Background/Aims: Shear wave elastography (SWE) is used for liver fibrosis staging based on stiffness measurements. It can be performed using endoscopic ultrasound (EUS) or a transabdominal approach. Transabdominal accuracy can be limited in patients with obesity because of the thick abdomen. Theoretically, EUS-SWE overcomes this limitation by internally assessing the liver. We aimed to define the optimal technique for EUS-SWE for future research and clinical use and compare its accuracy with that of transabdominal SWE. Methods: Benchtop study: A standardized phantom model was used. The compared variables included the region of interest (ROI) size, depth, and orientation and transducer pressure.Porcine study: Phantom models with varying stiffness values were surgically implanted between the hepatic lobes. Results: For EUS-SWE, a larger ROI size of 1.5 cm and a smaller ROI depth of 1 cm demonstrated a significantly higher accuracy. For transabdominal SWE, the ROI size was nonadjustable, and the optimal ROI depth ranged from 2 to 4 cm. The transducer pressure and ROI orientation did not significantly affect the accuracy. There were no significant differences in the accuracy between transabdominal SWE and EUS-SWE in the animal model. The variability among the operators was more pronounced for the higher stiffness values. Small lesion measurements were accurate only when the ROI was entirely situated within the lesion. Conclusions We defined the optimal viewing windows for EUS-SWE and transabdominal SWE. The accuracy was comparable in the non-obese porcine model. EUS-SWE may have a higher utility for evaluating small lesions than transabdominal SWE.

Background/Aims: Upper gastrointestinal bleeding (UGIB) is a life-threatening condition that necessitates early identification and intervention and is associated with substantial morbidity, mortality, and socioeconomic burden. However, several diagnostic challenges remain regarding risk stratification and the optimal timing of endoscopy. The PillSense System is a noninvasive device developed to detect blood in patients with UGIB in real time. This study aimed to assess the safety and performance characteristics of PillSense using a simulated bleeding model. Methods: A preclinical study was performed using an in vivo porcine model (14 animals). Fourteen PillSense capsules were endoscopically placed in the stomach and blood was injected into the stomach to simulate bleeding. The safety and sensitivity of blood detection and pill excretion were also investigated. Results: All the sensors successfully detected the presence or absence of blood. The minimum threshold was 9% blood concentration, with additional detection of increasing concentrations of up to 22.5% blood. All the sensors passed naturally through the gastrointestinal tract. Conclusions This study demonstrated the ability of the PillSense System sensor to detect UGIB across a wide range of blood concentrations. This ingestible device detects UGIB in real time and has the potential to be an effective tool to supplement the current standard of care. These favorable results will be further investigated in future clinical studies.

Background/Aims: Upper gastrointestinal bleeding (UGIB) is the most common GI condition requiring hospitalization, and can be diagnosed by direct visualization. The present study aimed to evaluate the safety and feasibility of using the PillSense system (EnteraSense Ltd.), a novel diagnostic tool designed for the rapid in vivo detection of UGIB, in human volunteers. Methods: In the present study, 10 volunteers swallowed a PillSense capsule, followed by 2 servings of an autologous blood preparation. Participants were monitored for capsule passage, overall tolerability of the procedure, and adverse events. Results: The procedure was completed per the protocol established in the present study in 9/10 cases. In 9 of the subjects, after capsule ingestion, the device indicated the absence of blood with sensor output values of 1. After the ingestion of the first blood mixture, the sensor outputs of all devices increased from 2.8 to 4, indicating that each camera detected blood. The sensor output remained within that range after the ingestion of the second mixture; however, in one case, the baseline capsule signal was positive, because of a preexisting condition. The passage of the capsule was verified in all patients, and no adverse events were reported. Conclusions The first trial of the PillSense system in human subjects demonstrated the feasibility, safety, and tolerability of utilizing this product as a novel, noninvasive, and easy-to-use triage tool for the diagnosis of patients suspected of having UGIB.

