Value of measurement of mean portal flow velocity by Doppler flowmetry in the diagnosis of portal hypertension

Portal hypertension-like pattern in coronavirus disease 2019 acute respiratory distress syndrome

OBJECTIVES

Although respiratory failure is the most common feature in coronavirus disease 2019 (COVID-19), abdominal organ involvement is likewise frequently observed. To investigate visceral and thoracic circulation and abdominal organ damage in COVID-19 patients.

MATERIALS AND METHODS

A monocentric observational study was carried on. In COVID-19 patients affected by acute respiratory distress syndrome (ARDS) (n = 31) or mild pneumonia (n = 60) thoracoabdominal circulation was evaluated using Doppler-ultrasound and computed tomography. The study also included non-COVID-19 patients affected by ARDS (n = 10) or portal hypertension (n = 10) for comparison of the main circulatory changes.

RESULTS

Patients affected by COVID-19 ARDS showed hyperdynamic visceral flow and increased portal velocity, hepatic artery resistance-index, and spleen diameter relative to those with mild-pneumonia (p = 0.001). Splanchnic circulatory parameters significantly correlated with the main respiratory indexes (p < 0.001) and pulmonary artery diameter (p = 0.02). The chest and abdominal vascular remodeling pattern of COVID-19 ARDS patients resembled the picture observed in the PH group, while differed from that of the non-COVID ARDS group. A more severe COVID-19 presentation was associated with worse liver dysfunction and enhanced inflammatory activation; these parameters both correlated with abdominal (p = 0.04) and chest imaging measures (p = 0.03).

CONCLUSION

In COVID-19 ARDS patients there are abdominal and lung vascular modifications that depict a portal hypertension-like pattern. The correlation between visceral vascular remodeling, pulmonary artery enlargement, and organ damage in these critically ill patients is consistent with a portal hyperlfow-like syndrome that could contribute to the peculiar characteristics of respiratory failure in these patients.

CLINICAL RELEVANCE STATEMENT

our data suggest that the severity of COVID-19 lung involvement is directly related to the development of a portal hyperflow-like syndrome. These observations should help in defining the need for a closer monitoring, but also to develop dedicated therapeutic strategies.

Portal Vein Thrombosis in Patients With Cirrhosis of the Liver: Prevalence and Risk Factors

INTRODUCTION

Chronic liver disease very often culminates into cirrhosis and its associated complications. One of the serious complications is portal venous thrombosis, which can occur due to a variety of risk factors. One significant factor contributing to portal hypertension is portal vein thrombosis (PVT). In this study, we aimed to investigate the prevalence of PVT among patients with liver cirrhosis in a tertiary hospital and identify the factors associated with this complication.

METHODOLOGY

This was a cross-sectional observational study of 93 diagnosed liver cirrhosis patients treated at Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER) hospital in southern India between June 2020 and January 2021. A thorough evaluation of the clinical condition of the patients and associated comorbidities was done. The patients then underwent Doppler ultrasound/CECT/MRI to look for PVT and its extent. The collected data were analyzed using Statistical Product and Service Solutions (SPSS, version 24) (IBM SPSS Statistics for Windows, Armonk, NY). Comparison between two proportions was done using two two-tailed Z-test/Fisher's exact tests.

RESULTS

Our study found a PVT prevalence of 17.2% in cirrhotic patients, with a higher prevalence of acute PVT than chronic PVT. Ascitic fluid infection, longer duration of cirrhosis, and increased cirrhosis severity were significantly associated with PVT development. We found no significant associations between PVT and gender, hypertension, smoking, diabetes, or the duration of alcohol intake.

CONCLUSION

This study highlights the importance of early screening for PVT using Doppler USG in all patients diagnosed with cirrhosis. Additionally, anticoagulation therapy for acute PVT may be considered in patients without bleeding risks.

A systematic review and meta-analysis of portal vein morphometry in pediatric and adult populations: Drawing the line between normal and abnormal findings

PURPOSE

The morphometry of the hepatic portal vein is of clinical importance, particularly in pre-operative assessments, surgical management, and diagnoses of liver conditions. This systematic review and meta-analysis aimed to characterize the morphometry of the normal portal vein in both pediatric and adult patients.

METHODS

The study, conducted using the PRISMA guidelines and registered with PROSPERO, utilized the MEDLINE, EMBASE, SCOPUS and Web of Science databases up to May 2020, and updated to May 2023. All studies reporting extractable data on diameter, length, and cross-sectional area (CSA) of the main, left, and right portal veins (PV, LPV, RPV, respectively) were included. The AQUA Tool was used to assess the quality of the included studies. Data analysis included subgroup analyses based on geographical location, sex, age, and imaging modality.

RESULTS

A total of 122 studies with 11,637 subjects were eligible for inclusion. Overall, the pooled mean diameter of the PV (PVD) was 10.09 mm (95% CI: 9.56-10.62). Significant differences in diameter were found between pediatric (6.60 mm; 95% CI: 5.38-7.82) and adult (10.72 mm; 95% CI: 10.25-11.19) subjects. Additionally, there was a significantly larger PVD measurement from computed tomography (CT) than other imaging modalities: CT, 13.28 mm (95% CI: 11.71-14.84); magnetic resonance imaging (MRI), 10.50 mm (95% CI: 9.35-11.66) and ultrasound (US), 9.81 mm (95% CI: 9.47-10.16). The mean diameters of the LPV and RPV were 8.27 mm (95% CI: 6.78-9.77) and 8.33 mm (95% CI: 6.70-9.95), respectively. Mean PV length in adults is 48.63 mm (95% CI: 35.63-61.64). Mean CSA of the PV was 1.09 cm2.

CONCLUSIONS

The study obtained aim to improve the understanding of portal vein anatomy, especially with relevance to surgical interventions of the liver in both pediatric and adult patients. Measurements from ultrasound imaging closely approximates the generated pooled PVD mean for pediatric and adult patients. CT imaging, however, significantly exceeded the established 13 mm threshold for adults. For pediatric patients, a threshold of 8 mm is proposed as a diagnostic upper limit for a normal PVD. Although not significant, the PVD decreased from the portal confluence towards its bifurcation.

Beyond conventional physical examination in hepatology: POCUS

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

Do the stent blind insertion into the main portal vein (MPV) and stent diameter influence the surgical outcome of the transjugular intrahepatic portosystemic shunt (TIPS)?

