The technology of augmented and mixed reality (AR/MR) is useful in various areas of modern surgery. We considered the use of augmented and mixed reality technologies as a method of preoperative planning and intraoperative navigation in abdominal cancer patients. Practical use of AM/MR raises a range questions, which demand suitable solutions. The difficulties and obstacles we encountered in the practical use of AR/MR are presented, along with the ways we chose to overcome them. The most demonstrative case is covered in detail. The three-dimensional anatomical model obtained from the CT scan needed to be rigidly attached to the patient's body, and therefore an invasive approach was developed, using an orthopedic pin fixed to the pelvic bones. The pin is used both similarly to an X-ray contrast marker and as a marker for augmented reality. This solution made it possible, not only to visualize the anatomical structures of the patient and the border zone of the tumor, but also to change the position of the patient during the operation. In addition, a noninvasive (skin-based) marking method was developed that allows the application of mixed and augmented reality during operation. Both techniques were used (8 clinical cases) for preoperative planning and intraoperative navigation, which allowed surgeons to verify the radicality of the operation, to have visual control of all anatomical structures near the zone of interest, and to reduce the time of surgical intervention, thereby reducing the complication rate and improving the rehabilitation period.
Keywords: CT scan; Hololens; augmented reality; cancer; mixed reality; surgery.