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Background: Reconstruction of the skull base after an expanded endonasal approach (EEA) is critical to achieve a good outcome. A novel technique based on the use of a pedicled nasoseptal flap has proven to be a reliable and versatile reconstructive option for extensive defects of the skull base. Data regarding the potential dimensions of a nasoseptal flap are lacking in the literature. This pilot study was developed to help optimize the design of the nasoseptal flap and to ensure that when harvesting the flap, its width and length are adequate to reconstruct the defects that are created by various EEAs. Methods: We analyzed the computed tomographic (CT) scans of four patients who underwent EEAs for skull base lesions. Sagittal and coronal CT reconstructions were generated from axial images. The measurements were divided into skull base measurements, flap dimensions required to cover skull base defects resulting from various EEAs, and potential maximal dimensions of the nasoseptal flap. Measurements were studied for three different EEAs: sellar/transplanar, transclival, and transcribiform/anterior skull base. We measured the potential defects for each of these EEAs and the nasoseptal flap dimensions that would be required to reconstruct them. We estimated all dimensions based on the most extensive defect that could result with each EEA. We then compared these with various modifications of the nasoseptal flap. Results: Two male and two female patients were studied. Twenty-seven measurements were taken to compare the different skull base defects and nasoseptal flaps. Conclusions: The length of the nasal septum comprises sufficient mucoperichondrium and mucoperiosteum to allow the harvesting of a nasoseptal flap that could cover any defect resulting from an anterior skull base, a transsellar/transplanar, or a transclival EEA. Similarly, the height of the nasal septum has the potential to yield a nasoseptal flap with a width that is adequate to cover the laterolateral aspect of any defect of the anterior skull base and clivus. Skull base defects resulting from combined EEAs, such as those that would create a defect that comprises the skull base from sella turcica to frontal sinus, are beyond the potential dimensions of a single nasoseptal flap. This and other defects resulting from a combination of EEAs require other strategies, such as the use of bilateral nasoseptal flaps, or the use of other reconstructive options. [ABSTRACT FROM AUTHOR]

The contralateral transmaxillary corridor improves access to anterior petrous apex lesions back to the level of the internal auditory canal without the need to mobilize the paraclival internal carotid artery. In this video, we present the case of 31-yo female that presented with new left abducens palsy during pregnancy. Imaging revealed a heterogeneous enhancing extradural mass within the left petrous apex region extending posterior to the horizontal segment of the petrous internal carotid artery, consistent with chondrosarcoma. Chondrosarcomas are the 2 nd most common osseous malignancy but only consist of 0.2% of all intracranial tumors 1,2 . They are thought to derive from persistent cartilaginous rests retained after endochondral ossification 3 . Given that surgery is a mainstay of treatment 4,5,6 , a combined endoscopic endonasal and contralateral transmaxillary approach was selected to achieve maximal resection. The patient consented to the procedure. A complete resection of the mass was performed with pathology demonstrating a grade 2 chondrosarcoma. The patient tolerated the procedure without any complications, the left abducens palsy resolved in follow-up by 3 weeks, and a multidisciplinary tumor board recommended postoperative observation without adjuvant therapy 7 . An endoscopic endonasal and contralateral transmaxillary approach is a feasible option for petrous apex lesions such as chondrosarcoma., (Copyright © 2024. Published by Elsevier Inc.)

Background: With modern treatment paradigms, olfactory neuroblastoma (ONB) has favorable overall survival (OS); however, the incidence of recurrence remains high. The primary aims of this study were to delineate the prognosis of recurrence of ONB and explore how recurrence subsites are associated with OS, disease-specific survival (DSS), and further recurrence., Methods: A retrospective chart review of ONB cases from nine academic centers between 2005 and 2021 was completed. Tumor characteristics, recurrence subsites, timelines to recurrence, additional recurrences, and survival estimates were determined using descriptive and time-to-event analyses., Results: A final cohort of 233 patients was identified, with 70 (30.0%) patients recurring within 50.4 (standard deviation ±40.9) months of diagnosis on average, consisting of local (50%), neck (36%), intracranial (9%), and distant (6%) recurrence. Compared with subjects without recurrence, patients with recurrence had significantly different primary American Joint Committee on Cancer T stage (p < 0.001), overall stage (p < 0.001), and modified Kadish scores (p < 0.001). Histopathology identified that dural involvement and positive margins were significantly greater in recurrent cases. First recurrence was significantly associated with worse 5-year DSS (hazard ratio = 5.62; p = 0.003), and subjects with neck or local recurrence had a significantly better DSS compared to intracranial or distant recurrence., Conclusions: Recurrent cases of ONB have significantly different stages and preoperative imaging factors. Patients with local or neck recurrence, however, have better DSS than those with intracranial or distant recurrence, independent of initial tumor stage or Hyams grade. Identifying specific factors that confer an increased risk of recurrence and DSS is important for patient counseling in addition to surveillance planning., (© 2024 ARS‐AAOA, LLC.)

Background: Patients with sinonasal malignancy (SNM) present with significant sinonasal quality of life (QOL) impairment. Global sinonasal QOL as measured by the 22-item Sinonasal Outcomes Test (SNOT-22) has been shown to improve with treatment. This study aims to characterize SNOT-22 subdomain outcomes in SNM., Methods: Patients diagnosed with SNM were prospectively enrolled in a multi-center patient registry. SNOT-22 scores were collected at the time of diagnosis and through the post-treatment period for up to 5 years. Multivariable regression analysis was used to identify drivers of variation in SNOT-22 subdomains., Results: Note that 234 patients were reviewed, with a mean follow-up of 22 months (3 months-64 months). Rhinologic, psychological, and sleep subdomains significantly improved versus baseline (all p < 0.05). Subanalysis of 40 patients with follow-up at all timepoints showed statistically significant improvement in rhinologic, extra-nasal, psychological, and sleep subdomains, with minimal clinically important difference met between 2 and 5 years in sleep and psychological subdomains. Adjuvant chemoradiation was associated with worse outcomes in rhinologic (adjusted odds ratio (5.22 [1.69-8.66])), extra-nasal (2.21 [0.22-4.17]) and ear/facial (5.53 [2.10-8.91]) subdomains. Pterygopalatine fossa involvement was associated with worse outcomes in rhinologic (3.22 [0.54-5.93]) and ear/facial (2.97 [0.32-5.65]) subdomains. Positive margins (5.74 [2.17-9.29]) and surgical approach-combined versus endoscopic (3.41 [0.78-6.05])-were associated with worse psychological outcomes. Adjuvant radiation (2.28 [0.18-4.40]) was associated with worse sleep outcomes., Conclusions: Sinonasal QOL improvements associated with treatment of SNM are driven by rhinologic, extra-nasal, psychological, and sleep subdomains., (© 2024 ARS‐AAOA, LLC.)