Transjugular intrahepatic portosystemic shunt (TIPS) surgery is a clinical intervention to treat portal hypertension (PH) by deploying a covered stent to establish a shunt path for the portal vein (PV) system, and proper surgical strategy is of great importance to balance the shunt effect and the risk of complications. To understand the clinical strategies of the stent blind insertion and stent selection in clinic, this study investigated the effects of varying stent insertion positions and diameters on the PV hemodynamics and the shunt effect by computational fluid dynamics (CFD) analysis of five post-TIPS subjects. The results showed that the successful TIPS surgeries of the five PH subjects were confirmed by quantifying their pressure drops. The stent insertion positions at the main portal vein (MPV) slightly affected the clinically concerned hemodynamic indexes (i.e., MPV pressure, stent-outlet velocity) and the shunt index (SI). This indicated that the position of the stent going into the MPV may not need to be deliberately selected. Moreover, the covered stents with 6 mm and 8 mm diameters slightly influenced the hemodynamics as well, but the large-diameter stent better improved the shunt effect compared to the small-diameter one. Despite this, the 6 mm stent was suggested thanks to the higher risk of the hepatic encephalopathy (HE) observed in clinic, which indicated the excessive shunt of the 8 mm stent. The current work revealed the effects of different TIPS strategies on the surgical outcome, and could be useful for potential clinical practices.

Measurement of Pulsating Flow Using a Self-Attachable Flexible Strain Sensor Based on Adhesive PDMS and CNT

Accurate monitoring is needed for pulsating flow in many healthcare and bio applications. Specifically, real-time monitoring of pulsating blood flow provides rich information regarding a patient’s health conditions. This paper proposes a flexible strain sensor capable of detecting the pulsating fluid flow by directly measuring the circumferential strain induced by a rapid change in the flow rate. The thin and flexible strain sensor consists of a polydimethylsiloxane (PDMS) with a Triton-X treatment to enhance the adhesive property and multi-walled carbon nanotubes (MWCNT) as the piezoresistive sensing layer. MWCNT integration implements a simple spray-coating method. The adhesive PDMS/CNT strain sensor exhibits a highly adhesive nature and can be attached to a silicone tube’s curved surface. By analyzing the theoretical modeling based on fluid energy equation and solid mechanics, strains induced on the soft tube by the change in flow rate, viscosity, and fluid density can be predicted. We performed the flow rate measurement at varying fluid-flow rates and liquid viscosities, and the results match our prediction. The sensitivity and limit of detection of the presented strain sensor are about 0.55 %min/L and 0.4 L/min, respectively. Both the calculation and experiment confirm that the sensor resistance is most sensitive to the fluid-flow rate, thus, enabling the accurate tracking of pulsating fluids’ flow rate, regardless of the viscosity or density.

Noninvasive imaging of hepatic dysfunction: A state-of-the-art review

Hepatic dysfunction represents a wide spectrum of pathological changes, which can be frequently found in hepatitis, cholestasis, metabolic diseases, and focal liver lesions. As hepatic dysfunction is often clinically silent until advanced stages, there remains an unmet need to identify affected patients at early stages to enable individualized intervention which can improve prognosis. Passive liver function tests include biochemical parameters and clinical grading systems (e.g., the Child-Pugh score and Model for End-Stage Liver Disease score). Despite widely used and readily available, these approaches provide indirect and limited information regarding hepatic function. Dynamic quantitative tests of liver function are based on clearance capacity tests such as the indocyanine green (ICG) clearance test. However, controversial results have been reported for the ICG clearance test in relation with clinical outcome and the accuracy is easily affected by various factors. Imaging techniques, including ultrasound, computed tomography, and magnetic resonance imaging, allow morphological and functional assessment of the entire hepatobiliary system, hence demonstrating great potential in evaluating hepatic dysfunction noninvasively. In this article, we provide a state-of-the-art summary of noninvasive imaging modalities for hepatic dysfunction assessment along the pathophysiological track, with special emphasis on the imaging modality comparison and selection for each clinical scenario.

Application of ultrasound for the diagnosis of cirrhosis/portal hypertension

With advances in technologic approaches in patients with cirrhosis, including the improvement of management, a simple, one-step approach for advanced fibrotic state of the liver is clinically useful. Although refining the diagnosis of cirrhosis to reflect disease heterogeneity is essential, current diagnostic tests have not kept pace with the progression of this new paradigm. There are unmet needs in primary care centers with respect to patients with cirrhosis. Liver biopsy and measurement of hepatic venous pressure gradient in patients with cirrhosis are the gold standards for the estimation of hepatic fibrosis, and they have diagnostic and prognostic value. However, both approaches are invasive and cannot be used repeatedly in clinical practice. Ultrasonography (US) is safe, easy to perform, inexpensive, and yields numerical and accurate results. Conventionally, the size of the liver and spleen, bluntness of the liver edge, nodularity of the liver surface, and coarseness of the liver parenchyma have been known as useful parameters for hepatic fibrosis or portal hypertension (PHT) in chronic liver disease. Additionally, some functional US indices including Doppler and CEUS-based examination have been suggested as promising markers for diagnosing cirrhosis and PHT. Identification of the reproducibility and long-term prognostic value through further investigations can demonstrate the clinical usefulness of functional US indices, which are characterized as quantitative parameters for hepatic fibrosis and PHT.

Non-invasive assessment of liver abnormalities in pediatric Fontan patients

Liver abnormalities are well known among long-term survivors of Fontan palliation, which remains the definite surgery for complex congenital heart disease and single ventricle physiology. Pediatric data however are scarce. We assessed the prevalence and degree of liver abnormalities in pediatric Fontan patients through non-invasive investigations suitable for longitudinal follow-up. Thirty-five patients with a median age of 11.8 years (5.2-16.6) and median time since Fontan of 6 years (1.17-13.83) were studied. Each child underwent a blood test, liver Doppler ultrasound (US), and transient elastography (TE). Healthy children were used as controls for TE measurement. AST, ALT, γGT, and direct bilirubin were abnormal in respectively 12 (34%), 5 (14%), 24 (69%), and 7 (20%) patients, while platelet count was decreased in 7 (20%). Splenomegaly was present in 7 (20%) patients. Portal vein mean flow velocity was < 15 cm/s in 19 (54%) patients indicative of portal hypertension. Twenty-two patients (63%) showed inferior vena cava collapsibility index values below 17%, indicating venous congestion. Hepatic artery and superior mesenteric artery resistance index were inversely correlated with time post Fontan (p < 0.05). TE values in Fontan patients were significantly higher than controls, with a median of 12.6 versus 4.6 kPa (p < 0.001) and were already increased shortly after Fontan completion. Conclusion: Liver abnormalities are frequently observed in pediatric Fontan patients. The non-invasive investigations used were not able to confirm liver fibrosis or differentiate hepatic congestion from fibrosis. Based on our findings, we propose a prospective screening protocol with serial measurements of laboratory, (Doppler) US, and TE parameters. What is Known: • Hepatic dysfunction is a well-known consequence of the Fontan circulation. • The natural history of Fontan-associated liver disease in the pediatric age group remains unclear. What is New: • Liver abnormalities are frequently observed in pediatric Fontan patients; however, differentiating liver fibrosis and hepatic congestion with non-invasive investigations remains challenging. Sonographic Doppler measurements may improve our insight in both Fontan-associated liver disease development and the functioning of the Fontan circulation. • A prospective screening protocol is proposed to improve our ability to detect Fontan-associated liver disease early on and understand its natural history.

