AR

The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training.

The use of AR in robotic surgery is expanding rapidly, due to its ability to easily incorporate AR directly into the operators’ console, which allows the surgeon to navigate more quickly and better identify important structures. The CG projection can be displayed separately or as an overlay of real-time video as needed by the surgeon. A few authors successfully applied AR during a robotic surgery with satisfactory results, showing a possible role of AR as a future trend in robotic surgery
An augmented reality system provides the surgeon with computer-processed imaging data in real-time via dedicated hardware and software. The projection of AR is made possible by using displays, projectors, cameras, trackers, or other specialized equipment. The most basic method is to superimpose a CG image on a real-world imagery captured by a camera and displaying the combination of these on a computer, tablet PC, or a video projector. In case it is impossible to mount a video projector in the operating room, a portable video projection device has been designed. The main advantage of AR is that the surgeon is not forced to look away from the surgical site as opposed to common visualization techniques.
At present, the applications of AR are limited by the essential requisite of preoperative 3D reconstructions of medical images.
With advancement in technology in the future, it may be possible to track organ position in real-time without the use of dedicated markers, using various methods for analysis of the operative field

These approaches are based on the usage of computing power to predict and visualize organ movement and deformation. It is also possible to use an RGB (red-green-blue) or range camera to perform registration without the use of markers. On the other hand, Hayashi et al. described natural points of reference as tracking points in the patient’s body for progressive registration of cut vessels as markers. Kowalczuk et al. created a system for real-time 3D modelling of the surgical site, with accuracy within 1.5 mm by using a high definition stereoscopic camera and a live reconstruction of the captured image
Augmented reality can be used effectively for preoperative planning and completion of the actual surgery in timely fashion. The preoperative 3D reconstructed images can be modified and prepared for display in AR systems. Commonly, AR is used for tailoring individually preferred incisions and cutting planes, optimal placement of trocars, or to generally improve safety by displaying positions of major organ components. Another benefit of AR is the ability to aid surgeons in difficult terrain after a neoadjuvant chemotherapy or radiotherapy. AR may be used to envisage and optimize the surgical volume of resection

 

NOSES

Great advances in minimally invasive surgery over the last decade have led to development of various techniques extending the benefits of minimal access surgery to patients with colorectal cancer. However, current minimally invasive approach requires an extra incision at the abdominal wall for specimen extraction, which associated with postoperative pain, increased wound complications including infection, hernia formation and scarring. Natural orifice specimen extraction surgery (NOSES) is featured with the removal of surgical specimen from natural orifice in the avoidance of abdominal incision, which has been considered as an alternative approach to open surgery and conventional laparoscopic surgery in selected patients

According to the routes for specimen extraction in colorectal surgery, NOSES is divided into two categories including transanal- and transvaginal-NOSES. A large amount of research literatures and clinical practice have fully confirmed that the anus is the most ideal orifice to extract colorectal specimen which is more in line with the basic requirements of minimally invasive surgery. the anus. Furthermore, gynecologic tumor resection can also be completed simultaneously by transvaginal specimen extraction

NOSES is a very complex procedure and should be performed by experienced surgeons for conventional laparoscopic or robotic colorectal surgery. This is a very important prerequisite for surgeons to start NOSES. A more experienced surgeon in minimally invasive surgery may achieve a shorter learning curve for NOSES. NOSES also has specific indication requirements, including: the depth of tumor invasion should be T2 or T3, the CDmax of specimen should be less than 3 cm for transanal-NOSES and 3–5cm for transvaginal-NOSES, body mass index (BMI) should be less than 30 kg/m2 for transanal-NOSES and less than 35 kg/m2 for transvaginal-NOSES.


 NOSES is also recommended for benign tumors, Tis and T1 tumor when local excision is not indicated for whatever reasons. Finally, transvaginal-NOSES is best to be avoided in young women who have not completed their family.
Despite its clear advantages, the difficulty of the procedure, has not let the procedure to gain wide spread.
The robotic platforms with their technological advantages could also help to spread the technique more.