BackgroundMiddle turbinate (MT) medialization after endoscopic skull base surgery (ESBS) allows natural positioning of the turbinate, re-opening of the osteomeatal complex, and potential skull base protection from iatrogenic injury by endonasal device insertion. Our institution routinely preserves and medializes the MTs in ESBS by placing bioabsorbable nasal packing in both middle meatuses.ObjectiveThe goal of our study was to use postoperative endoscopic MT scoring to objectively assess the efficacy and durability of our simple technique, in which bioabsorbable nasal packing is placed in both middle meatuses to position the MTs against the septum, following trans-sphenoidal skull base surgery.MethodsA single-center retrospective review was performed of consecutive trans-sphenoidal ESBS patients from 2023 to 2024 to assess postoperative MT positioning. Patients with recorded postoperative nasal endoscopies more than 20 days after surgery were included. Recorded endoscopies were evaluated by 2 independent raters using 2 standardized MT scoring systems assessing station and apposition. An additional subgroup analysis was performed in patients with multiple postoperative endoscopies to assess effect of time on MT position.ResultsFifty patients (100 turbinates) scored by 2 raters were included for a total of 200 turbinate ratings. One hundred ninety-two turbinates (96%) had station assessed as 1+, signifying medialization, and 176 turbinates (88%) demonstrated direct apposition to the septum. Nasal endoscopies were analyzed 43.5 days (median) after surgery. Cohen's kappa coefficient was 0.90 for station and 0.63 for apposition, signifying substantial inter-rater reliability. Subgroup analysis demonstrated no significant effect of time on turbinate station or apposition.ConclusionsOur experience with bioabsorbable nasal packing in the middle meatus demonstrates that a simple technique can achieve durable MT medialization in many patients following ESBS. Optimizing MT positioning can improve postoperative sinus function and help protect against inadvertent skull base injuries in ESBS patients.

Despite advances in endoscopic skull base surgery, postoperative sinonasal inflammation remains poorly characterized. In particular, sphenoid sinus osteitis has received little attention, as complications after endoscopic transsphenoidal surgery (ETS) have largely been assessed in terms of mucosal pathology. This study aims to determine the incidence of sphenoid sinus osteitis after ETS, describe its clinical and radiological features, and identify associated surgical and demographic risk factors. We retrospectively reviewed patients undergoing primary ETS for sellar or parasellar tumors between September 2021 and September 2024. Osteitis was assessed on high-resolution CT using the Lee and Kennedy classification. Clinical symptoms, particularly cacosmia, and surgical approach and reconstruction techniques were analyzed as potential risk factors. Among 1,443 patients, sphenoid sinus osteitis was identified in 12 cases (0.83%).All cases occurred in patients who underwent sellar reconstruction, with no osteitis observed in those without reconstruction (p < 0.001).Regarding reconstruction techniques, the nasoseptal flap showed a borderline statistical significance (p = 0,045).Radiologically, osteitis was Grade 1 in 50%, Grade 2 in 25%, and Grade 3 in 25% of cases.Cacosmia was the presenting symptom in 75% of affected patients (p < 0.001). Surgical revision was required in 11 patients (91.7%), while medical treatment alone was sufficient in one case. At the 12-month follow-up, all of the patients were symptom-free; one patient required a second revision for recurrent sphenoid sinusitis at sixth months follow up. Sphenoid sinus osteitis represents a rare but clinically relevant bone-centered complication following ETS, distinct from conventional rhinonasal morbidity. Its exclusive association with sellar reconstruction highlights the potential role of reconstruction-related bone contact and localized inflammatory responses in its pathogenesis. Recognizing sphenoid sinus osteitis as a distinct postoperative entity may improve diagnostic accuracy and guide more targeted management of postoperative rhinonasal symptoms. Surgical revision served as the primary intervention for the patient cohort, yielding favorable outcomes characterized by complete symptomatic resolution at the 12-month follow-up.

