Role of endoscopic ultrasonography in the diagnostic work-up of idiopathic acute pancreatitis (PICUS): study protocol for a nationwide prospective cohort study

Gallstones as a cause in presumed acute alcoholic pancreatitis: observational multicentre study

BACKGROUND

Data on the incidence and clinical relevance of gallstones in patients with suspected acute alcoholic pancreatitis are lacking and are essential to minimize the risk of recurrent acute pancreatitis. The aim of this study was to assess the incidence of gallstones and the associated rate of recurrent acute pancreatitis in patients with presumed acute alcoholic pancreatitis.

METHODS

Between 2008 and 2019, 23 hospitals prospectively enrolled patients with acute pancreatitis. Those diagnosed with their first episode of presumed acute alcoholic pancreatitis were included in this study. The term gallstones was used to describe the presence of cholelithiasis or biliary sludge found during imaging. The primary outcome was pancreatitis recurrence during 3 years of follow-up.

RESULTS

A total of 334 patients were eligible for inclusion, of whom 316 were included in the follow-up analysis. Gallstone evaluation, either during the index admission or during follow-up, was performed for 306 of 334 patients (91.6%). Gallstones were detected in 54 patients (17.6%), with a median time to detection of 6 (interquartile range 0-42) weeks. During follow-up, recurrent acute pancreatitis occurred in 121 of 316 patients (38.3%), with a significantly higher incidence rate for patients with gallstones compared with patients without gallstones (59% versus 34.2% respectively; P < 0.001), while more patients with gallstones had stopped drinking alcohol at the time of their first recurrence (41% versus 24% respectively; P = 0.020). Cholecystectomy was performed for 19 patients with gallstones (36%). The recurrence rate was lower for patients in the cholecystectomy group compared with patients who did receive inadequate treatment or no treatment (5/19 versus 19/34 respectively; P = 0.038).

CONCLUSION

Gallstones were found in almost one in every five patients diagnosed with acute alcoholic pancreatitis. Gallstones were associated with a higher rate of recurrent pancreatitis, while undergoing cholecystectomy was associated with a reduction in this rate.

Development of pancreatic diseases during long-term follow-up after acute pancreatitis: a post-hoc analysis of a prospective multicenter cohort

BACKGROUND AND AIM

More insight into the incidence of and factors associated with progression following a first episode of acute pancreatitis (AP) would offer opportunities for improvements in disease management and patient counseling.

METHODS

A long-term post hoc analysis of a prospective cohort of patients with AP (2008-2015) was performed. Primary endpoints were recurrent acute pancreatitis (RAP), chronic pancreatitis (CP), and pancreatic cancer. Cumulative incidence calculations and risk analyses were performed.

RESULTS

Overall, 1184 patients with a median follow-up of 9 years (IQR: 7-11) were included. RAP and CP occurred in 301 patients (25%) and 72 patients (6%), with the highest incidences observed for alcoholic pancreatitis (40% and 22%). Pancreatic cancer was diagnosed in 14 patients (1%). Predictive factors for RAP were alcoholic and idiopathic pancreatitis (OR 2.70, 95% CI 1.51-4.82 and OR 2.06, 95% CI 1.40-3.02), and no pancreatic interventions (OR 1.82, 95% CI 1.10-3.01). Non-biliary etiology (alcohol: OR 5.24, 95% CI 1.94-14.16, idiopathic: OR 4.57, 95% CI 2.05-10.16, and other: OR 2.97, 95% CI 1.11-7.94), RAP (OR 4.93, 95% CI 2.84-8.58), prior pancreatic interventions (OR 3.10, 95% CI 1.20-8.02), smoking (OR 2.33, 95% CI 1.14-4.78), and male sex (OR 2.06, 95% CI 1.05-4.05) were independently associated with CP.

CONCLUSION

Disease progression was observed in a quarter of pancreatitis patients. We identified several risk factors that may be helpful to devise personalized strategies with the intention to reduce the impact of disease progression in patients with AP.

Structured alcohol cessation support program versus current practice in acute alcoholic pancreatitis (PANDA): Study protocol for a multicentre cluster randomised controlled trial

BACKGROUND/OBJECTIVES

The most important risk factor for recurrent pancreatitis after an episode of acute alcoholic pancreatitis is continuation of alcohol use. Current guidelines do not recommend any specific treatment strategy regarding alcohol cessation. The PANDA trial investigates whether implementation of a structured alcohol cessation support program prevents pancreatitis recurrence after a first episode of acute alcoholic pancreatitis.

