Assessing portal hypertension in liver diseases

Clinical Assessment and Management of Portal Hypertension

The development of portal hypertension in a patient with cirrhosis portends a poor prognosis. Untreated or progressive portal hypertension has serious clinical outcomes, which are often fatal. It is important to recognize portal hypertension early to delay progression and to treat complications of portal hypertension as they arise. This review will focus on the clinical assessment and management of portal hypertension.

Considerations for bariatric surgery in patients with cirrhosis

With the ever increasing global obesity pandemic, clinical burden from obesity related complications are anticipated in parallel. Bariatric surgery, a treatment approved for weight loss in morbidly obese patients, has reported to be associated with good outcomes, such as reversal of type two diabetes mellitus and reducing all-cause mortality on a long term basis. However, complications from bariatric surgery have similarly been reported. In particular, with the onslaught of non-alcoholic fatty liver disease (NAFLD) epidemic, in associated with obesity and metabolic syndrome, there is increasing prevalence of NAFLD related liver cirrhosis, which potentially connotes more risk of specific complications for surgery. Bariatric surgeons may encounter, either expectedly or unexpectedly, patients with non-alcoholic steatohepatitis (NASH) and NASH related cirrhosis more frequently. As such, the issues and considerations surrounding their medical care/surgery warrant careful deliberation to ensure the best outcomes. These considerations include severity of cirrhosis, liver synthetic function, portal hypertension and the impact of surgical factors. This review explores these considerations comprehensively and emphasizes the best approach to managing cirrhotic patients in the context of bariatric surgery.

Identification of miRNAs associated with the mechanical response of hepatic stellate cells by miRNA microarray analysis

It has been suggested that hepatic stellate cells (HSCs) could be used in the regulation of liver microcirculation and portal hypertension. The effects of tensile strain on the microRNA (miRNA) profile of HSCs are largely unknown. In this study, we aimed to explore the changes of miRNA expression in tensile strain-treated HSCs. The purity and activation of HSCs were determined by immunofluorescence staining with antibody against desmin and a-SMA, respectively. miRNA profile analysis was performed on HSCs with and without tensile strain treatment (n=3) using microarray analysis. We identified 6 significantly differentially expressed miRNAs (DEMs), including 1 downregulated (rno-miR-125b-2-3p) and 5 upregulated (rno-miR-1224, rho-miR-188-5p, rho-miR-211-3p, rho-miR-3584-5p and rho-miR-466b-5p), which were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) experiments. Further analysis of the DEMs revealed that many important biological processes and signal pathways were triggered in tensile strain-treated HSCs. These include the signal transduction mechanisms associated with protein binding, apoptosis, proliferation, and the FoxO and Wnt signaling pathways. In conclusion, this study presents the specific DEMs in tensile strain-treated HSCs. Our study provide novel miRNA-based information that may enhance our understanding of the pathophysiological processes leading to portal hypertension.

Doppler assessment of children with liver cirrhosis and portal hypertension in comparison with a healthy control group: An analytical cross-sectional study

Background:

Doppler ultrasonography (Doppler US) plays an important role in evaluating patients with liver cirrhosis. This study aims to investigate the hemodynamic alterations of hepatic artery and portal vein among children with liver cirrhosis and portal hypertension (esophageal varices).

Materials and Methods:

We conducted an analytical cross-sectional study in Imam Hossein Children's Hospital, Isfahan, Iran, in 2016. A number of 33 cirrhotic children with or without esophageal varices were selected through convenience sampling method to be compared with 19 healthy children as controls using color and spectral Doppler US.

Results:

Portal vein mean velocities were 15.03 ± 7.3 cm/s in cirrhotics, 16.47 ± 6.4 cm/s in controls (P = 0.51), 11.6 ± 4.7 cm/s in patients with varices, and 17.9 ± 7.3 cm/s in patients without varices (P = 0.015). Mean diameters of caudate lobe, portal vein, and splenic vein, as well as the mean values of liver and spleen span, were significantly higher in cirrhotic children. The frequency of flow reversal (hepatofugal flow) was not detected significantly different in cirrhotics. Peak systolic velocity, end diastolic velocity, pulsatility index, and resistive index for hepatic artery as well as liver vascular index were not significantly different in cirrhotics in comparison with controls.

Conclusion:

Alterations in Doppler parameters of portal vein including diameter and velocity may be the helpful indicators of liver cirrhosis and esophageal varices in children, respectively. Parameters of hepatic artery may not differentiate children with liver cirrhosis.

Noninvasive Assessment of Portal Hypertension in Advanced Chronic Liver Disease: An Update

The assessment of portal hypertension is a relevant step in the evaluation of newly diagnosed advanced chronic liver disease (ACLD). The current gold standard includes the invasive evaluation of hepatic venous pressure gradient (HVPG) and endoscopy. However, noninvasive or minimally invasive techniques to assess portal hypertension have been proposed and well established. In the present manuscript, we review clinical studies on the use of noninvasive or minimally invasive techniques to assess portal hypertension in ACLD patients.

