Measurement of hepatic vein pressure gradient in children with chronic liver diseases

Portal vein pressure and flow modulation in pediatric liver transplantation

Liver transplantation (LT) has been indicated for smaller and more clinically severe patients in recent years. Small biliary atresia (BA) patients often show portal hypoplasia and sclerotic portal vein (PV), which may make PV reconstruction more difficult during the operation. Among PV complications, intraoperative PV thrombosis can be considered a disaster, and it is important to prevent this catastrophic event by the precise assessment of the PV structure and PVF using radiological imaging before and during LT. However, there are no objective parameters to indicate whether sufficient PVF can be obtained. PV pressure (PVP) and PV flow (PVF) have mainly been studied in adult living donor LT, for the purpose of preventing small-for-size syndrome, and PVP has been considered an objective parameter of graft inflow modulation (GIM). In the setting of pediatric LT, GIM is mainly performed to prevent hypoperfusion, and it must be performed before graft implantation. GIM to maximize the PVF of pediatric patients with potentially low PVF in LT consists of the interruption of collateral vessels, the assessment of the usability of the native PV, and technical modifications in PV reconstruction. Reliable objective parameters that represent sufficient PVF before graft implantation are desired. Our recent study proposed that a PVP of ≥25 mmHg before graft implantation can be considered an objective parameter to obtain sufficient PVF (cutoff value: 50 mL/min/100 g of graft weight). Further investigation is needed to determine the best strategy for successful PV reconstruction in pediatric LT.

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Optimal Treatment for Patients With Cavernous Transformation of the Portal Vein

Cavernous transformation of the portal vein (CTPV) is a sequela of extrahepatic and/or intrahepatic portal vein obstruction caused by a combination of local and risk factors. It was ever taken as a relatively rare disease due to its scant literature, which was mainly based on clinical series and case reports. CTPV often manifests as gastroesophageal variceal bleeding, splenomegaly, and portal biliopathy after the long-term insidious presentation. It is unable for CTPV to be recanalized with anticoagulation because it is a complete obstruction of the mesentericoportal axis. Endoscopic therapy is mainly used for temporary hemostasis in acute variceal bleeding. Meso-Rex shunting characterized by portal-flow-preserving shunts has been widely performed in children with CTPV. The multitude of complications associated with CTPV in adults can be effectively addressed by various interventional vascular therapies. With the ubiquity of radiological examinations, optimal treatment for patients with CTPV becomes important. Multivisceral transplantation, such as liver-small intestinal transplantation, may be lifesaving and should be considered for patients with diffuse mesenteric venous thrombosis.

Operational Definitions for Chronic Liver Disease Manifestations and Recurring Clinical Events in Biliary Atresia

BACKGROUND

The disease course of biliary atresia (BA) may be complicated by development of chronic liver disease (CLD) manifestations (eg, ascites) and recurring clinical events (eg, cholangitis). Most pediatric CLD-manifestations/events lack standardized operational definitions, leading to inconsistent identification in clinical research. This study aimed to develop operational research definitions of CLD-manifestations/events in BA for application in retrospective analysis.

METHODS

Operational definitions of CLD-manifestations/events were developed by literature review and revised by a panel of experienced pediatric hepatologists. Definitions were applied to a single-center review of infants with BA post-Kasai. Manifestations/events were captured until last clinical visit with native liver (SNL), liver transplantation (LT), or death. Native liver survival and event-free survival were estimated by Kaplan-Meier method. Cluster analysis was performed to identify similar patterns of manifestation/event development.

RESULTS

Of 65 infants with BA post-Kasai (2006-18; median Kasai 56.8 days; 65% girls), 29 underwent LT (median 12.9 months) and 4 died without LT (median 6.9 months). Seventy-six percent of CLD-manifestations/events presented within the first year. Presence of definite clinically evident portal hypertension, thrombocytopenia, and dCE ascites were associated with poor transplant-free survival (P < 0.01). Similar pattern developments of CLD-manifestations/events identified 3 outcome groups: poor outcomes (87.8% LT/death), SNL with manifestations/events, and SNL with few/no events.

