A new alternative for a transjugular intrahepatic portosystemic shunt: EUS-guided creation of an intrahepatic portosystemic shunt (with video)

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.

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.

Interventional Endoscopic Ultrasound: Current Status and Future Frontiers

Interventional endoscopic ultrasound has fueled remarkable advancements in the field of therapeutic procedures, revolutionizing minimally invasive interventions for a diverse range of conditions. This review highlights the latest breakthroughs and advancements in therapeutic endoscopic ultrasound, showcasing its potential to transform patient care.

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 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 Role of Endoscopic Ultrasound in Hepatology

Endoscopic ultrasound (EUS) has been an indispensable and widely used diagnostic tool in several medical fields, including gastroenterology, cardiology, and urology, due to its diverse therapeutic and diagnostic applications. Many studies show that it is effective and safe in patients with liver conditions where conventional endoscopy or cross-sectional imaging are inefficient or when surgical interventions pose high risks. In this article, we present a review of the current literature for the different diagnostic and therapeutic applications of EUS in liver diseases and their complications and discuss the potential future application of artificial intelligence analysis of EUS.

EUS-Guided Vascular Interventions

Endoscopic ultrasound (EUS) has numerous advanced applications as a diagnostic and therapeutic modality in contemporary medicine. Through intraluminal placement, EUS offers a real-time Doppler-guided endoscopic visualization and access to intra-abdominal vasculature, which were previously inaccessible using historical methods. We aim to provide a comprehensive review of key studies on both current and future EUS-guided vascular applications. This review details EUS-based vascular diagnostic techniques of portal pressure measurements in the prognostication of liver disease and portal venous sampling for obtaining circulating tumor cells in the diagnosis of cancer. From an interventional perspective, we describe effective EUS-guided treatments via coiling and cyanoacrylate injections of gastric varices and visceral artery pseudoaneurysms. Specific attention is given to clinical studies on efficacy and procedural techniques described by investigators for each EUS-based application. We explore novel and future emerging EUS-based interventions, such as liver tumor ablation and intrahepatic portosystemic shunt placement.

Endoscopic ultrasound-guided diagnosis and treatment of gastric varices

Gastric varices (GV) represent a common and severe complication in patients with portal hypertension, commonly seen in patients with cirrhosis and severe pancreatic disease. Endoscopic ultrasonography is a safe and efficacious approach that can perform real-time ultrasonic scanning and intervention for the gastrointestinal submucosa, portal vein and its tributaries, and collateral circulations during direct endoscopic observation. Recently, various studies have been published about endoscopic ultrasound (EUS)-guided management of GV, mainly including diagnosis, treatment, and prognostic analysis. This article reviews published articles and guidelines to present the development process and current management of EUS-guided GV procedures.

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.

Variceal Bleeding: Beyond Banding

Despite advances in the management of complications of portal hypertension, variceal bleeding continues to be associated with significant morbidity and mortality. While endoscopic variceal band ligation remains first line therapy for treating bleeding and high-risk non-bleeding esophageal varices, alternate therapies have been explored, particularly in cases of refractory bleeding. The therapies being explored include stent placement, hemostatic powder use, over-the-scope clips and others. For gastric variceal bleeding, endoscopic ultrasound-guided therapies have recently emerged as promising interventions for hemostasis. The aim of this article is to highlight these alternative therapies and their potential role in the management of gastric and esophageal variceal bleeding.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

Role of endoscopic ultrasound in the field of hepatology: Recent advances and future trends