Metabolomics: From liver chiromancy to personalized precision medicine in advanced chronic liver disease

Currently there is a lack of accurate biomarkers for diagnosis and prognosis in advanced liver diseases. Either the occurrence of first decompensation, or diagnosis of acute on chronic liver failure, severe alcoholic hepatitis, or hepatocellular carcinoma (HCC), none of the available biomarkers are satisfactory. Metabolomics is the newest of omics, being much closer than the others to the actual phenotype and pathologic changes that characterizes a certain condition. It deals with a much wider spectrum of low molecular weight bio-compounds providing a powerful platform for discovering novel biomarkers and biochemical pathways to improve diagnostic, prognostication and therapy. Until now metabolomics was applied in a wide spectrum of liver conditions, but the findings were contradictory. This review proposes a synthesis of the existing evidences of metabolomics use in advanced chronic liver diseases, decompensated liver cirrhosis, severe alcoholic hepatitis and HCC.

Evaluation of portal pressure by doppler ultrasound in patients with cirrhosis before and after simvastatin administration - a randomized controlled trial

Background: Portal hypertension is one of the most frequent complications of cirrhosis. β-adrenergic blockers, with or without organic nitrates, are currently used as hypotensive agents. Statins such as simvastatin seem to be safe for patients with chronic liver diseases and exert multiple pleiotropic actions. This study aimed to assess PTH using Doppler ultrasound in patients with cirrhosis before and after simvastatin administration.

Methods: This randomized controlled clinical trial was conducted on 40 patients with cirrhosis who were randomized into 2 groups: group I included 20 patients with cirrhosis who were administered 20 mg of simvastatin daily for 2 weeks and then 40 mg daily for another 2 weeks, and group II included 20 patients with cirrhosis who did not receive simvastatin as a control group. All patients underwent full clinical examination, laboratory investigations, and abdominal Doppler ultrasound at baseline and after 30 days to evaluate portal vein diameter, blood flow volume, direction and velocity of portal vein blood flow, hepatic artery resistance and pulsatility indices, splenic artery resistance index, portal hypertension index (PHI), liver vascular index, and modified liver vascular index (MLVI).

Results: There was a highly significant decrease in the hepatic artery resistance index  in group I, from 0.785 ± 0.088 to 0.717 ± 0.086 (P < 0.001). There was a significant decrease in the PHI in group I , from 3.915 ± 0.973 m/sec to 3.605 ± 1.168 m/sec (P = 0.024). Additionally, there was a significant increase in the MLVI in group I from 11.540 ± 3.266 cm/sec to 13.305 ± 3.222 cm/sec, an increase of 15.3% from baseline (P = 0.009). No significant adverse effects were detected.

Conclusions: Simvastatin is safe and effective in lowering portal hypertension.

[ClinicalTrials.gov Identifier: NCT02994485]

Elastography methods for the non-invasive assessment of portal hypertension

The gold standard to assess the presence and severity of portal hypertension remains the hepatic vein pressure gradient, however the recent development of non-invasive assessment using elastography techniques offers valuable alternatives. In this review, we discuss the diagnostic accuracy and utility of such techniques in patients with portal hypertension due to cirrhosis. Areas covered: A literature search focused on liver and spleen stiffness measurement with different elastographic techniques for the assessment of the presence and severity of portal hypertension and oesophageal varices in people with chronic liver disease. The combination of elastography with parameters such as platelet count and spleen size is also discussed. Expert commentary: Non-invasive assessment of liver fibrosis and portal hypertension is a validated tool for the diagnosis and follow-up of patients. Baveno VI recommended the combination of transient elastography and platelet count for ruling out varices needing treatment in patients with compensated advanced chronic liver disease. Assessment of aetiology specific cut-offs for ruling in and ruling out clinically significant portal hypertension is an unmet clinical need. The incorporation of spleen stiffness measurements in non-invasive algorithms using validated software and improved measuring scales might enhance the non-invasive diagnosis of portal hypertension in the next 5 years.

Clinical factors that influence the outcome of selective devascularization in the treatment of portal hypertension

There is a high incidence of death due to variceal hemorrhage in patients with portal hypertension. Factors to consider when choosing selective devascularization in the treatment of variceal hemorrhage remain a controversy. This study aims to generate the prevalent clinical risk factors that affect the outcomes of selective devascularization procedures. Elucidating these features may guide future treatment of esophageal varices in patients with portal hypertension. We retrospectively analyzed medical records of 455 patients who underwent selective devascularization procedures in our center. Patients were subject to splenectomy, selective devascularization with or without esophageal transection. The mode of surgery recurred in comparable rates in both the group with major complications postoperatively (high-risk group which consisted of 63 patients) or the group without major postoperative complications (low-risk group, 392). Risk factors that negatively influenced outcomes of surgery include severe symptoms (89% in high risk group and 71% in low risk group), large volume of blood loss in the hemorrhage before surgery (81% in high risk group and 16% in low risk group), sever liver cirrhosis (83% in high risk group and 67% in low risk group), previous endotherapy, prolonged prothrombin time, and poor liver function. Selective devascularization is a feasible option to treat variceal hemorrhage in patients with portal hypertension.

Transjugular intrahepatic portosystemic shunts (TIPS) for the prevention of variceal re-bleeding - A two decades experience

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic shunts (TIPS) are used in patients with cirrhosis for the prevention of variceal rebleeding.

METHODS

We retrospectively evaluated re-bleeding rate, patency, mortality, and transplant-free survival (TFS) in cirrhotic patients receiving TIPS implantation for variceal bleeding between 1994-2014.

