Diagnostic EUS Research Articles

Top Tips for Diagnostic Rectal EUS and Assessment of Rectal Sphincters

Top Tips for Diagnostic Rectal EUS and Assessment of Rectal Sphincters

Performance and safety of diagnostic EUS FNA/FNB and therapeutic ERCP in patients with borderline resectable and locally advanced pancreatic cancer - results from a population-based, prospective cohort study

Objective: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS FNA/FNB) and potential endoscopic retrograde cholangiopancreatography (ERCP) for biliary decompression are indicated in patients with pancreatic cancer before initation of primary chemotherapy. This study aims to investigate the performance and safety of these two procedures in patients with borderline resectable (BRPC) or locally advanced pancreatic cancer (LAPC). Methods: Endoscopy and pathology reports, and hospital records of consecutive patients with a radiological diagnosis of BRPC/LAPC included in a population based, protocol-driven study (NORPACT-2) were reviewed. Results: Of 251 patients, 223 (88.9%) underwent EUS-FNA/FNB, and 133 (53%) underwent ERCP. Repeated EUS attempts were performed in 33 (14.8%), eight (3.6%), and four (1.8%) patients. FNA was performed in 155 procedures, FNB in 30, and combined EUS-FNA/FNB in 83. Diagnostic accuracy was 86.1% for first EUS-FNA/FNB. The cumulative diagnostic accuracy for all attempts was 96%. False positive rate for malignancy was 0.9%. Of a total of 149 ERCP procedures, 122 (81.9%) were successful, and 27 (18.1%) were unsuccessful. Success rate of first ERCP attempt was 80.5% (107/133). Sixteen patients (12%) underwent a second attempt with a success rate of 93.8% (15 of 16). Combined EUS and ERCP was performed in 41 patients. Complications occurred in eight procedures (3%) after EUS-FNA/FNB, 23 procedures (15.3%) after ERCP, and four (9.8%) patients after combined EUS-FNA/FNB and ERCP. Conclusion: EUS-FNA/FNB and ERCP with biliary stenting in patients with BRPC/LAPC demonstrated acceptable performance and safety. Repeat procedures were performed with high success rates. Same session EUS-FNA/FNB and ERCP for biliary decompression is safe.

Comparing the efficacy of EUS versus MRCP with ERCP as gold standard in patients presenting with partial biliary obstruction - finding a better diagnostic tool.

To evaluate the diagnostic accuracy of different imaging modalities in patients with partial biliary obstruction with no obvious aetiology on initial imaging. This is a prospective single-centre cohort study carried out at Pak Emirates Military Hospital, Rawalpindi from June 2019 to June 2021 with non-probability consecutive sampling. Patients with ages 16 to 75 years, presenting with partial biliary obstruction and undetermined aetiology on initial imaging (TUS and MRCP) were enrolled. EUS was performed for each of these patients and the case was regarded as "true positive" or "true negative" if the findings of imaging modality correlated to those of ERCP. ROC curve, sensitivity, specificity, PPV, NPV and AUC (with 95% confidence interval) were drawn for all the diagnostic tools using SPSS V. 21. A total of 65 patients were enrolled over a period of two years with male to female ratio of 1.4:1. Forty-four patients had an intermediate risk of choledocholithiasis upon preliminary evaluation whereas, 48(74%) of the participants had CBD calculi or sludge confirmed upon subsequent ERCP. Trans-abdominal ultrasound showed the lowest sensitivity (29.2%), specificity (85%), NPV 12% and PPV 93% for diagnosing CBD calculi. This was followed by MRCP with a sensitivity of 37.5%, specificity of 100%, NPV of 36.2% and PPV of 100%. EUS showed the maximum diagnostic accuracy with AUC of 1.0 and a 100% sensitivity and specificity when compared with ERCP as gold standard. EUS is superior to MRCP in terms of diagnostic accuracy as minimally invasive diagnostic tool and EUS superiority is particularly relevant in patients with intermediate risk of choledocholithiasis.

S1076 Anesthesia Care Provider Sedation (ACPS) Is Superior to Conscious Sedation (CS) for Successful Diagnostic Tissue Acquisition in Endoscopic Ultrasound Fine Needle Aspiration and/or Biopsy (EUS FNA/B)

