What is the role of Indocyanine Green (ICG) in cholecystectomy?

Role of Indocyanine Green (ICG) in Cholecystectomy

Indocyanine Green Fluorescence Cholangiography (ICG-C) is a promising non-invasive tool for visualizing biliary structures during laparoscopic cholecystectomy, but its routine use to reduce bile duct injury rates is not yet recommended by current guidelines. 1

Mechanism and Administration

ICG is taken up almost exclusively by hepatic parenchymal cells after intravenous injection and is secreted entirely into the bile, making it ideal for biliary visualization 2. When administered:

• Optimal dose: 0.1 mg intravenously 30 minutes before surgery 1
• Visibility: ICG becomes visible in the liver and bile ducts within 20 minutes after administration and remains visible for approximately 2 hours 3
• Alternative method: Direct gallbladder ICG injection can also be used, where bile is aspirated from the gallbladder, mixed with ICG solution, and reinjected to fluoresce the gallbladder, cystic duct, and common bile duct structures 4

Benefits of ICG in Cholecystectomy

1. Enhanced Visualization

   • Provides real-time, non-invasive imaging of extrahepatic biliary structures 1
   • Enables earlier visualization of the common bile duct and cystic duct compared to conventional imaging 3
   • Particularly valuable in difficult cases with inflammation, obesity, or anatomical variations 1

2. Operative Efficiency

   • Reduces operative time, especially in complex cases (approximately 20 minutes shorter compared to conventional white light) 5
   • Reported reduction from 117.9 minutes to 86.9 minutes in some studies 1

3. Safety Considerations

   • Helps prevent bile duct injuries by clearly delineating biliary anatomy before dissection 1
   • No significant adverse reactions reported with low-dose ICG administration 1
   • No radiation exposure compared to traditional intraoperative cholangiography 1

Current Evidence on Bile Duct Injury Prevention

• Bile duct injury occurs in approximately 0.4% of elective procedures and 0.8% of emergency procedures 1
• Recent systematic reviews suggest ICG-C shows a trend toward lower bile duct injury rates compared to conventional white light, though the difference has not reached statistical significance 5
• A survey of 3,411 experienced surgeons found that the use of adjuncts such as ICG-C was not significantly associated with a lower risk of bile duct injuries 1

Critical View of Safety Plus

The "Critical View of Safety Plus" concept combines traditional critical view of safety with ICG fluorescence:

• In one study, surgeons were more likely to proceed with cutting and division when using ICG (58% vs 44% with conventional imaging) 6
• Improved scores for cystic plate clearance (1.42 vs 1.28, p=0.018) and hepatocystic triangle clearance (1.4 vs 1.26, p=0.0334) 6

Limitations and Considerations

• Equipment availability: Requires a laparoscope with near-infrared imaging capability 4
• Timing of administration is crucial for optimal visualization 1
• Despite promising results, high-quality evidence supporting routine use is still limited 1
• The World Society of Emergency Surgery considers ICG-C promising but does not yet recommend routine use (Weak recommendation, low quality of evidence) 1

Clinical Algorithm for ICG Use in Cholecystectomy

1. Consider ICG use particularly in:

   • Cases with expected difficult anatomy (inflammation, obesity)
   • Patients with anatomical variations
   • Complex cases where operative time reduction would be beneficial

2. Administration protocol:

   • Administer 0.1 mg ICG intravenously 30 minutes before surgery
   • Alternative: Direct gallbladder injection technique if intravenous method is contraindicated

3. During procedure:

   • Use intermittent fluorescence imaging to identify biliary structures early
   • Establish the critical view of safety with both conventional and fluorescence imaging
   • Use ICG to confirm biliary anatomy before clipping and division

4. Safety caveat:

   • Despite ICG use, maintain standard safety protocols including proper dissection technique and establishment of critical view of safety

While ICG shows promise in improving visualization and potentially reducing operative time, surgeons should recognize that current guidelines do not yet support its routine use for bile duct injury prevention.