No abstract available.
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BACKGROUND/AIMS: Liver biopsy has traditionally been used for determining the degree of fibrosis, however there are several limitations. Endoscopic ultrasound (EUS) real-time elastography (RTE) is a novel technology that uses image enhancement to display differences in tissue compressibility. We sought to assess whether liver fibrosis index (LFI) can distinguish normal, fatty, and cirrhotic liver tissue. METHODS: A total of 50 patients undergoing EUS were prospectively enrolled. RTE of the liver was performed to synthesize the LFI in each patient. Univariate and multivariable analyses were performed. Chi-square and t-tests were performed for categorical and continuous variables, respectively. A p-value of <0.05 was considered significant. RESULTS: Abdominal imaging prior to endoscopic evaluation suggested normal tissue, fatty liver, and cirrhosis in 26, 16, and 8 patients, respectively. Patients with cirrhosis had significantly increased mean LFI compared to the fatty liver (3.2 vs. 1.7, p<0.001) and normal (3.2 vs. 0.8, p<0.001) groups. The fatty liver group showed significantly increased LFI compared to the normal group (3.8 vs. 1.4, p<0.001). Multivariable regression analysis suggested that LFI was an independent predictor of group features (p<0.001). CONCLUSIONS: LFI computed from RTE images significantly correlates with abdominal imaging and can distinguish normal, fatty, and cirrhotic-appearing livers; therefore, LFI may play an important role in patients with chronic liver disease.
Adipose Tissue ; Biopsy* ; Elasticity Imaging Techniques* ; Endosonography ; Fatty Liver ; Fibrosis ; Humans ; Image Enhancement ; Liver Cirrhosis ; Liver Diseases* ; Liver* ; Prospective Studies* ; Ultrasonography*

Background/Aims: Endoscopic retrograde cholangiopancreatography (ERCP) requires a unique skill set. Currently, there is no objective methodology to assess and train a professional to perform ERCP. This study aimed to develop and validate a novel ERCP simulator. Methods: The simulator consists of papillae presenting different anatomy and positioned in varied locations. Deep cannulation of the pancreatic duct, followed by the bile duct, was performed. The time allotted was 5 minutes. The content validity indexes (CVIs) for realism, relevance, and representativeness were calculated. Correlation between ERCP experience and simulator score was determined. Results: Twenty-three participants completed the simulation. The CVIs for realism were orientation of duodenoscope to papilla (1.00), angulation of papillotome to achieve cannulation (0.71), and haptic feedback during cannulation (0.80). The CVIs for relevance were use of elevator (1.00), wheels to achieve en face orientation (1.00), and papillotome for selective cannulation (1.00). Regarding CVI for representativeness, the results were as follows: basic cannulation (0.83), papilla locations (0.83), and papilla anatomies (0.80). The novice, intermediate, and experienced groups scored 6.7±8.7, 30.0±16.3, and 74.4±43.9, respectively (p<0.0001). There was a strong correlation between the ERCP experience level and the individual’s simulator score (Pearson value of 0.77, R2 of 0.60). Conclusions This simulator appears to be realistic, relevant, and representative of ERCP cannulation techniques. Additionally, it is effective at objectively assessing basic ERCP skills by differentiating scores based on clinical experience.

Background/Aims: Percutaneous liver biopsy (PCLB) or transjugular liver biopsy (TJLB) have traditionally been performed to obtain a sample of hepatic tissue; however, endoscopic ultrasound-guided liver biopsy (EUSLB) has become an attractive alternative. The aim of this study was to compare the efficacy and safety of EUSLB, PCLB, and TJLB. Methods: Search strategies were developed in accordance with PRISMA and MOOSE guidelines. Major outcomes included the following: adequacy of biopsy specimens (i.e., complete portal triads [CPT], total specimen length [TSL] in mm, and length of longest piece [LLP]) in mm), and rate of adverse events. Only studies comparing all biopsy approaches (i.e., EUSLB, PCLB, and TJLB) were included. Results: Five studies (EUSLB [n=301]; PCLB [n=176]; and TJLB [n=179]) were included. Biopsy cumulative adequacy rates for EUSLB, PCLB, and TJLB were 93.51%, 98.27%, and 97.61%, respectively. Based on the subgroup analysis limited to EUS biopsy needles in current clinical practice, there was no difference in biopsy adequacy or adverse events for EUSLB compared to PCLB and TJLB (all p>0.050). A comparison of EUSLB and PCLB revealed no difference between specimens regarding both CPT (p=0.079) and LLP (p=0.085); however, a longer TSL (p<0.001) was observed. Compared to TJLB, EUSLB showed no difference in LLP (p=0.351), fewer CPT (p=0.042), and longer TSL (p=0.005). Conclusions EUSLB appears to be a safe, minimally invasive procedure that is comparable to PCLB and TJLB regarding biopsy specimens obtained and rate of adverse events associated with each method.

