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The developing sphenoid is regarded as a median cartilage mass (basisphenoid [BS]) with three cartilaginous processes (orbitosphenoid [OS], ala temporalis [AT], and alar process [AP]). The relationships of this initial configuration with the adult morphology are difficult to determine because of extensive membranous ossification along the cartilaginous elements. The purpose of this study was therefore to evaluate the anatomical connections between each element of the fetal sphenoid and adult morphology. Sagittal sections from 25 embryos and fetuses of gestational age 6-34 weeks and crown-rump length 12-295 mm were therefore examined and compared with horizontal and frontal sections from the other 25 late-term fetuses (217-340 mm). The OS was identified as a set of three mutually attached cartilage bars in early fetuses. At all stages, the OS-post was continuous with the anterolateral part of the BS. The BS included the notochord and Rathke's pouch remnant in embryos and early fetuses. The dorsum sellae was absent from embryos, but it protruded from the BS in early fetuses before a fossa for the hypophysis became evident. Although not higher than the hypophysis at midterm, the dorsum sellae elongated superiorly after gestational age 25 weeks. In early fetuses, the AP was located on the side immediately anterior to the otic capsule. The AT developed on the side immediately posterior to the extraocular rectus muscles. At late term, the greater wing was formed by membranous bones from the AT and AP. The AT and AP formed a complex bridge between the BS and the greater wing. A small cartilage, future medial pterygoid process (PTmed) was located inferior to the AT in early fetuses. At midterm, one endochondral bone and multiple membranous bones formed the PTmed. The lateral pterygoid process (PTlat) was formed by a single membranous bone plate. Therefore, we connected fetal elements and the adult morphology as follows. (1) Derivative of the OS makes not only the lesser wing but also the anterior margin of the body of the sphenoid. (2) Derivatives of the BS are the body of the sphenoid including the sella turcica and the dorsum sellae. (3) Most of the greater wing including the foramen rotundum and the foramen oval originate from the AT and AP and multiple membranous bones. (4) The PTmed originate from endochondral bones and multiple membranous bones, while the PTlat derive from a single membranous bone.

BACKGROUND: Tuberculum sellae meningiomas are deep-seated tumors difficult to access, located in close relation with important neurovascular structures. While the transsphenoidal approach is linked to specific complications, the different reported transcranial approaches are associated with advantages and drawbacks due to the respective angle of attack, with some areas adequately exposed and others partially hidden. METHOD: We report the technical aspects of the anterior interhemispheric approach we practice. CONCLUSION: This approach has the advantage of providing full control over all the vasculo-nervous structures involved and of allowing access to the medial aspect of both optic canals tangentially to the dorsum sellae.

BACKGROUND Geometric morphometric analysis with Procrustes superimposition is an advanced computational tool that can be used to quantify dynamic changes in complex three-dimensional structures. The present study couples high resolution CT imaging with a Geometric Morphometric approach in order to further understand the complex dysmorphology that occurs in unilateral coronal synostosis (UCS). METHODS Forty-one UCS patients and 41 age- and sex-matched controls received high-resolution CT imaging. Thirty-one anatomical landmarks were identified on each imaging set. A geometric morphometric workflow was used to perform a Procrustes superimposition to register landmarks into a common space. Procrustes-aligned landmarks were used to derive angle calculations, lengths, and other anatomical measurements. Three-dimensional coordinates were also used to perform a principal components analysis (PCA). RESULTS Unilateral coronal synostosis patients exhibited significant angular deviation at the levels of the inferior skull base, mid-posterior fossa, and vertex. Both left- and right-sided UCS patients showed increased lengthening in the transverse (left-right) dimension, exhibiting increased length between the left and right EAC (P = 0.047). Conversely, UCS patients revealed shortening in the midline AP dimension as evidenced by the decreased Nasal root-Lambda (P

The pretemporal transcavernous approach (PTA) provides optimal exposure and access to the basilar artery (BA); however, the PTA can be invasive when vital neurovascular structures are mobilized. The goal of this study was to evaluate mobilization strategies to tailor approaches to the BA. After an orbitozygomatic craniotomy, 10 sides of 5 cadaveric heads were used to assess the surgical access to the BA via the opticocarotid triangle (OCT), carotid-oculomotor triangle (COT), and oculomotor-tentorial triangle (OTT). Measurements were obtained, and morphometric analyses were performed for natural neurovascular positions and after each stepwise expansion maneuver. An imaginary line connecting the midpoints of the limbus sphenoidale and dorsum sellae was used as a reference to normalize the measurements of BA exposure and to facilitate the clinical applicability of this technique. In the OCT, the exposed BA segment ranged from − 1 ± 3.9 to + 6 ± 2.0 mm in length in its natural position. In the COT, the accessible BA segment ranged from − 4 ± 2.3 to − 2 ± 3.0 mm in length in its natural position. Via the OTT, the accessible BA segment ranged from − 7 ± 2.6 to − 5 ± 2.8 mm in length in its natural position. In the OCT, COT, and OTT, a posterior clinoidectomy extended the exposure down to − 6 ± 2.7, − 8 ± 2.5, and − 9 ± 2.9 mm, respectively. This study quantitatively evaluated the need for the expansion maneuvers in the PTA to reach BA aneurysms according to the patient’s anatomical characteristics.

The aim of this work was to determine reliable anatomical landmarks for locating and preserving the abducens nerves (6th cranial nerves) during trans-facial or trans-nasal endoscopic approaches of skull base tumors involving the clivus and the petrous apex. In order to describe this specific anatomy, we carefully dissected 10 cadaveric heads under optic magnification. Several measurements were taken between the two petro-sphénoidal foramina, from the bottom of the sella and the dorsum sellae. The close relationship between the nerves and the internal carotid artery were taken into account. We defined a trapezoid area that allowed drilling the clivus safely, preserving the 6th cranial nerve while being attentive to the internal carotid artery. The caudal part of this trapezium is, on average, 20 mm long at mi-distance between the two petro-sphenoidal foramina. The cranial part is at the sella level, a line between both paraclival internal carotid arteries. Oblique lateral edges between the cranial and caudal parts completed the trapezium.

BackgroundSkull base chordomas (SBCs) are rare malignant bone tumors with dismal long-term local control. Endoscopic endonasal surgeries (EESs) are increasingly adopted to resect SBCs recently. Gross total resection (GTR) favors good outcomes. However, the SBCs often invade the skull base extensively and hide behind vital neurovascular structures; the tumors were challenging to remove entirely. To improve the GTR, we established a surgical strategy for EES according to the tumor growth directions.MethodsA total of 112 patients with SBCs from 2018 to 2019 were classified into the derivation group. We retrospectively analyzed their radiologic images and operation videos to find the accurate tumor locations. By doing so, we confirmed the tumor growth directions and established a surgical strategy. Fifty-five patients who were operated on in 2020 were regarded as the validation group, and we performed their operations following the surgical strategy to verify its value.ResultsIn the derivation group, 78.6% of SBCs invade the dorsum sellae and posterior clinoid process region. 62.5% and 69.6% of tumors extend to the left and right posterior spaces of cavernous ICA, respectively. 59.8% and 61.6% of tumors extend to the left and right posterior spaces of paraclival and lacerum ICA (pc-la ICA), respectively. 30.4% and 28.6% of tumors extended along the left and right petroclival fissures that extend toward the jugular foramen, respectively. 30.4% of tumors involved the foramen magnum and craniocervical junction region. The GTR was achieved in 60.8% of patients with primary SBCs in the derivation group. Based on the tumors’ growth pattern, pituitary transposition and posterior clinoidectomy techniques were adopted to resect tumors that hid behind cavernous ICA. Paraclival ICA transposition was used when the tumor invaded the posterior spaces of pc-la ICA. Lacerum fibrocartilage resection and eustachian tube transposition may be warranted to resect the tumors that extended to the jugular foramen. GTR was achieved in 75.0% of patients with primary SBCs in the validation group.ConclusionBesides the midline clival region, the SBCs frequently grow into the eight spaces mentioned above. The surgical strategy based on the growth pattern contributes to increasing the GTR rate.

A sellar spine is a midline bony spur arising from the ventral aspect of the dorsum sellae. Representing a remnant of the anterior notochord, it is often an incidental finding and thought to be of no clinical significance. However, it has recently been suggested that a potential association may exist between sellar spine and pediatric pituitary endocrinopathies, possibly caused by deformation of the developing pituitary gland by the sellar spine. To our knowledge, this is the first case report demonstrating an association between sellar spine and clinical diabetes insipidus.

Background: The bridging of sella turcica and dental anomalies have common embryonic origins and underlying genetic basis. Many studies have linked sella turcica bridging to developmental syndromes affecting the craniofacial region, and local dental anomalies. The purpose of this study was to determine the association between the bridging of the sella turcica and hypodontia. Methods: The clinical records along with lateral cephalograms and orthopantamograms of 40 hypodontic patients as study sample (12 males and 28 females; mean age 13.9±2.5 years) and of 120 non-hypodontic patients as control groups (58 males and 62 females; mean age 14.1±1.8 years) matched for age and gender to the study sample who came for orthodontic treatment, were collected from orthodontic clinics. Panoramic radiographs were evaluated for hypodontia. In order to quantify the extent of a sella turcica bridge on lateral cephalogram, the contour of the pituitary fossa from the tip of the dorsum sellae to the tuberculum sella was traced and extent of bridging was categorized by standardize scoring scale using the comparative measurement of sella length and diameter. Results: The presence of complete bridging (17.5%) and partial bridging (55%) in patients with hypodontia were more than complete bridging (5%) and partial bridging (37.5%) in patients without hypodontia (controls). The association between the degree of bridging and hypodontia was statistically significant according to chi-square statistics (p=0.001). There were no statistical differences between the degree of calcification and gender (p=0.616). Conclusions: The prevalence of sella turcica bridging inpatient with hypodontia was more and showed a significant association between sella turcica bridging and hypodontia. There is no dependence between the degree of calcification and gender. As the sella turcica bridge appears early in life, it should alert clinicians as a useful diagnostic predictor to the possible development of tooth anomalies later in life.

Background The primitive trigeminal artery (PTA) is the most common and the largest persistent carotid-basilar anastomosis. Primitive trigeminal artery variants (PTAVs) are anastomoses between the internal carotid artery and cerebellar arteries. These vessels pose a risk of hemorrhagic or ischemic complications during neurosurgical procedures in the parasellar and intrasellar regions. The aim of this study was to determine the prevalence of both PTA and PTAVs and their clinically important anatomic features. Methods Major electronic databases were thoroughly searched for studies on PTA and PTAV. References in the included articles were also evaluated. Data regarding prevalence, laterality, origin, course patterns, and associated anomalies were extracted and pooled into a meta-analysis. Results A total of 39 studies (110,866 patients) were included in the meta-analysis. The total pooled prevalence estimate of PTA and PTAVs combined was 0.4% (95% confidence interval [CI], 0.3–0.5). Individually, PTA was present in 0.3% of patients and PTAV in 0.2%. Both arteries most often originated from the C4 internal carotid artery and took a course lateral to the dorsum sellae. The anterior inferior cerebellar artery type was the predominant PTAV (72.1%). Basilar artery hypoplasia was found in 42.5% of patients with a PTA. Conclusions PTA and PTAVs are rare vessels, but they are clinically important because they can contribute to trigeminal neuralgia. Knowledge of the potential course of these arteries is essential in neuroradiology and neurosurgery, especially in minimally invasive procedures such as the endoscopic endonasal transsphenoidal approach to the pituitary gland and the percutaneous gasserian ganglion procedure.

In the literature, there is a lack of complete description of dural arteries of the dorsoclival area with contradictory data. However, dorsoclival area is a site of tumors and vascular malformation or the skull base. That is why, the knowledge of dural arteries is very important. Using a colored silicone mix preparation, fifteen sides of eight cranial bases were studied using 4–20× magnification of the surgical microscope. Dorsoclival area is supplying by three arterial complexes, internal carotid artery complex with always the dorsal meningeal artery for the superior two-third of the clivus, medial clival artery for the dorsum sellae, the external carotid artery complex with the hypoglossal and jugular branches of the ascending pharyngeal artery for the inferior one-third of the clivus, and the vertebral artery complex with the anterior meningeal artery for the most inferior part of the clivus and the anterior edge of the foramen magnum. Moreover, there are many anastomoses between those three arterial complexes at this area. Dural arterial supply of the dorsoclival area is very opulent. Its knowledge is important for surgical approaches and endovascular procedures.

OBJECTIVEThe expanded endoscopic endonasal approach (EEA) has shown promising results in treatment of midline skull base lesions. Several case reports exist on the utilization of the EEA for treatment of aneurysms. However, a comparison of this approach with the classic transcranial orbitozygomatic approach to the basilar apex (BAX) region is missing.The present study summarizes the results of a series of cadaveric surgical simulations for assessment of the EEA to the BAX region for aneurysm clipping and its comparison with the transcranial orbitozygomatic approach as one of the most common approaches used to treat BAX aneurysms.METHODSFifteen cadaveric specimens underwent bilateral orbitozygomatic craniotomies as well as an EEA (first without a pituitary transposition [PT] and then with a PT) to expose the BAX. The following variables were measured, recorded, and compared between the orbitozygomatic approach and the EEA: 1) number of perforating arteries counted on bilateral posterior cerebral arteries (PCAs); 2) exposure and clipping lengths of the PCAs, superior cerebellar arteries (SCAs), and proximal basilar artery; and 3) surgical area of exposure in the BAX region.RESULTSExcept for the proximal basilar artery exposure and clipping, the orbitozygomatic approach provided statistically significantly greater values for vascular exposure and control in the BAX region (i.e., exposure and clipping of ipsilateral and contralateral SCAs and PCAs). The EEA with PT was significantly better in exposing and clipping bilateral PCAs compared to EEA without a PT, but not in terms of other measured variables. The surgical area of exposure and PCA perforator counts were not significantly different between the 3 approaches. The EEA provided better exposure and control if the BAX was located ≥ 4 mm inferior to the dorsum sellae.CONCLUSIONSFor BAX aneurysms located in the retrosellar area, PT is usually required to obtain improved exposure and control for the bilateral PCAs. However, the transcranial approach is generally superior to both endoscopic approaches for accessing the BAX region. Considering the superior exposure of the proximal basilar artery obtained with the EEA, it could be a viable option when surgical treatment is considered for a low-lying BAX or mid–basilar trunk aneurysms (≥ 4 mm inferior to dorsum sellae).

Pneumatization variants of the temporal bone have a crucial importance in several surgical interventions. However, very few data are known about possible correlation with other pneumatization variants.Pneumatization of glenoid fossa, petrous apex, and infralabyrinthine portion of temporal bone was assessed in 200 computed tomography scans, equally divided between males and females (18-92 years). Pneumatization variants of the ethmoid (concha bullosa, agger nasi, pneumatized crista galli) and the sphenoid sinuses (pneumatized pterygoid processes, anterior clinoid processes, dorsum sellae, volume) were recorded as well.Differences in prevalence of each pneumatization type according to sex and side, among different portions of the temporal bone, and between temporal bone and the pneumatized variants of the ethmoid bone and sphenoid sinuses, were assessed through chi-square test (P

Objective The retroinfundibular and upper clival regions are challenging to access using the endoscopic endonasal approach because these regions are obstructed by the dorsum sellae and posterior clinoid processes. We evaluated the safety and clinical efficacy of endoscopic dorsum sellar resection (DSR) and identified the optimal indications for endoscopic DSR in patients with craniopharyngioma. Methods A retrospective study was conducted of patients who had undergone treatment with an endoscopic endonasal approach from January 2014 to January 2019. We identified a total of 50 patients who had undergone DSR. The indications for DSR included the following: 1) a tumor involving the upper clivus; 2) a tumor located behind the dorsum sellae; and 3) a tumor involving the interpeduncular or prepontine cistern. We evaluated the clinical outcomes, postoperative endocrinological status, and surgical morbidities. Results Of the 50 patients, 16 had been treated for craniopharyngioma, 30 for chordoma, 2 for pituitary adenoma, 1 for schwannoma, and 1 for chondrosarcoma. An extradural approach for DSR with posterior clinoidectomy was performed in 33 patients (66.0%) and an interdural transcavernous approach in 17 patients (34.0%). The overall gross total tumor resection rate was 92.0% (46 of 50 patients). Postoperatively, 28 of 33 patients (84.8%) with normal pituitary function preoperatively showed preservation of hormonal function postoperatively. Conclusions DSR with or without posterior clinoidectomy is a challenging procedure that requires considerable effort and advanced surgical techniques. However, it can be safely performed with accumulating experience and a thorough knowledge of the surrounding anatomical structures.

