EUS-derived criteria for distinguishing benign from malignant metastatic solid hepatic masses

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 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.

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.

Prospective Study Assessing Impact of Ethylene Oxide Sterilization on Endoscopic Ultrasound Image Quality

BACKGROUND & AIMS

Duodenoscope-associated transmission of infections has raised questions about efficacy of endoscope reprocessing using high-level disinfection (HLD). Although ethylene oxide (ETO) gas sterilization is effective in eradicating microbes, the impact of ETO on endoscopic ultrasound (EUS) imaging equipment remains unknown. In this study, we aimed to compare the changes in EUS image quality associated with HLD vs HLD followed by ETO sterilization.

METHODS

Four new EUS instruments were assigned to 2 groups: Group 1 (HLD) and Group 2 (HLD + ETO). The echoendoscopes were assessed at baseline, monthly for 6 months, and once every 3 to 4 months thereafter, for a total of 12 time points. At each time point, review of EUS video and still image quality was performed by an expert panel of reviewers along with phantom-based objective testing. Linear mixed effects models were used to assess whether the modality of reprocessing impacted image and video quality.

RESULTS

For clinical testing, mixed linear models showed minimal quantitative differences in linear analog score (P = .04; estimated change, 3.12; scale, 0-100) and overall image quality value (P = .007; estimated change, -0.12; scale, 1-5) favoring ETO but not for rank value (P = .06). On phantom testing, maximum depth of penetration was lower for ETO endoscopes (P < .001; change in depth, 0.49 cm).

CONCLUSIONS

In this prospective study, expert review and phantom-based testing demonstrated minimal differences in image quality between echoendoscopes reprocessed using HLD vs ETO + HLD over 2 years of clinical use. Further studies are warranted to assess the long-term clinical impact of these findings. In the interim, these results support use of ETO sterilization of EUS instruments if deemed clinically necessary.

Value of contrast-enhanced harmonic endoscopic ultrasound for diagnosing hepatic metastases of pancreatic cancer: A prospective study

BACKGROUND AND AIMS

This study aimed to compare contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) with fundamental B-mode endoscopic ultrasonography (EUS) and contrast-enhanced computed tomography (CE-CT) for the diagnosis of left hepatic lobe metastases of pancreatic adenocarcinoma.

METHODS

In this single-center prospective study, CE-CT, EUS, and CH-EUS were performed to detect left hepatic lobe metastases in patients with pancreatic adenocarcinoma, and the detection rates were compared between EUS plus CH-EUS and the other two modalities. Subgroup comparisons of between-modality detection rate were performed in patients with only metastases of <10 mm. The number of pancreatic adenocarcinoma patients whose clinical stage and treatment strategy were changed because of EUS plus CH-EUS findings was also assessed.

RESULTS

Thirty-one patients were diagnosed with left hepatic lobe metastases. For overall detection of left hepatic lobe metastases, EUS plus CH-EUS had significantly higher accuracy (94.3%) than CE-CT (86.7%) and EUS alone (87.6%) (P = 0.021 and P = 0.020, respectively). For detection of left hepatic lobe metastases < 10 mm, EUS plus CH-EUS (93.3%) was significantly superior to CE-CT (84.4%) and EUS alone (85.6%) (P = 0.021 and P = 0.020, respectively). In five of the 11 patients in whom only CH-EUS allowed detection of hepatic metastases, the stage and/or treatment strategy of the pancreatic adenocarcinoma was changed after CH-EUS.

CONCLUSION

This study demonstrated that EUS plus CH-EUS has advantages over CE-CT and EUS alone with regard to the accuracy of detecting left hepatic lobe metastases, particularly small hepatic metastases and accurate staging.

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 for Detection of Liver Metastasis: Hope or Hype?

Transabdominal ultrasonography, contrast-enhanced computed tomography, and magnetic resonance imaging (MRI) are the common diagnostic tests for the detection of hepatic lesions. Use of enhanced and advanced MRI technique, that is, diffusion weighted MRI and hepatocyte-specific contrast agents, has further improved the accuracy of detection of metastatic liver lesions ≤10 mm in diameter. However, even with these advanced imaging modalities sensitivity is low for lesions smaller than 10 mm when compared with standard intraoperative ultrasound. Endoscopic ultrasound (EUS) is an emerging imaging modality with resolution sufficient to detect and sample lesions as small as 5 mm in diameter. In this news and views, we have discussed the role of standard and enhanced EUS for the detection of metastatic liver lesions.