RESULTS

286 patients received TIPS (n = 119 bare metal stents, n = 167 polytetrafluorethylene (PTFE)-covered stents) for prevention of variceal re-bleeding. Mean age was 55.1 years, median MELD was 11.8, and the main etiology of cirrhosis was alcoholic liver disease (70%). Median follow-up was 821 days. 67 patients (23%) experienced at least one re-bleeding event. Patients with PTFE-TIPS were at significantly lower risk for variceal re-bleeding than patients with bare metal stents (14% vs. 37%, OR:0.259; p<0.001) and had less need for stent revision (21% vs. 37%; p = 0.024). Patients with PTFE stent grafts showed lower mortality than patients with bare stents after 1 year (19% vs. 31%, p = 0.020) and 2 years (29% vs. 40%; p = 0.041) after TIPS implantation. Occurrence of hepatic encephalopathy after TIPS was similar between groups (20% vs. 24%, p = 0.449).

CONCLUSIONS

PTFE-TIPS were more effective at preventing variceal re-bleeding than bare metal stents due to better patency. Since this tended to translate in improved survival, only covered stents should be implemented for bleeding prophylaxis when TIPS is indicated.

Spleen stiffness is positively correlated with HVPG and decreases significantly after TIPS implantation

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is indicated in patients with decompensated portal hypertension (PH). Hepatic venous pressure gradient (HVPG) is considered gold standard for assessment of PH. Because HVPG measurement is invasive, non-invasive methods for evaluating severity of PH are warranted.

PATIENTS AND METHODS

We retrospectively correlated spleen stiffness as measured by FibroScan with HVPG in patients who underwent TIPS. Twenty-four patients with spleen stiffness measurement (SSM) one day before (D-1), one day after (D+1) and 28 days after TIPS (D+28) were included.

RESULTS

SSM was positively correlated with pre-TIPS HVPG (HVPG <13mmHg, median SSM: 19.7±8.6kPa; HVPG 13-24mmHg, median SSM: 45.0±15.7kPa; HVPG >24mmHg, median SSM: 75.0±6.2kPa; p<0.05]; r²=0.72; p<0.001) and decreased significantly after TIPS implantation (D-1, median SSM: 67.1±17.3kPa; D+1, median SSM: 44.7±18.5kPa; D+28, median SSM: 35.6±17.0kPa; p<0.05), while liver stiffness measurement decrease was not statistically significant.

CONCLUSIONS

Our study highlights the utility of SSM as non-invasive tool in patients with chronic liver disease in evaluating degree of PH potentially offering a confirmable additional parameter in surveillance of patients undergoing TIPS procedure.

Gas6 as a predictor of esophageal varices in patients affected by hepatitis C virus related-chronic liver disease

AIM

Plasma Gas6 was tested as an alternative to Baveno VI criteria (liver stiffness <20 kPa and platelet count >150 × 10⁹/l) in an endoscopy-sparing strategy.

METHODS

 A total of 160 patients with chronic hepatitis C and advanced fibrosis/cirrhosis underwent, on the same occasion, liver elastography, upper endoscopy, a platelet count and serum Gas6 measurement.

RESULTS

 A total of 74/160 (46%) patients had esophageal varices, that were small (diameter <5 mm) in 57/160 (34%) and large in 17/160 (11%) cases. A total of 34/160 (21%) patients satisfied Baveno VI criteria, according to which screening for esophageal varices could have been omitted; 1/34 had large varices (sensitivity 94%). A plasma Gas6 value <45 ng/ml, detected in 34/160 (21%) patients, was also 94% sensitive.

CONCLUSION

Plasma Gas6 might represent a feasible alternative to Baveno VI criteria when transient elastography is unavailable/unsuccessful.

The Best Single Measurement for Assessing Splenomegaly in Patients with Cirrhotic Liver Morphology

RATIONALE AND OBJECTIVES

There is little agreement within the radiology literature as to the best single measurement for assessing splenomegaly. In this study, we evaluate the correlation of multiple unidirectional measurements of the spleen with splenic volume in patients with cirrhotic liver morphology on computed tomography (CT).

MATERIALS AND METHODS

Splenic volume was retrospectively calculated from CT examinations of 179 adult patients, 47 of whom were approved as renal donors, and 132 of whom were referred for various other indications, and were found to have cirrhotic liver morphology on CT. Seven unidimensional measurements (long-axis, cranial-caudal, width, and four measures of thickness) of each spleen were evaluated to identify which most closely correlated with the calculated volume.

RESULTS

The splenic width had the best correlation with splenic volume for mild-to-moderate splenomegaly, and the splenic cranial-caudal measurement had the best correlation with splenic volume for massive splenomegaly. Receiver operating characteristic analysis demonstrates that a splenic width measurement of approximately 10.5 cm has a sensitivity of 89% and a specificity of 78% for mild-to-moderate splenomegaly, and a cranial-caudal measurement of 14.6 cm has a sensitivity of 92% and a specificity of 91% for massive splenomegaly.

CONCLUSIONS

A splenic width threshold of 10.5 cm is the most sensitive (89%) and specific (78%) single measurement for mild-to-moderate splenomegaly in patients with cirrhotic liver morphology, whereas a cranial-caudal height threshold of 14.6 cm is the most sensitive (92%) and specific (91%) single measurement for massive splenomegaly.

Advances and challenges in cirrhosis and portal hypertension

BACKGROUND

Liver cirrhosis is the fourth cause of death in adults in Western countries, with complications of portal hypertension being responsible for most casualties. In order to reduce mortality, development of accurate diagnostic methods for early diagnosis, effective etiologic treatment, improved pharmacological therapy for portal hypertension, and effective therapies for end-stage liver failure are required.

