Risk of esophageal variceal bleeding based on endoscopic ultrasound evaluation of the sum of esophageal variceal cross-sectional surface area

Endohepatology: The endoscopic armamentarium in the hand of the hepatologist

ABSTRACT

Recent advances in the field of hepatology include new and effective treatments for viral hepatitis. Further effort is now being directed to other disease entities, such as non-alcoholic fatty liver disease, with an increased need for assessment of liver function and histology. In fact, with the evolving nomenclature of fat-associated liver disease and the emergence of the term "metabolic-associated fatty liver disease" (MAFLD), new diagnostic challenges have emerged as patients with histologic absence of steatosis can still be classified under the umbrella of MAFLD. Currently, there is a growing number of endoscopic procedures that are pertinent to patients with liver disease. Indeed, interventional radiologists mostly perform interventional procedures such as percutaneous and intravascular procedures, whereas endoscopists focus on screening for and treatment of esophageal and gastric varices. EUS has proven to be of value in many areas within the realm of hepatology, including liver biopsy, assessment of liver fibrosis, measurement of portal pressure, managing variceal bleeding, and EUS-guided paracentesis. In this review article, we will address the endoscopic applications that are used to manage patients with chronic liver disease.

Assessing the Predictive Factors for Bleeding in Esophageal Variceal Disease: A Systematic Review

Esophageal varices, dilated submucosal distal esophageal veins, are a common source of upper gastrointestinal bleeding in patients with portal hypertension. This review aims to comprehensively assess predictive factors for both the first occurrence and subsequent risk of esophageal variceal bleeding. A systematic search was conducted in PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online) and Cochrane databases. A total of 33 studies were selected using rigorous inclusion and exclusion criteria. The risk of bias was assessed using the Newcastle-Ottawa Scale. Several predictive factors were identified for esophageal variceal bleeding, including the Child-Pugh score, Fibrosis Index, specific endoscopic findings, ultrasound parameters, portal vein diameter, presence and size of collaterals, CT scan findings, ascites, platelet counts, coagulation parameters, albumin levels, Von Willebrand Factor, bilirubin levels, diabetes mellitus, and the use of b-blocking agents in primary prophylaxis. The findings of this systematic review shed light on multiple potential predictive factors for esophageal variceal bleeding. Endoscopic findings were found to be reliable predictors. Additionally, ultrasound parameters showed associations with bleeding risk. This systematic review identifies multiple potential predictive factors for esophageal variceal bleeding in patients with portal hypertension. While certain factors exhibit strong predictive capabilities, further research is needed to refine and validate these findings, considering potential limitations and biases. This study serves as a critical resource for bridging knowledge gaps in this field.

Endoscopic ultrasound-guided vascular interventions: An expanding paradigm

Endoscopic ultrasound (EUS) has expanded its arena from a mere diagnostic modality to an essential therapeutic tool in managing gastrointestinal (GI) diseases. The proximity of the GI tract to the vascular structures in the mediastinum and the abdomen has facilitated the growth of EUS in the field of vascular interventions. EUS provides important clinical and anatomical information related to the vessels' size, appearance and location. Its excellent spatial resolution, use of colour doppler with or without contrast enhancement and ability to provide images “real-time” helps in precision while intervening vascular structures. Additionally, structures such as venous collaterals or varices can be dealt with optimally using EUS. EUS-guided vascular therapy with coil and glue combination has revolutionized the management of portal hypertension. It also helps to avoid radiation exposure in addition to being minimally invasive. These advantages have led EUS to become an upcoming modality to complement traditional interventional radiology in the field of vascular interventions. EUS-guided portal vein (PV) access and therapy is a new kid on the block. EUS-guided portal pressure gradient measurement, injecting chemotherapy in PV and intrahepatic portosystemic shunt has expanded the horizons of endo-hepatology. Lastly, EUS has also forayed into cardiac interventions allowing pericardial fluid aspiration and tumour biopsy with experimental data on access to valvular apparatus. Herein, we provide a comprehensive review of the expanding paradigm of EUS-guided vascular interventions in GI bleeding, portal vein access and its related therapeutic interventions, cardiac access, and therapy. A synopsis of all the technical details involving each procedure and the available data has been tabulated, and the future trends in this area have been highlighted.

