The relationship between sphenoidal sinus and sella turcica morphometry in the Turkish population: a retrospective study.

PURPOSE: The anatomical position of the sphenoidal sinus (SS) is very important for neurosurgeons because of the transsphenoidal approach to the pituitary gland. Therefore, the aim of this study was to determine the volume and shape of the SS and its relationship with the morphometry of the sella turcica. METHODS: This study included CT images of 282 males and 258 females with a mean age of 50.52 years (range 18-75) who underwent head CT. The morphometric values of the sella turcica and the volume of the SS were measured on the included radiologic images. Measurements were made on the sagittal slice closest to the midline in T1 sequence. Morphometric measurements were made with Micro Dicom Viewers software program and volume measurements were made with ITK SNAP software program. RESULTS: In this study, 4 types of SS shapes were obtained in the whole population: amorphous, pentagonal, triangular and quadrilateral. The mean SS volume was 7055.88 mm3 in males and 5694.48 mm3 in females and a statistically significant difference was observed (p < 0.001). In addition, a statistically significant difference was found between the sexes in the width and surface area parameters of the sella turcica (p < 0.05). CONCLUSION: In this study, the morphometric relationship between the shape of the sinus sphenoidale and sella turcica was demonstrated between men and women. In particular, the shape of the sinus sphenoidale was found to be anthropometrically different between men and women in the Turkish population. It is hypothesised that the data obtained in our study will guide surgeons performing transsphenoidal approach.

Endonasal Endoscopic Anatomy of the Orbito-Cavernous-Pterygopalatine Interface: Multilayer Anatomical Description and Landmarks to Define the Limits of the Compartments.

BACKGROUND: Despite growing interest in the endoscopic endonasal approach (EEA) to the medial orbital apex (OA), a comprehensive description of the multilayer topology lying at the intersection of the regional compartments is missing. METHODS: An EEA to the OA, pterygopalatine fossa, and cavernous sinus was performed in 20 specimens. A 360° layer-by-layer dissection was performed taking into consideration relevant anatomical aspects of the interface and documented with 3-dimensional technologies. Endoscopic landmarks were analyzed to provide an outline of the compartments and identify critical structures. Additionally, the consistency of a previously described reference called orbital apex convergence prominence was analyzed and a method to identify its position was introduced. RESULTS: The orbital apex convergence prominence was an inconsistent finding (15%). However, a craniometric method introduced in this study proved to be reliable to reach the orbital apex convergence point. Additional structures such as the sphenoethmoidal suture and a 3-suture junction (sphenoethmoidal-palatoethmoidal-palatosphenoidal) helped to identify the posterior limit of the OA and define a keyhole to access the compartments of the interface. We defined the bone limits of the "optic risk zone," an area where the optic nerve is more susceptible to damage. Furthermore, an orbital fusion line (periorbita-dura-periosteum) was identified and divided into 4 segments according to adjacent structures: optic, cavernous, pterygopalatine, and infraorbital. CONCLUSIONS: Understanding cranial landmarks and the folds of the layers covering the orbito-cavernous-pterygopalatine interface can facilitate tailoring an EEA to the medial orbital space and avoid unnecessary exposure of sensitive anatomy in the vicinity.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma.

PURPOSE: Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature. METHODS: Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature. RESULTS: Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months. CONCLUSION: IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

A Study of the Anatomy of the Eustachian Tube for Its Surgical Approach in Otorhinolaryngology.

BACKGROUND: The eustachian tube (ET) is a connection between the nasopharynx and the middle ear behind the inferior nasal concha. It plays an important role in regulating air pressure across the tympanic membrane for proper transmission of sound. The pharyngeal opening of the tube is an important landmark for endoscopic evaluation in patients suffering from chronic otitis media and is also an important anatomical landmark for the transnasal approach to the infratemporal fossa. Hence, the study was done to locate the position of the pharyngeal opening of the ET in relation to various important anatomical landmarks. METHODOLOGY: Hundred (50 right and 50 left sides) adult (60-80 years) formalin-fixed sagittal sections of head and neck specimens were taken for the study, which was obtained during the undergraduate teaching program. The shape, size, and position of the pharyngeal opening of the ET were noted. The distance between the pharyngeal opening of the ET and various anatomical landmarks was measured with the help of the digital Vernier caliper. The mean and standard deviation of all the parameters were calculated and tabulated. RESULTS: In the present study, a slit-like shape was the most common shape of the pharyngeal opening, present in 62 out of 100 specimens. The difference between the anteroposterior length and vertical height of the two sides showed a statistically significant difference. CONCLUSION: The present study will help to locate the position of the pharyngeal opening of the ET during otorhinolaryngological evaluation for performing various surgeries in the middle ear.