DISCUSSION

Early detection of cirrhosis and portal hypertension is now possible using simple non-invasive methods, leading to the advancement of individualized risk stratification in clinical practice. Despite previous assumptions, cirrhosis can regress if its etiologic cause is effectively removed. Nevertheless, while this is now possible for cirrhosis caused by chronic hepatitis C, the incidence of cirrhosis due to non-alcoholic steatohepatitis has increased dramatically and effective therapies are not yet available. New drugs acting on the dynamic component of hepatic vascular resistance are being studied and will likely improve the future management of portal hypertension.

CONCLUSION

Cirrhosis is now seen as a dynamic disease able to progress and regress between the compensated and decompensated stages. This opinion article aims to provide the author's personal view of the current major advances and challenges in this field.

Imaging biomarkers in liver fibrosis

There is a need for early identification of patients with chronic liver diseases due to their increasing prevalence and morbidity-mortality. The degree of liver fibrosis determines the prognosis and therapeutic options in this population. Liver biopsy represents the reference standard for fibrosis staging. However, given its limitations and complications, different non-invasive methods have been developed recently for the in vivo quantification of fibrosis. Due to their precision and reliability, biomarkers' measurements derived from Ultrasound and Magnetic Resonance stand out. This article reviews the different acquisition techniques and image processing methods currently used in the evaluation of liver fibrosis, focusing on their diagnostic performance, applicability and clinical value. In order to properly interpret their results in the appropriate clinical context, it seems necessary to understand the techniques and their quality parameters, the standardization and validation of the measurement units and the quality control of the methodological problems.

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.

A computational model of the hepatic circulation applied to analyze the sensitivity of hepatic venous pressure gradient (HVPG) in liver cirrhosis

Measurement of hepatic venous pressure gradient (HVPG) is currently widely adopted to provide an estimate of portal pressure gradient (PPG) in the diagnosis and treatment of portal hypertension associated with liver cirrhosis. Despite the well-documented clinical utility of HVPG, it remains poorly understood how the relationship between HVPG and PPG is affected by factors involved in the pathogenesis and progression of cirrhosis. In the study, a computational model of the hepatic circulation calibrated to in vivo data was developed to simulate the procedure of HVPG measurement and quantitatively investigate the error of HVPG relative to PPG under various pathophysiological conditions. Obtained results confirmed the clinical consensus that HVPG is applicable to the assessment of portal hypertension caused by increased vascular resistance located primarily at the sinusoidal and postsinusoidal sites rather than at the presinusoidal site. On the other hand, our study demonstrated that the accuracy of HVPG measurement was influenced by many factors related to hepatic hemodynamics even in the case of sinusoidal portal hypertension. For instance, varying presinusoidal portal vascular resistance significantly altered the difference between HVPG and PPG, while an enhancement in portosystemic collateral flow tended to improve the accuracy of HVPG measurement. Moreover, it was found that presinusoidal and postsinusoidal vascular resistances interfered with each other with respect to their influence on HVPG measurement. These findings suggest that one should take into account patient-specific pathological conditions in order to achieve a better understanding and utilization of HVPG in the clinical practice.

Single-Session Percutaneous Endovascular Mesocaval Shunt Creation and Balloon-Occluded Retrograde Transvenous Obliteration for the Treatment of Gastric Varices

In the setting of portal hypertension, the body responds by creating portosystemic venous shunts, which may lead to the development of varices. Endoscopic treatment of these varices is often warranted to prevent catastrophic bleeding. During the course of variceal treatment, 1 or more portosystemic shunts may be sacrificed, which may acutely exacerbate portal hypertension and reduce systemic venous return. This report describes percutaneous creation of a mesocaval shunt and balloon-occluded retrograde transvenous obliteration (BRTO) in a patient with cavernous transformation of the portal vein. The patient had previously undergone an unsuccessful attempt at transjugular intrahepatic portosystemic shunt (TIPS) creation with postoperative bleeding requiring splenectomy. As TIPS was not feasible, creation of a percutaneous mesocaval shunt provided an alternate pathway for portosystemic decompression, facilitating safe treatment of gastric varices with BRTO via a gastrorenal shunt. These procedures were performed simultaneously to reduce the risk of variceal bleeding from acute changes in portal venous pressures and redirect blood flow through the shunt to maintain patency. This is the first reported case of combined mesocaval shunt placement and BRTO in a single session.

Non-invasive evaluation of portal hypertension using ultrasound elastography

Portal hypertension (PH) leads to serious complications, such as bleeding from gastroesophageal varices, ascites and portosystemic encephalopathy in patients with chronic liver disease (CLD). Gold standard methods for assessing PH and its complications include the measurement of hepatic venous pressure gradient and endoscopy; however, these are invasive, expensive and not available at all centres. Therefore, non-invasive alternatives have been the subject of extensive investigation over the last 20years. The present review focuses on the role of ultrasound elastography - a novel group of non-invasive techniques used to measure stiffness in target organs. In the context of CLD these methods are used to identify the presence of PH, its severity, and the risk of PH-related complications. The rationale, accumulated evidence, advantages and limitations of liver and spleen stiffness measurements evaluated by different ultrasound elastography techniques in patients with advanced CLD is discussed. Recent data regarding the use of ultrasound elastography techniques in patients with non-cirrhotic forms of PH are also described.

