A new ultrasound-guided esophageal variceal pressure-measuring device

Endoscopic ultrasound in portal hypertension: navigating venous hemodynamics and treatment efficacy

Portal hypertension-related complications increase mortality in patients, irrespective of its etiology. Classically, endoscopic ultrasound (EUS) was used to assess the portal venous system and collaterals, considering size and hemodynamic parameters, which correlate with portal hypertension (PH) and related complications. Furthermore, therapeutic EUS guides treatment interventions, such as embolization of the gastric varices through coil placement and tissue adhesive injection, yielding encouraging clinical results. Recently, the direct measurement of portal pressure, emerging as an alternative to hepatic venous pressure gradient, has shown promise, and further research in this area is anticipated. In this review, we aimed to provide a detailed description of various possibilities for diagnosing vascular anatomy and hemodynamics in PH and actual knowledge on the EUS usefulness for PH vessel-related complications. Also, future promises for this field of endo-hepatology are discussed.

A novel fiber-optic pressure sensor device for measuring variceal pressure

It has been reported that variceal pressure can predict the occurrence of variceal bleeding. However, the majority of methods presently used to measure variceal pressure are either invasive or inconvenient. In the present study, a fiber-optic pressure sensor was constructed to detect variceal pressure. The prospective study focused on the in vitro accuracy of a fiber-optic pressure sensor and investigated the clinical reliability and feasibility of this method. The fiber-optic pressure sensor covered a pressure-sensitive probe containing a fiber-optic pressure sensor and a workstation to record the pressure tracing. It was hypothesized that the endoscopic fiber-optic pressure sensor can effectively predict the risk of variceal bleeding. To test this hypothesis, 80 patients who suffered from cirrhosis and who had a history of variceal bleeding were included in the present study. The fiber-optic pressure sensor was guided through the biopsy channel using an endoscope in the patient cohort. Transjugular intrahepatic stent-shunt (TIPS) was subsequently performed within 24 h after measuring variceal pressure. A comparison of the results of the 80 patients was made between variceal pressure measured by the endoscopic fiber-optic pressure sensor and the portal pressure gradient (PPG) measured by a TIPS. The variceal pressure measurements with the fiber-optic pressure sensor were technically satisfactory in 78 patients. The results indicated that there was a linear correlation between the variceal pressure measured by the endoscopic fiber-optic pressure sensor and the PPG (r=0.940, P<0.001). These observations suggest that the fiber-optic pressure sensor is an accurate and feasible measurement technique. Therefore, the results of the present study indicate that the endoscopic fiber-optic pressure sensor is effective in predicting the risk of variceal bleeding.

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.

Validation of an Endoscopic Fibre-Optic Pressure Sensor for Noninvasive Measurement of Variceal Pressure

In this study, the authors have developed endoscopic fibre-optic pressure sensor to detect variceal pressure and presented the validation of in vivo and in vitro studies, because the HVPG requires catheterization of hepatic veins, which is invasive and inconvenient. Compared with HVPG, it is better to measure directly the variceal pressure without puncturing the varices in a noninvasive way.

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.

Effects of propranolol or propranolol plus isosorbide-5-mononitrate on variceal pressure in schistosomiasis

AIM: To compare the effects of propranolol (PR) to that of PR plus isosorbide-5-mononitrate (ISMN) on variceal pressure in patients with schistosomiasis.

METHODS: Forty-eight patients with schistosomiasis who had no previous variceal bleeding were treated with PR alone or PR plus ISMN. Seven patients refused variceal pressure manometry (3 receiving PR and 4 receiving PR plus ISMN). One patient withdrew from the trial due to headache after taking ISMN. At the time of termination, twenty patients were randomly assigned to treatment with PR plus ISMN or PR alone. The dose of PR was adjusted until the resting heart rate had been reduced by 25% or was less than 55 bpm. In the PR plus ISMN group, after PR was titrated to the same target, the dose of ISMN was increased up to 20 mg orally twice a day. Variceal pressure was measured using a noninvasive endoscopic balloon technique at the end of the 6-mo treatment period.