This study aimed to investigate the frequency of squamous suture (SqS) obliteration, to estimate the involvement of the major calvarial sutures and those surrounding the temporal squama, and to inspect the neuro- and basicranium for deformities. A series of 211 dry skulls of contemporary adult males were macroscopically observed. The skulls with closed SqS were scanned using an industrial µCT system. Digital morphometry of the skulls with obliterated SqS was performed by recording the 3D coordinates of anatomic landmarks and calculation of linear distances, angles and indices. Obliteration of SqS was observed in 3 (1.42%) skulls. One skull showed bilateral SqS obliteration. The other two cases were unilateral, one right-sided and one left-sided. SqS obliteration seems to be co-ordinated with the closure of the parietomastoid suture, partially related to the closure of the occipitomastoid, sphenoparietal and sphenofrontal sutures, and independent from the closure of the sphenosquamosal suture and the major calvarial sutures. No severe disproportions in the skull configuration were observed in the three investigated cases. The major differences in the complimentary hemicrania concern the parietal and occipital parts of the skull vault. Dorsum sellae erosion, an indicator for raised intracranial pressure, was observed in all three cases.

Current advances in the neurosurgical field and the urge for minimal access approaches encouraged the development of surgical techniques that allowed the treatment of intra and extradural pathologies of the clivus, ventral brainstem, and posterior circulation vessels through the endonasal corridor. The classical endocranial divisions of the clivus have been the upper clivus, between the superior border of the dorsum sellae and the dural pori of the abducens nerve (VI CN); middle clivus, between the latter and the glossopharyngeal meatus of the jugular foramen; and the lower clivus, between the latter and the anterior border of the foramen magnum. A similar classification has been described by using landmarks that are recognizable from the endonasal perspective. A thorough understanding of the clivus anatomy and adjacent structures and a refined microsurgical technique allow the surgeon to treat several pathologies of this region, tailoring the surgical approach accordingly. Further improvements in vascularized reconstruction techniques have been used to diminish the incidence of postoperative cerebrospinal fluid leaks, a previous drawback of the endoscopic endonasal approach. In this chapter, we review the surgical indications, clival anatomy, and technical nuances for the access to the clivus and for skull base reconstruction.

Background In craniosynostosis patients under 3 months of age, suturectomy is a valuable early treatment improving their outcomes. However, conventional suturectomy might not be in severe patients. The efficacy of our developed suturectomy using absorbable plates was examined. Methods Our method was indicated for craniosynostosis patients under 3 months old who had severe intracranial hypertension, scaphocephaly, plagiocephaly, or trigonocephaly between September 2011 and March 2018. All patients underwent suturectomy, and the bone edges on both sides of the cuts were covered with absorbable plates. Evaluation was conducted with 3-dimensional computed tomography and photographs, and cephalic index, distance from dorsum sellae to forehead on computed tomography were analyzed. Results Twenty-one of the 25 patients were evaluated. The preoperative cranial shapes were 4 brachycephaly, 6 scaphocephaly, 5 oxycephaly, 2 clover-leaf deformity, and 4 plagiocephaly. There were 9 syndromic and 12 nonsyndromic patients. The mean age at the time of surgery was 52.3 days (7-89), and the mean follow-up period was 3.5 years (1-8).The cephalic index and cranial definition improved in 18 patients. The secondary surgery was not required in four syndromic and none of the 12 nonsyndromic patients. There were no major complications. Conclusion Placement of absorbable plates was able to prevent bone formation during the early postoperative period, and yet also promote bone formation after plate absorption. The authors believe syndromic craniosynostosis patients with severe deformities and nonsyndromic ones with scaphocephaly or plagiocephaly, successfully avoided secondary surgeries. This approach is less invasive for craniosynostosis and is expected to be highly effective.

The sella turcica is an important anatomical reference used in orthodontics for the evaluation of craniofacial growth. Studies have found variations in the sella turcica morphology in patients with syndromes affecting the craniofacial complex. This review aims to determine whether genetic syndromes involving the craniofacial complex are associated with abnormal radiographic sella turcica morphology and whether there is a pattern of malformation which is consistent within each syndrome. An electronic database search was conducted to identify relevant studies. We included primary studies describing the morphology of the sella turcica on lateral radiographs in human subjects with genetic syndromes involving the craniofacial complex. No restrictions were placed on language or timeframe. PROSPERO registration CRD42019148060. Thirty-eight studies were included in this review. A 'J'-shaped sella was found in patients with Hutchinson-Gilford-Progeria syndrome and other syndromes. A bulbous dorsum sellae was highly prevalent Cleidocranial dysplasia, and a bulbous dorsum sellae and uneven contours of the clivus was found in Cri du chat syndrome. A steep clivus was described in patients with Axenfeld-Rieger syndrome. An oblique anterior wall was the most frequent malformation found in Down's syndrome. Genetic syndromes affecting the craniofacial complex are associated with abnormal morphology of the radiographic sella turcica. Clinicians should be observant of abnormal sella turcica morphology which can be a sign of undiagnosed or subclinical syndromes. More high-quality studies are needed which use standardized and objective methods of determining the morphology of the sella turcica.