The Asian Federation of Societies for Ultrasound in Medicine and Biology (AFSUMB) Guidelines for Contrast-Enhanced Endoscopic Ultrasound

The Asian Federation of Societies for Ultrasound in Medicine and Biology aimed to provide information on techniques and indications for contrast-enhanced harmonic endoscopic ultrasound (CH-EUS), and to create statements including the level of recommendation. These statements are based on current scientific evidence reviewed by a Consensus Panel of 15 internationally renowned experts. The reliability of clinical questions was measured by agreement rates after voting. Six statements were made on techniques, including suitable contrast agents for CH-EUS, differences between contrast agents, setting of mechanical index, dual imaging and duration and phases for observation. Thirteen statements were made on indications, including pancreatic solid masses, pancreatic cancer staging, pancreatic cystic lesions and mural nodules, detection of subtle pancreatic lesions, gallbladder sludge and polyps, hepatic lesions, lymph nodes, subepithelial lesions, visceral vascular diseases, guidance of fine needle aspiration and evaluation for local therapy. These international expert consensus guidelines will assist endosonographers in conducting CH-EUS according to evidence-based information.

Application of artificial intelligence using a novel EUS-based convolutional neural network model to identify and distinguish benign and malignant hepatic masses

BACKGROUND AND AIMS

Detection and characterization of focal liver lesions (FLLs) is key for optimizing treatment for patients who may have a primary hepatic cancer or metastatic disease to the liver. This is the first study to develop an EUS-based convolutional neural network (CNN) model for the purpose of identifying and classifying FLLs.

METHODS

A prospective EUS database comprising cases of FLLs visualized and sampled via EUS was reviewed. Relevant still images and videos of liver parenchyma and FLLs were extracted. Patient data were then randomly distributed for the purpose of CNN model training and testing. Once a final model was created, occlusion heatmap analysis was performed to assess the ability of the EUS-CNN model to autonomously identify FLLs. The performance of the EUS-CNN for differentiating benign and malignant FLLs was also analyzed.

RESULTS

A total of 210,685 unique EUS images from 256 patients were used to train, validate, and test the CNN model. Occlusion heatmap analyses demonstrated that the EUS-CNN model was successful in autonomously locating FLLs in 92.0% of EUS video assets. When evaluating any random still image extracted from videos or physician-captured images, the CNN model was 90% sensitive and 71% specific (area under the receiver operating characteristic [AUROC], 0.861) for classifying malignant FLLs. When evaluating full-length video assets, the EUS-CNN model was 100% sensitive and 80% specific (AUROC, 0.904) for classifying malignant FLLs.

CONCLUSIONS

This study demonstrated the capability of an EUS-CNN model to autonomously identify FLLs and to accurately classify them as either malignant or benign lesions.

Improved detection of liver metastasis using Kupffer-phase imaging in contrast-enhanced harmonic EUS in patients with pancreatic cancer (with video)

BACKGROUND AND AIMS

Kupffer-phase imaging visualized by perfluorobutane (Sonazoid) distribution into normal liver tissues upon phagocytosis by Kupffer cells potentially aids in improving detection of liver metastasis compared with fundamental B-mode EUS (FB-EUS). However, the diagnostic performance of Kupffer-phase imaging in contrast-enhanced harmonic EUS (CH-EUS) remains unclear. Hence, this study aimed to evaluate the usefulness of CH-EUS-based Kupffer-phase imaging for diagnosing liver metastasis from pancreatic cancer.

METHODS

We retrospectively analyzed consecutive patients with pancreatic cancer who underwent contrast-enhanced CT (CE-CT) and FB-EUS, followed by CH-EUS, from 2011 to 2017. The diagnostic ability of CH-EUS against that of CE-CT and FB-EUS for metastasis in the left liver lobe was compared. Subsequently, the influences of CH-EUS on the determination of clinical stage and patient management for pancreatic cancer were assessed.

RESULTS

We enrolled 426 patients with pancreatic cancer. Metastasis in the left liver lobe was present in 27.2% of patients. The diagnostic accuracy of CE-CT, FB-EUS, and CH-EUS was 90.6%, 93.4%, and 98.4%, respectively. The sensitivity and diagnostic accuracy of CH-EUS for metastasis in the left liver lobe were significantly higher than those of FB-EUS or CE-CT. The sensitivity of CH-EUS for detecting small liver metastasis (<10 mm) was considerably higher than that of CE-CT or FB-EUS (P < .001). In 2.1% of patients, only CH-EUS could detect a single distant metastasis of the left liver lobe, thereby upgrading the tumor staging and altering the clinical management.

