Acute pancreatic pseudocyst: incidence, risk factors, and clinical outcomes.

OBJECTIVES

The aim of this study was to analyze the incidence, risk factors, and clinical outcomes of pancreatic pseudocyst after acute or acute-on-chronic pancreatitis.

METHODS

We retrospectively reviewed the medical records of 350 patients with acute pancreatitis and 55 patients with acute-on-chronic pancreatitis.

RESULTS

Pancreatic pseudocyst developed in 14.6% of acute pancreatitis and in 41.8% of acute-on-chronic pancreatitis (P = 0.00). In the acute-on-chronic pancreatitis group, interval from symptom onset to hospital visit was longer, and the incidence of recurrent pancreatitis and alcoholic etiology was higher than that of the acute pancreatitis group (P < 0.01). There was no significant difference in the spontaneous resolution rate between both groups. Of the total 68 conservatively treated patients with pseudocyst, the pseudocyst decreased in size or disappeared in 77.9% and showed no change in 1.5%. The risk factors of pseudocyst were the presence of underlying chronic pancreatitis, the interval from symptom onset to visiting the hospital, and an alcoholic etiology. The factor-predicted spontaneous resolution was a single lesion.

CONCLUSIONS

Pseudocyst developed more frequently in patients with acute-on-chronic pancreatitis, and most pseudocysts improved spontaneously irrespective of underlying chronic pancreatitis. A longer period of a "wait-and-see" policy for more than 6 weeks is suggested for asymptomatic pseudocyst, especially for a single lesion.