Endoscopic Ultrasound for Routine Assessment in Idiopathic Acute Pancreatitis

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.

ACUTE PANCREATITIS in HELSINKI in 2016-2018: INCIDENCE, ETIOLOGY and RISK FACTORS - analysis of 1378 acute pancreatitis episodes in a Finnish normal population

OBJECTIVES

Updated population-based studies on acute pancreatitis (AP) in Finland are lacking. Our aim was to evaluate the current data for AP in Helsinki.

MATERIALS AND METHODS

We performed an electronic health care records (EHRs) search on AP patients treated at Helsinki University Hospital between the years 2016 - 2018. Incidence was calculated, etiological and potential risk factors, as well as severity of AP were documented and analyzed.

RESULTS

Between 2016 and 2018 we found 1378 AP episodes on 1084 patients, 35% of the patients had several AP episodes, i.e., recurrent AP (RAP). The domicile-adjusted incidence was 42.2/100 000. 47% of the patients had alcohol etiology (59% men, 27% women) and 23% had biliary etiology, 21% were idiopathic and 2.9% were post-ERCP pancreatitis. 13.1% of the patients had passed at the end of September 2021. 45% of the patients were currently smoking, 11% were ex-smokers, and the highest percentage of smokers was in the group of alcohol-caused AP with 74% ever-smokers. Biliary AP had the highest amount of overweight patients. 24% of the patients used anticoagulation (AC) medication, and the percentage was significantly higher with idiopathic AP (48%). RAP, female sex and normal BMI associated with a mild form of AP.

CONCLUSIONS

Incidence of AP and the percentage of alcohol etiology are lower than earlier reported for Finland although still higher than in other Nordic countries. Smoking and the use of AC medication associate with AP.

Evaluating the role of endoscopic ultrasound in pancreatitis

INTRODUCTION

Endoscopic ultrasound (EUS) provides high-resolution images of both pancreatic parenchyma and duct and therefore is an integral component of evaluating and treating patients with pancreatitis and its complications. The development of enhanced EUS imaging techniques and newer EUS-specific accessories has expanded the diagnostic and therapeutic role of EUS in patients with acute and chronic pancreatitis (CP).

AREAS COVERED

This review discusses the current diagnostic and therapeutic role of EUS in acute pancreatitis (AP), CP, and autoimmune pancreatitis (AIP).

EXPERT OPINION

EUS plays a vital role in patients with AP by confirming the presence of common bile duct (CBD) stones in patients with acute biliary pancreatitis and intermediate probability of CBD stones. It plays an important role in the etiological evaluation of patients with idiopathic acute and recurrent pancreatitis. EUS is also an essential modality for diagnosing and managing pancreatico-biliary as well as gastroduodenal complications associated with CP. EUS-guided FNB using newer generation core biopsy needles has made possible accurate diagnosis of AIP by providing tissue samples with preserved architecture.

[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.

Utility of endoscopic ultrasound in idiopathic acute recurrent pancreatitis

Idiopathic acute recurrent pancreatitis (IARP) is defined as at least two episodes of acute pancreatitis with the complete or near-complete resolution of symptoms and signs of pancreatitis between episodes, without an identified cause. There is a paucity of information about the usefulness of endoscopic ultrasound (EUS) in IARP.

Factors predicting the severity of acute pancreatitis in elderly patients

BACKGROUND

Moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP) are associated with organ failure (OF), which can be lethal.

AIMS

This study determined the factors that predict the severity of AP at admission in elderly patients.

METHODS

In this retrospective study, the data from elderly patients (> 60 years of age) admitted within 72 h of onset of symptoms without OF were collected. These data at admission were analyzed and correlated with the severity of AP. To identify the factors associated with more serious AP (i.e. MSAP and SAP), patients were divided into mild acute pancreatitis (MAP) and MSAP + SAP groups.

RESULTS

A total of 198 patients [MAP group (n = 135) and MSAP + SAP group (n = 63)] were included. Biliary disease was the most common etiology. Respiratory failure was the most common OF. Logistic regression analyses indicated that idiopathic etiology (odds ratio [OR]: 3.029, 95% confidence interval [CI]: 1.017-9.022, p = 0.047), pre-existing pulmonary disease (OR: 7.104, CI 1.750-28.84, p = 0.006), increased hematocrit level (OR: 3.717, 95%CI 1.372-10.070, p = 0.010), serum calcium (OR: 0.023, 95%CI 0.001-0.371, p = 0.008), serum glucose (OR: 1.157, 95%CI 1.031-1.299, p = 0.013), arterial partial pressure of oxygen (PaO₂) (OR: 0.914, 95%CI 0.874-0.956, p < 0.001), and pleural effusion (OR: 4.979, 95%CI 1.863-13.303, p = 0.001) were independent predictors of more serious AP.

