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Background Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction. Methods Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional–printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction. Results The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique. Conclusions In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

Introduction The aim of present study was to undertake detailed analysis of variations in morphology of orbito-meningeal foramen (OMF), a clinically relevant entity due to possible association with major arterial branches. Materials & methods The study was conducted on 70 bony orbits of 35 dry adult human skulls. Precise identification of OMF's were ensured and other known bony canals in the orbit were excluded. All observations and measurements were undertaken by two observers independently to reduce chances of error. Results Overall incidence of OMF was 71.24% (left side 76% and right side 68%) and were present as single entity in orbit in most cases (80.56%) with multiplicity noted. The OMF's in present study were classified according to three parameters: size of lumen (large/medium/small), termination of canal in cranial fossa (M-Type/A -Type/ND Type) and bony component of orbit where it was located (frontal/sphenoid/fronto-sphenoid suture). Variations were noted regarding the morphology of OMF across all the three parameters in comparison to published literature. Most of the large OMF (80%) were of M-Type (opened in the middle cranial fossa). M-Type of OMF were single entities in 78.26% cases and were distributed proportionately across all three bony components of orbit. Conclusion Based on analysis of findings it is suggested that presence of solitary OMF with large (>0.3 mm) lumen in any of the three bony components of orbit is mostly M-Type and has a high possibility of a major arterial branch passing through it. Findings could be useful towards pre-operative workup before orbital surgeries. Knowledge regarding the variations in morphological details of OMF may reduce the risk of inadvertent vascular injury in orbital region.

Aiming at being part of the discussion about the cognitive functioning of patients with arachnoid cysts (AC) and the value of neuropsychological testing in these patients, we present our study in which we investigated the cognitive functioning of 32 children with ACs of the middle cranial fossa. We compared the Stanford Binet 5 (SB 5) results obtained by the patients with the population mean values and analysed the relation between the patients' clinical details and the results of SB 5. The main conclusions of this research are: (1) In SB 5 tasks, the tested group performed worse than the population mean, which could be related to AC of the middle cranial fossa. Deficits concern especially visuospatial reasoning, quantitative reasoning, and knowledge. The obtained results indicate the coexistence of cognitive impairment and AC of the middle cranial fossa. (2) In patients with AC, neuroimaging information has only limited predictive ability regarding cognitive syndromes. (3) The complaints reported in the interview are not necessarily objectively reflected in the clinical assessment. Neuropsychological assessment should be part of the management of all patients with AC. (4) Cognitive deficits in patients with AC may become more pronounced with age. Accordingly, increasing school difficulties in these patients should be expected. In light of the above, there is a clear indication of the need for neuropsychological support and support in school functioning for patients with AC. (5) Neuropsychological control in patients with AC is crucial not only with regard to treatment decisions but primarily for monitoring school performance and providing these patients with adequate neuropsychological and psychological support.

Background Lateral approaches to treat anterior cranial fossa lesions have evolved since the first frontotemporal approach described by Dandy in 1918. We describe a less invasive approach to perform extradural anterior clinoidectomy through a lateral supraorbital (LSO) approach for anterior circulation aneurysms and anterolateral skull base lesions. Methods The extended LSO approach involves performing a standard lateral supraorbital craniotomy followed by drilling of the sphenoid wing and lateral wall of the orbit through the frontal bony opening of the LSO approach, without any temporal extension of the craniotomy. This creates a frontopterio-orbital window exposing the periorbita; superior, medial, and anterior aspect of the temporal dura mater; and superior orbital fissure. After unroofing the superior orbital fissure, the meningo-orbital fold is cut, and the temporal dura mater is peeled from the lateral wall of the cavernous sinus to expose the anterior clinoid process allowing a standard opening of the optic canal and anterior clinoidectomy. Results The extended LSO approach and extradural anterior clinoidectomy allowed access to 4 sphenoid wing/anterior clinoidal meningiomas, 5 anterior circulation aneurysms, 2 temporomesial lesions, and 1 orbital/cavernous sinus abscess. Postoperatively, 2 patients had transient hemiparesis, 2 patients had transient third nerve palsy, and 1 patient had minimal visual field deterioration. All patients had a modified Rankin Scale score ≤1 at 8-week follow-up. Conclusion The extended LSO approach opens a new route (frontopterio-orbital window) to perform extradural anterior clinoidectomy safely and increases surgical exposure, angles, and operability of a less invasive keyhole craniotomy (LSO approach) to treat anterior cranial fossa lesions.

