ICG Based Fluorescence Imaging

What is ICG Fluorescence Imaging?

Indocyanine Green (ICG) Fluorescence Imaging is an advanced intraoperative optical technology that utilizes a specialized fluorophore called Indocyanine Green (ICG) combined with near-infrared (NIR) imaging camera systems designed to detect it.

How Does It Work?

The underlying principle can be compared to clinical “night-vision goggles”:

• Dye Administration: Prior to or during the surgical procedure, the patient is administered the ICG dye intravenously or via direct intratumoral/intratissue injection.
• Excitation Light Source: The specialized surgical camera system emits a near-infrared (NIR) excitation light onto the targeted operative field.
• Fluorescent Tissue Illumination: The ICG molecules absorb this light and re-emit energy in the form of a bright, fluorescent neon-green glow. Tissues that appear homogeneous under standard white-light illumination become distinctly demarcated on the screen, mapping out critical structures for the surgeon.

Primary Clinical Indications

This technology significantly minimizes the risk of accidental iatrogenic injury by visualizing critical structures hidden from the naked eye:

• Perfusion Assessment (Tissue Viability): In gastrointestinal, colorectal, or plastic reconstructive surgeries, it evaluates the microvascular blood supply of the tissue margins before performing an anastomosis (suturing). If the tissue margin fails to fluoresce green, it indicates hypoperfusion (inadequate blood supply), alerting the surgeon to alter the resection margins to prevent subsequent anastomotic leaks.
• Sentinel Lymph Node (SLN) Mapping: In oncological surgeries, it is utilized to trace the lymphatic drainage pathways from a primary tumor to locate the first draining lymph nodes (sentinel lymph nodes). This allows for highly targeted node dissection and staging.
• Visualization of the Biliary Tree: During cholecystectomy (gallbladder removal), anatomical variations can lead to accidental transection of the common bile duct. ICG illuminates the biliary anatomy, providing a clear visual safeguard to protect these critical ducts.
• Oncological Resections (Liver and Kidney): It delineates the exact tumor-to-parenchyma boundary in solid organ malignancies, enabling the surgeon to perform highly precise parenchyma-sparing organ resections.

Comparative Structural Matrix