Impact of preoperative endoscopic procedures on adverse event rates after surgical resection for main-duct and mixed-type intraductal papillary mucinous neoplasms (IPMNs).

BACKGROUND: Main-duct (MD-) and mixed-type (MT-) IPMNs harbor an increased risk of pancreatic cancer and warrant surgical resection. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are important in the diagnosis of IPMNs. The aim of this study was to investigate whether endoscopic procedures manipulating the MD impact postoperative adverse events in patients with MD- and MT-IPMNs. METHODS: We performed a retrospective study of 369 patients who underwent resections for MD- or MT-IPMN at two tertiary centers (2000-2019). Multivariable logistic regression analyses were performed for postoperative adverse events to compare the risks between intervention (ERCP, EUS-FNA with branch duct (BD) aspirated, EUS-FNA with MD aspirated from the duct directly or cyst/mass arising from MD) versus no-intervention group. RESULTS: 33.1 % of patients had a preoperative ERCP and 69.4 % had EUS-FNA. Postoperative adverse events included: 30-day readmission (12.7 %), delayed gastric emptying (13.8 %), pancreatic fistula (10.3 %), abdominal abscess (5.7 %), cardiopulmonary adverse events (11.4 %), and mortality (1.4 %). The model was adjusted for potential confounders. There were no significant differences between the ERCP and no-ERCP groups for specific adverse events. Compared to no-EUS-FNA groups, groups of EUS-FNA with BD aspiration and EUS-FNA with MD aspiration from the main pancreatic duct directly or cyst/mass arising from MD did not show a significant increase in specific adverse events. CONCLUSIONS: Postoperative adverse events were not significantly increased among patients who had ERCP or EUS-FNA before surgical resection for MD- or MT-IPMNs. Endoscopic procedures directly sampling the MD can be safely pursued for diagnostic purposes in selected cases.

Isolation, Expansion, and Endoscopic Delivery of Autologous Enteric Neuronal Stem Cells in Swine.

The enteric nervous system (ENS) is an extensive network of neurons and glia within the wall of the gastrointestinal (GI) tract that regulates many essential GI functions. Consequently, disorders of the ENS due to developmental defects, inflammation, infection, or age-associated neurodegeneration lead to serious neurointestinal diseases. Despite the prevalence and severity of these diseases, effective treatments are lacking as they fail to directly address the underlying pathology. Neuronal stem cell therapy represents a promising approach to treating diseases of the ENS by replacing the absent or injured neurons, and an autologous source of stem cells would be optimal by obviating the need for immunosuppression. We utilized the swine model to address key questions concerning cell isolation, delivery, engraftment, and fate in a large animal relevant to human therapy. We successfully isolated neural stem cells from a segment of small intestine resected from 1-month-old swine. Enteric neuronal stem cells (ENSCs) were expanded as neurospheres that grew optimally in low-oxygen (5%) culture conditions. Enteric neuronal stem cells were labeled by lentiviral green fluorescent protein (GFP) transduction, then transplanted into the same swine from which they had been harvested. Endoscopic ultrasound was then utilized to deliver the ENSCs (10,000-30,000 neurospheres per animal) into the rectal wall. At 10 and 28 days following injection, autologously derived ENSCs were found to have engrafted within rectal wall, with neuroglial differentiation and no evidence of ectopic spreading. These findings strongly support the feasibility of autologous cell isolation and delivery using a clinically useful and minimally invasive technique, bringing us closer to first-in-human ENSC therapy for neurointestinal diseases.

A Multi-Institutional Safety and Feasibility Study Exploring the Use of Hydrogel to Create Spatial Separation between the Pancreas and Duodenum in Patients with Pancreatic Cancer.