Introduction: EUS-FNA/B is frequently used for diagnosis of suspicious intestinal, subepithelial, and extraintestinal lesions. Our study aimed to evaluate the role of sedation in the diagnostic yield of EUS-FNA/B of suspicious lesions in the mediastinum, abdomen and pelvis. Given frequent use and experience of CS with diagnostic EUS at our institution, we hypothesized that the diagnostic yield of EUS-FNA/B would be equivalent for both sedation groups. Methods: A retrospective, single-center, cohort study was conducted including patients aged >18 years old who received EUS-FNA/B at our institution from 9/2018 – 5/2021 for further evaluation of suspicious lesions. Relevant baseline variables were collected for both groups. The primary endpoint was EUS diagnostic yield of neoplastic lesions. Successful cytologic diagnosis was defined by positive or suspicious results. Unsuccessful cytological results were defined by unsatisfactory, indeterminate, or false negative results. Secondary endpoint was adverse events (AEs). AEs were recorded for EUS only (EUS/ERCP patients were excluded from AE tally due to possible confounding). Baseline statistical comparison was done using the Chi-square test and Wilcoxon two sample tests. Univariate and multivariate logistic regression analysis was conducted to further evaluate primary and secondary outcomes. All statistical analyses were performed utilizing SAS Software (version 9.4; SAS Institute Inc. Cary, NC, USA). Results: 369 patients met initial inclusion criteria. 67 cases with confirmed or suspected benign lesions were eliminated from analysis. Successful FNA/B was present in 146/196 (74.5%) of patients in the ACPS group and 66/106 (62.3%) in the CS group, (p = 0.0274). Upon multivariate logistic regression controlling for lesion size, location, needle size, number of passes, and presence of ROSE, the difference in diagnostic yield between the CS and GA groups remained statistically significant (adjusted odds ratio [95% CI]: 0.558 [0.315 - 0.987], P = 0.0451) (Table). Adverse events (AEs) occurred more frequently in the ACPS group. This difference was sustained on multivariate analysis controlling for BMI, age, and ASA class. Conclusion: ACPS is associated with improved diagnostic yield when performing EUS-FNA/B for suspicious lesions in the mediastinum, abdomen, and pelvis. AEs occur more frequently in ACPS albeit most AEs are mild and associated with general anesthesia. Table 1. - Descriptive Analysis of demographics, Univariate/Multivariate logistic regression analysis, and Adverse Events Demographics Type of sedation P value Anesthesia Conscious Sedation N(number of patients) % N % Gender 0.07 Male 110 47.21 51 37.5 Female 123 52.79 85 62.5 ASA Class < 0.001 1 5 2.15 8 5.88 2 45 19.31 63 46.32 3 169 72.53 65 47.79 4 14 6.01 . . Location 0.001 Thoracic 1 0.43 1 0.74 Abdominal (non-pancreas) 26 11.16 22 16.18 Pelvic 3 1.29 2 1.47 pancreas ampulla/uncinate/head 130 55.79 42 30.88 neck/body/tail pancreas 50 21.46 46 33.82 SEL 22 9.44 22 16.18 Cytologic Result 0.007 Unsatisfactory specimen 14 6.01 22 16.18 Negative for malignancy 43 18.45 33 24.26 Atypical/Indeterminate 30 12.88 15 11.03 Suspicious for malignancy 10 4.29 3 2.21 Positive for malignancy 136 58.37 63 46.32 FNB < 0.001 N 140 60.09 115 84.56 Y 93 39.91 21 15.44 Univariate and Multivariate logistic regression analysis Univariate logistic regression (Crude effect) Unit OR 95% Confidence Limits p-Value Type of sedation (CS vs Anesthesia) 1 0.565 0.34 0.938 0.0274 Adjusted Effect Unit OR 95% Confidence Limits Column1 p-Value Type of sedation CS vs Anesthesia 1 0.558 0.315 0.987 0.0451 Location Others vs (pancreas ampulla/uncinate/head) 1 0.46 0.2 1.063 0.0691 Number of needle passed 1 1.473 1.191 1.822 0.0004 Categories of Adverse Events Type of Sedation CS Anesthesia Severity GA MAC Mild 3 14 2 Moderate 1 5 0 Severe 0 3 0 Fatal 0 0 0 Total 4 22 2 **Total of 28 adverse events.

S1154 Training Experience and Outcomes of the First Cohort of the ASGE Diagnostic EUS Training Program

Introduction: Despite the expanding role and need for endoscopic ultrasound, training opportunities for established endoscopists in the USA are limited. ASGE launched a novel competency-based program to address this training need in 2019. It includes an online learning modules, live webinars, a hands-on weekend course, a summative knowledge exam, followed by a customizable preceptorship with an EUS expert. Aim: To describe the training experience of a sample from the first cohort of the ASGE Diagnostic EUS training program. Methods: A total of 26 applicants were chosen for the first cohort of the training program in 2019. We describe the experience of 3 endoscopists (ST at the Swedish Digestive Health Institute, Seattle, WA; BM at the Borland Groover Clinic, Jacksonville, FL and JH at Guthrie, Sayre, PA) who completed their hands-on training. Their case volumes were 160 (4 mentors), 185 (2 mentors) and 185 (3 mentors) respectively over a total of 12 weeks each. While 1 trainee (JH) was able to get trained at the same institute where he was employed, the other 2 (ST, JH) had to seek training in another state due to lack of preceptorship sites within their states of employment. One center tracked TEESAT scores (The EUS and ERCP Skills Assessment Tool) for every 5 procedures for their trainee (ST), and he was noted achieved a global score of 4 by the 150 th procedure. Results: All 3 trainees have been credentialed for EUS privileges at their respective institutes, and are performing EUS independently. Conclusion: The ASGE EUS diagnostic training program was able to fulfil the training needs of motivated established clinicians in full time practice. The main challenges encountered were identifying willing institutes and expert EUS preceptors, and institutional administrative barriers. COVID restrictions were a unique hurdle to the timely completion of preceptorship. This program’s success in the future depends on buy in from EUS experts in the community and their respective institutions.

