Endoscopic transnasal surgery for pure intradural lesions—balance between advantages and disadvantages

Abstract

While reading the table of contents, the readership may askthe following question: Another report on endoscopictransnasal resection of tuberculum sellae meningiomas? Isthere really a need for publication? In my personal view,yes, there is!During the last few years, more and more skull basesurgeons have expanded their surgical armamentarium bythe endoscopic transnasal approach. The most commonpathology treated by this approach is pituitary lesions, butalso, the extensions into the anterior, middle and posteriorfossas are more and more frequently described. Looking atthe number of publications on transnasal endoscopic skullbase surgery, one might get the impression that it is amainstream trend followed by a growing part of skull basesurgeons.Regarding, specifically, tuberculum sellae meningiomas,one might now ask for the rational of the trend towardsendoscopic surgery. What are the particular pros and consof this technique? Furthermore, is this evidence-basedpractice?The following advantages and disadvantages are com-monly discussed.The advantages of the transnasal approach:– No brain retraction due to the route comparable to ameningioma of the convexity– First detachment of the tumour matrix– Critical structures like optic nerve or perforators are notobstructing forward view.The disadvantages of the transnasal approach:– The endoscope only enables 2D recording.– Manoeuvrability of the instruments is restricted by thedepth of the operative field and the narrowness of theavenue– intricate dura—and cranioplasty with high rate ofcerebrospinal fluid (CSF) fistulas– limited control of vascular lesions, i.e. carotid arterybleeding.The evidence upon the resection of a tuberculum sellaemeningioma via the transnasal endsocopic route is limited.Only a few series have been published [1, 2, 3, 4] with onlya limited number of patients. According to the levels ofevidence-based medicine, surgery via the transnasal endo-scopic approach is, to date, at level B. To achieve moresignificant results, publications with an increasing numberof treated patients in the level B or a publication in level A,a randomised controlled clinical trial comparing the goldstandard, which is the transcranial microscopic surgeryversus the transnasal endoscopic technique would be mostdesirable. In regard to the categories of recommendation, thepublishedseriessupportarecommendationonlevelC(atleastfair scientific evidence suggests that there are benefitsprovided by the clinical service, but the balance betweenbenefits and risks are too close for making general recom-mendations. Clinicians need not offer it unless there areindividual considerations).From my personal experience with endoscopic transnasalsurgery of tuberculum sellae meningiomas and the perspec-tive from a skull base surgeon, the publication of Ceylan andcoworkers might be criticised in crucial points. In threepatients, subtotal resection of the tumour was achieved. Forfrontobasal meningiomas, gross total resection is the goal.Simpson grade I resection can be achieved via a transcranial