Other technological advantages include downscaling of movements, absence of tremor, and stillness. In laparoscopy the amplitude of movement of the tip of the instrument is the same as the amplitude of the movement of the surgeon’s hands, whereas in robotics it can be downsized, resulting in increased precision. The computerized interface between surgeon hands and robotic instruments eliminates unwanted tremor, increasing precision. When placed in a specific position, such as for retracting bowel or uterus, the robotic instruments remain in place until repositioned, which can be a difference from human assistance.
The lack of tactile feedback (haptics) is a drawback for the neophyte, but the stereoscopic view rapidly compensates for it. There is a degree of resistance felt at the hand controls of the console, which, coupled with the stereoscopic view, allows the surgeon to determine the consistency of tissues, whether soft or hard, such as “to palpate” the rim of the cervical cup of a uterine manipulator, or “feel” a hard probe introduced in the rectum. The lack of tactile feedback is an advantage when operating in obese patients, because the surgeon cannot feel the resistance of the instruments being inserted through a thick abdominal wall, a difference from laparoscopy.
Another potential advantage of the robotic laparoscopy technique compared to laparoscopy without the assistance of robotics is that it may decrease the number of injuries in surgeons.
There are multiple reports of laparoscopic-related surgeon morbidity syndromes, resulting from the unnatural forced position of wrists, fingers, elbows, and shoulders and the awkward standing position of the surgeon (13). A recent study revealed a lower number of surgeon injuries and lower perception of surgeon’s pain, numbness, and fatigue using robotics compared to conventional laparoscopy (14).
Instrumentation Two of the most important differences between conventional laparoscopic instruments and robotic instruments are articulation and intuitive movements. The tip of a laparoscopic instrument is rigid and the instrument only has 4 degrees of freedom. The tip of robotic instruments are articulated with 7 degrees of freedom, reproducing the movements of the human wrist and fingers (Fig. 25.3) (EndoWrist instruments, Intuitive Surgery Inc, Sunnyvale, CA). The articulation allows the performance of complex maneuvers in small spaces; it accommodates the instrument to the correct plane of dissection (instead of forcing the tissue to the direction of the instrument as in laparoscopy), eliminates changing instruments from one port to another as in conventional laparoscopy, and facilitates suturing and intracorporeal knot tying. As indicated above, the movement of the robotic instruments is intuitive, following the movement of the surgeon hands.
Types of Instruments
Robotic instruments useful for gynecological surgery include ProGrasp forceps, PK dissecting forceps, tenaculum forceps, SutureCut needle driver, monopolar curved scissors, and monopolar cautery spatula (Fig. 25.5A-F).
Trocars The robotic trocars are metallic and have three different types of obturators: blunt, tissue-spreading, and cutting (Fig. 25.4). The robotic trocars are placed in a different configuration than conventional laparoscopy trocars because of technical limitations imposed by the robotic arms. They are usually placed at the level of the umbilicus or higher for pelvic surgery and must be 10 cm apart from each other and from the laparoscope to prevent collision of the robotic arms (Fig. 25.8). At least one assistant trocar is necessary, which must be placed 3 to 5 cm away from any of the other trocars.
Figure 25.8 Trocar position for robotic pelvic surgery. The optical trocar is at the umbilicus. Two robotic trocars are placed 10 cm lateral to the right and left of the umbilicus, respectively. The assistant white trocar is 3 cm cranial and equidistant between the umbilical and left robotic trocar. An additional robotic trocar is 3 cm cranial and equidistant between the umbilical and the right robotic trocar.