S3037 Hepatocellular Carcinoma With Para-Celiac Lymph Node Metastasis Presenting as Unknown Primary Neoplasm in the Post-Liver Transplant Setting

Introduction: Metastatic HCC without primary liver lesion is an exceedingly rare clinicopathologic entity. Only a handful of case reports have been reported to date, mostly involving bony structures without primary liver cancer. To our knowledge, we hereby present the first case of metastatic HCC involving the para-celiac lymph nodes in the post-liver transplant setting. Case Description/Methods: A 73-year-old male who previously underwent liver transplant for non-alcoholic steatohepatitis was admitted to GI for the evaluation of a suspicious pancreatic tail cyst. He denied acute GI symptoms. Laboratory studies revealed normal liver enzymes. CT abdomen and pelvis showed a 2-cm lesion located under the right hemidiaphragm, posterior to the right hepatic lobe. Subsequently, the patient underwent diagnostic EUS with biopsy for both lesions. EUS revealed an irregularly shaped oval cyst in the tail, round cysts in the body and neck, and a complex of small cysts in the pancreatic head. The 45 x 55-mm para-celiac mass was irregularly shaped, hypoechoic, homogenous solid lesion, located lateral to the celiac axis. It had well-defined endosonographic borders. Immunostaining of the fine-needle biopsy (FNB) of the para-celiac mass was positive for Hep Par-1 and pancytokeratin, consistent with metastatic HCC (Figure 1; A&B). Fine-needle aspiration (FNA) of the pancreatic cysts was negative for malignancy. Alpha-fetoprotein level was 11.1 ng/mL. The diagnosis of HCC of unknown primary was finally made. The patient then underwent an uneventful surgical resection. Discussion: To our research, this is the first reported case of metastatic HCC without primary liver lesion involving the para-celiac lymph nodes in a post-transplant patient. With regard to pathogenesis, one theory implicates the presence of ectopic liver tissue that transforms into HCC. The presence of micro-HCC that regresses spontaneously or gets destroyed by the immune system can also be a plausible explanation. Standard diagnostic protocol for HCC consists of imaging (CT or MRI) and/or biopsy. Even in patients with cirrhosis, the diagnostic modality of choice is imaging and liver biopsy is less frequently performed. Biopsy is recommended for atypical hepatic lesions on imaging or nonclassical enhancement patterns or detection in the absence of cirrhosis. No standardized treatment exists for metastatic HCC with unknown primary. This report illustrates that clinicians should consider HCC while evaluating patients for the primary origin of metastatic carcinoma.Figure 1.: Immunostaining of the para-celiac mass. Endoscopic ultrasound-guided fine-needle biopsy (FNB) specimen indicating positive status for Hep Par-1 and pancytokeratin.

S2835 Gastro-Cholecysto-Colonic Fistula Following Endoscopic Ultrasound-Guided Gallbladder Drainage for Stump Cholecystitis: A Case Report

Introduction: Cholecystocolonic fistulas (CCF) usually occur as a complication of gallstones but cases due to malignancy, peptic ulcers, and Crohn’s disease have been reported. We present a case of a gastro-cholecysto-colonic fistula after endoscopic ultrasound guided-gallbladder drainage (EUS-GBD) for stump cholecystitis. Case Description/Methods: A 50 year old male presented with abdominal pain. CT scan noted acute cholecystitis. He underwent laparoscopic converted to open subtotal cholecystectomy due to significant inflammation around the gallbladder. He represented 3 weeks later for abdominal pain. CT showed stump cholecystitis. Gastroenterology was consulted for EUS-GBD given his poor surgical candidacy. Diagnostic EUS revealed choledocholithiasis. Endoscopic retrograde cholangiography (ERC) with cholangioscopy, electrohydraulic lithotripsy, and stone removal was completed. Transgastric EUS-GBD with a 10 x 10 mm electrocautery enhanced lumen apposing metal stent (LAMS) was then performed followed by double pigtail stent (DPT) placement within the LAMS. At a follow up visit, abdominal pain resolved but he developed debilitating diarrhea and was started on cholestyramine. Upper endoscopy 4 weeks after EUS-GBD revealed a gastro-cholecysto-colonic fistula with the proximal end of the DPT in the colon. Cholecystoscopy confirmed absence of gallstones so the LAMS and DPT were removed. Clips were used to close the cholecystogastric tract. Oral contrasted CT with delayed images showed tethering of the gallbladder to the hepatic flexure but no extravasation of contrast into the gallbladder from either the stomach or colon. Given this, clinical observation was pursued. Six weeks later, CT noted similar tethering without contrast leak. On colonoscopy, an area of inflamed mucosa at the hepatic flexure was seen without a patent fistula tract. Biopsies showed chronic colitis. Diarrhea subsequently resolved. (Figure) Discussion: CCFs are a rare complication of gallstone disease. If untreated, biliary sepsis can occur. Surgery is the standard treatment but endoscopic transpapillary gallbladder drainage with a DPT can promote fistula healing in non-surgical patients. We present a case of a gastro-cholecysto-colonic fistula in a poor surgical candidate after EUS-GBD for stump cholecystitis. This was managed with closure of the cholecystogastric tract. CCF closure occurred spontaneously. In cases of persistent CCF, transpapillary gallbladder drainage should be considered.Figure 1.: A. Double pigtail stent migrated into transverse colon with gastro-cholecysto-colonic fistula as viewed from the gallbladder lumen. B. CT scan showing tethering of hepatic flexure to remnant gallbladder (red arrow) without contrast extravasation into the gallbladder from the stomach or colon. C. Closed cholecystocolonic fistula (black arrow) viewed from the hepatic flexure.

