Necrotizing pancreatitis

Necrotizing
pancreatitis: peripancreatic necrosis alone. Acute necrotic collections (ANCs), affecting retroperitoneal spaces: left anterior pararenal space and lower extension until iliac fossa, affecting left paracolic gutter, posterior pararenal space and left psoas muscle.
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Necrotizing pancreatitis (NP) represents a severe form of acute pancreatitis. It is considered a subtype of acute pancreatitis as necrosis usually tends to occur 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.

Epidemiology

Around 5-10% of patients with interstitial edematous pancreatitis (i.e. uncomplicated acute pancreatitis) will develop necrosis .

Pathology

Necrotizing pancreatitis may become infected in up to 40% cases , more commonly after the first week.

Radiographic features

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 .

CT

Areas of necrosis are seen as non-enhancing low attenuating regions within the pancreas best 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 (see: emphysematous pancreatitis).

Treatment and prognosis

The presence of necrosis implies a poorer prognosis with mortality rates reported up to 14% , 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 .

Practical points