Usefulness of endoscopic ultrasonography in hepatology

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors, the histopathology examination can assist in diagnosis, staging, prognosis, and therapeutic management strategy. Endoscopic ultrasound (EUS)-guided tissue acquisition using fine needle aspiration (FNA) or more newly fine needle biopsy (FNB) is a well-developed technique in order to evaluate and differentiate the liver masses. The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination. Therefore, malignant tumors such as hepatocarcinoma, cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma, focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition. EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA. Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously, ultrasound, computer tomography or transjugulary-guided liver biopsies. This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples. The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented. The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis, especially for those who require endoscopy.

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.

Diagnostic yield of endoscopic ultrasound-guided biopsy of focal liver lesions

Endoscopic ultrasonography (EUS) has become an indispensable method for diagnosis and therapeutic procedures in gastroenterology. As experience with this technique grows, new indications continue to emerge. Due to the vicinity of the transducer to the liver, endoscopic ultrasonography provides detailed images of the liver segments and its vascular and biliary structures. Endosonographers have made an effort to define a clinical role for endoscopic ultrasound in liver diseases; however, not much is known about endoscopic ultrasound guided fine needle aspiration (EUS-FNA) in hepatic focal lesions. This review summarizes the available evidence regarding the usefulness of endoscopic ultrasound-guided fine needle aspiration in patients with focal liver lesions.

EUS-guided thrombin injection for management of gastric fundal varices

BACKGROUND AND STUDY AIMS

Cyanoacrylate glue is recommended first-line endoscopic therapy for gastric fundal varices but it is difficult to use and carries a risk of embolization. Thrombin is preferred by many in the UK, but its effectiveness can be difficult to establish at endoscopy and the rate of re-bleeding is higher. Endoscopic ultrasound (EUS) can help assess variceal blood flow and has the potential to improve both targeting and effectiveness of injection therapy. Whereas there is already some data for its use with glue, little data currently exist in relation to its use with thrombin.

PATIENTS AND METHODS

We present a series of patients treated with EUS-guided thrombin injection over the last 4 years. Thrombin was injected under EUS guidance with the intention of obliterating flow within the fundal varices. Outcomes reviewed included whether haemostasis was achieved, the dose of thrombin required for endosonographic variceal obliteration, the incidence of re-bleeding, and procedural related adverse events.

RESULTS

Eight patients received EUS-guided thrombin: 3 with active bleeding and 5 as elective prevention. In 2/3 (66 %) patients with active bleeding haemostasis was achieved after a single dose with complete variceal obliteration. 1/3 (33 %) had no alteration in blood flow despite 10 000 IU. None of the elective prevention group had further bleeding and obliteration was observed in 4/5 (80 %). A range of 600 to 10 000 IU of thrombin was used and there were no adverse procedure-related outcomes.

CONCLUSIONS

Our results are promising and suggest that EUS-guided thrombin injection may have a role in managing bleeding from gastric fundal varices.

Utility of endoscopic ultrasound and endoscopy in diagnosis and management of hepatocellular carcinoma and its complications: What does endoscopic ultrasonography offer above and beyond conventional cross-sectional imaging?

Hepatocellular carcinoma constitutes over 90% of the primary liver tumors, the rest being cholangiocarcinoma. It has an insidious presentation, which is responsible for the delayed presentation. Hence, the management strategy relies on screening to diagnose it an early stage for curative resection and/or treatment with local ablative techniques or chemotherapy. However, even with different screening programs, more than 60% of tumors are still detected at an advanced stage, leading to an unchanged mortality rate, thereby implying a room for improvement in the screening and diagnostic process. In the last few years, there has been evolution of utility of endoscopy, specifically endoscopic ultrasonography along with Fine needle aspiration, for this purpose, which we comprehensively review in this article.

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.