title: Features and choice of treatment of acute and chronic pancreatic pseudocysts--with special reference to invasive intervention.
abstract: OBJECTIVE
  It was the aim of this study to characterize the features of acute and chronic pancreatic pseudocysts (PPs) and to identify the factors predictive of the need for invasive treatment.
  
  
  METHODS
  Thirty-six patients with PPs treated at Nippon Medical School between January 1995 and December 2004 were studied retrospectively. The cases were divided into 4 groups based on 4 features: association with acute pancreatitis, association with chronic pancreatitis, spontaneous resolution, and persistent symptoms requiring therapeutic intervention. Group 1 included 9 patients with acute PPs which resolved spontaneously. Group 2 included 9 patients with acute PPs with persistent symptoms or associated complications requiring interventional treatment. Group 3 included 9 patients with chronic PPs which resolved spontaneously, and group 4 included 9 patients with chronic PPs with persistent symptoms or associated complications requiring interventional treatment.
  
  
  RESULTS
  Among the 36 patients, 13 were women and 23 were men. The etiologies were pancreatitis due to alcoholism in 18 cases (50.0%), biliary tract disease in 8 cases (22.2%) and other conditions in 10 cases (27.8%). The average duration of follow-up was 24.2 +/- 18.5 months. The patients in group 1 were significantly older than those in group 2 (67.6 +/- 16.1 vs. 40.6 +/- 14.1 years; p = 0.011). The mean size of the PPs was significantly larger in groups 1 and 4 than in group 3 (p < 0.05) and significantly larger in group 2 than in group 4 (p < 0.05). There were no significant differences between groups 1 and 2 in the size of the PPs or in the Ranson score of previous pancreatitis. The increase in size of the PPs during follow-up in each of the spontaneously resolved groups (groups 1 and 3) differed significantly from that in each of the interventional treatment groups (groups 2 and 4; p < 0.05). The main cause of the acute pancreatitis in group 1 was biliary tract disease, while that in group 2 was alcoholism (significantly different, p < 0.05). The number of patients with symptoms related to pseudocysts at the time of diagnosis was significantly higher in group 1 than in group 3.
  
  
  CONCLUSIONS
  Growth of the PPs during follow-up is the strongest predictor of the need for invasive treatment in both acute and chronic cases. Among acute PPs, the size of the pseudocyst is not in itself a predictor of invasive treatment. Invasive treatment may pose higher risks for pseudocysts with an etiology of alcoholic acute pancreatitis. However, the size of the pseudocyst may be a more important prognostic factor than an etiology of pancreatitis. and IAP.
authors.affiliation: Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Lu
authors.forename: Eiji
authors.initials: E
authors.lastname: Uchida
authors.forename: Shigeki
authors.initials: S
authors.lastname: Yokomuro
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Takayuki
authors.initials: T
authors.lastname: Aimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Tajiri
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004322:Drainage; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010192:Pancreatic Pseudocyst / Q000150:complications / Q000628:therapy*; D010195:Pancreatitis / Q000150:complications; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome