Natural course of asymptomatic pancreatic walled off necroses

INTRODUCTION: Walled-off necrosis (WON) may develop in the long-term follow-up after acute pancreatitis due to acute inflammation of the pancreas. The aim of this study is to determine the course of asymptomatic patients who developed WON after acute pancreatitis during long-term follow-up MATERIALS AND METHODS: Among 1173 patients followed up with the diagnosis of acute pancreatitis between June 2016 and December 2019, 46 (3.9%) patients who developed WON during follow-up were evaluated retrospectively. Those who were symptomatic at the time of diagnosis or during follow-up were determined. Demographic characteristics, etiology, severity, localization and amount of necrosis (%) of the patients were determined. The date of diagnosis of walled-off necrosis and basal findings at the time of diagnosis (number of lesions, size, location, wall thickness, pancreatic duct rupture, if any) were recorded. The findings of those who underwent endoscopic/percutaneous/surgical intervention were recorded. RESULTS: Of the 46 patients who developed WON, 4 were excluded because of insufficient follow-up findings, 9 because drainage was performed at the time of diagnosis, and 2 patients died without even drainage. In the mean follow-up of 31 patients for 25.20±17.40 months, interventional intervention was required in 10 patients (32.3%) (within a mean of 122.5±152.5 days) (Group 1), and 21 patients (67.7%) were followed-up without any intervention. (Group 2). 6 patients were taken for drainage due to compression symptoms and 3 patients with suspected infected WON. Embolization was performed in one patient due to a splenic artery aneurysm detected in WON, but drainage was not performed. Drainage was applied endoscopically in 5 patients, percutaneously in 3 patients, and surgically in 1 patient. Biliary etiology was significantly more prominent in Group 1 (90.0% vs 47.6%, p<0.050). Intra-WON necrosis rate (68.50±28.50 vs 38.10±26.90%, p<0.05) and initial WON size (125.90±46.60 vs 89.30) in patients requiring drainage at follow-up ±45.00 mm, p<0.05) was found to be significantly higher. CONCLUSION: Patients with asymptomatic WON should be managed conservatively with close and regular follow-up. The obtained findings should be confirmed in larger longitudinal studies. Keywords: Acute necrotic collection, endoscopic drainage, necrotizing pancreatitis, walled-off necrosis.