Page 588 - Read Online

Kavalukas et al. Mini-invasive Surg 2020;4:61 I http://dx.doi.org/10.20517/2574-1225.2020.71 Page 5 of 8

Urogenital/sexual function
Pelvic dissection carries a risk of urogenital dysfunction secondary to nerve injury, particularly during
total mesorectal excision. Injury to the hypogastric plexus in the presacral space and the pelvic splanchnic
nerves (nervi erigentes) in the pelvic sidewall can cause significant morbidity. Postoperative urinary
retention and erectile dysfunction may result from damage to these nerves. Proposed benefits of the robotic
platform include more precise dissection afforded by the wristed instruments and better depth perception
due to the binocular lens. These two advantages are postulated to help identify and preserve these nerve
branches to reduce morbidity. There is consensus in the literature that postoperative urinary function
scores in women fail to show a difference between robotic and laparoscopic surgery [29,34,35] . The standardized
International Prostatic Symptom Score is typically used to measure male urinary function scores. Two
prospective studies, as well as a meta-analysis, failed to show a major difference in male urinary symptoms
at multiple time points postoperatively when comparing the two surgical techniques [29,34,36,37] . Other studies
revealed only minor differences regarding an earlier return to baseline function, or shorter time to catheter
removal [30,35] .

Sexual function returns faster in patients after undergoing robotic procedures vs. traditional laparoscopy.
Reviewing quality of life and sexual outcomes in robotic surgery specific to rectal cancer, there was no
difference in erectile function comparing high vs. low anterior resection vs. abdominoperineal resection.
[38]
Luca et al. examined only robotic procedures and reported a decrease in erectile dysfunction compared
to baseline at 3 and 6 months, but returning to baseline in one year. The literature comparing sexual
function after robotic vs. laparoscopic resection consistently demonstrates favourable outcomes for robotic
surgery. A case-matched comparison between laparoscopic and robotic procedures revealed no change
from baseline at one year, however the robotic group had significantly better erectile function within the
[36]
first six months . Another comparative study supported these findings which found that male sexual
function scores deteriorated across all components of the questionnaire in the laparoscopic group but not
in the robotic group . Given this review of the literature, urinary outcomes are comparable between the
[35]
groups, however the data favours robotic surgery for earlier return to baseline sexual function.

Learning curve
Transitioning from open procedures to minimally invasive techniques can be a daunting task for the
surgeon. While both robotic and laparoscopic surgery are an entirely new skill set, it is postulated that
the robotic platform facilitates this shift to modern surgical techniques. Patient outcomes and surgical
efficiency are standard outcomes for measuring the learning curve for these operations. The literature
supports a rather short learning curve for the robotic platform, as many surgeons are already experienced
in laparoscopic surgery and quickly make the adjustment to robotics. A systematic review of the learning
curve evaluated by operative times found a range of 5 to 310 cases for laparoscopic surgery (most were in
[39]
the range of 35-50), and 15 to 30 cases for robotic surgery . Other studies also support a case volume of
50-80 laparoscopic vs. 20-50 robotic surgeries is necessary to attain proficiency [10,40,41] .

A unique study investigated the simultaneous learning curves of a surgical fellow/trainee by evaluating
both laparoscopic and robotic right hemicolectomy operative times. The numbers of procedures required
to identify a decrease in operative time was determined to be 16 for robotic surgery and 25 for laparoscopic
[42]
surgery . There is evidence that surgeons with little to no laparoscopic experience can successfully
transition directly to the robotic platform. Kim et al. compared two surgeons performing 100 rectal
[43]
cancer cases, one of which had performed less than 30 laparoscopic procedures vs. a surgeon that had done
over 300 laparoscopic surgeries. The inexperienced minimally invasive surgeon showed a marked decrease
in operative time after 17 cases and had shorter operative times at the completion of the study without any
difference in oncological outcomes compared to the seasoned laparoscopist. In conclusion, the learning
curve for robotic surgery is faster than laparoscopy, and feasible for all experience levels.