Quantitative measurements of esophageal varices using computed tomography for prediction of severe varices and the risk of bleeding: a preliminary study

BACKGROUND

We aimed to assess whether the quantitative parameters of esophageal varices (EV) based on computed tomography (CT) can noninvasively predict severe EV and the risk of esophageal variceal bleeding (EVB).

METHODS

A total of 136 endoscopically confirmed EV patients were included in this retrospective study and were divided into a non-conspicuous (mild-to-moderate EV, n = 30) and a conspicuous EV group (severe EV, n = 106), a bleeding (n = 89) and a non-bleeding group (n = 47). EV grade (EVG), EV diameter (EVD), cross-sectional surface area (CSA), EV volume (EVV), spleen volume (SV), splenic vein (SNV), portal vein (PV), diameter of left gastric vein (DLGV), and the opening type of LGV were measured independently using 3D-slicer. Univariate and multivariate logistic analysis were used to determine the independent factors and the receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic performance.

RESULTS

The difference of EVG, EVD, CSA, EVV, DLGV, SNV between the conspicuous and non-conspicuous EV group were statistically significant (p < 0.05), area under the curves (AUCs) of them for predicting severe EV were 0.72, 0.772, 0.704, 0.768, 0.707, 0.65, with corresponding sensitivities of 70.3%, 63.5%, 50%, 74.3%, 52.7%, 48.6%, specificities of 71.4%, 85.7%, 100%, 71.4%, 81%, 81%, respectively. EVG, CSA (odds ratio 3.258, 95% CI 1.597-6.647; 1.029, 95% CI 1.008-1.050) were found to be independent predictive factors. However, there was no significant difference of the included indices between the bleeding and non-bleeding group (p > 0.05).

CONCLUSIONS

CT can be used as a noninvasive method to predict the severity of EV, which may reduce the invasive screening of endoscopy.

The role of endoscopic ultrasound for portal hypertension in liver cirrhosis

Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced liver disease management. By establishing portal vein access, endoscopic ultrasound (EUS) has been utilized in various clinical applications. In comparison to standard upper gastrointestinal endoscopy, EUS-Doppler has been shown to be a better modality for detecting esophageal and gastric varices along with peri-esophageal collateral veins, para-esophageal collateral veins, and perforating veins, and may be used to objectively predict the recurrence of bleeding. EUS-guided portal vein catheterization has also been proposed to overcome the limitations of trans-jugular approaches. The combination of EUS-elastography and azygos vein evaluation can also enhance the diagnostic accuracy of each modality. Another well-known implementation of EUS-guided procedures is in the management of ascites; particularly in paracentesis and ascitic fluid analysis. In addition, the most common clinical application of EUS in the treatment of portal hypertension is through vascular therapy or creation of intrahepatic portosystemic shunts. Major drawbacks of EUS mainly revolve around technical difficulties, the high cost of the procedure, as well as the requirement of more studies in humans to evaluate EUS-guided advanced therapeutic modalities in portal hypertension.

The Role of Interventional Endoscopic Ultrasound in Liver Diseases: What Have We Learnt?

Chronic liver disease (CLD) is still a major problem, where the disease progression will lead to liver cirrhosis (LC) or hepatocellular carcinoma (HCC). Portal hypertension (PH) management and loco-regional therapy for HCC have become the cornerstones in advanced liver disease management. Recently, there are studies looking at the potential role of interventional endoscopic ultrasound (EUS) in liver diseases. EUS may be useful in vascular changes of the digestive wall evaluation, performing dynamic assessment of hemodynamic changes, predicting variceal bleeding and rebleeding risk, and assessing the pharmacological effects. In PH management, EUS-guided vascular therapy-which revolves around glue injection, endovascular coil placement/embolization, and combination of both-has shown promising results. As a diagnostic modality for liver cancer, the implementation of EUS in liver diseases is currently not only limited to liver biopsy (EUS-LB) but also in shear-wave elastography (SWE) and portal pressure gradient measurement, as well as portal vein sampling. The application of EUS-guided radiofrequency ablation (EUS-RFA) and tumor injection can also overcome the limitations shown by both modalities without EUS. Nevertheless, establishing EUS as a firm diagnostic and therapeutic modality is still challenging since the performance of interventional EUS requires high expertise and adequate facilities.

