Trigeminal Microvascular Decompression and Meckel's Cave Tumor Resection via Retrosigmoid Approach With Suprameatal Extension: 2-Dimensional Operative Video.

The leading cause of trigeminal neuralgia (TGN) relies on the microvascular conflict between the superior cerebellar artery (SCA) loop and the dorsal root entry zone of the trigeminal nerve (TN). However, lesions along the TN have been described as a possible cause of TGN for direct mass effect or indirect vascular transposition. Thus, the surgical approach to TGN in patients harboring cerebellopontine angle or Meckel's cave tumor should be methodically chosen. The retrosigmoid (RS) approach with suprameatal extension offers direct access to the TN in both its cisternal and Meckel's cave segment, allowing optimal TN decompression from vascular and tumoral components. Although the RS approach with suprameatal extension has been described in numerous studies,1-4 videos detailing its key steps in addressing a multicomponent TGN are lacking. In this video, we highlight the case of a 46 year-old woman with 6 months of medically refractory typical TGN with a right en plaque meningioma involving the petrous bone, petroclival junction, Meckel's cave, and tentorium. In addition, magnetic resonance imaging was suspicious for a compressive SCA loop over the dorsal root entry zone. The patient underwent a RS approach with suprameatal extension for subtotal resection of the tumor and microvascular decompression of the TGN. The patient recovered with no complications and TGN resolved.

A Cadaveric Feasibility Study of the Biportal Endoscopic Transfrontal Sinus Approach: A Minimally Invasive Approach to the Anterior Cranial Fossa.

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.

Endoscopic-assisted transorbital extended orbital exenteration: A multi-institutional preclinical study.

BACKGROUND: Sinonasal malignancies with orbital invasion have dismal prognosis even when treated with orbital exenteration (OE). Sugawara et al. developed a surgical strategy called "extended-OE (EOE)," showing encouraging outcomes. We hypothesized that a similar resection is achievable under endoscopic guidance through the exenterated orbit (endoscopic-EOE). METHODS: The study was conducted in three institutions: University of Vienna; Mayo Clinic; University of Insubria; 48 orbital dissections were performed. A questionnaire was developed to evaluate feasibility and safety of each step, scoring from 1 to 10, ("impossible" to "easy," and "high risk" to "low risk," respectively), most likely complication(s) were hypothesized. RESULTS: The step-by-step technique is thoroughly described. The questionnaire was answered by 25 anterior skull base surgeons from six countries. Mean, median, range, and interquartile range of both feasibility and safety scores are reported. CONCLUSIONS: Endoscopic-EOE is a challenging but feasible procedure. Clinical validation is required to assess real-life outcomes.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Frontotemporal and Orbitozygomatic Craniotomies.

Introduction Although many neuroanatomic atlases have been published, few have detailed complex cranial approaches and pertinent anatomic considerations in a stepwise fashion intended for rapid comprehension by neurosurgery students, residents, and fellows. Methods Five sides of formalin-fixed latex-injected specimens were dissected under microscopic magnification. The frontotemporal and orbitozygomatic approaches were performed by neurosurgical residents and fellows at different training levels with limited previous experience in anatomical dissection mentored by the senior authors (M.P.C. and M.J.L.). Meticulous surgical anatomic dissections were performed until sufficient visual and technical completion was attained, with parameters of effectively demonstrating key surgical steps for educational training purposes. Following the completion of dissection and three-dimensional photography, illustrative case examples were reviewed to demonstrate the relative benefits and optimal applications of each approach. Results The frontotemporal and orbitozygomatic approaches afford excellent access to anterior and middle skull base pathologies, as well as the exposure of the infratemporal fossa. Key considerations include head positioning, skin incision, scalp retraction, fat pad dissection and facial nerve protection, true or false MacCarty keyhole fashioning, sphenoid wing drilling and anterior clinoidectomy, completion of the craniotomy and accessory orbital osteotomy cuts, dural opening, and intradural neurovascular access. Conclusion The frontotemporal and orbitozygomatic approaches are core craniotomies that offer distinct advantages for complex cranial operations. Learning and internalizing their key steps and nuanced applications in a clinical context is critical for trainees of many levels. The orbitozygomatic craniotomy in particular is a versatile but challenging approach; operative-style laboratory dissection is an essential component of its mastery and one that will be powerfully enhanced by the current work.

The Coexistence of Carotico-Clinoid Foramen and Interclinoidal Osseous Bridge: An Anatomo-Radiological Study With Surgical Implications.

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.

Multi-center study on sellar reconstruction after endoscopic transsphenoidal pituitary surgery.

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.

Photogrammetry scans for neuroanatomy education - a new multi-camera system: technical note.

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.

3D Models as a Source for Neuroanatomy Education: A Stepwise White Matter Dissection Using 3D Images and Photogrammetry Scans.

White matter dissection (WMD) involves isolating bundles of myelinated axons in the brain and serves to gain insights into brain function and neural mechanisms underlying neurological disorders. While effective, cadaveric brain dissections pose certain challenges mainly due to availability of resources. Technological advancements, such as photogrammetry, have the potential to overcome these limitations by creating detailed three-dimensional (3D) models for immersive learning experiences in neuroanatomy. This study aimed to provide a detailed step-by-step WMD captured using two-dimensional (2D) images and 3D models (via photogrammetry) to serve as a comprehensive guide for studying white matter tracts of the brain. One formalin-fixed brain specimen was utilized to perform the WMD. The brain was divided in a sagittal plane and both cerebral hemispheres were stored in a freezer at -20 °C for 10 days, then thawed under running water at room temperature. Micro-instruments under an operating microscope were used to perform a systematic lateral-to-medial and medial-to-lateral dissection, while 2D images were captured and 3D models were created through photogrammetry during each stage of the dissection. Dissection was performed with comprehensive examination of the location, main landmarks, connections, and functions of the white matter tracts of the brain. Furthermore, high-quality 3D models of the dissections were created and housed on SketchFab®, allowing for accessible and free of charge viewing for educational and research purposes. Our comprehensive dissection and 3D models have the potential to increase understanding of the intricate white matter anatomy and could provide an accessible platform for the teaching of neuroanatomy.

Predicting the Need for Occipitocervical Fusion for Patients with Lower Clival Chordoma: A Single-Center Retrospective Study.

OBJECTIVE: To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF). METHODS: A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging. RESULTS: Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (P = 0.006), ligament absence (P = 0.022), and increased propensity for postoperative wound issues (P = 0.022) than the non-OCF group. The OCF group had less intact OCs (P < 0.001) and higher spinal instability neoplastic score (P = 0.002) than the non-OCF group. All patients with intact OCs < 60% underwent OCF, and those with OCs ≥ 70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach alone being common. Radiation therapy was administered to 89% of patients. All 3 patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups. CONCLUSIONS: In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC ≥ 60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

360 Degrees Endoscopic Access to and Through the Orbit.

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Comparative Efficacy of Transsphenoidal and Transcranial Approaches for Treating Tuberculum Sellae Meningiomas: A Systematic Review and Meta-Analysis.