Hepatic function predictive value of hepatic venous waveform versus portal vein velocity in liver cirrhosis

Background:

This study assessed the hepatic vein waveform (HVW) and mean maximum portal vein velocity (MM-PVV) on Doppler ultrasound in patients with liver cirrhosis (LC) and compared it with that of age and sex-matched controls. It correlated the degree of HVW abnormality and MM-PVV changes with liver function based on Child-Turcotte-Pugh (CTP) to determine which was more predictive of CTP.

Methods:

Sixty patients with LC and 60 healthy controls were consecutively recruited into this study. Each patient was classed based on the CTP system after relevant tests. Doppler evaluation of the hepatic vein (HV) and MM-PVV were performed. HVW obtained was classified either into triphasic, biphasic, or monophasic.

Results:

Sixty cirrhotic and 60 age-matched control subjects aged 19–69 and 18–69 years, respectively, completed this study. All control subjects had a normal HVW pattern while 46 (76.7%) cirrhotic subjects had abnormal HVW (P < 0.001). The MM-PVV was significantly lower in cirrhotic subjects than in controls; 22.8 cm/s versus 33.6 cm/s (P < 0.001). The degree of HVW abnormality among cirrhotics showed a significant positive correlation with CTP (r = 0.283, P = 0.029). MM-PVV on the other hand showed no correlation with CTP class (r = −0.124; P = 0.346). Linear regression showed that HVW was a significant predictor of hepatic dysfunction based on CTP.

Conclusion:

Changes in the waveform pattern of the HVs are a good predictor of the derangement of hepatic function in patients with LC than changes in PVV. HVW pattern could therefore serve as an adjunct to CTP class in hepatic function assessment.

Systemic inflammation as a risk factor for portal vein thrombosis in cirrhosis: a prospective longitudinal study

BACKGROUND AND AIMS

Various risk factors for portal vein thrombosis (PVT) development in patients with cirrhosis have been identified, but the role of systemic inflammatory reaction is unknown. The study aims to assess the association between markers of systemic inflammation and PVT in cirrhosis.

METHODS

Between January 2014 and October 2015, 107 outpatients with cirrhosis and no PVT were recruited, and followed till February 2017. White blood cell count, serum concentrations of high-sensitive C-reactive protein, ferritin, tumor necrosis factor-alpha and interleukin-6 (IL-6) were evaluated at baseline and every 3 or 6 months till PVT diagnosis or end of follow-up.

RESULTS

Median age, model for end-stage liver disease (MELD) score and follow-up period of the studied population was 55 years (IQR 46-62 years), 9.6 points (IQR 7.5-12 points) and 19 months (12-24 months), respectively. PVT developed in 10.3% of the patients. Lymphocyte count below 1.2 ´ 109/L [hazard ratio, 6.04; 95% confidence interval (CI), 1.29-28.2; P = 0.022], IL-6 above 5.5 pg/mL (hazard ratio, 5.64; 95% CI, 1.21-26.33; P  = 0.028) and neutrophil-to-lymphocyte ratio (hazard ratio, 1.46; 95% CI, 1.04-2.04; P = 0.028) were associated with a higher risk of PVT development. IL-6 and lymphopenia remained associated with subsequent PVT development after adjustment for nonselective beta-blockers, spleen size, portosystemic collaterals, oesophageal varices (grade ≥2) and ascites, but also with alcohol as the cause for cirrhosis and MELD ≥13.

CONCLUSION

In patients with cirrhosis, markers of systemic inflammation IL-6 and lymphopenia are predictive of PVT independently of markers of portal hypertension. These results draw our attention on a factor so far overlooked in the pathogenesis of PVT.

Portal Hypertension in Non-alcoholic Fatty Liver Disease in the Era of Non-invasive Assessment

Non-alcoholic fatty liver disease (NAFLD) is one of the emerging global health problems due to an increase of burden worldwide. It has been known that NAFLD is strongly associated with metabolic syndrome. The progression of NAFLD is a complex and multifactorial mechanism. Portal hypertension is still the main key in liver disease progression management. In NAFLD, portal hypertension might occur in the non-cirrhotic condition. Hepatic vein pressure gradient measurement has been considered as the gold standard for portal pressure assessment; however, due to its invasiveness and the need for a high-expertise centre, it is considered a non-practical measurement tool in clinical practice. Many other non-invasive parameters have been developed to replace the invasive measurement; however, there are still some limitations with regard to the technical issue, patient’s condition, and its accuracy in the different stages of the disease. Therefore, the authors review portal hypertension related to the clinical course of NAFLD, and the development of portal pressure evaluation in patients with NAFLD.

Doppler ultrasonography and contrast-enhanced ultrasonography to evaluate liver allograft discard: A pilot prospective study

BACKGROUND

Broad hemodynamic changes, is believed to have a profoundly damaging effect on donor livers after brain death (DBD) or cardiac death (DCD). It remains unclear whether Doppler ultrasonography (DUS) and contrast-enhanced ultrasonography (CEUS), the imaging modalities to evaluate perfusion, could provide more information of liver discarded.

OBJECTIVE

To evaluate the ability of DUS and CEUS to predict the risk of DBD or DCD liver discarded.

METHODS

The consecutive DBD or DCD donors with DUS/CEUS examinations before surgical procurement from February 2016 to June 2018 at our institution were included. The US and CEUS images of each donor liver were analyzed and the parameters were recorded.

RESULTS

Among the 67 eligible donor livers, 15 (22.4%) were discarded and 52 (77.6%) were used. The discarded livers showed prolonged SAT of hepatic artery (0.08s vs 0.06s, OR = 2.169, P = 0.008) on DUS, less cases with homogeneous enhancement (40.0% vs 73.1%, OR = 0.243, P = 0.028) on CEUS, more cases with decreased enhancement (53.3% vs 19.2%, OR = 4.800, P = 0.009), and less difference of the peak time between portal vein and liver parenchymal (0.5s vs 6.7s, OR = 0.917, P = 0.034). The multivariable analysis showed that donor liver with prolonged SAT of hepatic artery (OR = 7.304, 95% CI: 1.195-44.655, P = 0.031) and decreased enhancement (OR = 2.588, 95% CI: 1.234-5.426, P = 0.012) were independent factors of liver discarded.

CONCLUSIONS

DUS/CEUS could be applied as a promising predictive tool to screen high-risk liver donors. The prolonged SAT of hepatic artery on DUS and the decrease of liver donor in enhancement on CEUS, indicating hemodynamic changes in DBD and DCD donor livers, were risk factors of liver discarded.

