What is it?

Near-infrared fluorescence (NIR) cholangiography using indocyanine green (ICG) is an advanced imaging technique used during hepato biliary and laparoscopic surgeries, especially laparoscopic cholecystectomy.
It involves intravenous or direct biliary administration of ICG, a fluorescent dye that binds plasma proteins and is excreted in bile. When illuminated with near-infrared light (around 750–810 nm), the dye emits fluorescence, enabling real-time visualization of the biliary tree without the need for X-ray or radiation.

Salient Features

  • Real-time, radiation-free imaging of biliary anatomy.
  • Non-invasive alternative to intraoperative cholangiography (IOC) using X-rays.
  • Enhances critical view of safety (CVS) during gallbladder dissection.
  • Useful in difficult cholecystectomy, variant biliary anatomy, or re-do surgery.
  • Safe dye with very low adverse reaction rate (<0.05%).

Types of ICG/NIR Cholangiography

  1. Intravenous ICG administration (most common)
    • Given preoperatively (45–120 min before dissection).
    • ICG is taken up by the liver and excreted into bile ducts, outlining biliary anatomy.
  2. Direct intrabiliary ICG injection
    • Injected into cystic duct, gallbladder, or via ERCP stent.
    • Provides more immediate and localized ductal visualization.
  3. Hybrid techniques
    • Combination of intravenous and direct instillation for enhanced clarity.

Implementations (Clinical Applications)

  • Laparoscopic cholecystectomy – To identify cystic duct, common bile duct (CBD), and avoid bile duct injury.
  • Difficult gallbladders – Severe inflammation, fibrosis, adhesions, or unclear anatomy.
  • Liver surgery – Segmental visualization of bile ducts during hepatic resection.
  • Biliary reconstruction / transplant – Identifying ductal openings and ensuring patency.

Effects and Benefits

  • Improved visualization of biliary anatomy compared to white-light dissection.
  • Reduced bile duct injuries (BDIs) – a major cause of morbidity and litigation.
  • Faster and simpler than IOC – no need for fluoroscopy or radiology team.
  • Cost-effective in the long term (fewer complications).
  • Safe in pregnancy (no ionizing radiation).

Rationale

  • Bile duct injury during cholecystectomy is a rare but devastating complication.
  • Traditional intraoperative cholangiography (IOC) uses X-ray fluoroscopy with contrast injection but requires extra time, radiation exposure, and equipment.
  • ICG-NIR fluorescence provides a radiation-free, real-time, user-friendly alternative that integrates into minimally invasive platforms (laparoscopy, robotic surgery).
  • It aligns with modern surgical safety principles like the “critical view of safety” (Strasberg).

✅ In short: NIR/ICG cholangiography is a safe, effective, and radiation-free imaging technique that enhances intraoperative biliary visualization, reduces complications, and supports precision in hepato biliary surgery.

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