Skull Base Approaches Research Articles

Advances in Pituitary Surgery.

Pituitary surgery has advanced considerably in recent years with the exploration and development of various endoscopic approaches and techniques. Different endoscopic skull base approaches are being applied to access sellar tumors in different locations. Moreover, extracapsular dissection and cavernous sinus exploration have enabled gross total resection of sellar tumors where it could not have been achieved in the past. Techniques for skull base reconstruction have also progressed, allowing surgeons to remove larger and more complicated tumors than before. This review article discusses different endoscopic skull base approaches, surgical techniques for removing pituitary adenomas, and reconstruction methods for repairing postoperative low-flow and high-flow cerebrospinal fluid leakage.

Critical appraisal of minimally invasive keyhole surgery for intracranial meningioma in a large case series.

Meningioma surgery has evolved over the last 20 years with increased use of minimally invasive approaches including the endoscopic endonasal route and endoscope-assisted and gravity-assisted transcranial approaches. As the "keyhole" concept remains controversial, we present detailed outcomes in a cohort series. Retrospective analysis was done for all patients undergoing meningioma removal at a tertiary brain tumor referral center from 2008-2021. Keyhole approaches were defined as: use of a minimally invasive "retractorless" approach for a given meningioma in which a traditional larger approach is often used instead. The surgical goal was maximal safe removal including conservative (subtotal) removal for some invasive locations. Primary outcomes were resection rates, complications, length of stay and Karnofsky Performance Scale (KPS). Secondary outcomes were endoscopy use, perioperative treatments, tumor control and acute MRI FLAIR/T2 changes to assess for brain manipulation and retraction injury. Of 329 patients, keyhole approaches were utilized in 193(59%) patients (mean age 59±13; 30 (15.5%) had prior surgery) who underwent 213 operations; 205(96%) were skull base location. Approaches included: endoscopic endonasal (n = 74,35%), supraorbital (n = 73,34%), retromastoid (n = 38,18%), mini-pterional (n = 20,9%), suboccipital (n = 4,2%), and contralateral transfalcine (n = 4,2%). Primary outcomes: Gross total/near total (>90%) resection was achieved in 125(59%) (5% for petroclival, cavernous sinus/Meckel's cave, spheno-cavernous locations vs 77% for all other locations). Major complications included: permanent neurological worsening 12(6%), CSF leak 2(1%) meningitis 2(1%). There were no DVTs, PEs, MIs or 30-day mortality. Median LOS decreased from 3 to 2 days in the last 2 years; 94% were discharged to home with favorable 90-day KPS in 176(96%) patients. Secondary outcomes: Increased FLAIR/T2 changes were noted on POD#1/2 MRI in 36/213(17%) cases, resolving in all but 11 (5.2%). Endoscopy was used in 87/139(63%) craniotomies, facilitating additional tumor removal in 55%. Tumor progression occurred in 26(13%) patients, mean follow-up 42±36 months. Our experience suggests minimally invasive keyhole transcranial and endoscopic endonasal meningioma removal is associated with comparable resection rates and low complication rates, short hospitalizations and high 90-day performance scores in comparison to prior reports using traditional skull base approaches. Subtotal removal may be appropriate for invasive/adherent meningiomas to avoid neurological deficits and other post-operative complications, although longer follow-up is needed. With careful patient selection and requisite experience, these approaches may be considered reasonable alternatives to traditional transcranial approaches.

Surgical treatment of selected tumors via the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach without rerouting of the facial nerve.