Despite the success of the endoscopic endonasal approach, ergonomic and workflow challenges require surgeons to operate outside their direct line of sight using nonsterile 2-dimensional (2D) planar displays. Mixed reality (MR) may address these limitations by unifying video feeds and imaging into a heads-up display; however, its role during intraoperative streaming remains unclear. The objective of this study was to evaluate the performance, usability, and ergonomics of MR compared with 2D planar displays during endoscopic skull base surgeries in cadaveric models. Four skull base neurosurgeons from a single institution each conducted 4 cadaveric trials of endonasal endoscopic skull base dissections, 2 with a 2D planar display and 2 with an MR-streaming interface (HoloLens 2). Surgical performance was evaluated through (1) an objective error analysis performed by a neurosurgeon blinded to the display type and (2) a blinded video condition recognition survey distributed to skull base surgery experts and nonexperts. MR-streaming interface usability and ergonomics were evaluated through post-trial Surgical Task Load Index scores and Simulator Sickness Questionnaire, respectively. An objective error analysis revealed that the total number of errors encountered between MR-streaming and 2D planar display conditions was comparable within the limits of this sample (P = .73). Subgroup analysis per error type further demonstrated no significant differences for all examined errors. Survey responses showed no significant difference in the experts' and nonexperts' abilities to distinguish between MR-streaming and 2D planar display conditions (P = .90). MR-streaming was associated with reduced task load compared with current literature. Finally, MR-streaming had ergonomic shortcomings such as general discomfort, eyestrain, and difficulty concentrating. MR-streaming provides comparable surgical task performance compared with 2D planar displays during cadaveric endoscopic skull base surgeries. With further user experience and latency improvements, this novel method provides a promising pathway toward a digital operating room environment.

Introduction The anterior clinoid process (ACP) is a critical anatomical landmark during skull base surgery. However, ACP pneumatization poses several risks during anterior clinoidectomy, including cerebrospinal fluid (CSF) leakage and optic nerve injury. Existing classification systems inadequately address clinically significant variations such as those involving the optic strut or planum sphenoidale. Therefore, this study aimed to determine the prevalence and morphological patterns of ACP pneumatization in a Thai population and propose a refined radiological classification system based on the route and extent of pneumatization. Methods A retrospective computed tomography (CT)-based study was conducted on 400 ACPs from 200 patients aged ≥10 years. Pneumatization patterns were categorized into eight subtypes based on the pneumatization route (optic strut, planum sphenoidale, or both) and the degree of ACP involvement (≤50% or &amp;gt;50%). ACP morphometric data and associated bone variations were also assessed. Results ACP pneumatization was observed in 30.8% of ACPs, with bilateral involvement in 5% of cases. The most frequent subtype was isolated optic strut pneumatization (subtype 1, 16%), followed by limited ACP involvement via the optic strut (subtype 2a, 6%). Planum-based and combined subtypes (3a and 4b) were uncommon (&amp;lt;4%). Male patients demonstrated significantly greater ACP base width (9.09 ± 1.61 mm vs. 8.54 ± 1.39 mm; p = 0.015) and length (13.23 ± 1.72 mm vs. 12.61 ± 1.64 mm; p = 0.010) than females. Middle clinoid processes and interclinoid calcifications were present in 5.8% and 8.8% of patients, respectively. Conclusion ACP pneumatization, particularly via the optic strut, is a common anatomical variation. The proposed eight-subtype classification provides a nuanced framework for preoperative imaging description and communication. Although prior classifications were largely discussed in the context of transcranial approaches, the observed pneumatization patterns may also be relevant to endoscopic endonasal anatomy, particularly regarding optic canal exposure and potential sinonasal communication. Prospective surgical correlation studies are warranted to determine concordance with intraoperative findings and to clarify clinical relevance.

BACKGROUND Sneeze suppression creates a sudden pressure change that forces air or fluid through the weak points in the sinonasal walls - either the skull base or orbit - potentially leading to a cerebrospinal fluid (CSF) leak and pneumocephalus, both of which can resolve with conservative care. Spontaneous CSF leaks are often overlooked in patients without a history of trauma or prior skull base surgery. CASE REPORT A 45-year-old woman with no history of trauma or surgery presented with a 3-month history of recurrent headaches and clear nasal discharge from the left side. Upon further questioning, she admitted to frequently suppressing sneezing, particularly in public. Imaging studies revealed additional sinonasal abnormalities, a defect in the left cribriform plate, and scattered pneumocephalus. No evidence of infection or neoplastic pathology was identified. She underwent successful endoscopic skull base repair after conservative treatments failed. Postoperatively, she was advised to avoid activities associated with increased intranasal pressure. She was treated with acetazolamide, which was later discontinued. She experienced complete symptom relief and a successful surgical outcome over 1 year of follow-up. CONCLUSIONS This case study emphasizes sneeze suppression as a rare but clinically significant cause of pneumocephalus and spontaneous cerebrospinal fluid leak. In the absence of trauma or previous surgery, patients presenting with unexplained rhinorrhea or intracranial air may benefit from an earlier diagnosis if this mechanism is recognized. Early radiological evaluation plays a crucial role in identifying skull base defects and guiding management. Potentially dangerous complications could be avoided with patient education and clinician awareness of safe sneezing techniques.

