Transendoscopic ultrasonography during conventional upper gastrointestinal endoscopy. Clinical evaluation of a linear 20-MHz probe system

Basic Principles and Role of Endoscopic Ultrasound in Diagnosis and Differentiation of Pancreatic Cancer from Other Pancreatic Lesions: A Comprehensive Review of Endoscopic Ultrasound for Pancreatic Cancer

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Pancreatic lesions consist of both neoplastic and non-neoplastic lesions and often pose a diagnostic and therapeutic challenge due to similar clinical and radiological features. In recent years, pancreatic lesions have been discovered more frequently as incidental findings due to the increased utilization and widespread availability of abdominal cross-sectional imaging. Therefore, it becomes imperative to establish an early and appropriate diagnosis with meticulous differentiation in an attempt to balance unnecessary treatment of benign pancreatic lesions and missing the opportunity for early intervention in malignant lesions. Endoscopic ultrasound (EUS) has become an important diagnostic modality for the identification and risk stratification of pancreatic lesions due to its ability to provide detailed imaging and acquisition of tissue samples for analysis with the help of fine-needle aspiration/biopsy. The recent development of EUS-based technology, including contrast-enhanced endoscopic ultrasound, real-time elastography-endoscopic ultrasound, miniature probe ultrasound, confocal laser endomicroscopy, and the application of artificial intelligence has significantly augmented the diagnostic accuracy of EUS as it enables better evaluation of the number, location, dimension, wall thickness, and contents of these lesions. This article provides a comprehensive overview of the role of the different types of EUS available for the diagnosis and differentiation of pancreatic cancer from other pancreatic lesions while discussing their key strengths and important limitations.

Endoscopic ultrasound for the diagnosis and treatment of primary hepatocellular carcinoma

Chronic liver disease has emerged as a significant global concern, with primary hepatocellular carcinoma (HCC) representing a critical consequence of this disease. However, early detection of HCC remains challenging in clinical practice. Recently, there has been a growing interest in applying endoscopic ultrasound (EUS) as a diagnostic tool for gastrointestinal diseases. Nevertheless, using EUS to diagnose and treat HCC is uncommon. In this review we described the diagnostic and therapeutic applications of EUS in primary HCC and evaluated its clinical significance. The diagnostic procedures primarily involve EUS-guided fine-needle biopsy or aspiration, assessment of metastatic lymph nodes and portal vein thrombosis, portal pressure monitoring, and portal vein blood collection. Treatment mainly includes EUS-guided tumor ablation, brachytherapy, injectable chemotherapy, and managing variceal hemorrhage related to portal hypertension.

Miniprobe Endoscopic Sonography for Gastrointestinal Tract Assessment: A Case Series of 1451 Procedures

Conventional endoscopic sonography has allowed precise diagnostics without disturbances, and miniprobes can be easily introduced through the biopsy channel of the endoscope. Miniprobe endoscopic sonography has many benefits compared with conventional endoscopic sonography. Although there are well-known indications for miniprobe endoscopic sonography in endoscopic digestive tract assessment, there is still a need for this method to be widely spread among physicians and commonly used by most endoscopists. The aim of this series was to describe a multicenter retrospective experience with 1451 procedures using miniprobes, presenting examples and the applicability and usefulness of this technology in the daily activities of an endoscopy department.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.

Submucosal lesions

Most of the submucosal lesions encountered on endoscopy are benign; however, the fact that some of them may be malignant considerably influences the attitude toward the whole group. This article reviews the current status of endosonography in the management of submucosal lesions and focuses on determining the risk of malignancy. The predictive value of various endoscopic ultrasonography (EUS) features and their combinations and the capabilities and limitations of EUS-guided fine needle biopsy are discussed. Other issues addressed include differentiation between extraluminal compressions and true submucosal lesions, EUS-assisted endoscopic removal of submucosal lesions, and the potential role of catheter-based endosonography in the setting of submucosal lesions. Problems related to the surveillance of patients with submucosal lesions who are not candidates for surgical treatment are outlined. An overview of the recent changes in the pathologic classification of gastrointestinal mesenchymal tumors and their impact on the role of EUS in the management of submucosal lesions is given.

Subepithelial masses of the gastrointestinal tract evaluated by endoscopic ultrasonography

OBJECTIVES

To diagnose and characterize subepithelial lesions of the gastrointestinal (GI) tract using endoscopic ultrasonography (EUS) and search for markers of malignancy in stromal cell tumors.

METHODS

Fifty-four patients with suspected subepithelial lesions at endoscopy were examined using miniature ultrasound probes, integrated ultrasound endoscopes, or both. Surgical treatment was considered if a solid lesion had a maximum diameter of at least 3 cm, mixed echogenicity, or an ill-defined or irregular border.

RESULTS

EUS disclosed 37 solid lesions and ten fluid-filled structures. In seven patients, including two with protrusion from a normal spleen, no pathology could be demonstrated. Thirteen patients were operated and 41 were observed clinically with (n = 9) or without EUS (n = 32) for a median follow-up period of 36 months. Twenty-three patients had an intramural stromal cell tumor. None of these were malignant, but increased mitotic activity was found in two medium-sized resected tumors with mixed echogenicity and bleeding lesions of the endoluminal surface.