Gut microbiota composition and outcomes following neoadjuvant therapy in patients with localized pancreatic cancer: A prospective biomarker study.

4143 Background: The prognostic role of the gut microbiome, which modulates cancer development and therapeutic response, is unknown in patients with pancreatic ductal adenocarcinoma (PDAC). With increasing utilization of neoadjuvant therapy (NAT) prior to pancreatic cancer surgery, identification of patient-specific biologic signatures associated with NAT response a priori could help inform PDAC precision medicine. Thus, we assessed the influence of the baseline gut microbiome on clinical outcomes in patients with PDAC receiving NAT. Methods: Stool samples were collected at diagnosis from 42 consenting patients with localized PDAC intending to undergo NAT and surgical resection between 2018 and 2020. 16S rRNA sequencing was completed on pre-NAT stool and resected tumor samples. Microbiota alpha diversity and log transformed taxonomic classifications were utilized in multiple regression analyses to predict oncologic outcomes. Results: Five patients progressed during NAT and eight of the 37 operated patients were deemed NAT responders, demonstrating pathologic near complete or partial response (CAP 0-2), T1N0 AJCC 8th staging, and ≥ 80% CA 19-9 reduction. Compared to the gut, the tumor microbiota demonstrated remarkably reduced Shannon diversity (2.4±0.5 vs 1.5±0.4, p&lt; 0.0001) and distinct taxa (75.2±19.7 vs 8.0±4.5, p&lt; 0.0001) and, accordingly, was not associated with clinical outcomes. Overall, several taxa, including Bacteroides and Akkermansia, were enriched in the gut relative to the tumor ( p&lt; 0.001). The gut microbiota of NAT non-responders had an increased proportion of the gemcitabine metabolizing Enterobacteriaceae (additive log ratio (ALR) -3.4±2.0 vs -8.7±0.8, p= 0.0004). NAT responders, by contrast, had an increased proportion of the adaptive immune cell activating Akkermansia (ALR -0.9±1.2 vs -6.2±3.3, p= 0.0004). The incidence of jaundice or biliary stent placement was associated with relative increases in Enterobacteriaceae (+3.3 ALR, p&lt; 0.01 and +4.9 ALR, p&lt; 0.0001) and decreases in Akkermansia (-3.2 ALR, p= 0.02 and -2.4 ALR, p= 0.057), without altering total gut microbiota diversity. Age, sex, BMI, comorbidities, receipt of pre-NAT antibiotics, diagnostic EUS tumor size, resectability, and pre-NAT CA 19-9 were not predictive of NAT response or survival in a univariate regression model. However, inclusion of gut microbiota data improved the ability of the model to predict NAT response ( p= 0.016, adjusted R2 0.76) and survival ( p= 0.001, adjusted R2 0.89), with Enterobacteriaceae (FDR p= 0.012) and Akkermansia (FDR p= 0.015) being significant negative and positive predictors of NAT response, respectively. Conclusions: The baseline gut microbiota could be leveraged as a biomarker of NAT response and prognosis in patients with pancreatic cancer and warrants further investigation.

EUS-directed transgastric interventions in Roux-en-Y gastric bypass anatomy: a multicenter experience

Placement of a lumen-apposing metal stent (LAMS) between the gastric pouch and the excluded stomach allows for EUS-guided transgastric interventions (EDGIs) in patients with Roux-en-Y gastric bypass (RYGB). Although EUS-guided transgastric ERCP (EDGE) outcomes have been reported, data are scant on other endoscopic interventions. We aimed to evaluate the outcomes and safety of EDGIs. This retrospective study involved 9 centers (United States, 8; Europe, 1) and included patients with RYGB who underwent EDGIs between June 2015 and September 2021. The primary outcome was the technical success of EDGIs. Secondary outcomes were adverse events (AEs), length of hospital stay, and fistula follow-up and management. Fifty-four EDGI procedures were performed in 47 patients (mean age, 61 years; 72% women), most commonly for the evaluation of a pancreatic mass (n= 16) and management of pancreatic fluid collections (n= 10). A 20-mm LAMS was used in 26 patients and a 15-mm LAMS in 21, creating a gastrogastrostomy in 37 patients and jejunogastrostomy in 10. Most patients (n= 30, 64%) underwent a dual-session EDGI, with a median interval of 17 days between the 2 procedures. Single-session EDGI was performed in 17 patients, of whom 10 (59%) had anchoring of the LAMS. The most common interventions were diagnostic EUS (with or without FNA or fine-needle biopsy sampling; n= 28) and EUS-guided cystgastrostomy (n= 8). The mean procedural time was 97.6 ± 78.9 minutes. Technical success was achieved in 52 patients (96%). AEs occurred in 5 patients (10.6%), of which only 1 AE (2.1%) was graded as severe. Intraprocedural LAMS migration was the most common AE, occurring in 3 patients (6.4%), whereas delayed spontaneous LAMS migration occurred in 2 (4.3%). Four of the 5 LAMS migration events were managed endoscopically, and 1 required surgical repair. LAMS anchoring was found to be protective against LAMS migration (P= .001). The median duration of hospital stay was 2.1 ± 3.7 days. Of the 17 patients who underwent objective fistula assessment endoscopically or radiologically after LAMS removal, 2 (11.7%) were found to have persistent fistulas. In 1 case the fistula was intentionally left open to assist with weight gain. The other fistula was successfully closed endoscopically. EDGI is effective and safe for the diagnosis and management of pancreaticobiliary and foregut disorders in RYGB patients. It is associated with high rates of technical success and low rates of severe AEs. LAMS migration is the most common AE with evidence that anchoring can be protective against its occurrence. Persistent fistulas may occur, but endoscopic closure seems to be effective.