Diagnostic and therapeutic features of small bowel involvement in portal hypertension

Enteropathy is a lesser known complication of portal hypertension and consists of different changes in the mucosal layer of the small bowel which lead to the appearance of vascular and inflammatory lesions. It can be an important co-factor in the development of anemia in the cirrhotic population, and nowadays an easy and non-invasive diagnosis can be made thanks to capsule endoscopy. However, it is rarely considered in the management of patients with portal hypertension. Some aspects such as pathogenesis or incidence remain unclear and no specific recommendations are included in the guidelines regarding diagnosis or treatment. A review of the available literature was performed with regards to the most relevant aspects of this entity.

Endoscopic Ultrasound-Guided Direct Portal Pressure Measurement Using a Digital Pressure Wire with Real-Time Remote Display: A Survival Study

BACKGROUND

Portal hypertension is necessary for the development of most clinical complications of cirrhosis. We recently reported a novel, endoscopic ultrasound (EUS)-guided technique for direct portal pressure measurements using a digital pressure wire.

AIMS

The aims of this study were to (1) evaluate safety in an animal survival model and (2) compare direct portal vein (PV) versus transhepatic access of a first-order venule.

MATERIALS AND METHODS

Yorkshire pigs, weighing 40-55 kg. Procedures were performed under general anesthesia. PV was identified using a linear array echoendoscope and accessed with a 22-G fine needle aspiration needle preloaded with a digital pressure wire. Access was confirmed by portal venography. Mean digital pressure measurements were recorded over 30 seconds, and again after accessing a first-order portal venule in a transhepatic manner. Procedure times and video logs were maintained throughout. Animals were survived for 2 weeks. Repeat portal pressure measurements were performed before euthanasia and necropsy.

RESULTS

EUS-guided portal pressure measurements ranged from 3 to 11 mm Hg (mean 6.1) and were performed in a mean time of 214 seconds. There was no difference in measurement between the PV and first-order venule, or between baseline and 2-week follow-up. Five of 5 animals survived without incident. On necropsy, there was no evidence of thrombus or hemorrhage.

CONCLUSIONS

This study represents the first survival study after EUS-guided direct portal pressure measurements using a digital pressure wire. This method appears safe, straightforward, and precise. Measurements of the PV and a first-order portal venule appear equivalent, and serial measurement seems feasible.

Diagnosis of cirrhosis and portal hypertension: imaging, non-invasive markers of fibrosis and liver biopsy

The concept of ‘cirrhosis’ is evolving and it is now clear that compensated and decompensated cirrhosis are completely different in terms of prognosis. Furthermore, the term ‘advanced chronic liver disease (ACLD)’ better reflects the continuum of histological changes occurring in the liver, which continue to progress even after cirrhosis has developed, and might regress after removing the etiological factor causing the liver disease. In compensated ACLD, portal hypertension marks the progression to a stage with higher risk of clinical complication and requires an appropriate evaluation and treatment. Invasive tests to diagnose cirrhosis (liver biopsy) and portal hypertension (hepatic venous pressure gradient measurement and endoscopy) remain of crucial importance in several difficult clinical scenarios, but their need can be reduced by using different non-invasive tests in standard cases. Among non-invasive tests, the accepted use, major limitations and major benefits of serum markers of fibrosis, elastography and imaging methods are summarized in the present review.

Portal hypertension: Imaging of portosystemic collateral pathways and associated image-guided therapy

Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-pressure systemic veins. Through a variety of computed tomographic, sonographic, magnetic resonance imaging and angiographic examples, this article discusses the appearances and prevalence of both common and less common portosystemic collateral channels in the thorax and abdomen. A brief overview of established interventional radiologic techniques for treatment of portal hypertension will also be provided. Awareness of the various imaging manifestations of portal hypertension can be helpful for assessing overall prognosis and planning proper management.

Variables Associated With Inpatient and Outpatient Resource Utilization Among Medicare Beneficiaries With Nonalcoholic Fatty Liver Disease With or Without Cirrhosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide with tremendous clinical burden. The economic burden of NAFLD is not well studied.

GOAL

To assess the economic burden of NAFLD.

STUDY

Medicare beneficiaries (January 1, 2010 to December 31, 2010) with NAFLD diagnosis by International Classification of Diseases, Ninth Revision codes in the absence of other liver diseases were selected. Inpatient and outpatient resource utilization parameters were total charges and total provider payments. NAFLD patients with compensated cirrhosis (CC) were compared with decompensated cirrhosis (DC).

RESULTS

A total of 976 inpatients and 4742 outpatients with NAFLD were included-87% were white, 36% male, 30% had cardiovascular disease (CVD) or metabolic syndrome conditions, and 12% had cirrhosis. For inpatients, median total hospital charge was $36,289. NAFLD patients with cirrhosis had higher charges and payments than noncirrhotic NAFLD patients ($61,151 vs. $33,863 and $18,804 vs. $10,146, P<0.001). Compared with CC, NAFLD patients with DC had higher charges and payments (P<0.02). For outpatients, median total charge was $9,011. NAFLD patients with cirrhosis had higher charges and payments than noncirrhotic NAFLD patients ($12,049 vs. $8,830 and $2,586 vs. $1,734, P<0.001). Compared with CC, DC patients had higher total charges ($15,187 vs. $10,379, P=0.04). In multivariate analysis, variables associated with increased inpatient resource utilization were inpatient mortality, DC, and CVD; for outpatients, having CVD, obesity, and hypertension (all P<0.001).

CONCLUSIONS

NAFLD is associated with significant economic burden to Medicare. Presence of cirrhosis and CVD are associated with increased resource utilization.