Point of Care Ultrasonography for Objective Assessment of Heart Failure: Integration of Cardiac, Vascular, and Extravascular Determinants of Volume Status

BACKGROUND

Lingering congestion portends poor outcomes in patients with heart failure (HF) and is a key target in their management. Studies have shown that physical exam has low yield in this setting and conventional methods for more precise assessment and monitoring of volume status (e.g., body weight, natriuretic peptides, and chest radiography) have significant inherent shortcomings.

SUMMARY

Point of care ultrasonography (POCUS) is a noninvasive versatile bedside diagnostic tool that enhances the sensitivity of conventional physical examination to gauge congestion in these patients. It also aids in monitoring the efficacy of decongestive therapy and bears prognostic significance. In this narrative review, we discuss the role of focused sonographic assessment of the heart, venous system, and extravascular lung water/ascites (i.e., the pump, pipes, and the leaks) in objective assessment of fluid volume status. Key Messages: Since each of the discussed components of POCUS has its limitations, a combinational ultrasound evaluation guided by the main clinical features would be the key to reliable assessment and effective management of congestion in patients with HF.

Contrast-enhanced ultrasonography to evaluate risk factors for short-term and long-term outcomes after liver transplantation: A pilot prospective study

PURPOSE

To evaluate whether Doppler ultrasonography (DUS) and contrast-enhanced ultrasonography (CEUS) can identify liver donation after brain death (DBD) and cardiac death (DCD) with the risk of developing short-term primary graft dysfunction (PGD) or arterial and biliary complications within 1 year.

MATERIALS AND METHODS

Consecutive DBD and DCD donors who underwent DUS/CEUS examinations before surgical procurement from February 2016 to June 2018 at our institution were included. The US and CEUS images of each donor liver were analysed, and the parameters were recorded.

RESULTS

The mean time for US examination was 32 min (range, 20-59 min), and all donors tolerated the examination well. In terms of short-term outcomes, among the 52 eligible donor livers, 20 (38.5 %) of their recipients developed PGD. The multivariable analysis showed that decreased enhancement of donor livers on CEUS (OR = 15.976, 95 % CI: 1.652-154.628, P = 0.017) and high recipient model for end-stage liver disease (MELD) scores (OR = 1.050, 95 % CI: 1.004-1.099, P = 0.034) before liver transplantation (LT) were independent factors of PGD. In contrast, for long-term complications, among the 48 eligible donor livers, 16 (33.3 %) developed arterial or biliary complications within 1 year. The multivariable analysis did not show any independent factors of arterial or biliary complications within 1 year.

CONCLUSIONS

A decrease in enhancement on CEUS is an independent risk factor for poor short-term outcomes of LT. CEUS may be promising for predicting post-LT outcomes of critically ill donors effectively and safely by evaluating the haemodynamic changes in DBD and DCD donor livers.

Noninvasive imaging assessment of portal hypertension

Portal hypertension (PH) is a spectrum of complications of chronic liver disease (CLD) and cirrhosis, with manifestations including ascites, gastroesophageal varices, splenomegaly, hypersplenism, hepatic hydrothorax, hepatorenal syndrome, hepatopulmonary syndrome and portopulmonary hypertension. PH can vary in severity and is diagnosed via invasive hepatic venous pressure gradient measurement (HVPG), which is considered the reference standard. Accurate diagnosis of PH and assessment of severity are highly relevant as patients with clinically significant portal hypertension (CSPH) are at higher risk for developing acute variceal bleeding and mortality. In this review, we discuss current and upcoming noninvasive imaging methods for diagnosis and assessment of severity of PH.

Investigation of Thrombosis Volume, Anticoagulants, and Recurrence Factors in Portal Vein Thrombosis with Cirrhosis

This retrospective study investigated factors influencing the portal vein thrombosis (PVT) volume and recurrence in 52 cirrhosis patients with PVT from November 2008 to September 2018. All patients were treated with danaparoid sodium with or without additional antithrombin III. Blood platelet counts significantly correlated with the PVT volume (r² = 0.17; P < 0.01). Computed tomography confirmed recurrence as PVT aggravation was reported in 43 patients, with ≥50% PVT volume reduction following anticoagulation therapy. In 43 patients, recurrence significantly correlated with the pretreatment PVT volume (P = 0.019). Factors influencing recurrence included a Child-Pugh score >8 (P = 0.049) and fibrosis index ≤7.0 based on four factors (FIB-4) (P = 0.048). Moreover, the relationship between recurrence and correlating factors showed that 15 patients who received warfarin experienced recurrence more often when Child-Pugh scores were >8 (P = 0.023), regardless of maintenance treatment. For patients who did not receive warfarin, a PVT volume ≥3.0 mL significantly influenced recurrence (P = 0.039). Therefore, the platelet count influences the PVT volume. The pretreatment PVT volume correlated with recurrence after anticoagulation therapy. According to the Kaplan-Meier curve, risk factors for PVT recurrence after anticoagulation therapy included Child-Pugh scores >8 and FIB-4 ≤7.0. Therefore, the FIB-4 is a unique factor that shows trends opposing other liver function markers.

Portal vein flow velocity as a possible fast noninvasive screening tool for esophageal varices in cirrhotic patients

Background and Aim

Esophagogastroduodenoscopy (EGD) is the gold standard tool in both screening/diagnosis and management of varices in cirrhotic patients; however, its invasive nature may be uncomfortable to some patients, and in addition, it may be unavailable in some centers that cannot afford it. Therefore, to decrease the economic and physical burden on patients, multiple noninvasive clinical, laboratory, and radiological parameters are evaluated as triage screening predictors of varices before patients' referral to endoscopy. In this respect, we tried to evaluate the validity of portal vein velocity (PVV) as a noninvasive screening tool of esophageal varices (EV).

Methods

One hundred thirty‐five cirrhotic patients were consecutively enrolled in this cross‐sectional study. All patients were evaluated independently and blindly by EGD as the gold standard and then by Doppler ultrasound on portal vein (PV).

Results

Univariate regression showed significant coefficients for PVV, platelet (PLT), albumin, bilirubin, international normalized ratio (INR), portal vein diameter, and ascites; however, multivariable regression showed significant coefficients only for PVV, PLT, and albumin; (P = 0.000, 0.000, and 0.006, respectively). Area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, LR+, and LR− values were then calculated and validated using bootstrap analysis. PVV was more accurate than other evaluated parameters (AUROC: 0.927 and P = 0.000). The most accurate rule out cutoff value for PVV was ≥19 cm/s with the sensitivity of 97% and LR− of 0.05.

