perception of tissue marking over surgical time. Overlaid images of white light and NIR/ICG are combined and processed with intelligent analysis software. With a specialized CCU, miniscule fluorescence tonal differences not visible to the human eye are detected and highlighted by a color scale mapping system.
Ranging from blue tones (the weakest fluorescence signal) to yellow/orange (the strongest fluorescence signal), color mapping maximizes early detection of lymphatic circulation, and SLN. The color grading system also positively influences the distinction of SLN from subsequent lymph nodes, which can be very helpful in surgical decision making.
The standard endoscopic imaging systems provide the surgeon with indirect monocular views of the operative field, denying the operator the binocular depth cues that provide a sense of stereopsis. The loss of binocular vision in a two‐dimensional (2D) display causes visual misperceptions – mainly loss of depth perception, adding to the surgeon's fatigue.
One of the biggest challenges for laparoscopic surgeons is hand–eye coordination within a 3D scene observed on a 2D display. Experienced surgeons learn to use monocular depth cues such as light and shade, relative size of objects, object interposition, texture gradient, aerial perspective, and motion parallax instead of stereovision. Using these cues, all laparoscopic operations can be accomplished; however, time and accuracy may be lost as these techniques do not completely compensate for loss of stereoscopic depth perception [23–32].
The 3D HD view with enhanced haptic feedback makes laparoscopic surgery safer and more intuitive. It improves hand–eye coordination and surgical precision, with the use of all conventional instruments. The 3D view provides increased depth perception and more accurate measurement of the dimensions of the anatomical spaces, enhancing the skills of the laparoscopic surgeon to manipulate tissues, dissect, design surgical strategies, and place intracorporeal sutures. Studies have reported less strain on the surgeon when using 3D rather than 2D vision [33–38].
Recent technological advances have led to sophisticated high‐resolution systems and light polarizing glasses that are lighter and more comfortable. A dual‐optical scope is connected to a two‐chip imaging system that transmits two pictures to a stereoscopic screen. When the surgeon wears polarized 3D glasses, the two images are merged by the brain into one single image that gives the perception of depth.
Stereoscopic vision improves accuracy in laparoscopic skills for novices. Several studies demonstrated a marked reduction in the number of repetitions and errors.
Few 3D systems are used yet in veterinary practice, but in the near future as popularity increases and prices are reduced, availability will increase, likely resulting in improved performance of laparoscopic surgical procedures. Nevertheless, when choosing between 3D and ECE (enhanced contact endoscopy) or NIR/ICG, the latter two currently stand as a more rational, cost‐effective options for small animal endoscopy and MIS [39–43].
Display Monitors, Auxiliary Screens, and “All‐in‐One” Video Systems
To achieve superior live images during surgery, the quality of the display monitors and auxiliary screens is as important as any other aspect of the video chain. They vary in size, resolution, inputs, and other features. Monitors 17–26 in. are the most common. Flat screen monitors have replaced the old CRT monitors, as in consumer electronics. The resolution of the monitor should match or surpass the resolution of the other elements of the imaging chain. Surgical display monitors should have a minimum of 500 lines for standard definition single‐chip cameras, 750 lines for standard definition three‐chip cameras, and 1080p to obtain maximum benefit from a full HD camera system [1–5].
Figure 3.9 (A). 4K modular imaging system combining white light and NIR/ICG applications. IMAGE 1 S Connect II and IMAGE 1 S 4U Linc modules. (B). FULL HD 1920 × 1080 all‐in‐one unit consisting of a camera control unit, LED light source, 18.5 in. touch screen (16 : 9 format), digital capture system.
Source: TELEPACK + © KARL STORZ SE & Co. KG, Germany.
Figure 3.10 Insufflators. (A). Veterinary dedicated insufflator with max flow of 20 l/min. (B). State‐of‐the‐art electronic insufflator combined with heating system and a max flow of 50 l/min.
Source: © KARL STORZ SE & Co. KG, Germany
A 4K Image is best displayed on a monitor of 32 in. or more, as smaller monitors do not have the capability of showing the detail generated by a 4K camera.
Ideally, multiple mobile monitors should be situated opposite the surgeon and surgeon's assistants so that each surgical team member has a straightforward view [9,44–48]. Modern FULL HD Compact “all‐in‐one” units typically include a CCU, light source, 18.5 in. monitor, insufflation pump (for flexible endoscopy), screen, and image capture module (Figure 3.9b). These units can provide a FULL HD image connected to rigid endoscopes, traditional and CMOS flexible endoscopes, and newer disposable flexible endoscopes. A dedicated keyboard can be attached, allowing the surgical team to enter patient data, and send it to a hospital network via USB cable or flash drives. These state‐of‐the‐art units also comprise DVI external outputs for the connection of multiple auxiliary monitors [1–5, 8, 13, 14].
Insufflators
A CO2 insufflator is used to create and maintain a working space between the telescope and the target tissues [49, 50]. The insufflator automatically controls CO2 flow rate and pressure throughout the procedure.
The carbon dioxide source is typically a pressurized tank connected to the insufflator with a high‐pressure hose. However, in referral facilities an in‐house gas delivery system may be available. The reduced pressure CO2 gas is delivered to the patient via sterilized tubing that connects from the front panel of the insufflator to the hub of a Veress needle or Luer‐lock connector on a cannula.
An antibacterial sterile filter should be coupled in between the patient insufflation tube and the unit, which prevents contamination from the CO2 tank to the patient or from the patient to the insufflator. The filter also will prevent the entrance of fluid back into the unit thus avoiding permanent damage [1–5, 8,49–51].
Standard veterinary insufflators feature a maximum flow of 20 l/min, since for small animal MIS, it is rarely suggested to use a flow over 2.5 l/min (Figure 3.10a). Nevertheless, advanced models of 40 and 50 l/min are also available, and feature OR integration abilities, thus making possible to control all units from one single station platform. Electronic insufflators with gas heating are available to minimize hypothermia, and generally comprise 50 l/min high flow. (Figure 3.10b) [9].
Capture and Storage
