ICG fluorescence imaging in laparoscopy: how it works

How ICG fluorescence imaging works

ICG is a dye that binds to plasma proteins, is administered according to the clinical protocol and is excited by light in the near-infrared range. It then emits light at a slightly longer wavelength. A NIR-capable camera captures this emission and the system displays it on the monitor, either as an overlay on the white-light image or as a separate high-contrast image.

The wavelengths matter for equipment selection. On the Richard Wolf System green platform, the documented ICG absorption range is 600–900 nm and the emission range is 800–850 nm. Ask any supplier for the equivalent figures and for evidence that their light source and sensor are matched to them.

Clinical uses: perfusion, cholangiography and lymph nodes

The main laparoscopic uses of NIR fluorescence are assessment of bowel and organ perfusion, for example before an anastomosis, fluorescence cholangiography to visualise the biliary structures and sentinel lymph node mapping. System green lists exactly these three applications: intraoperative assessment of visceral perfusion, fluorescence cholangiography and sentinel lymph node mapping.

Surgeons choose whether and how to use fluorescence for each case, with doses and timing following the local protocol and the dye's labelling. Hospitals should not market fluorescence as a guarantee of any clinical outcome; they should evaluate its role in their own practice.

• Perfusion assessment of bowel and other organs.
• Fluorescence cholangiography of the biliary tree.
• Sentinel lymph node mapping in suitable procedures.

Equipment needed for NIR fluorescence

A fluorescence tower needs a light source that delivers both white and NIR light, a camera with a dedicated NIR sensor, telescopes with good NIR transmission and a monitor that can show the overlay modes. Using standard components will not give a proper fluorescence image.

System green is built on the ENDOCAM Logic 4K platform and adds real-time ICG/NIR to standard endoscopy. It includes a laser-free ENDOLIGHT LEDgreen light source with automatic NIR/white light regulation, the Logic camera head green with a dedicated NIR sensor and PANOVIEW ULTRA telescopes optimised for ICG/NIR. It is compatible with core nova. The LED light source life is stated as up to 15,000 h. Read our model guide on Richard Wolf System green and the System green product page.

Imaging modes and workflow

System green offers three modes: white light, greenICG (fluorescence overlaid on the white-light image) and greenICG pure, a high-contrast grayscale view. The mode that suits a task depends on the surgeon's preference, so train staff to switch quickly and record both views where documentation matters.

Plan the theatre workflow with anaesthesia and nursing: who prepares and gives the dye, how lights are dimmed if needed, and how the camera is set up before the first incision. Because it uses a 4K camera platform, also review the requirements in our article on 4K versus Full HD laparoscopy.

Procurement questions and next steps

Ask suppliers which wavelengths the system covers, whether the source is laser or LED, how fluorescence and white light are balanced, what telescopes are required and how the system integrates with your tower. Confirm the registration status of the system and of the dye in the UAE with the relevant authority.

Beckfinity can provide information on Richard Wolf fluorescence solutions. See the Richard Wolf brand page or contact us via the contact page for a consultation.