Comparison of Transoral Robotic Thyroidectomy and Transoral Endoscopic Thyroidectomy via Vestibular Approach Using an Endoscopic Retractor: A Single-Center Experience

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript presents a retrospective comparison between transoral endoscopic thyroidectomy via vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) in 400 patients affected by papillary thyroid carcinoma, all operated on by a single surgeon using a dedicated endoscopic retractor. The topic is timely and clinically relevant, as transoral approaches are increasingly adopted in thyroid surgery. The large sample size, the standardized surgical technique, and the analysis of the learning curve represent important strengths of the study. However, some considerations and modifications must be made prior to publication.

 

• Only tumor size is reported, while thyroid gland volume/size is not mentioned. Thyroid size may significantly influence surgical difficulty, operative time, and lymph node dissection and should be included in the analysis, if available.
• Long-term oncologic outcomes (recurrence rate, disease-free survival, follow-up duration) are not reported. It has been three years since the end of data collection, please add it.
• Postoperative complications are insufficiently reported. Specific rates of transient and permanent recurrent laryngeal nerve palsy, hypocalcemia, hematoma, and infections should be clearly presented in a comparative table.
• The manuscript uses the terms “bilateral thyroidectomy” and “unilateral thyroidectomy.” The correct surgical terminology should be “total thyroidectomy” and “hemithyroidectomy,” respectively, and this should be corrected throughout the text.
• The Methods section refers to a paired t-test, but the comparison involves independent groups. This should be corrected to an independent samples t-test.
• The statistically significant difference in length of hospital stay (2.29 vs 2.54 days) appears to have limited clinical relevance and should be discussed more cautiously.

Author Response

Comments 1 : This manuscript presents a retrospective comparison between transoral endoscopic thyroidectomy via vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) in 400 patients affected by papillary thyroid carcinoma, all operated on by a single surgeon using a dedicated endoscopic retractor. The topic is timely and clinically relevant, as transoral approaches are increasingly adopted in thyroid surgery. The large sample size, the standardized surgical technique, and the analysis of the learning curve represent important strengths of the study. However, some considerations and modifications must be made prior to publication.

 

• Only tumor size is reported, while thyroid gland volume/size is not mentioned. Thyroid size may significantly influence surgical difficulty, operative time, and lymph node dissection and should be included in the analysis, if available.
• Long-term oncologic outcomes (recurrence rate, disease-free survival, follow-up duration) are not reported. It has been three years since the end of data collection, please add it.
• Postoperative complications are insufficiently reported. Specific rates of transient and permanent recurrent laryngeal nerve palsy, hypocalcemia, hematoma, and infections should be clearly presented in a comparative table.
• The manuscript uses the terms “bilateral thyroidectomy” and “unilateral thyroidectomy.” The correct surgical terminology should be “total thyroidectomy” and “hemithyroidectomy,” respectively, and this should be corrected throughout the text.
• The Methods section refers to a paired t-test, but the comparison involves independent groups. This should be corrected to an independent samples t-test.
• The statistically significant difference in length of hospital stay (2.29 vs 2.54 days) appears to have limited clinical relevance and should be discussed more cautiously.

 

Response 1 :  his manuscript presents a retrospective comparison between transoral endoscopic thyroidectomy via vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) in 400 patients affected by papillary thyroid carcinoma, all operated on by a single surgeon using a dedicated endoscopic retractor. The topic is timely and clinically relevant, as transoral approaches are increasingly adopted in thyroid surgery. The large sample size, the standardized surgical technique, and the analysis of the learning curve represent important strengths of the study. However, some considerations and modifications must be made prior to publication.

 

• Only tumor size is reported, while thyroid gland volume/size is not mentioned. Thyroid size may significantly influence surgical difficulty, operative time, and lymph node dissection and should be included in the analysis, if available.

• We agree with your suggestion; however, data regarding thyroid gland size were not included in the present study. Future research will aim to incorporate this parameter for a more comprehensive analysis.

• Long-term oncologic outcomes (recurrence rate, disease-free survival, follow-up duration) are not reported. It has been three years since the end of data collection, please add it.

• We agree with your valuable comment. Additional research addressing this issue is currently underway. We have included this point in the Limitation section of our revised manuscript.