Multiparametric radiomics nomogram may be used for predicting the severity of esophageal varices in cirrhotic patients

Background

To explore whether a multiparametric radiomics nomogram on computed tomography (CT) images based on radiomics and relevant parameters of esophageal varices (EV) can be used for predicting the EV severity in patients with cirrhotic livers.

Methods

From January 2016 to August 2018, 136 consecutive patients with clinicopathologically confirmed liver cirrhosis were included for the development of a predictive model. The patients were then divided into two groups, including non-conspicuous EV group (mild-to-moderate EV, n=30) and conspicuous EV group (severe EV, n=106) by using the endoscopic validation as the reference standard. The radiomic scores (Rad scores) were constructed using the binary logistic regression model from the radiomics features of regions of interest (ROIs) in the left liver (LL) and right liver (RL), respectively. The multiparametric nomogram combined the best performance Rad-score and EV-relevant factors, and the calibration, discrimination, and clinical usefulness of developed nomogram were evaluated using calibration curves, decision curve analysis (DCA) and net reclassification index (NRI) analysis respectively.

Results

The LL Rad-score calculated from radiomics features was selected with a relatively higher area under the curve (AUC) (AUC; 0.88, training cohort; 0.87, the validation cohort) compared with RL Rad-score (AUC; 0.86, training cohort; 0.83, the validation cohort). In addition, cross-sectional surface area (CSA) was identified as the important predictor (P<0.05), the multiparametric nomogram containing LL Rad-score and CSA was shown to have a better predictive performance and good calibration in the training model (C-index, 0.953, 95% CI, 0.892 to 0.973) and the validation cohort (C-index, 0.938, 95% CI, 0.841 to 0.961), resulting in an improved NRI (categorical NRI of 25.9%, P=0.0128; continuous NRI of 120%, P<0.001) and integrated discriminatory improvement (IDI) (IDI =13.9%, P<0.001). DCA demonstrated that the multiparametric radiomics nomogram was clinically useful.

Conclusions

A multiparametric radiomics nomogram, which incorporates the liver radiomics signature and EV-relevant indices, is a useful tool for noninvasively predicting EV severity and may complement the standard endoscopy for evaluating EV severity in patients with cirrhosis.

Computed Tomographic Portography with Esophageal Variceal Measurements in the Evaluation of Esophageal Variceal Severity and Assessment of Esophageal Variceal Volume Efficacy

RATIONALE AND OBJECTIVES

The aim of our study is to evaluate the severity of esophageal varices (EV), based on the computed tomographic portography (CTP) measurement of EV in the distal esophagus and to assess the prediction value of EV volume.

PATIENTS AND METHODS

A total of 53 EV patients examined by CTP within 4 weeks of upper endoscopy were evaluated, the patients were divided into a nonconspicuous EV group (mild-to-moderate EV, n = 28) and a conspicuous EV group (severe EV, n = 25) according to endoscopy results. The diameter, cross-sectional surface area (CSA), and volume of EV were measured independently using 3D-slicer (Boston) by two experienced abdominal radiologists blinded to endoscopy findings. The averaged values measured by the two observers were used in the final dataset, these indicators' predictive performances were studied by using receiver operating characteristic curve analysis, and the area under the curve (A_z) and the cutoff values were calculated to distinguish mild-to-moderate from severe EV.

RESULTS

The A_z values of volume, diameter and CSA in differentiating severe EV were 0.817, 0.794, and 0.784 for observer-1, corresponding values for observer-2 were 0.796, 0.774, and 0.707, there was almost perfect interobserver agreement for all measurements. All indices were larger in the conspicuous group than the nonconspicuous group in both observers (p ≤ 0.01). In the final dataset, application of a 654.0-mm³-volume criterion yielded sensitivity, specificity of 96%, 50%, application of a 5.2-mm-diameter criterion yielded sensitivity, specificity of 80%, 75%, and application of a 68.6-mm²-CSA criterion yielded sensitivity, specificity of 52%, 93%.

CONCLUSION

The volume of EV could be used as a new effective indictor for evaluating EV, and use of volume, diameter, and CSA of EV based on CTP allows discrimination between mild-to-moderate and severe EV in cirrhotic patients.