CONCLUSIONS

Operational definitions can provide a timely description of the disease course progression in infants with BA. Research definitions may provide better consistency in future pediatric CLD studies. Furthermore, definitions may serve as endpoints in therapeutic trials or used as variables for disease pattern identification in potential multicenter studies.

Novel imaging-based approaches for predicting the hepatic venous pressure gradient in a porcine model of liver cirrhosis and portal hypertension

AIMS

Hepatic venous pressure gradient (HVPG) is critical for staging and prognosis prediction of portal hypertension (PH). However, HVPG measurement has limitations (e.g., invasiveness). This study examined the value of non-invasive, imaging-based approaches including magnetic resonance elastography (MRE) and intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) for the prediction of HVPG in a porcine model of liver cirrhosis and PH.

MAIN METHODS

Male Bama miniature pigs were used to establish a porcine model of liver cirrhosis and PH induced by embolization. They were randomly assigned to an experimental group (n = 12) and control group (n = 3). HVPG was examined before and after transjugular intrahepatic portosystemic shunt (TIPS). MRE and IVIM-DWI were performed to obtain quantitative parameters including liver stiffness (LS) in MRE, tissue diffusivity (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) in IVIM-DWI. The correlation between HVPG and the parameters was assessed.

KEY FINDINGS

LS values were significantly greater in the experimental group, while f values were significantly decreased at 4, 8, and 12 weeks after embolization compared to the control group. Furthermore, HVPG was significantly lower immediately after versus before TIPS. In parallel, LS and f values showed significant alterations after TIPS, and these changes were consistent with a reduction in HVPG. Spearman analysis revealed a significant correlation between the parameters (LS and f) and HVPG. The equation was eventually generated for prediction of HVPG.

SIGNIFICANCE

The findings show a good correlation between HVPG and the quantitative parameters; thus, imaging-based techniques have potential as non-invasive methods for predicting HVPG.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Role of noninvasive tools for prediction of clinically evident portal hypertension in children

BACKGROUND

Noninvasive tools (NITs) for predicting varices in children with portal hypertension (PHTN) are infrequently used.

METHODS

Eighty-five consecutive, treatment-naïve children with PHTN and 97 controls were enrolled study from July 2017 to November 2018. Each case was evaluated by esophagogastroduodenoscopy (EGD) and various NITs: platelet spleen size Z (PSZ), clinical prediction rule (CPR), King's variceal prediction rule (KVaPS), Splenic stiffness (SSM) and liver stiffness measurement (LSM) by point shear wave elastrography (pSWE).

RESULTS

Had PHTN due to extra hepatic portal vein obstruction (EHPVO) and 70% due to cirrhosis [chronic liver disease (CLD)]. Sixty-five percent of PHTN cases had varices. Children with varices had lower platelet counts, lower albumin and larger spleens. SSM and LSM were significantly higher in cases as compared with controls. SSM was significantly higher in cases with varices than those without. SSM and LSM, at cutoffs of 3.8 and 3.2 kPa, respectively, discriminated PHTN cases from controls with an area under the curve (AUROC) of 0.67 (0.59-0.74). Both SSM and LSM predicted varices in CLD, but in EHPVO, only SSM predicted varices. SSM of 5.2 and 12.8 kPa, in CLD and EHPVO subgroups, respectively, had AUROC of 0.73 and 0.94 for variceal prediction. Blood-based NITs performed better in the CLD subgroup: aspartate aminotransferase platelet ratio index, CPR and KVPS predicted severity of PHTN with AUROC of 0.81, 0.92 and 0.93, respectively.

CONCLUSIONS

Blood-based NITs outperform elastography for prediction of PHTN/varices in children with CLD. SSM by pSWE is a better predictor of varices than LSM, especially in the EHPVO subgroup.