PURPOSE: The administration of dose-escalated radiation for pancreatic adenocarcinoma remains challenging because of the proximity of dose-limiting stomach and bowel, particularly the duodenum for pancreatic head tumors. We explore whether endoscopic injection of a temporary, absorbable hydrogel into the pancreatico-duodenal (PD) groove is safe and feasible for the purpose of increasing spatial separation between pancreatic head tumors and the duodenum. METHODS AND MATERIALS: Six patients with localized pancreatic adenocarcinoma underwent endoscopic injection of hydrogel into the PD groove. Safety was assessed based on the incidence of procedure-related adverse events resulting in a delay of radiation therapy initiation. Feasibility was defined as the ability to create spatial separation between the pancreas and duodenum, as assessed on simulation CT. RESULTS: All 6 patients were able to undergo endoscopic injection of hydrogel into the PD groove. No device-related events were experienced at any point in follow-up. Presence of hydrogel in the PD groove was apparent on simulation CT in all 6 patients. Mean space created by the hydrogel was 7.7 mm +/- 2.4 mm. In 3 patients who underwent Whipple resection, presence of hydrogel in the PD groove was pathologically confirmed with no evidence of damage to the duodenum. CONCLUSIONS: Endoscopic injection of hydrogel into the PD groove is safe and feasible. Characterization of the dosimetric benefit that this technique may offer in the setting of dose-escalated radiation should also be pursued, as should the ability of such dosimetric benefit to translate into clinically improved tumor control.

"Evolving Trends in Pancreatic Cystic Tumors: A 3-Decade Single-Center Experience With 1290 Resections".

OBJECTIVE: The aim of this study was to describe our institutional experience with resected cystic tumors of the pancreas with emphasis on changes in clinical presentation and accuracy of preoperative diagnosis. SUMMARY BACKGROUND DATA: Incidental discovery of pancreatic cystic lesions has increased and has led to a rise in pancreatic resections. It is important to analyze surgical outcomes from these procedures, and the prevalence of malignancy, pre-malignancy and resections for purely benign lesions, some of which may be unintended. METHODS: Retrospective review of a prospective database spanning 3 decades. Presence of symptoms, incidental discovery, diagnostic studies, type of surgery, postoperative outcomes, and concordance between presumptive diagnosis and final histopathology were recorded. RESULTS: A total of 1290 patients were identified, 62% female with mean age of 60 years. Fifty-seven percent of tumors were incidentally discovered. Ninety-day operative mortality was 0.9% and major morbidity 14.4%. There were 23 different diagnosis, but IPMN, MCN, and serous cystadenoma comprised 80% of cases. Concordance between preoperative and final histopathological diagnosis increased by decade from 45%, to 68%, and is presently 80%, rising in parallel with the use of endoscopic ultrasound, cytology, and molecular analysis. The addition of molecular analysis improved accuracy to 91%. Of misdiagnosed cases, half were purely benign and taken to surgery with the presumption of malignancy or premalignancy. The majority of these were serous cystadenomas. CONCLUSIONS: Indications and diagnostic work-up of cystic tumors of the pancreas have changed over time. Surgical resection can be performed with very low mortality and acceptable morbidity and diagnostic accuracy is presently 80%. About 10% of patients are still undergoing surgery for purely benign lesions that were presumed to be malignant or premalignant. Further refinements in diagnostic tests are required to improve accuracy.

Multi-society consensus conference and guideline on the treatment of gastroesophageal reflux disease (GERD).

BACKGROUND: Gastroesophageal reflux disease (GERD) is one of the most common diseases in North America and globally. The aim of this guideline is to provide evidence-based recommendations regarding the most utilized and available endoscopic and surgical treatments for GERD. METHODS: Systematic literature reviews were conducted for 4 key questions regarding the surgical and endoscopic treatments for GERD in adults: preoperative evaluation, endoscopic vs surgical or medical treatment, complete vs partial fundoplication, and treatment for obesity (body mass index [BMI] ≥ 35 kg/m2) and concomitant GERD. Evidence-based recommendations were formulated using the GRADE methodology by subject experts. Recommendations for future research were also proposed. RESULTS: The consensus provided 13 recommendations. Through the development of these evidence-based recommendations, an algorithm was proposed for aid in the treatment of GERD. Patients with typical symptoms should undergo upper endoscopy, manometry, and pH-testing; additional testing may be required for patients with atypical or extra-esophageal symptoms. Patients with normal or abnormal findings on manometry should consider undergoing partial fundoplication. Magnetic sphincter augmentation or fundoplication are appropriate surgical procedures for adults with GERD. For patients who wish to avoid surgery, the Stretta procedure and transoral incisionless fundoplication (TIF 2.0) were found to have better outcomes than proton pump inhibitors alone. Patients with concomitant obesity were recommended to undergo either gastric bypass or fundoplication, although patients with severe comorbid disease or BMI > 50 should undergo Roux-en-Y gastric bypass for the additional benefits that follow weight loss. CONCLUSION: Using the recommendations an algorithm was developed by this panel, so that physicians may better counsel their patients with GERD. There are certain patient factors that have been excluded from included studies/trials, and so these recommendations should not replace surgeon-patient decision making. Engaging in the identified research areas may improve future care for GERD patients.