A Case Report of Inflammatory Myofibroblastic Tumor of the Sphenoidal Sinus.

Inflammatory myofibroblastic tumor (IMT) is a tumor composed of differentiated myofibroblastic spindle-shaped cells. It occurs in the soft tissues of the abdomen and lungs, and is very rare in the sphenoid sinus. The diagnosis depends on histopathology and immunohistochemistry, and is easily misdiagnosed. Although metastasis is rare, the recurrence rate is high. Surgical resection is the treatment of choice, and where complete resection is difficult, radiation therapy, hormonal therapy, or molecular targeted drug therapy can be administered. We report a rare case of IMT with a primary origin in the sphenoid sinus, which was entirely resected by nasal endoscopy and confirmed by histological examination.

Combined rare anatomic variants: persistent primitive olfactory artery and azygos pericallosal artery.

The persisting primitive olfactory artery (PPOA) is a rare anatomic variation of the anterior cerebral artery (ACA), being encountered in less than 1% of cases. Different morphological types were reported previously. In type 3, only once reported previously, the PPOA gives off two branches, a nasal one which courses in the olfactory sulcus to supply the territory of the anterior ethmoidal artery, and the callosomarginal artery. It is reported here a combination of rare anatomic variants found in a 71-year-old male patient investigated by computed tomography angiography. A left PPOA left the A1 segment of the ACA and was classified as subtype 3b, as its branches were the nasal one and a frontal trunk, not the callosomarginal artery. That PPOA had a characteristic hairpin turn applied on the anterior fossa floor. The ACA continued as azygos pericallosal artery, which is also a rare finding. As the nasal branch of the PPOA and its hairpin turn is closely related to the anterior fossa floor, such variant should be carefully documented when combined approaches of the skull base are planned by rhinologists and neurosurgeons.

Morphometric assessment of important landmarks on skull intended for Vidian nerve surgery.

PURPOSE: The aim of our study was to determine guide parameters for clinicians by morphometric assessment of important landmarks on cranium intended for Vidian nerve surgery. METHODS: For the study, 23 half-skull bases, 40 skull bases and 40 skulls were obtained from the Department of Anatomy, Ege University Medicine Faculty. The vertical distances were measured using a digital caliper to the nearest 0.01 mm. RESULTS: The anterior opening of the Vidian canal (pterygoid canal) was observed as oval shaped on 57 specimens (31.1%), funnel shaped on 58 specimens (31.7%), round shaped on 64 specimens (35%) and septated on 4 specimens (2.2%). Vidian canal was embedded into the body of sphenoid on 55 specimens (52.4%) (embedded type) and protruded to sphenoidal sinus on 50 specimens (47.6%) (protruded type). 21 specimens of 50 were partial and 29 specimens were total. There were dehiscences on 21 specimens of 50 protruded type on the base of sphenoidal sinus (20%). Anterior opening of the Vidian canal was assessed according to medial lamina of pterygoid process. It was located medially in 169 of the specimens (92.3%) and laterally in 14 specimens (7.7%). CONCLUSION: Vidian canal and Vidian nerve are deeply located structures on skull. Vidian canal and surrounding structures are important landmarks for microsurgery and endoscopic approaches to Vidian nerve. We consider that knowledge of anatomical features of Vidian canal and preoperative imaging by CT (computed tomography) will be supportive when choosing and planning a safe surgical approach.

Automatic forensic identification using 3D sphenoid sinus segmentation and deep characterization.