Clinically Evident Portal Hypertension: An Operational Research Definition for Future Investigations in the Pediatric Population

Portal hypertension (PHT) is a major cause of morbidity and mortality in pediatric liver diseases. Thus, research into causes and disease modifiers in PHT in these conditions is vitally important. PHT is rarely directly or indirectly measured in the assessment of children with chronic liver disease. A straightforward, reproducible definition of PHT could be invaluable for consistently identifying patients with PHT and for grouping these patients according to their risk of complications from their disease. We propose the term Clinically Evident Portal Hypertension (CEPH) to denote clinical findings that demonstrate evidence of elevated portal pressure. When CEPH criteria are met, PHT is highly likely to be present, although it is likely that PHT exists for variable periods of time before meeting CEPH criteria. Use of this research definition of CEPH will allow for consistent identification of these patients by clinicians in nearly any clinical setting and serve as a clinical milepost that may dictate future prognosis in pediatric patients with cirrhosis.

Hepatic Venous Pressure Gradient Measurements in Children: Correlation With Hepatic Histology and Clinical Indicators of Portal Hypertension

OBJECTIVES

In adults, elevated hepatic venous pressure gradients (HVPGs) are correlated with the degree of liver fibrosis on histopathology and predict worse outcomes including variceal bleeding and death. We aimed to examine the association between HVPG measurements, histopathologic findings, and clinical indicators of portal hypertension in children.

METHODS

Utilizing retrospective data from 2 pediatric centers between 2006 and 2015, we identified children who underwent simultaneous HVPG measurement and transjugular liver biopsy. Medical charts were reviewed for histopathology, imaging, endoscopic, and clinical data.

RESULTS

Forty-one children (median age 11 years) were included in the analysis with diagnoses of acute hepatitis (n = 15), chronic liver disease (n = 12), hepatic noncirrhotic portal hypertension (n = 4), acute liver failure (n = 3), and nonhepatic causes of portal hypertension (n = 7). Elevated mean HVPG measurements were found in children with acute liver failure (10 mmHg, range 4-12) and chronic liver disease (7 mmHg, range 1-12). HVPG measurements did not correlate with the histological severity of fibrosis (ρ = 0.23, P = 0.14) or portal inflammation (ρ = 0.24, P = 0.29), and no difference was found in HVPG when comparing children with and without a history of variceal bleeding (P = 0.43).

CONCLUSIONS

HVPG measurements do not correlate significantly with the degree of hepatic fibrosis on biopsy. Furthermore, HVPG measurements are not associated with the presence of varices or history of variceal bleeding, suggesting the possibility of intrahepatic shunting in children with advanced liver disease. Therefore, unlike in adults, HVPG measurements may not accurately predict children who are at risk of complications from portal hypertension.

Liver Stiffness Measured by Shear-wave Elastography for Evaluating Intrahepatic Portal Hypertension in Children

OBJECTIVES

The aim of the study was to correlate liver stiffness (LS) and hepatic venous-pressure gradient (HVPG) and to evaluate the diagnostic performance of shear-wave elastography (SWE) for predicting clinically significant portal hypertension in children with suspected liver diseases, in consideration of the reliability criteria.

METHODS

We identified 33 SWEs from 32 children who underwent HVPG measurement within 2 weeks between June 2012 and October 2015. The correlation between LS and HVPG was assessed. The diagnostic performance for predicting clinically significant portal hypertension (HVPG ≥ 10 mmHg) was assessed using the receiver-operating characteristic curve. Reliable measurement was evaluated based on the coefficient of variation (CV).

RESULTS

LS was significantly correlated with HVPG (r = 0.742, P < 0.001). The area under the receiver-operating characteristic curve for predicting clinically significant portal hypertension was 0.914, and the best cutoff value of 18.4 kPa showed sensitivity of 87.5% and specificity of 84.0%. LS measurements having CV ≤ 0.2 were significantly correlated with HVPG (r = 0.774, P < .001), whereas those having CV > 0.2 did not show a significant correlation with HVPG (r = 0.598, P = 0.089).

