Retzius-Sparing Robot-Assisted Radical Prostatectomy Using the Hinotori Surgical Robot System Platform: Report of the First Series of Experiences

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is the first report about rs-RARP using Hinotori platform.

However, only 6 cases were reported, and the reviewer recommends authors to increase the number of the cases.  The number of cases included in the article is too small to draw any conclusions.  Basically the procedures presented in the article seems to be no difference between Hinotori and DaVincit platform, please provide actual economic advantages using Hinotori.

Also please provide information whether one surgical doctor had performed rs-RARP using the two platforms or not.

 

Author Response

Comments1:

This is the first report about rs-RARP using Hinotori platform.

However, only 6 cases were reported, and the reviewer recommends authors to increase the number of the cases.  The number of cases included in the article is too small to draw any conclusions.  Basically the procedures presented in the article seems to be no difference between Hinotori and DaVincit platform, please provide actual economic advantages using Hinotori.

Also please provide information whether one surgical doctor had performed rs-RARP using the two platforms or not.

Response1: 

Thank you for the comment. My initial submission was “Case reports” and thus the number of cases of RS-RARP were 6. However, the assistant editor offered us for a more detailed manuscript and correction to “Original article” type, given that there are 14 cases of da vinci cases with a total of 20 cases. This is a preliminary report and we will provide new data with more number of cases in the years to come. We added this limitation in the discussion and conclusion in lines 234-236; “This study has several limitations one of which is the small number of cases. Due to the small number of cases, it maybe early to draw any clinical conclusion but at least in the first 6 cases, hinotori SRS showed similar performance with da Vinci.”, “A larger series of study is required to further assess the performance of this newly developed surgical system.”

A single surgeon performed the rs-RARP in both platforms. This is described in line 107.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is interesting and well written, except for some minor issues (I think the sentences at the end of the discussion, from line 32 to line 35, were inserted into the text by mistake, as they appear to come from a template text).

In any case, I think the paper should be accepted, after that small revision, as the author has provided new insights into the potential of the Hinotori robotic surgical system, particularly in the context of Retzius-sparing prostatectomy which, until now, has never been described.

They have demonstrated the feasibility of the procedure. They will need a much larger series to also study its utility compared to the pre-RARP approach.

 

Comments on the Quality of English Language

English language was used properly.

Don't forget to fix the last lines of discussion

Author Response

Comments:

The paper is interesting and well written, except for some minor issues (I think the sentences at the end of the discussion, from line 32 to line 35, were inserted into the text by mistake, as they appear to come from a template text).

In any case, I think the paper should be accepted, after that small revision, as the author has provided new insights into the potential of the Hinotori robotic surgical system, particularly in the context of Retzius-sparing prostatectomy which, until now, has never been described.

They have demonstrated the feasibility of the procedure. They will need a much larger series to also study its utility compared to the pre-RARP approach.

 

Response: Thank you very much for the kind comment and thank you for pointing out the mistake at the end of the discussion. The sentences from the template text at the end of the discussion were omitted.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors present a pilot study on using the Hinotori device for Retzius-sparing RALP. It is a kind of case series.

I think for the reader the following is important to add:

 

More detailed description and images of the features that are different from Da Vinci

- Trocars not attached,

- semi-lunar arrangement of the arms

- use of 8 axes of the arms

- Did the authors use 30° lens?

- How does the flipping of the camera works?

- What is behind "floating-like sensation of the arms"

- Is this due to the loosening of Bowden-strings (cables) providing 7 DOF?

The readers are interested on all these details. Not only, that the clinical results were comparable.

Author Response

Comments:

The authors present a pilot study on using the Hinotori device for Retzius-sparing RALP. It is a kind of case series.

I think for the reader the following is important to add:

 

More detailed description and images of the features that are different from Da Vinci

- Trocars not attached,

- semi-lunar arrangement of the arms

- use of 8 axes of the arms

- Did the authors use 30° lens?

- How does the flipping of the camera works?

- What is behind "floating-like sensation of the arms"

- Is this due to the loosening of Bowden-strings (cables) providing 7 DOF?

The readers are interested on all these details. Not only, that the clinical results were comparable.

Response:

Thank you for the insightful comments.

Since the “hinotori SRS” was designed as an alternative surgical robot as “da Vinci”, this surgical robot provides similar maneuver unlike other surgical robots that are in use in Japan (e.g. Saroa (Riverfield) and Hugo RAS System (Medtronic)). Images of the hinotori SRS are also similar except that it has high vision image that is already shown in Figure 1B-D. This content is added to the text in lines 207-208; “The merits of using hinotori SRS are the low cost, 3D full high vision (1920 × 1080 pixel)” and in lines 44-49; “ Other surgical robotic system includes the Saroa (Riverfiled) and Hugo RAS System (Medtronic). Saroa is unique since it provides sense of touch to surgeons by using air pressure of pneumatic control. The Hugo RAS System is composed of indivisual arm configurations that allow flexibility in the range of motion. The hinotori SRS was designed very much similar to the da Vinci surgical system which has 4 robotic arms, no sense of touch, similar type of forceps.”

