Capability of Radial- and Convex-Arrayed Echoendoscopes for Visualization of the Pancreatobiliary Junction

The Role of Endoscopic Ultrasound in Ampullary Lesion Management

Ampullary lesions, neoplasms originating in the papilla of Vater, represent a rare yet clinically significant group of tumors with diverse etiologies and management challenges. This comprehensive review aims to elucidate the pivotal role of endoscopic ultrasound (EUS) in the diagnosis, staging, and management of ampullary lesions. This review begins by providing an overview of ampullary lesions, their epidemiology, and associated risk factors. We delve into their clinical presentation, emphasizing the importance of early and accurate diagnosis. Furthermore, we explore the limitations of traditional diagnostic modalities and highlight the growing relevance of EUS in ampullary lesion evaluation. We discuss the superior spatial resolution of EUS in comparison with other imaging methods, and we present an in-depth analysis of EUS-guided sampling and its pivotal role in obtaining histological samples for accurate diagnosis. In addition to diagnosis, we examine the indispensable role of EUS in ampullary lesion staging and its clinical implications. Furthermore, we discuss the potential of EUS in the surveillance and follow-up of ampullary lesions, ensuring timely detection of recurrence and monitoring treatment response in sporadic cases and in the context of familial syndromes, such as familial adenomatous polyposis (FAP). In conclusion, this review underscores the indispensable role of endoscopic ultrasound in the multifaceted approach to ampullary lesion evaluation. EUS not only enhances diagnostic accuracy but also informs treatment decisions and minimally invasive therapeutic interventions. As our understanding of ampullary lesions continues to evolve, EUS remains an invaluable tool for the improvement of patient outcomes and quality of life.

New gel immersion endoscopic ultrasonography technique for accurate periampullary evaluation

BACKGROUND

Visualization of the pancreatobiliary junction is one of the challenges faced by endoscopic ultrasonography (EUS). The water-filling technique, which allows for the observation of the ampulla at a suitable distance by injecting water into the lumen of the duodenum, was used for this purpose. However, a new gel immersion technique has recently been introduced for visualizing the gastrointestinal tract. This study investigated the effectiveness of visualizing the pancreatobiliary junction in EUS by comparing both water filling and the new gel immersion technique in identical cases.

METHODS

The study ran from June to December 2021. Ten images from each technique were retrospectively compared by three independent researchers. The primary result of the study was the number of images depicting the "Pancreatic and Biliary Ducts Penetrating the Duodenal Muscularis Propria" (defined as Excellent observation) in each technique. The secondary outcome was defined as gel immersion technique's safety and impact on duodenal lumen distension.

RESULTS

Ten patients used the gel immersion technique. All patients underwent the water-filling technique first, followed by gel injection after the water was completely aspirated. The average number of pictures rated as "Excellent observation," which is the primary outcome, was significantly higher with the gel immersion technique than with water filling, and no adverse events were observed. The subanalysis revealed that both convex and radial echoendoscopes are equally effective at depicting the ampulla with the gel immersion technique.

CONCLUSIONS

The ability to depict the pancreatobiliary junction using the gel immersion technique is superior to that of the water-filling method, which may allow for a more detailed assessment of the ampullary region with both radial and convex echoendoscopes. This can be a useful EUS technique for diagnosing pancreaticobiliary maljunction or periampullary tumors.

Pancreatic duct imaging during aging

As part of the aging process, fibrotic changes, fatty infiltration, and parenchymal atrophy develop in the pancreas. The pancreatic duct also becomes wider with age. This article provides an overview of the diameter of the pancreatic duct in different age groups and different examination methods. Knowledge of these data is useful to avoid misinterpretations regarding the differential diagnosis of chronic pancreatitis, obstructive tumors, and intraductal papillary mucinous neoplasia (IPMN).

Evaluation of a novel radial echoendosonoscope with a piezoelectric-composite transducer: An open-label, multicenter, randomized, parallel-group, noninferiority clinical trial

BACKGROUND AND OBJECTIVES

EUS is widely used in the clinical practice. This study aimed to evaluate the efficacy of a novel echoendoscope regarding image quality, maneuverability, stability of the entire machine system, and safety.

SETTING AND DESIGN

We conducted this open-label, multicenter, randomized, parallel-group, noninferiority clinical trial in three tertiary hospitals between November 2018 and April 2019.

SUBJECTS AND METHODS

One hundred and thirty patients were included. The stratified segment randomization method was employed. Sixty-five patients in the test group received an EUS examination using the new material radial echoendoscope, and 65 patients in the control group received an EUS examination using the existing endoscope. We recorded the image quality, maneuverability, stability of the entire machine system, and safety. For the main outcome, comprehensive image quality, the groups were compared with the noninferiority test, using the confidence interval method and 10% as the noninferiority threshold. The Pearson Chi-square test was used to compare the incidence of adverse events between the groups.

RESULTS

Sixty-five patients in the test group and 63 patients in the control group were analyzed. Two patients in control group did not complete an EUS examination due to machine problems. There were no significant differences in image quality, maneuverability of the echoendoscope, stability of the entire machine system, and safety between the groups.

CONCLUSIONS

This new material radial echoendoscope showed good capabilities for image quality, maneuverability, stability of the entire machine system, and safety. Our data suggest that the new echoendoscope may provide an additional option for endoscopic physicians.

Linear-array EUS improves the accuracy of predicting deep submucosal invasion in non-pedunculated rectal polyps compared with radial EUS: a prospective observational study

BACKGROUND

Radial endoscopic ultrasound (EUS) is typically used to estimate the depth of rectal polyp invasion, however, there are no data on linear EUS in this setting and its relative accuracy compared to radial EUS.

METHODS

In this prospective cohort study, 89 patients with non-pedunculated rectal polyp who underwent linear EUS or radial EUS were prospectively enrolled. The invasion depth was measured for each polyp and categorized as mucosal to shallow submucosal(SM_s) or deep submucosal(SM_d) invasion. Invasion measurements were compared with the final diagnosis on histopathology.

RESULTS

A total of 58 patients underwent radial EUS and 31 patients underwent linear EUS examination. There were 38 lesions correctly diagnosed in the radial EUS group and 29 correctly diagnosed lesions in the linear EUS group. The diagnostic accuracy of SM_d invasion for linear EUS was significantly higher than radial EUS (0.936 vs. 0.655, p = 0.003). A significant difference was also noted for specificity between the two groups (0.963 vs. 0.659, p = 0.003). Univariate analysis showed radial EUS type (OR 0.131, 95% CI 0.028-0.606, p = 0.009) to be an independent predictor for incorrect diagnosis. The area under the receiver operating curve (ROC) was 0.856 and 0.651 for linear EUS and radial EUS, respectively. It was noted that four patients underwent unnecessary surgery for radial EUS while there were no such patients in the linear EUS group.

CONCLUSIONS

Linear EUS was more accurate for determining SM_d invasion and contributed to the selection of appropriate treatment modalities in patients with non-pedunculated rectal polyp.