Conclusion

PVV may be useful as a noninvasive triage test for selection of the high‐risk cirrhotic patients who should be referred to and could benefit from EGD. We could highlight using PVV to rule out EV at a cutoff value ≥19 cm/s, reserving EGD only for patients with the PVV value <19 cm/s.

Recent developments in the field of vascular liver diseases

Knowledge in the field of vascular liver disease is continuously expanding. The present update will discuss recent data on i) the Abernethy malformation in adults; ii) portal vein thrombosis in cirrhosis; iii) advancing expertise in recanalization of the portal vein and iv) experience in using direct oral anticoagulants in the field of vascular liver disease.

Incidence, predictive factors and clinical significance of development of portal vein thrombosis in cirrhosis: A prospective study

BACKGROUND AND AIMS

The role of portal vein thrombosis (PVT) in the natural history of cirrhosis is controversial. There are few prospective studies validating risk factors for development of PVT. We analysed the incidence, factors associated with PVT development and its influence on cirrhosis decompensations and orthotopic liver transplant (OLT)-free survival.

METHODS

In this prospective observational study between January 2014 and March 2019, 445 consecutive patients with chronic liver disease were screened and finally 241 with cirrhosis included. Factors associated with PVT development and its influence on cirrhosis decompensations and OLT-free survival by time dependent covariate coding were analysed.

RESULTS

Majority of patients belonged to Child-Pugh class A 184 (76.3%) and the average MELD score was 10 ± 5. Previous cirrhosis decompensations occurred in 125 (52.1%), 63 (26.1%) were on NSBB and 59 (27.2%) had undergone banding for bleeding prophylaxis. Median follow-up was 29 (1-58) months. Cumulative incidence of PVT was 3.7% and 7.6% at 1 and 3 years. Previous decompensation of cirrhosis and low platelet counts but not NSBB independently predicted the development of PVT. During follow-up, 82/236 (34.7%) patients developed cirrhosis decompensations. OLT-free survival was 100% and 82.8% at 3 years, with and without PVT respectively. MELD score, but not PVT, independently predicted cirrhosis decompensations (HR 1.14; 95%CI:1.09-1.19) and OLT-free survival (HR 1.16;95%CI:1.11-1.21).

CONCLUSION

Previous decompensations of cirrhosis and thrombocytopenia predict PVT development in cirrhosis suggesting a pathophysiologic role for severity of portal hypertension. PVT development did not independently predict cirrhosis decompensations or lower OLT-free survival.

Elevated International Normalized Ratio: A Risk Factor for Portal Vein Thrombosis in Cirrhotic Patients

Background

Portal vein thrombosis (PVT) is a complication that is commonly seen in patients with cirrhosis and an entity that leads to increased mortality in patients who undergo liver transplantation. This study aims to establish a link between an elevated international normalized ratio (INR) and the presence of PVT in a cohort of cirrhotic patients.

Methods

We retrospectively reviewed the electronic medical records of all patients diagnosed with cirrhosis in SBH Health System from 2013 to 2018. Among these patients we extracted baseline demographic data, laboratory results, co-morbidities and the presence of PVT.

Results

In total there were 268 patients who met our inclusion criteria. Twenty-two patients had PVT, while 246 patients did not. Of the 22 patients with PVT there was a statistically significant increase in INR when compared to patients without PVT. There was also a statistically significant increase in total bilirubin, alkaline phosphatase and platelet count.

Conclusions

Elevated INR levels are associated with the presence of PVT in patients with cirrhosis. These findings suggest a hypercoagulable state and could assist clinicians in risk-stratifying patients when making the decision to initiate anti-coagulation therapy.

Evaluation of portal hypertension in the cirrhotic patient: hepatic vein pressure gradient and beyond

Portal hypertension (PH) is a major complication of liver cirrhosis, as it predisposes to the development of serious clinical manifestations such as ascites, hepatic encephalopathy and variceal bleeding. Till now, the measurement of hepatic vein pressure gradient (HVPG) is the gold standard method to ascertain the presence and significance of PH, as many studies have shown its correlation with the appearance of varices and the possibility of variceal bleeding. However, the invasiveness of this procedure makes it difficult to be used in daily clinical practice. Several noninvasive methods with adequate capability of evaluating liver fibrosis, including elastographic techniques, are currently used as alternatives to HVPG in order to assess the presence and the severity of PH. The aim of this paper is to express an overview of the literature about the actual role of HVPG and all available noninvasive tests on the prediction of development of PH complications, to highlight their advantages and their potential limitations, and to provide the latest trends on clinical practice.

The risk factors of portal vein thrombosis in patients with liver cirrhosis

This study was designed to identify and assess risk factors for portal vein thrombosis (PVT) in patients with cirrhosis. A total of 98 cirrhosis patients with PVT were identified and 101 cirrhosis patients without PVT were chosen as the control group in this retrospective study. Several variables were measured and the two groups PVT and non-PVT were compared statistically. PVT was identified in 98 patients (10%). Significant differences in hematocrit, international normalized ratio, albumin, bilirubin and glucose were determined between the groups (P<0.05). Out of the thrombophilic risk factors in the patients with PVT factor V Leiden was identified in 8.8%, prothrombin gene 6.6% and methylenetetrahydrofolate reductase 2.2%. There was no difference in survival time between groups (P>0.05).

Multiparametric ultrasound in liver diseases: an overview for the practising clinician

Ultrasound (US) is usually the first and most commonly used tool in the diagnostic algorithm for liver disease. It is widely available, non-invasive and offers a real-time assessment of the liver in several anatomic planes, using different US modalities such as greyscale imaging, Doppler, elastography and contrast-enhanced US. This multiparametric ultrasound (MPUS) provides more information of the examined structures and allows for a faster and more accurate diagnosis, usually at the point of care, thus reducing the requirement for some invasive and more expensive methods. Current data on the MPUS in hepatology are summarised in this review, mostly focused on its use for non-invasive staging of liver fibrosis, detection and classification of portal hypertension and oesophageal varices, prognosis in chronic liver diseases and characterisation of focal liver lesions (FLLs). Based on the available data, we propose practical algorithms for clinical use of MPUS in chronic liver disease and FLL.

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.

Decreased portal vein velocity is predictive of the development of portal vein thrombosis: A matched case-control study

BACKGROUND & AIMS

Portal vein thrombosis (PVT) in cirrhosis may lead to hepatic decompensation and increased mortality. We aimed to investigate if decreased portal vein (PV) velocity is associated with future PVT.

METHODS

Data on adult patients with cirrhosis and PVT between January 1, 2005 and July 30, 2015 were obtained. Cases with PVT were matched by age, gender and Model for End-stage Liver Disease (MELD) score to corresponding controls without PVT. Cox proportional hazards models, receiver operator curves and Kaplan Meier curves were constructed.