Clinical utility of linear endosonography in patients with unexplained biliary dilatation and negative MRCP, with predictors for detection of neoplastic lesions

Background and study aimsUnexplained biliary dilatation (UBD) frequently represents a diagnostic dilemma. Linear endosonography (EUS), with its close proximity to the pancreaticobiliary system and the ability for tissue acquisition, could have a role in revealing etiologies of UBD particularly in the context of negative other non-invasive modalities. However, in such patients, the decision for this semi-invasive procedure is usually debatable and often needs justification. Thus, we aimed to evaluate the diagnostic utility of linear EUS in patients with UBD after negative magnetic resonance cholangiopancreatography (MRCP) and to delineate predictors for EUS ability to detect neoplastic lesions.Patients and methodsThis was a prospective diagnostic observational study between 2018 and 2021. Included patients with evidence of biliary dilatation on abdominal ultrasound and negative MRCP underwent linear EUS examination. Results were compared to the final diagnosis relied on histopathology after EUS-guided biopsy or surgery for neoplastic lesions, while ERCP, diagnostic EUS criteria plus histopathology for autoimmune pancreatitis, Rosemont criteria for chronic pancreatitis, and/or follow-up for 6 months were the gold standard tests for non-neoplastic etiologies. Logistic regression was conducted to reveal predictors of neoplasm detection by EUS.ResultsSixty-one patients (mean age 60 years, 32 females) were enrolled; 13.1% of them were asymptomatic. The final diagnosis was categorized into 29 patients with and 32 without neoplasms. Sensitivity, specificity, positive, negative predictive values (PPV, NPV), and accuracy of EUS-positive findings were 98.3%, 100%, 100%, 66.7%, and 98.3%, respectively. Corresponding results for neoplasm identification were 100%, 93.8%, 93.5%, 100%, and 96.7%, respectively. The most common neoplastic etiologies were small pancreatic and ampullary masses. Common bile duct (CBD) diameter > 12.9mm and CA19-9 > 37.1 u/ML were independent predictors for pancreaticobiliary neoplasm at multivariate regression analysis.ConclusionLinear EUS appears to have a high accuracy in detecting etiologies of UBD, with higher sensitivity for small pancreatic, ampullary lesions, and CBD stones. CBD diameter > 12.9 mm and elevated CA19-9 > 37.1 u/ML should raise a concern about the presence of occult pancreaticobiliary neoplasm, and then, EUS may be warranted even in asymptomatic patients.

S0054 Gaining an EDGE: A Single Center Experience with EUS-Directed Transgastric ERCP and EUS

INTRODUCTION: Roux-en-Y anatomy presents a unique challenge for patients needing ERCP or upper EUS. EUS-directed transgastric ERCP (EDGE) is an alternative to laparoscopy- or enteroscopy-assisted ERCP for these patients. Successful diagnostic upper EUS via this approach has been reported as well. We reviewed EDGE procedures performed at our center to measure technical and clinical success, and identify factors potentially associated with stent migration. METHODS: Demographics and procedure data were collected by chart review for patients undergoing EDGE procedures from February 2018 to November 2019. Technical success was defined as access to the excluded stomach following lumen apposing metal stent (LAMS) placement. Clinical success was defined as successful performance of ERCP or EUS either at the index procedure (single stage) or after fistula maturation (two stage). Change in weight was recorded for the duration the LAMS was in place. Fisher’s Exact Test was used to compare rates of stent migration between patients undergoing EDGE with 15 mm and 20 mm LAMSs, via gastro-gastric and entero-gastric routes, and as a single or two stage procedure. RESULTS: 32 EDGE procedures were performed in 29 patients (Table 1). Technical success was seen in 31 of 32 procedures (96.9%). Clinical success was seen in 27 of 32 procedures (84.4%). 19 stents were removed after an average of 59.7 days and the average weight change from stent placement to removal was -2.4 kg. Stent migration occurred in 8/32 (25%) procedures (Table 2). There was no significant difference in rates of migration between 15 mm and 20 mm stents (35.7% vs 17.6%; P = 0.41), between gastro-gastric, and entero-gastric routes (26.1% vs 22.2%; P = 1) and between single and two session EDGE (25% vs 26.7%; P = 1). Serious adverse events attributable to EDGE occurred in 2/32 procedures (6.2%) both of which were occurrences of stent migration requiring surgery. CONCLUSION: Our study supports the previously seen high clinical success rate for EUS guided transgastric access for ERCP and EUS. With the caveat of a small sample size, we did not see a significant difference in stent migration between single and two session procedures. This may support the decision to perform ERCP in the same session as fistula creation, particularly with time sensitive indications like acute cholangitis. Larger studies are needed to identify patient and procedural factors which may contribute to stent migration and other adverse events in EDGE.Table 1.: Patient and Procedure Characteristics.Table 2.: Stent Migration Characteristics.