Background/Objectives: Tuberculum sellae meningiomas (TSMs) constitute 5-10% of intracranial meningiomas, often causing visual impairment. Traditional microsurgical transcranial approaches (MTAs) have been effective, but the emergence of innovative surgical trajectories, such as endoscopic endonasal approaches (EEAs), has sparked debate. While EEAs offer advantages like reduced brain retraction, they are linked to higher cerebrospinal fluid leak (CSF leak) risk. This meta-analysis aims to comprehensively compare the efficacy and safety of EEAs and MTAs for the resection of TSMs, offering insights into their respective outcomes and complications. Methods: A comprehensive literature review of the databases PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted for articles published on TSMs treated with either EEA or MTA until 2024. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analysis was performed to estimate pooled event rates and assess heterogeneity. Fixed- and random-effects were used to assess 95% confidential intervals (CIs) of presenting symptoms, outcomes, and complications. Results: A total of 291 papers were initially identified, of which 18 studies spanning from 2000 to 2024 met the inclusion criteria. The exclusion of 180 articles was due to reasons such as irrelevance, non-reporting of selected results, systematic literature review or meta-analysis, and a lack of details on method/results. The 18 studies comprised a total sample of 1093 patients: 444 patients who underwent EEAs and 649 patients who underwent MTAs for TSMs. Gross total resection (GTR) rates ranged from 80.9% for EEAs to 79.8% for MTAs. The rate of visual improvement was 86.6% in the EEA group and 65.4% in the MTA group. The recurrence rate in the EEA group was 6.9%, while it was 5.1% in MTA group. The postoperative complications analyzed were CSF leak, infections, dysosmia, intracranial hemorrhage (ICH), and endocrine disorders. The rate of CSF leak was 9.8% in the EEA group and 2.1% in MTA group. The rate of infections in the EEA group was 5.7%, while it was 3.7% in the MTA group. The rate of dysosmia ranged from 10.3% for MTAs to 12.9% for EEAs. The rate of ICH in the EEA group was 0.9%, while that in the MTA group was 3.8%. The rate of endocrine disorders in the EEA group was 10.8%, while that in the MTA group was 10.2%. No significant difference was detected in the rate of GTR between the EEA and MTA groups (OR 1.15, 95% CI 0.7-0.95; p = 0.53), while a significant benefit in visual outcomes was shown in EEAs (OR 3.54, 95% CI 2.2-5.72; p < 0.01). There was no significant variation in the recurrence rate between EEA and MTA groups (OR 0.92, 95% CI 0.19-4.46; p = 0.89). While a considerably increased chance of CSF leak from EEAs was shown (OR 4.47, 95% CI 2.52-7.92; p < 0.01), no significant difference between EEA and MTA groups was detected in the rate of infections (OR 1.92, 95% CI 0.73-5.06; p = 0.15), the rate of dysosmia (OR 1.25, 95% CI 0.31-4.99; p = 0.71), the rate of ICH (OR 0.61, 95% CI 0.20-1.87; p = 0.33), and the rate of endocrine disorders (OR 1.16, 95% CI 0.69-1.95; p = 0.53). Conclusions: This meta-analysis suggests that both EEAs and MTAs are viable options for TSM resection, with distinct advantages and drawbacks. The EEAs demonstrate superior visual outcomes in selected cases while GTR and recurrence rates support the overall effectiveness of MTAs and EEAs. Endoscopic endonasal approaches had a higher chance of CSF leaks, but there are no appreciable variations in other complications. These results provide additional insights regarding patient outcomes in the intricate clinical setting of TSMs.

360° around the orbit: key surgical anatomy of the microsurgical and endoscopic cranio-orbital and orbitocranial approaches.

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.

Extraocular muscle electromyographic recordings for intraoperative monitoring of cranial nerves III, IV, and VI: a single-center experience with intraorbital electrodes.

OBJECTIVE: The objective of this study was to describe the quantitative features of intraoperative electromyographic recordings obtained from cranial nerve III, IV, and VI neuromonitoring using 25-mm intraorbital electrodes, in the larger context of demonstrating the practicality of this technique during neurosurgical cases. METHODS: A 25-mm-long shaft-insulated intraorbital needle electrode is routinely used at the authors' institution for extraocular muscle (EOM) electromyographic monitoring of the inferior rectus, superior oblique, and/or lateral rectus muscles when their function is at risk. Cases monitored between January 1, 2021, and December 31, 2022, were reviewed for patient demographics, tumor location and pathology, EOMs monitored, pre- and postoperative examination, and complications from electrode placement. Compound muscle action potentials on triggered electromyography, as well as neurotonic discharges on free-run electromyography, were described quantitatively. RESULTS: There were 141 cases in 139 patients reviewed during the 24-month time span, with 278 EOMs monitored (inferior rectus/superior oblique/lateral rectus muscles 68/68/142). Triggered electromyography yielded biphasic or triphasic compound muscle action potentials from EOMs with a mean onset latency of 1.51 msec (range 0.94-3.22 msec), mean maximal peak-to-trough amplitude of 1073.93 µV (range 76.75-7796.29 µV), and high specificity for the channel in nearly all cases. Neurotonic discharges were recorded in 30 of the 278 EOMs (with all 3 muscles represented) and associated with a greater incidence of new or worsened ophthalmoparesis (OR 4.62, 95% CI 1.3-16.4). There were 2 cases of small periorbital ecchymosis attributed to needle placement; additionally, 1 case of needle-related intraorbital hematoma occurred after the review period. CONCLUSIONS: The 25-mm shaft-insulated intraorbital electrode facilitates robust and consistent electromyographic recordings of EOMs that are advantageous over existing techniques. Combined with the relative ease of needle placement and low rate of complications, the technique is practical for neuromonitoring during craniotomies.