Factors Associated With Bleeding Secondary to Rupture of Esophageal Varices in Children and Adolescents With Cirrhosis

OBJECTIVE

Bleeding of esophageal varices is the main cause of morbidity and mortality in children with portal hypertension. It is important to understand the factors related with a bleeding episode to evaluate more effective primary prophylaxis. The present study aims to describe the endoscopic and laboratory findings associated with upper gastrointestinal bleeding (UGIB) secondary to esophageal varices.

METHOD

A cross-sectional study with 103 children and adolescents with cirrhosis, divided into a group that had experienced an episode of upper UGIB (35 patients) and a group without a history of UGIB (68 patients), was carried out. The esophageal and gastric varices were classified, and the portal hypertensive gastropathy, laboratory findings, and Child-Pugh classification were measured.

RESULTS

Factors observed in univariate analysis to be associated with UGIB were the presence of esophageal varices of medium caliber or larger, portal hypertensive gastropathy, presence of red spots on esophageal varices, Child-Pugh class B or C, and hypoalbuminemia (P < 0.05). After multivariate logistic regression analysis, the significant factors were the presence of red spots on esophageal varices and the presence of gastric varices. When separated the autoimmune hepatitis, nonbiliary atresia patients (all patients except the patients with biliary atresia), and biliary atresia groups the findings in the univariate analysis were the presence of esophageal varices of medium or larger caliber, presence of red spots on varices, and presence of gastric varices in the autoimmune hepatitis patients and nonbiliary atresia patients and presence of red spots on esophageal varices, presence of gastric varices, and Child-Pugh classification B or C in biliary atresia group (P < 0.05). After multivariate logistic regression analysis, no statistical significance was found for any factor analyzed in any groups.

CONCLUSIONS

The presence of gastric varices and red spots on esophageal varices were related to episodes of UGIB secondary to rupture of esophageal varices. When these findings are observed, indications for endoscopic primary prophylaxis should be evaluated. More studies are, however, necessary to better understand this problem.

Clinical role of non-invasive assessment of portal hypertension

Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimated. However, it is an invasive procedure that requires significant hospital resources, including experienced staff, and is associated with considerable cost. Non-invasive methods that can be reliably used to estimate the presence and the degree of portal hypertension are urgently needed in clinical practice. Biochemical and morphological parameters have been proposed for this purpose, but have shown disappointing results overall. Splanchnic Doppler ultrasonography and the analysis of microbubble contrast agent kinetics with contrast-enhanced ultrasonography have shown better accuracy for the evaluation of patients with portal hypertension. A key advancement in the non-invasive evaluation of portal hypertension has been the introduction in clinical practice of methods able to measure stiffness in the liver, as well as stiffness/congestion in the spleen. According to the data published to date, it appears to be possible to rule out clinically significant portal hypertension in patients with cirrhosis (i.e., hepatic venous pressure gradient ≥ 10 mmHg) with a level of clinically-acceptable accuracy by combining measurements of liver stiffness and spleen stiffness along with Doppler ultrasound evaluation. It is probable that the combination of these methods may also allow for the identification of patients with the most serious degree of portal hypertension, and ongoing research is helping to ensure progress in this field.

EUS-guided intrahepatic portosystemic shunt with direct portal pressure measurements: a novel alternative to transjugular intrahepatic portosystemic shunting

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic shunting involves the creation of a low-resistance channel between the portal vein (PV) and the hepatic vein (HV), and is routinely performed under angiography. The aims were to evaluate (1) safety and technical feasibility; (2) procedural duration; and (3) subjective workload assessment of EUS-guided intrahepatic portosystemic shunt (EIPS).

METHODS

Five Yorkshire pigs were used in the study. The HV or inferior vena cava (IVC) was identified using a linear-array echoendoscope and accessed with a 19-G FNA needle preloaded with a digital pressure wire. Mean pressure was recorded. The needle was advanced into the PV, where pressure measurements were again taken, and ultimately exchanged over a guidewire. A lumen-apposing metal stent was deployed under EUS and fluoroscopic guidance, with distal and proximal ends positioned inside the PV and HV (IVC), respectively. Dilation was performed, and pressure measurements repeated. The National Aeronautics and Space Administration (NASA) Task Load Index (TLI) was scored. Animals survived 2 weeks before necropsy.

RESULTS

EIPS was successful in 5 out of 5 pigs. Mean time required for EUS identification, needle access, pressure measurement, and stent placement was 43 (31-55) minutes. NASA TLI scores revealed moderate workload. Mean baseline pressure measurements were PV 7.0 (5-9) and HV/IVC 5.0 (3-7) mm Hg and PV 6.3 (5-7) and HV/IVC 6.0 (4-7) mm Hg after. All animals survived 2 weeks. No bleeding was seen on necropsy.

CONCLUSIONS

This study demonstrates the technical feasibility of EIPS using LAMS, with direct portal pressure measurement, in a survival model. In addition, the procedure was performed quickly with moderate technical demand.

[Portopulmonary hypertension: Updated review]

Portopulmonary hypertension (PPH) is a rare condition worldwide, although epidemiological data are unknown in Mexico. However, chronic liver diseases are very prevalent in Mexico. PPH is the 4th subtype in frequency in the group of pulmonary arterial hypertension. Its diagnosis is made within 2 scenarios: patients with suspected pulmonary hypertension and candidates for orthotopic liver transplantation (OLT). Both echocardiogram and a right cardiac catheterisation are crucial for diagnosis in both cases. PPH is a challenge for OLT, since it can significantly increase perioperative mortality. The use of specific therapy is the cornerstone of this disease, as a measure to improve the outcome of those who become candidates for OLT with moderate to severe PPH. It is important to recognise that PPH can be a contraindication to OLT. The role of lung-liver transplantation or heart-lung-liver transplantation as a measure to heal pulmonary vascular disease in patients with PPH is still uncertain.