Purpose: Our institution uses two approaches for nasal mucosal preparation during endoscopic sinus surgery (ESS) to improve surgical field visualization: topical epinephrine (TE) versus topical cocaine with injection of lidocaine containing epinephrine (TCLE). We aimed to compare anesthetic outcomes after ESS using these techniques., Methods and Materials: We retrospectively identified adult patients at our institution who underwent ESS from May 2018 through January 2023 under general anesthesia with propofol and remifentanil infusions. Postoperative anesthetic outcomes, including pain and recovery time, were compared between patients who had mucosal preparation with TE versus TCLE using inverse probability of treatment weighting (IPTW) to adjust for potential confounders., Results: Among 1449 patients who underwent ESS, 585 had TE, and 864 had TCLE. Compared with TE, during anesthetic recovery, the TCLE group had fewer episodes of severe pain (numeric pain score ≥ 7) (IPTW-adjusted odds ratio, 0.65; 95 % CI, 0.49-0.85; P = .002), less opioid analgesic administration (IPTW-adjusted odds ratio, 0.55; 95 % CI, 0.44-0.69; P < .001), and shorter recovery room stay (IPTW-adjusted ratio of the geometric mean, 0.90; 95 % CI, 0.85-0.96; P = .002). Postoperative nausea and vomiting and postoperative sedation were similar between groups., Conclusions: Patients who received preparation of the nasal mucosa with TCLE, compared with TE, were less likely to report severe pain or receive an opioid analgesic in the postanesthesia recovery room and had faster anesthetic recovery. This observation from our large clinical practice indicates that use topical and local anesthetic during endoscopic sinus surgery may have benefit for ambulatory ESS patients., Competing Interests: Declaration of competing interest T.N.W. reports financial support from Medtronic Corporation, Merck, Enalare Therapeutics Inc., Takeda Pharmaceutical Company Limited, and Trevena Inc. J.K.S. reports financial support from Acclarent, Inc., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Objectives: The coexistence of complete carotico-clinoid bridge (CCB), an ossification between the anterior (ACP) and the middle clinoid (MCP), and an interclinoidal osseous bridge (ICB), between the ACP and the posterior clinoid (PCP), represents an uncommonly reported anatomic variant. If not adequately recognized, osseous bridges may complicate open or endoscopic surgery, along with the pneumatization of the ACP, especially when performing anterior or middle clinoidectomies., Methods: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines, a systematic scoping review was conducted up to June 5, 2023. PubMed, Scopus, Web of Science databases, and additional citations were searched. Two hundred high-resolution noncontrast computed tomography (CT) scans (400 sides) and 41 dry skulls (82 sides) were analyzed to identify the different morphology of sellar bridges, focusing on the coexistence of complete CCF and ICB. Two embalmed latex-injected heads with coexisting CCF and ICB were dissected step-by-step to show the anatomic relationship with the surrounding structures from an endoscopic and microscopic perspective., Results: A total of 19 articles were included. The review identified a complete CCF and ICB rate ranging from 4.92% to 6.3%. The analysis of 200 CT scans revealed a rate of coexistence in 4% of the cases, all encountered in White women. Two different types of interclinoid bridges were identified based on the degree of bone mineralization. Both endoscopic and macroscopic step-by-step dissections highlighted variability in morphology and consistency of the sellar bridges and the close relationship with the cavernous sinus neurovascular structures., Conclusion: The coexistence of CCF and ICB is an anatomic variation found in 4% of cases. Preoperative knowledge of the degree of mineralization and its relationship with surrounding structures is essential to performing safe surgery and minimizing cranial nerve and vascular injuries. Preoperative high-resolution CT scans can adequately identify these anatomic variations., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Objective: The use of composite chondromucosal nasal septal flaps (ccNSF) has been demonstrated to be effective in cadaveric studies for the anterior skull base and the orbit. However, their application in the clinical setting remains unexplored. Our study aims to introduce a new method for treating palatal defects using ccNSF. Additionally, we studied the average NSF area and compared it to the average palate area., Methods: We collected 108 CT scans from the medical records of patients without head and neck pathologies from a tertiary medical institution. We quantified the quadrangular (septal) cartilage and palate areas. Furthermore, we included a clinical case in which we used the ccNSF for the palatal defect reconstruction. This was to compare the mean area between the palate and the septal cartilage., Results: The ccNSF covered the palatal defect without any significant complications for the first 9 months of follow-up. A total of 102 CT scans met the inclusion criteria and were measured. We found that the mean quadrangular cartilage had a length of 2.50 (±0.52) cm, a width of 2.28 (±0.51) cm, and an area of 5.43 (±1.68) cm 2 . The mean palate length was 2.73 (±0.44) cm, with a width of 3.13 (±0.34) cm, and area of 7.87 (±1.43) cm 2 ., Conclusions: The ccNSF proved successful in palatal defect reconstruction, resulting in positive outcomes and no major complications until the 9-month follow-up. The ccNSF is a useful flap that avoids the use of free flap transfer and its associated morbidities., Level of Evidence: 4 Laryngoscope, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Background and Objectives: The trans-sinus transglabellar and bifrontal approaches offer direct access to the anterior cranial fossa. However, these approaches present potential drawbacks. We propose the biportal endoscopic transfrontal sinus (BETS) approach, adapting endoscopic endonasal approach (EEA) techniques for minimally invasive access to the anterior fossa, reducing tissue manipulation, venous sacrifice, and brain retraction., Methods: Six formalin specimens were used. BETS approach involves 2 incisions over the medial aspect of both eyebrows from the supraorbital notch to the medial end of the eyebrow. A unilateral pedicled pericranial flap is harvested. A craniotomy through the anterior table of the frontal sinus (FS) and a separate craniotomy through the posterior table are performed. Two variants of the approach (preservative vs cranialization) are described for opening and reconstruction of the FS based on the desired pathology to access. Bone flap replacement can be performed with titanium plates and filling of the external table defect with bone cement., Results: Like in EEA, this approach provides access for endoscope and multiple working instruments to be used simultaneously. The approach allows wide access to the anterior cranial fossa, subfrontal, and interhemispheric corridors, all the way up to the suprachiasmatic corridor and through the lamina terminalis to the third ventricle. BETS provides direct access to the anterior fossa, minimizing the level of frontal lobe retraction and providing potentially less tissue disruption and improved cosmesis. Cerebrospinal fluid fistula risk remains one of the major concerns as the narrow corridor limits achieving a watertight closure which can be mitigated with a pedicled flap. Mucocele risk is minimized with full cranialization or reconstruction of the FS., Conclusion: The BETS approach is a minimally invasive approach that translates the concepts of EEA to the FS. It allows excellent access to the anterior cranial fossa structures with minimal frontal lobe retraction., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Photogrammetry scans has directed attention to the development of advanced camera systems to improve the creation of three-dimensional (3D) models, especially for educational and medical-related purposes. This could be a potential cost-effective method for neuroanatomy education, especially when access to laboratory-based learning is limited. The aim of this study was to describe a new photogrammetry system based on a 5 Digital Single-Lens Reflex (DSLR) cameras setup to optimize accuracy of neuroanatomical 3D models. One formalin-fixed brain and specimen and one dry skull were used for dissections and scanning using the photogrammetry technique. After each dissection, the specimens were placed inside a new MedCreator® scanner (MedReality, Thyng, Chicago, IL) to be scanned with the final 3D model being displayed on SketchFab® (Epic, Cary, NC) and MedReality® platforms. The scanner consisted of 5 cameras arranged vertically facing the specimen, which was positioned on a platform in the center of the scanner. The new multi-camera system contains automated software packages, which allowed for quick rendering and creation of a high-quality 3D models. Following uploading the 3D models to the SketchFab® and MedReality® platforms for display, the models can be freely manipulated in various angles and magnifications in any devices free of charge for users. Therefore, photogrammetry scans with this new multi-camera system have the potential to enhance the accuracy and resolution of the 3D models, along with shortening creation time of the models. This system can serve as an important tool to optimize neuroanatomy education and ultimately, improve patient outcomes., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Sinonasal malignancies (SNMs) adversely impact patients' quality of life (QOL) and are frequently identified at an advanced stage. Because these tumors are rare, there are few studies that examine the specific QOL areas that are impacted. This knowledge would help improve the care of these patients., Methods: In this prospective, multi-institutional study, 273 patients with SNMs who underwent definitive treatment with curative intent were evaluated. We used the University of Washington Quality of Life (UWQOL) instrument over 5 years from diagnosis to identify demographic, treatment, and disease-related factors that influence each of the 12 UWQOL subdomains from baseline to 5 -years post-treatment., Results: Multivariate models found endoscopic resection predicted improved pain (vs. nonsurgical treatment CI 2.4, 19.4, p = 0.01) and appearance versus open (CI 27.0, 35.0, p < 0.001) or combined (CI 10.4, 17.1, p < 0.001). Pterygopalatine fossa involvement predicted worse swallow (CI -10.8, -2.4, p = 0.01) and pain (CI -17.0, -4.0, p < 0.001). Neck dissection predicted worse swallow (CI -14.8, -2.8, p < 0.001), taste (CI -31.7, -1.5, p = 0.02), and salivary symptoms (CI -28.4, -8.6, p < 0.001). Maxillary involvement predicted worse chewing (CI 9.8, 33.2; p < 0.001) and speech (CI -21.8, -5.4, p < 0.001) relative to other sites. Advanced T stage predicted worse anxiety (CI -13.0, -2.0, p = 0.03)., Conclusions: Surgical approach, management of cervical disease, tumor extent, and site of involvement impacted variable UWQOL symptom areas. Endoscopic resection predicted better pain, appearance, and chewing compared with open. These results may aid in counseling patients regarding potential QOL expectations in their SNM treatment and recovery course., (© 2024 The Author(s). International Forum of Allergy & Rhinology published by Wiley Periodicals LLC on behalf of American Academy of Otolaryngic Allergy and American Rhinologic Society.)