The feasibility of a novel skull base approach - the navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach (NaMIPSI-A) without rerouting of the fallopian canal for selected jugular foramen tumors (JFTs) - has been demonstrated in a neuroanatomical laboratory study. Here, we present our clinical experience with the NaMIPSI-A for selected JFTs, with a particular focus on its efficacy and safety. All patients with JFTs who were treated via the NaMIPSI-A were included in this study. The JFTs were classified according to a modified Fisch classification. The neurological and neuroradiological outcome, the extent of tumor resection, and the approach-related morbidity were examined. Five patients (two women, three men; mean age 57years, range 48-65) were available. According to the modified Fisch classification, two JFTs were graded as C1, one as De1, and two as De2. Gross total resection (GTR) was achieved in three patients and near-total resection (NTR) in two. Postsurgically, no new neurological deficits and no approach-related morbidity and mortality occurred. One case with a postoperative cerebrospinal fluid leak was managed successfully with lumbar drainage. During the follow-up period (mean 67.6months, range 12-119months), tumor recurrence was noted in the NTR group but not in the GTR group. The NaMIPSI-A to the jugular foramen without rerouting of the fallopian canal is highly valuable for selected tumors of the jugular foramen. It is less invasive than other skull base approaches, and it allows safe and complete tumor removal in appropriate patients.

Discovery of a trans-sellar vascular supply for the pituitary gland.

The vasculature of the pituitary gland is discussed briefly and the details of an anatomical discovery of the vessels supplying the pituitary gland provided. Twenty latex injected cadaveric heads were dissected. Any vessels that were found to penetrate the sella turcica and travel to the pituitary gland were documented and measured. Additionally, 25 adult skulls were evaluated for the presence, size, and sites of bony foramina in the floor of sella turcica. Trans-sellar vessels were identified in 65% of specimens. There was a mean of 1.5 vessels per specimen consisting usually of a mixture of veins and arteries. The mean diameter of these vessels was 0.3 mm and the mean length from the sella turcica to the pituitary gland was 2.3 mm. These vessels were concentrated in the most concave part of the sella turcica. In bony specimens, the mean number of trans-sellar foramina was four. The diameter of these foramina ranged from 0.3 to 0.6 mm in size. The trans-sellar foramina were concentrated near the center part of the sella turcica and had no regular pattern. The pituitary gland receives at least some blood supply and drainage via vessels traveling along the septum of the sphenoidal sinuses and through the sella turcica. Knowledge of such vessels might lead to a better understanding of the vascular supply and drainage of the pituitary gland and would be useful during skull base approaches such as trans-nasal approaches to the pituitary gland.

Large Pontine Cavernoma Operated by Anterior Petrosal Approach-Two-Dimensional Operative Video.

Brainstem cavernoma is a challenging neurosurgical pathology and microsurgery remains the only treatment option. Although the decision-making between interventional and conservative approach to this disease may be complex, malformations presenting multiple bleedings are usually good candidates for surgery. 1 On the other hand, microsurgical resection of cavernomas can offer an effective resolution with acceptable morbidity. In this video, we present a case of pontine cavernoma with multiple hemorrhages in a young patient. The anatomical characteristic of the lesion defines the best suitable craniotomy for surgery. In this case, an anterior petrosal approach 2 3 4 was used to access the peritrigeminal area and safely perform the resection. Anatomical considerations are described on this skull base approach along with the rationale and benefits of this exposure. Electrophysiological neuromonitoring is essential for this kind of procedure and preoperative tractography also enabled the best understanding of the disease. Finally, we also discuss alternative managements and potential complications. 5 With the patient's consent, we also show the excellent clinical evolution after few weeks of recovery and the restoration of the corticospinal tract, previously displaced by the cavernoma, to its original position.

Anatomy for Endoscopic Endonasal Skull Base Surgery

Endoscopic endonasal skull base surgery has become popular due to its minimally invasive nature to the patient and the development of various medical devices. The reason why it is considered less invasive is that it is possible to reach the anterior skull base lesion using the corridor of the nasal cavity and paranasal sinuses. The roles of the nasal sinuses include acting as breathing pathways, warming, humidifying, and filtering of inhaled air, olfaction, and being a resonant cavity, all of which are important for a comfortable life, and the loss of these functions reduces the quality of life. Therefore, to perform endoscopic endonasal skull base surgery in a minimally invasive and safe manner, it is necessary to understand the anatomy of the nasal sinuses to reach anterior skull base lesions while preserving nasal structures as much as possible. This article describes the normal local anatomy of the nasal cavity and the paranasal sinuses, as well as the surgical techniques, especially the anterior skull base approach and the pterygopalatine fossa approach, for endoscopic endonasal skull base surgery.

Three-Dimensional Modeling for Augmented and Virtual Reality-Based Posterior Fossa Approach Selection Training: Technical Overview of Novel Open-Source Materials.

Selection of skull base approaches is a critical skill for complex cranial surgery, which demands nuanced understanding of neuroanatomy and pathology. To develop novel pedagogical resources for approach selection education and assessment. A prospectively maintained skull base registry was screened for posterior fossa tumors amenable to 3-dimensional (3D) modeling of multiple operative approaches. Inclusion criteria were high-resolution preoperative and postoperative computed tomography and MRI studies (≤1 mm) and consensus that at least 3 posterior fossa craniotomies would provide feasible access. Cases were segmented using Mimics and modeled using 3-Matic. Clinical Vignettes, Approach Selection Questionnaire, and Clinical Application Questionnaire were compiled for implementation as a teaching/testing tool. Seven cases were selected, each representing a major posterior fossa approach group. 3D models were rendered using clinical imaging for the primary operative approach, as well as a combination of laboratory neuroanatomic data and extrapolation from comparable craniotomies to generate 2 alternative approaches in each patient. Modeling data for 3D figures were uploaded to an open-sourced database in a platform-neutral fashion (.x3d) for virtual/augmented reality and 3D printing applications. A semitransparent model of each approach without pathology and with key deep structures visualized was also modeled and included for comprehensive understanding. We report a novel series of open-source 3D models for skull base approach selection training, with supplemental resources. To the best of our knowledge, this is the first such series designed for pedagogical purposes in skull base surgery or centered on open-source principles.

Resection of Skull Base Meningioma With Extensive Extracranial Extension: 2-Dimensional Operative Video.

Jugular foramen meningiomas are rare tumors with distinguishing clinical, radiological, and surgical considerations.1,2 They involve the lower cranial nerves, invade the temporal bone, occlude jugular vein and sigmoid sinus, and involve internal carotid and vertebral arteries. Their location is prime for an extensive extracranial cervical extension. They might reach giant size with extension from the Meckel cave in the cerebellopontine angle to the carotid bifurcation in the neck while exhibiting only minor symptoms. Surgical morbidity is associated mainly with lower cranial nerves deficits. Radical surgical removal has been considered impossible with vascular encasement and is associated with a considerable risk of vascular injury. With careful and thorough preoperative evaluation, including evaluating the adequacy of the cerebral collateral and applying an appropriately tailored skull base approach,3 radical tumor resection can be achieved with the expectation of a good outcome.3,4 Meticulous microsurgical dissection of the tumor involving the internal carotid artery in the neck would permit radical resection without vascular damage and avoiding the need for vascular reconstruction.5 We demonstrate this technique in a 47-year-old female patient presented in the year 2007 having a giant jugular fossa tumor with extensive neck extension who consented to surgery. Image at 2:23 reused with permission from Al-Mefty O, Teixeira A. Complex tumors of the glomus jugulare: criteria, treatment, and outcome. J Neurosurg. 2002;97(6):1356-1366, by permission from JNSPG. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_vf9v0duk"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]}

Cadaver-Free Neurosurgical Simulation Using a 3-Dimensional Printer and Augmented Reality.

Training to become a neurosurgeon takes time and effort, with the training requirements continuing to increase. As such, more efficient educational tools are needed. To evaluate the use of 3-dimensional (3D) printing and augmented reality (AR) systems within neurosurgical training programs. The skull and its structures were segmented using normal computed tomography and MRI and printed with a 3D printer. Basic procedures (burr-hole trephination and other craniotomies) and advanced procedures of skull base approaches (anterior clinoidectomy, anterior petrosectomy, and mastoidectomy) were practiced with the printed model. Skull base approaches were practiced in an AR system. After the training program, a questionnaire was administered to the trainees about the effectiveness of the program. The basic procedure program was conducted four times with 22 trainees. Twenty trainees indicated that the present simulation program was important to their education (average of 4.9/5.0). When asked whether the model was similar to a human skull, the average score was 4.5 of 5 points. The advanced procedure program was conducted five times with 10 trainees. All 10 answered that the simulation program was a useful tool for training on skull base approaches (average of 5/5). All respondents answered that they would be able to perform the skull base approaches in patients after completing the training program (an average of 4.7/5). The simulation-based training program using 3D-printed anatomy with an AR system was demonstrated to be an important adjunct to training neurosurgery. It provides trainees a realistic environment to improve skills and performance during clinical practice.

Surgical resection of giant extrasellar thyrotropinoma: Use of orbitozygomatic and endoscopic endonasal approach

Background: Thyrotropinomas (TSHoma) are rare pituitary adenomas.Case Description: A 34-year-old female presented with mild bitemporal field defect in third trimester with intact pituitary function. MRI demonstrated an enhancing lesion from the posterior planum to suprasellar, interpeduncular and prepontine cisterns with chiasmal compression and right fetal posterior communicating artery encasement. With no sellar expansion, the differentials included meningioma or craniopharyngioma. She underwent a postpartum expanded endoscopic endonasal transtuberculum transchiasmatic sulcus approach [Video 1]. The lesion was debulked in the chiasmatic cistern to decompress the chiasm with preservation of superior hypophyseal perforators. Pituitary transposition and midclival approach to access the retrosellar component was not undertaken pending formal histology as the lesion encased the perforators and was atypical for the outlined differentials. In addition, the diaphragm was intact. Postoperatively, visual field normalized and the patient developed mild diabetes insipidus. Following the diagnosis of TSHoma (with an abnormal thyroid function test [TFT]) and due to patient preference and slightly increased risk of CSF leak with revisional endoscopic procedure, she underwent an orbitozygomatic craniotomy (pretemporal and transsylvian approach) without tentorial division to resect the disease in the interpeduncular and prepontine cisterns [Video 1]. The anatomical triangles and tumor characteristics facilitated this. A residual cuff was left along the base of the stalk and the floor of the third ventricle to preserve the superior hypophyseal and thalamoperforators. Postoperatively, the patient had normal TFT without any neurological deficit.Conclusion: Operative treatment strategy is presented for a rare large challenging multicompartmental extrasellar TSHoma using endoscopic endonasal and open skull base approaches.

Establishing the First Neurosurgical Skill Laboratory in West Africa: An Initiative for an Affordable Regional Education Center

BackgroundThe benefits of a neurosurgical skill laboratory (NSL) are unquestionable. Despite the increasing number of sub-Saharan African neurosurgeons, few cadaveric laboratories are available for neurosurgical education. The first of its kind in West Africa, a NSL opened in 2019 in Abidjan, Cote d’Ivoire to promote neurosurgeons' education and technical skills. We have described our experience in creating and running this facility.MethodsNSL is a private academic center in Abidjan, Cote d’Ivoire. It includes 2 rooms dedicated to cadaveric hands-on training and microscopic neurosurgery and multipurpose rooms, which contain 7 table-mounted microscopes and 3 endoscopes. The designed layout replicates an operating room. The curriculum was designed to meet the needs for training for complex brain and spine surgeries.ResultsThe training covers skull base (conventional and extended) approaches, microsuturing, and anterolateral and posterior approaches for spine surgeries. The training was open to residents and consultants. The faculty members included anatomists, neurosurgeons, otolaryngologists, and orthopedists. Additionally, the NSL welcomes fellows from foreign countries. Fellows from 4 countries have been trained, and 14 educational activities have been organized.ConclusionsIn the present report, we have provided insight into a sub-Saharan African neurosurgical laboratory striving toward an affordable and self-sustainable center. The short-term goal of the NSL is to be a center for developing technical skills for African neurosurgeons for better patient outcomes.