Concordance of EUS and MRI/MRCP findings among high-risk individuals undergoing pancreatic cancer screening.

BACKGROUND/OBJECTIVES: Surveillance with endoscopic ultrasonography (EUS) and MRI/magnetic retrograde cholangiopancreatography (MRCP) is recommended for individuals at high risk for pancreatic cancer. We sought to characterize the findings of these surveillance exams and define the level of concordance between these two modalities. METHODS: 173 asymptomatic high-risk individuals (HRIs) meeting criteria for pancreatic cancer surveillance underwent EUS, MRI/MRCP, or both between 2008 and 2021. Clinical records were reviewed in all cases. RESULTS: HRIs underwent an average of 3.6 ± 3.2 surveillance exams over a period of 3.3 ± 3.5 years. Abnormalities including intraductal papillary mucinous neoplasms (IPMNs), solid lesions, and parenchymal irregularities were identified in 50.9% (n = 88). Four of these abnormalities (2.3%) had worrisome features, defined by cyst size, thickened/enhancing cyst walls, rapid growth rate, or change in main pancreatic duct diameter. All four worrisome lesions were seen on both MRI/MRCP and EUS. No pancreatic cancers were detected. Baseline EUS and MRI/MRCP exams were compared in 106 patients for concordance, and most (n = 66, 62.3%) were concordant. High levels of concordance were specifically observed for a dilated main pancreatic duct (p < 0.01) and cystic lesions >5 mm (p = 0.01). Among discordant cases, most (30/40; 75%) involved abnormal tissue heterogeneity seen primarily on EUS. None of these discordant lesions ultimately developed worrisome features. CONCLUSIONS: Worrisome pancreatic lesions were uncommon in our high-risk pancreatic cancer population and were detected by both EUS and MRI/MRCP. There was mild discordance with respect to less worrisome findings, but these discrepancies were not associated with any adverse clinical outcomes.

Next-generation sequencing in the evaluation of biliary strictures in patients with primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a well-described risk factor for the development of cholangiocarcinoma (CCA). Early detection of CCA in these patients is of great importance because it expands options for therapeutic interventions, including liver transplantation. Current diagnostic tests for the evaluation of biliary strictures are limited to biliary brushing (BB) cytology and fluorescence in situ hybridization (FISH). Next-generation sequencing (NGS) has become an important diagnostic tool in oncology and may be a useful tool for diagnosing CCA on BBs. It is not clear how NGS performs when it is added to BB cytology and FISH in patients with PSC. METHODS: This study reports the authors' experience with NGS performed as a prospective cotest with cytology and FISH on BBs obtained from 60 patients with PSC followed at Massachusetts General Hospital. A duct with malignancy was defined as a high-risk (HR) stricture with either high-grade dysplasia or CCA. RESULTS: NGS was better than FISH and cytology in detecting HR strictures, which showed multiple genetic mutations in all cases. NGS provided specific mutational information, and NGS results were reproducible in longitudinal samples. CONCLUSIONS: Adding NGS to BB cytology and FISH in the evaluation of biliary strictures for patients with PSC may provide additional information that could help to inform clinical management.

Endoscopic polypectomy devices.

Video 1Use of submucosal injection prior to en-bloc endoscopic mucosal resection.Video 2Use of a detachable loop ligating device prior to hot snare resection of a pedunculated polyp.

Lumen-apposing metal stents (with videos).

