyze the long-term outcome of liver resection for HCC with vascular invasion and to compare the results of subgroups with micro- and macrovascular invasion.

METHODS

From January 2000 to September 2010, 288 patients without extrahepatic metastases underwent liver resection for HCC. In 107 out of 288 patients (37%), vascular invasion was found in the final pathological analysis. The long-term outcome as well as the perioperative course of these patients was analyzed using a prospective database.

RESULTS

The 1-, 3- and 5-year cumulative survival rate of HCC patients with vascular invasion was 64.3, 41.4 and 23.9%, respectively. The median survival was 19 months. In the multivariate analysis, the overall survival was not influenced by the type of vascular invasion (micro- vs. macrovascular invasion), however overall survival was significantly impaired in case of lymphatic vessel invasion, intraoperative blood transfusions, need of fresh frozen plasma application, prolonged ICU stay and elevated preoperative bilirubin levels.

CONCLUSIONS

Acceptable survival rates can be achieved in selected patients with macrovascular invasion after surgical resection, which is not markedly different from those with microvascular invasion. In view of an otherwise poor prognosis, liver resection seems to be justified for selected HCC patients with macrovascular invasion, although this stands in contrast with the BCLC recommendations. However, it is in accordance for example with the guidelines of the Asia-Pacific Association for the Study of the Liver.

Peculiar characteristics of portal-hepatic hemodynamics of alcoholic cirrhosis

Alcohol-related cirrhosis is a consequence of heavy and prolonged drinking. Similarly to patients with cirrhosis of other etiologies, patients with alcoholic cirrhosis develop portal hypertension and the hepatic, splanchnic and systemic hemodynamic alterations that follow. However, in alcoholic cirrhosis, some specific features can be observed. Compared to viral cirrhosis, in alcohol-related cirrhosis sinusoidal pressure is generally higher, hepatic venous pressure gradient reflects portal pressure better, the portal flow perfusing the liver is reduced despite an increase in liver weight, the prevalence of reversal portal blood flow is higher, a patent paraumbilical vein is a more common finding and signs of hyperdynamic circulations, such as an increased cardiac output and decreased systemic vascular resistance, are more pronounced. Moreover, alcohol consumption can acutely increase portal pressure and portal-collateral blood flow. Alcoholic cardiomyopathy, another pathological consequence of prolonged alcohol misuse, may contribute to the hemodynamic changes occurring in alcohol-related cirrhosis. The aim of this review was to assess the portal-hepatic changes that occur in alcohol-related cirrhosis, focusing on the differences observed in comparison with patients with viral cirrhosis. The knowledge of the specific characteristics of this pathological condition can be helpful in the management of portal hypertension and its complications in patients with alcohol-related cirrhosis.

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Hepatic venous pressure gradient: clinical use in chronic liver disease

Portal hypertension is a severe consequence of chronic liver diseases and is responsible for the main clinical complications of liver cirrhosis. Hepatic venous pressure gradient (HVPG) measurement is the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >10 mmHg. In this condition, the complications of portal hypertension might begin to appear. HVPG measurement is increasingly used in the clinical fields, and the HVPG is a robust surrogate marker in many clinical applications such as diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who had a reduction in HVPG of ≥ 20% or to ≤ 12 mmHg in response to drug therapy are defined as responders. Responders have a markedly decreased risk of bleeding/rebleeding, ascites, and spontaneous bacterial peritonitis, which results in improved survival. This review provides clinical use of HVPG measurement in the field of liver disease.

Hepatic venous pressure gradient: clinical use in chronic liver disease

Portal hypertension is a severe consequence of chronic liver diseases and is responsible for the main clinical complications of liver cirrhosis. Hepatic venous pressure gradient (HVPG) measurement is the best available method to evaluate the presence and severity of portal hypertension. Clinically significant portal hypertension is defined as an increase in HVPG to >10 mmHg. In this condition, the complications of portal hypertension might begin to appear. HVPG measurement is increasingly used in the clinical fields, and the HVPG is a robust surrogate marker in many clinical applications such as diagnosis, risk stratification, identification of patients with hepatocellular carcinoma who are candidates for liver resection, monitoring of the efficacy of medical treatment, and assessment of progression of portal hypertension. Patients who had a reduction in HVPG of ≥ 20% or to ≤ 12 mmHg in response to drug therapy are defined as responders. Responders have a markedly decreased risk of bleeding/rebleeding, ascites, and spontaneous bacterial peritonitis, which results in improved survival. This review provides clinical use of HVPG measurement in the field of liver disease.

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.

Hepatic venous pressure measurements: comparison of end-hole and balloon catheter methods

PURPOSE

To determine the difference in hepatic venous pressures measured with the use of an end-hole diagnostic catheter versus a balloon catheter.

MATERIALS AND METHODS

A total of 92 patients underwent transjugular hepatic venous pressure measurements with a 5-F diagnostic end-hole catheter and a balloon catheter, with the catheter type used initially determined randomly. With both catheters, free and wedged systolic, diastolic, and mean pressures were collected. Hepatic venous pressure gradients were calculated from each pressure set. Eighty-five patients (92%) also underwent concurrent transjugular biopsy after pressures were recorded. Demographic, histologic, and specific procedural information were also collected.

RESULTS

The study included 47 men and 45 women, with a mean age of 52.7 years (range, 19-84 y). For the entire population, there were statistically significant differences in mean measurements between the two catheters in wedged systolic (P = .004), diastolic (P = .021), and mean (P = .036) pressures. However, the differences between the means were only 0.783, 0.609, and 0.207 mm Hg, respectively. A subanalysis based on histologic stage revealed no difference between catheter types for normal or cirrhotic livers, but a significant (P = .017) difference in systolic wedged pressure (absolute difference of 0.67 mm Hg) in patients with mild to moderate fibrosis (stages 1-3). In all differences, the balloon catheter had the greater pressure reading.

CONCLUSIONS

There was a significant difference in wedged pressure measurements between the two catheter systems in the overall population and among patients with a histologic grade indicating fibrosis. However, the absolute value differences between the two systems were comparatively small (< 1 mm Hg).

The impact of hepatic pressurization on liver shear wave speed estimates in constrained versus unconstrained conditions

Increased hepatic venous pressure can be observed in patients with advanced liver disease and congestive heart failure. This elevated portal pressure also leads to variation in acoustic radiation-force-derived shear wave-based liver stiffness estimates. These changes in stiffness metrics with hepatic interstitial pressure may confound stiffness-based predictions of liver fibrosis stage. The underlying mechanism for this observed stiffening behavior with pressurization is not well understood and is not explained with commonly used linear elastic mechanical models. An experiment was designed to determine whether the stiffness increase exhibited with hepatic pressurization results from a strain-dependent hyperelastic behavior. Six excised canine livers were subjected to variations in interstitial pressure through cannulation of the portal vein and closure of the hepatic artery and hepatic vein under constrained conditions (in which the liver was not free to expand) and unconstrained conditions. Radiation-force-derived shear wave speed estimates were obtained and correlated with pressure. Estimates of hepatic shear stiffness increased with changes in interstitial pressure over a physiologically relevant range of pressures (0-35 mmHg) from 1.5 to 3.5 m s(-1). These increases were observed only under conditions in which the liver was free to expand while pressurized. This behavior is consistent with hyperelastic nonlinear material models that could be used in the future to explore methods for estimating hepatic interstitial pressure noninvasively.