Extradural Clinoidectomy in Clinoidal Meningiomas: Analysis of the Surgical Technique and Evaluation of the Clinical Outcome

Round 1

Reviewer 1 Report

The authors present a series of 26 patients with clinoidal meningioma. Extradural clinoidectomy was performed in 15 patients and 11 did not undergo clinoidectomy. All patients had a complete visual and neuroimaging assessment at 1,2,3,6 and 12 months and then compared the results by applying sophisticated statistical tests. The result showed that patients undergoing CE had higher rates of visual improvement and the EOR was significantly higher in patients undergoing CE. The results were impressive but we have some very pertinent questions. According to the Al-Mefty classification, type lll meningiomas are small in the vast majority of cases and are soon manifested by visual problems. Therefore, a Dolenc-type access is not justified for this type of lesion unless they are tumors invading the cavernous sinus. Also, the authors do not mention the volume of tumors that justify this approach. On the other hand, should the authors explain why 11 patients underwent craniotomy without clinoidectomy? and finally, when classifying the degree of removal based on Simpson's classification, they use a method to assess the degree of removal in tumors that invade the cavernous sinus. Type III CM can be safely operated also intradurally and with only removal of the roof of the optic canal, without requiring maneuvers as complex as the one proposed by the authors. The references are up to date and I congratulate the authors for the beautiful surgical technique but I do not agree with the access used for a type III MC.

Author Response

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Reviewer 2 Report

The authors present a review of 26 patients with type III clinoidal meningiomas and compare operative techniques, namely standard pterional approaches and anterior clinoidectomies, as they relate to postoperative outcomes. The authors have several spelling and grammatical errors in the report which need to be addressed. Next, the authors do not sufficiently describe the differences in intraoperative preparation and technique compared to standard approaches. More information can be provided describing the risks and benefits of this new approach. Given that this approach has been described many times in the literature, it is not clear as to what this paper adds, and if it is for advocacy of this approach, it is limited to the experience of this single center, and thus generalizability is limited. How can the authors advocate the use of this approach at a center which is unfamiliar with it, namely, how can a reader apply this information presented into their clinical practice. There are also so many other factors which can impact posteropatve course which are not addressed by the authors. What were the baseline neurological states of the patients, was the OR time or blood loss different between the surgical approaches, was length of stay different? The authors did not include a Table 1 and there is no evidence that the two groups were comparable at baseline. The authors do not describe the decision-making between the two approaches and this inherently will add bias, as surgeons will choose an approach based on the particular anatomy of the lesion, thereby making the groups unequal. There is no comparison of size of the lesions between the two groups. There is finally no labeling on the supplemental video, which may make it difficult for some readers to follow. Narration would be helpful as well. The authors need to address these issues before this report can be considered for publication. 

Author Response

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Round 2

Reviewer 2 Report

The authors do an excellent job addressing the comments made point-by-point. I have no additional concerns about the manuscript.