What is the role of Indocyanine Green (ICG) in minimizing post-operative bleeding in hepatectomy?

Role of Indocyanine Green (ICG) in Minimizing Post-operative Bleeding in Hepatectomy

Indocyanine green (ICG) is a valuable tool for reducing post-operative bleeding in hepatectomy through improved visualization of vascular and biliary structures, enabling more precise resection and reducing blood loss compared to traditional techniques. 1, 2

ICG for Liver Function Assessment and Surgical Planning

• ICG retention test (ICG-R15) serves as a non-invasive predictor of portal hypertension and liver function, helping to determine the safe extent of liver resection and minimize bleeding risk 3
• Various ICG-R15 cutoffs guide decision-making for hepatectomy procedures in cirrhotic patients, limiting resection to patients with ICG-R15 below 20-25% and segmentectomy to those below 30-35% 3
• ICG clearance correlates with perioperative mortality and helps determine the maximum extent of resection according to Makuuchi criteria 3
• ICG kinetics, when combined with other liver function parameters (Child-Pugh, MELD, liver stiffness measurement), improves patient selection and reduces the risk of post-hepatectomy liver failure and associated bleeding complications 3, 4

ICG for Intraoperative Visualization and Bleeding Reduction

• ICG fluorescence imaging provides real-time visualization of hepatobiliary anatomy during surgery, allowing for more precise dissection and reduced risk of vascular injury 5, 6
• Meta-analysis evidence shows that ICG fluorescence imaging-guided hepatectomy significantly reduces:
  • Intraoperative blood loss (mean difference = 12.99; 95% CI = 12.00-13.97) 1
  • Operative time (mean difference = -55.45; 95% CI = -78.85 to -32.05) 1
  • Postoperative complications (rate difference = -0.07; 95% CI = -0.12 to -0.01) 1
• Another meta-analysis of laparoscopic hepatectomy found ICG guidance reduced intraoperative bleeding (WMD = -108.16,95% CI, -127.88 to -88.44, p = 0.000) compared to conventional approaches 2

Technical Aspects of ICG Use in Hepatectomy

• ICG can be administered intravenously for different purposes:
  • 2-5 days before surgery for tumor visualization 7
  • During surgery for real-time vascular mapping and anatomic segmentation 6
  • For evaluation of liver perfusion and detection of ischemic areas that might lead to bleeding 6
• ICG fluorescence has advantages over conventional imaging techniques:
  • Non-invasive and avoids radiation exposure 5
  • Provides enhanced visualization of vascular structures with laparoscopic magnification 7
  • Enables clear identification of tumor margins, reducing the risk of bleeding from inadequate resection margins 7, 6

Limitations and Considerations

• Tissue penetration with ICG is limited to 5-10mm, meaning deeper tissue cannot be visualized using this method 5
• ICG fluorescence imaging requires specialized equipment and monitors 6
• While ICG is useful for visualizing surface structures, it may not detect deeper vascular injuries that could lead to postoperative bleeding 5
• ICG should be considered an adjunct to, not a replacement for, standard surgical techniques for preventing bleeding 8

Practical Implementation

• For laparoscopic hepatectomy, ICG fluorescence imaging is particularly valuable as it:
  • Reduces operative time (WMD = -20.81,95% CI, -28.02 to -13.59, p = 0.000) 2
  • Shortens hospital stay (WMD = -1.23,95% CI, -1.50 to -0.95, p = 0.000) 2
  • Decreases postoperative complications (OR = 0.49,95% CI, 0.26-0.91, p = 0.025) 2
• ICG can be used for both positive staining (highlighting target segments/tumors) and negative staining (counterstaining normal liver tissue), allowing for more precise resection and reduced bleeding risk 6

ICG fluorescence imaging represents a significant advancement in hepatectomy procedures, offering surgeons enhanced visualization capabilities that directly translate to reduced blood loss and improved surgical outcomes.