Influence of the etiology of pancreatitis on the natural history of pancreatic pseudocysts.

We reviewed our experience with 90 patients with pancreatic pseudocysts to determine if the cause of pancreatitis influenced the patients' outcome. Acute pancreatitis (AP) occurred in 57 (63%) patients due to alcoholic (n = 15), postoperative (n = 14), biliary (n = 12), and other etiologies (n = 16). Thirty-three (37%) patients had chronic pancreatitis (CP) secondary to alcohol use (n = 27) or other causes (n = 6). Multiple pseudocysts were significantly more frequent in patients with acute alcoholic pancreatitis than in patients with chronic pancreatitis (47% versus 19%, p < 0.05). Spontaneous resolution occurred within 8 weeks in 10 (11%) patients with pseudocysts (AP = 9%, CP = 15%, p = NS). However, no patient with pseudocyst associated with biliary or postoperative pancreatitis underwent spontaneous resolution. Although pseudocysts associated with chronic pancreatitis were smaller in size (8.0 +/- 4.7 versus 5.7 +/- 3.8 cm, p < 0.05), a similar proportion of them required operation compared with AP pseudocysts (56% versus 58%). There were significantly more deaths in patients with postoperative pancreatitis compared with all other groups (29% versus 7%, p < 0.05). The outcome of pseudocysts was similar regardless of size (greater than 6 cm versus less than 6 cm) and presentation (acute versus delayed). Thus, the etiology of pancreatitis was a more important determinant of pseudocyst outcome than pseudocyst size or presentation.