The role of endoscopic ultrasound (EUS) as a diagnostic and therapeutic modality for the management of various gastrointestinal diseases has been expanding. The imaging or intervention for various liver diseases has primarily been the domain of radiologists. With the advances in EUS, the domain of endosonologists is rapidly expanding in the field of hepatology. The ability to combine endoscopy and sonography in one hybrid device is a unique property of EUS, together with the ability to bring its probe/transducer near the liver, the area of interest. Its excellent spatial resolution and ability to provide real-time images coupled with several enhancement techniques, such as contrast-enhanced (CE) EUS, have facilitated the growth of EUS. The concept of “Endo-hepatology” encompasses the wide range of diagnostic and therapeutic procedures that are now gradually becoming feasible for managing various liver diseases. Diagnostic advancements can enable a wide array of techniques from elastography and liver biopsy for liver parenchymal diseases, to CE-EUS for focal liver lesions to portal pressure measurements for managing various liver conditions. Similarly, therapeutic advancements range from EUS-guided eradication of varices, drainage of bilomas and abscesses to various EUS-guided modalities of liver tumor management. We provide a comprehensive review of all the different diagnostic and therapeutic EUS modalities available for the management of various liver diseases. 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.

Endoscopic ultrasound guided hepatic interventions

Intervention for liver disease has predominantly been performed through the percutaneous approach. However, as endoscopic ultrasound (EUS) applications have expanded, there have emerged various EUS-guided interventions for liver disease, a space we call "Endo-Hepatology". EUS-guided liver biopsy can be considered the "forerunner" of Endo-Hepatology and has become a clinical option for patients requiring histologic diagnosis and staging of their liver disease. EUS also enables direct access to the portal vein. Subsequently, many procedures are being explored, such as angiography, measurement of the portosystemic pressure gradient, portal vein sampling to detect cancer cell or DNA, and EUS-guided transhepatic intrahepatic portosystemic shunt creation. Since the transducer is close to the liver, especially the left and caudate lobes, EUS can be used as a rescue when the percutaneous approach is not favorable and EUS-guided treatments of liver tumor, cyst and abscess have been reported. This review summarizes the available studies of EUS-guided intervention in the liver.

Endoscopic Diagnosis and Management of Gastrointestinal Trauma

Trauma affects all sociodemographic profiles and is a major cause of morbidity and mortality particularly in patients less than forty years of age. A variety of endoscopic tools and techniques initially used for iatrogenic etiologies (post-operative bile or pancreatic duct leaks, intra-procedural perforation) have been adopted for use in the gastrointestinal trauma victim. The purpose of this review is to highlight a variety of gastrointestinal traumatic complications where endoscopy can serve a complement and/or definitive management strategy.

Endoscopic Ultrasound-Guided Vascular Procedures: A Review

Since the 1980s, endoscopic ultrasound has advanced from being purely diagnostic to an interventional modality. The gastrointestinal tract offers an exceptional window for assessing the vascular structures in the mediastinum and in the abdomen. This has led to a rapidly growing interest in endoscopic ultrasound-controlled vascular interventions as a minimally invasive alternative to surgical and radiological procedures.

Safety, Diagnostic Accuracy, and Effects of Endoscopic Ultrasound Fine-Needle Aspiration on Detection of Extravascular Migratory Metastases

BACKGROUND & AIMS

Tumor cells can migrate via diminutive perivascular cuffing to distant sites along blood vessels to form extravascular migratory metastases (EVMM). These metastases usually are identified during surgery or autopsies. We aimed to evaluate the feasibility and safety of endoscopic ultrasound fine-needle aspiration (EUS-FNA) of perivascular soft-tissue cuffs to detect EVMM. We compared findings from EUS with those from noninvasive cross-sectional imaging (reference standard) of patients who underwent EUS-FNA to assess suspected EVMM and studied the effects on pancreatic tumor staging and determination of resectability.

METHODS

We performed a retrospective analysis of 253 patients (mean age, 62 ± 12 y) who underwent EUS-FNA of 267 vessels for evaluation of suspected EVMM, from April 2001 through May 2018. EUS findings were compared with those from computed tomography (CT) and magnetic resonance imaging (MRI) as the reference standard. Lesions were considered to be malignant based on cytology analysis of FNA samples, histology analyses of surgical or biopsy specimens, or vascular abnormalities detected by CT or MRI that clearly indicate EVMM.