CONCLUSION

EUS can detect and characterize subepithelial masses in the GI tract. Pathologic lesions of the overlying mucosa may indicate malignant development in stromal cell tumors, but valid markers of malignant potential are still lacking.

Esophageal cancer: a systematic review

Carcinoma of the esophagus has one of the lowest possibilities of cure, with 5-year survival rates estimated to be approximately 10% overall; these rates are second only to hepatobiliary and pancreatic cancers. This fact and the rapid increase in the incidence of adenocarcinomas of the esophagus in recent years challenges us to identify areas of improvement for all aspects of this disease. We discuss potential reasons for the increase in the incidence of adenocarcinomas, evidence that defines the similarity between tumors of the gastroesophageal junction and the tubular esophagus, and other prognostic factors that may influence future modifications of our staging classification of this disease. Surgical advances have translated into improvements in surgical morbidity and mortality rates. Current therapeutic options and the relative merits of the options are discussed. Improvements in patient outcome most likely hinge on earlier diagnosis, more accurate staging, and the optimal use of combined modalities, coupled with technical advances in the modalities. A systematic review approach was undertaken to evaluate the performance characteristics of newer staging tools and the value of different combined modality approaches with particular focus on the use of those approaches for patients with potentially curable disease. A similar methodologic approach was used to address the utility of the many strategies currently used in practice for the palliation of esophageal tumors, with particular focus on the relief of malignant dysphagia. Finally, a summary of published guidelines and population-based patterns of care are presented. This serves as an overview of how all of this evidence actually translates into the care we are providing. A coordinated international effort in population-based research and randomized controlled trials would be the cornerstone to future advances in this relatively uncommon but devastating disease.

High-resolution endoluminal sonography in gastroenterology

Endosonography is an imaging method where a high frequency ultrasound probe is inserted blindly or under endoscopic control into a lumen. Examination of the gastrointestinal tract is performed using dedicated echoendoscopes or transendoscopic miniprobes. The gastrointestinal wall, mediastinum, pancreas, bile ducts, retroperitoneum, and other structures surrounding the gastrointestinal tract are target organs for endosonography. A detailed image of pathological processes can thus be obtained. The method can be used both for primary diagnosis of lesions and in follow-up of gastrointestinal diseases. It is accurate in local staging of cancer and in detecting small lesions, which cannot be seen with other imaging modalities. There are some limitations for optimal examination like stenoses or other factors prohibiting a precise position of the ultrasound transducer. The clinical importance of endosonographic examinations must be continuously evaluated on the basis of new technical modalities and changes in therapeutic procedures.

Localization of parathyroid tumors using endoscopic ultrasonography in primary hyperparathyroidism

Parathyroid adenomas responsible for primary hyperparathyroidism may be difficult to detect preoperatively. Furthermore parathyroid adenomas may arise behind the (nodular) thyroid gland, in a deep cervical location, and plans should be plane. The purpose of the present prospective study was to evaluate echoendoscopy, and to compare its accuracy to that of non invasive tests. Fourteen consecutive patients with primary hyperparathyroidism were prospectively studied. All patients underwent echoendoscopy, ultrasonography (US), CT scanning or magnetic resonance imaging (MRI) and Tc 99m sestamibi scanning before undergoing initial neck exploration. The parathyroid pathology was a solitary adenoma in 13 patients and a 4 glands hyperplasia in one. All tests were corroborating in 5 cases. Four adenomas were localized to the correc tside (33%), and no test accurately localized all hyperplastic glands. EUS, sestamibi and CT scanning or MRI correctly identified 10 parathyroid tumors in 14 cases (71%). US correctly localized only 5 adenomas (sensitivity 36%). The sensitivity of EUS to detect parathyroid adenomas is superior to US (p<0.05) and comparable to that of other non invasive tests. We conclude that EUS may be an useful tool to localize parathyroid lesions. This method may replace US prior to initial neck exploration with further miniaturization of probes, or find an intermediate place among invasive and noninvasive preoperative localization procedures in patients with persistent or recurrent PHPT.

Endosonographic diagnosis of submucosal upper gastrointestinal tract lesions and large fold gastropathies by catheter ultrasound probe

BACKGROUND

The unique ability of EUS to depict wall layers makes it possible to accurately evaluate submucosal lesions of the digestive tract and large-fold gastropathies. Although EUS requires a second endoscopic examination, miniature US probes introduced through the accessory channel of a conventional endoscope permit US examination during routine endoscopy.

METHODS

By means of catheter probe sonography and conventional EUS, we evaluated 33 patients with a radiographic or endoscopic finding of a submucosal lesion of the upper GI tract or with large-fold gastropathies and histologically negative biopsies obtained at a previous endoscopy. A miniature multifrequency probe was used for catheter probe sonography.

RESULTS

For 25 submucosal lesions catheter probe sonography results were superimposable on those obtained with EUS. In evaluating submucosal lesions, catheter probe sonography yielded the same results as conventional EUS in terms of depiction, measurement, and identification of the originating layer of the tumor. In the study of 8 large-fold gastropathies, catheter probe sonography missed the presence of ascites and enlarged lymph nodes in a case of gastric linitis, but produced the same results as conventional EUS in the other cases.

CONCLUSIONS

For the evaluation of benign submucosal lesions and large-fold gastropathies, catheter probe sonography appears to be sufficient and could thus replace conventional EUS for these indications.