The anterior transpetrosal approach (ATPA) is one of the useful methods for targeting the middle clival and ventrolateral pontine areas. Thanks to the advances in endoscopic skull base surgery, there have been increased attempts to perform anterior petrosectomy via the endoscopic transorbital approach (ETOA), although some limitations and drawbacks have also been suggested. This study aimed to analyze the contribution of the endoscopic biportal transorbital technique to anterior petrosectomy. A total of ten cadaveric heads (twenty sides) were dissected at the Surgical Neuroanatomy Laboratory. The biportal ETOA was established by combining the main transorbital port with an accessory lateral orbital port created beyond the lateral orbital rim. In each head, anterior petrosectomy through uniportal ETOA was performed on one side, followed by the biportal ETOA on the same side, while the transcranial subtemporal ATPA was done on the other side. The extent of exposure for each approach was documented using representative photographs obtained during dissection. The angle of attack (AOA) was measured at key surgical landmarks, including Meckel's cave, the root entry zone (REZ) of cranial nerves V, VI, VII, and VIII, and the internal acoustic porus. The drilled volume of the petrous apex was calculated by comparing pre- and post-dissection CT scans. By utilizing the accessory port, it was possible to obtain a more medial trajectory, allowing wider exposure of CN V, CN VI, CN VII, CN VIII, and the ventrolateral pons than the uniportal approach. The angle of attack (AOA) increased with the biportal transorbital approach compared to the uniportal route by approximately 26.1-46.7% in the horizontal axis, 21.6-52.4% in the vertical axis. When measuring the drilled volume of the petrous apex, no statistically significant difference was observed between the biportal ETOA and the traditional transcranial craniotomy method. (0.9339 ± 0.1037 vs 0.9729 ± 0.0692 cm3, p = 0.067). This study demonstrates that the biportal ETOA can compensate for the limitations of the uniportal approach in performing anterior petrosectomy by providing a wider field of view and greater surgical freedom.m neurodevelopmental outcomes in vulnerable pediatric neurosurgical patients.

Endoscopic sinus and skull base surgery has evolved significantly with advances in visualization and powered instrumentation, aiming to improve surgical precision while minimizing complications. Among these innovations, piezoelectric devices represent a valuable addition to modern rhinologic and skull base surgery. This review highlights the principles, mechanisms, and clinical applications of piezoelectric technology in endoscopic sinus and skull base procedures. Piezoelectric devices operate through ultrasonic microvibrations that selectively cut mineralized tissue while preserving adjacent soft tissues such as dura, nerves, blood vessels, and the Schneiderian membrane. This selective action enhances surgical safety, particularly when operating near critical structures including the orbit, optic nerve, internal carotid artery, and anterior skull base. Compared with conventional drills and curettes, piezosurgery provides improved surgical control, reduced bleeding, enhanced visibility, and lower risk of thermal and mechanical injury. Clinical applications include removal of thick bony partitions, skull base osteotomies, optic nerve decompression, management of fibro-osseous lesions, and assistance in endoscopic tumor surgery. Histological and experimental studies suggest improved bone healing and preservation of osteocyte viability following piezoelectric osteotomy. Despite its advantages, piezosurgery is associated with higher cost, longer operative time, and a learning curve that may limit widespread adoption. In conclusion, piezoelectric technology offers a safe and precise alternative to conventional bone-cutting instruments in endoscopic sinus and skull base surgery, particularly in anatomically high-risk areas. Further clinical studies are warranted to better define its cost-effectiveness and long-term outcomes.

