Endoscopic Ultrasound-Guided Porto-systemic Pressure Gradient Measurement Correlates with Histological Hepatic Fibrosis

Endoscopic procedures in hepatology: Current trends and new developments

Gastrointestinal endoscopy has long been a reliable backbone in the diagnosis and management of hepatobilary disorders and their complications. However, with evolving non-invasive testing, personalised medicine has reframed the utility and necessity of endoscopic screening. Conversely, the growing interest and use of endoscopic ultrasound (EUS) and advanced endoscopy within gastrointestinal units has also opened novel diagnostic and therapeutic avenues for patients with various hepatobiliary diseases. The integration of "advanced endoscopy" within the practice of hepatology is nowadays referred to as "endo-hepatology". In essence, endo-hepatology consists of two pillars: one focusing primarily on disorders of the liver parenchyma, vascular disorders, and portal hypertension, which is mainly captured via EUS, while the other targets the hepatobiliary tract via endoscopic retrograde cholangiopancreatography and advanced imaging. Applications under the umbrella of endo-hepatology include, amongst others, EUS-guided liver biopsy, EUS-guided portal pressure gradient measurement, coil and glue embolisation of gastric varices as well as cholangioscopy. As such endo-hepatology could become an attractive concept wherein advanced endoscopy might reinforce the medical management of patients with hepatobiliary disorders and their complications after initial basic work-up. In this review, we discuss current trends and future developments within endo-hepatology and the remaining hurdles to overcome.

Role of endoscopy in hepatology

The growing and evolving field of EUS and advanced hepatobiliary endoscopy has amplified traditional upper gastrointestinal endoscopy and unveiled novel options for remaining unsolved hepatobiliary issues, both diagnostically and therapeutically. This conceptually appealing and fascinating integration of endoscopy within the practice of hepatology is referred to as 'endo-hepatology'. Endo-hepatology focuses on the one hand on disorders of the liver parenchyma and liver vasculature and of the hepatobiliary tract on the other hand. Applications hanging under the umbrella of endohepatology involve amongst others EUS-guided liver biopsy, EUS-guided portal pressure measurement, EUS-guided portal venous blood sampling, EUS-guided coil & glue embolization of gastric varices and spontaneous portosystemic shunts as well as ERCP in the challenging context of (decompensated cirrhosis) and intraductal cholangioscopy for primary sclerosing cholangitis. Although endoscopic proficiency however does not necessarily equal in an actual straightforward end-solution for currently persisting (complex) hepatobiliary situations. Therefore, endohepatology continues to generate high-quality data to validate and standardize procedures against currently considered (best available) "golden standards" while continuing to search and trying to provide novel minimally invasive solutions for persisting hepatological stalemate situations. In the current review, we aim to critically appraise the status and potential future directions of endo-hepatology.

Activation of cGAS-STING signaling pathway promotes liver fibrosis and hepatic sinusoidal microthrombosis

Inflammation plays an essential role in the development liver fibrosis.The Cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) is a central cytoplasmic DNA sensor which can recognize cytoplasmic DNA, known to trigger stimulator of interferon genes (STING) and downstream proinflammatory factors. Here, we investigated the role of cGAS-STING signaling pathway in the pathogenesis of liver fibrosis.Differentially expressed genes (DEGs) in human liver tissue were identified using RNA-Seq analysis. As models of liver fibrosis, chronic Carbon tetrachloride (CCl4) exposure were applied in cGAS-knockout mice. LX-2 cells were co-cultured with human liver sinusoidal endothelial cells (LSECs) to explore the underlying mechanisms of hepatic sinusoidal microthrombosis in an inflammatory microenvironment. The endoscopic ultrasound-guided portal vein pressure gradient (EUS-PPG) method was used to analyze the associations between hepatic sinusoidal microthrombosis and PPG in patients with liver fibrosis and portal hypertension (PTH). The RNA-seq analysis results showed that DEGs were enriched in inflammation and endothelial cell activation. The upregulation of the cGAS-STING signaling exacerbated liver fibrosis and intrahepatic inflammation. It also exacerbated LSECs impairment and increased the contribution of hepatic sinusoidal microthrombosis to liver fibrosis in vivo and in vitro. Prothrombotic mediators and proinflammatory factors were associated with PPG in patients with liver fibrosis and portal hypertension. Therefore, activating cGAS-STING signaling pathway promotes liver fibrosis and hepatic sinusoidal microthrombosis, which may lead to increased portal vein pressure.

Advances in Endohepatology

Over the past decade, the number of endoscopic procedures relevant to patients with liver disease not only increased but also altered and expanded in terms of indications and applications. "Endohepatology" refers to the integration of advanced endoscopy within the practice of hepatology with endoscopic ultrasound as one of the main pillars. Current applications under the umbrella of endohepatology focus on advanced diagnostics and oncological, vascular, and metabolic interventions. These involve, among others, endoscopic ultrasound (EUS)-guided liver biopsy, EUS-guided portal pressure gradient measurement, and EUS-guided coil and glue embolization of gastric varices. In addition to its conceptually attractive technical and innovative characteristics, endohepatology is also an appealing practical option for daily practice because it can be offered as a "one-stop clinic" intervention where comprehensive endoscopic diagnostic and/or therapeutic testing is performed in a single outpatient visit. In this review, we will discuss current trends and future developments within endohepatology and the remaining hurdles to overcome.

AGA Clinical Practice Update on Interventional EUS for Vascular Investigation and Therapy: Commentary

DESCRIPTION

The purpose of this AGA Institute Clinical Practice Update is to review the available evidence supporting and examine opportunities for future research in endoscopic ultrasound-guided vascular investigation and therapies.

METHODS

This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors who are advanced endoscopists with expertise in endoscopic ultrasound-guided vascular investigation and therapy.

Endoscopic Advances in Hepatology

Endoscopy is and remains an indispensable tool in diagnosing and managing liver disease and its complications. Due to the progress in advanced endoscopy, endoscopy has become an alternative route for many surgical, percutaneous, and angiographic interventions, not only as a backup tool when conventional interventions fail but increasingly as a first-line choice. The term endo-hepatology refers to the integration of advanced endoscopy in the practice of hepatology. Endoscopy is key in the diagnosis and management of esophageal and gastric varices, portal hypertensive gastropathy, and gastric antral vascular ectasia. Endoscopic ultrasound (EUS) can be used for the evaluation of the liver parenchyma, liver lesions, and surrounding tissues and vessels, including targeted biopsy and complemented with new software functions. Moreover, EUS can guide portal pressure gradient measurement, and assess and help manage complications of portal hypertension. It is crucial that each present-day hepatologist is aware of the (rapidly increasing) full spectrum of diagnostic and therapeutic tools that exist within this field. In this comprehensive review, we would like to discuss the current endo-hepatology spectrum, as well as future directions for endoscopy in hepatology.

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.

The use of endoscopic ultrasound in the diagnosis and management of portal hypertension

The role of endoscopic ultrasound in the diagnosis and management of chronic liver disease is rapidly increasing. It forms one of the major backbones of endo-hepatology and brings us a step closer to personalized medicine. This review will focus on the particular use of EUS in the diagnosis and management of cirrhotic portal hypertension and potential complications hereof, such as ascites and gastrooesophageal varices. More specifically, EUS-guided Porto-systemic Pressure Gradient (EUS-PPG) measurement, EUS-guided coil and glue embolization of gastric varices, EUS-guided paracentesis and EUS-guided intrahepatic portosystemic shunt creation (IPSS) will be discussed in-depth with regard to clinical status, available data and technical considerations.