Objective Spontaneous cerebrospinal fluid leaks are most commonly located along the anterior skull base. Sphenoidal localization is less common, and clival localization is even rarer. We analyzed a group of patients with spontaneous leaks and selected patients with clival localization. This article discusses surgical management of these entities and provides a brief literature review regarding spontaneous clival leaks. Methods Of a cohort of 67 patients who presented to our departments with a spontaneous leak during the period 2005–2014, a retrospective data analysis was performed on 6 patients with clival localization of the defect. A skull base repair with a multilayered reconstruction was performed in 3 patients, and a single-layered reconstruction using a pedicled nasoseptal flap was performed in 3 patients. Results The patients included 6 women with a mean age of 60 years (range, 36–91 years). The mean length of the follow-up period was 69.5 months (range, 22–114 months). The overall success rate of the primary endoscopic repair was 83.3% (5 of 6 patients); this increased to 100% after revision surgery. Conclusions This series, although numerically limited, suggests that a minimally invasive endoscopic repair of idiopathic clival leaks may be accomplished with an acceptable rate of morbidity and excellent outcomes. Moreover, the pedicled nasoseptal flap has been confirmed to be the “workhorse” for the reconstruction of clival defects.

This study summarizes our experience of treating three rare cases of traumatic superior dislocation of the mandibular condyle into the cranial fossa and provides a potential treatment algorithm. Between the years 2002 and 2012, three patients with traumatic superior dislocation of the mandibular condyle into the cranial fossa were admitted to our department. After evaluating the interval from injury to treatment, the associated facial injuries including neurological complications, and the computed tomography imaging findings, an individualized treatment plan was developed for each patient. One patient underwent closed reduction under general anaesthesia. Two patients underwent open reduction with craniotomy and glenoid fossa reconstruction. All three patients were followed up for 1 year. Mouth opening and occlusal function recovered well, but all patients had mandibular deviation during mouth opening. Closed reduction under general anaesthesia, open surgical reduction with craniotomy, and mandibular condylotomy are the three main treatment methods for traumatic superior dislocation of the mandibular condyle into the cranial fossa. The treatment method should be selected on the basis of the interval from injury to treatment, associated facial injuries including neurological complications, and computed tomography imaging findings.

A técnica clássica para o implante coclear é realizada através de mastoidectomia e timpanotomia posterior. A abordagem pela fossa craniana média provou ser uma alternativa valiosa, embora venha sendo usada para o implante coclear apenas esporadicamente e sem normatização. OBJETIVO: Descrever uma nova abordagem para expor o giro basal da cóclea para o implante coclear através da fossa craniana média. MÉTODO: Cinquenta ossos temporais foram dissecados. A cocleostomia foi realizada através de uma abordagem via fossa craniana média, na parte mais superficial do giro basal da cóclea, usando o plano meatal e seio petroso superior como pontos de reparo. A parede lateral do meato acústico interno foi dissecada após o broqueamento e esqueletização do ápice petroso. A parede dissecada do meato acústico interno foi acompanhada longitudinalmente até a cocleostomia. Design: Estudo anatômico de osso temporal. RESULTADOS: Em todos os ossos temporais, apenas a parte superficial do giro basal da cóclea foi aberta. A exposição do giro basal da cóclea permitiu que as escalas timpânica e vestibular fossem visualizadas. Assim, não houve dificuldade na inserção do feixe de eletrodos através da escala timpânica. CONCLUSÃO: A técnica proposta é simples e permite exposição suficiente do giro basal da cóclea. The classic approach for cochlear implant surgery includes mastoidectomy and posterior tympanotomy. The middle cranial fossa approach is a proven alternative, but it has been used only sporadically and inconsistently in cochlear implantation. OBJECTIVE: To describe a new approach to expose the basal turn of the cochlea in cochlear implant surgery through the middle cranial fossa. METHOD: Fifty temporal bones were dissected in this anatomic study of the temporal bone. Cochleostomies were performed through the middle cranial fossa approach in the most superficial portion of the basal turn of the cochlea, using the meatal plane and the superior petrous sinus as landmarks. The lateral wall of the internal acoustic canal was dissected after the petrous apex had been drilled and stripped. The dissected wall of the inner acoustic canal was followed longitudinally to the cochleostomy. RESULTS: Only the superficial portion of the basal turn of the cochlea was opened in the fifty temporal bones included in this study. The exposure of the basal turn of the cochlea allowed the visualization of the scala tympani and the scala vestibuli, which enabled the array to be easily inserted through the scala tympani. CONCLUSION: The proposed approach is simple to use and provides sufficient exposure of the basal turn of the cochlea.

