In Reply

Abstract

We appreciate the positive comments of Simal et al regarding our article.1 It is correct that crusting may last as long as 100 days after a vascularized septal flap (VSF). The limit of 3 months considered in our article was chosen to be able to compare with other articles in which the follow-up was of the same period. Although the present study is limited to 3 months, a longer follow-up is currently being conducted and the data will be analyzed. A recent randomized controlled trial on the transnasal transsphenoidal endoscopic approach compared VSF procedures and synthetic or nonautologous materials for skull base reconstruction. They concluded that transnasal transsphenoidal endoscopic approach results in decreased olfaction, either with or without deploying a septal flap. However, the use of the VSF resulted in a more severe hyposmia at least 6 months after surgery.2 Because the use of VSF is considered as the optimum choice for skull base reconstruction and a prevention of cerebrospinal fluid leaks, the Ethics Committee of our institution was reluctant to allow an appropriate control group without VSF. Vascularized flaps of the lateral nasal wall, as described more recently, may possibly serve as well to reconstruct the skull base without damaging olfactory neuroepithelium.3 None of our patients had a transcribiform tumor, because this was considered an exclusion criterion. We cannot fully follow the descriptions by Simal et al of changing the position of the head. The patient's head must be placed in a 3-pin Mayfield skull clamp during complex skull base surgery. This technique secures the head at an absolute still during delicate drilling procedures and fine intradural maneuvers. In consequence, inadvertent patient movement during surgery can be very dangerous; for this reason, we have to keep in mind that endoscopic skull base surgery shares the same fundamental principles as open skull base approaches. We have already stressed this concept in a recent series report.4 Concerning the angle of approach and its relationships with the patient position, we agree that it is of paramount importance, but it has already been described in some contributions in recent years.5 We have recently published a study on the bony anatomy of the suprasellar region and also analyzed the angle of the approach.6 In this study, we provide a detailed description of the endoscopic endonasal anatomy of this region and evaluate the anatomic conditions that may influence the surgical strategy. In our opinion, this is the main factor that influences a surgical route; the goal of surgery may be achieved only by customizing each procedure on the basis of an individual patient's native anatomy. In our multidisciplinary team, otorhinolaryngologists and neurosurgeons work together to develop comprehensive treatment plans for patients with skull base tumors. Otorhinolaryngologists gently treat nasal mucosa and olfactory epithelium by using 45° endoscopes, which allows observation superiorly toward the olfactory cleft while working with the instruments from below. Subsequently, the surgeon has a perfect view of the border of the VSF at its superior aspect (olfactory sulcus). We agree with the Simal et al comment about conservative procedures in the olfactory dominance side. However, as in audiology, most smell tests depend on patient compliance (“subjective” methods). Future studies examining the impact of skull base approaches on olfaction by using objective measures (olfactory-evoked potentials, functional magnetic resonance imaging, and functional positron emission tomography) are needed to measure the olfaction ability in each nostril. We appreciate the efforts made to preserve olfaction by Simal et al, and we confirm the anatomic landmarks described to maximally preserve the olfactory mucosa. The technical descriptions made to preserve olfaction need, however, to be confirmed in a study. We are looking forward to reading their results and, of course, offer our support and collaboration in a potential future study. Disclosure The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.