Can an intraoperative cholangiogram (IOC) be performed after an Endoscopic Retrograde Cholangiopancreatography (ERCP)?

Intraoperative Cholangiogram After ERCP: Feasibility and Considerations

Yes, intraoperative cholangiogram (IOC) can be performed after an ERCP, but it may not be necessary in many cases due to the high diagnostic accuracy of ERCP and the potential for redundancy.

Rationale for IOC After ERCP

Indications for IOC After ERCP

• When there is clinical suspicion of residual stones despite prior ERCP
• When anatomical clarification is needed during surgery
• When the biliary anatomy was not fully visualized during ERCP

Evidence-Based Considerations

The 2019 WSES guidelines indicate that IOC remains a valuable diagnostic tool even after ERCP has been performed 1. The guidelines state that IOC has a pooled sensitivity of 0.87 and a specificity of 0.99, making it a reliable method for detecting common bile duct stones that might have been missed or developed after ERCP 1.

Clinical Decision Algorithm

Step 1: Assess the Completeness of Prior ERCP

• Was the ERCP technically successful with complete visualization of the biliary tree?
• Were all suspected stones removed during ERCP?
• Was a sphincterotomy performed during ERCP?

Step 2: Evaluate Risk Factors for Residual Stones

• Multiple stones identified during ERCP
• Large stones (≥4.5mm) that may have been difficult to extract 2
• Abnormal liver function tests persisting after ERCP 3

Step 3: Consider Timing Between ERCP and Surgery

• If cholecystectomy is performed during the same admission as ERCP, the risk of recurrent pancreatitis is diminished, but same-admission cholecystectomy is still advised to prevent other biliary complications 1
• Small stones (<4.5mm) identified on IOC may pass spontaneously if given adequate time (approximately 11 days) 2

Effectiveness and Limitations

Effectiveness of IOC After ERCP

• IOC can detect anatomical variations that may not have been apparent during ERCP 1
• During exploratory laparotomy, when biliary injury is suspected but not identified, an intraoperative cholangiogram is strongly recommended 1

Limitations and Considerations

• Nearly one-third of patients with abnormal IOC have normal findings on subsequent ERCP, suggesting a high false-positive rate for IOC 4, 3
• The rate of stone extraction after positive IOC is low (approximately 25% of those who undergo ERCP after positive IOC, or 2% of all patients with positive IOC) 5
• ERCP carries significant risks including pancreatitis (4.6%), cholangitis (2.8%), hemorrhage (1.1%), and perforation (0.4%) 6

Special Considerations

Technical Aspects

• If a sphincterotomy was performed during ERCP, contrast during IOC may flow directly into the duodenum, potentially making interpretation more challenging
• IOC may be more difficult to interpret after ERCP due to residual contrast or edema

Alternative Approaches

• If there is uncertainty after ERCP, less invasive methods such as MRCP (sensitivity 93%, specificity 96%) or endoscopic ultrasound may be considered before proceeding to IOC 1, 6
• Laparoscopic ultrasound is an alternative with pooled sensitivity of 0.87 and specificity of 1.00 1

Conclusion

While IOC can be performed after ERCP, careful consideration should be given to whether it adds value based on the completeness of the prior ERCP, clinical suspicion of residual stones, and the potential for unnecessary additional procedures. The decision should be guided by clinical judgment and local expertise.