INTRODUCTIONThe authors explore a combined infratentorial-supracerebellar and telovelar approach in an adult, while avoiding vermian-splitting methods for a large, midline, fourth-ventricular tumor, unapproachable though a single traditional route. Experience with a combined surgical approach for pediatric patients has been published, but the authors believe that describing this combined method in an adult will provide a preliminary experience for further exploration of this approach in other adult patients.PRESENTATION OF CASEThe authors present a review of the literature along with the case of a 60-year-old man with slight ataxia who presented with a 1-month history of gait difficulty and memory lapse. His MRI of the brain showed mild hydrocephalus and a large tumor of the fourth ventricle. Surgical removal through a suboccipital craniotomy was attempted, and part of the tumor overlying the tectum and the superior cerebellar velum was removed without difficulty. However, despite inferior retraction of the vermis, which allowed further resection of the tumor from the fourth ventricle, residual tumor in the caudal surgical resection cavity was present. Partial transection of the vermis was considered, but avoided because of potential neurological deficits. Instead, the authors redirected their approach and exposed the residual tumor by transecting the inferior medullary velum and removed additional tumor while avoiding the floor of the fourth ventricle. The infratentorial-supracerebellar and telovelar approach resulted in total gross resection of the tumor.DISCUSSIONFor patients with large midline tumors that arise from the superior vermis or the quadrigeminal plate and fill the upper third of the fourth ventricular space, this combined approach may offer a unique possibility of safe tumor removal.CONCLUSIONThis case demonstrates the benefit of a combined approach for a select group of patients.

Resumen Objetivos Conocer por medio de una encuesta la actuacion de los anestesiologos espanoles en el manejo perioperatorio de los pacientes intervenidos neuroquirurgicamente de enfermedades de fosa posterior del craneo. Material y metodos Se remitio a los servicios de anestesiologia de hospitales con servicio de neurocirugia un cuestionario con un planteamiento cerrado sobre la participacion de los anestesiologos en el tratamiento perioperatorio de los pacientes sometidos a cirugia de fosa posterior. Resultados De los 73 hospitales nacionales publicos que disponen de servicio de neurocirugia, completaron el formulario 42 (57,5%). En 36 centros se realiza la cirugia de fosa posterior con el paciente en sedestacion, aunque se emplea con menor frecuencia que el decubito lateral o el decubito prono. La monitorizacion neurologica especifica es escasa, asi como el empleo del Doppler precordial y/o transcraneal para la deteccion de embolia vascular aerea. La tecnica anestesica mas empleada en estos procedimientos es la intravenosa. En menos del 10% de los centros se emplea oxido nitroso, y en un 15% se evitan los bloqueadores neuromusculares cuando se usa monitorizacion neurofisiologica intraoperatoria. Los problemas cardiovasculares durante la cirugia se refieren como muy frecuentes en el 29% de los centros, mientras que en el postoperatorio las complicaciones referidas como mas habituales son los deficit de pares craneales, el edema de via aerea (23%) y los vomitos postoperatorios (47%). Conclusiones Los resultados obtenidos de la encuesta muestran que en las cirugias de fosa posterior la sedestacion se utiliza menos que el decubito prono y que apenas se usa monitorizacion neurofisiologica intraoperatoria.

This article focuses on selected key anatomic considerations in anterior skull base surgery, briefly reviews common pathologies of the paranasal sinuses, and provides an overview of surgical approaches, complications, and results.

Anterior craniofacial resection has become a standard procedure for management of lesions of the anterior skull base. During the last 2 decades, modifications of the classic anterior craniofacial resection have been reported. With the introduction of endoscopic sinus techniques and instrumentation, surgeons have begun to use endoscopic approaches for management of anterior skull base lesions. This article describes endoscopic modifications of anterior craniofacial resection.

The prerequisite for the correct diagnosis and accurate delineation of skull base lesions is familiarity with the complex anatomy of the skull base. Imaging plays a central role in the management of skull base disease because this region is often difficult to evaluate clinically. CT and MR imaging are complementary; they are often used together to demonstrate the full disease extent. This article focuses on the critical anatomy of the skull base and how this knowledge contributes to accurate disease assessment.

This article presents the surgical anatomy of the clivus, nasopharynx, and craniocervical junction as it relates to the transoral approach to the midline basicranium. Particular attention is given to the indications, limitations, and complications of this procedure. The transpalatal approach is discussed in detail. Finally, the transmandibular approach is also briefly discussed.

This article focuses on petroclival tumors, which are rare lesions of the posterior fossa-an area that is difficult to access. Because of their location, rarity, insidious growth, and relentless natural progression toward a fatal outcome, petroclival tumors pose major management problems. With improved microsurgical techniques, however, these tumors can be approached and removed with preservation of vital neural and vascular structures.