METHODS

PANDA is a nationwide cluster randomised superiority trial. Participating hospitals are randomised for the investigational management, consisting of a structured alcohol cessation support program, or current practice. Patients with a first episode of acute pancreatitis caused by harmful drinking (AUDIT score >7 and < 16 for men and >6 and < 14 for women) will be included. The primary endpoint is recurrence of acute pancreatitis. Secondary endpoints include cessation or reduction of alcohol use, other alcohol-related diseases, mortality, quality of life, quality-adjusted life years (QALYs) and costs. The follow-up period comprises one year after inclusion.

DISCUSSION

This is the first multicentre trial with a cluster randomised trial design to investigate whether a structured alcohol cessation support program reduces recurrent acute pancreatitis in patients after a first episode of acute alcoholic pancreatitis, as compared with current practice.

TRIAL REGISTRATION

Netherlands Trial Registry (NL8852). Prospectively registered.

Prospective multicentre study of indications for surgery in patients with idiopathic acute pancreatitis following endoscopic ultrasonography (PICUS)

BACKGROUND

Cholecystectomy in patients with idiopathic acute pancreatitis (IAP) is controversial. A randomized trial found cholecystectomy to reduce the recurrence rate of IAP but did not include preoperative endoscopic ultrasonography (EUS). As EUS is effective in detecting gallstone disease, cholecystectomy may be indicated only in patients with gallstone disease. This study aimed to determine the diagnostic value of EUS in patients with IAP, and the rate of recurrent pancreatitis in patients in whom EUS could not determine the aetiology (EUS-negative IAP).

METHODS

This prospective multicentre cohort study included patients with a first episode of IAP who underwent outpatient EUS. The primary outcome was detection of aetiology by EUS. Secondary outcomes included adverse events after EUS, recurrence of pancreatitis, and quality of life during 1-year follow-up.

RESULTS

After screening 957 consecutive patients with acute pancreatitis from 24 centres, 105 patients with IAP were included and underwent EUS. In 34 patients (32 per cent), EUS detected an aetiology: (micro)lithiasis and biliary sludge (23.8 per cent), chronic pancreatitis (6.7 per cent), and neoplasms (2.9 per cent); 2 of the latter patients underwent pancreatoduodenectomy. During 1-year follow-up, the pancreatitis recurrence rate was 17 per cent (12 of 71) among patients with EUS-negative IAP versus 6 per cent (2 of 34) among those with positive EUS. Recurrent pancreatitis was associated with poorer quality of life.

CONCLUSION

EUS detected an aetiology in a one-third of patients with a first episode of IAP, requiring mostly cholecystectomy or pancreatoduodenectomy. The role of cholecystectomy in patients with EUS-negative IAP remains uncertain and warrants further study.

Endoscopic Ultrasound to Identify the Actual Cause of Idiopathic Acute Pancreatitis: A Systematic Review

Idiopathic acute pancreatitis (IAP) presents a diagnostic challenge and refers to cases where the cause of acute pancreatitis remains uncertain despite a comprehensive diagnostic evaluation. Endoscopic ultrasound (EUS) has emerged as a valuable tool in the diagnostic workup of IAP. This review explores the pivotal role of EUS in detecting the actual cause of IAP and assessing its accuracy, timing, safety, and future technological improvement. In this review, we investigate the role of EUS in identifying the actual cause of IAP by examining the available literature. We aim to assess possible existing evidence regarding EUS accuracy, timing, and safety and explore potential trends of future technological improvements in EUS for diagnostic purposes. Following PRISMA guidelines, 60 pertinent studies were selected and analysed. EUS emerges as a crucial diagnostic tool, particularly when conventional imaging fails. It can offer intricate visualization of the pancreas, biliary system, and adjacent structures. Microlithiasis, biliary sludge, chronic pancreatitis, and small pancreatic tumors seem to be much more accurately identified with EUS in the setting of IAP. The optimal timing for EUS is post-resolution of the acute phase of the disease. With a low rate of complications, EUS poses minimal safety concerns. EUS-guided interventions, including fine-needle aspiration, collection drainage, and biopsies, aid in the cytological analysis. With high diagnostic accuracy, safety, and therapeutic potential, EUS is able to improve patient outcomes when managing IAP. Further refinement of EUS techniques and cost-effectiveness assessment of EUS-guided approaches need to be explored in multicentre prospective studies. This review underscores EUS as a transformative tool in unraveling IAP's enigma and advancing diagnostic and therapeutic strategies.

Consensus definition of sludge and microlithiasis as a possible cause of pancreatitis

OBJECTIVE

In up to 20% of patients, the aetiology of acute pancreatitis (AP) remains elusive and is thus called idiopathic. On more detailed review these cases can often be explained through biliary disease and are amenable to treatment. Findings range from biliary sludge to microlithiasis but their definitions remain fluid and controversial.