Normal main portal vein diameter measured on CT is larger than the widely referenced upper limit of 13 mm

OBJECTIVE

We determined mean main portal vein diameter in healthy patients evaluated with CT, compared this value to the "upper limit of normal" reported previously, and evaluated effects of age, sex, height, and BMI on portal vein diameter.

MATERIALS AND METHODS

Our cohort of healthy patients underwent abdominal CT as potential renal donors. We excluded patients with evidence of liver or severe cardiac disease. We recorded patients' age, sex, height, weight, and BMI. Patients' main portal vein diameters were measured by fellowship-trained abdominal imagers on non-contrast and post-contrast images in axial and coronal projections at a defined location. A general linear mixed model was used for analysis.

RESULTS

191 patients with 679 main portal vein measurements were included in the analysis. Mean main portal vein diameter was 15.5 ± 1.9 mm; this value was significantly different from the upper limit of normal of 13 mm commonly referenced in the literature (95% CI: 2.22-2.69 mm higher, p < 0.0001). Portal vein diameter does not vary significantly when measured on axial vs. coronal images. On average, post-contrast main portal veins were 0.56 mm larger compared to non-contrast, (95% CI: 0.40-0.71 mm, p < 0.0071). Patient height and BMI are positively correlated with MPV diameter.

CONCLUSIONS

Normal mean portal vein diameter measured on CT was significantly larger (mean 15.5 mm) than the accepted upper limit of 13 mm. Contrast-enhanced main portal veins are significantly larger (0.56 mm) than unenhanced. Sex, height, and BMI significantly affect main portal vein diameter.

Diagnosing native liver fibrosis and esophageal varices using liver and spleen stiffness measurements in biliary atresia: a pilot study

BACKGROUND

Biliary atresia commonly leads to liver fibrosis and cirrhotic complications, including esophageal varices.

OBJECTIVE

To evaluate liver and spleen stiffness measurements using acoustic radiation force impulse (ARFI) imaging for diagnosing grade of liver fibrosis and predicting the presence of esophageal varices in patients treated for biliary atresia.

MATERIALS AND METHODS

ARFI imaging of the spleen and native liver was performed in 28 patients with biliary atresia. We studied the relation between ARFI imaging values and liver histology findings (n=22), upper gastrointestinal endoscopy findings (n=16) and several noninvasive test results. Diagnostic accuracy was assessed using receiver operating characteristic curve analyses.

RESULTS

Liver stiffness measurements exhibited a significant difference among the different grades of liver fibrosis (P=0.009), and showed higher values in patients with high-risk esophageal varices than in the other patients (P=0.04). The areas under the receiver operating characteristic curves of liver stiffness measurements for liver fibrosis grades  ≥ F2, ≥F3 and = F4 were 0.83, 0.93 and 0.94, respectively. Patients with high-risk esophageal varices were preferentially diagnosed by the combined liver and spleen stiffness measurements (area under the curve, 0.92).

CONCLUSION

Liver and spleen stiffness measurements using ARFI imaging are potential noninvasive markers for liver fibrosis and esophageal varices in patients treated for biliary atresia.

Portal hypertensive gastropathy with a focus on management

Portal hypertensive gastropathy (PHG) is a painless condition of gastric mucosal ectasia and impaired mucosal defense, commonly seen in patients with elevated portal pressures. While it is typically asymptomatic and incidentally discovered on upper endoscopy, acute and chronic bleeding may occur. There are no definitive recommendations for treatment of asymptomatic PHG. Non-selective β-blockers represent the mainstay of therapy for chronic bleeding, while somatostatin and vasopressin and their derivatives may be used in conjunction with supportive measures for acute bleeding. Salvage therapy with transjugular intrahepatic portosystemic shunt or rarely surgical shunt is appropriate when medical management fails. The role of endoscopic therapy for PHG is controversial. Liver transplantation should be considered as a final resort in cases of refractory bleeding due to PHG.

EUS-guided portal pressure measurement using a digital pressure wire with real-time remote display: a novel, minimally invasive technique for direct measurement in an animal model

BACKGROUND AND AIMS

Hepatic venous pressure gradient (HVPG) currently serves as a surrogate for portal pressure measurement but has many limitations. We developed a novel technique for rapid and direct portal pressure measurements using a digital pressure wire delivered through an EUS-guided 22-gauge FNA needle. Our aims were to evaluate (1) the short-term safety and technical feasibility, (2) procedural duration and subjective workload assessment, and (3) accuracy compared with a transjugular criterion standard approach.

METHODS

The subjects were Yorkshire pigs, weighing 40 to 55 kg. The portal vein was identified by using a linear array echoendoscope and accessed with a commercially available 22-gauge FNA needle preloaded with a digital pressure wire. Access was confirmed by portal venography. Mean digital pressure measurements were recorded over 30 to 60 seconds, and the National Aeronautics and Space Administration Task Load Index was scored. The control measurements were conventional transjugular catheterization with a balloon occlusion catheter to obtain free and wedged hepatic pressures, with subsequent HVPG calculation.