Skull Base Approaches for Tuberculum Sellae Meningiomas: Institutional Experience in a Series of 34 Patients.

(1) Background: The aim of the present study was to evaluate our institutional outcome in tuberculum sellae meningioma (TSM) patients treated microsurgically using multiple skull base approaches, including a transcranial approach and an extended endonasal transsphenoidal approach. (2) Materials and Methods: This is a retrospective study that includes 34 patients with TSM. The study aimed to observe the efficacy of the different common approaches used by a single neurosurgeon. All the patients were evaluated preoperatively and during follow-up with campimetry, head CT scan, and post-contrast MRI. (3) Results: After a transcranial approach, visual acuity improved in 86.20%, was stable in 10.34%, and deteriorated in 3.45%. Through transsphenoidal surgery, vision improved in 80%, was static in 20%, and deteriorated in 0%. Transcranial approaches included pterional, mini-bifrontal basal, and supraciliary keyhole microscopic craniotomies. Gross total removal was performed in 58.82%, near total in 10.34%, and partial removal in 3.45%. The transcranial/supraciliary keyhole endoscopic-assisted approach showed a gross total removal rate of 80%, and near total in 20%. The transsphenoidal approach showed a gross total removal rate of 60%, near total in 20%, and partial removal in 20%. (4) Conclusion: Endoscopic-assisted keyhole supraciliary mini craniotomy for resection of tuberculum sellae meningioma offers low morbidity and good visual outcome. The endonasal route is preferred for the removal of TSM when they are small and midline placed. The major limitation of this approach is a narrow surgical corridor and the restriction on midline-placed lesions. Gross total removal was better achieved with mini-bifrontal basal and pterional craniotomies.

Endoscopic superior eyelid transorbital approach: how I do it.

The endoscopic transorbital approach to the skull base is currently growing in popularity, and it is nowadays progressively used as a skull base approach. Clinical experience, along with detailed anatomical knowledge, makes this technique safe and effective. We present a step by step description of our technique based on the most recent anatomic references, and clinical experience. In order to better understand every phase of the procedure, we propose to keep on the following scheme, that is (1) skin phase; (2) working space; (3) lesion removal; (4) reconstruction. Hence, alone or in combination with the well-known endonasal pathway, the transorbital avenue seems to be a useful approach for selected skull base lesions. We present our technique, along with an anatomic analysis on cadaveric specimens. Detailed knowledge of surgical anatomy, and a specific stepwise analysis of each part of the surgical procedure, is notably useful in order to safely and effectively perform a superior eyelid endoscopic transorbital surgery to the skull base.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Far Lateral Approach.

Introduction Skull base neuroanatomy is classically taught using surgical atlases. Although these texts are critical and rich resources for learning three-dimensional (3D) relationships between key structures, we believe they could be optimized and complemented with step-by-step anatomical dissections to fully meet the learning needs of trainees. Methods Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A far lateral craniotomy was performed by each of three neurosurgery resident/fellow at varying stages of training. The study objective was the completion and photodocumentation of the craniotomy to accompany a stepwise description of the exposure to provide a comprehensive, intelligible, and anatomically oriented resource for trainees at any level. Illustrative case examples were prepared to supplement approach dissections. Results The far lateral approach provides a wide and versatile corridor for posterior fossa operation, with access spanning the entire cerebellopontine angle (CPA), foramen magnum, and upper cervical region. Key Steps Include The study includes the following steps: positioning and skin incision, myocutaneous flap, placement of burr holes and sigmoid trough, fashioning of the craniotomy bone flap, bilateral C1 laminectomy, occipital condyle/jugular tubercle drilling, and dural opening. Conclusion Although more cumbersome than the retrosigmoid approach, a far lateral craniotomy offers unparalleled access to lesions centered lower or more medially in the CPA, as well as those with significant extension into the clival or foramen magnum regions. Dissection-based neuroanatomic guides to operative approaches provide a unique and rich resource for trainees to comprehend, prepare for, practice, and perform complex cranial operations, such as the far lateral craniotomy.