 

As the reviewer pointed out, the trocars are not attached to the “hinotori SRS” and the forceps that are attached to the robotic arms are directly inserted through the trocar. This enables clearance of space around the trocar. On the other hand, the “floating-like sensation of the arms” may be associated with the direct insertion of the forceps. This phenomenon is considered to be caused by the change of volume regarding the pneumoperitoneum. Since the forceps are inserted directly, it has instability when the pneumoperitoneum-volume changes leading to abnormal sensation to the surgeon. Notably, the loosening of the cables providing the Degree of Freedom (DOF) is not reported. This content is described in the text in lines 210-217, “The “floating-like sensation of the arms” may be associated with the direct insertion of the forceps. This phenomenon is considered to be caused by the change of volume regarding the pneumoperitoneum. Since the forceps are inserted directly, it has instability when the pneumoperitoneum-volume changes leading to abnormal sensation to the surgeon. Fortunately, this “floating-like sensation” has already been incredibly improved in the last update on Autumn of 2023. Notably, the loosening of the cables providing the Degree of Freedom (DOF) has not been reported nor considered as the cause of this phenomenon.”

 

As the reviewer pointed out, the trocars were placed in a semi-lunar arrangement. This is described in lines111-112; “Trocars were placed in a semi-lunar arrangement as shown in Fig.1A.”

 

The robotic arms possess 8 axes which makes the arm-movements smooth. This content is already written in ines 50-51, “This surgical platform has arms possessing 8 axes that contribute to more flexible movement and prevent interferrence between arms [3].”

 

The flipping of the camera cannot be performed by one click of a button, instead 1. One click button on the surgeon cockpit, 2. One click button on the camera itself which is done by the assistant, and 3. One more click to flip the image of the camera. It takes roughly 10-15 seconds to complete the procedure. This content is described in lines 223-225; “ Additionally, the flipping of the 30 degrees’ camera from “downward” to “upward” or vice versa requires several steps (10-15 seconds) which makes it time consuming when compared with da Vinci.”

 

The authors use the 30 degree-lens in RS-RARP.

This is described in line 111; “ A 30 degrees-lens were used throughout the surgery.”

Reviewer 4 Report

Comments and Suggestions for Authors

In this study, the authors present their experience with the newly developed Hinotori robotic system for radical prostatectomy. However, several critical issues have been identified.

Introduction:

• The introduction is very brief and does not explore the topic that will be discussed later in the paper.
• The comparison between Retzius-sparing and anterior approaches needs to be more detailed and should be placed as the first paragraph, emphasizing the advantages of the former.

Methods:

• The study does not specify whether it is retrospective or prospective.
• The variables examined need to be clearly stated.
• The perioperative variables considered are too few.
• Why was erectile function not considered?

Results:

• If statistical significance is defined as p < 0.05, why is 0.058 considered significant?

Discussion:

• The functional and oncological outcomes of RARP are not described at all.
• Why do the authors believe console time is longer with this system?
• The study’s limitations are not mentioned.

Conclusion:

• The conclusion is too brief.

Comments on the Quality of English Language

The English appears appropriate, with only a few minor syntactical errors.

Author Response

 Comments 4-1:

In this study, the authors present their experience with the newly developed Hinotori robotic system for radical prostatectomy. However, several critical issues have been identified.

 Introduction:

• The introduction is very brief and does not explore the topic that will be discussed later in the paper.

 

Response 4-1:

We added some description regarding other surgical robots and the standing point of hinotori SRS among these surgical robots in lines 44-50; “Other surgical robotic system includes the Saroa (Riverfiled) and Hugo RAS System (Medtronic). Saroa is unique since it provides sense of touch to surgeons by using air pressure of pneumatic control. The Hugo RAS System is composed of indivisual arm configurations that allow flexibility in the range of motion. The hinotori SRS was designed very much similar to the da Vinci surgical system which has 4 robotic arms, no sense of touch, similar type of forceps.”

Comments 4-2:

• The comparison between Retzius-sparing and anterior approaches needs to be more detailed and should be placed as the first paragraph, emphasizing the advantages of the former.

