Pancreatic pseudocysts: prognostic factors for their development and their spontaneous resolution in the setting of acute pancreatitis.

BACKGROUND AND AIM: Previous studies on the development of pancreatic pseudocysts following acute pancreatitis were monocentric, mostly retrospective, did not fulfil the Atlanta criteria, and featured a mixture of patients with post-acute and chronic pancreatitis. Therefore, the natural course of pancreatic pseudocysts after acute pancreatitis and the reasons for their spontaneous resolution remain unknown.
METHODS: This prospective study of 369 patients investigated the prognostic factors for development of pancreatic pseudocysts and for their spontaneous resolution after a first episode of acute pancreatitis.
RESULTS: On discharge, 124 (34%) patients still had pancreatic fluid collections. The prognostic factor for these fluid collections was severe acute pancreatitis. Follow-up examination 3 and 6 months later showed pancreatic pseudocysts in 36 (10%) patients (30 with and 6 without prior fluid collection), and in 27 (7%) patients (25 with and 2 without pancreatic pseudocyst after 3 months), respectively. The prognostic factors for their development were alcohol abuse and an initial severe course of the disease. Spontaneous complete resolution of the pancreatic pseudocysts occurred in 11 (31%) of the 36 patients. Prognostic factors for the spontaneous resolution were no or mild symptoms (nausea, vomiting, abdominal pain) and a maximal cyst diameter of <4 cm.
CONCLUSIONS: Patients with a first severe attack of acute pancreatitis and fluid collections at discharge should be checked by ultrasonography for pancreatic pseudocysts 3 months later. In patients with a small pseudocyst and mild symptoms therapy may be postponed for a further 3 months, since spontaneous resolution is possible.