RESULTS

Thirty patients were found to have benign lesions. The remaining 223 patients who had malignancies (166 with pancreatic ductal adenocarcinomas [PDACs]), underwent further analyses. A median of 4 FNAs (range, 1-20 FNAs) were obtained from 4-mm perivascular soft-tissue cuffs (range, 2-20 mm). FNA and cytology analysis showed malignant cells in 163 vessels (69.4%) from 157 patients (70.4%). CT or MRI did not detect EVMM in 44 patients (28%) with malignancies, including 24 patients (24%) with newly diagnosed PDAC. Detection of EVMM by EUS-FNA resulted in upstaging of 15 patients and conversion of 14 patients with PDAC from resectable (based on CT or MRI) to unresectable. No adverse events were reported during a follow-up period of 3.9 months (range, 0-117 mo).

CONCLUSIONS

EUS-FNA and cytologic analysis of perivascular soft-tissue cuffs can detect EVMM that were not found in 28% of patients by CT or MRI. Detection of EVMM affects tumor staging and determination of tumor resectability.

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.

Insights into the role of endoscopic ultrasound-guided vascular therapy

Gastroesophageal variceal bleeding is a life-threatening complication in patients with liver cirrhosis and portal hypertension. The endoscopic injection of cyanoacrylate is considered as the first-line alternative for gastric varices treatment; however, the incidence of adverse events supports the endoscopic ultrasound–guided approach. Endoscopic ultrasound–guided interventions are a safe and feasible technique for the injection of sclerosants, cyanoacrylate, thrombin, and the deployment of coils into targeted vessels. This review article aims to offer an overview of the role of endoscopic ultrasound–guided vascular therapy and present the available data regarding endoscopic ultrasound–guided management of gastrointestinal bleeding and other vascular therapies. The available data have shown the superiority of endoscopic ultrasound–guided endovascular therapy over the endoscopic technique, which supports the implementation of endoscopic ultrasound–guided therapy in therapeutical algorithms and guidelines. Regarding whether injecting cyanoacrylate, the deployment of coils, or combined therapy, we recommend the endoscopic ultrasound–guided combined therapy in patients with gastric varices due to the high eradication rate with lower rebleeding and reintervention rates. Multicenter worldwide studies are required to confirm the actual clinical applicability of endoscopic ultrasound–guided endovascular therapy and establish treatment algorithms. Endoscopic ultrasound offered a safe and effective alternative in the management of variceal and nonvariceal gastrointestinal bleeding, with the implementation of new diagnostic and treatment options for various gastrointestinal conditions, representing a new territory for research and development.

Endoscopic Ultrasound-Guided Interventions for the Measurement and Treatment of Portal Hypertension

The number of endoscopic ultrasound (EUS)-guided interventions is rapidly growing within advanced endoscopy. EUS offers high-resolution imaging of mediastinal and intra-abdominal vasculature, which can be targeted for various interventions, hence a growing number of studies have explored EUS-guided vascular catheterization. Potential clinical applications of EUS-guided portal venous access include angiography, measurement of the portosystemic pressure gradient, and EUS-guided transhepatic intrahepatic portosystemic shunt creation. This article reviews different devices and techniques used in these applications.

Endoscopic Ultrasound-Guided Portal Pressure Measurement and Interventions

A growing number of studies have explored endoscopic ultrasound (EUS)-guided vascular catheterization. Potential clinical applications of EUS-guided portal venous access include angiography, measurement of the portosystemic pressure gradient, EUS-guided transhepatic intrahepatic portosystemic shunt creation and portal vein sampling for the evaluation in gastrointestinal cancer. The following article reviews the different devices and techniques employed in these applications.

Endoscopic Ultrasound-Guided Vascular Interventions: From Diagnosis to Treatment

The development of endoscopic ultrasound was driven by the need to develop less invasive alternatives to surgical and radiologic interventions for a wide variety of gastrointestinal conditions. During the past decade, there has been a very rapid growth in the clinical role and capabilities of endoscopic ultrasound-guided therapeutic interventions. Endoscopic ultrasound offers both real-time imaging and access to structures within and adjacent to the gastrointestinal tract. The proximity of the gastrointestinal system to vascular structures throughout the abdomen and the mediastinum allows for endoscopic ultrasound-guided vascular access and therapy. The recent development of endoscopic ultrasound-guided vascular interventions has relied both on finding new applications for standard endoscopic accessories and on commandeering tools originally developed for use in interventional radiology. This article provides a review of the literature regarding the current state of endoscopic ultrasound for the management of variceal and nonvariceal bleeding, portal vein angiography and pressure measurements, intrahepatic portosystemic shunts, endoscopic ultrasound-guided fine-needle aspiration for portal vein sampling, drug administration and embolization as well as endoscopic ultrasound-guided cardiac access and treatment.