Adverse events and mortality: comparative analysis between diagnostic and interventional endoscopic ultrasound

Background and aims Escalating an indication of EUS for diagnosis and treatment justifies the evaluation of the conditions associated with the adverse events (AE) and related deaths. The aim is to evaluate and compare the incidence of AE and deaths after diagnostic-EUS (D-EUS) and interventional-EUS (I-EUS). Methods This retrospective study included patients undergoing D-EUS and I-EUS, in two centers for 28 years (03/1992 to 12/2019). Were noted parameters such as: age, gender, indication of EUS, modality, time of occurrence and severity of AE, type of treatment imposed and whether there was death. Descriptive analysis was performed using means, standard deviation and frequencies of the variables of interest. Results 13,196 procedures performed, 9843 D-EUS and 3353 I-EUS. Thirty-seven (0.3%) had AE with six deaths (0.04%). The overall rate of AE for D-EUS and I-EUS was 0.08% and 0.86%, respectively (p > .05). Three deaths (0.03%) occurred after D-EUS and three (0.09%) after I-EUS. AE were immediate and early in 70% and 30%, respectively, with no late complications. Perforation was detected immediately in 80% and early in 20%, being more frequent after D-EUS than I-EUS. Acute pancreatitis occurred immediately in 70% and early in 30%. The AE were mild, moderate, and severe in 35.1%, 27%, and 37.8%, respectively. Overall, D-EUS presented the majority of AE as severe (87.5%), while I-EUS presented mild AE in most cases (41.4%), followed by severe complications (24.1%). Conclusions Despite the low incidence of AE and mortality after EUS, the occurrence of severe complications, especially perforation in D-EUS, may support the review of therapeutic protocols, aiming to ensure that a quality and safety process is implemented in the practice of EUS.

Sa1426 DIAGNOSTIC YIELD AND CLINICAL PREDICTORS OF SIGNIFICANT FINDINGS OF ENDOSCOPIC ULTRASOUND IN EVALUATING ASYMPTOMATIC COMMON BILE DUCT DILATION WITH NORMAL LIVER FUNCTION TESTS

While EUS is highly sensitive and specific for the evaluation of common bile duct (CBD) dilation, its yield in asymptomatic patients with normal liver function tests (LFTs) is unclear. To assess the diagnostic yield of EUS, to identify predictors of a pathologic finding, and to create a risk stratification model to aid clinical decision making in patients with incidental CBD dilation found on imaging with normal LFTs. We performed a retrospective review of patients with unexplained CBD dilation on abdominal ultrasound, CT, or MRI/MRCP who underwent EUS at an academic medical center between 2009 and 2019. After excluding patients with right upper quadrant pain, known pancreaticobiliary disease, obvious cause of CBD dilation on imaging, or elevated LFTs, n=288 patients were identified for analysis. Univariate and multivariate analyses were used to identify predictors of findings on EUS. We used backward stepwise selection based on the corrected Akaike information criterion to select the variables included the multivariate analysis. Using the results of our multivariate analysis, we created a risk prediction model to determine the probability of a pathologic finding on EUS. Of the 288 patients, 29 (10.1%) had significant findings: 21 had choledocholithiasis or sludge (7.3%), 3 had ampullary pathology (1%), 2 had head of pancreas masses (0.7%), and 3 had other causes (1%). On univariate analysis, factors associated with a pathologic finding on EUS were age ≥70 (OR 3.31 (1.45, 7.56)), non biliary-type abdominal pain (OR 2.3 (1.05, 5.1)), CBD ≥14 mm on index imaging (4.91 (2.11, 11.45)), and history of ERCP (3.27 (1.32, 8.11)). Using multivariate regression, predictive factors affecting a diagnostic EUS were age ≥70 (OR 3.79 (1.53, 10.12)), non-biliary type abdominal pain (OR 3.28 (1.29, 8.95)), CBD ≥14 mm on index imaging (6.46 (2.53, 17.64)), history of ERCP (OR 3.04 (0.93, 9.18)), and history of cholecystectomy (OR 0.43 (0.16, 1.14). The overall AUC of the model was 0.797. Using the coefficients for each variable, a score was assigned to each to create a clinical prediction model to predict the chance of a pathologic finding on EUS: age ≥70 = 1, non-biliary type abdominal pain = 1, history of ERCP = 1, CBD ≥14 mm on index imaging = 2, and history of a cholecystectomy = -1. A total score of ≤1 predicts a <5% chance of having a significant finding (Figure). Only 10% of patients undergoing EUS for asymptomatic CBD dilation had pathologic findings. Age ≥70, CBD ≥14 on cross sectional imaging, non-biliary type abdominal pain, and a history of prior ERCP predicted a pathologic finding on EUS, while history of a cholecystectomy predicts no finding on EUS. We created a novel clinical prediction model to aid in the utilization of EUS in this context which will require independent, external validation.Figure 1Predicted probability of a significant finding on EUS based on clinical prediction model score.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