Recent clinical research studies in forensic identification have highlighted the interest in sphenoid sinus anatomical characterization. Their pneumatization, well known as extremely variable in degrees and directions, could contribute to the radiologic identification, especially if dental records, fingerPrints, or DNA samples are not available. In this paper, we present a new approach for automatic person identification based on sphenoid sinus features extracted from computed tomography (CT) images of the skull. First, we present a new approach for fully automatic 3D reconstruction of the sphenoid hemisinuses which combines the fuzzy c-means method and mathematical morphology operations to detect and segment the object of interest. Second, deep shape features are extracted from both hemisinuses using a dilated residual version of a stacked convolutional auto-encoder. The obtained binary segmentation masks are thus hierarchically mapped into a compact and low-dimensional space preserving their semantic similarity. We finally employ the ℓ2 distance to recognize the sphenoid sinus and therefore identify the person. This novel sphenoid sinus recognition method obtained 100% of identification accuracy when applied on a dataset composed of 85 CT scans stemming from 72 individuals. Automatic Forensic Identification using 3D Sphenoid Sinus Segmentation and Deep Characterization from Dilated Residual Auto-Encoders.

Scedosporium apiospermum invasive sinusitis presenting as extradural abscess.

INTRODUCTION: Chronic invasive fungal rhinosinusitis (CIFR) is a rare entity generally observed in immunodepressed subjects. The pathogen most frequently identified is Aspergillus spp. Imaging generally reveals invasive pseudoneoplastic features. We report a case of Scedosporium apiospermum (S. apiospermum) CIFR with an atypical clinical and radiological presentation. CASE REPORT: A 72-year-old immunocompetent man presented with chronic headache, neck pain and bilateral limitation of lateral gaze. Imaging revealed an isolated left sphenoidal lesion with marked bone changes and an extradural abscess over the clivus. Large endoscopic sphenoidotomy with type II rhinopharyngectomy was performed and the diagnosis of S. apiospermum CIFR was based on histological examination and fungal culture. The patient refused all medical treatment and did not present any signs of recurrence after 1 year of follow-up. DISCUSSION: S. apiospermum is a fungal species rarely isolated in CIFR. The present case was revealed by an atypical clinical presentation including isolated sphenoidal infection complicated by bilateral abducens nerve paralysis and extradural abscess. Imaging was also unusual, revealing features of fibrous dysplasia or bacterial osteomyelitis rather than the typical pseudoneoplastic appearance. The patient was successfully treated by surgery alone, which may therefore be sufficient treatment in immunocompetent subjects.

The septation of the sphenoidal air sinus: a cadaveric study / Septación del seno esfenoidal: investigación cadavérica

The purpose of this study was to investigate the sphenoidal sinus septation in a select South African population, and document the relation of the number and location of the septa to the structures intimately related to the sinus. The intersinus and intrasinus septa of the sinus, the number and attachments of the septa were recorded from forty five cadaveric head specimens. The sphenoidal sinus intersinus septa were recorded as follows: Type 0 (absent septum) in 7.5 %, Type 1 (single septum) in 65 % and Type 2 (double septa) in 22.5 % of cases. The incidence of intersinus septa deviating to the left was prevalent; hence, the right sphenoidal sinus was dominant. The occurrence of intrasinus septa was observed in 93.3 % of cases, with a higher prevalence in males. The intrasinus septa formed cave like chambers on the sinus walls in 65.6 % cases. Incidences of the intersinus septa attaching to sella turcica (ST) (46.25 %) were prevalent compared to cases where they attached to the internal carotid artery (ICA) (6.25 %), maxillary (MN) (1.25 %) and vidian (VN) (1.25 %) nerves. However, the intrasinus septa attached more to the ICA (52.63 %) compared to their attachment to the other neurovascular structures (ST - 26.32 %; MN - 5.36 % and VN - 2.63 %). Surgeons need to be aware of the complex anatomical variations of the sphenoidal sinus septation when performing endoscopic endonasal transsphenoidal surgeries.

