Table 3 A step-by-step WSES protocol for performing an effective ICG Fluorescent Cholangiography in the Emergency Setting
Step | Details |
|---|---|
1. Dilution of ICG | Preparation: Reconstitute a 25 mg vial of ICG with 10 mL of sterile water or normal saline to create a solution with a concentration of 2.5 mg/mL |
Mixing: Thoroughly mix the solution to achieve a consistent concentration. Protect it from light to prevent degradation | |
2. Dose of Administration | Recommended Dose: Administer ICG at 0.2 to 0.5 mg/kg body weight |
Standard Protocol: Typically, 10–25 mg of ICG is administered for an average adult, depending on the patient’s weight and surgical scenario. Cholecystitis and obesity are risk factors for deacresed fluorescence intensity imaging | |
3. Timing of Administration | Timing Before Surgery: Inject ICG intravenously ~ 45 min before imaging or surgery to allow absorption by the liver and excretion into bile ducts |
Emergency Adjustments: In emergencies, the time can be shortened to 30 min, potentially affecting fluorescence intensity | |
4. Injection Point | Intravenous Injection: Inject ICG intravenously, preferably through a central line or large peripheral vein, to ensure rapid distribution |
5. Time Acquisition of Images | Imaging Window: Start near-infrared (NIR) fluorescence imaging 45 min after ICG administration for optimal biliary tree visualization, not less than 20 min after the administration of ICG |
Real-Time Imaging: Perform intraoperative imaging in real-time to dynamically assess biliary anatomy during dissection | |
6.Interpretation | Qualitative Interpretation: |
- Visualization of Anatomy: Bright fluorescence should outline biliary structures (cystic duct, common bile duct, hepatic ducts) | |
- Anomalies: Absence or poor fluorescence may indicate biliary obstruction, inadequate timing and dose, or imaging equipment issues | |
Quantitative Interpretation: | |
- Fluorescence Intensity: Measure the intensity of fluorescence in bile ducts; lower intensity may indicate reduced liver function or incomplete excretion | |
- Flow Assessment: Dynamic imaging allows for bile flow assessment, with quantitative measures potentially correlating with obstruction severity |