Feasibility and safety of EUS-guided selective portal vein embolization with a coil and cyanoacrylate in a live porcine model

Background and Objectives:

Preoperative portal vein (PV) embolization using the percutaneous transhepatic approach has been performed in patients with hepatobiliary malignancy before extensive liver resection. The aim of this study is to evaluate the technical feasibility and initial safety of EUS-guided selective PV embolization using a coil and cyanoacrylate in a live porcine model.

Methods:

EUS-guided selective intrahepatic PV embolization with a coil and cyanoacrylate was performed in 9 pigs. The selected PV was punctured with 19G fine-needle aspiration (FNA) needle, and the coil was inserted under EUS-guidance. The cyanoacrylate was then immediately injected through the same FNA needle. The blood flow change in the embolized PV was evaluated using color Doppler EUS. A necropsy was performed following the 1-week observation period.

Results:

The success rates for the coil and cyanoacrylate delivery were 88.9% (8/9) and 87.5% (7/8), respectively. In 1 case, the coil migrated into the hepatic parenchyma. In another case, the cyanoacrylate injection failed due to early clogging in the FNA needle. There was a complete blockage of blood flow confirmed by color Doppler EUS in the embolized PV after coil and cyanoacrylate treatment. There was coil migration into the hepatic parenchyma in 1 case. There was no animal distress observed during the 1-week observation period before necropsy. The necropsy showed no evidence of damage to the intra-abdominal organs, and the selected PV was totally occluded with embolus.

Conclusion:

The study findings indicate EUS-guided selective PV embolization is both technically feasible and initially safe in an animal model.

Endoscopic Ultrasound-guided Portal Venous Access: Diagnostic and Therapeutic Implications

Endoscopic ultrasound (EUS) has evolved from a purely diagnostic to an interventional modality offering minimally invasive alternatives to surgical and radiologic interventions. This has led to a rapidly growing interest in EUS-guided vascular interventions. EUS-guided portal venous access is an emerging technique which opens a new arena for interventional vascular EUS. Portal vein can be accessed under EUS guidance with high precision and low risk of complications thus expanding its application for both benign and malignant conditions. Potential applications of EUS-guided portal vein access include: fine needle aspiration of portal vein thrombus and portal venous blood sampling for circulating tumor cells for diagnosis and staging of occult and known malignancies; portal vein angiography, portal pressure measurement, and creation of endoscopic intrahepatic portosystemic shunt; portal vein embolization and targeted drug delivery. This article will review the current literature on EUS-guided portal vein access, its feasibility and safety in animal and human studies, and current diagnostic and therapeutic applications with future directions.

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 Ultrasound-Guided Vascular Therapy: The Present and the Future

Endoscopic ultrasound (EUS) offers access to many intra-abdominal vessels that until now have only been accessible to the surgeon and interventional radiologist. In addition to assisting with diagnostics, this unique access offers the potential for therapeutic intervention for a host of indications. To date, this has had the most clinical impact in the treatment of gastroesophageal varices, with EUS-guided coil and glue application growing in use worldwide. Although randomised controlled trial data is lacking, we discuss the growing body of literature behind EUS-guided therapy in the management of varices. EUS has also been used in specialized centres to assist in non-variceal gastrointestinal bleeding. The treatment of bleeding from Dieulafoy lesions, tumours and pancreatic pseudoaneurysms has all been described. The potential applications of EUS have also extended to the placement of portal vein stents and porto-systemic shunts in animal models. As medicine continues to move to increasingly less invasive interventions, EUS-guided therapies offer substantial promise for the safe and effective delivery of targeted treatment for a widening array of vascular disorders.