Electroconvulsive therapy (ECT) after skull-base reconstruction poses safety concerns related to potential elevations in intracranial pressure (ICP) and the risk of graft disruption. We report the case of a 61-year-old man with bipolar I depression who successfully underwent a course of right-unilateral brief-pulse ECT 7 weeks after transmastoid hydroxyapatite cement repair of a 1.5-cm tegmen mastoideum defect associated with cerebrospinal fluid (CSF) otorrhea. After initiation of ECT, the patient demonstrated marked clinical improvement [Montgomery-Åsberg Depression Rating Scale (MADRS) score reduced from 32 to 6 after 8 treatments], maintained stable cognition, and experienced no otologic or neurologic complications. This case illustrates that, with interdisciplinary collaboration and confirmation of postoperative graft integrity, ECT can be safely initiated in the early postoperative period after skull-base surgery.

Many studies have focused on Gruber's ligament and Dorello's canal. However, only scant studies have analyzed these structures via histological analysis. Furthermore, the histology studies for these structures did not sufficiently evaluate them and their surrounding anatomical relationships. Therefore, this study aims to assess the comprehensive morphology of Gruber's ligament and Dorello's canal. Histological observation in coronal and sagittal sections and microsurgical observations (using both conventional and inferior approaches) were conducted on Gruber's ligament, Dorello's canal, and related structures. Histological observation revealed that the only extension of the dura was found between the petrous apex and the clivus. Microsurgical dissection using the conventional approach identified a fibrous band, whereas the inferior approach did not reveal any distinct connective tissue other than dura. Our multidirectional approach demonstrated that Gruber's ligament is part of the dura between the petrous apex and clivus. The petrous apex end was artificially separated from the dura along the medial wall of the cavernous sinus. The previously reported variations of Gruber's ligament, such as duplication or absence, can now be explained by our findings. Gruber's ligament is simply a part of the dura at the skull base. The extension of the dura between the petrous apex and clivus, which forms part of a mesh-like structure rather than a distinct ligament, traditionally has been termed Gruber's ligament.

Facial nerve preservation is critical in skull base surgery. Transcranial facial motor-evoked potential (tfMEP) monitoring can be limited by interindividual primary motor cortex (M1) facial cortex variability and intraoperative perturbations. We evaluated a functional MRI (fMRI)-guided, neuronavigation-assisted montage to personalize stimulating electrode placement and reduce thresholds during cerebellopontine angle tumor surgery. In a prospective cohort (n = 20), tfMEPs were recorded simultaneously using 2 montages: (1) fMRI-guided electrode directly over the patient-specific M1 facial hotspot identified by preoperative task fMRI and (2) conventional C3/C4. Train-of-five stimulation elicited compound muscle action potentials from orbicularis oculi/oris. The primary end point was stimulation threshold (mA) to elicit >50 µV, measured at predefined stages (precraniotomy through closure). Secondary analyses assessed threshold changes after durotomy/cerebrospinal fluid (CSF) drainage and postoperative House-Brackmann (HB) grades. fMRI-guided placement yielded lower baseline thresholds than conventional within patients (mean 65.5 vs 73.5 mA; Δ = -8.9 mA; P < .0001). The advantage persisted at closure (85.3 vs 96.3 mA; P < .0001). After durotomy/CSF drainage, thresholds increased modestly with both montages (+3.3 vs +4.0 mA; between-group P = .65). Monitoring feasibility was 100%, providing continuous data early in the case when direct nerve stimulation was not yet possible. At the latest follow-up, 17/20 (85%) had HB I and 3/20 (15%) HB II; no patient had permanent moderate/severe palsy. Neuronavigation-assisted, fMRI-guided tfMEP reliably targets the individual M1 facial area and significantly lowers stimulation thresholds vs conventional C3/C4, without increasing susceptibility to threshold drift after CSF loss. This simple, adoptable workflow may enhance intraoperative decision making for facial nerve preservation. Larger multicenter studies are warranted to validate outcome prediction and refine threshold-based alarm criteria.