CONCLUSIONS

CH-EUS-based Kupffer-phase imaging increased the detectability of metastasis in the left liver lobe. This technique could be a reliable pretreatment imaging modality for clinical decision-making in patients with pancreatic cancer.

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.

Practical approach to linear EUS examination of the liver

EUS has become a substantial diagnostic and therapeutic modality for digestive tract conditions. The extent of endosonographic assessment is wide, and, among others, it allows for the evaluation of liver anatomy and related pathologies. Moreover, EUS assessment has proved more accurate in detecting small focal liver lesions missed by standard imaging examinations such as computed tomography or magnetic resonance. Endosonographically, various liver segments can be visualized by transgastric and transduodenal scanning following anatomical landmarks, thus providing arranged systematic examination. In addition, knowledge considering the correct position during examination is crucial for EUS-guided procedures such as hepaticogastrostomy, ablation of tumors, and measurement of portal pressure gradient. The evolution of EUS-guided intervention has contributed to the increasing importance of understanding the hepatic segmental anatomy during the EUS examination.

Endoscopic Ultrasound-Guided Fine Needle Aspiration Using a 22-G Needle for Hepatic Lesions: Single-Center Experience

BACKGROUND/AIMS

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been accepted as a reliable tool in diagnosing and staging intra-abdominal tumors. In this study, we aimed to investigate the performance of EUS-FNA in the evaluation of liver masses and its impact on patient management and procedure-related complications retrospectively.

METHODS

Data of patients who underwent EUS-FNA biopsies due to liver masses between November 2017 and July 2018 were retrieved retrospectively. Biopsies were performed using 22-G needles. The demographics, EUS-FNA results, sensitivity and specificity of the procedure, negative predictive value, positive predictive value, and specimen sufficiency rates were assessed.

RESULTS

A total of 25 patients (10 females) were included in the study. The mean age was 62.73±15.2 years. The mean size of the masses was 34.50±16.04 mm. The technical success rate was 88%. During the EUS-FNA procedure, each patient had only one pass with 94.45% of aspirate sufficiency rate and 86.3% of biopsy sufficiency rate. The diagnostic accuracy rate was 86.3%. There were no complications.

CONCLUSION

For the evaluation of liver masses, EUS-FNA using a 22-G needle with even one pass had high aspiration and biopsy success rates accompanied with high diagnostic accuracy rates.

A Comprehensive Narrative Review on the Evolving Role of Endoscopic Ultrasound in Focal Solid Liver Lesions Diagnosis and Management

The implications of endoscopic ultrasound (EUS) have expanded considerably in recent years to cover more fields in invasive gastroenterology practice, as both an investigative and therapeutic modality. The utility of EUS in the diagnosis and management of focal liver lesions has gained a special attractiveness recently. The EUS probe proximity to the liver and its excellent spatial resolution enables real-time images coupled with several enhancement techniques, such as contrast-enhanced (CE) EUS. Aside from its notable capability to execute targeted biopsies and therapeutic interventions, EUS has developed into a hopeful therapeutic tool for the management of solid liver lesions. Herein, we provide a comprehensive state-of-the-art review on the efficacy and safety of EUS in the diagnosis and management of focal solid liver lesions. Medline/PubMed and Embase database searches were conducted by two separate authors (T.K. and W.S.), all relevant studies were assessed, and relevant data was extracted and fully reported. EUS-guided diagnosis of focal liver lesions by sonographic morphologic appearance and cytological and histopathological finding of biopsies obtained via fine needle aspiration/biopsy have been shown to significantly improve the diagnosis of solid liver lesions compared with traditional imaging tools. Similarly, EUS-guided treatment has been shown to consistently have excellent technical success, high efficacy, and minor adverse events. The evolving valuable evidences of EUS utility might satisfy the unmet need of optimizing management of focal solid liver lesions.

Endoscopic ultrasound in chronic liver disease

Endoscopic ultrasound (EUS) is a minimally invasive diagnostic and therapeutic modality with a number of established as well as evolving uses in patients with chronic liver disease. Compared to other diagnostic tools such as cross-sectional imaging or conventional endoscopy, EUS has been shown to increase diagnostic sensitivity and therapeutic success for many clinical scenarios and applications with a low rate of adverse events. In this review, we discuss and focus on the current and growing role of EUS in the evaluation and/or treatment of hepatobiliary masses, hepatic parenchymal disease, portal hypertension, esophageal and other varices, and indeterminate biliary strictures.