EUS-guided intrahepatic portosystemic shunt with direct portal pressure measurements: a novel alternative to transjugular intrahepatic portosystemic shunting

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic shunting involves the creation of a low-resistance channel between the portal vein (PV) and the hepatic vein (HV), and is routinely performed under angiography. The aims were to evaluate (1) safety and technical feasibility; (2) procedural duration; and (3) subjective workload assessment of EUS-guided intrahepatic portosystemic shunt (EIPS).

METHODS

Five Yorkshire pigs were used in the study. The HV or inferior vena cava (IVC) was identified using a linear-array echoendoscope and accessed with a 19-G FNA needle preloaded with a digital pressure wire. Mean pressure was recorded. The needle was advanced into the PV, where pressure measurements were again taken, and ultimately exchanged over a guidewire. A lumen-apposing metal stent was deployed under EUS and fluoroscopic guidance, with distal and proximal ends positioned inside the PV and HV (IVC), respectively. Dilation was performed, and pressure measurements repeated. The National Aeronautics and Space Administration (NASA) Task Load Index (TLI) was scored. Animals survived 2 weeks before necropsy.

RESULTS

EIPS was successful in 5 out of 5 pigs. Mean time required for EUS identification, needle access, pressure measurement, and stent placement was 43 (31-55) minutes. NASA TLI scores revealed moderate workload. Mean baseline pressure measurements were PV 7.0 (5-9) and HV/IVC 5.0 (3-7) mm Hg and PV 6.3 (5-7) and HV/IVC 6.0 (4-7) mm Hg after. All animals survived 2 weeks. No bleeding was seen on necropsy.

CONCLUSIONS

This study demonstrates the technical feasibility of EIPS using LAMS, with direct portal pressure measurement, in a survival model. In addition, the procedure was performed quickly with moderate technical demand.

Interventional endoscopic ultrasound: A new promising way for intrahepatic portosystemic shunt with portal pressure gradient

Background and Objectives:

Interventional endoscopic ultrasound (EUS) is a promising novel approach for intravascular interventions. The aim of this study was to assess the feasibility and safety of a EUS-guided intrahepatic portosystemic shunt (EGIPS) with portal pressure gradient measurement in a live porcine model.

Methods:

The left hepatic vein (LHV) or the inferior vena cava (IVC) was punctured with a needle that advanced into the portal vein (PV). A guidewire was then inserted into the PV, and a needle knife was used to create an intrahepatic fistula between LHV and PV. Portal pressure was recorded. The fistula was dilated with a balloon and a biliary metal stent was deployed between LHV and PV under sonographic and fluoroscopic observation. A portocavography validated the patency of the stent. Necropsies were realized after euthanasia.

Results:

Portosystemic stenting was achieved in 19/21 pigs. Final portocavography confirmed stent patency between PV and LHV or IVC in 17 pigs (efficacy of 81%): Four stents were dysfunctional as two were thrombosed and two were poor positioned. Portal pressure was documented before and after shunting in 20/21 pigs. Necropsies revealed that 19/21 procedures were transesophageal and two were transgastric. Hemoperitoneum and pneumothorax were found in one pig and hemothorax was found in two pigs. Morbidity was 14.2% (3/21 animals).

Conclusion:

EGIPS was feasible in 91% of cases, functional in 81%, with 14.2% per procedure morbidity. EGIPS still needs to be assessed in portal hypertension pig models with longer follow-up before being considered as an alternative when the transjugular intrahepatic portosystemic shunt fails.

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.

EUS-guided portal pressure gradient measurement with a novel 25-gauge needle device versus standard transjugular approach: a comparison animal study

BACKGROUND AND AIMS

Portal hypertension (PH) is a serious adverse event of liver cirrhosis. The hepatic venous pressure gradient (HVPG) accurately reflects the degree of PH and is the single best prognostic factor in liver disease. Currently, portal pressure gradient (PPG) measurement is performed at interventional radiology (IR) with a standard transjugular approach requiring radiation and intravenous contrast. The aim of this study was to develop a novel EUS-guided system using a 25G FNA needle and compact manometer to directly measure PPG and to evaluate its performance and clinical feasibility.