CONCLUSION

This study found that idiopathic etiology, pre-existing pulmonary diseases, increased hematocrit level or pleural effusion, higher serum glucose, and lower serum calcium or PaO₂ at the time of admission independently correlated with more serious AP in the elderly patients.

Endoscopic ultrasonography can detect a cause in the majority of patients with idiopathic acute pancreatitis: a systematic review and meta-analysis

BACKGROUND

Idiopathic acute pancreatitis (IAP) has a 25 % pancreatitis recurrence rate. Endoscopic ultrasonography (EUS) may diagnose treatable causes of IAP and hence prevent recurrence. The goal of this systematic review with meta-analysis is to determine the diagnostic yield of EUS and its impact on recurrence.

METHODS

PubMed, EMBASE and the Cochrane Library were systematically searched for English studies on EUS in adults with IAP. The primary outcome was diagnostic yield. Secondary outcomes included recurrence. Methodological quality was assessed using the QUADAS-2 score. Meta-analysis was performed to calculate the pooled diagnostic yield and risk ratio with 95 % confidence intervals (CI) using a random-effects model with inverse variance method.

RESULTS

22 studies were included, with 1490 IAP patients who underwent EUS. Overall diagnostic yield was 59 % (874 /1490; 95 %CI 52 % - 66 %). The most common etiologies were biliary (429 /1490; 30 %, 95 %CI 21 % - 41 %) and chronic pancreatitis (271 /1490; 12 %, 95 %CI 8 % - 19 %). In 2 % of patients, neoplasms were detected (45 /1490; 95 %CI 1 % - 4 %). There was no difference in yield between patients with or without recurrent IAP before EUS (risk ratio 0.89, 95 %CI 0.71 - 1.11).

CONCLUSIONS

EUS is able to identify a potential etiology in the majority of patients with IAP, detecting mostly biliary origin or chronic pancreatitis, but also neoplasms in 2 % of patients. EUS may be associated with a reduction of recurrence rate. Future studies should include complete diagnostic work-up and preferably include patients with a first episode of IAP only.

Acute pancreatitis

Acute pancreatitis is an unpredictable and potentially lethal disease. The prognosis mainly depends on the development of organ failure and secondary infection of pancreatic or peripancreatic necrosis. In the past 10 years, treatment of acute pancreatitis has moved towards a multidisciplinary, tailored, and minimally invasive approach. Despite improvements in treatment and critical care, severe acute pancreatitis is still associated with high mortality rates. In this Seminar, we outline the latest evidence on diagnostic and therapeutic strategies for acute pancreatitis.

The diagnostic work-up and outcomes of 'presumed' idiopathic acute pancreatitis: A post-hoc analysis of a multicentre observational cohort

INTRODUCTION

After standard diagnostic work-up, the aetiology of acute pancreatitis remains unknown in 16-27% of cases, a condition referred to as idiopathic acute pancreatitis (IAP). Determining the aetiology of pancreatitis is essential, as it may direct treatment in the acute phase and guides interventions to prevent recurrent pancreatitis.

METHODS

Between 2008 and 2015, patients with acute pancreatitis were registered prospectively in 19 Dutch hospitals. Patients who had a negative initial diagnostic work-up with regard to the underlying aetiology of their pancreatitis were labelled 'presumed' IAP. The aim of this study was to assess the use of diagnostic modalities and their yield to establish an aetiology in 'presumed' IAP, and to assess recurrence rates both with and without treatment.

RESULTS

Out of the 1632 registered patients, 191 patients had a first episode of 'presumed' IAP, of whom 176 (92%) underwent additional diagnostic testing: CT (n = 124, diagnostic yield 8%), EUS (n = 62, yield 35%), MRI/MRCP (n = 56, yield 33%), repeat ultrasound (n = 97, yield 21%), IgG4 (n = 54, yield 9%) and ERCP (n = 15, yield 47%). In 64 of 176 patients (36%) an aetiological diagnosis was established, mostly biliary (n = 39). In 13 out of 176 of patients (7%) a neoplasm was diagnosed. If additional diagnostic workup revealed an aetiology, the recurrence rate was lower in the treated patients than in the patients without a definite aetiology (15% versus 43%, p = 0.014).

CONCLUSION

Additional diagnostic testing revealed an aetiology in one-third of 'presumed' IAP patients. The aetiology found was mostly biliary, but occasionally neoplasms were found. Identification of an aetiology with subsequent treatment reduced the rate of recurrence.