Introduction: Surgical techniques for sellar reconstruction include no reconstruction, use of synthetic materials, autologous grafts, and/or vascularized flaps. The aim of this study was to conduct a multi-center study comparing the efficacy and postoperative morbidity associated with different sellar reconstruction techniques., Methods: A retrospective chart review of patients who underwent endoscopic transsphenoidal surgery for pituitary tumors from five participating sites between January 2021 and March 2023 was performed. The variables included demographics, tumor characteristics, reconstruction technique, postoperative cerebrospinal fluid leak (CSF) leak, and 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Comparisons of postoperative complications, SNOT-22 scores, and duration of surgery by type of onlay reconstruction were evaluated using Fisher's exact test, analysis of variance, and Kruskal‒Wallis test., Results: Five hundred and one patients were identified. The median tumor size was 2.1 cm, and 64% were non-functioning. Intraoperative CSF leak was identified in 38% of patients. A total of 89% of patients underwent onlay reconstruction: 49% were reconstructed with mucosal grafts, 35% with nasoseptal flaps, and 5% with other onlay techniques. Nasoseptal flaps were utilized more frequently in the setting of giant pituitary adenomas (>3 cm), medial cavernous sinus wall resection, and high-flow intraoperative CSF leaks. Cases who utilized mucosal grafts had an overall shorter operating time (median: 183 min vs. 240 min; p < 0.001). Five postoperative CSF leaks were identified, and therefore, statistical analysis could not be performed for this complication., Conclusion: The effectiveness and morbidity of different sellar reconstruction techniques are comparable. Vascularized flaps were utilized more frequently in the setting of larger tumors and high-flow intraoperative CSF leaks., (© 2024 ARS‐AAOA, LLC.)

Objective: Nonfunctioning pituitary adenomas (NFPAs) present at a wide range of ages; it is possible that variable outcomes are based on patient age at presentation. This study aimed to explore long-term outcomes of patients with NFPAs following endonasal transsphenoidal surgery (ETS), considering age stratification., Methods: This retrospective study included 228 patients with NFPAs who underwent ETS, with a median follow-up period of 63 months. The outcomes included progression-free survival (PFS) rates and neurological and endocrinological outcomes. Age-stratified Kaplan-Meier and Cox proportional hazards analyses were performed. Patients were classified into four age groups: ≤ 49, 50-59, 60-69, and ≥ 70 years., Results: Age-stratified analysis showed a significant correlation between age and PFS in NFPAs (5-year PFS rates: 63.0% in those ≤ 49 years, 76.7% in those 50-59 years, 85.0% in those 60-69 years, and 88.1% in those ≥ 70 years; p = 0.001, log-rank test). Bivariate (HR 1.03, 95% CI 1.01-1.05; p = 0.001) and multivariable (HR 1.03, 95% CI 1.02-1.05; p = 0.001) analyses demonstrated that older age was significantly associated with longer PFS. Multivariable analysis also demonstrated that smaller maximum tumor diameter (HR 0.77, 95% CI 0.60-0.99; p = 0.036) and gross-total resection (HR 8.55, 95% CI 3.90-18.75; p = 0.001) were significantly associated with longer PFS. Multivariable logistic regression analysis demonstrated that only younger age was associated with postoperative improvement of male hypogonadism (HR 0.91, 95% CI 0.84-0.99; p = 0.019). Other postoperative neurological and endocrinological outcomes were not significantly associated with age., Conclusions: Older patients with NFPAs treated with ETS demonstrated a longer PFS. Of endocrinological outcomes studied, only male hypogonadism improvement was associated with younger patient age.

Background: Eagle syndrome (ES) was first described in 1937, to characterize elongation of the styloid process. It is rarely encountered by neurosurgeons but does present the potential for vascular sequelae and neurological complications., Demonstrative Cases: We discuss three patients with uncommon presentations of neurovascular compromise with uncommon symptomatology, secondary to ES. Their management ranged from retrospective diagnoses following self-limited events, antiplatelet therapy, and endovascular and surgical interventions., Discussion: While traumatic fractures, chiropractic manipulation, and history of prior neck surgery have been implicated as the etiologies for ES, congenital cases are common. The styloid process intimately interplays with adjacent neurovascular and nervous structures; its elongation can cause symptoms in 10% of patients., Conclusion: Awareness of this potentially dangerous but rare disease - more commonly seen by our otolaryngology colleagues - may help reduce diagnostic delays when an elongated styloid process is the cause, as surgery may be required.

Background: The impact of sinonasal malignancies (SNMs) on quality of life (QOL) at presentation is poorly understood. The Sinonasal Outcome Test (SNOT-22) and University of Washington Quality of Life (UWQOL) are validated QOL instruments with distinctive subdomains. This study aims to identify factors impacting pretreatment QOL in SNM patients to personalize multidisciplinary management and counseling., Methods: Patients with previously untreated SNMs were prospectively enrolled (2015-2022) in a multicenter observational study. Baseline pretreatment QOL instruments (SNOT-22, UWQOL) were obtained along with demographics, comorbidities, histopathology/staging, tumor involvement, and symptoms. Multivariable regression models identified factors associated with reduced baseline QOL., Results: Among 204 patients, presenting baseline QOL was significantly reduced. Multivariable regression showed worse total SNOT-22 QOL in patients with skull base erosion (p = 0.02). SNOT-rhinologic QOL was worse in women (p = 0.009), patients with epistaxis (p = 0.036), and industrial exposure (p = 0.005). SNOT extranasal QOL was worse in patients with industrial exposure (p = 0.016); worse SNOT ear/facial QOL if perineural invasion (PNI) (p = 0.027). Squamous cell carcinoma pathology (p = 0.037), palate involvement (p = 0.012), and pain (p = 0.017) were associated with worse SNOT sleep QOL scores. SNOT psychological subdomain scores were significantly worse in patients with palate lesions (p = 0.022), skull base erosion (p = 0.025), and T1 staging (p = 0.023). Low QOL was more likely in the presence of PNI on UW health (p = 0.019) and orbital erosion on UW overall (p = 0.03). UW social QOL was worse if palatal involvement (p = 0.023) or PNI (p = 0.005)., Conclusions: Our findings demonstrate a negative impact on baseline QOL in patients with SNMs and suggest sex-specific and symptom-related lower QOL scores, with minimal histopathology association. Anatomical tumor involvement may be more reflective of QOL than T-staging, as orbital and skull base erosion, PNI, and palate lesions are significantly associated with reduced baseline QOL., (© 2023 ARS‐AAOA, LLC.)