METHODS

Experiments were performed in 3 swine that were under general anesthesia. Manometry was performed in venous (baseline and PH) and arterial (aorta) systems. The PH model was created by rapid Dextran-40 infusion peripherally. Under EUS guidance a 25G FNA needle with attached manometer was used to puncture (transgastric-transhepatic approach) and measure pressures in the portal vein, right hepatic vein (RHV), inferior vena cava (IVC), and aorta. With the IR approach, RHV (free and wedged), IVC, and aorta pressure were measured with an occlusion balloon. Pressure correlation was divided into 3 groups; low pressure (baseline), medium pressure (noncirrhotic portal hypertensive model), and high pressure (arterial). Correlation between the 2 methods of measurement was charted in scatter plots, and the Pearson's correlation coefficient (R) was calculated.

RESULTS

EUS identification, access, and manometry was successful in all targeted vessels. There was excellent correlation (R, .985-.99) between EUS and IR methods in all pressure ranges. No adverse event occurred.

CONCLUSIONS

This novel technique of EUS-PPG measurement using a 25G needle and novel manometer was feasible and demonstrated excellent correlation with the standard transjugular method throughout low, medium, and high pressure ranges.

Endoscopic ultrasound-guided interventions in special situations

Endoscopic ultrasound (EUS) was introduced in 1982 and has since become a popular advanced procedure for diagnosis and therapeutic intervention. Initially, EUS was most commonly used for the diagnosis of pancreatobiliary diseases and tissue acquisition. EUS was first used for guided cholangiography in 1996, followed by EUS-guided biliary drainage in 2001. Advancements in equipment and endoscopic accessories have led to an expansion of EUS-guided procedures, which now include EUS-guided drainage of intra-abdominal abscesses or collections, intra-vascular treatment of refractory variceal and nonvariceal bleeding, transmural pancreatic drainage, common bile duct stone clearance, enteral feeding tube placement and entero-enteric anastomosis. Patients with surgically altered upper gastrointestinal anatomies have greatly benefited from EUS also. This systematic review describes and discusses EUS procedures performed in uncommon diseases and conditions, as well as applications on more vulnerable patients such as young children and pregnant women. In these cases, routine approaches do not always apply, and thus may require the use of innovative and unconventional techniques. Increased knowledge of such special applications will help increase the success rates of these procedures and provide a foundation for additional advances and utilizations of the technique.

Endoscopic ultrasonography-guided placement of a transhepatic portal vein stent in a live porcine model

Background and Objectives:

Percutaneous portal vein (PV) stent placement is used to manage PV occlusion or stenosis caused by malignancy. The use of endoscopic ultrasonography (EUS) has expanded to include vascular interventions. The aim of this study was to examine the technical feasibility and safety of EUS-guided transhepatic PV stent placement in a live porcine model.

Materials and Methods:

EUS-guided transhepatic PV stent placement was performed in six male miniature pigs under general anesthesia using forward-viewing echoendoscope. Under EUS guidance, the left intrahepatic PV was punctured with a 19-gauge fine-needle aspiration (FNA) needle and a 0.025 inch guidewire inserted through the needle and into the main PV. The FNA needle was then withdrawn and a needle-knife inserted to dilate the tract. Under EUS and fluoroscopic guidance, a noncovered metal stent was inserted over the guidewire and released into the main PV.

Results:

A PV stent was placed successfully in all six pigs with no technical problems or complications. The patency of the stent in the main PV was confirmed using color Doppler EUS and transhepatic portal venography. Necropsy of the first three animals revealed no evidence of bleeding and damage to intra-abdominal organs or vessels. No complications occurred in the remaining three animals during the 8 weeks observation period.

Conclusions:

EUS-guided transhepatic PV stent placement can be both technically feasible and safe in a live animal model.

