Petersen, Bret T.

Objective The diagnosis of autoimmune pancreatitis (AIP) is challenging. Sonographic and cross-sectional imaging findings of AIP closely mimic pancreatic ductal adenocarcinoma (PDAC) and techniques for tissue sampling of AIP are suboptimal. These limitations often result in delayed or failed diagnosis, which negatively impact patient management and outcomes. This study aimed to create an endoscopic ultrasound (EUS)-based convolutional neural network (CNN) model trained to differentiate AIP from PDAC, chronic pancreatitis (CP) and normal pancreas (NP), with sufficient performance to analyse EUS video in real time. Design A database of still image and video data obtained from EUS examinations of cases of AIP, PDAC, CP and NP was used to develop a CNN. Occlusion heatmap analysis was used to identify sonographic features the CNN valued when differentiating AIP from PDAC. Results From 583 patients (146 AIP, 292 PDAC, 72 CP and 73 NP), a total of 1 174 461 unique EUS images were extracted. For video data, the CNN processed 955 EUS frames per second and was: 99% sensitive, 98% specific for distinguishing AIP from NP; 94% sensitive, 71% specific for distinguishing AIP from CP; 90% sensitive, 93% specific for distinguishing AIP from PDAC; and 90% sensitive, 85% specific for distinguishing AIP from all studied conditions (ie, PDAC, CP and NP). Conclusion The developed EUS-CNN model accurately differentiated AIP from PDAC and benign pancreatic conditions, thereby offering the capability of earlier and more accurate diagnosis. Use of this model offers the potential for more timely and appropriate patient care and improved outcome.

Abstract Background Endoscopic intervention for pancreatic fluid collections (PFCs) with disconnected pancreatic duct syndrome (DPDS) has been associated with failures and increased need for additional endoscopic and non-endoscopic interventions. The primary aim of this study was to determine the outcomes of endoscopic ultrasound (EUS)-guided transmural drainage of PFCs in patients with DPDS. Methods In patients undergoing EUS-guided drainage of PFCs from January 2013 to January 2018, demographic profiles, procedural indications and details, adverse events, outcomes, and subsequent interventions were retrospectively collected. Overall treatment success was determined by PFC resolution on follow-up imaging or stent removal without recurrence. Results EUS-guided drainage of PFCs was performed in 141 patients. DPDS was present in 57 of them (40 %) and walled-off necrosis was the most frequent type of PFC (55 %). DPDS was not associated with lower clinical success, increased number of repeat interventions, or increased time to PFC resolution. Patients with DPDS were more likely to be treated with permanent transmural plastic double-pigtail stents (odds ratio [OR] 6.4; 95 % confidence interval [CI] 2.5 – 16.5; P < 0.001). However, when stents were removed, DPDS was associated with increased PFC recurrence after stent removal (OR 8.0; 95 %CI 1.2 – 381.8; P = 0.04). Conclusions DPDS frequently occurs in patients with PFCs but does not negatively impact successful resolution. DPDS is associated with increased PFC recurrence after stent removal.