Objective: Several pathologies either invade or arise within the orbit. These include meningiomas, schwannomas, and cavernous hemangiomas among others. Although several studies describing various approaches to the orbit are available, no study describes all cranio-orbital and orbitocranial approaches with clear, surgically oriented anatomical descriptions. As such, this study aimed to provide a comprehensive guide to the microsurgical and endoscopic approaches to and through the orbit., Methods: Six formalin-fixed, latex-injected cadaveric head specimens were dissected in the surgical anatomy laboratory at the authors' institution. In each specimen, the following approaches were modularly performed: endoscopic transorbital approaches (ETOAs), including a lateral transorbital approach and a superior eyelid crease approach; endoscopic endonasal approaches (EEAs), including those to the medial orbit and optic canal; and transcranial approaches, including a supraorbital approach, a fronto-orbital approach, and a 3-piece orbito-zygomatic approach. Each pertinent step was 3D photograph-documented with macroscopic and endoscopic techniques as previously described., Results: Endoscopic endonasal approaches to the orbit afforded excellent access to the medial orbit and medial optic canal. Regarding ETOAs, the lateral transorbital approach afforded excellent access to the floor of the middle fossa and, once the lateral orbital rim was removed, the cavernous sinus could be dissected and the petrous apex drilled. The superior eyelid approach provides excellent access to the anterior cranial fossa just superior to the orbit, as well as the dura of the lesser wing of the sphenoid. Craniotomy-based approaches provided excellent access to the anterior and middle cranial fossa and the cavernous sinus, except the supraorbital approach had limited access to the middle fossa., Conclusions: This study outlines the essential surgical steps for major cranio-orbital and orbitocranial approaches. Endoscopic endonasal approaches offer direct medial access, potentially providing bilateral exposure to optic canals. ETOAs serve as both orbital access and as a corridor to surrounding regions. Cranio-orbital approaches follow a lateral-to-medial, superior-to-inferior trajectory, progressively allowing removal of protective bony structures for proportional orbit access.

Objectives: To report implementation and outcomes associated with a novel paid Summer Undergraduate Research Education Program (SREP) over the first 2 years in an academic otolaryngology program recruiting students underrepresented in medicine (URiM)., Methods: A 10-week program including a research bootcamp, curriculum, mentoring, and clinical shadowing was created. Grant funding to provide salary and support for transportation, conference attendance, and graduate school preparation or applications was procured. Primary objectives included (1) development of successful mentorship relationships; (2) increasing student-reported outcomes using pre- and post-program surveys to assess confidence, career planning, and overall satisfaction; (3) increasing exposure to medicine; (4) completion of an oral presentation; and (5) submission of a manuscript. Secondary objectives included abstract submission and completion of a graduate exam course or graduate school applications. Tertiary objectives included conference attendance and graduate school matriculation., Results: One hundred thirty-five total applications were reviewed (89 from year 1 and 46 from year 2). Twelve students were interviewed for 3 spots in year 1, while 11 students were interviewed for 6 spots in year 2 (median application score, 9.25 (range, 1-14); median interview score, 8.7 (range, 5.4-10); acceptance rate, 6.7% (9/135)). Students met all primary objectives. Mean program survey scores increased from 3.8 to 4.77 ( p  < 0.0001). Eight of nine students submitted an abstract to a national conference, with five of eight students accepted for a presentation. Two students were accepted into graduate school, while five others are on track for graduate school application., Conclusion: Identifying mentors, curriculum, and opportunities to meaningfully strengthen graduate school applications for URiM students through a clinically rigorous, financially supported, and research-focused summer program in an academic otolaryngology program is feasible and may be an effective means of increasing diversity in medicine and otolaryngology., Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-024-02021-z., Competing Interests: Conflict of InterestThe authors declare no conflict of interests., (© The Author(s) under exclusive licence to International Association of Medical Science Educators 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

The 3D stereoscopic technique consists in providing the illusional perception of depth of a given object using two different images mimicking how the right and left eyes capture the object. Both images are slightly different and when overlapped gives a three-dimensional (3D) experience. Considering the limitations for establishing surgical laboratories and dissections courses in some educational institutions, techniques such as stereoscopy and photogrammetry seem to play an important role in neuroanatomy and neurosurgical education. The aim of this study was to describe how to combine and set up realistic models acquired with photogrammetry scans in 3D stereoscopic projections. Three donors, one dry skull, embalmed brain and head, were scanned using photogrammetry. The software used for displaying the final realistic 3D models (Blender, Amsterdam, the Netherlands) is a free software and allows stereoscopic projection without compromising the interactivity of each model. By default, the model was exported and immediately displayed as a red cyan 3D mode. The 3D projector used in the manuscript required a side-by-side 3D mode which was set up with simple commands on the software. The final stereoscopy projection offered depth perception and a visualization in 360° of each donor; this perception was noted especially when visualizing donors with different cavities and fossae. The combination of 3D techniques is of paramount importance for neuroanatomy education. Stereoscopic projections could provide a valuable tool for neuroanatomy instruction directed at clinical trainees and could be especially useful when access to laboratory-based learning is limited., (© 2023 American Association for Anatomy.)

Objective: To evaluate recurrence patterns and survival after recurrence among patients with sinonasal mucosal melanoma (SNMM)., Methods: This was a multi-institutional retrospective review from seven U.S. institutions of patients with SNMM from 1991 to 2022. Recurrence was categorized as local, regional, distant, or multifocal. Kaplan-Meier tests were used to evaluate disease-free survival (DFS), overall survival (OS), and post-recurrence survival (PRS) reported with standard errors (SE) and log-rank testing used for comparison. Cox-regression was further used, with hazard ratios (HR) and 95% confidence intervals (CI) reported., Results: Among 196 patients with SNMM, there were 146 patients with recurrence (74.5%). Among all patients, 60-month DFS (SE) was 15.5% (2.9%), 60-month OS (SE) was 44.7% (3.7%), mean age ± standard deviation at diagnosis was 69.7 ± 12.5 years, and 54.6% were female. In 26 patients who underwent primary treatment of the neck, 60-month DFS did not differ from no treatment (p > 0.05). Isolated distant recurrence was most common (42.8%), followed by local (28.3%), multifocal (20.7%), and regional recurrence (8.3%). Among patients with regional recurrence in the neck, there was no 60-month PRS benefit for patients undergoing salvage neck dissection or radiation (p > 0.05). Among patients with distant recurrence, only immunotherapy was associated with improved 12-month PRS (HR = 0.32, 95% CI = 0.11-0.92, p = 0.034), and no treatment group was associated with improved 24- or 60-month PRS (p > 0.05)., Conclusion: SNMM is associated with a high recurrence rate and poor survival. Primary treatment of the neck was not associated with reduced recurrence, and immunotherapy for treatment of distant recurrence was associated with increased 12-month PRS., (© 2023 ARS-AAOA, LLC.)

Background: Quality of life (QOL) for individuals with sinonasal malignancy (SNM) is significantly under-studied, yet it is critical for counseling and may impact treatment. In this study we evaluated how patient, treatment, and disease factors impact sinonasal-specific and generalized QOL using validated metrics in a large cohort over a 5-year posttreatment time frame., Methods: Patients with SNM who underwent definitive treatment with curative intent were enrolled in a prospective, multisite, longitudinal observational study. QOL was assessed using the 22-item Sino-Nasal Outcome Test (SNOT-22) and University of Washington Quality of Life Questionnaire (UWQOL) instruments at pretreatment baseline and multiple follow-ups through 5 years posttreatment. Multivariable modeling was used to determine demographic, disease, and treatment factors associated with disease-specific and generalized physical and social/emotional function QOL., Results: One hundred ninety-four patients with SNM were analyzed. All QOL indices were impaired at pretreatment baseline and improved after treatment. SNOT-22 scores improved 3 months and UWQOL scores improved 6 to 9 months posttreatment. Patients who underwent open compared with endoscopic tumor resection had worse generalized QOL (p < 0.001), adjusted for factors including T stage. Pterygopalatine fossa (PPF) involvement was associated with worse QOL (SNOT-22, p < 0.001; UWQOL Physical dimension, p = 0.02). Adjuvant radiation was associated with worse disease-specific QOL (p = 0.03). Neck dissection was associated with worse generalized physical function QOL (p = 0.01). Positive margins were associated with worse generalized social/emotional function QOL (p = 0.01)., Conclusion: Disease-specific and generalized QOL is impaired at baseline in patients with SNM and improves after treatment. Endoscopic resection is associated with better QOL. PPF involvement, adjuvant radiation, neck dissection, and positive margins were associated with worse QOL posttreatment., (© 2023 ARS-AAOA, LLC.)