Maturation of the internal auditory canal and posterior petrous bone with relevance to lateral and posterolateral skull base approaches

Anatomic knowledge of the internal auditory canal (IAC) and surrounding structures is a prerequisite for performing skull base approaches to the IAC. We herein perform a morphometric analysis of the IAC and surgically relevant aspects of the posterior petrous bone during pediatric maturation, a region well-studied in adults but not children. Measurements of IAC length (IAC-L), porus (IAC-D) and midpoint (IAC-DM) diameter, and distance from the porus to the common crus (CC; P-CC) and posterior petrosal surface (PPS) to the posterior semicircular canal (PSC; PPS-PSC) were made on thin-cut axial CT scans from 60 patients (grouped by ages 0–3, 4–7, 8–11 12–15, 16–18, and > 18 years). IAC-L increased 27.5% from 8.7 ± 1.1 at age 0–3 to 11.1 ± 1.1 mm at adulthood (p = 0.001), with the majority of growth occurring by ages 8–11. IAC-D (p = 0.52) and IAC-DM (p = 0.167) did not significantly change from ages 0–3 to adult. P-CC increased 31.1% from 7.7 ± 1.5 at age 0–3 to 10.1 ± 1.5 mm at adulthood (p = 0.019). PPS-PSC increased 160% from 1.5 ± 0.7 at age 0–3 to 3.9 ± 1.2 mm at adulthood (p < 0.001). The majority of growth in P-CC and PPS-PSC occurred by ages 12–15. Knowledge of these patterns may facilitate safe exposure of the IAC in children.

Maturation of the sella turcica and parasellar region: Surgical relevance for anterior skull base approaches in pediatric patients

ObjectiveTraditional and extended transnasal transsphenoidal approaches provide direct access to a variety of anterior skull base pathologies. Despite increased utilization of transnasal approaches in children, anatomic studies on pediatric skull base maturation are limited. We herein perform a surgically relevant morphometric analysis of the sella and parasellar regions during pediatric maturation. MethodsMeasurements of sellar length (SL), sellar depth (SDp), sellar diameter (SDm), interclinoid distance (ID), intercavernous distance (ICD), and the presence of sphenoid sinus pneumatization (SSP), and sphenoid sinus type (SST) were made on thin-cut CT scans from 60 patients (evenly grouped by ages 0–3, 4–7, 8–11 12–15, 16–18, and >18 years) for analysis. Data were analyzed by sex and age groups using t-tests and linear regression. ResultsSella and parasellar parameters did not differ by sex. SL steadily increased from 8.5 ± 1.2 mm to 11.5 ± 1.6 mm throughout development. SDp and SDm increased from 6.0 ± 0.9 mm to 9.3 ± 1.4 mm and 9.0 ± 1.6 mm to 14.4 ± 1.8 mm during maturation, with significant interval growth from ages 16–18 to adult (p < 0.01). ID displayed significant growth from ages 0–3 to 4–7 (18.0 ± 2.4 mm to 20.7 ± 1.9 mm; p = 0.002) and ICD from ages 0–3 to 8–11 (12.0 ± 1.8 mm to 13.5 ± 2.1 mm; p < 0.001), without further significant interval growth. SSP was not seen in patients < 3, but was 100% by ages 8–11. SSTs progressed from conchal/presellar (60% at ages 4–7) to sellar/postsellar (80% at adulthood). ConclusionThe sella and parasellar regions have varied growth patterns with development. Knowledge of the expected maturation of key anterior skull base structures may augment surgical planning in younger patients.