Risk assessment of first upper gastrointestinal bleeding using computerized tomoscanning in esophageal varices patients with cirrhosis and portal hypertension

To evaluate the risk of first upper gastrointestinal bleeding by computerized tomoscanning (CT) for esophageal varices patients with cirrhotic portal hypertension.One hundred thirty two esophageal varices patients with cirrhotic portal hypertension who are also complicated with gastrointestinal bleeding were recruited as bleeding group, while another 132 patients without bleeding as non-bleeding group. The diameter of esophageal varices, number of vascular sections, and total area of blood vessels were measured by CT scanning. The sensitivity and specificity of these indicators were calculated, and Youden index was adjusted with the critical point.The diameter of esophageal varices was 7.83 ± 2.76 mm in bleeding group, and 6.57 ± 3.42 mm in non-bleeding group. The Youden index was 0.32 with the critical point 5.55 mm. The area under the receiver operating characteristics (AUROC) was 0.72. The number of venous vessels was 4.5 ± 2 in bleeding group, whereas being 4 ± 2 in non-bleeding group. The Youden index was 0.35 with a critical point 4, and the area under the curve (AUC) was 0.68. The blood vessel area was 1.73 ± 1.15 cm in bleeding group, and 1.12 ± 0.89 cm in non-bleeding group. The Youden index was 0.48 with the critical point being 1.03 cm, and corresponding AUC was 0.82.Among all 3 indicators of the total area, diameter, and number of sections of the esophageal varices, the total area of esophageal varices showed more accuracy as a potential and novel indicator for bleeding prediction.

The role of EUS in diagnosis and treatment of liver disorders

Background and aim  Transabdominal ultrasound (US), computed tomographic scanning (CT) and magnetic resonance imaging (MRI) are established diagnostic tools for liver diseases. Percutaneous transhepatic cholangiography is used to perform hepatic interventional procedures including biopsy, biliary drainage procedures, and radiofrequency ablation. Despite their widespread use, these techniques have limitations. Endoscopic ultrasound (EUS), a tool that has proven useful for evaluating the mediastinum, esophagus, stomach, pancreas, and biliary tract, has an expanding role in the field of hepatology complementing the traditional investigational modalities. This review aimed to assess the current scientific evidence regarding diagnostic and therapeutic applications of EUS for hepatic diseases.

Role of endoscopic ultrasound in liver disease: Where do we stand in 2017?

Endoscopic ultrasound (EUS) was first introduced into medical practice in 1980s as a diagnostic imaging modality for pancreatic pathology. EUS has the unique advantage of combining ultrasound and endoscopy to obtain detailed information of the gastrointestinal tract. Over the past decade, the use of EUS in liver diseases has been increasing. EUS, which was initially used as a diagnostic tool, is now having increasing therapeutic role as well. We provide a review of the application of EUS in the diagnostic and therapeutic aspects of liver disease. We also look at the evolving future research on the role of EUS in liver diseases.

Endoscopic ultrasonography predicts early esophageal variceal bleeding in liver cirrhosis: A case report

RATIONALE

Bleeding esophageal and gastric varices constitute a serious complication in liver cirrhosis. Previous studies have shown that endoscopic ultrasonography (EUS) can be used to predict early esophageal variceal bleeding in liver cirrhosis.

PATIENT CONCERNS

We report a case of a 46-year-old man with hepatitis B liver cirrhosis (CTP score, 5; Child-Pugh class, A) who was admitted to our hospital due to a decreased appetite lasting 1 week.

DIAGNOSIS

He was initially diagnosed with decompensated hepatitis B cirrhosis; an abdominal computed tomography (CT) scan indicated a diagnosis of liver cirrhosis and portal hypertension (PHT).

INTERVENTIONS

Common endoscopic examination showed no evidence of gastroesophageal varices; EUS revealed distinct varices of the esophageal and gastric veins. Six months after discharge, the patient was rehospitalized because of upper gastrointestinal bleeding. Endoscopic ligation was implemented as well as esophageal varices loop ligature (EVL).

OUTCOMES

Six months later, EUS showed obvious collateral and perforator veins.

LESSONS

We should strongly recommend that patients with liver cirrhosis undergo EUS in addition to a routine endoscopic examination. EUS can play an important role in evaluating the risk for bleeding in PHT and can be used to assess the efficacy of EVL.

Radiological score for hemorrhage in the patients with portal hypertension

GOAL

To analyze the risk factors from radiological indices for hemorrhage in the patients with portal hypertension and weight risk factors.