Abstract To characterize contemporary management strategies and reconstructive techniques for frontal bone osteoradionecrosis (ORN) following anterior skull base surgery and radiation therapy (RT). Retrospective case series. Tertiary academic medical center. Patients who underwent craniotomies for anterior skull base tumors between 2008 and 2023 and received postoperative RT. Incidence, timing, and management of frontal bone ORN, including reconstructive approaches and surgical outcomes. Among 39 patients meeting inclusion criteria, 7 (18%) developed frontal bone ORN after anterior skull base surgery and radiation. All affected patients received adjuvant radiation with a mean cumulative dose of 67.2 Gy (range, 62.4–69.6). ORN was diagnosed at a mean of 28.7 months (range, 2–78) following completion of radiation therapy. Five patients (71%) underwent surgical intervention, which universally included debridement and hardware removal. Reconstructive strategies comprised temporalis muscle flap (20%), titanium cranioplasty (60%), free flap reconstruction (60%), and custom-designed cranial implants (60%). Primary free flaps included radial forearm (n = 2) and latissimus dorsi (n = 1), with two patients later requiring anterolateral thigh flaps. Median follow-up was 10 years (range, 6.7–14.3), during which patients underwent a median of 2.5 reconstructive procedures (range, 0–6). Management of frontal bone ORN often requires complex revision cranioplasty and free flap reconstruction. Most patients required multiple surgeries to achieve stable wound healing, underscoring the importance of early recognition and consideration of prophylactic strategies in high-risk, irradiated patients. 4.

Free-hand electrode placement for intraoperative monitoring of extraocular cranial nerves in skull base surgery: preliminary experience and feasibility assessment.

The endoscopic endonasal approach (EEA) to the skull base has revolutionized the management of ventral skull base lesions, offering superior visualization and reduced morbidity. Yet, iatrogenic cranial nerve (CN) injuries, causing temporary or permanent deficits, remain an underexplored complication that significantly affects quality of life. This systematic review describes the number of reported cases of CN injuries in EEA and the evidence on prevention and management strategies. Following PRISMA-SR guidelines, we searched Medline, Embase, Web of Science, and the Cochrane Library, and screened 2796 studies; 177 were included. Across 18,546 patients, 859 CN injuries were reported. The abducens (24.4%), optic (23.7%), and olfactory (18.6%) nerves were most affected, linked primarily to pituitary adenomas (34.49%) and sellar approaches (34.4%). Full recovery occurred in 38.4% of cases, while 29.9% had permanent deficits. Intraoperative neuromonitoring was reported in 34 studies, showing prognostic value but lacking definitive evidence for injury prevention. Only 5% of studies addressed postoperative management, highlighting a care gap. This review emphasizes the need for standardized reporting, enhanced monitoring, and robust postoperative strategies to optimize EEA outcomes. Future directions include prospective studies and patient-reported outcomes to refine skull base surgery safety.

Lateral Skull Base Pseudomeningoceles: Diagnosis, Prevention, and Treatment.

Single-layer Endoscopic Repair of Anterior Skull Base Defects.

The anterior skull base forms the bony floor of the anterior cranial fossa and serves as a barrier between the sinuses and nasal cavity and the brain. The most common pathologies in this area include tumors (benign and malignant), inflammatory and infectious diseases, congenital anomalies, and traumatic injuries. Anterior skull base surgeries are performed as part of a multidisciplinary team effort. In the past, these surgeries were performed using open approaches, but with the advancement of endoscopic technology, most surgeries are now performed using minimally invasive techniques, improving recovery and reducing complications. To provide a descriptive review of all anterior skull base surgeries performed using endoscopic or combined approaches at Shaare Zedek Medical Center from the department's establishment until the end of 2024. The study was based on data collection from all surgeries recorded in the database of the Shaare Zedek Medical Center. Between the years 2017 and 2024, a total of 177 anterior skull base surgeries were performed, including 163 for primary pathologies and 14 revision surgeries. Postoperative CSF leak occurred in 5.5% of patients, and symptomatic residual tumors were observed in 3%. Most surgeries were performed using the endoscopic approach, except in cases of extensive bony deficiency or intracranial involvement, where a combined approach was used. The transition from open to endoscopic approaches has led to significant improvements in managing anterior skull base surgeries. However, in selected cases, the combined approach offers advantages by integrating open and endoscopic techniques. Multidisciplinary expertise contributes to the success of these surgeries and minimizes complications. The endoscopic approach to the anterior skull base represents a breakthrough in treating complex pathologies in this region. The integration of the combined approach in complex cases enables optimal treatment while maintaining minimally invasive principles. The use of advanced techniques and multidisciplinary collaboration improves the quality of care and reduces the risk of complications.