• Postoperative complications are insufficiently reported. Specific rates of transient and permanent recurrent laryngeal nerve palsy, hypocalcemia, hematoma, and infections should be clearly presented in a comparative table.

• Among the patients who underwent TOETVA, only one case of transient hypocalcemia was observed. Therefore, a separate table was not created for this complication. No other postoperative complications were observed.

• The manuscript uses the terms “bilateral thyroidectomy” and “unilateral thyroidectomy.” The correct surgical terminology should be “total thyroidectomy” and “hemithyroidectomy,” respectively, and this should be corrected throughout the text.

• We agree with your opinion. We corrected it and highlighted.

• The Methods section refers to a paired t-test, but the comparison involves independent groups. This should be corrected to an independent samples t-test.

• We agree with your opinion. We corrected it and highlighted.

• The statistically significant difference in length of hospital stay (2.29 vs 2.54 days) appears to have limited clinical relevance and should be discussed more cautiously.

• We agree with your opinion. We have added a corresponding statement to the discussion section and highlighted it.

 

Reviewer 2 Report

Comments and Suggestions for Authors

Although the Discussion mentions the limitations, they should be more clearly emphasized, particularly:

a. Time-period differences between groups

TOETVA cases began in 2016, TORT in 2020.
Thus, surgeon maturation bias exists:

• More complex TOETVA cases may appear later in the timeline.

• Surgeon skill improved over years, benefiting TORT results.

Recommendation:
Add explicit acknowledgement of temporal bias, possibly include a sensitivity analysis or discuss how many TOETVA cases occurred after TORT introduction. 

You report significant differences in:

• Tumor size (TORT larger; P = 0.004)

• Sex distribution (P = 0.021)

• Lymphocytic thyroiditis incidence (P = 0.002)

These differences may influence intraoperative difficulty and postoperative recovery.

Recommendation:
Discuss how these variables might confound the outcomes.
A multivariate regression would strengthen findings, even if only exploratory.

Author Response

Comments 2 : Although the Discussion mentions the limitations, they should be more clearly emphasized, particularly:

1. Time-period differences between groups

TOETVA cases began in 2016, TORT in 2020.
Thus, surgeon maturation bias exists:

• More complex TOETVA cases may appear later in the timeline.
• Surgeon skill improved over years, benefiting TORT results.

Recommendation:
Add explicit acknowledgement of temporal bias, possibly include a sensitivity analysis or discuss how many TOETVA cases occurred after TORT introduction. 

You report significant differences in:

• Tumor size (TORT larger; P = 0.004)
• Sex distribution (P = 0.021)
• Lymphocytic thyroiditis incidence (P = 0.002)

These differences may influence intraoperative difficulty and postoperative recovery.

Recommendation:
Discuss how these variables might confound the outcomes.
A multivariate regression would strengthen findings, even if only exploratory.

Response 2 : Although the Discussion mentions the limitations, they should be more clearly emphasized, particularly:

1. Time-period differences between groups

TOETVA cases began in 2016, TORT in 2020.
Thus, surgeon maturation bias exists:

• More complex TOETVA cases may appear later in the timeline.
• Surgeon skill improved over years, benefiting TORT results.

Recommendation:
Add explicit acknowledgement of temporal bias, possibly include a sensitivity analysis or discuss how many TOETVA cases occurred after TORT introduction. 

• We agree with your opinion. We have added a corresponding statement to the discussion section and highlighted it. We have added a paragraph acknowledging the potential for temporal bias in the discussion section. As for the additional analysis you suggested, we plan to address it in a future study. We appreciate your understanding.

 

You report significant differences in:

• Tumor size (TORT larger; P = 0.004)
• Sex distribution (P = 0.021)
• Lymphocytic thyroiditis incidence (P = 0.002)

These differences may influence intraoperative difficulty and postoperative recovery.

Recommendation:
Discuss how these variables might confound the outcomes.
A multivariate regression would strengthen findings, even if only exploratory.

• We agree with your opinion. We have added a statement in the discussion section acknowledging that the mentioned variables may act as potential confounding factors. Multivariate regression analysis will be considered in future studies. We appreciate your understanding.