RESULTS: In 40 patients (20 in the PR group and 20 in the PR plus ISMN group), variceal pressure was measured before treatment and at the end of the 6-mo treatment period. PR or PR plus ISMN treatment caused a significant reduction in variceal pressure (PR group: from 24.15 ± 6.05 mmHg to 22.68 ± 5.70 mmHg, P = 0.001; PR plus ISMN group: from 25.69 ± 5.26 mmHg to 20.48 ± 5.43 mmHg; P < 0.001). The percentage decrease in variceal pressure was significant after PR plus ISMN compared with that after PR alone (15.93% ± 8.37% vs 6.05% ± 3.67%, P = 0.01). One patient in the PR plus ISMN group and two patients in the PR group had variceal bleeding during follow-up. There were no significant differences between the two groups regarding the incidence of variceal bleeding. In the PR plus ISMN group, three patients had headache and hypotension. The headache was mild and transient and promptly disappeared after continuation of the relevant drug in two patients. Only one patient withdrew from the trial due to severe and lasting headache after taking ISMN. No side effects occurred in the PR group.

CONCLUSION: PR plus ISMN therapy may be an alternative treatment for patients with schistosomiasis who have a high risk of bleeding.

Measurement of variceal pressure with a computerized endoscopic manometry: validation and effect of propranolol therapy in cirrhotic patients

Background and Purpose

Recently, we invented a computerized endoscopic balloon manometry (CEBM) to measure variceal pressure (VP) in cirrhotic patient. The purpose of this study was to evaluate the reliability and feasibility of this method, and whether this technique provided further information to pharmacological therapy.

Patients and Methods

VP measurements were performed in 83 cirrhotic patients and compared with HVPG as well as endoscopic bleeding risk parameters. Furthermore, VP was assessed before and during propranolol therapy in 30 patients without previous bleeding.

Results

VP measurements were successful in 96% (83/86) of all patients. Of the 83 patients, the VP correlated closely with the HVPG (P<0.001). The presence of red colour signs and the size of varices were strongly associated with VP. Patients with previous bleeding had higher VP than those who had not yet experienced bleeding. In univariate analysis, the level of VP, the size of varices, and red color signs predicted a higher risk of bleeding. The multiple logistic regression model revealed that VP was the major risk factor for bleeding. In 30 patients receiving propranolol, VP significantly decreased from 21.1±3.5 mmHg before therapy to 18.1±3.3 mmHg after 3 months and to 16.3±4.0 mmHg after 6 months. Comparing the mean decrease in VP with that in hepatic venous pressure gradient (HVPG), the decrease in VP was more obvious than HVPG response to propranolol.

Conclusions

This study showed that CEBM is safe and practical to assess VP in cirrhotic patient. It has the potential to be used as a clinical method to assess the risk of variceal bleeding and the effects of pharmacological therapy.

Trial registration

Effect of vasoactive drugs on esophageal variceal hemodynamics in patients with portal hypertension. Chinese Clinical Trial Registry –TRC-08000252.

Endo-hepatology: a new paradigm

Recent advances in hepatology have included a new and effective treatment of viral hepatitis, with an increased need for the assessment of liver function and histology. At the same time, there have been a growing number of endoscopic procedures that are pertinent to patients with liver disease. It would be ideal if the assessment and treatment of liver disease and portal hypertension could be performed and assimilated by the liver/gastrointestinal specialist. The authors like to consider this area of integration or overlap of endoscopic procedures within the practice of hepatology as endo-hepatology.

[Recent advances in diagnosis of portal hypertension]

Complications of portal hypertension are major concerns in liver cirrhosis and significant morbidity and mortality mainly because of variceal bleeding, ascites, bacterial infections, hepatic encephalopathy, and hepatorenal syndrome. Various modalities in the diagnosis of portal hypertension are reviewed. The measurement of hepatic venous pressure gradient (HVPG) is a simple, invasive, reproducible method and regarded as the gold standard for the diagnosis and staging of portal hypertension. Other tests such as transient elastography, per-endoscopic variceal pressure measurement, endoscopic ultrasonography, and Doppler ultrasonography may be complementary and promising.

Endoscopic ultrasonography for the evaluation of portal hypertension

Since the 1980s, endoscopic ultrasonography (EUS) has been useful in the evaluation of portal hypertension, either for the diagnostic aspects or for the evaluation of therapy and risk of bleeding. More recently, it has been described as a method for guiding interventions such as variceal injection, portal vein catheterization, or even for creating an intrahepatic portosystemic shunt in the animal laboratory. The new generation of radial electronic echoendoscopes is equipped with color Doppler capability, allowing for measurement of any hemodynamic parameter of the portal circulation. This article summarizes the current knowledge on the role of EUS for the evaluation of portal hypertension.

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.