Anatomical variations of the clivus and related craniometric measurements in the adult population of Botswana: A CT-Based study

To investigate the factors that influence subspecialty preferences among neurosurgery trainees in the Andean Community of Latin America and to assess how educational interventions affect subspecialty choices. A total of 132 neurosurgery residents and young practicing neurosurgeons participated in the study. Participants completed surveys before and after educational interventions that included hands-on training, lectures, and online resources. Basic demographic data were collected through an electronic survey, which also included questions regarding participants' desired future subspecialty, including cerebrovascular and skull base (CV/SB) surgery, spine surgery, trauma, pediatric surgery, pain surgery, or neuro-oncology and preferred location of practice, including capital city, urban area, or rural area. Changes in subspecialty preferences and desired locations of practice before and after the intervention were analyzed statistically to assess the correlation between educational interventions and career aspirations. Before the intervention, 91.0% of participants (120 of 132) expressed interest in cranial subspecialties (CV/SB surgery and neuro-oncology), primarily CV/SB surgery. After the intervention, there was a significant shift in subspecialty interest, with 67% expressing a preference for CV/SB surgery (P < .01, 95% CI: 9.2%-32.8%). Notably, hands-on training was the only intervention that significantly altered participants' subspecialty preferences (r = -0.52; P < .01, 95% CI: -0.63 to -0.38). In addition, 69% preferred practicing in capital cities, with a strong correlation between practice location and subspecialty desire (r = 0.49; P < .01, 95% CI: 0.35-0.61). This study highlights the importance of targeted educational interventions in shaping neurosurgery trainees' subspecialty preferences in the Andean Community. There is a clear inclination toward cranial subspecialties after the educational interventions, particularly CV/SB surgery. Understanding these dynamics is crucial for addressing the lack of neurosurgeons in Latin America and for optimizing resource allocation for residency programs.

The anterior transpetrosal approach (ATPA) is the standard technique for treating lesions around the petrous apex. Conventional microscopic ATPA is associated with limited linear visibility and enhanced risks related to temporal lobe retraction. This article reviewed endoscopic ATPA (eATPA) and addressed some of the limitations. The eATPA utilizes a panoramic endoscopic view through a small craniotomy, significantly reducing the need for brain retraction and eliminating blind spots in the ventral brainstem. The procedure centers on precise extradural drilling of Kawase's triangle. The primary indications include small petroclival meningiomas, dumbbell-shaped trigeminal schwannomas, and epidermoid cysts. This review detailed the surgical anatomy, operative nuances, and strategies for avoiding critical complications, specifically venous congestion, regarding the superficial middle cerebral vein, superior petrosal vein, and cerebrospinal fluid leakage. Although currently indicated for small lesions, eATPA is a minimally invasive skull base surgery. eATPA is a vital component of future multicorridor strategies, offering safer, tailor-made treatments for complex skull base pathologies when combined with endovascular or transnasal approaches.

Endoscopic transsphenoidal surgery has been the most commonly performed neuroendoscopic procedure in Japan since its reimbursement category was introduced in 2012. Although the surgical technique is now largely standardized, perioperative management and operating room setup still vary among institutions. At our center, patients are positioned in a semi-Fowler's posture with the head elevated to reduce venous bleeding from the cavernous sinus, while carefully monitoring the risk of venous air embolism. A slight vertex-up angle facilitates a natural instrument trajectory and is adjusted according to lesion location. Surgery is performed using a four-hand technique, with the assistant controlling the endoscope and coordinating movements with the surgeon, adapting to anatomical constraints and the use of straight or angled endoscopes. We also describe our approach to perioperative glucocorticoid supplementation, postoperative endocrine management for pituitary disorders, and the prevention and treatment of delayed postoperative hyponatremia. Collaboration with otolaryngologists is preferred for postoperative nasal care. These strategies aim to enhance surgical safety, infection control, endocrine stability, and patient comfort while supporting continued advances in endoscopic skull base surgery.