Fatal necrotising emphysematous pancreatitis

A 63-year-old man with a medical history of hypertension, dyslipidemia and no prior surgeries, was admitted to the emergency department with severe epigastric pain radiating to the back and vomiting that started 6 hours before admission. Physical examination showed generalised abdominal tenderness, hypotension, tachycardia and tachypnea. Laboratory analysis revealed leucocytosis, elevated amylase, and metabolic acidosis with hyperlactatemia.

Due to the clinical severity of the patient, who was immediately transferred to the intensive care unit, abdominal and pelvic contrast-enhanced CT was performed early.

CT examination in portal phase showed a generalised decrease in normal pancreatic enhancement indicating glandular necrosis, with abundant intraparenchymal gas and in the root of the mesentery, suggesting necrotising emphysematous pancreatitis. There was free fluid in the peripancreatic and anterior pararenal spaces, without identifying organised collections. In addition, there were some subtle acute inflammatory changes in the adjacent colon. The portal and splenic veins were patent. No gallstones were identified, and Wirsung’s duct was not dilated.

Despite 24 hours of hydration and intensive supportive care, the patient persisted hemodynamically unstable and with hyperlactatemia, so CT examination was repeated early due to high suspicion of intestinal ischemia.

Second CT in arterial and portal phases did not show signs of mesenteric ischemia, but there was an increase of the intra-abdominal free fluid and the intraparenchymal and intra-abdominal gas, with pneumoperitoneum and almost complete destruction of the pancreatic parenchyma. Moreover, there were radiological signs of shock, like a generalised decrease in the arterial calibre and flattening of the inferior vena cava.

Acute pancreatitis is an inflammatory condition of the pancreatic gland, and it courses with an uncertain evolution. It is difficult to predict which patients will develop a clinically severe disease, and for this purpose, we can rely on the revised Atlanta 2012 classification [1].

The oedematous type is the most common (90-95%), and in most cases, it courses with an uncomplicated outcome. This type is characterised by a diffuse enlargement of the pancreatic gland as a consequence of an inflammatory oedema.

Approximately 5-10% of patients can develop pancreatic or peripancreatic necrosis, which is characterised by non-enhancing tissue on CT. The progression to infection of the necrotic tissue is uncommon and usually associated with refractory sepsis and multiorgan failure [2].

Emphysematous pancreatitis is a rare complication of severe acute necrotising pancreatitis. It’s developed by infection with gas-forming bacteria (E. Coli, C. Perfrigens, Klebsiella spp., Staphylococcus spp., etc), which leads to the presence of gas in the necrotic pancreatic parenchyma and in peripancreatic collections. Mortality is very elevated due to its rapid progression and association with septic shock.

Differential diagnosis includes other conditions in which gas is observed in the surrounding of the pancreas, like infected pseudocysts, abscesses, entero-pancreatic fistulae due to rupture of a pancreatic pseudocyst and tumours [3].

Contrast-enhanced CT is the most commonly used imaging technique for the diagnosis of acute pancreatitis due to its availability and short time of image acquisition, but contrast-enhanced MR imaging is also appropriate. Additionally, contrast-enhanced CT will help to detect further complications, decide if percutaneous drainage is feasible and guide a possible puncture. The pancreatic ultrasound examination has some limitations and requires an adequate acoustic window and collaboration of the patient, so its main role is to identify gallstones as a possible cause of pancreatitis [1,2].

The treatment of severe acute pancreatitis, including the emphysematous type, can be conservative, interventional, endoscopic or surgical. For conservative treatment, prompt supportive care involving a multidisciplinary team is mandatory. Some of the necrotic tissue can be removed and drained which will guide antibiotic treatment. Endoscopic transmural draining and necrosectomy are currently gaining popularity over surgery due to similar outcomes with associated shorter hospital stay, and lower costs [4,5].

Regardless of adequate treatment, mortality from emphysematous pancreatitis remains as high as 50% [6]. The patient reported in this case died after 36 hours of admission.

The radiologic diagnosis is paramount in the setting of acute pancreatitis in order to find the best treatment, and becomes even more important in severe cases like necrotising emphysematous pancreatitis because of its uncertain evolution.

All patient data have been completely anonymised throughout the entire manuscript and related files.