Role of early endoscopic ultrasound in idiopathic acute pancreatitis

BACKGROUND AND OBJECTIVES: The cause of acute pancreatitis (AP) remains elusive even after extensive work up in 10%–30 % of cases. It is important to determine the cause of AP as it helps for early treatment and limits unnecessary tests and to prevent recurrence which may improve a patient's long-term prognosis. Our study aimed to evaluate the diagnostic yield, feasibility, and management changes of early endoscopic ultrasound (EUS), performed within 24–48 h of admission in patients with idiopathic acute pancreatitis (IAP). METHODS: During the study period (2010–2016), 850 cases of AP were admitted. Out of these, etiology was determined in 666 (78.35%). There were 184 cases of IAP. EUS examination was done using a linear/radial echoendoscope. RESULTS: Out of 158 cases (90 males; age range: 15–70 years) of IAP (26 were excluded), EUS was able to clinch the diagnosis in 110 patients (69.6 %). The most common causes of IAP included biliary stone disease (gallbladder microlithiasis, common bile duct microlithasis/stone/sludge) (n = 60) followed by chronic pancreatitis (CP) (n = 25), pancreatic tumor (n = 11), and pancreaticobiliary ascariasis (n = 10). Other etiologies included hydatid cyst rupture of bile duct, opium addiction, and duplication cyst. No cause was found in 48 (31.4%) patients. CONCLUSIONS: Early EUS establishes diagnosis in about 70% cases of IAP and changes the short-term management in IAP. Biliary stone disease was the predominant cause for IAP followed by CP. EUS is a safe investigation with a high diagnostic yield. An early EUS can influence important therapeutic decisions and prevent further attacks of AP which may occur if a delayed EUS is performed and thus improve long term prognosis. An early EUS has an additional advantage of making an early diagnosis of pancreatic tumors/pancreaticobiliary ascariasis and ampullary/papillary stones which can be treated endoscopically. It also prevents making the wrong diagnosis of sludge as etiological factor for AP which may occur in patients undergoing a delayed EUS since sludge may be secondary to AP due to prolonged fasting, total parenteral nutrition or antibiotics such as ceftriaxone.