Treatment modalities and outcomes of granular cell tumors and spindle cell oncocytomas of the pituitary gland: an analysis of two national cancer databases.

BACKGROUND: Spindle cell oncocytomas (SCO) and granular cell tumors (GCT) are rare primary pituitary neoplasms; the optimal treatment paradigms for these lesions are unknown and largely unexplored. Thus, using national registries, we analyze the epidemiology, management patterns, and surgical outcomes of SCOs and GCTs. METHODS: The National Cancer Database (NCDB; years 2003-2017) and the Surveillance, Epidemiology, and End Results Program (SEER; years 2004-2018) were queried for patients with pituitary SCOs or GCTs. Incidence, extent of surgical resection, and rate of postoperative radiation use for subtotally resected lesions comprised the primary outcomes of interest. All-cause mortality was also analyzed via time-to-event Kaplan-Meier curves. RESULTS: SCOs and GCTs have an annual incidence of 0.017 and 0.023 per 1,000,000, respectively. They comprise 0.1% of the benign pituitary tumors registered in NCDB. A total of 112,241 benign pituitary tumors were identified in NCDB during the study period, of which 83 (0.07%) were SCOs and 59 (0.05%) were GCTs. Median age at diagnosis was 55 years, 44% were females, and median maximal tumor diameter at presentation was 2.1 cm. Gross total resection was achieved in 54% patients. Ten patients (7%) had postoperative radiation. Comparing patients with GCTs versus SCOs, the former were more likely to be younger at diagnosis (48.0 vs. 59.0, respectively; p < 0.01) and female (59% vs. 34%, p = 0.01). GCTs and SCOs did not differ in terms of size at diagnoses (median maximal diameter: 1.9 cm vs. 2.2 cm, respectively; p = 0.59) or gross total resection rates (62% vs. 49%, p = 0.32). After matching SCOs and GCTs with pituitary adenomas on age, sex, and tumor size, the former were less likely to undergo gross total resection (53% vs. 72%; p = 0.03). Patients with SCOs and GCTs had a shorter overall survival when compared to patients with pituitary adenomas (p < 0.01) and a higher rate of thirty-day mortality (3.1% vs 0.0%; p = 0.013). CONCLUSION: SCOs and GCTs are rare pituitary tumors, and their management entails particular challenges. Gross total resection is often not possible, and adjuvant radiation might be employed following subtotal resection.

Surgical Anatomy of the Retrosigmoid Approach With Transtentorial Extension: Protecting the 4th Cranial Nerve.

BACKGROUND AND OBJECTIVES: The retrosigmoid approach with transtentorial extension (RTA) allows us to address posterior cranial fossa pathologies that extend through the tentorium into the supratentorial space. Incision of the tentorium cerebelli is challenging, especially for the risk of injury of the cranial nerve (CN) IV. We describe a tentorial incision technique and relevant anatomic landmarks. METHODS: The RTA was performed stepwise on 5 formalin-fixed (10 sides), latex-injected cadaver heads. The porus trigeminus's midpoint, the lateral border of the suprameatal tubercle (SMT)'s base, and cerebellopontine fissure were assessed as anatomic landmarks for the CN IV tentorial entry point, and relative measurements were collected. A clinical case was presented. RESULTS: The tentorial opening was described in 4 different incisions. The first is curved and starts in the posterior aspect of the tentorium. It has 2 limbs: a medial one directed toward the tentorium's free edge and a lateral one that extends toward the superior petrosal sinus (SPS). The second incision turns inferiorly, medially, and parallel to the SPS down to the SMT. At that level, the second incision turns perpendicular toward the tentorium's free edge and ends 1 cm from it. The third incision proceeds posteriorly, parallel to the free edge. At the cerebellopontine fissure, the incision can turn toward and cut the tentorium-free edge (fourth incision). On average, the CN IV tentorial entry point was 12.7 mm anterior to the SMT base's lateral border and 20.2 mm anterior to the cerebellopontine fissure. It was located approximately in the same coronal plane as the porus trigeminus's midpoint, on average 1.9 mm anterior. CONCLUSION: The SMT and the cerebellopontine fissure are consistently located posterior to the CN IV tentorial entry point. They can be used as surgical landmarks for RTA, reducing the risk of injury to the CN IV.

Correlation of older age with better progression-free survival despite less aggressive resection in nonfunctioning pituitary adenomas.

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.