PhD, Medicine (Professor, FMRP-USP).Send correspondence to: Miguel Angelo Hyppolito. Av. Bandeirantes, no 3900, 12o andar. Monte Alegre. Ribeirao Preto - SP. Brazil. CEP: 14048-900.Medical School of Ribeirao Preto - University of Sao Paulo - University Hospital (FMRP - USP).FAEPA - HCRP - FMRP-USP.Paper submitted to the BJORL-SGP (Publishing Management System - Brazilian Journal of Otorhinolaryngology) on September 29, 2005;and accepted on October 16, 2012. cod. 1460.

This article provides an overview of the complex embryologic development and anatomic relationships of the cranial base. The processes of neural cell migration, and chondrocranial base formation and ossification are discussed. In addition, the relative sectional anatomy is addressed with the goal of providing a functional review for clinicians dealing with cranial base disorders. The complex influences of the surrounding matrix and diffusible factors involved in skull base development are sources of continuing investigation. Through elucidation of the mechanisms of basal cranial development, the understanding of congenital and pathologic disorders of this area as well as cranial base influence on facial growth will be enhanced greatly.

Intracranial schwannomas commonly arise from the vestibular nerve and less commonly from other cranial nerves. On rare occasions, they may be intraparenchymatous, intraventricularor intrasellar. However, the occurrence of a congenital solitary intracranial extradural schwannoma unrelated to any cranial nerve in the absence of von Recklinghausan's syndrome is exceptional. The authors report a unique, heretofore unreported case of a congenital temporal extradural schwannoma, unassociated with any known cranial nerve and with a transcranial extension presenting as a temporal fossa mass since birth in a 16-year-old female patient. Total resection of this tumour was uncomplicated. A brief review of the relevant literature is presented.

We report the first cytogenetic analysis of a leiomyosarcoma of the sinonasal tract, a rare neoplasm. Karyotypic analysis showed near-triploid and near-tetraploid modal chromosome numbers with extensive structural and numerical aberrations. Three consistent structural changes, including i(6p), der(10)ins(10;1)(q26;q23q44), and der(12)t(1;12)(q11;q24) were observed in most cells. A der(11)t(11;?)(p15;?) was observed in 14 of 20 cells. Clonal structural rearrangements, including i(1q), del(2)(q37), der(3)t(3;?)(p25;?), del(4)(q31), del(7)(q32), der(12)t(12;?)(p12;?), der(15), del(21)(q22), and der(X) were each observed in a few cells. Numerical changes, including trisomies for chromosomes 2-5, 7, 9, 11, 15, 17, 18, and 20 and monosomies 10 and 12 were observed. Comparison of our findings to those of leiomyosarcomas at different sites showed trisomies 7 and 20 and rearrangements of 11p12-p15 and 21q22.

Acute subdural hematoma of the posterior fosa (ASDH-PF) is a clinical rarity with a poor prognosis in teenagers or adults (mortality rate: 71%). We report the third case operated upon with success. The relevant literature is analysed and the characteristics of ASDH-PF are discussed, particularly in connection with the patient's age.

Syringomyelia (SM) in Cavalier King Charles spaniels (CKCS) has a complex pathophysiology. Recent studies support a relationship between altered venous drainage and cerebrospinal fluid flow dynamics. The aim of this study was to evaluate the relationship between venous sinus and parenchymal volume within the caudal cranial fossa (CCF) in CKCS with SM (n=22) and without SM (n=12) using magnetic resonance venography (MRV). MRI and MRV images were used to obtain volumetric calculations of CCF volume, as well as the percentage of this volume occupied by parenchyma (CCFP%) and venous sinuses (CCFV%). In CKCS with SM, CCFP% was significantly higher (P0.001), whilst CCFV% was significantly lower (P=0.001) than in CKCS without SM. These results support a role for reduced venous drainage and parenchymal 'overcrowding' of the CCF in the pathophysiology of SM.

Foreign bodies in the anterior cranial fossa are unusual. This is a case of a 50-year-old man who presented with a dental implant displaced into the anterior cranial fossae, which was removed endoscopically with dural reconstruction.

A wide variety of cystic appearing or low attenuation lesions in the midline posterior fossa can so closely resemble one another as to render specific histologic diagnosis from CT scans alone fraught with error. Absorption coefficients often overlap and are too nonspecific to infer consistently accurate histologic diagnosis. It is virtually impossible to separate cystic from noncystic, benign from malignant, and neoplastic from non-neoplastic lesions by absorption coefficients alone.