GI Studies
42 Surgical Cholangiography
Anatomy
- Liver (produces bile)
- Gallbladder (stores and releases bile)
- Cystic duct (connects gallbladder to common bile duct)
- Hepatic ducts (right and left) → join to form the common hepatic duct
- Common bile duct (CBD) → joins pancreatic duct, empties into duodenum
- Ampulla of Vater (hepatopancreatic ampulla) and Sphincter of Oddi (regulates bile flow)
- Duodenum (site of bile entry)
Indications, Contraindications, and Patient Preparation
Indications
- To evaluate biliary anatomy and function during or after gallbladder surgery
- To check for residual stones in the common bile duct after cholecystectomy
- To assess patency of bile ducts and sphincter of Oddi
- To investigate unexplained jaundice or biliary obstruction
Contraindications
- Allergy to iodinated contrast media
- Severe infection (e.g., cholangitis) may be a relative contraindication — radiologist will weigh risks
- Unstable surgical patients where prolonged imaging is unsafe
Patient Preparation
- No special prep if intraoperative (performed during surgery)
- If T-tube cholangiography (post-op), patient should be NPO for several hours before the exam
Procedure Types
Intraoperative Cholangiography
- Performed during gallbladder surgery (cholecystectomy)
- Contrast medium: Water-soluble iodinated contrast injected into cystic duct catheter
- Imaging: Fluoroscopy and spot images taken while surgeon manipulates ducts
- Purpose: Confirm ductal anatomy, rule out stones before completing surgery
Evaluation Criteria
- Entire biliary tree visualized (hepatic ducts → CBD → duodenum)
- No evidence of stones, strictures, or leakage
- Contrast flows freely into duodenum
Postoperative (T-tube) Cholangiography
- Performed several days after gallbladder removal
- A T-tube catheter remains in common bile duct for drainage
- Contrast medium: Water-soluble iodinated contrast injected through T-tube
- Imaging: Spot images obtained as contrast outlines biliary system
- Purpose: Detect retained stones, strictures, or leaks after surgery
Evaluation Criteria
- Complete filling of biliary ducts with contrast
- Visualization of contrast entering duodenum
- Absence of leaks or filling defects (stones)
Procedure Adaptation
- Patient position: Supine for imaging; surgical positioning if intraoperative
- Contrast injection: Must be done slowly to avoid duct rupture or reflux into pancreatic duct (risk of pancreatitis)
- Pediatrics: Lower volume of contrast; indications often congenital (e.g., biliary atresia)
- Post-op patients: May be tender; move slowly and explain procedure carefully
Exposure Factors & Technical Considerations
- SID: 40 inches
- kVp: 65–75 (lower kVp enhances contrast in biliary system, because we are using iodinated contrast)
- mAs: Short exposure times
- Contrast: Water-soluble iodinated contrast (NEVER barium)
- Imaging equipment: Fluoroscopy with spot or digital capture
- Collimation: Center over right upper quadrant; include liver, ducts, and proximal duodenum
- Shielding: Standard shielding where possible, though limited intraoperatively
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Hows & Whys of Surgical Cholangiography
Anatomy & Physiology
- Why is the sphincter of Oddi important in cholangiography?
It regulates bile flow into the duodenum and can be a site of obstruction. - Why might a patient still have stones after gallbladder removal?
Stones may remain in the common bile duct or hepatic ducts — surgical cholangiography detects these.
Contrast & Technique
- Why is iodinated contrast used instead of barium?
Because it is water-soluble, safe if leakage occurs, and provides rapid duct visualization. - Why must contrast be injected slowly?
Rapid injection may overdistend ducts or reflux into the pancreatic duct, increasing risk of pancreatitis.
Clinical Considerations
- Why is intraoperative cholangiography performed during gallbladder surgery?
To confirm ductal anatomy and ensure no stones remain before the surgery is completed. - Why is a T-tube used after gallbladder surgery?
It allows bile drainage, prevents obstruction during healing, and provides access for postoperative cholangiography. - What does a filling defect on cholangiogram indicate?
A possible stone, stricture, or mass within the biliary duct. - Why should the radiologist be careful to observe contrast reaching the duodenum?
It confirms patency of the bile ducts and sphincter of Oddi.