3030 Klatskin Tumor: Dive in to Take a Closer Look…

INTRODUCTION: Malignant tumors of the biliary tract are rare and highly lethal. Further sub classification of Cholangiocarcinomas defines Klatskin tumors, as extrahepatic bile duct tumors involving the hepatic duct bifurcation with distinct finding on dedicated imaging. CASE DESCRIPTION/METHODS: An 80-years-old former smoker female was referred by outpatient neurologist for unintentional 30-40 lb weight loss over 6 months, jaundice and abnormal LFTs. Her examination was unremarkable. Patient was found to have abnormal LFTswith ALP of 1210 U/L, GGT 1350 U/L, AST 388 U/L, ALT 300 U/L, TB 2.5 mg/dL (DB of 2.1 mg/dL). Tumor markers were grossly normal including CA 19-9 of 5 U/ml, CEA of 5 ng/mL and AFP of 5 ng/ml. CT abdomen and pelvis with IV contrast showed moderate to significant intrahepatic biliary ductal dilatation with a caliber change at the level of the porta hepatis, where there is abnormal soft tissue extending centrally to the liver. These findings are worrisome for Klatskin type tumor. Diagnostic EUS was started, however aborted once an infiltrating mass found in the gastric body causing luminal gastric narrowing restricting passage of EUS scope. Biopsies obtained from gastric mass, showed adenocarcinoma, poorly differentiated with signet-ring cell features and Helicobacter pylori positive stain. DISCUSSION: Despite progress, gastric cancers in the United States are still being diagnosed at an advanced stage, when become symptomatic and often incurable stage. Unintentional weight loss, early satiety and occasionally vague epigastric pain are often the presenting symptoms of an already advanced cancer. Gastric ulcers and H. Pylori infection have been shown to be precursors with potential carcinogenic effect. More unusual presentations give signs and symptoms secondary to direct extension of the tumor to nearby organs (most common to liver), or distant metastases to liver, peritoneum, Virchow's node (Supraclavicular lymph node), Periumbilical nodule (Sister Mary Joseph's node, or a left axillary node (Irish node). When metastases to liver are present, they are often diffuse or multifocal and rarely unifocal. Our case is interesting as the initial CT imaging was highly suggestive of a rare and lethal Klatskin tumor type of cholangiocarcinoma. The final decision to pursue a tissue diagnosis with a high risk procedure (EUS) was aborted by a surprising finding of a locally advanced gastric adenocarcinoma.

The EDGI new take on EDGE: EUS-directed transgastric intervention (EDGI), other than ERCP, for Roux-en-Y gastric bypass anatomy: a multicenter study.

Background and study aims Indications for accessing the duodenum, and/or excluded stomach in Roux-en-Y gastric bypass (RYGB) patients extend beyond diagnosis and treatment of pancreaticobiliary maladies. Given the high technical and clinical success of EUS-directed transgastric ERCP (EDGE) in RYGB anatomy, we adopted this transgastric (anterograde) approach to evaluate and treat luminal and extraluminal pathology in and around the excluded gut in RYGB patients. EUS-directed transgastric intervention (“EDGI”), other than ERCP, is the terminology we have chosen to describe this heterogenous group of transgastric diagnostic and/or interventional endoscopic procedures (transgastric interventions) performed via a lumen-apposing mental stent (LAMS) in select patients with RYGB. Patients and methods A multicenter (n = 4), retrospective study of RYGB patients with suspected luminal or extraluminal pathology, in or around the duodenum and/or excluded stomach, underwent EDGI using LAMS between December 2015 and January 2019. Results A total of 14 patients (78.6 % women; mean age, 55.7 + 12.4 years) underwent EDGI via LAMS. Technical and clinical success rates of EDGI were 100 %. The most common transgastric interventions were diagnostic EUS of extraluminal pathology (n = 6, 42.7 %) and endoscopic biopsy of gastroduodenal luminal abnormalities (n = 5, 35.7 %). Two moderate-severity adverse events due to LAMS maldeployment occurred during EUS-JG creation (14.3 %), and each instance was successfully rescued with a bridging stent. Conclusions A variety of gastroduodenal luminal and extraluminal disorders in RYGB patients can be effectively diagnosed and managed using EDGI via LAMS.

How I do a diagnostic EUS.

How I do a diagnostic EUS.

Endoscopic management of pancreatic fluid collections.

Pancreatic fluid collections (PFCs) are common complications of acute pancreatitis. Asymptomatic collections do not require drainage while symptomatic or infected collections should be drained. Drainage can be performed surgically, percutaneously, or endoscopically. Recent studies have shown that endoscopic drainage of PFCs is equivalent or superior to surgical or percutaneous drainage, with less complications. Advances in tools and technology coupled with increasing expertise in management of PFCs has resulted in minimally invasive endoscopic drainage, by endosonographic guidance, being the preferred approach. New larger diameter lumen apposing metal stents (LAMS) have simplified the process of drainage. LAMS have also made performing direct endoscopic necrosectomy for walled-off necrosis (WON) easier. Technique, duration, frequency, and tools used for direct endoscopic necrosectomy are variable. Performing PFC drainage requires adequate and fundamental knowledge of diagnostic and basic therapeutic EUS.