Background/Aims: The diagnosis of biliary strictures can be challenging. There are no systematic reviews studying same-session endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis of biliary strictures. Methods: A systematic review was conducted on studies analyzing same-session EUS and ERCP for tissue diagnosis of suspected malignant biliary strictures. The primary outcome was the accuracy of each method individually compared to the two methods combined. The secondary outcome was the accuracy of each method in pancreatic and biliary etiologies. In the meta-analysis, we used Forest plots, summary receiver operating characteristic curves, and estimates of the area under the curve for intention-to-treat analysis. Results: Of the 12,132 articles identified, six were included, resulting in a total of 497 patients analyzed. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and accuracy of the association between the two methods were: 86%, 98%, 12.50, 0.17, and 96.5%, respectively. For the individual analysis, the sensitivity, specificity and accuracy of EUS-FNA were 76%, 100%, and 94.5%, respectively; for ERCP-based tissue sampling, the sensitivity, specificity, and accuracy were 58%, 98%, and 78.1%, respectively. For pancreatic lesions, EUS-FNA was superior to ERCP-based tissue sampling. However, for biliary lesions, both methods had similar sensitivities. Conclusions Same-session EUS-FNA and ERCP-based tissue sampling is superior to either method alone in the diagnosis of suspected malignant biliary strictures. Considering these results, combination sampling should be performed when possible.

Background/Aims: Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is preferred for sampling of lymph nodes (LNs) adjacent to the gastrointestinal wall; however, fine-needle biopsy (FNB) may provide improved diagnostic outcomes. This study aimed to evaluate the comparative efficacy and safety of FNA versus FNB for LN sampling. Methods: This was a multicenter retrospective study of prospectively collected data to evaluate outcomes of EUS-FNA and EUS-FNB for LN sampling. Characteristics analyzed included sensitivity, specificity, accuracy, the number of needle passes, diagnostic adequacy of rapid on-site evaluation (ROSE), cell-block analysis, and adverse events. Results: A total of 209 patients underwent EUS-guided LN sampling. The mean lesion size was 16.22±8.03 mm, with similar sensitivity and accuracy between FNA and FNB ([67.21% vs. 75.00%, respectively, p=0.216] and [78.80% vs. 83.17%, respectively, p=0.423]). The specificity of FNB was better than that of FNA (100.00% vs. 93.62%, p=0.01). The number of passes required for diagnosis was not different. Abdominal and peri-hepatic LN location demonstrated FNB to have a higher sensitivity (81.08% vs. 64.71%, p=0.031 and 80.95% vs. 58.33%, p=0.023) and accuracy (88.14% vs. 75.29%, p=0.053 and 88.89% vs. 70.49%, p=0.038), respectively. ROSE was a significant predictor for accuracy (odds ratio, 5.16; 95% confidence interval, 1.15–23.08; p=0.032). No adverse events were reported in either cohort. Conclusions Both EUS-FNA and EUS-FNB are safe for the diagnosis of LNs. EUS-FNB is preferred for abdominal LN sampling. EUSFNA+ ROSE was similar to EUS-FNB alone, showing better diagnosis for EUS-FNB than traditional FNA. While ROSE remained a significant predictor for accuracy, due to its poor availability in most centers, its use may be limited to cases with previous inconclusive diagnoses.