METHOD

We retrospectively analyzed all cases of portal hypertension with hepatitis B from June 2008 to June 2014 in Nanjing Drum Tower hospital. Patients with hepatocellular carcinoma, portal vein thrombosis, or portal hypertension with other causes, such as autoimmune hepatitis, pancreatitis, or hematological diseases were excluded.

RESULTS

Ninety-eight patients were recruited and divided into hemorrhage and non-hemorrhage groups. There were no statistical differences in clinical indexes such as age, prothrombin time, serum albumin, serum creatinine, serum sodium, hemameba, and blood platelet count. However, the differences were statistically significant in total bilirubin, hemoglobin, and liver function with the p values of 0.023, 0.000, and 0.039 respectively. For radiological indices, hemorrhage was correlated with diameter of inferior mesenteric vein (P=0.0528), posterior gastric vein (P=0.0283), and esophageal varices scores (P=0.0221). Logistic procedure was used to construct the model with stepwise selection and finally inferior mesenteric vein, posterior gastric vein, esophageal varices, and short gastric vein were enrolled into the model. These veins were scored according to the diameters and the rates of hemorrhage were increased with the score. We then validated the model with 26 patents from July 2014 to December 2014. The AUC value was 0.8849 in ROC curves for this radiological model.

CONCLUSIONS

A risk model was constructed including inferior mesenteric vein, esophageal varices, posterior gastric vein, and short gastric vein. This radiological scoring model may be a valuable indicator for hemorrhage of portal hypertension.

Utility of endoscopic ultrasound in the diagnosis and management of esophagogastric varices

Endoscopic ultrasound (EUS) has significantly improved our understanding of the complex vascular structural changes in patients with portal hypertension. At present, EUS is a useful diagnostic tool for the evaluation of esophagogastric varices (EGVs) and guidance of endoscopic therapy. Several studies have employed this new technique for the diagnosis and management of esophageal and gastric varices, respectively. In the present review, we have summarized the current status of EUS for the diagnosis and management of EGVs and clarified the clinical feasibility of this procedure. New indications for EUS can be developed in the future after adequate validation.

Endoscopic management of esophagogastric varices in Japan

Esophagogastric varices are the most common complication in patients with portal hypertension, and endoscopy plays an important role in their diagnosis and in the prevention of acute bleeding from these structures. Recently, new modalities such as endoscopic ultrasonography (EUS) and narrow-band imaging have been introduced for the diagnosis of esophagogastric varices. In Japan, endoscopic therapy has become the first choice for the treatment of acutely bleeding esophageal or gastric varices. The two principal methods used to treat esophageal varices are endoscopic injection sclerotherapy (EIS) and endoscopic variceal ligation (EVL). Recently, combinations of EIS plus EVL and EVL plus argon plasma coagulation were reported to be more effective than EVL or EIS alone. Additionally, endoscopic cyanoacrylate injection is superior to EIS and EVL for the treatment of acutely bleeding gastric varices.

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.

Usefulness of endoscopic ultrasound in esophagogastric varices

Endoscopic ultrasound (EUS) is a useful diagnostic tool for evaluation of esophagogastric varices and guidance of endoscopic therapy. EUS can visualize not only collateral veins around the esophagus but also perforating veins that connect esophageal varices with collateral veins. They are associated with high risk of bleeding and early recurrence after initial variceal eradication. Isolated gastric varices can be easily diagnosed using EUS that mimic thickened gastric folds or subepithelial tumors. EUS-guided endoscopic therapy is a challenging field of variceal bleeding. It has a potential role for assistance of interventions and evaluation of treatment outcome.

Current staging and diagnosis of gastroesophageal varices

Portal hypertension is defined as an increase in hepatic sinusoidal pressure to 6 mm Hg or higher. Cirrhosis is the most common cause of portal hypertension in the western world and results from increased resistance to blood flow at the hepatic sinusoidal level.

Endoscopic ultrasonography and portal hypertension: where are we in 2009?

Endoscopic ultrasonography is currently a sensitive diagnostic and therapeutic tool with established indications, but its role in the management of portal hypertension is not well defined. This article briefly reviews indications, technologic improvements, diagnostic and interventional applications of endoscopic ultrasonography in portal hypertension.

