A case of complicated emphysematous cholecystitis

Clinical History

A 59-year-old man presented with diffuse abdominal pain. His medical history was significant for hypertension, dyslipidaemia and type 2 diabetes complicated by peripheral neuropathy and severe vasculopathic disorders (retinopathy, previous left foot amputation and severe nephropathy). Laboratory tests revealed mild anaemia, increased neutrophilic count and inflammatory markers.

Imaging Findings

Abdominal X-ray examination revealed multiple dilated loops of small bowel and an oval finding with an air-fluid level inside and a thin peripheral rim of radiolucency into the right upper abdominal quadrant. US examination demonstrated a highly echogenic reflector with posterior acoustic shadowing in the gallbladder fossa and perihepatic fluid. CT images revealed a severe gallbladder distension with a large intraluminal air-fluid level and small gallstones. The gallbladder wall was thickened and filled with air. Post-contrast images did not show contrast enhancement of the gallbladder wall, suggestive for ischaemia. Pericholecystic fat-stranding and perihepatic fluid were present. Free air was identified in the right subdiaphragmatic space, at the hepatic hilum and into the right anterior subhepatic space, a finding indicative of pneumoperitoneum. Free fluid was present among small bowel loops, in the right paracolic gutter and Douglas pouch. These findings suggested a diagnosis of Emphysematous Cholecystitis complicated by gangrene and perforation.

Discussion

Emphysematous cholecystitis (EC) is a rare form of acute cholecystitis: both conditions have similar clinical manifestations but, due to its high mortality and morbidity, emphysematous cholecystitis requires urgent cholecystectomy [1].
Indeed our patient underwent urgent cholecystectomy. During surgery a diffuse peritonitis secondary to gallbladder perforation was found. At pathology specimen, the gallbladder was 12 cm in longitudinal diameter with thickened and fragmented walls; irregular, necrotic and gangrenous mucosa was found.
Emphysematous cholecystitis has a five times greater risk of perforation compared with uncomplicated acute cholecystitis [2].
EC is generally caused by infection of the gallbladder with clostridial organisms and occlusion of the cystic artery associated with atherosclerotic disease.
It is more common in patients with diabetes: diabetic microangiopathy and anatomical characteristics of cystic artery (end-artery with no collateral circulation) make this organ vulnerable to ischaemic sufferance.
Moreover, lack of pain sensitivity typical of diabetic patients could make symptoms mild and lead to a late diagnosis.
Abdominal X-ray is often not sensitive and specific enough; in few cases conventional radiography allows a direct demonstration of air in the gallbladder lumen and wall.

US appearance of gas may mimic that of a porcelain gallbladder or multiple stones in a contracted gallbladder [3].

CT is the most sensitive and specific imaging modality for identification of gas in the gallbladder lumen or wall. This important findings is due to a secondary infection of the gallbladder wall by gas-forming organisms such as Clostridium perfringens, Escherichia coli, and Bacilis fragilis.

In severe cases, acute EC may progress to gangrene and perforation.
Other nonspecific CT findings include pneumobilia, irregularity or discontinuity of the gallbladder wall, pericholecystic fluid, abscess formation, free intraperitoneal air secondary to perforation [4].

In high-risk or unsuitable surgical candidates, percutaneous cholecystostomy and antibiotic therapy may be used as temporizing measures until cholecystectomy is possible [5].

Differential Diagnosis List

Final Diagnosis

Emphysematous cholecystitis complicated by gangrene and perforation

URL:	https://www.eurorad.org/case/13654
DOI:	10.1594/EURORAD/CASE.13654
ISSN:	1563-4086