What is biliary drainage?

Biliary Drainage: Definition, Types, and Clinical Applications

Biliary drainage is a medical procedure that involves the decompression of an obstructed biliary system to relieve cholestasis and remove infected bile, which is essential for treating conditions like acute cholangitis and biliary obstruction. 1

Definition and Purpose

• Biliary drainage is a radical method to relieve cholestasis by creating a pathway for bile to flow from an obstructed biliary system, which is central to the treatment of acute cholangitis and other biliary obstructive conditions 2
• The procedure aims to decompress the biliary system, drain infected bile, and potentially remove obstructing elements such as stones 1
• Biliary drainage is critical in preventing or treating the pathological effects of biliary obstruction, including depressed immunity, impaired phagocytic activity, endotoxemia, septicemia, and renal failure 3

Types of Biliary Drainage

1. Endoscopic Biliary Drainage

• Endoscopic Retrograde Cholangiopancreatography (ERCP) with stent placement is the first-line procedure for biliary decompression 1
• ERCP is considered the safest and most effective method compared to percutaneous or surgical approaches, with lower risk of adverse events and less invasiveness 1
• Endoscopic drainage options include:
  • Endoscopic nasobiliary drainage (ENBD): Placement of a catheter through the nose into the bile duct 1, 2
  • Biliary stent placement: Insertion of a stent to maintain bile flow 1, 2
  • Endoscopic sphincterotomy (EST): Cutting of the sphincter of Oddi to facilitate bile flow and stone removal 1

2. Percutaneous Transhepatic Biliary Drainage (PTBD)

• PTBD is a second-line procedure reserved for patients in whom ERCP fails or is contraindicated 1
• The procedure involves inserting a catheter through the liver directly into the bile ducts under ultrasound or fluoroscopic guidance 4, 5
• PTBD may initially require an external drain if the obstruction cannot be easily traversed, with later conversion to an internal/external drain once acute infection resolves 1
• Potential complications include biliary peritonitis, hemobilia, pneumothorax, hematoma, liver abscesses, and patient discomfort related to the catheter 1

3. EUS-Guided Biliary Drainage (EUS-BD)

• A newer alternative technique for biliary drainage when conventional ERCP fails 1
• First reported in 2001, EUS-BD is indicated in cases of failed ERCP, altered anatomy, tumor-occluding access to the biliary tree, or contraindications to percutaneous access 1
• Technical success rates of 91.5% and clinical success rates of 87% have been reported 6
• Despite promising results, experience and procedure-specific tools remain limited, making traditional endoscopic and percutaneous techniques more commonly used 1

4. Surgical Biliary Drainage

• Open surgical drainage is now rarely used due to the widespread availability of less invasive endoscopic and percutaneous techniques 1
• Should only be considered when endoscopic or percutaneous approaches are contraindicated or have failed 2
• Associated with higher morbidity and mortality compared to minimally invasive approaches 2, 3

Clinical Applications and Timing

• In severe acute cholangitis, emergent biliary drainage is essential for survival 1
• For moderate (grade 2) acute cholangitis, early decompression (within 24 hours of admission) has been shown to reduce 30-day mortality 1
• In mild (grade 1) acute cholangitis, patients can initially be observed on medical treatment with antibiotics 1
• For malignant biliary obstruction, biliary drainage is preferred over medical management of symptoms as it improves overall quality of life 1

Complications of Biliary Drainage

• ERCP-related complications include pancreatitis (3.5%, range 1.6%-15.7%), hemorrhage (1.3%), cholangitis (<1%), stent migration, stent occlusion, perforation, and bile duct injury 1
• PTBD complications include bleeding, septicemia, bile leakage (1-5%), catheter occlusion with cholangitis, intrahepatic abscesses, catheter dislodgment, and bile peritonitis 4
• EUS-BD adverse events occur in approximately 17.9% of cases, including bile leak (4.1%), stent migration (3.9%), and infection (3.8%) 6

Important Considerations

• Injection of contrast under pressure during PTBD should be avoided as it may lead to cholangio-venous reflux and exacerbate septicemia 1
• For patients with gallbladder stones and acute cholangitis, cholecystectomy is recommended following resolution of acute cholangitis with medical treatment 2
• A collaborative approach involving surgeons, radiologists, and endoscopists is essential to achieve optimal outcomes in biliary drainage procedures 3