CONCLUSIONS

SWE had excellent diagnostic performance for predicting clinically significant portal hypertension in children with suspected liver diseases. LS measurements having CV ≤ 0.2 may possibly be used as a reliability criterion in SWE measurement.

A conceptual and practical approach to haemostasis in paediatric liver disease

Children with liver disease can develop severe bleeding episodes and thrombosis. Liver failure usually results in decreased levels of procoagulant and anticoagulant factors. Additional risk factors, including changes in vascular flow and endothelial function, are of importance for the development of bleeding or thrombosis in individual vascular beds. Detailed studies of haemostatic disturbances in the setting of paediatric liver disease are sparse and extrapolation from adult studies is common. The spectrum of liver diseases and the haemostatic system differs between children and adults. Specific paediatric liver diseases are reported to have more distinctive effects on haemostasis and the risk of bleeding and/or thrombosis.

CONCLUSION

we propose a model regarding haemostasis in paediatric liver disease, taking into account a number of specific variables and mechanisms, as well as the type of liver disease, which will provide a framework for clinical decision-making in these complex patients.

Primary prophylaxis of variceal bleeding in children and the role of MesoRex Bypass: Summary of the Baveno VI Pediatric Satellite Symposium

Approaches to the management of portal hypertension and variceal hemorrhage in pediatrics remain controversial, in large part because they are not well informed by rigorous clinical studies. Fundamental biological and clinical differences preclude automatic application of approaches used for adults to children. On April 11-12, 2015, experts in the field convened at the first Baveno Pediatric Satellite Meeting to discuss and explore current available evidence regarding indications for MesoRex bypass (MRB) in extrahepatic portal vein obstruction and the role of primary prophylaxis of variceal hemorrhage in children. Consensus was reached regarding MRB. The vast majority of children with extrahepatic portal vein obstruction will experience complications that can be prevented by successful MRB surgery. Therefore, children with extrahepatic portal vein obstruction should be offered MRB for primary and secondary prophylaxis of variceal bleeding and other complications, if appropriate surgical expertise is available, if preoperative and intraoperative evaluation demonstrates favorable anatomy, and if appropriate multidisciplinary care is available for postoperative evaluation and management of shunt thrombosis or stenosis. In contrast, consensus was not achieved regarding primary prophylaxis of varices. Although variceal hemorrhage is a concerning complication of portal hypertension in children, the first bleed appears to be only rarely fatal and the associated morbidity has not been well characterized.

CONCLUSION

There are few pediatric data to indicate the efficacy and safety of pharmacologic or endoscopic therapies as primary prophylaxis or that prevention of a sentinel variceal bleed will ultimately improve survival; therefore, no recommendation for primary prophylaxis with endoscopic variceal ligation, sclerotherapy, or nonspecific beta-blockade in children was proposed.

Advances in the management of childhood portal hypertension

Portal hypertension is one of the most serious complications of childhood liver disease, and variceal bleeding is the most feared complication. Most portal hypertension results from cirrhosis but extra hepatic portal vein obstruction is the single commonest cause. Upper gastrointestinal endoscopy endoscopy remains necessary to diagnose gastro-esophageal varices. Families of children with portal hypertension should be provided with written instructions in case of gastrointestinal bleeding. Children with large varices should be considered for primary prophylaxis on a case-by-case basis. The preferred method is variceal band ligation. Children with acute bleeding should be admitted to hospital and treated with antibiotics and pharmacotherapy before urgent therapeutic endoscopy. All children who have bled should then receive secondary prophylaxis. The preferred method is variceal band ligation and as yet there is little evidence to support the use of β-blockers. Children with extrahepatic portal vein obstruction should be assessed for suitability of mesoportal bypass.