Purpose: The anatomy of the medial wall of the cavernous sinus (MWCS) and parasellar ligaments (PLs) has acquired increasing importance in endoscopic endonasal (EE) surgery of the cavernous sinus (CS), including resection of the MWCS in functioning pituitary adenomas (FPAs). Although anatomical studies have been published, it represents a debated topic due to their complex morphology. The aim is to offer a description of the PLs that originate from the MWCS and reach the lateral wall of the cavernous sinus (LWCS), proposing the "candy wrapper" model. The relationships between the neurovascular structures and histomorphological aspects were investigated., Methods: Forty-two CSs from twenty-one human heads were studied. Eleven specimens were used for EE dissection; five underwent a microscopic dissection. Five specimens were used for histomorphological analysis., Results: Two groups of PLs with a fan-shaped appearance were encountered. The anterior group included the periosteal ligament (55% sides) and the carotico-clinoid complex (100% sides), formed by the anterior horizontal and the carotico-clinoid ligaments. The posterior group was formed by the posterior horizontal (78% sides), and the inferior hypophyseal ligament (34% sides). The periosteal ligament originated inferiorly from the MWCS, reaching the periosteal dura. The anterior horizontal ligament was divided in a superior and inferior branch. The superior one continued as the carotid-oculomotor membrane, and the inferior branch reached the CN VI. The carotico-clinoid ligament between the middle and anterior clinoid was ossified in 3 sides. The posterior horizontal ligament was related to the posterior genu and ended at the LWCS. The inferior hypophyseal ligament followed the homonym artery. The ligaments related to the ICA form part of the adventitia., Conclusion: The "candy wrapper" model adds further details to the previous descriptions of the PLs. Understanding this complex anatomy is essential for safe CS surgery, including MWCS resection for FPAs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: For aggressive maxillary sinus and pterygopalatine fossa (PPF) tumors, an en-bloc pterygomaxillectomy may be indicated., Methods: Five head specimens were used to study the feasibility of an en-bloc pterygomaxillectomy. Eighty-five non-pathological CT scans were used to compare the superior edge of the inferior turbinate (IT) and the middle turbinate tail (MT) as landmarks for the pterygoid osteotomy., Results: Through a combined sublabial-subperiosteal incision and transoral route, a mid-sagittal osteotomy through the hard palate and an axial osteotomy below the infraorbital foramen were performed. For the endoscopic pterygoid osteotomy, an infra-vidian transpterygoid approach was performed, subsequently removing the pterygomaxillectomy en-bloc. As landmarks, the osteotomies at the level of the MT tail and IT resected the pterygoid plates completely, but the IT osteotomy was further away from the vidian canal (7.5 vs. 6 mm)., Conclusions: The endoscopic-assisted en-bloc pterygomaxillectomy is feasible. The IT landmark is safe and ensures complete resection of the pterygoid plates., (© 2023 Wiley Periodicals LLC.)

Hands-on dissections using cadaveric tissues for neuroanatomical education are not easily available in many educational institutions due to financial, safety, and ethical factors. Supplementary pedagogical tools, for instance, 3D models of anatomical specimens acquired with photogrammetry are an efficient alternative to democratize the 3D anatomical data. The aim of this study was to describe a technical guideline for acquiring realistic 3D anatomic models with photogrammetry and to improve the teaching and learning process in neuroanatomy. Seven specimens with different sizes, cadaveric tissues, and textures were used to demonstrate the step-by-step instructions for specimen preparation, photogrammetry setup, post-processing, and display of the 3D model. The photogrammetry scanning consists of three cameras arranged vertically facing the specimen to be scanned. In order to optimize the scanning process and the acquisition of optimal images, high-quality 3D models require complex and challenging adjustments in the positioning of the specimens within the scanner, as well as adjustments of the turntable, custom specimen holders, cameras, lighting, computer hardware, and its software. MeshLab® software was used for editing the 3D model before exporting it to MedReality® (Thyng, Chicago, IL) and SketchFab® (Epic, Cary, NC) platforms. Both allow manipulation of the models using various angles and magnifications and are easily accessed using mobile, immersive, and personal computer devices free of charge for viewers. Photogrammetry scans offer a 360° view of the 3D models ubiquitously accessible on any device independent of operating system and should be considered as a tool to optimize and democratize the teaching of neuroanatomy., (© 2023 American Association for Anatomy.)

Objectives: The previously described S-point, corresponds to the medial projection of the middle turbinate axilla in the superior nasal septum and has been identified as a common source of severe epistaxis. The objective is to define the anatomical patterns of vascularization of the S-point area that could explain its clinical relevance., Methods: Thirty-three nasal septums of latex-injected formalin-embalmed and fresh human cadaveric heads were dissected to analyze the arterial arrangement of the S-point area. Measurements and patterns of vascularization were described., Results: The S-point area, was consistently surrounded by a single or multiple arterial anastomotic arches consistently formed superiorly by the anterior ethmoidal and posterior ethmoidal artery branches, and inferiorly by the posterior septal artery. The caliber of the arterial arches was typically larger than the caliber of the arterial branches supplying them. A single arch was present in 36.3% of septums, and multiple arches in 63.6%. The mean distance from the S-point to the anterior limit of the arch was 9 mm, to the posterior arch when the present was 3 mm, to the superior limit 6 mm, to the inferior limit 6 mm, and to the nasal roof was 10 mm., Conclusion: This study demonstrates the dense arterial configuration of the S point area, which is characterized by a single or multiple vascular arches of greater caliber than the branches of origin. This finding could explain why the S-point area is a frequent source of epistaxis, and guide its surgical cauterization when an obvious vascular ectasia is not visualized., Level of Evidence: N/A Laryngoscope, 133:2075-2080, 2023., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction  The clival, paraclival, and craniocervical junction regions are challenging surgical targets. To approach these areas, endoscopic endonasal transclival approaches (EETCAs) and their extensions (far-medial approach and odontoidectomy) have gained popularity as they obviate manipulating and working between neurovascular structures. Although several cadaveric studies have further refined these contemporary approaches, few provide a detailed step-by-step description. Thus, we aim to didactically describe the steps of the EETCAs and their extensions for trainees. Methods  Six formalin-fixed cadaveric head specimens were dissected. All specimens were latex-injected using a six-vessel technique. Endoscopic endonasal middle and inferior clivectomies, far-medial approaches, and odontoidectomy were performed. Results  Using angled endoscopes and surgical instruments, an endoscopic endonasal midclivectomy and partial inferior clivectomy were performed without nasopharyngeal tissue disruption. To complete the inferior clivectomy, far-medial approach, and partially remove the anterior arch of C1 and odontoid process, anteroinferior transposition of the Eustachian-nasopharynx complex was required by transecting pterygosphenoidal fissure tissue, but incision in the nasopharynx was not necessary. Full exposure of the craniocervical junction necessitated bilateral sharp incision and additional inferior mobilization of the posterior nasopharynx. Unobstructed access to neurovascular anatomy of the ventral posterior fossa and craniocervical junction was provided. Conclusion  EETCAs are a powerful tool for the skull-base surgeon as they offer a direct corridor to the ventral posterior fossa and craniocervical junction unobstructed by eloquent neurovasculature. To facilitate easier understanding of the EETCAs and their extensions for trainees, we described the anatomy and surgical nuances in a didactic and step-by-step fashion., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Background: Juvenile nasopharyngeal angiofibromas (JNAs) are rare, benign, and locally invasive nasopharyngeal tumors. Endoscopic endonasal resection is effective, non-invasive, with low complication rates. Until recently, endoscopic resection was not suitable for intracranially invasive tumors., Purpose/method: We describe resection steps of an intracranially extending JNA with a combined endoscopic endonasal and endoscopic-assisted sublabial transmaxillary approaches. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video., Conclusion: Surgical excision of JNAs by a combined endoscopic endonasal and sublabial transmaxillary approaches represents a safe and effective treatment for selected intracranially invasive JNA., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The anterior cranial fossa (ACF) is a complex anatomical region that can be affected by a broad spectrum of pathology. For the surgical treatment of these lesions, many approaches have been described, each of them with different scope and potential surgical complications, often associated with significant morbidity. Traditionally, tumors involving the ACF have been operated by transcranial approaches; however, in the last two decades, endoscopic endonasal approaches (EEAs) have been gaining popularity. In this work, the authors review and describe the anatomical aspects of the ACF and the technical nuances of transcranial and endoscopic approaches for tumors located in this region. Four approaches were performed in embalmed cadaveric specimens and the key steps were documented. Four illustrative cases of ACF tumors were selected to demonstrate the clinical application of anatomical and technical knowledge, which are essential in the preoperative decision-making process.