RESULTS

The total time required for EUS identification and needle access of the portal vein, venography, and digital pressure measurement was less than 5 minutes in 5 of 5 pigs. The National Aeronautics and Space Administration Task Load Index scores revealed a low subjective workload. Baseline portal pressure measurements via EUS ranged from 5 mm Hg to 10 mm Hg (mean, 6.4 mm Hg). HVPG measurements were consistently ±1 mm Hg of portal pressure.

CONCLUSIONS

This study is the first report of direct EUS-guided portal pressure measurements by using a digital pressure wire. This method is routinely performed in minutes and provides real-time pressure tracings via wireless transmission. This novel approach for direct portal pressure measurement has the potential to replace traditional indirect HVPG measurements.

Liver surgery in cirrhosis and portal hypertension

The prevalence of hepatic cirrhosis in Europe and the United States, currently 250 patients per 100000 inhabitants, is steadily increasing. Thus, we observe a significant increase in patients with cirrhosis and portal hypertension needing liver resections for primary or metastatic lesions. However, extended liver resections in patients with underlying hepatic cirrhosis and portal hypertension still represent a medical challenge in regard to perioperative morbidity, surgical management and postoperative outcome. The Barcelona Clinic Liver Cancer classification recommends to restrict curative liver resections for hepatocellular carcinoma in cirrhotic patients to early tumor stages in patients with Child A cirrhosis not showing portal hypertension. However, during the last two decades, relevant improvements in preoperative diagnostic, perioperative hepatologic and intensive care management as well as in surgical techniques during hepatic resections have rendered even extended liver resections in higher-degree cirrhotic patients with portal hypertension possible. However, there are few standard indications for hepatic resections in cirrhotic patients and risk stratifications have to be performed in an interdisciplinary setting for each individual patient. We here review the indications, the preoperative risk-stratifications, the morbidity and the mortality of extended resections for primary and metastatic lesions in cirrhotic livers. Furthermore, we provide a review of literature on perioperative management in cirrhotic patients needing extrahepatic abdominal surgery and an overview of surgical options in the treatment of hepatic cirrhosis.

A non-invasive magnetic resonance imaging-based model predicts portal venous pressure

OBJECTIVE

To establish a non-invasive model for the assessment of portal venous pressure (PVP) based on the magnetic resonance (MR) parameters.

METHODS

In this prospective study, contrast-enhanced magnetic resonance imaging (MRI) scan was performed in 109 patients indicated for upper abdominal surgeries after their written consents were obtained, and intraoperative PVP measurements were completed in 92 patients. Altogether 17 patients were excluded for not undergoing surgery or unsuccessful catheterization. A linear model was constructed for estimating PVP levels in 56 patients and further validation was conducted in the other 36 patients.

RESULTS

The PVP levels were significantly correlated with MR parameters, including splenic volume (SV), splenic venous diameter (SVD), liver/splenic volume ratio, portal venous diameter, hepatic diameter, portal venous cross-sectional area, ascites, varices and arterial portal shunts. A linear model was established as follows: PVP (mmHg) = 2.529 + 1.572 × SVD (mm) + 0.231 × SV/body mass index (× 10(4) cm(5) /kg) + 3.44 × aspartate aminotransferase-to-platelet ratio index. This model showed excellent accuracy in the detection of portal hypertension, with the area under the receiver operating characteristic curve (AUROC) of 0.945 (95% CI 0.867-1.000), with the sensitivity and specificity of 91.7% and 93.7%, respectively. The agreement analysis revealed that the predictive value using this formula closely reflected the patients' actual PVP level. Moreover, the validation confirmed the accuracy of this model for the assessment of portal hypertension [AUROC 0.935 (95% CI 0.856-1.000)].

CONCLUSIONS

The MRI-based formula has great potential for detecting portal hypertension. As a non-invasive measurement, it may be clinically accepted for the replacement of invasive modalities after further refinement.

New combined parameter of liver and splenic stiffness as determined by elastography in healthy volunteers

BACKGROUND

The diagnosis of chronic liver disease (CLD) leading to fibrosis, cirrhosis, and portal hypertension had witnessed dramatic changes after the introduction of noninvasive figure accessible tools over the past few years. Imaging techniques that are based on evaluation of the liver stiffness was particularly useful in this respect. Acoustic radiation force impulse (ARFI) emerged as an interesting figure tool with reliable repute and high precision.

AIMS

To evaluate liver stiffness measurement (LSM) and splenic stiffness measurement (SSM) in healthy volunteers as concluded by the ARFI technique and to out a numeric calculated ratio that may reflect their correlation in the otherwise healthy liver.

PATIENTS AND METHODS

A ratio (splenic stiffness/liver stiffness in kPa) was determined in 207 consenting healthy subjects and was investigated with respect to age, gender, ethnic origin, body mass index (BMI), liver and spleen sizes healthy volunteers, alanine aminotransferase (ALT), aspartate aminotransferase (AST), platelet count (PLT), APRI, and FIB-4 scores.

RESULTS

Data from this work led to computing an index of 4.72 (3.42-7.33) in healthy persons on an average. Females had a higher index than males 6.37 vs 4.92, P=0.002. There was not any significant difference of the ratio in different age groups; ethnic origins; any correlation between SSM/LSM ratio and BMI; liver and spleen sizes; or ALT, AST, PLT, APRI, and FIB-4 scores.

CONCLUSIONS

A quantifiable numeric relationship between splenic and liver stiffness in the healthy subjects could be computed to a parameter expressed as SSM/LSM ratio. We believe that this ratio can be a useful reference tool for further researches in CLD.