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.

Endoscopic Ultrasound for the Diagnosis and Staging of Liver Tumors

Endoscopic ultrasound examination may provide complementary information to cross-sectional imaging in lesions of the liver, portal vein, and surrounding lymph nodes. With fine needle aspiration, endoscopic ultrasound examination is a powerful tool for the diagnosis of focal liver lesions and has usefulness in the evaluation of indeterminate liver lesions. Endoscopic ultrasound examination may influence hepatocellular cancer staging and Endoscopic ultrasound examination with fine needle aspiration of locoregional nodes and portal vein thromboses changes management. Contrast-enhanced endoscopic ultrasound examination and endoscopic ultrasound examination elastography are likely to expand the usefulness of endoscopic ultrasound examination in evaluating liver malignancy with technologic improvements.

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.

Accuracy of Endoscopic Ultrasound Imaging in Distinguishing Celiac Ganglia From Celiac Lymph Nodes

BACKGROUND & AIMS

Endoscopic ultrasound (EUS) allows visualization of celiac lymph nodes (CLNs) and celiac ganglia (CG). Reliably distinguishing these structures is important for tumor staging and CG ablative therapies. We aimed to evaluate the accuracy of EUS in distinguishing CLNs from CG using a strict cytopathology reference standard. We also determined the rate of detection of CLN and CG by conventional cross-sectional imaging.

METHODS

From EUS and cytopathology databases, we identified all patients who underwent EUS-FNA of a presumed CLN or CG from October 1, 2004, through March 1, 2017, and compared the findings with those from cytology (reference standard). Indeterminate cytology results were re-reviewed. EUS imaging (ie, index test) results were compared with those from the reference standard. An expert radiologist re-reviewed computed tomography and magnetic resonance images from 100 lesions, from 94 randomly selected patients with a reference standard, to determine the rates of CLN and CG detection.

RESULTS

A total of 504 patients (mean age, 63.4 ± 13.2 years; 292 men) underwent a median of 7 EUS-FNA passes (range, 1-13) for a total of 566 lesions perceived to be either a CLN or CG; the cytology reference standard was available for 521 lesions (92.1%). When we excluded indeterminate cytology results, the EUS accurately identified 281/286 CLNs (98.3%) and 166/186 CGs (89.2%), for an overall accuracy of 447/472 (94.7%). EUS-FNA distinguished CG from CLNs with a 93.3% sensitivity, 93.7% specificity, a positive predictive value of 96.2%, and a negative predictive value of 89.2%. Of 100 lesions in 94 patients randomly selected for a second expert radiology review, computed tomography and magnetic resonance imaging detected 59/67 CLNs (88.1%) and 13/33 CG (39.4%).

CONCLUSION

EUS accurately distinguishes CLNs from CG. EUS might therefore be used to increase the accuracy of tumor staging, to select tumor stage-appropriate therapy, and to guide CG-ablative therapies.

EUS liver assessment using contrast agents and elastography

Transabdominal-US is the first-line imaging modality used to assess the whole liver parenchyma and vascularization; EUS assessment of the liver is incomplete and is not sufficient to rule out the presence of focal liver lesions. On the other hand, due the high diagnostic yield in detecting very small (< 1 cm) lesions, EUS is considered complementary to radiological imaging techniques for the investigation of liver parenchyma. Scarce data are available regarding the investigation of liver parenchyma using both EUS-elastography (EUS-E) and CH-EUS. The aim of this review is to evaluate the clinical role of image enhancement techniques, namely EUS-E and contrast harmonic-EUS (CH-EUS), for the evaluation liver diseases. Despite a potential interest for the application of EUS-E in the assessment of liver diseases, available evidence relegates this technique only to research areas, such as the differential diagnosis between benign and malignant focal liver lesions and the quantification of liver fibrosis in diffuse parenchymal diseases. With the future introduction of EUS shear-wave elastography, interesting data can be obtained for the assessment of liver fibrosis during real-time EUS evaluation. The usefulness of CH-EUS for the evaluation of liver disease is limited by the intrinsic EUS ability to explore only the left lobe and a small part of the right lobe. CH-EUS could be used to increase the diagnostic ability of EUS for the detection and characterization of small lesions and for guiding tissue sampling. Targeting EUS-guided treatments with either EUS-E or CH-EUS might represent potential future applications.

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.