Basilar tip aneurysm clipping is technically challenging because of the depth of operative corridor, rarity in presentation, and important perforators supplying deep, critical structures. Two major approaches to basilar tip aneurysms include (1) a frontotemporal (transorbital) trans-sylvian approach for most aneurysms and (2) a modified subtemporal approach for aneurysms with low-lying necks. A 53-yr-old woman presented to our institution with a large unruptured basilar tip aneurysm notable for a low, broad neck (6.4 mm). After discussion of risks and benefits of endovascular vs surgical options, the patient consented to operative intervention. She underwent a right frontotemporal craniotomy with zygomatic osteotomy, intradural petrous apicectomy, elective sectioning of the fourth cranial nerve (CN IV), and intracavernous removal of the dorsum sellae and posterior clinoid process to provide more space for aneurysm dissection. After temporary clipping of the basilar artery, the perforating arteries were dissected free from the aneurysm and the aneurysm occluded with 2 fenestrated clips. Important technical nuances of the approach include (1) achieving ample working room for temporary occlusion aneurysm dissection, (2) careful dissection of the perforators and contralateral P1, and (3) utilization of 2 fenestrated clips to accommodate and preserve the ipsilateral P1 segment. Postoperative angiogram showed complete aneur-ysmal occlusion. Postoperatively, the patient demonstrated mild cognitive impairment and a right CN IV palsy. At 6-wk follow-up, cognition recovered to normalcy. More recently, at 12-mo follow-up, the patient noted intermittent diplopia. Formal neuro-ophthalmologic assessment confirmed persistence of a CN IV palsy treated with prism lenses but no other neurological deficits.

Background The anterior transpetrosal (ATP) approach is the most appropriate approach for petroclival meningiomas (PCMs), which are typically located from the dorsum sellae to the upper border of the internal auditory meatus (IAM). Although neurosurgeons can resect over this area if the tumor is detached from the dura, tumors within the indication area for PCMs are not appropriate for the ATP approach, because it can be difficult to evaluate whether the tumor is attached to or only touching the dura. In this study, we investigated the tumor extension area based on an evaluation of the feeding artery to achieve a more accurate assessment of the dural attachment area. Methods Using various angiography techniques, we studied 51 feeding arteries from 24 patients who had undergone surgical treatment of primary petroapex meningiomas and PCMs via the ATP approach. We measured the lower and posterior extension distances, the extension rate of the cavernous sinus and Meckel's cave, and the midline extension rate of the tumors. Results The ascending pharyngeal artery (AphA) was the predominant feeding artery for tumors with lower extension. We determined that tumors extending over the lower border of IAM in cases in which the feeding artery was not the AphA can be resected using the ATP approach. Conclusions This study shows an association between the predominant feeding artery and tumor extension area and demonstrates that an evaluation of the dural attachment area based on the feeding artery can aid selection of the appropriate surgical approach.

To explore the surgical methods and clinical effect of endoscopic endonasal approaches for the treatment of invasive pituitary adenomas (IPAs).A retrospective analysis was made of the clinical data of 74 patients (75 procedures) with IPAs treated by different endoscopic endonasal approaches at the Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University from May 2014 to August 2017. The data include clinical manifestation, imaging features, surgical methods and complications, resection rate, cure rate, prognosis, and complications in different Knosp classifications and Hardy stages. The transcavernous approach was used in 47 patients, the lateral-cavernous approach was used in 14 patients, the tuberculum sella planum approach was used in 8 patients, and the diaphragma sellae open or dorsum sellae cut approach was used in 6 patients.The gross total resection (GTR) rate was 70.7% (53 patients) and tumor residue rate was 29.3% (22 patients). GTR rate for pituitary adenoma according to Knosp classification was 89.3% in grade 3 and 28.6% in grade 4. The biology cure rate was 75.0% and 23.8%, respectively. There was significance between them (P 0.05). In addition, the GTR rate of Hardy stage was 90.5% in stage C, 90.0% in stage D, 26.1% in stage E, and the biology cure rate was 80.1%, 75.0%, and 13.0%, respectively. There was significance among them (P 0.05) Postoperative severe complications included 9 patients (12.0%) with cerebrospinal fluid leaks, 26 patients (34.7%)with electrolyte imbalance, 36 patients (48.0%) with transient diabetes insipidus, 22 patients (29.3%) with hypopituitarism, 2 patients (2.7%) with permanent hypopituitarism, and 2 patients (2.7%)with epistaxis. The follow-up lasted 2-41 months (average, 19.3 months). No patient experienced recurrence after GTR, 1 patient undergoing subtotal experienced recurrence and underwent reoperation, 3 patients underwent postoperative Gamma Knife treatment, and 2 patients with refractory IPA were given temozolomide and metformin chemotherapy.According to the invasiveness of IPA, choosing the appropriate endoscopic surgical approach is helpful in removing tumors and reducing complications.

The clivus is a bony structure formed by the fusion of the basioccipital and basispheniod bone at the sphenooccipital synchondrosis. This downward sloping structure from the dorsum sellae to the foramen magnum is derived from mesoderm and ectoderm properties. This comprehensive review of the clivus will discuss its basic anatomy, embryology, pathological findings, and surgical implications. The clivus is an endochondral bone, formed under two processes; first, a cartilaginous base is developed, and it is secondly reabsorbed and replaced with bone. Knowledge of its embryological structure and growth of development will clarify the pathogenesis of anatomical variants and pathological findings of the clivus. Understanding the anatomy including proximity to anatomical structures, adjacent neurovasculature properties, and anatomical variants will aid neurosurgeons in their surgical management when treating pathological findings around the clivus.

Computed tomography represents the gold standard for the assessment of morphological characteristics of sphenoid sinuses, whose anatomy has acquired a novel interest because of the recent introduction of transsphenoidal surgery and robot-assisted procedures. One of the most relevant parameters for planning surgical intervention is the volume of sphenoid sinuses, and with time few population studies have been published. However, at present, no data are available concerning the relation between volume and anatomical variants of sphenoid sinuses. We retrospectively evaluated head CT-scans of 100 patients (age range 25–99 years; mean age males 45.0; mean age females 50.5 years) to calculate the volume of sphenoid sinuses through automatic segmentation. Possible statistically significant differences according to sex and variants of pneumatization, and type of sinus were assessed, respectively, through Student’s t test and one-way ANOVA test (p