DESIGN

A systematic literature review (1682 reports, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines) analysed definitions of biliary sludge and microlithiasis, followed by an online international expert survey (30 endoscopic ultrasound/hepatobiliary and pancreatic experts; 36 items) which led to definitions of both. These were consented by Delphi voting and clinically evaluated in a retrospective cohort of patients with presumed biliary pancreatitis.

RESULTS

In 13% of original articles and 19.2% of reviews, microlithiasis and biliary sludge were used synonymously. In the survey, 41.7% of experts described the term 'sludge' and 'microlithiasis' as identical findings. As a consequence, three definitions were proposed, agreed on and confirmed by voting to distinctly discriminate between biliary sludge (hyperechoic material without acoustic shadowing) and microlithiasis (echorich calculi of ≤5 mm with acoustic shadowing) as opposed to larger biliary stones, both for location in gallbladder and bile ducts. In an initial attempt to investigate the clinical relevance in a retrospective analysis in 177 confirmed cases in our hospital, there was no difference in severity of AP if caused by sludge, microlithiasis or stones.

CONCLUSION

We propose a consensus definition for the localisation, ultrasound morphology and diameter of biliary sludge and microlithiasis as distinct entities. Interestingly, severity of biliary AP was not dependent on the size of concrements warranting prospective randomised studies which treatment options are adequate to prevent recurrence.

Machine learning-based decision tool for selecting patients with idiopathic acute pancreatitis for endosonography to exclude a biliary aetiology

BACKGROUND

Biliary microlithiasis/sludge is detected in approximately 30% of patients with idiopathic acute pancreatitis (IAP). As recurrent biliary pancreatitis can be prevented, the underlying aetiology of IAP should be established.

AIM

To develop a machine learning (ML) based decision tool for the use of endosonography (EUS) in pancreatitis patients to detect sludge and microlithiasis.

METHODS

We retrospectively used routinely recorded clinical and laboratory parameters of 218 consecutive patients with confirmed AP admitted to our tertiary care hospital between 2015 and 2020. Patients who did not receive EUS as part of the diagnostic work-up and whose pancreatitis episode could be adequately explained by other causes than biliary sludge and microlithiasis were excluded. We trained supervised ML classifiers using H2O.ai automatically selecting the best suitable predictor model to predict microlithiasis/sludge. The predictor model was further validated in two independent retrospective cohorts from two tertiary care centers (117 patients).

RESULTS

Twenty-eight categorized patients' variables recorded at admission were identified to compute the predictor model with an accuracy of 0.84 [95% confidence interval (CI): 0.791-0.9185], positive predictive value of 0.84, and negative predictive value of 0.80 in the identification cohort (218 patients). In the validation cohort, the robustness of the prediction model was confirmed with an accuracy of 0.76 (95%CI: 0.673-0.8347), positive predictive value of 0.76, and negative predictive value of 0.78 (117 patients).

CONCLUSION

We present a robust and validated ML-based predictor model consisting of routinely recorded parameters at admission that can predict biliary sludge and microlithiasis as the cause of AP.

Simple risk score to predict the likelihood of a positive EUS in idiopathic acute pancreatitis

BACKGROUND AND AIMS

We sought to derive a risk score, DORM65, of known variables to predict the likelihood of a positive EUS in patients with idiopathic acute pancreatitis (IAP).

METHODS

A retrospective cohort study of 180 patients with IAP was performed across 3 tertiary care centers between January 2018 and December 2021. Multivariate logistic regression modeling was performed to predict a positive EUS. Accuracy of the models was assessed by the area under the receiver-operating characteristic curve (AUROCC).

RESULTS

The diagnostic yield of EUS was 58.9% (95% confidence interval [CI], 51.7-66.1). The DORM65 scores of 5 predictors present before EUS with the best discrimination were a delayed EUS (defined as ≥82 days from the last episode of AP), obesity, not having had a repeated transabdominal US, male sex, and age ≥65 years at the time of EUS. For those at the lowest risk score group, the positive EUS rate was 13.0% compared with 100% in those at the highest risk group (relative risk, 7.67; P < .001). A score of 3 or more had a positive predictive value of 86.0% with a sensitivity of 34.9% and specificity of 91.9%. The model had a high predictive accuracy (AUROCC, .774; 95% CI, .707-.841). Adding 3 additional predictors (no cholecystectomy, no MRCP, and a single episode of AP) did not increase the accuracy significantly (AUROCC, .805; 95% CI, .742-.867).

CONCLUSIONS

DORM65 is easily calculated and accurately predicts a positive EUS in patients with IAP. Further validation is needed.