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) are a novel class of devices that have expanded the spectrum of endoscopic GI interventions. LAMSs with their dumbbell configuration, short saddle length, and large inner luminal diameter provide favorable stent characteristics to facilitate anastomosis formation between the gut lumen and adjacent structures. METHODS: The MEDLINE database was searched through April 2021 for articles related to LAMSs by using additional relevant keywords such as "walled-off pancreatic necrosis," "pseudocysts," "pancreatic fluid collection," "cholecystitis," "gastroenterostomy," in addition to "endoscopic treatment" and "endoscopic management," among others. RESULTS: This technology review describes the full spectrum of LAMS designs and delivery systems, techniques for deployment, procedural outcomes, safety, training issues, and financial considerations. CONCLUSIONS: Although LAMSs were initially introduced for drainage of pancreatic pseudocysts and walled-off necrosis, the versatility of these devices has led to a variety of off-label uses including gallbladder drainage, enteric bypass with the creation of gastroenterostomies, and treatment of luminal GI strictures.

Pancreatic acinar cell carcinoma: A multi-center series on clinical characteristics and treatment outcomes.

BACKGROUND: Acinar cell carcinoma (ACC) is a very rare tumor of the exocrine pancreas, representing less than 1% of all pancreatic malignancies. The majority of data regarding ACC are limited to small case series. METHODS: This is a retrospective study conducted at a large healthcare system from 1996 to 2019. Patients with pathologically confirmed ACC were included, and demographic data, tumor characteristics, and treatment outcomes were abstracted by chart review. Survival curves were obtained by using the Kaplan-Meier method and compared using the log-rank test. RESULTS: Sixty-six patients with ACC were identified. The median patient age at diagnosis was 64, and 42% presented with metastatic disease. The majority presented with abdominal pain or pancreatitis (69%), and laboratory parameters did not correlate with tumor size, metastatic disease, or survival. Several somatic abnormalities were noted in tumors (BRCA2, TP53, and mismatch-repair genes). In patients with localized disease that underwent resection, the median time to develop metastatic lesions was 13 months. The median overall survival (OS) was 24.7 months from diagnosis, with a survival difference based on metastatic disease at diagnosis (median 15 vs 38 mos). Surgery was associated with improved survival in non-metastatic cases (p = 0.006) but not metastatic cases (p = 0.22), and chemotherapy showed OS benefit in metastatic disease (p < 0.01). Patients with metastatic ACC treated after 2010 utilized more platinum-based agents, and there was a OS benefit to FOLFOX or FOLFIRINOX chemotherapy compared to gemcitabine or capecitabine-based regimens (p = 0.006). CONCLUSION: Pancreatic ACC patients often present with advanced disease. Surgery was associated with survival benefit among patients presenting with localized disease. The use of FOLFOX or FOLFIRINOX chemotherapy regimens was associated with improved OS in metastatic patients. These data add to our knowledge in this rare malignancy, and improves understanding about the genomic underpinnings, prognosis and treatment for acinar cancers.

Preoperative cholangitis is an independent risk factor for mortality in patients after pancreatoduodenectomy for pancreatic cancer.

OBJECTIVES: Preoperative biliary stenting is required for patients with obstructive jaundice from pancreatic adenocarcinoma who are receiving neoadjuvant chemotherapy. While in most patients this approach results in durable biliary drainage, some patients develop cholangitis during neoadjuvant treatment. Further, several studies have shown that preoperative cholangitis in patients with hepatobiliary malignancies can result in substantially unfavorable outcomes. The aim of this study was to evaluate the impact of preoperative cholangitis in patients who underwent pancreaticoduodenectomy after completing neoadjuvant chemotherapy. METHODS: Participants: all adult patients (n = 449) diagnosed with pancreatic adenocarcinoma from January 1st, 2013 to March 31st, 2018 who pursued treatment at the Massachusetts General Hospital were screened. Of these 449 patients, 97 met final inclusion criteria of receiving neoadjuvant chemotherapy with intent to pursue curative surgery. Data were collected via retrospective chart review including baseline characteristics, survival, episodes of preoperative cholangitis, and surgical complications. RESULTS: In patients completing successful pancreaticoduodenectomy surgery, preoperative cholangitis is associated with increased mortality (HR 2.67, 95% CI:1.16-6.13). This finding is independent of postoperative outcomes or tumor recurrence rate. The presence of cholangitis did not impact completion of neoadjuvant chemotherapy (92% vs 85%, p = 0.5) or ability to proceed to surgery (76% vs 75%, p = 1.0). Preoperative cholangitis was not associated with postoperative morbidity (42.1% vs 45.1%, p = 1.0). CONCLUSIONS: One episode of cholangitis during neoadjuvant chemotherapy is associated with increased mortality following successful pancreaticoduodenectomy, independent of immediate postoperative outcomes or tumor recurrence. Preoperative cholangitis does not affect ability to pursue neoadjuvant chemotherapy or complete successful surgery. Patients who develop cholangitis during the neoadjuvant chemotherapy treatment phase may reflect a distinct phenotype of patients with PDAC with a complex and more challenging clinical course.