Background Basilar artery (BA) dolichoectasia has been associated with cerebral small vessel disease (SVD). However, studies have focused on stroke patients, and results cannot be extrapolated to the population at large. In this study, we aimed to assess prevalence of BA dolichoectasia and its association with SVD in community-dwelling older adults living in rural Ecuador. Methods Atahualpa residents aged ≥60 years underwent brain magnetic resonance imaging and magnetic resonance angiography of intracranial vessels. Following Smoker's criteria, the mean BA diameter plus 2 standard deviation defined ectasia. In addition, a location lateral to the lateral margin of the clivus of dorsum sellae or a bifurcation at the third ventricle floor or higher defined dolichosis. Associations between BA abnormalities and imaging markers of SVD were assessed by the use of regression models adjusted for demographics and cardiovascular risk factors. Results Of 346 participants, 11 (3.2%) had ectasia, 40 (11.6%) had dolichosis, and 47 (13.6%) had dolichoectasia (ectasia, dolichosis, or both). BA diameter was only associated with severity of white matter hyperintensities ( P = .038). Dolichosis was associated with deep cerebral microbleeds ( P = .002) but not with white matter hyperintensities. Dolichoectasia was associated with both white matter hyperintensities ( P = .031) and cerebral microbleeds ( P = .001). There were no associations with lacunar infarcts or enlarged perivascular spaces in any model. Conclusions Prevalence of BA dolichoectasia in this rural setting is similar to that reported in other populations. Associations with imaging markers of SVD differ according to whether the subject has ectasia or dolichosis.

Sphenoid bone may be affected by different variants of pneumatisation, which have a relevant importance from a clinical and surgical point of view. The description of such variants in different populations may give useful information. However, few articles describe the variability of sphenoid pneumatised structures and none of them focuses on Northern Italian population. Variants of pneumatisation of sphenoid bone were described in a sample of 300 Northern Italian patients who underwent a CT scan. More than fifty-seven percent of patients showed a form of anatomical variant: the most common form was the pneumatised pterygoid processes (39.6%), followed by dorsum sellae (32.9%) and clinoid processes (20.3%), without statistically significant differences between males and females (p > 0.01). In 26.3% of patients, a combined pneumatisation of these three structures was observed, being the combination pterygoid processes-dorsum sellae the most frequent (11.3%). In 9.3%, all the three sphenoid structures were affected. This article is the first description of the prevalence of different variants of pneumatisation in a Northern Italian population: the occurrence of such forms has to be acknowledged for their possible clinical and surgical consequences.

Surgical treatment of lesions involving the ventral craniovertebral junction (CVJ) and the lower clivus, traditionally involved complex lateral or transoral approaches to the skull base. However, mid or upper clivus involvement requires more extensive lateral approaches. Recently, the endoscopic endonasal approach (EEA) has become the standard for upper CVJ lesions and medial clival, and a valuable alternative for those tumors extending in its upper third as well as laterally. However, the EEA is associated with an increased risk of post-operative CSF leakage and infection when the tumor is characterized by an intradural extension. Furthermore, whenever the tumor has significant lateral and/or inferior extension below the odontoid process, the chances for a complete resection decrease. To analyze the extent of exposure of a hybrid microscopic-endoscopic transcondylar antero-lateral approach to the CVJ and clival region, and to verify its effectiveness in terms of mid and upper clival access. Five silicone-injected cadaver heads were used. Following a standard antero-lateral approach, condylectomy and jugular tubercle drilling were performed, after which angled endoscopes were utilized to extend the bone resection to the clivus. A volumetric assessment of the amount of clival removal was carried out. A case of CVJ chordoma operated through this approach is presented. The hybrid antero-lateral transcondylar approach provides adequate exposure of the ventral CVJ, up to the dorsum sellae and the sphenoid sinus, the contralateral petrous apex, and the contralateral paraclival internal carotid artery (ICA). Approximately 60% of the total clival volume can be removed with this approach. The main limitation is the limited visualization of the ipsilateral paraclival ICA and petrous apex. The hybrid antero-lateral transcondylar approach is a valuable surgical option for CVJ tumor extending from C2 to the mid and upper clivus.

Aberrant course of internal carotid arteries (ICA) is rarely seen. In patients who are asymptomatic, anomalies may be detected incidentally during head and neck examination. Symptomatic patients may present with hearing loss, pulsatile tinnitus, dysphagia or a foreign body sensation in the posterior pharynx. If the retropharyngeal course of ICA remains undiagnosed, accidental biopsy or surgical intervention can result in life threatening complications. The abnormal course of ICA results from a complex defect in embryological development and is unlikely to be an acquired process. Previously, bilateral and unilateral agenesis, hypoplastic, retropharyngeal tortuous ICA and kissing sellar ICA have been described in literature. We used various imaging techniques to describe this first case of fused ICA with an aberrant course through the clivus and dorsum sellae. The patient also presented with patulous Eustachian tubes on both the left and right side.

Aim To assess the feasibility of using an endoscopic-assisted lateral supraorbital (LSO) approach and an endoscopic endonasal transclival approach (EETA) for basilar apex (BAX) aneurysms. Material and methods Ten cases with LSO approaches, with or without posterior clinoidectomy and endoscopic assistance, and 10 cases with EETA, with or without drilling of the dorsum sellae, were performed on 20 cadaveric heads. Anatomical exposure and surgical freedom at the BAX were evaluated. Results Anatomical exposure provided by the LSO approach was limited to the BAX and ipsilateral posterior cerebral artery (PCA) and increased with a mean value of 5.0 mm after posterior clinoidectomy; the basilar artery, contralateral PCA, and superior cerebellar arteries (SCAs) were visualized in all cases. Accordingly, surgical freedom was larger. Endoscopic assistance provided a significant increase in basilar artery exposure; however, surgical freedom did not increase markedly. The main advantage of EETA was the greatest exposure of the basilar artery. With drilling of the dorsum sellae, anatomical exposure increased by a mean value of 3.4 mm, and provided the greatest amount of surgical freedom and visualization of the basilar artery terminal bifurcation and of the SCAs in all cases. Conclusion The endoscopic-assisted LSO approach and the EETA may represent a feasible approach for treatment of BAX aneurysms lying within 5.0 mm below and within 3.4 mm above the dorsum sellae.