The vomer-rostrum mucosal flap is a useful technique utilizing vascularized mucosa of the rostrum and posterior septum to cover exposed hyperostotic bone following wide sphenoidotomy surgery. Laryngoscope, 133:552-556, 2023., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction: Esthesioneuroblastoma (ENB) is a rare malignant neoplasm arising from the olfactory epithelium of the cribriform plate. Although survival is excellent with a reported 5-year overall survival (OS) of 82%, recurrence is frequent and occurs in 40-50% of cases. This study investigates the characteristics of ENB recurrence and the subsequent prognosis of patients with recurrence., Methods: The clinical records of all patients diagnosed as having ENB with subsequent recurrence at a tertiary hospital from 1 January 1960 to 1 January 2020 were retrospectively reviewed. Overall survival (OS) and progression-free survival (PFS) were reported., Results: A total of 64 out of 143 ENB patients had recurrences. In total, 45 out of 64 recurrences met the inclusion criteria and were included in this study. From these, 10 (22%) had a sinonasal recurrence, 14 (31%) had an intracranial recurrence, 15 (33%) had a regional recurrence, and 6 (13%) had a distal recurrence. The average interval from initial treatment to recurrence was 4.74 years. There were no differences in rates of recurrence with respect to age, sex, or types of surgery (endoscopic, transcranial, lateral rhinotomy, and combined). The time to recurrence was shorter for Hyams grades 3 and 4 compared to Hyams grades 1 and 2 (3.75 years vs. 5.70 years, p < 0.05). Patients with recurrence limited to the sinonasal region had a lower overall primary Kadish stage compared to recurrences beyond the sinonasal region (2.60 vs. 3.03, p < 0.05). A total of 9 (20%) out of 45 patients developed secondary recurrence. Following recurrence, the subsequent 5-year OS and PFS were 63 and 56%, respectively. The mean time to secondary recurrence after treatment of the primary recurrence was 32 months, which was significantly shorter than the time to primary recurrence (32 months vs. 57 months, p = 0.048). The mean age of the secondary recurrence group is significantly older than the primary recurrence group (59.78 years vs. 50.31 years, p = 0.02). No statistically significant differences were observed between the secondary recurrence group and the recurrence group in terms of their overall Kadish stages or Hyams grades., Conclusions: Following an ENB recurrence, salvage therapy appears to be an effective therapeutic option with a subsequent 5-year OS of 63%. However, subsequent recurrences are not infrequent and may require additional therapy.

Aspirin-exacerbated respiratory disease (AERD) is characterized by abnormal arachidonic acid metabolism leading to chronic rhinosinusitis with nasal polyposis (CRSwNP), asthma, and upper and/or lower respiratory symptoms after ingestion of cyclooxygenase-1 inhibiting nonsteroidal antiinflammatory drugs. Diagnosis is clinical and may involve an aspirin challenge. Inflammatory biomarkers may be useful for diagnosis and treatment monitoring. Conventional medical management for asthma and CRSwNP is often inadequate. Endoscopic sinus surgery followed by continued medical management with or without aspirin desensitization frequently improves symptoms and objective disease measures. Biological agents targeting eosinophilic inflammation are promising alternatives to conventional management., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: A detailed understanding of the neurovascular relationships between the optic nerve (ON) and the ophthalmic artery (OA) in the optic canal (OC) is paramount for safe surgery. We focused on the neurovascular anatomy of this area from both an endoscopic endonasal and transcranial trajectories to compare the surgical exposures and perspectives offered by these different views and provide recommendations to increase the intraoperative safety., Methods: Twenty sides of ten formalin-fixed, latex-injected head specimens were utilized. The surgical anatomy and anatomical relationships of the OA in relationship to the ON along their intracranial and intracanalicular segments was studied from endoscopic endonasal and transcranial perspectives., Results: Three types of OA-ON relationships at the origin of the OA were identified: inferomedial (type 1, 35%), inferior (type 2, 55%), and inferolateral (type 3, 10%). The endoscopic endonasal trajectory offers an inferomedial perspective of the ON-OA neurovascular complex, in which the OA, especially when located inferomedially, is first encountered. When comparing with the transcranial view, all OA were covered by the nerve, type 1 was located below the medial third, type 2 below the middle third, and type 3 below the lateral third of the OC. The mean extension of the intracanalicular portion of both OA and ON was 8.9 mm, while the intracranial portion of the OA and ON were 9.3 mm and 12.4 mm, respectively. The OA, endoscopically, is located within the inferior half of the OC, and occupies 39%, 43%, and 42% of the OC height at its origin, mid, and end points, respectively. The mean distance between the superior margin of the OC at its origin and superior margin of the OA is 1.4 mm., Conclusions: Detailed anatomical understanding of the OC, and the ON and OA at their intracranial and intracanalicular segments is paramount to safe surgery. When opening the OC dura endoscopically, our results suggest that a medial incision along the superior third of the OC with a proximal to distal direction is recommended to avoid injury of the OA., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Introduction  The endoscopic endonasal transpterygoid approach (EETPA) with or without the addition of the endoscopic-assisted sublabial anterior transmaxillary approach (ESTA) has become increasingly utilized for lesions posterior to the pterygopalatine fossa (PPF), including infratemporal fossa (ITF), lateral recess of the sphenoid sinus, Meckel's cave, petrous apex, and parapharyngeal space. The main goal of this study is to develop an educational resource to learn the steps of the EETPA for trainees. Methods  EETPA and ESTA were performed in 12 specimens by neurosurgery trainees, under supervision from the senior authors. One EETPA and one ESTA were performed on each specimen on opposite sides. Dissections were supplemented with representative cases. Results  After a wide unilateral sphenoidotomy, ethmoidectomy, and partial medial maxillectomy, the anteromedial bone limits of the PPF were identified and drilled out. The pterygoid progress was modularly removed. By enlarging the opening of the posterior and lateral walls of the maxillary sinus through EETPA and ESTA, respectively, the neurovascular and muscular compartments of the PPF and ITF were better identified. The EETPA opens direct corridors to the PPF, medial ITF, middle cranial fossa, cavernous sinus, Meckel's cave, petrous apex, and internal carotid artery. If a more lateral exposure of the ITF is needed, the ESTA is an appropriate addition. Conclusion  Despite the steep learning curve of the EETPA, granular knowledge of its surgical anatomy and basic surgical steps are vital for those advancing their learning in complex endoscopic approaches to the ventral skull base when expanding the approach laterally in the coronal plane., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objective: Esthesioneuroblastoma (ENB) is a rare malignant neoplasm arising from the olfactory epithelium of the cribriform plate. The goal of this study was to update our oncologic outcomes for this disease and explore prognostic factors associated with survival., Materials and Methods: We performed a retrospective analysis of patients with ENB treated at a single tertiary care institution from January 1, 1960, to January 1, 2020. Univariate and multivariate analysis was performed. Overall survival (OS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were reported., Results: Among 143 included patients, the 5-year OS was 82.3% and the 5-year PFS was 51.6%; 5-year OS and PFS have improved in the modern era (2005-present). Delayed regional nodal metastasis was the most common site of recurrence in 22% of patients (median, 57 months). On univariate analysis, modified Kadish staging (mKadish) had a negative effect on OS, PFS, and DMFS (p < 0.05). Higher Hyams grade had a negative effect on PFS and DMFS (p < 0.05). Positive margin status had a negative effect on PFS (p < 0.05). Orbital invasion demonstrated worsening OS (hazard ratio, 3.1; p < 0.05). On multivariable analysis, high Hyams grade (3 or 4), high mKadish stage (C+D), and increasing age were independent negative prognostic factors for OS (p < 0.05). High Hyams grade (3+4), high mKadish stage (C+D), age, and positive margin status were independent negative prognostic factors for PFS (p < 0.05). High Hyams grade (3+4) was an independent negative prognostic factor for DMFS (p < 0.05)., Conclusions: Patients with low Hyams grade and mKadish stage have favorable 5-year OS, PFS, and DMFS., (© 2022 ARS-AAOA, LLC.)