El propósito de este estudio fue investigar la septación del seno esfenoidal en una población sudafricana y documentar la relación del número y la ubicación de los septos en relación a las estructuras íntimamente relacionadas con el seno. Los septos interseno e intraseno del seno, el número y las uniones de los septos se registraron a partir de cuarenta y cinco cadáveres. El septo interseno del seno esfenoidal se registró de la siguiente manera: Tipo 0 (tabique/septo ausente) en el 7,5 %, Tipo 1 (tabique/septo único) en el 65 % y Tipo 2 (tabiques/septos dobles) en el 22,5 % de los casos. La incidencia de septos intersenos desviados hacia la izquierda fue prevalente. Por lo tanto, el seno esfenoidal derecho fue dominante. La ocurrencia de septo intraseno se observó en el 93,3 % de los casos, con una mayor prevalencia en varones. Los septos intrasenos formaron cámaras, como cuevas, en las paredes del seno en un 65,6 % de los casos. La incidencia de septos intersenos que se adhieren a la silla turca (ST) (46,25 %) fueron prevalentes en comparación con los casos en que se unieron a la arteria carótida interna (ACI) (6,25 %), al nervio maxilar (NM) (1,25 %) y nervio vidiano (NV) (1.25%). Sin embargo, los septos intersenos se adhirieron más a la ACI (52,63 %) en comparación con su unión a otras estructuras neurovasculares (ST - 26,32 %; NM -5,36 % y NV - 2,63 %). Los cirujanos deben ser conscientes de las complejas variaciones anatómicas de la tabicación del seno esfenoidal cuando se realizan cirugías transesfenoideas endonasales endoscópicas.

Fístula Liquórica Esfenoidal Espontânea ­ relato de caso / Spontaneous sphenoidal liquor fistula - Case report

Introdução: fístula liquórica rinogênica é uma comunicação do espaço subaracnóideo com a fossa nasal ou seios paranasais, decorrentes a um defeito anatômico da dura-máter, osso e mucosa. As fístulas liquóricas nasais espontâneas são eventos raros, cerca de 3%, com possíveis complicações deletérias e uma causa definida. Relato de caso: o caso relatado é de paciente de 47 anos, com queixa de cefaleia de forte intensidade, diagnosticado com fístula liquórica esfenoidal espontânea. Conclusão: o otorrinolaringologista tem importante papel em realizar o diagnóstico e assistir o paciente com fístula liquórica rinogênica.

Introduction: rhinoid cerebrospinal fluid fistula is a communication of the subarachnoid space with the nasal fossa or paranasal sinuses, due to an anatomical defect of the dura mater, bone and mucosa. Spontaneous nasal fluid fistulas are rare events, about 3%, with possible deleterious complications and a definite cause. Case report: the case reported is a 47-year-old patient complaining of severe headache, diagnosed with spontaneous sphenoidal cerebrospinal fluid fistula. Conclusion: has an important role in the diagnosis and assistance of cases with rhinoid cerebrospinal fluid fistula.

Is Complex Sphenoidal Sinus Anatomy a Contraindication to a Transsphenoidal Approach for Resection of Sellar Lesions? Case Series and Review of the Literature.

BACKGROUND: The transsphenoidal approach is considered the gold standard for resection of pituitary adenomas and other sellar region lesions. This approach is guided by a few fundamental anatomic landmarks that conduct the surgeon toward the sellar floor. Some anatomic structures may vary a lot (e.g., intrasphenoidal septa, intercarotid distance) and may be difficult to identify. Pneumatization and conformation of the sphenoidal sinus (SS) plays a key role in accessing the floor of the sella and other skull base structures. A poorly pneumatized SS may be a relative contraindication to the transsphenoidal approach. We analyzed outcome and complications in transsphenoidal surgery for sellar lesions with a difficult SS. METHODS: We analyzed 243 consecutive patients who underwent a transsphenoidal approach for sellar lesions. Patients with poor pneumatization of the SS were included. Neurosurgical and endocrinologic outcomes were reported. RESULTS: Successful treatment using a transsphenoidal approach with neuronavigation and Doppler ultrasound was achieved in 15 patients with a low degree of pneumatization of the SS. A pituitary adenoma was present in 13 of 15 patients. Endocrinologic and neurosurgical outcomes were similar to patients with normal pneumatization of the SS, showing a cure of disease in 6 of 9 patients with functioning adenomas and an improvement of symptoms in cases of nonfunctioning adenomas. CONCLUSIONS: Patients with a poorly pneumatized SS can be treated safely with a transsphenoidal approach using image guidance techniques to avoid major neurovascular complications.