INTRODUCTION: Exogenous transmission of infection via duodenoscope cross-contamination after failed disinfection is a preventable risk. Inadequate reprocessing of reusable duodenoscopes can occur. Given this possibility, a new single-use duodenoscope was recently developed. It had comparable performance to reusable duodenoscopes when tested by expert endoscopists in a comparative bench model for endoscopic retrograde cholangiopancreatography (ERCP). We subsequently aimed to assess the performance of this disposable duodenoscope in a series of human cases. METHODS: Six academic medical centers enrolled consecutive adults 18 years or older without altered pancreaticobiliary anatomy scheduled for an ERCP. Seven ERCP experts rated the new EXALT single-use Model D duodenoscope (Boston Scientific, Marlborough, MA; ClinicalTrials.gov NCT03701958) in ERCP procedures for Overall Satisfaction on a scale of 1 (unsatisfied) to 10 (very satisfied), “Not preferred/Neutral/Preferred” compared to reusable duodenoscopes on 23 ERCP maneuvers, and Qualitative Comparison of 17 performance characteristics on a scale of 1 (not preferred) to 5 (comparable to reusable duodenoscopes). RESULTS: Sixty consecutive patients had an ERCP using the first-generation single-use duodenoscope in April and May 2019. Thirty-seven (61.7%) were male, mean age was 64.4 years, and 44 (73.3%) had a prior ERCP at baseline. All 60 ERCP procedures were successfully performed, 58 (96.7%) with the single-use duodenoscope alone and 2 (3.3%) with crossover to a reusable duodenoscope. Median overall satisfaction with the single-use duodenoscope was rated 9.0 (range 1-10). The overall satisfaction rating was ≥ 7 in 56 (93.3%) ERCPs. All three ratings were at or above midpoint (Overall satisfaction ≥ 5, Comparative ERCP maneuver “Neutral/Preferred,” Qualitative Comparative rating of performance characteristic 3-5) in 47 (78.3%) cases. Four ERCPs had low (≤4) overall satisfaction ratings attributed to inadequate pushability of instruments due to suboptimal positioning of the duodenoscope in front of the papilla; these ERCPs were a subset in which biliary or pancreatic duct strictures were dilated and/or stented. CONCLUSION: Expert endoscopists reported good overall performance of a new single-use duodenoscope in a broad array of cases. Low ratings occurred rarely and were associated with particular ERCP maneuvers. Detailed design improvements to the single-use duodenoscope are underway.

OBJECTIVES: Expression of prostaglandin biosynthetic pathway enzymes in mucinous pancreatic cysts is unknown. Cyclooxygenase-2 (COX-2) inhibition is a potential cancer chemoprevention strategy for these lesions. We evaluated the expression of COX-2, cytosolic phospholipase A2 (cPLA2), and protein kinase B (AKT) in the epithelium of pancreatic cysts and correlated enzyme expression with aspirin (ASA) use and cyst fluid prostaglandin E 2 (PGE 2 ) concentration. METHODS: Pathology of 80 resected pancreatic cysts was reviewed. Expression of COX-2, cPLA2, and AKT was quantified by tissue immunohistochemistry immunoreactivity scores (IRSs). IRS values were compared between cyst types and (in 30 cases) with matched cyst fluid PGE 2 concentrations. RESULTS: The mean IRS was higher in the epithelium of mucinous vs nonmucinous cysts for COX-2 (6.1 ± 4.7 vs 3.2 ± 2.8, P = 0.01) and cPLA2 (6.9 ± 3.0 vs 2.9 ± 2.9, P < 0.001). Cyst epithelial COX-2 expression was higher in mucinous cysts with low-grade dysplasia vs those with high-grade dysplasia or invasive carcinoma (IRS 8.0 ± 3.9 vs 1.5 ± 2.9, P < 0.001), whereas the opposite was found for cPLA2 (6.2 ± 3.0 vs 8.6 ± 2.3, P = 0.005). Cyst fluid PGE 2 concentrations did not correlate with either the IRS or a history of low- to moderate-dose ASA use. CONCLUSIONS: COX-2 and cPLA2 are overexpressed in the epithelium of mucinous pancreatic cysts. COX-2 and/or cPLA2 inhibition might prevent the emergence or progression of mucinous pancreatic cysts, but higher doses of ASA or nonsteroidal anti-inflammatory drugs may be necessary to substantially inhibit cyst epithelial COX-2 activity.