Background Most high-riding distal basilar trunk aneurysms can be surgically approached via the transsylvian route and its orbitozygomatic variant. However, on rare occasions, the basilar bifurcation may be unusually high and an approach above the carotid terminus may be required. Objective In this cadaveric study, we sought to determine the feasibility and exposure limits of the interlenticulostriate approach (ILSA). Methods A standard transsylvian approach was performed in 10 cerebral hemispheres of 5 formalin-fixed, silicone-injected cadaver heads. The interpeduncular cistern was exposed via the opticocarotid window, carotid-oculomotor window, and supracarotid ILSA window. The latter was measured and an aneurysm clip or ventriculostomy stylet was placed as high as possible through each corridor. Using noncontrast 3-D rotational angiography, clip/stylet positions were measured relative to the dorsum sellae. Results ILSA provided a 9.4 × 4.6 mm mean surgical corridor, just enough room for a standard clip applier. This space was limited by the carotid bifurcation inferiorly, the lenticulostriate arteries medially and laterally, and the optic tract superiorly. There was no difference between opticocarotid and carotid-oculomotor windows, in terms of clip position (+8.9 vs +8.6 mm, respectively; P = .78). In contrast, ILSA provided significantly improved superior exposure, compared with either approaches (mean stylet position: +14.3 mm; P = .005). The exposure benefit afforded by ILSA was consistent across all 10 hemispheres, ranging from +2.5 to +8 mm. Conclusion For high-riding distal basilar trunk aneurysms that cannot be reached via the frontotemporal orbitozygomatic approach, ILSA can provide a viable route of access. Vascular neurosurgeons should be familiarized with this approach.

Endoscopy in cerebellopontine angle surgery is an increasingly used technique. Despite of its advantages, the shortcomings arising from the complex anatomy of the posterior fossa are still preventing its widespread use. To overcome these drawbacks, the goal of this study was to define the anatomy of different endoscopic approaches through the retrosigmoid craniotomy and their limitations by surgical windows. Anatomical dissections were performed on 25 fresh human cadavers to describe the main approach-routes. Surgical windows are spaces surrounded by neurovascular structures acting as a natural frame and providing access to deeper structures. The approach-routes are trajectories starting at the craniotomy and pointing to the lesion, passing through certain windows. Twelve different windows could be identified along four endoscopic approach-routes. The superior route provides access to the structures of the upper pons, lower mesencephalon, and the upper neurovascular complex through the suprameatal, superior cerebellar, and infratrigeminal windows. The supratentorial route leads to the basilar tip and some of the suprasellar structures via the ipsi- and contralateral oculomotor and dorsum sellae windows. The central endoscopic route provides access to the middle pons and the middle neurovascular complex through the inframeatal, AICA, and basilar windows. The inferior endoscopic route is the pathway to the medulla oblongata and the lower neurovascular complex through the accessory, hypoglossal, and foramen magnum windows. The anatomy and limitations of each surgical windows were described in detail. These informations are essential for safe application of endoscopy in posterior fossa surgery through the retrosigmoid approach.

Background: Pituitary gland dysfunction might be predicted by examining the alteration of Sella turcica during the routine radiological examination of lateral cephalogram. Aim: The study aimed to analyze the variation in size and shape of sella turcica according to age and gender on lateral cephalogram among the people in the south zone of Chennai city. Materials and Method: A series of lateral cephalogram images from 200 patients comprising 94 males and 106 females were collected retrospectively from archives in the database. The shape and size of sella turcica were measured digitally. Statistical analysis was done using the Chi-square test and unpaired sample t-test. Results: The frequency of distribution of shapes of sella turcica among the people in Chennai city was 46% normal followed by 15.5% irregular dorsum sellae, 14.5% pyramidal shape, 11.5% bridging, 7% oblique anterior wall, 5.5% double contour. The length and depth of Sella turcica was greater in males when compared with that of the females which were statistically significant (P < 0.01). The depth and diameter were higher in the 10–20 years age group than the 20–30 year age group, which was statistically significant (P = 0.01). Conclusion: The size of Sella turcica alters between different age groups and gender. Variations in the shape of Sella turcica were present in nearly half of the individuals in the present study. Thus, the morphology of Sella turcica should be assessed as a part of routine radiographic examination.

Sellar spine, a bony spur extending anteriorly from the dorsum sellae, is a very rare anatomical variant. Several hypotheses regarding its etiology have been proposed, including the strongly supported theory of a cephalic ossified notochordal remnant. Sellar spine is usually detected incidentally in patients who have no definite symptoms, but several cases have reportedly accompanied endocrinopathies such as precocious puberty, hypopituitarism, or galactorrhea/oligomenorrhea. However, no published reports have described sellar spine in a patient with Cushing’s syndrome. We herein report a case of sellar spine detected during the evaluation of Cushing’s disease in a 29-year-old woman who underwent inferior petrosal sinus sampling, computed tomography, magnetic resonance imaging, and exploratory surgery. There was no evidence of a pituitary microadenoma, but a sellar spine was present in the operative field. Thus, the sellar spine might have caused Cushing’s syndrome in this case, although the exact mechanism is unknown.