[Arachnoid cyst of the sphenoidal sinus: differential diagnosis of mucocele]. / Kyste arachnoïdien du sinus sphénoïdal: diagnostic différentiel d'une mucocèle.

We here report the case of a 45 year old patient, with no previous history of head injury, presenting with isolated intermittent headache which had evolved since the young age. Clinical examination was normal. Cerebral CT scan showed osteolytic expansive hypodense lesion of the sphenoidal sinus extending inferiorly into the infratemporal fossa and superiorly into the temporal fossa (A). This mass wasn't contrast enhanced. A mucocele was suspected. MRI was performed which showed that the mass had the same enhancement as the cerebrospinal fluid (CSF) and was in continuity with the temporal meninx, without modification in the cerebral parenchyma (B, C). The diagnosis of arachnoid cyst was retained. Given the extension of the cyst and the absence of nerve paralysis, therapeutic abstention as well as clinical and radiological monitoring were performed. Cystic lesions expanding from the sphenoid sinus are relatively rare and can cause non-specific symptoms. Even though these lesions are very rare they should be suspected. Quite often, diagnosis can be determined by CT scan data associated with MRI with diffusion-weighted sequence data, allowing the differential diagnosis of other injuries, in particular mucocele.

Anatomic variation in the pterygopalatine angle of the maxillary sinus and the maxillary bulla.

Bulges of the most posterior ethmoid air cells into the maxillary sinus were termed maxillary bullæ by Onodi. With few exceptions, they have since been ignored by anatomists through time. Likewise, Sieur cells-the spheno-ethmoido-maxillary air cells-are uncommonly found in anatomical texts. We therefore aimed to perform a retrospective cone beam computed tomography study on 50 patients to document the possibilities of anatomic variation in the situs of the orbital process of palatine bone-a variation related anatomically with the pterygopalatine fossa (PPF) and the respective angle of the maxillary sinus. Commonly occurring pneumatizations in this situs were the Sieur cell (58 %/64 % right/left side), and the maxillary recess of the sphenoidal sinus (20 %/22 % right/left side). Alone or in combination, these determined, but not exclusively, the maxillary bullæ. Uncommon pneumatizations in the anterior wall of the PPF were also found, such as a sphenoidal recess of the maxillary sinus, and lateral (maxillary, or pterygopalatine) recesses of the middle and superior, respectively, nasal meatuses. In two different cases, non-Haller, and non-Sieur posterior ethmoid air cells were found extruded posterior to the maxillary sinus. Significant statistical association indicated bilateral symmetry of Sieur's cell and of the maxillary recess of the sphenoidal sinus. It is important to identify such variant pneumatizations on a case-by-case basis in different surgical procedures and endoscopic corridors.

Traumatic intra-sphenoidal pseudoaneurysm lodged inside the fractured sphenoidal sinus.

We describe a case of traumatic intra-sphenoidal right internal carotid artery pseudoaneurysm lodged inside the fractured sphenoidal sinus that developed in a patient with a previous history of frontal and skull base fractures involving the sphenoid sinus and walls of the carotid canal, but with normal intracranial findings at early CT angiography. The patient presented two episodes of massive life-threatening delayed epistaxis before successful endovascular treatment combining the use of coils and an uncovered stent was instituted. This case report highlights that patients with head trauma who present sphenoid sinus fractures with or without massive epistaxis should be evaluated for the development of traumatic internal carotid artery pseudoaneurysm as soon as possible. If the first angiographic evaluation reveals normal findings, repeated epistaxis should prompt a second angiographic evaluation because psudoaneurysm takes time to develop. Early treatment with uncovered stent of the aneurysm can be a life-saving therapeutic approach.

Meningocele and Meningoencephalocele of the Lateral Wall of Sphenoidal Sinus: The Role of the Endoscopic Endonasal Surgery.