Exploring the Optimal Timing of Endoscopic Ultrasound Performance Post-Acute Idiopathic Pancreatitis

Background: Patients with acute idiopathic pancreatitis (AIP) should undergo further imaging tests such as endoscopic ultrasound (EUS) for further investigation. The time interval between an episode of AIP and EUS performance is still controversial. Aims: We aimed to explore the optimal timing for performing EUS and to reveal parameters that might predict longer intervals needed for performing EUS. Methods: We performed a single-center retrospective study at Galilee Medical Center from January 2015 to January 2020, at which point we included all patients who underwent EUS for further investigation of AIP. Results: Overall, we included 50 patients. The average age of all patients was 54.2 ± 17.6 years (range 22–69 years), and more than half of the study cohort were males (58%). Classifying patients as inflamed vs. normal pancreatic tissue on EUS, we found that among patients with normal pancreatic tissue, EUS was performed 44.7 ± 28.3 days from discharge, while for patients with inflamed pancreatic tissue, it was 48.1 ± 22.3 days (p = 0.37) after discharge. Notably, the CT severity index was significantly associated with inflamed pancreatic tissue on EUS, as it was 2.4 ± 0.74 vs. 1.5 ± 1.3 in the normal pancreatic tissue group (p = 0.03). There were no differences in the Bedside index for severity in acute pancreatitis (BISAP) scores, and there were no differences in the average American Society of Anesthesiologist Physical Status (ASA) scores between the two groups. Notably, 26.3% of patients had inflamed pancreatic tissue when performing EUS at 4 weeks, as compared to 16% who had inflamed pancreatic tissue at EUS performed after 6 weeks. Conclusion: Radiological severity score was the only important factor in determining the time interval of performing EUS after an episode of AIP. Intervals greater than six weeks seem to be needed among patients with higher Balthazar scores.

Early Prediction of Acute Biliary Pancreatitis Using Clinical and Abdominal CT Features

Background Assessment of the biliary origin of acute pancreatitis (AP) is crucial because it affects patient treatment to avoid recurrence. Although CT is systematically performed to determine severity in AP, its usefulness in assessing AP biliary origin has not been evaluated. Purpose To assess abdominal CT features associated with acute biliary pancreatitis (ABP) and to evaluate the predictive value of a combination of CT and clinical data for determining a biliary origin in a first episode of AP. Materials and Methods From December 2014 to May 2019, all consecutive patients who presented with a first episode of AP and with at least 6 months of follow-up were retrospectively reviewed. Evidence of gallstones was mandatory for a clinical diagnosis of ABP. Abdominal CT images were reviewed by two abdominal radiologists. Univariable and multivariable statistical analyses were performed, and a nomogram was constructed on the basis of the combination of clinical and CT features. This nomogram was validated in a further independent internal cohort of patients. Results A total of 271 patients (mean age ± standard deviation, 56 years ± 20; 160 men) were evaluated. Of these, 170 (63%) had ABP. At multivariable analysis, age (odds ratio [OR], 1.06; 95% CI: 1.03, 1.09; P < .001), alanine aminotransferase level (OR, 1.00; 95% CI: 1.00, 1.01; P = .009), gallbladder gallstone (OR, 15.59; 95% CI: 4.61, 68.62; P < .001), choledochal ring sign (OR, 5.73; 95% CI: 2.11, 17.05; P < .001), liver spontaneous attenuation (OR, 1.07; 95% CI: 1.04, 1.11; P < .001), and duodenal thickening (OR, 0.17; 95% CI: 0.03, 0.61; P = .01) were independently associated with ABP. The matching nomogram combining both clinical and CT features displayed an area under the curve of 0.94 (95% CI: 0.91, 0.97) in the study sample (n = 271) and 0.91 (95% CI: 0.84, 0.99) in the validation cohort (n = 51). Conclusion Abdominal CT provided useful features for diagnosis of acute biliary pancreatitis (ABP). Combining CT and clinical features in a nomogram showed good diagnostic performance for early diagnosis of ABP. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Chang in this issue.

[Imaging diagnostics in acute pancreatitis]

Abdominal imaging is an important component of the diagnostics of acute pancreatitis. In addition to the clinical features and the laboratory constellation, it serves to establish the diagnosis or the exclusion of other diseases and also the identification and assessment of the course of local complications and vascular changes that can arise during the course of acute pancreatitis. Due to the numerous imaging examination methods that are available, their combination options and the different examination times, there are diverse application options that have to be taken into account, such as the severity and duration of the disease, concomitant diseases and complications of acute pancreatitis. A rational use of imaging is an important prerequisite for high quality and at the same time cost-effective patient care. This review summarizes the current importance of imaging in acute pancreatitis, with particular reference to the updated S3 guidelines on acute pancreatitis.