Background: The lingual process of the sphenoid bone (LP) and the petrolingual ligament (PLL) surround laterally the internal carotid artery within the middle cranial fossa (MCF)., Objective: To study the LP and the PLL and anatomical variations considering their relationships with different structures and landmarks within the MCF, especially oriented toward the endoscopic endonasal approaches., Methods: Seventy-two sides of dry skulls and 20 sides of embalmed specimens were studied. The measurements of the LP and the PLL were obtained, considering important landmarks in the MCF., Results: The LP had a mean length and height of 5 mm and 3 mm, respectively. Its distance from the foramen lacerum was 6 mm, from the foramen ovale 10 mm, foramen rotundum 15 mm, and petrous apex 9 mm. In 44 sides (61.11%), the LP partially closed the lateral aspect of the carotid sulcus; in 17 sides (23.61%), it was found as a near-ring; and in 11 sides (15.2%), it was considered rudimentary. Considering the PLL, its length and height were, respectively, 9 mm, and 4 mm., Conclusion: The LP and PLL separate the carotid artery at the inferior aspect of Meckel's cave and constitute important landmarks for endoscopic endonasal approaches to Meckel's cave and MCF, and their identification and removal is essential for internal carotid artery mobilization in this area., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Objective: The aim of this study is to verify if the length of the nasoseptal flap is sufficient to cover the tuberculum sellae and planum sphenoidale of sphenoidal sinuses with varied degrees of pneumatization., Methods: Retrospective study of paranasal sinus computed tomography comparing the potential length of the nasoseptal flap and the length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches in conchal, presellar, sellar, incomplete postsellar, and complete postsellar sphenoidal sinuses., Results: The length of the nasoseptal flap required for reconstruction of transtuberculum and transplanum approaches was directly related to the degree of pneumatization of the sphenoidal sinus. The nasoseptal flap length was adequate to cover the cranial base after transtuberculum approaches of all cases from the conchal, presellar, and sellar groups and the majority of cases from postsellar pneumatization. For transplanum approaches, the nasosseptal flap was sufficient to reconstruct defects in most cases from conchal, pre-sellar, and sellar type sinuses and in 54,9% and 19,2% in incomplete and complete postsellar, respectively., Conclusions: In well pneumatized sphenoidal sinus, the nasoseptal flap may not be sufficient to cover the cranial base after transtuberculum and transplanum approaches., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by Mutaz B. Habal, MD.)

Purpose: Traditional endoscopic endonasal approaches to the cavernous sinus (CS) open the anterior CS wall just medial to the internal carotid artery (ICA), posing risk of vascular injury. This work describes a potentially safer midline sellar entry point for accessing the CS utilizing its connection with the inferior intercavernous sinus (IICS) when anatomically present., Methods: The technique for the midline intercavernous dural access is described and depicted with cadaveric dissections and a clinical case., Results: An endoscopic endonasal approach exposed the periosteal dural layer of anterior sella and CS. The IICS was opened sharply in midline through its periosteal layer. The feather knife was inserted and advanced laterally within the IICS toward the anterior CS wall, thereby gradually incising the periosteal layer of the IICS. The knife was turned superiorly then inferiorly in a vertical direction to open the anterior CS wall. This provided excellent access to the CS compartments, maintained the meningeal layer of the IICS and the medial CS wall, and avoided an initial dural incision immediately adjacent to the ICA., Conclusion: The midline intercavernous dural access to the CS assisted by a 90° dissector-blade is an effective modification to previously described techniques, with potentially lower risk to the ICA., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF)., Method: We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video., Conclusion: A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Introduction  Surgery of the sellar and parasellar regions can be challenging due to the complexity of neurovascular relationships. The main goal of this study is to develop an educational resource to help trainees understand the pertinent anatomy and procedural steps of the endoscopic endonasal approaches (EEAs) to the sellar and parasellar regions. Methods  Ten formalin-fixed latex-injected specimens were dissected. Endoscopic endonasal transsphenoidal transsellar, transtuberculum-transplanum, and transcavernous approaches were performed by a neurosurgery trainee, under supervision from the senior authors and a PhD in anatomy with advanced neuroanatomy experience. Dissections were supplemented with representative case applications. Results  Endoscopic endonasal transsphenoidal approaches afford excellent direct access to sellar and parasellar regions. After a wide sphenoidotomy, a limited sellar osteotomy opens the space to sellar region and medial portion of the cavernous sinus. To reach the suprasellar space (infrachiasmatic and suprachiasmatic corridors), a transplanum-prechiasmatic sulcus-transtuberculum adjunct is needed. The transcavernous approach gains access to the contents of the cavernous sinus and both medial (posterior clinoid and interpeduncular cistern) and lateral structures of the retrosellar region. Conclusion  The anatomical understanding and technical skills required to confidently remove skull base lesions with EEAs are traditionally gained after years of specialized training. We comprehensively describe EEAs to sellar and parasellar regions for trainees to build knowledge and improve familiarity with these approaches and facilitate comprehension and learning in both the surgical anatomy laboratory and the operating room., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objective: While pedicled intranasal flaps, such as the nasoseptal flap (NSF), successfully reduce postoperative CSF leaks following endoscopic endonasal approaches (EEA) to the skull base, morbidity remains prevalent. This study describes the first cadaveric description and radiographic analysis of the posterior septal nasal floor mucosal flap (PSNF) designed to reduce pedicled nasal flap morbidity. A case series is also detailed., Study Design: Cadaveric dissection, radiographic analysis, and case series., Methods: Seven cadaver specimens underwent harvest of the PSNF. PSNF flap dimensions were measured on the thirty deidentified sinus computed tomography (CT) scans. A retrospective case series was performed on the first set of patients who received the PSNF for reconstruction of a sellar base defect. Information concerning complications, symptoms, and the appearance of the flap was recorded from records of the patient's postoperative inpatient stay, 1-week postop visit, and 1-month postop visit., Results: Cadaver dissection of the PSNF flap demonstrated good arc rotation along its pedicle with ability to cover both sellar and planum defects. Cadaveric flap measurements and CT-derived measurements estimated a mean surface area of 16.7 and 18.3 cm 2 , respectively. 15 patients underwent reconstruction of a sellar or planum defect using the PSNF technique. Only one CSF leak was encountered postoperatively. Minimal crusting of the flap and donor site was seen 1 month postoperatively., Conclusion: The PSNF flap provides a sizeable pedicled region for reconstruction comparable to other pedicled nasal flaps. Our case series demonstrated good postoperative outcomes without reduced donor site morbidity., Level of Evidence: 4 Laryngoscope, 132:1561-1568, 2022., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Classically, the transtuberculum and transplanum approaches have been utilized to reach the suprachiasmatic and infrachiasmatic corridors. The aim of this study was to provide a better understanding of the key endoscopic endonasal anatomy of the suprachiasmatic and infrachiasmatic corridors provided through selective removal of the prechiasmatic sulcus (SRPS)., Method: A SRPS was performed in 16 sides of 8 alcohol-fixed head specimens. Twenty anatomical measurements were collected on the suprachiasmatic and infrachiasmatic corridors. The transplanum and transtuberculum approaches were also performed., Results: In the suprachiasmatic corridor, the SRPS exposed the anterior communicating artery (AComm) and the post-communicating segment of the anterior cerebral arteries in all the cases, while the pre-communicating segment of the anterior cerebral arteries, recurrent arteries of Heubner, and fronto-orbital arteries were visualized in 75% (12/16), 31% (5/16), and 69% (11/16) of cases, respectively. In the infrachiasmatic corridor, the ophthalmic segment of the internal carotid artery and superior hypophyseal arteries were always visible through the SRPS. The mean width and height of the prechiasmatic sulcus were 13.2 mm and 9.6 mm, respectively. The mean distances from the midpoint of the AComm to the anterior margin of the optic chiasm (OCh) was 5.3 mm. The mean width of the infrachiasmatic corridor was 12.3 mm at the level of the proximal margin of the ophthalmic segment of the internal carotid artery. The mean distances from the posterior superior limit of the pituitary stalk to the basilar tip and oculomotor nerve were 9.7 mm and 12.3 mm, respectively., Conclusions: The SRPS provides access to the main neurovascular and cisternal surgical landmarks of the suprachiasmatic and infrachiasmatic corridors. This anatomical area constitutes the key part of the approach to the suprasellar area. To afford adequate surgical maneuverability, the transplanum or transtuberculum approaches are usually a necessary extension., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Objectives: To demonstrate three-hundred and sixty degrees of maxillary sinus (MS) surgical approaches using cadaveric dissections, highlighting the step-by-step anatomy of each procedure., Methods: Two latex-injected cadaveric specimens were utilized to perform surgical dissections to demonstrate different approaches to the MS. The procedures were documented with macroscopic images and endoscopic pictures., Results: Dissections were performed to approach the MS medially (endoscopic maxillary antrostomy and ethmoidectomy), anteriorly (Caldwell-Luc), superiorly (transconjunctival/transorbital approach), inferiorly (transpalatal approach), and posterolaterally (preauricular hemicoronal approach)., Conclusion: A number of approaches have been described to address pathology in the MS. Surgeons should be familiar with indications, limitations, and surgical anatomy from different perspectives to approach the MS. This paper illustrates anatomic approaches to the MS with detailed step-by-step cadaveric dissections and case examples., Competing Interests: The authors declare that there are no conflict of interests., (© 2022 The Authors. World Journal of Otorhinolaryngology ‐ Head and Neck Surgery published by John Wiley & Sons Ltd on behalf of Chinese Medical Association.)