BACKGROUND: Meningocele and meningoencephalocele of the lateral wall of the sphenoidal sinus (LWSS) are rare lesions, crossing the borders of multiple disciplines such as ear-nose-throat, maxillofacial, and neurologic surgery. We reviewed our surgical experience to analyze the role of the endoscopic endonasal approach and consider these pathologies from different perspectives. METHODS: All consecutive cases of meningocele and meningoencephalocele of LWSS operated through an endoscopic endonasal approach from 1998 to 2015 in our institutions were collected. Medical history, focusing on previous episodes of cerebrospinal fluid leak, meningitis or seizures, was considered. The outcome was assessed considering the medical condition and the postoperative neuroimaging. RESULTS: The series includes 23 patients (7 male, 16 female). Mean age was 52 years (26-73 years). Eleven cases were meningoencephaloceles and 12 meningoceles. A clear cerebrospinal fluid leak occurred on in 19 patients and was associated with meningitis in 3. Two were presenting a history of epilepsy. No complications were observed, but 1 case presented seizures on waking. At follow-up (mean 84 months, 4-167) each patient is in good clinical condition with no further episodes of leaking or seizures. CONCLUSIONS: Endoscopic endonasal surgery is a safe and effective approach for meningocele and meningoencephalocele of LWSS; it allows resection of herniated tissue and repair of the osteodural defect. The favorable clinical outcome and the possible effectiveness on seizures lead us to support this approach as first minimally invasive treatment also in presence of epilepsy, as a first low risk epilepsy surgical procedure.

Anatomía radiológica del seno esfenoidal: análisis en 120 pacientes intervenidos / Radiologic anatomy of sphenoidal sinus, analysis of 120 surgically intervened patients

Introducción: La patología tumoral hipofisiaria es una consulta frecuente en Neurocirugía. La vía de abordaje a elegir preferentemente es transesfenoidal. Por esto, es de suma importancia conocer la anatomía de los senos paranasales cuando se planifica este abordaje. Materiales y Métodos: Se describe la anatomía radiológica de estudios por Tomografía Computada (TC) y Resonancia Magnética (RM) de 120 pacientes con diagnóstico de adenoma hipofisiario, que se sometieron a cirugía transesfenoidal de hipófisis, prestando especial interés en la morfología de las cavidades paranasales esfenoidales. Resultados: Tipo de neumatización: preselar 25 por ciento y postselar 75 por ciento; Septos: simples 45 por ciento y múltiples 55 por ciento; diámetros promedio: antero-posterior 2,3 cm, transverso: 3,3 cm y vertical: 2,25 cm. Los Senos esfenoidales con neumatización postselar tienen un diámetro anteroposterior significativamente mayor (P < 0,005) que los preselares. Los senos esfenoidales con septo simple tienen un diámetro transverso significativamente mayor (P < 0,007) que los con múltiples septos. El 50 por ciento de los septos siguen una trayectoria paramediana, y el 50 por ciento se desvía hacia una de las arterias carótidas. Conclusión: se confirma la gran variación anatómica del seno esfenoidal siendo independiente del sexo del paciente, además hemos constatado que la relación establecida por los septos intraselares con elementos vasculares intracraneales es muy variable, siendo este hallazgo de suma importancia en la planificación preoperatoria. Los hallazgos realizados por Tomografía computada (TC), pueden ser homologables a lo descrito por otros autores en disecciones cadavéricas.

Introduction: The pituitary tumor pathology is a common query in Neurosurgery. The choice of approach is transsphenoidal preferably, so it is extremely important to know the anatomy of the sinuses when planning this approach. Materials and Methods: We describe the radiological anatomy studies Computerized tomography (CT) and Magnetic Resonance (MR) of 120 patients with pituitary adenoma who underwent transsphenoidal pituitary surgery, with special attention to the morphology of the sphenoid sinuses. Results: Neumatization type: pre-sellar 25 percent and 75 percent post-sellar; Septa: Single 45 percent, multiple 55 percent, mean diameters: 2.3 cm anteroposterior, transverse: 3.3 cm and vertical: 2.25 cm. The sphenoid sinuses with postsellar neumatization have anteroposterior diameter significantly higher (P < 0.005) than the pre-sellar. The sphenoid sinuses are single septum transverse diameter significantly higher (P < 0.007) than those with multiple septa. The 50 percent of the septa paramedian follow a path, and 50 percent is diverted to one of the carotid arteries. Conclusion: Results support the large sphenoid sinus anatomical variation is independent of patient sex, and we found that the relationship established by the intrasellar septa with intracranial vascular elements is very variable, this finding being paramount in preoperative planning. The findings by computed tomography (CT) may be comparable to that described by other authors in cadaveric dissections.