What is the standard procedure for an Endoscopic Retrograde Cholangiopancreatography (ERCP) procedure?

ERCP Procedure Overview

ERCP (Endoscopic Retrograde Cholangiopancreatography) is primarily a therapeutic endoscopic procedure for treating biliary and pancreatic disorders, involving advancement of a side-viewing endoscope through the mouth into the duodenum to access and intervene on the biliary and pancreatic ductal systems. 1

Primary Indications for ERCP

ERCP should be reserved for therapeutic interventions rather than purely diagnostic purposes, given its significant complication profile 1:

Biliary Indications

• Common bile duct stones with jaundice, dilated common bile duct, acute pancreatitis, or cholangitis - ERCP with endoscopic sphincterotomy (ES) and stone removal achieves clearance in 80-95% of cases 1, 2
• Biliary strictures requiring stenting - successful in >90% of distal CBD strictures 1
• Cholangitis requiring urgent biliary drainage 2
• Malignant biliary obstruction for palliation when surgery is not elected 3

Pancreatic Indications

• Severe biliary pancreatitis - early ERCP reduces morbidity and mortality compared to delayed intervention 3
• Recurrent pancreatitis or pancreatic pseudocysts in selected patients 3
• Type I sphincter of Oddi dysfunction - responds to endoscopic sphincterotomy 3

When ERCP Should NOT Be Performed

ERCP should be avoided for purely diagnostic purposes when non-invasive alternatives (MRCP or EUS) can provide equivalent information 1:

• Low probability of choledocholithiasis in patients undergoing cholecystectomy 3
• Suspected PSC or biliary stricture evaluation - MRCP should be the principal imaging modality 1
• Acute pancreatitis diagnosis (unless biliary pancreatitis with cholangitis is suspected) 3
• Women with recurrent pain, normal bilirubin, and no objective signs of biliary disease 3

Standard ERCP Procedure Components

Pre-Procedure Preparation

• Prophylactic antibiotics should be administered to reduce infection risk 2
• Procedure performed under sedation or general anesthesia 4
• Informed consent discussing 4-5.2% major complication rate and 0.4% mortality risk 1, 2

Technical Steps

1. Endoscope advancement - side-viewing duodenoscope passed through mouth, esophagus, stomach into second portion of duodenum 5
2. Papilla identification and cannulation - selective cannulation of bile duct and/or pancreatic duct through major duodenal papilla 5
3. Contrast injection and fluoroscopic imaging - to visualize ductal anatomy 5
4. Therapeutic interventions as indicated:
   • Endoscopic sphincterotomy (ES) - cornerstone technique used in most therapeutic ERCPs 6
   • Stone extraction using balloon or basket retrieval devices 6
   • Stent placement for strictures or drainage 6
   • Tissue sampling via brush cytology or forceps biopsy 1

Tissue Sampling During ERCP

When biliary strictures require tissue diagnosis 1:

• Brush cytology - minimum of five passes required, specificity approaches 100% but sensitivity only 60-68% for biliary malignancies 1
• Forceps biopsy - minimum of three samples needed 1
• Combined approach increases diagnostic sensitivity to 60% 1

Complication Profile

Major complications occur in 4-5.2% of cases 1, 2:

• Pancreatitis: 3-5% (up to 10% with sphincterotomy) 1, 2
• Bleeding: 2% when combined with sphincterotomy 1
• Cholangitis: 1% 1
• Perforation: rare but serious 1
• Procedure-related mortality: 0.4% 1, 2

Risk Mitigation

Avoidance of unnecessary ERCP is the best way to reduce complications 3. Endoscopists should have appropriate training and expertise before performing advanced procedures 3.

Alternative Approaches When Standard ERCP Fails

ERCP failure occurs in 5-10% of cases due to 1:

• Gastric outlet or duodenal obstruction from tumor
• Altered anatomy from prior surgery or diverticula

Alternative drainage options 1:

• Percutaneous transhepatic cholangiography
• EUS-guided biliary drainage
• Overtube-assisted enteroscopy for altered anatomy 4

Role in Specific Clinical Scenarios

Pre-Cholecystectomy

• Not required if low probability of choledocholithiasis 3
• Indicated for high suspicion of CBD stones, visible stones on imaging, gallstone pancreatitis, or cholangitis 2

Malignancy

• Primary role is palliation of biliary obstruction 3
• No established role for preoperative biliary drainage in surgical candidates 3
• Best modality for diagnosing ampullary cancers 3

PSC Diagnosis

• Diagnostic ERCP should be reserved for highly selected cases with normal high-quality MRCP but high suspicion for PSC, when cytology is required, or when therapeutic intervention is anticipated 1