Review for 10.1186/s12876-021-01834-1 (2021)

Title: Comparison of the operative outcomes and learning curves between laparoscopic and
“Micro Hand S” robot-assisted total mesorectal excision  for rectal cancer: A retrospective study
Version: 1 Date: 19 Apr 2021
Reviewer's report:
Excellent manuscript. Excellent work collecting the data. Good work in order to analyze the
learning curve and report functional outcomes.
An extended video showing the outside view of the robot (whole console of the surgeon and
the robot coming into the patient), as well as an inside video with the instruments moving in
the cavity would be excellent.
ABSTRACT
Background: Mention that you also compare functional outcomes, that is very relevant as not
many studies report functional outcomes and the data is scarce.
Methods: Mention in the abstract that you calculate the learning curve according to the CUSUM
analysis.
INTRODUCTION
Page 4, line 73: surgical challengeS
Page 4, line 78: AND lower incidence of erectile dysfunction
Page 4: line 80: China is a country with a large population of rectal cancer, and therefore the
overall prognosis is relatively worse compared t other countries with lower incidence.
Page 4, line 83: isn’t any commercial industry producing the Micro Hand S robot? Like for da
vinci you would have to mention: Da Vinci ® (Intuitive Inc.) Please add, also when you talk
about the Da Vinci.
Page 4, line 86: Change ¨what´s more¨ for ¨Moreover¨
METHODS
Page 6, line 13: How do you set the learning curve periods (a year for laparoscopy and 18 months
for robotic)? Based on what?
Page 7, line 49: what kind of instruments do you have available with this robot for each working
arm? Grasper? Cutting/sealing device? Scissors? Please add.
Page 7, line 53: please draw the possible second assistant port in Figure 2 to help those using the
robot. How often do you place a second assistant port? Or how comfortable is it to work with
just 4 ports?
Page 8, line 54: is it described elsewhere how to dress the robot, how long does it take? Please
reference it or describe it.
Page 8, line 56: does the robot have a table associated that tilts as needed? Or what do you do if
you need to take down the splenic flexure? Do you undock and redock again?
Page 8, line 158: we LIGATED
Page 8, line 64: using A cutting stapler.
Page 8, line 64: was EXTRACTED
Page 8, line 66: could you use the robot for the anastomosis? Or do you need regular laparoscopic
instruments?
RESULTS
Page 9, line 196: the operative time of the rtme group was slightly longer / longer than that of
the ltme group
Page 10, line 201: none of the patients in either group had an involved DRM. Two patient in the
rtme group were considered to have an involver CRM
Page 10, line 216: two local recurrenceS.
Can you also briefly describe what happened with the local recurrence? Radiotherapy? Chemo?
Abdominoperineal resection?
Page 11, line 215 and 217: which underwent ENDOSCOPIC TREATMENT.
DISCUSSION
Page 15, line 316: similar to 7% of other meta-analysis …. Or … similar to 7% of Wang et al.
meta-analysis.
Page 15, line 326: please, add a reference regarding the reported intact mesorectum rate of 77.5%
in the literature.
Page 16, line 342: tme quality WAS not compromise
Page 16, line 352: BOTH patients
Page 17, line 355: In the methods, you state the functional questionnaires are sent to all patients.
Why is inadequate the data from females? I believe there questionnaires for female functional
outcomes? Then, clarify in the methods that you only give the questionnaires to male patients.
Page 17, line 360: aren´t you performing nerve-sparing rectal cancer surgery both with
laparoscopy and robot? Please review this statement, as probably what you mean is that robot
sparing surgery is not superior to laparoscopic sparing surgery.
Page 17, line 364: did EXIST.
Page 17: This is a single surgeon learning curve. Do you think this data can be extrapolated?
Don’t you think that is another limitation of the study?