RESULTS

One hundred subjects (50 matched pairs) with mean age 53.8±13.1 y and MELD score 14.9±5.5 were included in our analysis. Sixty-four percent were male and 76% were Child-Turcotte-Pugh Class A or B. Baseline characteristics (prior to development of PVT) were similar, except for baseline PV velocity (16.9 cm/s, 95% CI 13.9-20.0 PVT vs 25.0, 95% CI 21.8-28.8 no PVT, P<.001). 30 PVT subjects had PV velocity <15 cm/s compared to five without PVT (P<.001). On adjusted multivariable analysis, PV velocity was the strongest independent risk factor predicting PVT development (HR 0.86, 95% CI 0.80-0.93). The predictive value for PVT development was greatest for flow <15 cm/s (c-statistic 0.77). PV velocity <15 cm/s had a highly significant association with future PVT (HR 6.00, 95% CI 2.20-16.40, P=<.001).

CONCLUSIONS

Decreased PV velocity is associated with increased risk of future PVT. Patients with cirrhosis and decreased PV velocity are a high-risk subgroup that warrants further investigation with prospective study.

Portal vein thrombosis in liver cirrhosis: incidence, management, and outcome

Background

Portal vein thrombosis (PVT) is a serious complication in liver cirrhosis with portal hypertension. We examined the treatment, recurrence and prognosis of PVT in cirrhotic patients.

Methods

The study subjects were all 90 cirrhotic patients with PVT treated with danaparoid sodium (DS) at our department between July 2007 and September 2016. The mean age was 68 years and mean Child-Pugh score was 7. All patients received 2500 U/day of DS for 2 weeks, and repeated in those who developed PVT recurrence after the initial therapy.

Results

Complete response was noted in 49% (n = 44), partial response (shrinkage ≥70%) in 33% (n = 30), and no change (shrinkage <70%) in 18% (n = 16) of the patients after the initial course of treatment. DS treatment neither caused adverse events, particularly bleeding or thrombocytopenia, nor induced significant changes in serum albumin, total bilirubin, prothrombin time, and residual liver function. Re-treatment was required in 44 patients who showed PVT recurrence and 61% of these responded to the treatment. The cumulative recurrence rates at 1 and 2 posttreatment years were 26 and 30%, respectively. The recurrence rates were significantly lower in patients with acute type, compared to the chronic type (p = 0.0141). The cumulative survival rates at 1 and 3 years after treatment (including maintenance therapy with warfarin) were 83 and 60%, respectively, and were significantly higher in patients with acute type than chronic type (p = 0.0053).

Conclusion

We can expect prognostic improvement of liver cirrhosis by warfarin following two-week DS therapy for the treatment of PVT in patients with liver cirrhosis safety and effectiveness. An early diagnosis of PVT along with the evaluation of the volume of PVT on CT and an early intervention would contribute to the higher efficacy of the treatment.

Wall shear stress in portal vein of cirrhotic patients with portal hypertension

AIM

To investigate wall shear stress (WSS) magnitude and distribution in cirrhotic patients with portal hypertension using computational fluid dynamics.

METHODS

Idealized portal vein (PV) system models were reconstructed with different angles of the PV-splenic vein (SV) and superior mesenteric vein (SMV)-SV. Patient-specific models were created according to enhanced computed tomography images. WSS was simulated by using a finite-element analyzer, regarding the blood as a Newtonian fluid and the vessel as a rigid wall. Analysis was carried out to compare the WSS in the portal hypertension group with that in healthy controls.

RESULTS

For the idealized models, WSS in the portal hypertension group (0-10 dyn/cm²) was significantly lower than that in the healthy controls (10-20 dyn/cm²), and low WSS area (0-1 dyn/cm²) only occurred in the left wall of the PV in the portal hypertension group. Different angles of PV-SV and SMV-SV had different effects on the magnitude and distribution of WSS, and low WSS area often occurred in smaller PV-SV angle and larger SMV-SV angle. In the patient-specific models, WSS in the cirrhotic patients with portal hypertension (10.13 ± 1.34 dyn/cm²) was also significantly lower than that in the healthy controls (P < 0.05). Low WSS area often occurred in the junction area of SV and SMV into the PV, in the area of the division of PV into left and right PV, and in the outer wall of the curving SV in the control group. In the cirrhotic patients with portal hypertension, the low WSS area extended to wider levels and the magnitude of WSS reached lower levels, thereby being more prone to disturbed flow occurrence.

CONCLUSION

Cirrhotic patients with portal hypertension show dramatic hemodynamic changes with lower WSS and greater potential for disturbed flow, representing a possible causative factor of PV thrombosis.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

Coagulopathy Before and After Liver Transplantation: From the Hepatic to the Systemic Circulatory Systems

The hemostatic environment in patients with cirrhosis is a delicate balance between prohemostatic and antihemostatic factors. There is a lack of effective laboratory measures of the hemostatic system in patients with cirrhosis. Many are predisposed to pulmonary embolus, deep vein thrombosis, and portal vein thrombosis in the pretransplantation setting. This pretransplantation hypercoagulable milieu seems to extend for at least several months post-transplantation. Patients with nonalcoholic fatty liver disease, inherited thrombophilia, portal hypertension in the absence of cirrhosis, and hepatocellular carcinoma often require individualized approach to anticoagulation. Early reports suggest a potential role for low-molecular-weight heparins and direct-acting anticoagulants.

Invasive and non-invasive assessment of portal hypertension

Portal hypertension is the central driver of complications in patients with chronic liver diseases and cirrhosis. The diagnosis of portal hypertension has important prognostic and clinical implications. In particular, screening for varices in patients with portal hypertension can effectively reduce the morbidity and mortality of variceal bleeding. In this article, we review the invasive and non-invasive methods to assess portal hypertension. Hepatic venous pressure gradient remains the gold standard to measure portal pressure but is invasive and seldom performed outside expert centers and research settings. In recent years, a number of non-invasive tests of fibrosis have shown good correlation with liver histology. They also show promise in identifying patients with portal hypertension and large varices. As a result, the latest Baveno VI consensus guidelines endorse the use of liver stiffness measurement by transient elastography and platelet count as initial assessment to select patients for varices screening. On the other hand, the performance of non-invasive tests in assessing the response to non-selective beta-blockers or transjugular intrahepatic portosystemic shunting is either suboptimal or unclear.

Reliability of Ultrasound Screening of Liver and Kidney Donors: A Retrospective Study

The reliability of abdominal ultrasound in screening liver and kidney donors was assessed by correlating ultrasound findings with the suitability of organs for transplantation as determined by direct examination of the organs. We evaluated 100 multiorgan donors (100 livers, 200 kidneys) during a 15-month period. Abdominal ultrasound showed the following results for liver and kidney, respectively: specificity, 95.6% and 98.9%; sensitivity, 62.5% and 66.6%; and accuracy, 93% and 97%. These results show that abdominal ultrasound is a valuable tool for determining suitability of organs for transplantation when the ultrasound findings are normal. When ultrasound findings are abnormal, further studies are necessary to determine the suitability of the organs for transplantation.