Cirrhosis in children and adolescents: An overview

Several conditions, especially chronic liver diseases, can lead to cirrhosis in children and adolescents. Most cases in clinical practice are caused by similar etiologies. In infants, cirrhosis is most often caused by biliary atresia and genetic-metabolic diseases, while in older children, it tends to result from autoimmune hepatitis, Wilson's disease, alpha-1-antitrypsin deficiency and primary sclerosing cholangitis. The symptoms of cirrhosis in children and adolescents are similar to those of adults. However, in pediatric patients, the first sign of cirrhosis is often poor weight gain. The complications of pediatric cirrhosis are similar to those observed in adult patients, and include gastrointestinal bleeding caused by gastroesophageal varices, ascites and spontaneous bacterial peritonitis. In pediatric patients, special attention should be paid to the nutritional alterations caused by cirrhosis, since children and adolescents have higher nutritional requirements for growth and development. Children and adolescents with chronic cholestasis are at risk for several nutritional deficiencies. Malnutrition can have severe consequences for both pre- and post-liver transplant patients. The treatment of cirrhosis-induced portal hypertension in children and adolescents is mostly based on methods developed for adults. The present article will review the diagnostic and differential diagnostic aspects of end-stage liver disease in children, as well as the major treatment options for this condition.

Intestinal failure-associated liver disease: a position paper of the ESPGHAN Working Group of Intestinal Failure and Intestinal Transplantation

Intestinal failure-associated liver disease is the most prevalent complication affecting children with intestinal failure receiving long-term parenteral nutrition. This paper reviews the definition, diagnostic criteria, pathogenesis, and risk factors. The authors discuss the role of enteral nutrition, parenteral nutrition, and its components, especially lipid emulsions. The authors also discuss the surgical treatment, including intestinal transplantation, its indications, technique, and results, and emphasise the importance of specialised intestinal failure centres.

Impact of deep sedation on the accuracy of hepatic and portal venous pressure measurements in patients with cirrhosis

BACKGROUND & AIMS

Measurement of the hepatic venous pressure gradient (HVPG) offers valuable prognostic information in patients with cirrhosis. In specific circumstances, (children, agitated patients, TIPS placement) deep sedation is required. This study aims to assess the impact of deep sedation on the accuracy of hepatic/portal pressure measurements.

METHODS

Forty-four patients were included. Measurements of baseline HVPG (n = 30), HVPG response to i.v. propranolol (n = 11), portal pressure gradient (PPG) after TIPS (n = 27) and of cardio-pulmonary pressures (n = 25) were obtained in awake conditions and under deep sedation with propofol and remifentanil.

RESULTS

During deep sedation, a marked oscillation within respiratory cycle was observed in abdominal pressures. End-expiratory sedated HVPG showed a better agreement with awake HVPG (intra-class correlation coefficient - ICC 0.864) than end-inspiratory HVPG (ICC 0.796). However, in almost half of the patients both values differed by more than 10%. Accuracy was not improved by using mean HVPG along the respiratory cycle. Similarly, changes in HVPG caused by propranolol while under sedation had a poor agreement to those obtained in awake conditions. Indeed, about a half of patients were misclassified according to the 10% HVPG reduction target. After TIPS, PPG values obtained under sedation were significantly different to awake PPG, usually underestimating the awake value. The systemic hemodynamic changes induced by sedation were not associated to a greater variability of PPG/HVPG measurements.

CONCLUSION

Deep sedation with propofol and remifentanil adds substantial variability and uncertainty to HVPG/PPG measurements. This must be considered when using these values to estimate prognosis, or targeting HVPG/PPG reductions.

Measurement of hepatic venous pressure gradient is feasible and safe in children

BACKGROUND AND OBJECTIVES

Hepatic venous pressure gradient (HVPG) is an indirect measure of portal venous pressure in cirrhosis, which is valid in cirrhotic adults for evaluating the severity of portal hypertension, predicting outcomes, and guiding therapeutic decisions. Published data on the measurement of HVPG in children are sparse. The aim of the present study was to determine the feasibility and safety of undertaking HVPG measurements in children.

METHODS

Children who underwent HVPG measurements between 2000 and 2011 were identified from our interventional radiology database. Medical charts were reviewed for clinical, procedural, and outcome data.

