What is an Endoscopic Retrograde Cholangiopancreatography (ERCP) used to assess?

What ERCP is Used to Assess

ERCP is primarily used to assess the biliary and pancreatic ductal systems by visualizing their anatomy and pathology through fluoroscopic imaging after contrast injection, though it has evolved from a diagnostic tool to a predominantly therapeutic procedure. 1, 2

Primary Diagnostic Capabilities

ERCP visualizes the following anatomical structures and pathologies:

Biliary System Assessment

• Intrahepatic and extrahepatic bile ducts, including the common hepatic duct, common bile duct (CBD), and cystic duct 3
• CBD stones (choledocholithiasis) with very high sensitivity for detecting biliary ductal calculi 1
• Biliary strictures from both benign and malignant causes, with the ability to differentiate between pancreatic malignancies (46% sensitivity on brush cytology) and biliary malignancies (68% sensitivity) 1
• Biliary obstruction patterns, including filling defects representing stones, strictures with upstream ductal dilatation, and abrupt cutoffs suggesting malignant obstruction 3

Pancreatic System Assessment

• Pancreatic duct anatomy and integrity, particularly useful in evaluating suspected pancreatic duct injury or disruption 4
• Solid pancreatic neoplasms with sensitivity ranging from 57.1% (for pancreatic body/tail) to 82.4% (for pancreatic head lesions) when combined with FNA 1
• Ampullary carcinoma with superior sensitivity compared to other imaging modalities 1
• Pancreatic duct stones and chronic pancreatitis changes 5, 6

Specialized Conditions

• Primary sclerosing cholangitis, showing multifocal strictures with characteristic "beaded" appearance and "pruned tree" pattern in chronic stages 3
• Bile leaks following surgery or trauma, including biliovenous fistulas 4
• Pancreas divisum in patients with recurrent acute pancreatitis 6

Important Clinical Context

The role of ERCP has fundamentally shifted from diagnostic to therapeutic due to advances in non-invasive imaging like MRCP, which now serves as the preferred diagnostic modality. 1, 2, 3

When ERCP Should Be Used for Assessment

• High suspicion for CBD stones or malignant obstruction where immediate therapeutic intervention is anticipated 1
• Failed or equivocal non-invasive imaging (CT or MRI) in patients with suspected malignant biliary obstruction 1
• Tissue diagnosis needed through endoscopically directed brushing or FNA when combined with EUS 1
• Evaluation of biliary strictures in sclerosing cholangitis, though this should be done cautiously due to risk of inducing suppurative cholangitis 1

Critical Safety Considerations

The procedure carries significant risks that must be weighed against diagnostic benefits:

• 4-5.2% risk of major complications including pancreatitis, cholangitis, hemorrhage, and perforation 1, 2, 3
• 0.4% mortality risk 1, 2, 3
• Up to 10% morbidity when therapeutic sphincterotomy is performed 1

Technical Limitations

• Altered surgical anatomy (gastroenteric anastomoses) makes ERCP technically difficult, requiring alternative approaches like EUS-guided access or enteroscopy-assisted techniques 1, 5, 7
• Does not provide staging information for operability of pancreaticobiliary malignancies, unlike cross-sectional imaging 1
• Limited field of view compared to CT or MRI for detecting vascular encasement and metastatic disease 1

Practical Algorithm for ERCP Use

For suspected biliary obstruction with dilated CBD on ultrasound:

• If high clinical suspicion for CBD stones or need for immediate intervention → proceed directly to ERCP 1
• If lower suspicion or stable patient → obtain MRCP first to guide need for therapeutic ERCP 1

For jaundice without CBD dilatation on ultrasound:

• Consider additional laboratory testing and alternative diagnoses before ERCP 1
• MRCP may reveal pathology not visible on ultrasound 1

For trauma patients:

• Use ERCP selectively for suspected pancreatic or bile duct injury when CT is equivocal and patient is stable 4
• Particularly useful for persistent bile leaks or unexplained abdominal pain with elevated amylase 4