Contrast-enhanced ultrasonography could be a non-invasive method for differentiating none or mild from severe fibrosis in patients with biopsy proven non-alcoholic fatty liver disease

OBJECTIVE

The gold standard for diagnosing fibrosis stage in non-alcoholic fatty liver disease (NAFLD) is liver biopsy. The aim of this study was to determine whether contrast-enhanced ultrasonography (CEUS) with transit time measurements could be a non-invasive alternative for differentiating none or mild from severe fibrosis in NAFLD patients. Various serum markers and clinical variables were also evaluated.

MATERIALS AND METHODS

Fifty-eight patients with NAFLD underwent CEUS prior to liver biopsy. All patients were also evaluated according to the Göteborg University Cirrhosis Index (GUCI), the AST-Platelet Ratio Index (APRI), the NAFLD fibrosis score, and the FIB-4 and BARD score.

RESULTS

The hepatic vein arrival time (HV) was shorter in patients with severe fibrosis (25.9 ± 4.8 vs 29.5 ± 4.7 s, p = 0.023), and the difference between the hepatic and portal vein (ΔHV-PV) was shorter (2.3 ± 2.8 vs 6.4 ± 2.8 s, p < 0.0001) while the difference in arrival time between the portal vein and hepatic artery (ΔPV-HA) arrival time was significantly longer (6.0 ± 2.2 vs 3.6 ± 1.6 s, p < 0.0001). The area under receiver operating characteristics curve values for HV, ΔHV-PV and ΔPV-HA to separate none or mild from severe fibrosis was 0.71, 0.83 and 0.84, respectively. The corresponding figures for GUCI, APRI, NAFLD fibrosis score, FIB-4 and BARD score were 0.93, 0.92, 0.86, 0.90 and 0.77, respectively.

CONCLUSIONS

CEUS and non-invasive scoring systems could exclude severe fibrosis in NAFLD patients.

Liver and spleen stiffness and other noninvasive methods to assess portal hypertension in cirrhotic patients: a review of the literature

Portal hypertension (PH) is one of the most important causes of morbidity and mortality in patients with chronic liver disease. PH measurement is crucial to stage and predict the clinical outcome of liver cirrhosis. Measurement of hepatic vein pressure gradient is considered the gold standard for assessment of the degree of PH; however, it is an invasive method and has not been used widely. Thus, noninvasive methods have been proposed recently. We critically evaluated serum markers, abdominal ultrasonography, and particularly liver and spleen stiffness measurement, which represent the more promising methods to stage PH degree and to assess the presence/absence of esophageal varices (EV). A literature search was carried out on MEDLINE, EMBASE, Web of Science, and Scopus for articles and abstracts. The search terms used included 'liver cirrhosis', 'portal hypertension', 'liver stiffness', 'spleen stiffness', 'ultrasonography', and 'portal hypertension serum biomarker'. The articles cited were selected on the basis of their relevance to the objective of the review. The results of available studies indicate that individually, these methods have a mild accuracy in predicting the presence of EV, and thus they cannot substitute endoscopy to predict EV. When these tests were used in combination, their accuracy increased. In addition to the PH staging, several serum markers and spleen stiffness measurement can predict the clinical outcome of liver cirrhosis with a good accuracy, comparable to that of hepatic vein pressure gradient. In the future, noninvasive methods could be used to select patients requiring further investigations to identify the best tailored clinical management.

De-novo portal vein thrombosis in liver cirrhosis: risk factors and correlation with the Model for End-stage Liver Disease scoring system

BACKGROUND AND OBJECTIVES

Portal vein thrombosis (PVT) is a potential lethal complication in late liver cirrhosis. There is a lack of knowledge of the clinical features and risk factors of PVT. We aimed to investigate the clinical and radiological characteristics, and biochemical markers of cirrhotic patients to determine the high-risk individuals for PVT attending our center.

PATIENTS AND METHODS

Of 426 cirrhotic patients, only 120 consecutive patients were included. Clinical, biochemical, immunological, Model for End-stage Liver Disease (MELD) score, portal vein patency, and flow velocity were measured in all patients at baseline and every 6 months thereafter. Variables that could predict the development of PVT within 1 year were identified by multiple logistic regression.

RESULTS

Only 95 patients completed the study; PVT was found in 17 (17.9%) patients. PVT was observed mainly in the portal trunk, superior mesenteric vein, and splenic vein. Univariate analysis showed that diabetes mellitus, lower levels of hemoglobin, platelet counts, and portal vein flow velocity as well as increased MELD scores, platelet indices, portal vein diameter, and splenic thickness were associated with PVT patients than in non-PVT patients (all P<0.01).

CONCLUSION

The incidence of PVT was 17.9%. PVT occurred mainly in the portal vein trunk, superior mesenteric vein, and splenic vein. Diabetes mellitus, lower levels of hemoglobin, platelet count and portal vein flow velocity as well as increased MELD score, platelet indices, portal vein diameter, and splenic thickening were associated with PVT. Splenic thickening, marked reduced of mean portal flow velocity, and diabetes mellitus may be risk factors for PVT.

Quantification of hepatic blood flow using a high-resolution phase-contrast MRI sequence with compressed sensing acceleration

OBJECTIVE. The objective of our study was to evaluate the performance of a high-spatial-resolution 2D phase-contrast (PC) MRI technique accelerated with compressed sensing for portal vein (PV) and hepatic artery (HA) flow quantification in comparison with a standard PC MRI sequence. SUBJECTS AND METHODS. In this prospective study, two PC MRI sequences were compared, one with parallel imaging acceleration and low spatial resolution (generalized autocalibrating partial parallel acquisition [GRAPPA]) and one with compressed sensing acceleration and high spatial resolution (sparse). Seventy-six patients were assessed, including 37 patients with cirrhosis. Two observers evaluated PC image quality. Quantitative analyses yielded a mean velocity, flow, and vessel area for the PV and HA and an arterial fraction. The PC techniques were compared using the paired Wilcoxon test and Bland-Altman statistics. The sensitivity of the flow parameters to the severity of cirrhosis was also assessed. RESULTS. Vessel delineation was significantly improved using the PC sparse sequence (p < 0.034). For both in vitro and in vivo measurements, PC sparse yielded lower estimates for vessel area and flow, and larger differences between PC GRAPPA and PC sparse were observed in the HA. PV velocity and flow were significantly lower in patients with cirrhosis on both PC sparse (p < 0.001 and p = 0.042, respectively) and PC GRAPPA (p < 0.001 and p = 0.005, respectively). PV velocity correlated negatively with Child-Pugh class (r = -0.50, p < 0.001), whereas the arterial fraction measured with PC sparse was higher in patients with Child-Pugh class B or C disease than in those with Child-Pugh class A disease, with a trend toward significance (p = 0.055). CONCLUSION. A high-spatial-resolution highly accelerated compressed sensing technique (PC sparse) allows total hepatic blood flow measurements obtained in 1 breath-hold, provides improved delineation of the hepatic vessels compared with a standard PC MRI sequence (GRAPPA), and can potentially be used for the noninvasive assessment of liver cirrhosis.

