Robotic Colorectal Surgery using Senhance® Robotic Platform: Single Center Experience with First 13 Cases

. Until recently, robotic surgery has been associated only with da Vinci robotic system. A novel Senhance® robotic system (TransEnterix Surgical Inc., Morrisville, NC, USA) has been introduced almost 5 years ago. Published reports on experience in colorectal surgery using this robotic platform is very limited. We present a prospective analysis of first 13 robotic colorectal surgeries in Klaipėda University Hospital, Klaipėda, Lithuania. 13 patients underwent various colorectal resections: 10 for colorectal cancer and 3 for colonic polyps. 7 were men and 6 women, age range 32–77 years, on an average 56 years. Among 10 patients with colorectal cancer, 3 had stage I, 3 stage II, 3 stage III and 1 stage IV colorectal cancer. 2 patients were operated for unremovable ascending colon adenomas and 1 underwent prophylactic subtotal colectomy with ileorectal anastomisis for familial adenomatous polyposis. Complication occurred in 1 case (7.7%). This patient underwent robotic abdominoperineal resection for low rectal cancer, developed postoperative bleeding from perineal wound on day 7 and had to be taken to operative room for oversuturing the bleeding vessel. Operative time was on an average 3 hours 50 minutes, ranging from 2 hours and 55 minutes to 6 hours and 10 minutes. In-hospital stay ranged from 5 to 16 days, on an average 7 days. Conclusion. Our experience with different types of robotic colorectal resections allows us to state that Senhance® robotic system is fea- sible and safe for colorectal surgery, and wider implementation of this system in our specialty worldwide is simply a question of time.


Introduction
The possibility of performing minimally invasive (laparoscopic) colorectal surgery, including colon cancer, has been demonstrated more than a quarter of a century ago [1]. Since then and already quite a while ago, we learned about the safety of laparoscopic surgery for colon cancer [2][3][4]. There have been a number of trials in favor of laparoscopic rectal cancer surgery, though two relatively recent non-inferiority trials have put certain doubt on laparoscopic rectal cancer surgery in comparison with the open approach [5][6]. Robotic colorectal surgery has long traditions as well, using da Vinci robotic system, which has been the only option for performing robotic surgery for years. The first robotic operation has been performed on a human in 1997 [7]. It seems to be reasonable to expect that robotic approach which has technological privileges including improved view and articulating instruments would help to perform surgeries in narrow spaces such as pelvis in rectal cancer surgery. There was a lot expected from ROLLARR randomized clinical trial [8] to give a solid background for this new type of surgery applied for rectal cancer, to demonstrate it superiority compared to conventional laparoscopy at least in terms of risk of conversion, but neither this nor secondary rectal cancer specific endpoints of this trial did show any difference between the two groups. The proof is still to be provided in future.
Robotic surgery using Senhance® robotic system (TransEnterix Surgical Inc., Morrisville, NC, USA) has been started in Klaipėda university hospital in Lithuania on November 19, 2018. In fact, first two robotic surgeries (first not only in Lithuania and in the Baltic countries as well) were colorectal resections for colon and rectal tumors. Since the first single center series on colorectal surgery using this robotic system in the world [9] there have been just a couple more, and we hope that this article on our first experience in Klaipėda will add to the evidence of feasibility of this robotic system for colorectal surgery.

Patients and methods
Prior to the start of robotic surgery with Senhance® robotic system in Klaipėda University Hospital, our team (divided into two separate groups) consisting of two surgeons, two gynecologists, two urologists, three scrub nurses and two anesthesiologists went to the Senhance® training center in Milan, Italy. Training consisting of introduction to this robotic platform and a hands-on two day dry lab training with third day wet lab, performing various surgical procedures with this system on pigs, having a proctor who had large experience with this kind of surgery on humans.
November 19, 2018 to April 1, 2019 more than 100 procedures using Senhance® robotic platform have been performed in general and colorectal surgery, gynecology and urology. Among them, 13 patients underwent various colorectal resections: 10 for colorectal cancer and 3 for colonic polyps. 7 were men and 6 women, age range 32-77 years, on an average 56 years. Among 10 patients with colorectal cancer, 3 had stage I, 3 stage II, 3 stage III and 1 stage IV colorectal cancer. 2 patients were operated for unremovable ascending colon adenomas and 1 underwent prophylactic subtotal colectomy with ileorectal anastomosis for familial adenomatous polyposis. All selected patients would otherwise undergo laparoscopic surgery. Informed consent was obtained in each case. Robotic surgery was started in each case like a typical laparoscopic case, inserting the first trocar just below the umbilicus, creating pneumoperitoneum and investigating the abdominal cavity. Other trocars were inserted depending on the type of surgery which was planned to be performed, trying to put two working port of the robotic arms a bit further away from the operation field in comparison to laparoscopic approach. After all the trocars were in place, robotic arms were docked. In all cases performed, so far we used only 3 robotic arms. For the right hemicolectomy, all the three robotic arms were on the left side of the patient. For sigmoid and rectal resections, one robotic arm was on the right side and two on the left side. While performing subtotal colectomy, we used the same position of the robotic arms as for the latter surgery, but we had to re-dock the arms several times during this more complex multiquadrant procedure. In the cases of right hemicolectomy, both ligation of the vessels and anastomosis were performed after making a 5 to 6 cm transumbilical incision and exteriorizing the surgical specimen. In cases of sigmoid and rectal resections, ligation of vessels was performed laparoscopically after mobilizing the inferior mesenteric artery and vein using Echelon 60 stapling device. In case of prophylactic subtotal colectomy for familial adenomatous polyposis, colon was mobilized close to serosa using Lotus robotic energy source. After sigmoid resection or anterior rectal resection with partial mesorectal excision (PTME) anastomosis was performed laparoscopically using Ethicon 29 or 33 circular stapling device. After TaTME, manual colo-anal side to end anastomosis was performed.

Results
From 13 operations performed, complication occurred in 1 case (7.7%). This patient underwent robotic abdominoperineal resection for low rectal cancer, developed postoperative bleeding from perineal wound on day 7 and had to be taken to operative room for oversuturing the bleeding vessel. Operative time was on an average 3 hours 50 minutes, ranging from 2 hours and 55 minutes for right hemicolectomy to 6 hours and 10 minutes for subtotal colectomy with ileorectal anastomosis. In rectal cancer cases, neither distal nor circumferential margins were compromised. Both patient who underwent TaTME were after long course radiochemotherapy -one underwent TaTME 8 weeks after neoadjuvant treatment and no response, the second one had a recurrence after complete response being in a 'watch and wait' group. In-hospital stay ranged from 5 to 16 days, on an average 7 days. More detailed information about our 13 patients is delineated in Table 1. . Of course, our experience is very limited as well, but so far we didn't have major complications and there was no need for conversion. Even starting other abdominal procedures at the same time and not having a possibility to get larger experience with the platform with more simple general surgical procedures, we performed a variety of different and complicated colorectal procedures, and after this experience, only our right hemicolectomy seems to bet closer to more or less routine procedure for us. This was the reason for longer duration of the operating time. Our pathological specimens were adequate and in no case oncologic safety was compromised among 10 patients undergoing robotic surgery for cancer.

Conclusion
Our experience with different types of robotic colorectal resections allows us to state that Senhance® robotic system is feasible and safe for colorectal surgery, and wider implementation of this system in our specialty worldwide is simply a question of time.