Evaluation of a new slim radial echoendoscope: A better option for an aging population.

Background and Objectives:The radial echoendoscope is still widely used for the investigation of abnormalities in the gastrointestinal wall and for stone detection in the extrahepatic biliary tree. Due to aging patient population, EUS is frequently performed in fragile and elderly individuals. We aimed to compare the maneuverability and image quality of a new thin radial echoendoscope to the current one.Patients and Methods:This evaluation was conducted at a referral academic EUS center. The new radial echoendoscope has a thinner shaft and distal tube and a shorter bending section compared to the previous one. Patients referred for diagnostic EUS with a radial echoendoscope were enrolled. Indications included pancreaticobiliary disease, esophagogastric abnormalities, and neoplasms and rectal cancer staging.Results:We enrolled 177 patients (122 pancreaticobiliary, 48 esophagogastric, and 7 rectal cases). Overall, the new echoendoscope performed better than the previous model in terms of maneuverability during esophageal intubation and transition from the duodenal bulb to the second portion. On the other hand, pylorus traversing was comparable to the current radial echoendoscope. No loss in image quality was appreciated at predefined stations (esophagus, stomach, and duodenum) compared to the current model. On the other hand, image penetration depth in tissue harmonic mode was significantly improved with the new echoendoscope.Conclusions:A new thinner radial echoendoscope showed improved maneuverability compared to the existing version. Image quality was also improved thanks to increased penetration depth in the tissue harmonic mode. We speculate that this new echoendoscope may allow for safer and faster EUS examination, which may prove useful in an aging patient population.

Endoscopic Ultrasound-Guided Tissue Acquisition: Techniques and Challenges.

Endoscopic ultrasound-guided fine needle aspiration (EUS FNA) has made pathological diagnosis of pancreatic neoplasms, diseases involving lymph nodes at various mediastinal and abdominal sites, gastrointestinal submucosal lesions, perirectal lesions, adrenal lesions, and mediastinal masses easy. EUS-guided FNA is a multistep procedure that involves assessment of proper clinical indication, correct selection of FNA needles, and adoption of evidence-based techniques for tissue sampling. EUS FNA is done by needles that are available in different sizes, mainly 25, 22, and 19-gauge needle. The need of onsite cytopathologist, dependence on histology/core biopsy occasionally to get a diagnosis, and inability to reliably assess for molecular markers are important limitations of EUS FNA. EUS-guided fine needle biopsy (FNB) that samples the core of tissue is an exciting new development in the field of diagnostic EUS. FNB needles are expensive than FNA needles, and although the initial results are encouraging, more studies with robust evidence proving their superiority beyond any doubt are needed before they can be widely used.

Safety of ERCP and EUS Procedures in Cirrhotic Patients

Introduction: Therapeutic ERCP and diagnostic EUS procedures are associated with known risks. These risks may be greater in patients with hepatic cirrhosis given the sequelae associated with decreased hepatic synthetic function. We sought to examine whether the severity of cirrhosis was associated with greater incidence of adverse events. Methods: We performed a retrospective study of all patients diagnosed with hepatic cirrhosis who underwent ERCP or EUS-guided FNA/FNB from July 2016 to April 2018 at our safety net hospital. We reviewed the etiology for cirrhosis, Child-Pugh and MELD-Na scores at the time of procedure, indications for procedure, interventions completed, and 30-day post-procedural adverse events. Statistical analysis was done to assess whether Child-Pugh class and MELD-Na score were associated with greater adverse event rates and whether advanced techniques, defined as electrohydraulic lithotripsy (EHL), laser lithotripsy, or needle-knife techniques, were associated with higher rates of complications. Results: 50 procedures (40 ERCP, 10 EUS-FNA/FNB) performed on 22 patients were included. 18 cases were classified as Child's A, 22 cases as Child's B, and 10 cases as Child's C. Mean MELD-Na score was 14.1. Cirrhosis was documented as being secondary to pyogenic cholangitis (n=11), NASH (n=9), malignancy (n=2), alcoholism (n=20), HBV (n=9), HCV (n=4), PBC (n=1), AIH (n=2), and cryptogenic (n=2). Interventions included EHL (n=11), stent placement/removal (n=31), stone removal (n=24), Spyglass cholangioscopy (n=18), spincterotomy (n=11), laser lithotripsy (n=4), FNA/FNB biopsies (n=7), liver biopsy (n=3), needle-knife techniques (n=6), and papillotomy (n=2). 30-day procedurerelated adverse events occurred in 12 cases and included fever (n=3), upper GI bleed (n=4), bacteremia (n=3), septic shock (n=1), bile leak (n=1), stent migration (n=1), retroperitoneal hematoma (n=1), and death (n=3). Both Child-Pugh class and MELD-Na score were significant predictors of adverse events (p=0.045, p=0.011 respectively). Advanced techniques were not associated with increased event rates (p>0.05). Conclusion: Consistent with established literature, our study demonstrates that severity of cirrhosis, as defined by Child-Pugh class and MELD-Na score, are associated with increased rates of adverse events in invasive procedures. However, the rate of adverse events appears to be unaffected by the use of advanced techniques with ERCP/EUS procedures among cirrhotic patients overall.