Hepatic applications of endoscopic ultrasound: Current status and future directions

The diagnosis and staging of various gastrointestinal malignancies have been made possible with the use of endoscopic ultrasound, which is a relatively safe procedure. The field of endoscopic ultrasound is fast expanding due to advancements in therapeutic endoscopic ultrasound. Though various studies have established its role in gastrointestinal malignancies and pancreatic conditions, its potential in the field of hepatic lesions still remains vastly untapped. In this paper the authors attempt to review important and landmark trials, case series and case studies involving hepatic applications of endoscopic ultrasound, thus not only providing an overview of utilization of endoscopic ultrasound in various liver conditions but also speculating its future role.

Endoscopic ultrasound guided vascular access and therapy (with videos)

The continued need to develop minimally invasive alternatives to surgical and radiologic interventions has driven the development of endoscopic ultrasound (EUS)-guided treatments. EUS has now stepped into the therapeutic arena. EUS provides the unique advantage of both real-time imaging and access to structures within and adjacent to the gastrointestinal (GI) tract. Hence, EUS-guided therapeutic techniques continue to evolve in several directions enabling a variety of minimally invasive therapies for pancreatic and biliary pathologies. Furthermore, the close proximity of the GI tract to vascular structures in the mediastinum and abdomen permits EUS-guided vascular access and therapy. Studies have demonstrated several EUS-guided vascular interventions by using standard endoscopic accessories and available tools from the interventional radiology armamentarium. This article provides an overview of the literature including clinical and nonclinical studies for the management of nonvariceal and variceal GI bleeding, formation of intrahepatic portosystemic shunts (IPSS), and EUS-guided cardiac access and therapy.

Learning models for endoscopic ultrasonography in gastrointestinal endoscopy

Endoscopic ultrasonography (EUS) has become a useful diagnostic and therapeutic modality in gastrointestinal endoscopy. However, EUS requires additional training since it requires simultaneous endoscopic manipulation and ultrasonographic interpretation. Obtaining adequate EUS training can be challenging since EUS is highly operator-dependent and training on actual patients can be associated with an increased risk of complications including inaccurate diagnosis. Therefore, several models have been developed to help facilitate training of EUS. The models currently available for EUS training include computer-based simulators, phantoms, ex vivo models, and live animal models. Although each model has its own merits and limitations, the value of these different models is rather complementary than competitive. However, there is a lack of objective data regarding the efficacy of each model with recommendations on the use of various training models based on expert opinion only. Therefore, objective studies evaluating the efficacy of various EUS training models on technical and clinical outcomes are still needed.

Endoscopic ultrasound-guided intravascular therapy

The gastrointestinal tract provides a unique "window" to access vascular structures in the mediastinum and abdomen. The advent of interventional endoscopic ultrasound (EUS) has enabled access to these structures with a standard fine-needle aspiration (FNA) needle. Sclerosants, cyanoacrylate, and coils can be delivered through the lumen of the FNA needle. EUS-guided treatment of gastric varices has theoretical advantages over conventional endoscopy-guided treatment. Controlled studies are needed to determine the role of EUS-guided treatment for primary and secondary prevention of variceal bleeding. There is a growing list of novel indications for EUS-guided vascular therapy that include portal vein angiography and pressure measurements, intrahepatic portosystemic shunt placement, and micro coil embolization of vascular structures. Additionally, access and therapy of the heart and surrounding structures appears feasible.

Utility of endoscopic ultrasound in patients with portal hypertension

Endoscopic ultrasound (EUS) has revolutionized the diagnostic and therapeutic approach to patients with gastrointestinal disorders. Its application in patients with liver disease and portal hypertension is increasing. Patients with chronic liver disease are at risk for development of portal hypertension sequale such as ascites, spontaneous bacterial peritonitis and gastroesophageal varices. Bleeding esophageal and gastric varices are among the most common causes of mortality in patients with cirrhosis. Thus, early detection and treatment improve the outcome in this population. EUS can improve the detection and diagnosis of gastroesophageal varices and collateral veins and can provide endoscopic therapy of gastroesophageal varices such as EUS-guided sclerotherapy of esophageal collateral vessels and EUS-guided cynoacrylate (Glue) injection of gastric varices. EUS can also provide knowledge on the efficacy of pharmacotherapy of portal hypertension. Furthermore, EUS can provide assessment and prediction of variceal recurrence after endoscopic therapy and assessment of portal hemodynamics such as E-Flow and Doppler study of the azygous and portal veins. Moreover, EUS-guided fine needle aspiration may provide cytologic diagnosis of focal hepatic tumors and analysis of free abdominal fluid. Using specialized EUS-guided needle biopsy, a sample of liver tissue can be obtained to diagnose and evaluate for chronic liver disease. EUS-guided fine needle injection can be used to study portal vein pressure and hemodynamics, and potentially could be used to assist in exact measurement of portal vein pressure and placement of intrahepatic portosystemic shunt.

