Necrotizing pancreatitis (NP) represents the severe form of pancreatitis. It is considered a subtype of acute pancreatitis as necrosis usually tends to occurs early, within the first 24-48 hours, but can also rarely occur with subacute forms.
A key feature is a significant amount of pancreatic and peripancreatic tissue necrosis associated with pancreatitis.
Around 5-10% of patients with interstitial edematous pancreatitis (i.e. uncomplicated acute pancreatitis) will develop necrosis 5.
Necrotizing pancreatitis can become infected, more commonly after the first week.
NP presents most often as necrosis affecting both the pancreas and peripancreatic tissues. Rarely it will affect only the peripancreatic tissues or pancreas in isolation 5.
Areas of necrosis are seen as non-enhancing low attenuating regions within the pancreas but observed if a dual phase pancreatic study is performed.
Foci of gas may also be present in more extreme cases; extraluminal gas is highly suggestive of superimposed infection.
Treatment and prognosis
The presence of necrosis implies a poorer prognosis with mortality rates reported up to 14% 3, if sterile. Mortality rates reach 20-30% in infected cases that are drained, either surgically or percutaneously, and about 100% in infected cases without drainage 5.
- gas is the hallmark of infection
- acute necrotic collection ( less than 4 weeks): sterile or infected
- walled-off necrosis (more than 4 weeks): sterile or infected