Background To assess the positional accuracy of image fusions of the skull base region using different magnetic resonance imaging (MRI) and computed tomography (CT) image pairs. Methods An image set of 3D fast imaging employing steady-state acquisition-C (FIESTA-C) was used as the base image set. Image fusions were performed using an image set with different fields of view (FOVs): one with different matrix size, one with a different sequence of 3D spoiled gradient recalled acquisition, and one with different modality (CT), using a phantom including multi columnar objects. Position of columns at the center, and 4 and 8 cm from the center were measured. The displacements between the base image set and fused image set were measured. For slices with different z-positions, the displacement of the 8-cm column was assessed. For 20 clinical MRI cases, the distance between the dorsum sellae and the cranial nerves was measured. Results No significant differences were found between the different FOVs or image sequences. However, with the different matrix sizes and modalities, significant displacements were observed, although they were all within 0.5 mm. Similar displacements were observed in the slices at different z-positions. All cranial nerves were located within 40 mm of the dorsum sellae. Conclusions The displacements following image fusion were within approximately 0.5 mm, even at 8 cm from the center. This suggests that the region where the cranial nerves are located, within 40 mm of the dorsum sellae, had no risk of positional error following image fusion.

Background Intracranial chondromas are extremely rare and represent only 0.2% of all intracranial primary neoplasms. The histologic appearance lacks nuclear atypism and mitoses, and it usually shows low growth potential, although these benign features do not necessarily imply a good prognosis. Case Description A 44-year-old man was referred to our institution with a subarachnoid hemorrhage (SAH). He had a history of SAH 5 years previously that was diagnosed as unknown etiology at another hospital. Head magnetic resonance imaging showed a large tumor located in the prepontine cistern and extending up to the interpeduncular cistern, and the tumor was irregularly enhanced with contrast medium. Retrospective analysis of the original computed tomography of 5 years earlier identified a small contrast enhancing defect behind the dorsum sellae. Tumor removal was planned to prevent repeated SAH and control the apparently growing tumor. An extended transsphenoidal approach was performed. The pituitary gland was dissected from the bottom of the sellar floor and transposed forward to the prechiasmatic cistern with preservation of the pituitary stalk and its blood supply, and subtotal removal of the tumor was achieved. Postoperative diabetes insipidus disappeared within a few days, and the patient was discharged without neurologic or endocrinologic deficits. Histologic examination established the diagnosis as chondroma without a sarcomatous component. Follow-up examination 3 months after surgery showed a re-enlargement of the residual tumor, and gamma knife surgery was performed. Conclusions Intracranial chondroma sometimes manifests as intracranial hemorrhage and grows comparatively rapidly in a short period despite the benign histologic features. A long and careful follow-up period is essential.

We describe a nearly complete skull and mandible of a subadult of Euclastes wielandi, a pan-cheloniid turtle recently recovered at the Jean and Ric Edelman Fossil Park at Rowan University in Mantua Township, New Jersey, which yields new information about the osteology, ontogeny, and intraspecific variation of this taxon. The specimen was collected from the earliest Danian Main Fossiliferous Layer (MFL) of the Hornerstown Formation. Although discovered immediately adjacent to remains of two pleurodires, Taphrosphys sulcatus and Bothremys sp., the skull and mandible can be definitively assigned to Pan-Cheloniidae based on its V-shaped basisphenoid and rod-like rostrum basisphenoidale. Among three pan-cheloniid taxa known from the MFL, the specimen is assigned to Eu. wielandi based on its low skull with dorsally-directed orbits, symphyseal swelling in the mandibular triturating surface, and high dorsum sellae. Comparisons with other specimens of Eu. wielandi and adults and juveniles of other pan-cheloniids revealed variations in the type and timing of cranial ontogenetic changes in the clade, as well as anatomical traits subject to intraspecific variation, such as the depth of the sella turcica, paths of the foramina nervi hypoglossi, and development of a precolumellar fossa. The relative contribution of the frontal to the orbital margin and precise path of the prefrontal-supraorbital scale sulcus are subject to individual variation in Eu. wielandi, as well as ontogenetic variation and bilateral asymmetry in other cryptodirans, signifying that the widespread use of frontal retraction in taxon diagnoses and as a phylogenetic character should be reconsidered. As in multiple other taxa, the mandibular triturating surface expands through growth in Eu. wielandi, demonstrating that increased durophagy with age was a common life strategy among Cryptodira.

Patient: Male, 53 Final Diagnosis: Clivus chordoma Symptoms: Pain the eye Medication: — Clinical Procedure: — Specialty: Radiology Objective: Rare disease Background: The clivus is a depression in the anterior occipital bone of the skull base, posterior to the dorsum sellae, at the junction with the sphenoid bone. Chordoma is a rare tumor arising from embryonic remnants of the notochord and can be locally aggressive with a tendency to recur. The optimal management of this rare tumor remains controversial. A report of a case of recurrent chordoma of the clivus is presented to illustrate the value of volumetric three-dimensional (3-D) reconstruction with computed tomography (CT) and magnetic resonance imaging (MRI) to determine optimal surgical management. Case Report: A 53-year-old man presented with pain in the right orbital cavity, right proptosis, swelling of the right cheek, and bilateral loss of vision. He also had adrenal insufficiency. CT and contrast-enhanced (gadolinium) T1-weighted MRI with multiplanar acquisition were performed with volumetric 3-D reconstruction of the tumor, to increase the chances of treatment success. Surgical resection was performed to remove the tumor and reduce the risk of recurrence. Histology of the tumor was consistent with chordoma, supported by positive immunohistochemical staining for S-100 and epithelial membrane antigen (EMA). Conclusions: This report highlighted the value of 3-D volume imaging in the diagnosis and treatment planning in a rare case of recurrent chordoma of the clivus. Analysis of tumor volume may be an indicator of the efficacy of surgery, complementing the Response Evaluation Criteria In Solid Tumors (RECIST) system and as a valuable tool to predict treatment outcome.