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.

Some patients develop acute inflammation of the pancreas without a clear cause. These patients have a high risk of developing more episodes of acute inflammation of the pancreas. Potentially, such inflammation could be caused by tiny gallstones that physicians are not able to detect. If this is true, these patients may also benefit from surgical removal of the gallbladder. However, this is still controversial. Endoscopic ultrasonography is a diagnostic procedure during which a physician looks at the gallbladder and bile ducts in detail via a small ultrasound probe inserted through the mouth. This endoscopic ultrasonography may be able to detect gallstones better than physicians were able to previously. This study tested the value of endoscopic ultrasonography, and the number of patients who developed more episodes of acute inflammation after endoscopic ultrasonography was recorded. Some 106 patients with acute inflammation of the pancreas for the first time without a clear cause participated and were offered endoscopic ultrasonography. The number of times endoscopic ultrasonography found a cause for the acute inflammation was recorded, as well as safety parameters, number of patients who developed more episodes of acute inflammation, and quality of life. After screening 957 patients, 105 ultimately underwent endoscopic ultrasonography. A cause was found in one-third of patients. This was mostly (tiny) gallstones, but chronic inflammation and even tumours were found. These patients were mostly treated surgically for their gallstones and tumours. In the first year after the first acute episode of inflammation, the inflammation came back at least once in almost one in six patients in whom endoscopic ultrasonography did not find a cause. This occurred less in patients in whom a cause was found; the inflammation came back in 1 in 16 of these patients. It was also found that having inflammation coming back negatively affected quality of life. In this study, endoscopic ultrasonography was able to detect a cause in one-third of patients with first-time acute inflammation of the pancreas. In one in four patients, this cause could be treated by a surgical procedure. Whether surgical removal of the gallbladder can be helpful in patients in whom endoscopic ultrasonography is not able to detect an aetiology should be investigated in further studies.

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

INTRODUCTION: Idiopathic acute pancreatitis (IAP) remains a dilemma for physicians as it is uncertain whether patients with IAP may actually have an occult aetiology. It is unclear to what extent additional diagnostic modalities such as endoscopic ultrasonography (EUS) are warranted after a first episode of IAP in order to uncover this aetiology. Failure to timely determine treatable aetiologies delays appropriate treatment and might subsequently cause recurrence of acute pancreatitis. Therefore, the aim of the Pancreatitis of Idiopathic origin: Clinical added value of endoscopic UltraSonography (PICUS) Study is to determine the value of routine EUS in determining the aetiology of pancreatitis in patients with a first episode of IAP. METHODS AND ANALYSIS: PICUS is designed as a multicentre prospective cohort study of 106 patients with a first episode of IAP after complete standard diagnostic work-up, in whom a diagnostic EUS will be performed. Standard diagnostic work-up will include a complete personal and family history, laboratory tests including serum alanine aminotransferase, calcium and triglyceride levels and imaging by transabdominal ultrasound, magnetic resonance imaging or magnetic resonance cholangiopancreaticography after clinical recovery from the acute pancreatitis episode. The primary outcome measure is detection of aetiology by EUS. Secondary outcome measures include pancreatitis recurrence rate, severity of recurrent pancreatitis, readmission, additional interventions, complications, length of hospital stay, quality of life, mortality and costs, during a follow-up period of 12 months. ETHICS AND DISSEMINATION: PICUS is conducted according to the Declaration of Helsinki and Guideline for Good Clinical Practice. Five medical ethics review committees assessed PICUS (Medical Ethics Review Committee of Academic Medical Center, University Medical Center Utrecht, Radboud University Medical Center, Erasmus Medical Center and Maastricht University Medical Center). The results will be submitted for publication in an international peer-reviewed journal. TRIAL REGISTRATION NUMBER: Netherlands Trial Registry (NL7066). Prospectively registered.