What is the Image-guided system (IGS)? IGS = A virtual 3-D model and mapping of the patient’s sinus anatomy + An interactive display of the surgeon’s instruments during surgery

The two parts work in tandem to help ENT surgeons navigate their instruments through the complex sinus passages without damaging healthy surrounding tissue.

How does the IGS work?

There are two separate stages to the system:

1. Pre-surgery creation of the 3-D anatomical model of the particular patient
2. During surgery, the interaction of the anatomical model and the tracking and display of the surgeon’s instruments

Pre-surgery stage

Prior to surgery:

• The patient undergoes a series of CT-scans that reveal the soft tissue and bony structures in and around the sinuses.
• A computer uses these scans to create a 3-D anatomical model of the anatomy of the patient’s sinuses.

In the Operating Theatre

1. Special “smart” instruments have been designed for ENT surgeons. These instruments are wireless with built–in LEDs and have a remote-control feature on each hand piece.
2. The surgeon uses the “smart instruments” to match the points on the 3-D model of the patient (which has been created prior to surgery).
3. The system’s software correlates the 3=D model with the actual position of the patient’s head to create a “digital map” of the patient’s face, including the contours.
4. The surgeon inserts the wireless “smart” instruments and an endoscope (a thin fibre-optic tube connected to a video camera) into the patient’s sinuses.
5. During surgery, monitors display:
1. The 3-D model of the patient’s sinus anatomy
2. A digital “map” of the patient’s face
6. The endoscopic display of the instruments moving throughout the sinuses.
7. The video camera attached to the endoscope follows the movement of the “smart” instruments.
8. The display shows real-time images of the “smart” instruments within the 3-D model and on the digital map of the face. The computer makes mathematically-calculated compensations for any patient movement.
9. Therefore, using the display, the surgeon can, at any time, pinpoint the exact location of the surgical instruments in the patient’s face.

What are the benefits of the IGS?

• The principal benefit is enhanced accuracy. There is a considerable amount of delicate anatomy within and around the sinuses, including the brain, the optic nerve and blood vessels.
• The IGS enables the surgeon (using the display) to make accurate movements in precise places.
• The IGS is particularly useful in difficult cases, such as revisionsurgery, where the patient’s internal anatomy may have been altered by previous operations.