Systematic review: endoscopic and imaging-based techniques in the assessment of portal haemodynamics and the risk of variceal bleeding

BACKGROUND

Invasive measurement of the hepatic venous pressure gradient (HVPG) is regarded as the gold standard for risk stratification and the evaluation of pharmaceutical agents in patients with portal hypertension.

AIM

To review the techniques for endoscopic and imaging-based assessment of portal haemodynamics, with particular emphasis on trials where the results were compared with HVPG or direct portal pressure measurement.

METHODS

Systematic search of the MEDLINE electronic database with keywords: portal hypertension, variceal bleeding, variceal pressure, endoscopic ultrasound, Doppler ultrasonography, magnetic resonance angiography, CT angiography, hepatic venous pressure gradient.

RESULTS

Computed tomography angiography and endoscopic ultrasound (EUS) have been both employed for the diagnosis of complications of portal hypertension and for the evaluation of the efficacy of endoscopic therapy. Colour Doppler ultrasonography and magnetic resonance angiography has given discrepant results. Endoscopic variceal pressure measurements either alone or combined with simultaneous EUS, correlate well with HVPG and risk of variceal bleeding and have a low interobserver variability.

CONCLUSIONS

Endoscopic and imaging-based measurements of portal haemodynamics provide an alternate means for the assessment of complications of portal hypertension. Further studies are required to validate their use in risk stratification and the evaluation of drug therapies in patients with portal hypertension.

Minimally invasive measurement of esophageal variceal pressure and wall tension (with video)

BACKGROUND

There is no simple method to measure intravariceal pressure in patients with esophageal varices.

OBJECTIVE

Our purpose was to develop a new noninvasive technique to measure resting intravariceal pressure and wall tension.

DESIGN

A model was developed. A long balloon (varix) was fitted inside an airtight cylinder (esophagus). Fluid ran through the model varices to maintain 5 different constant pressures. An endoscope was placed in the model esophagus, and pressure was increased by air insufflation. The endoscopy and pressure readings from the esophagus and varix were recorded continuously until variceal collapse.

SETTING

Patient studies were done in an endoscopy suite with the patient under fentanyl and midazolam sedation.

PATIENTS

Esophageal pressure was measured during air insufflation in patients with varices until the varices collapsed. EUS was used to measure radius and wall thickness to calculate wall tension.

RESULTS

In the varix model, the mean (SD) intraluminal esophageal pressures at variceal flattening for the model varices at 5, 10, 15, 20, and 25 mm Hg were 5.69 (0.34), 11 (0.32), 15.72 (0.51), 21.55 (0.63), and 25.8 (0.14) mm Hg. The correlation between actual and measured variceal pressure in the model at variceal flattening was r = 0.98. In the patients, a total of 10 varices in 3 patients were evaluated. The mean (SD) for the varices in each subject was 12.16 (2.4), 23.2 (1.3), and 6.5 (2.2) mm Hg for subjects 1, 2, and 3, respectively.

CONCLUSION

Standard endoscopy with air insufflation and manometry can be used as an accurate, simple, and reproducible method to measure intravariceal pressure.

Mechanics and hemodynamics of esophageal varices during peristaltic contraction

Our hypothesis states that variceal pressure and wall tension increase dramatically during esophageal peristaltic contractions. This increase in pressure and wall tension is a natural consequence of the anatomy and physiology of the esophagus and of the esophageal venous plexus. The purpose of this study was to evaluate variceal hemodynamics during peristaltic contraction. A simultaneous ultrasound probe and manometry catheter was placed in the distal esophagus in nine patients with esophageal varices. Simultaneous esophageal luminal pressure and ultrasound images of varices were recorded during peristaltic contraction. Maximum variceal cross-sectional area and esophageal luminal pressures at which the varix flattened, closed, and opened were measured. The esophageal lumen pressure equals the intravariceal pressure at variceal flattening due to force balance laws. The mean flattening pressures (40.11 +/- 16.77 mmHg) were significantly higher than the mean opening pressures (11.56 +/- 25.56 mmHg) (P < or = 0.0001). Flattening pressures >80 mmHg were generated during peristaltic contractions in 15.5% of the swallows. Variceal cross-sectional area increased a mean of 41% above baseline (range 7-89%, P < 0.0001) during swallowing. The peak closing pressures in patients that experience future variceal bleeding were significantly higher than the peak closing pressures in patients that did not experience variceal bleeding (P < 0.04). Patients with a mean peak closing pressure >61 mmHg were more likely to bleed. In this study, accuracy of predicting future variceal bleeding, based on these criteria, was 100%. Variceal models were developed, and it was demonstrated that during peristaltic contraction there was a significant increase in intravariceal pressure over baseline intravariceal pressure and that the peak intravariceal pressures were directly proportional to the resistance at the gastroesophageal junction. In conclusion, esophageal peristalsis in combination with high resistance to blood flow through the gastroesophageal junction leads to distension of the esophageal varices and an increase in intravariceal pressure and wall tension.