RESULTS

A total of 49 patients (25 boys, mean age 8.2 ± 5.6 years) underwent 52 HVPG measurements. Diagnoses included cirrhosis (n = 7), acute liver failure (n = 15), postliver transplant (n = 6), postbone marrow transplant (n = 9), vascular anomalies (n = 3), and others (n = 9). There were no complications related to HVPG measurement. HVPG values ranged between 0 and 28 mmHg, median 9.0 (range 0-28) mmHg, and were elevated >6 mmHg in 30 patients.

CONCLUSIONS

HVPG measurement is feasible and safe in children with severe liver disease. The clinical use of HVPG measurements in managing children with portal hypertension or with acute liver diseases must now be determined.

Recent trends in the endoscopic management of variceal bleeding in children

Variceal bleeding results in significant morbidity and mortality in both children and adults. The guidelines for the management of variceal bleeding are well established in adults but not in children as there have been insufficient pediatric studies of this disorder. In addition, the adult guidelines for treatment of variceal bleeding cannot be applied directly to children as the etiology and natural course of this disease differs between children and adults. Examples of recommended treatments in children include endoscopic variceal ligation as secondary prophylaxis for biliary atresia whereas a meso-Rex shunt operation for extrahepatic portal vein obstruction. In this review, we discuss prophylaxis options and some technical aspects of endoscopic management for variceal bleeding in children.

Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children

INTRODUCTION

Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment.

AIM AND METHODS

To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations.

RESULTS

Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience.

CONCLUSIONS

Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis.

Portal hypertension in children and young adults with biliary atresia

OBJECTIVE

Biliary atresia (BA) frequently results in portal hypertension (PHT), complications of which lead to significant morbidity and mortality. The Childhood Liver Disease Research and Education Network was used to perform a cross-sectional multicentered analysis of PHT in children with BA.

METHODS

Subjects with BA receiving medical management at a Childhood Liver Disease Research and Education Network site were enrolled. A priori, clinically evident PHT was defined as "definite" when there was either history of a complication of PHT or clinical findings consistent with PHT (both splenomegaly and thrombocytopenia). PHT was denoted as "possible" if one of the findings was present in the absence of a complication, whereas PHT was "absent" if none of the criteria were met.

RESULTS

A total of 163 subjects were enrolled between May 2006 and December 2009. At baseline, definite PHT was present in 49%, possible in 17%, and absent in 34% of subjects. Demographics, growth, and anthropometrics were similar amongst the 3 PHT categories. Alanine aminotransferase, γ-glutamyl transpeptidase, and sodium levels were similar, whereas there were significant differences in aspartate aminotransferase (AST), AST/alanine aminotransferase, albumin, total bilirubin, prothrombin time, white blood cell count, platelet count, and AST/platelet count between definite and absent PHT. Thirty-four percent of those with definite PHT had either prothrombin time >15 seconds or albumin <3 g/dL.

CONCLUSIONS

Clinically definable PHT is present in two-thirds of North American long-term BA survivors with their native livers. The presence of PHT is associated with measures of hepatic injury and dysfunction, although in this selected cohort, the degree of hepatic dysfunction is relatively mild and growth is preserved.

Comparison of hepatic venous pressure gradient and two models of end-stage liver disease for predicting the survival in patients with decompensated liver cirrhosis

GOALS

We evaluated the efficacy of initial and follow-up hepatic venous pressure gradient (HVPG), models of end-stage liver disease (MELD), and MELD-Na for predicting the survival of patients with decompensated liver cirrhosis (LC).

BACKGROUND

MELD with/without Na score and HVPG have been important predictors of mortality in patients with LC.

STUDY

Between January 2006 and 2011, a total of 57 patients with decompensated LC, all of whom underwent >2 HVPG measurements for the confirmation of propranolol dosing, were enrolled. MELD and MELD-Na scores were calculated on the day of HVPG measurement. The prognostic accuracy of the initial and follow-up HVPG, MELD, and MELD-Na were analyzed, and independent factors for mortality were evaluated.