Response 4-2:

As the reviewer suggested, the paragraph describing rs-RARP is replaced as the first paragraph in lines 36-40; “Retzius-sparing robot-assisted radical prostatectomy (rs-RARP) was first introduced by Galfano A in 2010 [1]. This novel approach is unique since it is not associated with dissection of the Retizus space, providing excellent early recovery of urinary continence [2]. However, this technique is associated with a small working space which makes this procedure very difficult to perform.” Accordingly, the reference number is corrected for reference #1-3.

 

Comments 4-3:

Methods:

• The study does not specify whether it is retrospective or prospective.

Response4-3:

This study was retrospective and we added this description in line 71; “This study was a retrospective study.”

 

Comments 4-4:

• The variables examined need to be clearly stated.

Response4-4:

We added the description of the variables in lines 63-71;” Age, prostate- specific antigen, body mass index, prostate volume, and clinical T stage were investigated for preoperative parameters. Regarding perioperative parameters, console time, estimated blood loss, nerve sparing status, prostate weight, surgical maring status, pathological T status, complications, functional outcomes (immediate urinary continence and sexual function) were investigated. Immediate urinary continence was defined as “using no pads within 24 hours after surgery” and immediate erectile functional recovery was defined as “patient claim of erection or score of more than 0 on Erectile Hardness Score within 24 hours after surgery”.”

 

Comments 4-5:

• The perioperative variables considered are too few.

Response 4-5:

We added preoperative prostate volume. Accordingly, it is added in both the text and in Table 1; In the text lines 63-65, “Age, prostate- specific antigen, body mass index, prostate volume, and clinical T stage were investigated for preoperative parameters.”

 

Comments 4-6:

• Why was erectile function not considered?

Response 4-6:

In this study, we wanted to focus on the immediate functional outcome after rs-RARP, given that all these cases are newly performed with a very short follow-up. Obviously, erectile functions do not recover in the early stages after RARP. If we waited for a year or maybe more, this report on rs-RARP by hinotori SRS will be reported by others. However, as the reviewer suggested, we added the parameter “immediate erectile function” to the Tables and the manuscript in lines 68-70, “Immediate urinary continence was defined as “using no pads within 24 hours after surgery” and immediate erectile functional recovery was defined as “patient claim of erection or score of more than 0 on Erectile Hardness Score within 24 hours after surgery”.” and in lines 146-148, “Immediate erectile function was not observed in any of the patients both in hinotori SRS and in the da Vinci group.”.

 

Comments 4-7:

Results:

• If statistical significance is defined as p < 0.05, why is 0.058 considered significant?

Response 4-7:

P value of 0.058 is not considered significant but shows a statistical “tendency”. The sentence in lines 139-140 already describes the content: “There was a tendency for shorter console time in the da Vinci group (P = 0.058).”

 

Comments 4-8:

Discussion:

• The functional and oncological outcomes of RARP are not described at all.
• Why do the authors believe console time is longer with this system?

Response 4-8 (answer to the 2 questions):

We added description regarding this matter in lines 189-197; “Initially, the authors assumed that “floating like sensation” of the arms may influence the surgical snd functional outcome. Fortunately, hinotori SRS showed an excellent resection margin rate for pT2 cases and also showed similar results of recovery of urinary continence. Additionally, we had no unrecoverable malfunctions resulting in conversion to open or laparoscopic surgery. Although the console time was approximately 40 minutes longer with the hinotori SRS, this maybe due to the experience of the surgeon and the assistant. On top of this, the “floating like sensation” may have influenced slower movement of the arms of the robotic system when compared with da Vinci.”

 

Comments 4-9:

• The study’s limitations are not mentioned.

Response 4-9:

We added the limitations of this manuscript in lines 241-244; “This study has several limitations one of which is the small number of cases. Due to the small number of cases, it maybe early to draw any clinical conclusion but at least in the first 6 cases, hinotori SRS showed similar performance with da Vinci. Notably, this study also harbors limitation derived from retrospective nature.”

 

Comments 4-10: 

• The conclusion is too brief.

Response 4-10:

We added volume to the conlusion in lines 247-249; “A larger series of study is required to further assess the performance of this newly developed surgical system.”

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I have no comments for the revised form. It is ready for acceptance if the article is just a case report of six cases.

Author Response

Comments1:

I have no comments for the revised form. It is ready for acceptance if the article is just a case report of six cases.

 

Response: Thank you for your time in reviewing this manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

None

Author Response

Comments:

None.

 

Response: Thank you for your time in reviewing this manuscript.

Reviewer 4 Report

Comments and Suggestions for Authors

The authors adequately replied to my comments. The paper is fine

Author Response

Comments:

The authors adequately replied to my comments. The paper is fine

 

Response:

Thank you for your time in reviewing our manuscript.