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., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

The treatment of qualitative olfactory disease is challenging. We aimed to treat parosmia using a new minimally invasive surgical technique-the olfactory cleft blocking technique- by preventing odorants from reaching the olfactory epithelium. A novel surgical procedure for blocking the anterior and inferior openings of the olfactory cleft was accomplished in a patient with unilateral persistent peripheral parosmia. The HRCT and endoscopy were performed preoperatively and postoperatively to evaluate the anatomical structure of the olfactory cleft. The T&T olfactometer was used to assess the preoperative and postoperative olfactory function. After surgery, the patient's parosmia disappeared. Endoscopic examination and CT scan showed complete obstruction of the anterior and inferior portions of the olfactory cleft. No recurrence was reported during a 2-year follow-up. No surgical complications were reported except olfactory loss in the operative nostril. For patients with long-term unilateral peripheral olfactory dysfunction, the olfactory cleft blocking technique seems a novel, simple, safe and effective treatment. Further studies are required with a larger number of patients in order to access success rate., Competing Interests: Declaration of Competing Interest All the authors declare no conflicts of interest in association with the present study., (Copyright © 2020. Published by Elsevier B.V.)

Objective  The jugular foramen is one of the most challenging surgical regions in skull base surgery. With the development of endoscopic techniques, the endoscopic endonasal approach (EEA) has been undertaken to treat some lesions in this area independently or combined with open approaches. The purpose of the current study is to describe the anatomical steps and landmarks for the EEA to the jugular foramen and to compare it with the degree of exposure obtained with the lateral infratemporal fossa approach. Materials and Methods  A total of 15 osseous structures related to the jugular foramen were measured in 33 adult dry skulls. Three silicone-injected adult cadaveric heads (six sides) were dissected for EEA and three heads (six sides) were used for a lateral infratemporal fossa approach (Fisch type A). The jugular foramen was exposed, relevant landmarks were demonstrated, and the distances between relevant landmarks and the jugular foramen were obtained. High-quality pictures were obtained. Results  The jugular foramen was accessed in all dissections by using either approach. Important anatomical landmarks for EEA include internal carotid artery (ICA), petroclival fissure, inferior petrosal sinus, jugular tubercle, and hypoglossal canal. The EEA exposed the anterior and medial parts of the jugular foramen, while the lateral infratemporal fossa approach (Fisch type A) exposed the lateral and posterior parts of the jugular foramen. With EEA, dissection and transposition of the facial nerve was avoided, but the upper parapharyngeal and paraclival ICA may need to be mobilized to adequately expose the jugular foramen. Conclusion  The EEA to the jugular foramen is anatomically feasible but requires mobilization of the ICA to provide access to the anterior and medial aspects of the jugular foramen. The lateral infratemporal approach requires facial nerve transposition to provide access to the lateral and posterior parts of the jugular foramen. A deep understanding of the complex anatomy of this region is paramount for safe and effective surgery of the jugular foramen. Both techniques may be complementary considering the different regions of the jugular foramen accessed with each approach., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Objective  This study was aimed to provide a key update to the seminal works of Prof. Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local improvements in technique, we have developed to optimize efficient neuroanatomic study. Methods  Two formaldehyde-fixed cadaveric heads were injected with colored latex to demonstrate step-by-step specimen preparation for microscopic or endoscopic dissection. One formaldehyde-fixed brain was utilized to demonstrate optimal three-dimensional (3D) photodocumentation techniques. Results  Key steps of specimen preparation include vessel cannulation and securing, serial tap water flushing, specimen drainage, vessel injection with optimized and color-augmented latex material, and storage in 70% ethanol. Optimizations for photodocumentation included the incorporation of dry black drop cloth and covering materials, an imaging-oriented approach to specimen positioning and illumination, and single-camera stereoscopic capture techniques, emphasizing the three-exposure-times-per-eye approach to generating images for HDR postprocessing. Recommended tools, materials, and technical nuances were emphasized throughout. Relative advantages and limitations of major 3D projection systems were comparatively assessed, with sensitivity to audience size and purpose specific recommendations. Conclusion  We describe the first consolidated step-by-step approach to advanced neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof. Rhoton's model can be realized, reproduced, and expanded upon in surgical neuroanatomy laboratories worldwide., Competing Interests: Conflict of Interest L.P.C. reports grants from Mayo Foundation, during the conduct of the study. M.P.C. reports grants from NREF, grants from Medtronic, grants from Storz, grants from CAPES, grants from Mayo Foundation, during the conduct of the study. L.C.P.C.L. reports grants from CAPES, during the conduct of the study.A.P. reports grants from Mayo Clinic, during the conduct of the study. M.J.L. reports grants from Mayo Foundation, during the conduct of the study., (Thieme. All rights reserved.)