Enhanced EUS imaging (with videos).

BACKGROUND AND AIMS: EUS remains a primary diagnostic tool for the evaluation of pancreaticobiliary disease. Although EUS combined with FNA or biopsy sampling is highly sensitive for the diagnosis of neoplasia within the pancreaticobiliary tract, limitations exist in specific clinical settings such as chronic pancreatitis. Enhanced EUS imaging technologies aim to aid in the detection and diagnosis of lesions that are commonly evaluated with EUS. METHODS: We reviewed technologies and methods for enhanced imaging during EUS and applications of these methods. Available data regarding efficacy, safety, and financial considerations are summarized. RESULTS: Enhanced EUS imaging methods include elastography and contrast-enhanced EUS (CE-EUS). Both technologies have been best studied in the setting of pancreatic mass lesions. Robust data indicate that neither technology has adequate specificity to serve as a stand-alone test for pancreatic malignancy. However, there may be a role for improving the targeting of sampling and in the evaluation of peritumoral lymph nodes, inflammatory pancreatic masses, and masses with nondiagnostic FNA or fine-needle biopsy sampling. Further, novel applications of these technologies have been reported in the evaluation of liver fibrosis, pancreatic cysts, and angiogenesis within neoplastic lesions. CONCLUSIONS: Elastography and CE-EUS may improve the real-time evaluation of intra- and extraluminal lesions as an adjunct to standard B-mode and Doppler imaging. They are not a replacement for EUS-guided tissue sampling but provide adjunctive diagnostic information in specific clinical situations. The optimal clinical use of these technologies continues to be a focus of ongoing research.

Artificial intelligence in gastrointestinal endoscopy.

BACKGROUND AND AIMS: Artificial intelligence (AI)-based applications have transformed several industries and are widely used in various consumer products and services. In medicine, AI is primarily being used for image classification and natural language processing and has great potential to affect image-based specialties such as radiology, pathology, and gastroenterology (GE). This document reviews the reported applications of AI in GE, focusing on endoscopic image analysis. METHODS: The MEDLINE database was searched through May 2020 for relevant articles by using key words such as machine learning, deep learning, artificial intelligence, computer-aided diagnosis, convolutional neural networks, GI endoscopy, and endoscopic image analysis. References and citations of the retrieved articles were also evaluated to identify pertinent studies. The manuscript was drafted by 2 authors and reviewed in person by members of the American Society for Gastrointestinal Endoscopy Technology Committee and subsequently by the American Society for Gastrointestinal Endoscopy Governing Board. RESULTS: Deep learning techniques such as convolutional neural networks have been used in several areas of GI endoscopy, including colorectal polyp detection and classification, analysis of endoscopic images for diagnosis of Helicobacter pylori infection, detection and depth assessment of early gastric cancer, dysplasia in Barrett's esophagus, and detection of various abnormalities in wireless capsule endoscopy images. CONCLUSIONS: The implementation of AI technologies across multiple GI endoscopic applications has the potential to transform clinical practice favorably and improve the efficiency and accuracy of current diagnostic methods.

Endoscopic devices and techniques for the management of bariatric surgical adverse events (with videos).