BACKGROUND: There is lack of consensus on post-operative surveillance for resected non-invasive intraductal papillary neoplasms (IPMNs). In this study we explored risk factors for subsequent PC in patients with MD-IPMN undergoing partial pancreatectomy. METHODS: We searched the Mayo Clinic surgical pathology database for all cases of resected MD-IPMN between 1997 and 2014. Cases with histologically confirmed main pancreatic duct involvement either isolated or in a mixed pattern with branch-duct involvement were included. Outcomes of PC in the remnant pancreas, and death related to MD-IPMN were assessed with survival analyses (Kaplan–Meier and Cox regression). RESULTS: Among the 179 patients with resected MD-IPMN the incidence of concomitant PC and high-grade dysplasia (HGD) in the resected specimen was 23 and 14%, respectively. The mean duration of follow-up was 4.31 years (range 0.12–13.5 years). Excluding 28 subjects who either underwent initial total pancreatectomy or partial pancreatectomy with surgical margins positive for PC/HGD, the 5-year incidence of subsequent PC was 12%, including 60.6% and 15.6% in those with initial PC and HGD, respectively. The 10-year incidence of PC was 21.2% overall, 60.6% for PC, 38.3% for HGD, and 3.0% for LGD. Risk of subsequent PC was significantly higher for those with initial PC compared with HGD (HR = 4.95, 95% CI: 1.63–15.03, p = 0.005 and for HGD compared with LGD (HR = 11.30, 95% CI: 1.55–82.26, p = 0.017). CONCLUSIONS: Patients with MD-IPMN with PC or HGD undergoing segmental pancreatectomy are at higher risk of subsequent PC and may benefit from post-operative surveillance. The post-operative surveillance intervals in resected MD-IPMNs need to be tailored based on dysplasia grade.

Objective Idiopathic duct-centric chronic pancreatitis (IDCP), also known as type 2 autoimmune pancreatitis (AIP), is an uncommon subtype of AIP. International Consensus Diagnostic Criteria for IDCP propose that the diagnosis requires pancreatic histology and/or concurrent IBD. We examined our experience with IDCP (type 2 AIP) to assess the appropriateness of these criteria, and identify unique characteristics in patients presenting with acute pancreatitis. Design We reviewed the Mayo Clinic AIP database through May 2014 to identify subjects with either definitive (n=31) or probable (n=12) IDCP. We compared demographic and clinical factors based on strength of diagnostic confidence (definitive versus probable), presence of IBD, and acute pancreatitis as the presenting manifestation. Relapse-free survival was determined using the Kaplan-Meier method. Results The clinical profiles were similar irrespective of the diagnostic criteria fulfilled. Common clinical presentations included acute pancreatitis (n=25, 58.1%, 12 of whom (27.9%) had recurrent pancreatitis) and pancreatic mass/obstructive jaundice (n=15, 34.9%). The cumulative relapse rate was 10.6% at 3 years (median follow-up 2.9 years). Relapse-free survival was similar for the different diagnostic categories, but was decreased in those initially presenting with acute pancreatitis (p=0.047) or treated with steroids (vs surgery, p=0.049). Conclusions The current diagnostic classification of probable IDCP and the inclusion of IBD as a supportive criterion appear valid, because patients have similar clinical profiles and disease-related outcomes to those with definitive IDCP. Concurrent IBD, especially in young patients, may suggest when IDCP is the underlying cause of recurrent acute pancreatitis, but additional studies are needed for validation.

Background. The SpyGlass Direct Visualization System (Boston Scientific, Natick, MA) is routinely used during single operator choledochoscopy (SOC) to identify biliary lesions or strictures with a diagnostic accuracy up to 88%. The objective of this study was to determine the interobserver agreement (IOA) of modified scoring criteria for diagnosing biliary lesions/strictures. Methods. 27 SPY SOC video clips were reviewed and scored by 9 interventional endoscopists based on published criteria that included the presence and severity of surface structure, vasculature visualization, lesions, and findings. Results. Overall IOA was “slight” for all variables. The K statistics are as follows: surface (K=0.12, SE = 0.02); vessels (K=0.14, SE = 0.02); lesions (K=0.11, SE = 0.02); findings (K=0.08, SE = 0.03); and final diagnosis (K=0.08, SE = 0.02). The IOA for “findings” and “final diagnosis” was also only “slight.” The final diagnosis was malignant (11), benign (11), and indeterminate (5). Conclusion. IOA using the modified criteria of SOC images was slight to almost poor. The average accuracy was less than 50%. These findings reaffirm that imaging criteria for benign and malignant biliary pathology need to be formally established and validated.