Causes and consequences of portal vein thrombosis in 1,243 patients with cirrhosis: results of a longitudinal study

In cirrhosis, portal vein thrombosis (PVT) could be a cause or a consequence of the progression of liver disease. We analyzed data from a prospective trial of ultrasound screening for hepatocellular carcinoma in order to identify risk factors for and the impact of PVT in patients with cirrhosis. In all, 1,243 adults with cirrhosis without PVT were enrolled from 43 liver units in France and Belgium between June 2000 and March 2006. The mean follow-up was 47 months. Doppler ultrasonography was used to check the portal vein. Progression of liver disease was defined by the development of: ascites, hepatic encephalopathy, variceal bleeding, prothrombin <45%, serum bilirubin >45 μmol/L, albumin <28 g/L, and/or creatinine >115 μmol/L. G20210A prothrombin and factor V gene mutations were assessed in sera stored at three large centers. The 5-year cumulative incidence of PVT was 10.7%. PVT was mostly partial and varied over time. The development of PVT was independently associated with baseline esophageal varices (P = 0.01) and prothrombin time (P = 0.002), but not with disease progression before PVT, or prothrombotic mutations. Disease progression was independently associated with baseline age (hazard ratio [HR] 1.55; 95% confidence interval [CI]: 1.11-2.17), body mass index (HR 1.40; 95% CI: 1.01-1.95), prothrombin time (HR 0.79; 95% CI: 0.70-0.90), serum albumin (HR 0.97; 95% CI: 0.94-0.99), and esophageal varices (HR 1.70; 95% CI: 1.21-2.38) but not with the prior development of PVT (HR 1.32; 95% CI: 0.68-2.65).

CONCLUSION

In patients with cirrhosis, the development of PVT is associated with the severity of liver disease at baseline, but does not follow a recent progression of liver disease. There is no evidence that the development of PVT is responsible for further progression of liver disease.

Review article: portal vein obstruction--epidemiology, pathogenesis, natural history, prognosis and treatment

BACKGROUND

Portal vein obstruction may be due to portal vein thrombosis (PVT) or its sequale, the portal cavernoma. PVT is a common complication in liver cirrhosis, however, it may also occur as a primary vascular disorder, in absence of any liver disease.

AIM

To review the current knowledge on nomenclature, etiology, pathophysiology, clinical presentation, diagnostic workup and management of adult patients with obstruction in the portal vein, either as a primary vascular disease in adults, or as a complication of liver cirrhosis.

METHODS

A structured search in PubMed was performed using defined keywords (portal vein obstruction, extra-hepatic portal vein obstruction, PVT and portal cavernoma), including full text articles and abstracts in English language.

RESULTS

Several causes, operating both at local and systemic level, might play an important role in the pathogenesis of PVT. Frequently, more than one risk factor could be identified; however, occasionally no single factor is discernible. Diagnosis of portal vein obstruction depends on clinical presentation, imaging and laboratory investigations. Prompt treatment greatly affects the patient's outcome.

CONCLUSIONS

Portal vein obstruction occurring either due to thrombosis in the portal vein or due to the portal cavernoma, can contribute to significant morbidity and mortality in patients with or without cirrhosis. In recent years our understanding of etio-pathogenesis of portal vein obstruction has evolved tremendously, which has led to significant improvement in treatment outcomes. There are still areas where more studies are needed to better clarify the management issues of portal vein obstruction.

Novel insights into the development of portal vein thrombosis in cirrhosis patients

The prognostic impact of portal vein thrombosis (PVT) in liver cirrhosis remains controversial among studies, primarily because the risk stratification of PVT is often lacking. A definition of clinically significant PVT should be proposed and actively improved. Moreover, the risk factors for the development of PVT in liver cirrhosis should be fully recognized to screen and identify high-risk patients. Currently, well-recognized risk factors include a reduced portal vein flow velocity, a worse liver function, splenectomy, liver transplantation, and factor V Leiden and prothrombin G20210A mutations. Novel risk factors include an increased flow volume of portosystemic collateral vessel, thrombopoietin receptor agnonists, and non-selective beta-blockers. In contrast to the traditional perspectives, the abnormalities of procoagulant and anticoagulant factors may not contribute to the development of PVT in liver cirrhosis. Further studies should explore the role of other risk factors, such as antiphospholipid antibodies, methylenetetrahydrofolate reductase C677T gene mutation, hyperhomocysteinemia, and myeloproliferative neoplasms.

[Liver ultrasound: focal lesions and diffuse diseases]

Liver ultrasound is frequently used as a first-line technique for the detection and characterization of the most common liver lesions, especially those incidentally found focal liver lesions, and for monitoring of chronic liver diseases. Ultrasound is not only used in the Bmode, but also with Doppler and, more recently, contrast-enhanced ultrasound. It is mainly used in the diagnosis of diffuse liver diseases, such as steatosis or cirrhosis. This article presents a practical approach for diagnosis workup, in which the different characteristics of the main focal liver lesions and diffuse liver diseases are reviewed.

Invasive and non-invasive techniques for detecting portal hypertension and predicting variceal bleeding in cirrhosis: a review

Portal hypertension is a severe syndrome that may derive from pre-sinusoidal, sinusoidal, and post-sinusoidal causes. As a consequence, several complications (i.e. ascites, oesophageal varices) may develop. In sinusoidal portal hypertension, hepatic venous pressure gradient (HVPG) is a reliable method for defining the grade of portal pressure, establishing the effectiveness of the treatment, and predicting the occurrence of complications; however, some questions exist regarding its ability to discriminate bleeding from non-bleeding varices in cirrhotic patients. Other imaging techniques (transient elastography, endoscopy, endosonography, and duplex Doppler sonography) for assessing causes and complications of portal hypertensive syndrome are available and may be valuable for the management of these patients. In this review, we evaluate invasive and non-invasive techniques currently employed to obtain a clinical prediction of deadly complications, such as variceal bleeding in patients affected by sinusoidal portal hypertension, in order to create a diagnostic algorithm to manage them. Again, HVPG appears to be the reference standard to evaluate portal hypertension and monitor the response to treatment, but its ability to predict several complications and support management decisions might be further improved through the diagnostic combination with other imaging techniques.