Endoscopic Ultrasound-Guided Treatment beyond Drainage: Hemostasis, Anastomosis, and Others

Since the introduction of endoscopic ultrasound (EUS) in the 1990s, it has evolved from a primarily diagnostic modality into an instrument that can be used in various therapeutic interventions. EUS-guided fine-needle injection was initially described for celiac plexus neurolysis. By using the fundamentals of this method, drainage techniques emerged for the biliary and pancreatic ducts, fluid collections, and abscesses. More recently, EUS has been used for ablative techniques and injection therapies for patients with for gastrointestinal malignancies. As the search for minimally invasive techniques continued, EUS-guided hemostasis methods have also been described. The technical advances in EUS-guided therapies may appear to be limitless; however, in many instances, these procedures have been described only in small case series. More data are required to determine the efficacy and safety of these techniques, and new accessories will be needed to facilitate their implementation into practice.

Endoscopic ultrasound description of liver segmentation and anatomy

Endoscopic ultrasound (EUS) can demonstrate the detailed anatomy of the liver from the transgastric and transduodenal routes. Most of the liver segments can be imaged with EUS, except the right posterior segments. The intrahepatic vascular landmarks include the major hepatic veins, portal vein radicals, hepatic arterial branches, and the inferior vena cava, and the venosum and teres ligaments are other important intrahepatic landmarks. The liver hilum and gallbladder serve as useful surface landmarks. Deciphering liver segmentation and anatomy by EUS requires orienting the scan planes with these landmarkstructures, and is different from the static cross-sectional radiological images. Orientation during EUS requires appreciation of the numerous scan planes possible in real-time, and the direction of scanning from the stomach and duodenal bulb. We describe EUS imaging of the liver with a curved linear probe in a step-by-step approach, with the relevant anatomical details, potential applications, and pitfalls of this novel EUS application.

EUS-Guided Vascular Procedures: A Literature Review

Endoscopic ultrasound (EUS) is continuously stepping into the therapeutic arena, simultaneously evolving in different directions, such as the management of pancreatic and biliary diseases, celiac neurolysis, delivering local intratumoral therapy, and EUS-guided endosurgery. EUS-guided vascular procedures are also challenging, considering the variety of vascular pathology, proximity of the vascular structures to the GI tract wall, high resolution, and real-time guidance offering an attractive access route and precise delivery of the intervention. The literature on vascular therapeutic EUS demonstrates techniques for the management of upper GI variceal and nonvariceal bleeding, pseudoaneurysms, and coiling and embolization procedures, as well as the creation of intrahepatic portosystemic shunts. The paucity of studies, diversity of study designs, and the number of animal model studies hamper a systematic approach to the conclusion and decision making important to clinicians and healthcare policy makers. Nevertheless, theoretical benefits and findings up to date concerning technical feasibility, efficacy, and safety of the procedures drive further research and development in this rather young therapeutic arena.

EUS-guided vascular access and therapy

The gastrointestinal tract provides a unique window to access vascular structures in the mediastinum and abdomen. The advent of interventional endoscopic ultrasound (EUS) has enabled access to these structures with standard fine-needle aspiration. EUS-guided treatment of varices has been largely reserved as rescue therapy for refractory bleeding but has theoretic advantages over conventional endoscopy-guided treatment. Data are limited and multicenter, prospective controlled trials are needed to show clinical effectiveness and safety in humans. The development of new tools designed for EUS-guided vascular therapy is needed.