BACKGROUND AND AIMS: As the prevalence of obesity continues to rise, increasing numbers of patients undergo bariatric surgery. Management of adverse events of bariatric surgery may be challenging and often requires a multidisciplinary approach. Endoscopic intervention is often the first line of therapy for management of these adverse events. This document reviews technologies and techniques used for endoscopic management of adverse events of bariatric surgery, organized by surgery type. METHODS: The MEDLINE database was searched through May 2018 for articles related to endoscopic management of adverse events of bariatric interventions by using relevant keywords such as adverse events related to "gastric bypass," "sleeve gastrectomy," "laparoscopic adjustable banding," and "vertical banded sleeve gastroplasty," in addition to "endoscopic treatment" and "endoscopic management," among others. Available data regarding efficacy, safety, and financial considerations are summarized. RESULTS: Common adverse events of bariatric surgery include anastomotic ulcers, luminal stenoses, fistulae/leaks, and inadequate initial weight loss or weight regain. Devices used for endoscopic management of bariatric surgical adverse events include balloon dilators (hydrostatic, pneumatic), mechanical closure devices (clips, endoscopic suturing system, endoscopic plication platform), luminal stents (covered esophageal stents, lumen-apposing metal stents, plastic stents), and thermal therapy (argon plasma coagulation, needle-knives), among others. Available data, composed mainly of case series and retrospective cohort studies, support the primary role of endoscopic management. Multiple procedures and techniques are often required to achieve clinical success, and existing management algorithms are evolving. CONCLUSIONS: Endoscopy is a less invasive alternative for management of adverse events of bariatric surgery and for revisional procedures. Endoscopic procedures are frequently performed in the context of multidisciplinary management with bariatric surgeons and interventional radiologists. Treatment algorithms and standards of practice for endoscopic management will continue to be refined as new dedicated technology and data emerge.

Current status of newer generation endoscopic ultrasound core needles in the diagnostic evaluation of gastrointestinal lesions.

Endoscopic ultrasound-guided tissue acquisition is now an imperative technique for the diagnosis of multiple diseases in the gastrointestinal tract and nearby structures. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and fine needle biopsy via dedicated FNB needles (EUS-FNB) are two standard-essential tools for tissue acquisition. The choice of needle type is an important factor determining appropriate tissue acquisition. Multiple studies have compared EUS-FNA versus EUS-FNB on different lesions also there are several studies evaluated different needles in terms of sampling adequacy and cytological and histological accuracy. Prior studies comparing prior-generation FNB needles to FNA did not show an increased diagnostic yield with FNB. However, the newer-generation needles have demonstrated enhanced performance compared with their predecessors. As they may provide a large amount of tissue for the cytological and histological evaluation, rapid onsite specimen evaluation (ROSE), and immunohistochemical and molecular analyses, which may be very important for targeted therapy. In this review, we discuss current evidence and literature on the use of the newer generation needles for pancreatic and non-pancreatic lesions.

Devices and techniques for endoscopic treatment of residual and fibrotic colorectal polyps (with videos).

BACKGROUND AND AIMS: Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging. METHODS: This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed. RESULTS: Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection. CONCLUSIONS: Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Evaluating triage protocols for endoscopic ultrasound-guided fine needle biopsies of the pancreas.

INTRODUCTION: Pancreatic endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) acquires both direct smear and small core biopsy specimens. The triage protocols for pancreatic FNBs to cytopathology (CP) or gastrointestinal surgical pathology (GIP) are controversial and vary by institution. MATERIAL AND METHODS: Pancreatic EUS-FNBs obtained with the SharkCore FNB were reviewed from January 2014 to June 2019. The specimen characteristics and pathology data, including tissue triage, were obtained from the electronic medical records. We assessed the diagnostic yield, defined as malignant, specific neoplastic, or benign, and the operating characteristics at the time of rapid on-site evaluation (ROSE) and final diagnosis. RESULTS: We reviewed 324 pancreatic FNBs from 313 patients. Of the 324 FNBs, 260 (80%) obtained concurrent direct smear and core biopsy specimens, 30 (12%) of which were divided between CP and GIP. Of the 51 core-only specimens, 47 (92%) were reviewed by CP and 4 (8%) by GIP. ROSE improved the overall diagnostic yield by 10% and accuracy by 9%. When core specimens were reviewed independently, the diagnostic accuracy was 93% for CP (n = 248) and 100% for GIP (n = 33). All false-negative results of the CP-reviewed cores were due to sampling error. Concurrent smear review improved EUS-FNB performance, increasing the negative predictive value by 10% and accuracy by 3% compared with core review alone. CONCLUSIONS: CP and GIP can accurately interpret pancreatic EUS-FNB specimens. However, triage of concurrent EUS-FNB-acquired smear and core specimens to CP may be most efficient as CPs are trained to assess adequacy at the time of ROSE, as well as interpret all parts of the biopsy, minimizing the risk of discordant pathology reports.