Assessment of donor liver steatosis: pathologist or automated software?

Steatosis in donor liver biopsy specimens has been shown to correlate with graft dysfunction after orthotopic liver transplantation. This 2-part (laboratory pilot, clinical retrospective) study compared the traditional interpretation of steatosis by a pathologist with an automated measurement determined by an image analysis system. In our pilot study, Sprague-Dawley rats were studied prospectively by feeding them a choline-deficient diet for up to 7 days. In our clinical group, data from 49 consecutive recipients of cadaveric liver transplantation were reviewed retrospectively. In both studies, the percentages of microvesicular fat, macrovesicular fat, and total fat content within liver biopsy specimens were determined by an automated image analysis software program and a pathologist using the same set of slides. The association between fat content of the donor liver and patient survival and graft survival, along with levels of aspartate aminotransferase, alanine aminotransferase, prothrombin time, and total bilirubin after transplantation, were also examined in the clinical study. A direct correlation was observed between levels of macrovesicular fat determined by a pathologist and the automated software using livers from rats fed a choline-deficient diet and livers from deceased donors. A significant association was observed between macrovesicular fat content in the donor liver biopsy and graft survival by both techniques. We conclude that an image analysis system can be used to automate the determination of fat content in liver biopsy specimens, and that its findings correlate with both the visual interpretation by a pathologist and graft survival. Further study is needed to determine the role of an automated technique in the evaluation of donor livers for transplantation.

Portal hypertension

PURPOSE OF REVIEW

This review discusses the advances in the pathophysiology, diagnosis, and management of the complications of portal hypertension that have occurred in the past year.

RECENT FINDINGS

The specific topics reviewed are the pathophysiology of portal hypertension (including recent findings regarding intrahepatic vascular resistance and splanchnic vasodilatation) and experimental methods used to act on the mechanisms that lead to portal hypertension, as well as recent advances in the diagnosis and management of the complications of portal hypertension.

SUMMARY

The specific complications discussed in this review are varices and variceal bleeding (primary prophylaxis, treatment of the acute episode, and secondary prophylaxis), portal hypertensive gastropathy, ascites, hepatorenal syndrome, spontaneous bacterial peritonitis, the cardiopulmonary complications of portal hypertension (hepatopulmonary syndrome, portopulmonary hypertension, cardiac dysfunction), and hepatic encephalopathy.

The role of endoscopy in the treatment of esophageal varices, 2002-2003

Great strides have been made in the endoscopic and radiologic therapy of esophageal varices in the past few years. With the advent of variceal band ligation and transjugular intrahepatic portosystemic shunt, almost every acute variceal bleed can be controlled. In addition, over the past decade great strides have been made in the noninvasive imaging and pressure measurement of esophageal varices. Yet, the mortality rate from variceal bleeding has not changed significantly and the pharmacologic therapy of esophageal varices and the prophylaxis of the initial variceal bleed has lagged behind these other interventional advances. These authors believe that progress in these areas has been slow because the pathophysiology and hemodynamics of esophageal varices are not well understood. It is through progress in the areas of endoluminal ultrasound imaging of esophageal varices and noninvasive pressure measurement that progress has finally been made in the area of the pathophysiology of variceal bleeding. In this update, two novel ideas regarding the pathophysiology of variceal bleeding are described. The first regards increased variceal pressure during peristaltic contraction. The second describes increased variceal pressure with increasing intraabdominal pressure. These new observations suggest a new pathophysiology in the cause of variceal bleeding and imply new methods to prevent and treat variceal bleeding. This update and review of esophageal varices is given in five sections: new developments in the pathophysiology of esophageal variceal bleeding, screening for esophageal varices, prediction of variceal bleeding, treatment of esophageal varices and new modalities to evaluate esophageal varices.