Risk Factors Analysis and Nomogram Development for Pancreatic Pseudocyst in Idiopathic Chronic Pancreatitis

OBJECTIVE The study concerns identifying risk factors and developing nomogram for pancreatic pseudocyst (PPC) in idiopathic chronic pancreatitis (ICP) to facilitate early diagnosis. METHODS From January 2000 to December 2013, ICP patients admitted to our center were enrolled. Cumulative incidence of PPC was determined by Kaplan-Meier method. Patients were randomized into training group and validation group in a 2:1 ratio. Risk factors of PPC were determined through Cox proportional hazards regression model based on training cohort. The nomogram was constructed according to risk factors. RESULTS Totally, 1633 ICP patients were included with a median follow-up duration of 9.8 years. Pancreatic pseudocyst was observed in 14.7% (240/1633) of patients after ICP onset. The cumulative incidences of PPC were 8.2%, 10.4%, and 12.9% at 3, 5, and 10 years after ICP onset, respectively. Male sex, smoking history, history of severe acute pancreatitis, and chronic pain at/before diagnosis of ICP and complex pathologic changes in main pancreatic duct were recognized as risk factors of PPC development. The nomogram constructed with these risk factors achieved good concordance indexes. CONCLUSIONS Risk for PPC could be estimated through the nomogram. High-risk patients were suggested to be followed up closely to help early diagnosis of PPC.