Objective:

To study the outcome of acute collections occurring in patients with acute pancreatitis

Background:

There are limited data on natural history of acute collections arising after acute pancreatitis (AP).

Methods:

Consecutive patients of AP admitted between July 2011 and December 2012 were evaluated by imaging for development of acute collections as defined by revised Atlanta classification. Imaging was repeated at 1 and 3 months. Spontaneous resolution, evolution, and need for intervention were assessed.

Results:

Of the 189 patients, 151 patients (79.9%) had acute collections with severe disease and delayed hospitalization being predictors of acute collections. Thirty-six patients had acute interstitial edematous pancreatitis, 8 of whom developed acute peripancreatic fluid collections, of which 1 evolved into pseudocyst. Among the 153 patients with acute necrotizing pancreatitis, 143 (93.4%) developed acute necrotic collection (ANC). Twenty-three of 143 ANC patients died, 21 had resolved collections, whereas 84 developed walled-off necrosis (WON), with necrosis> 30%(P= 0.010) and Computed Tomographic Severity Index score≥ 7 (P= 0.048) predicting development of WON. Of the 84 patients with WON, 8 expired, 53 patients required an intervention, and 23 were managed conservatively. Independent predictors of any intervention among all patients were Computed Tomographic Severity Index score≥ 7 (P< 0.001) and interval between onset of pain to hospitalization> 7 days (P= 0.04).

Conclusions:

Patients with severe AP and delayed hospitalization more often develop acute collections. Pancreatic pseudocysts are a rarity in acute interstitial pancreatitis. A majority of patients with necrotising pancreatitis will develop ANC, more than half of whom will develop WON. Delay in hospitalization and higher baseline necrosis score predict need for intervention.