Review Reports - Transnasal Endoscopic Pituitary Surgery—The Role of a CT Scan in Individual Tailoring of Posterior Septum Size Resection

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I suppose that the relation between the mean septal resection and the intercarotid distance could be relevant if you had more patients.

Author Response

Dear reviewer thank you very much for your comment,

we agree, sadly we are not able to enlarge the sample of patients right now.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors evaluated the possibility of predicting the minimum size of septal resection for safe tumor extraction in endoscopic trans-nasal pituitary adenoma resection from preoperative computed tomography scans. They performed a retrospective analysis of CT scans on 20 patients who underwent endoscopic pituitary surgery Virtual insertion of the straight instrument into the sphenoid cavity was simulated using a CT scan and the minimum septal resection size was predicted and compared to various diameters in the nasal cavity. The results were then compared with cadaveric dissections, in which septal resections in 1 cm and 2 cm distances from the anterior sphenoid wall were performed. The authors conclude that 1 cm resection is basically sufficient for a non-extended pituitary tumor extraction.

Although the authors present a meticulous anatomic study providing a comparison between the minimum septal size of resection to other intranasal anatomical measurements, their main conclusion remains theoretical and is just of academic interest.

The endoscopic surgeon needs to adapt and individualize the amount of surgical exposure, including posterior septum resection, in each case. There are many other factors such as tissue resistance, the size of the turbinates, the volume of the nasal cavity and paranasal sinuses which may be relevant for the minimum necessary septum resection to gain save surgical maneuverability and also a comfortable surgical field.

It would be more interesting to know, how the size of posterior septal resection relates to clincal outcome concerning postoperative nasal functions. Unfortunately, this question remains unanswered.

In summary, I need to point out that this paper is only of academic interest and not clinically relevant for the surgical practice.

Comments on the Quality of English Language

minor editing

Author Response

Dear reviewer, thank you very much for your comments.

The first part of the manuscript is mainly theoretic work and we agree and also mention the limitations of tissue resistence in discussion, but the cadaver part with the virtual CT resection and the real life surgery showed a promising sing of possibility to translate CT modelling to real life surgery (the areas that could be reached on cadavers with straight instrument were identical on CT modelling and life resection). However we are aware of small sample size and agree that any real life aplication needs more extensive study.

Real life application of this idea also with nasal functions testing before and after surgery (smell, patency, crust forming, secretion and other) is being now prepared in our department, the results should be out by the end of 2024.

Reviewer 3 Report

Comments and Suggestions for Authors

Interesting presentation of the amount of septal resection in pituitary surgery.

However, I would suggest some comments.

- The author should talk about paraseptal transnasal approach

- Patient population and type of adenoma should be described in the methods as some inclusion criteria for patient selection. So I would suggest to talk about "the surgical space needs to reach the sellar region".

- The author should also take into account some issues related to the patients: any natural septal deviation that may influence the width of the posterior septal removal; previous cacaine abuse/trauma/surgeries to septal bone, recurrence of pituitary surgeries should be defined before patient selection or should be clarified in the enrolled patients by the historical medical records.

Introduction: redundance of the word resection.

Materials and methods: in the images provided I cannot see any white cross but only white stars and white and black asteriscs. So please clarify better the images and methods of measurement, because it's not clear from the text.

The statistical analysis (type of analysis i.e. univariate, t-student or chi-square) should be clarified as well as the type of program used for statistics.

Results: Please correct typing mistakes such as "intercarotic". Please provide a table to summarize the variables compared

Discussion: the author discusses "non-extended tumor". Which type of tumor? adenoma? CFR? meningioma? and if the author discusses the size of tumor, the size should be mentioned in the method section.

Limitations: where is this section? the study has several limitations such as a small sample, bias of selection of patients and comparison between in vivo models with mucosal soft tissue covering the bone that may have an impact on the measurements. Comparison with only two cadevers vs 20 pts is to be considered as variables not equally distributed.

Conclusion: if the author says "A bigger septal resection allows better maneuverability and overview of the operated area" the study he has provided doesn't make any sense if he wants to preserve the olfactory function.