Post ERCP duodenal perforation

Clinical History

A 42-year-old lady with abdominal pain, gallstones and obstructive jaundice underwent an endoscopic retrograde cholangio-pancreatography (ERCP) and sphincterotomy for relief of her symptoms. The patient presented the following day with abdominal pain. A clinical and biochemical diagnosis of post ERCP pancreatitis and a CT abdo/pelvis was requested.

Imaging Findings

The CT examination reveals a tiny pocket of gas in the retroperitoneum (Fig. 1, 2) adjacent to the duodenum with secondary inflammatory changes around the pancreas. The patient was managed conservatively with a follow-up CT revealing resolution of the retroperitoneal gas and the inflammatory changes around the pancreas (Fig. 3).

Discussion

Background: Duodenal perforation following ERCP is a recognised complication with an incidence of 0.3% - 1.3% [1, 2, 3, 4]. Other complications include post-ERCP pancreatitis with 10% and bleeding/infection (cholangitis) with 1% each. Early identification and expeditious management of a perforation have been shown to reduce the associated morbidity and mortality.
Clinical Presentation: Duodenal perforation presents with abdominal or flank pain in 44%-100% of cases. The other symptoms include peritonitis, fever and tachycardia. Blood tests usually reveal leucocytosis and a raised amylase.
Three types of perforation complicating ERCP have been recognized [5, 6]
 Type I: Free bowel wall perforation
 Type II: Retroperitoneal duodenal perforation
 Type III: Perforation of the pancreatic or bile duct
Retroperitoneal duodenal perforations are the most common. CT is the most sensitive test for detecting perforation and the clinical or radiographic amount of air does not indicate either the size of the perforation or correlate with the severity of the complication, but reflects the degree of manipulation that occurred after the perforation [7, 8, 9].
Most injuries (76%-80%) are diagnosed during ERCP, some are picked up on routine post ERCP abdominal radiographs. Post-procedural diagnosis requires a high index of clinical suspicion. CT abdomen with oral contrast is indicated in cases presenting with persistent symptoms. Imaging findings include free gas detected either on plain radiographs or CT. However, retroperitoneal air can also be seen following sphincterotomy in asymptomatic patients, not requiring any intervention [8, 10].
The origin of retroperitoneal air is presumed to be related to dissection through an injured or macroscopically intact bowel, which has been described following colonoscopy, although sealed microperforations are also possible. So retroperitoneal air in the absence of symptoms should warrant careful observation but may not require any intervention. Distinction needs to be made between perforation, clinically insignificant retroperitoneal air, and pancreatitis, particularly since pancreatitis and perforation can have a similar clinical presentation or occur simultaneously. The diagnosis of retroperitoneal duodenal perforation associated with pancreatitis should be based upon the detection of retroperitoneal air or contrast in a symptomatic patient meeting criteria for post-ERCP pancreatitis.
Our patient was managed conservatively and had a successful recovery with resorption of both the gas and the peripancreatitic changes.

Differential Diagnosis List

Final Diagnosis

Type III duodenal perforation

URL:	https://www.eurorad.org/case/11498
DOI:	10.1594/EURORAD/CASE.11498
ISSN:	1563-4086