Robotic Low Anterior Resection: Fully Robotic Technique

Fig. 8.1

Robotic cart position for single-docking fully robotic anterior resection of the rectum

Patient positioning: the patient is placed in a modified lithotomy position at 15/30° Trendelenburg tilted to the right side to free the operative field from the bowel loops. The patient’s arms are secured to the body to allow enough space for an assistant operating from the right flank.

Trocar placement: the layouts of the port placement presented in the literature differ from each other although the shared aim was to find a configuration that could maximize the workspace while at the same time reducing the risk of collision between the robotic arms [19].

It is crucial to keep a distance of at least 8 cm between the ports and to verify that the angle between the robotic arms is the widest possible. In fact, the smaller the angle between the robotic arms, the greater the chance of extracorporeal collision between them. Moreover, one should take into account that for geometrical reasons the angles become narrower as the instruments get closer to the lateral limits of the operating field. The solutions adopted by the authors to minimize this limitation consisted either in using only three robotic arms for the first surgical phase and dock the fourth only for the TME or by swapping the positions of the trocars (Fig. 8.2).

Fig. 8.2

Port placement schemes in use for fully robotic single-docking anterior resection of the rectum

Noteworthy is the “arm flipping technique ” in which before proceeding to the pelvic phase, arm n3 is flipped to the right side of the robotic cart, near the robotic arm n2, and redocked to the same trocar to align the robotic instrument on arm n3 toward the pelvis and maximize the operative field of action of the instruments. The robotic arm, in fact, is disconnected from the trocar, rotated behind the robotic cart, and reconnected to the same trocar but in the opposite side and direction [20].

Fully Robotic “Dual-Stage” Technique

Several descriptions of the dual-stage technique have been reported in the literature [21–23].

For this procedure it is necessary to reposition and redock the surgical cart when passing from splenic flexure mobilization to pelvic dissection.

Robotic cart setup: for primary vascular control and splenic flexure mobilization, the robotic cart is docked in the left upper quadrant area (Fig. 8.3a). Once this phase is completed the cart is moved to approach the patient from the lower left side, angled at approximately 30–45° as in the “single-stage” fully robotic technique(Fig. 8.3b).

Fig. 8.3

Robotic cart positions for dual-docking fully robotic anterior resection of the rectum. Position A. Position B

Patient positioning: during the first phase, the patient is usually placed in the reverse Trendelenburg position tilted to the right side (15–30°). Once the mobilization of the left colon is complete, before redocking the cart from the lower left side, the patient is placed in the Trendelenburg position with the left side up (15–30°) again in the same fashion as in the “single-stage” technique.

Trocar placement: Fig. 8.4 shows the port placement for the vessel dissection and left colon mobilization (A) and for the surgical phase of isolation of the mesorectum (B).

Fig. 8.4

Port placement schemes in use for fully robotic dual-docking anterior resection of the rectum. Position A. Position B

Vascular control and splenic flexure mobilization can often be achieved with only two robotic arms reducing the number of ports needed for the procedure.

Instrument use: several methods have been described and are available in literature regarding the use of instruments; therefore, general technical descriptions will be provided.

Both fully robotic techniques are essentially divided into two surgical steps. The first incorporates the isolation of the inferior mesenteric vessels and the mobilization of the mesocolon; the second, the isolation of the mesorectum.

The exposure and division of the inferior mesenteric vessels can either start with the vein or with the artery depending on the anatomical characteristics of the patient and on the surgeon’s preference.

In general, the primary exposure and high ligation of the IMV permits an easier identification of the plane between Toldt’s fascia and the left mesocolon (Fig. 8.5). On the other hand the vertical traction of the mesosigmoid and the incision of the peritoneum on the right side at the promontory facilitate the division of the artery at origin and the preservation of the superior hypogastric plexus, especially in high BMI patients when the IMV is not easily localized (Fig. 8.6).

Fig. 8.5

Medial-to-lateral dissection : hypogastric nerve, ureter, and gonadal vessels are progressively identified

Fig. 8.6

Incision of the peritoneum at the promotory. Vertical traction of the mesosigmoid opens the angle between aorta and IMA (a) and facilitate the preservation of the superior hypogastric plexus (b)

For the vascular phase and left colon mobilization, the instruments are used as follows. One of the robotic arms mounts the dissecting instrument: an ultrasonic device, monopolar hook, or robotic scissors. A second arm mounts a Maryland or bipolar grasper. The assistant holds the suction irrigation device or the laparoscopic clip applier through the assistant’s trocar.

Once the descending and sigmoid colon are completely freed, the splenic flexure is mobilized.

In the second phase, the dissection continues in the pelvis with the incision of the peritoneum and the complete isolation of the rectum, preserving the mesorectal fascia , in accordance with the principles of total mesorectal excision (Figs. 8.7 and 8.8).

Fig. 8.7

Total mesorectal excision . The arrows show the hypogastric plexus

Fig. 8.8

Robotic TME specimen showing shiny intact mesorectal fascia

For the TME , the robotic arm corresponding to the surgeon’s predominant hand mounts the instrument for dissection. In this case, the monopolar hook should be avoided in order to reduce the risk of thermal injury to the nervous branches directed to the genitourinary structures. The second arm mounts a grasper and is used for traction and dissection by the surgeon, while a third arm, usually placed in the left iliac fossa or in suprapubic region, harbors another grasper and helps dissection by granting a stable retraction of the tissues or by lifting up the uterus and/or the bladder. The assistant at the operating table holds the suction irrigation device and provides countertraction of the rectum facilitating the dissection (Fig 8.9).