RESULTS

Ten patients (17.5%) died from LC. Initial HVPG (0.883), initial MELD-Na (0.877), follow-up HVPG (0.829), and follow-up MELD-Na (0.802) showed good area under the receiver operating characteristic curve scores in predicting 1-year mortality. In predicting 2-year mortality, only follow-up HVPG (0.821, cut-off value 18 mm Hg) showed good score. Overall area under the receiver operating characteristic curves (initial and follow-up) were 0.843 and 0.864 in HVPG, 0.721 and 0.674 in MELD, and 0.762 and 0.715 in MELD-Na, respectively. In the Cox regression analysis, only follow-up HVPG (P=0.02; odds ratio, 1.11) was associated with mortality.

CONCLUSIONS

The efficacy of HVPG for predicting mortality is excellent compared with that of MELD or MELD-Na. Therefore, aside from the confirmation of adequate propranolol dosing, HVPG may be needed for predicting the survival of patients with decompensated LC.

Portal hypertension in children: expert pediatric opinion on the report of the Baveno v Consensus Workshop on Methodology of Diagnosis and Therapy in Portal Hypertension

Complications of portal hypertension in children lead to significant morbidity and are a leading indication for consideration of liver transplantation. Approaches to the management of sequelae of portal hypertension are well described for adults and evidence-based approaches have been summarized in numerous meta-analyses and conferences. In contrast, there is a paucity of data to guide the management of complications of portal hypertension in children. An international panel of experts was convened on April 8, 2011 at The Children's Hospital of Pittsburgh of UPMC to review and adapt the recent report of the Baveno V Consensus Workshop on the Methodology of Diagnosis and Therapy in Portal Hypertension to the care of children. The opinions of that expert panel are reported.

Portal venous pressure in biliary atresia

Biliary atresia (BA) is characterized by a variable degree of fibrosis within the liver, causing portal hypertension sometimes evident at the time of presentation.

AIM

The aims of this study are to measure portal venous pressure (PVP) at time of Kasai portoenterostomy (KP) and to investigate the value of surrogate indices.

METHODS

At the time of KP and before any liver manipulation, an attempt was made to recanalize the umbilical vein, allowing a catheter to be sited. Preoperative noninvasive variables included maximum splenic diameter (on ultrasound); platelet count, aspartate aminotransferase, and bilirubin; and the aspartate aminotransferase/platelet index ratio (APRi). Clearance of jaundice was defined as achieving a bilirubin of less than 20 μmol/L. Data are quoted as median (range). Nonparametric statistical tests were used, and P < .05 was regarded as significant.

RESULTS

Portal venous pressure measurements were available in 61 infants, who underwent a KP during the period February 2007 to October 2010. Median age at KP was 52 (19-151) days. Median PVP was 9 (3-26) mm Hg and was significantly lower in those with isolated (n = 47) BA vs cytomegalovirus-associated BA (n = 6) (8 vs 17 mm Hg; P = .02). Overall, PVP correlated with spleen size (r(s) = 0.38; P < .0001), APRi (r(s) = 0.5; P < .0001), bilirubin (r(s) = 0.38; P = .001), and age at KP (r(s) = 0.33; P = .0004). Thirty-three infants (56%) cleared their jaundice (to <20 μmol/L). There was no significant difference in median PVP (7 vs 9.5 mm Hg; P = .1) between these groups. To date, 6 children have undergone endoscopy, with 2 requiring intervention for significant varices. Neither infant at time of KP had elevated PVP (3 and 9 mm Hg).

CONCLUSIONS

Portal venous pressure is a key variable in the assessment of the BA liver, and differences can be shown depending on underlying cause (eg, cytomegalovirus status). Furthermore, it has modest correlation with noninvasive indices (eg, spleen size and APRi) but appears of limited use when used as prognostic index of outcome and indeed in the later development of varices.