Prevalence of Petrooccipital Fissure Fusion: Osteological Study with Application to Approaches to the Skull Base and Imaging Interpretation

The petrooccipital fissure (POF) has relevance to skull base approaches, various tumors and craniosynostoses, and some cases of age-related hearing loss. However, the prevalence of fusion and classification of such is rarely found in the extant medical literature. One-hundred and 10 dry human skulls (220 sides) were used for this study. The skulls were evaluated for fusion of the POF. Both the endocranial and exocranial aspects of the POF were analyzed. A classification scheme was developed to better describe the location of POF fusion. A fused POF was identified on 36 sides (16.4%) and commonly found bilaterally (11%). Of these, 30 sides (83.3%) were completely fused (type I) and 6 sides (2.7%) were partially fused (types II and III). For the partially fused fissures, the fused part was on all but 2 sides with the most anterior portion of the petrous part of the temporal bone and adjacent clivus (type II). For the 2 sides (both right sides), the fusion was more posteriorly located between the petrous part of the temporal bone and lateral clivus (type III). Fusion of the POF was more often found in specimens with a partially or fully ossified petroclival ligament. Completely fused POF was positively correlated to sides with an intrajugular bony septum. A POF fusion was relatively common and associated with an ossified petroclival ligament and intrajugular bony septation. Such a prevalence is important for clinicians and skull base surgeons interpreting imaging of the skull base.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Endoscopic Endonasal Approach to the Orbit.

Introduction Although endonasal endoscopic approaches (EEA) to the orbit have been previously reported, a didactic resource for educating neurosurgery and otolaryngology trainees regarding the pertinent anatomy, techniques, and decision-making pearls is lacking. Methods Six sides of three formalin-fixed, color latex-injected cadaveric specimens were dissected using 4-mm 0- and 30-degree rigid endoscopes, as well as standard endoscopic equipment, and a high-speed surgical drill. The anatomical dissection was documented in stepwise three-dimensional (3D) endoscopic images. Following dissection, representative case applications were reviewed. Results EEA to the orbit provides excellent access to the medial and inferior orbital regions. Key steps include positioning and preoperative considerations, middle turbinate medialization, uncinate process and ethmoid bulla removal, complete ethmoidectomy, sphenoidotomy, maxillary antrostomy, lamina papyracea resection, orbital apex and optic canal decompression, orbital floor resection, periorbita opening, dissection of the extraconal fat, and final exposure of the orbit contents via the medial-inferior recti corridor. Conclusion EEA to the orbit is challenging, in particular for trainees unfamiliar with nasal and paranasal sinus anatomy. Operatively oriented neuroanatomy dissections are crucial didactic resources in preparation for practical endonasal applications in the operating room (OR). This approach provides optimal exposure to the inferior and medial orbit to treat a wide variety of pathologies. We describe a comprehensive step-by-step curriculum directed to any audience willing to master this endoscopic skull base approach.

Sphenoid sinus pneumatization in Middle Eastern patients - implications for endoscopic skull base approaches

Sphenoid sinus pneumatization in Middle Eastern patients - implications for endoscopic skull base approaches

Tailored Skull Base Approach to Management of Intracranial Aneurysms.

Surgical management of intracranial aneurysms (IAs) remains one of the most challenging and dynamic tasks for neurosurgeons. The rivalry between modern time microsurgery and progress in endovascular intervention has provided a great arena for advancement and lead to redefine training concept and referral pattern. Both approaches has its own merits, risks and complications and the best outcome is achieved by case individualization and complimentary multidisciplinary approach.The recent innovation in microscopic and endoscopic tailored skull base approaches, intraoperative 3D and ICG video-angiography, design of high quality aneurysm clips, and refinement of cerebral bypass techniques enhance IAs neurosurgical management and their clinical outcome. The command of tailored skull base approaches should be part of the training curriculum of young generation of neurosurgeons to compliment the emerging treatment options of endovascular intervention.