The Prevalence of the Middle Clinoid Process: A Cross-Sectional Comparative Study in Patients with and without Pathology of the Sella Turcica.

Background The middle clinoid process (MCP), particularly caroticoclinoid ring (CCR) type of the MCP, is an important part of the sphenoid bone for skull base surgery. Previous studies have shown a wide range of MCP prevalence affected by various factors. However, no study has investigated the association between the MCP and the presence of sellar lesions. Objectives The main aim of this study was to evaluate the prevalence of the MCP in the Thai population and factors associated with its presence. Materials and Methods We conducted a cross-sectional study on 400 sides from 200 patients (100 with and 100 without sellar lesions) using cranial computerized tomography scans. Demographic data and MCP characteristics were collected. The association between individual variables and the presence of the MCP was determined by univariate and multivariate analysis. Results The MCP was identified in 168 of 400 sides (42%). Patients with sellar lesions had a significantly lower prevalence of the MCP compared with normal controls (29.5% versus 54.5%, p < 0.001). Of all MCP only 6% were the CCR type. Univariate and multivariate analysis showed that the absence of the sellar lesion was the only factor significantly associated with presence of the MCP (odds ratio: 2.86; 95% confidence interval: 1.90-4.32; p < 0.001). Conclusion The prevalence of the MCP was relatively high in the Thai population, while the prevalence of the CCR was relatively low compared with previous studies. The absence of sellar lesions was the only factor associated with the presence of the MCP.

Full Endoscopic Transcranial Resection of Meningiomas.

OBJECTIVE: Tumors of the skull base can be accessed through different routes. Recent advantages in minimally invasive techniques have shown that very different routes can be applied for optimal tumor resection depending on the technical equipment, the surgeon's preference, and the individual anatomy of the pathology. Here, the authors present their technique for pure endoscopic transcranial tumor resection in meningiomas. METHODS: Out of the cases of the Department of Neurosurgery, Homburg Saar Germany of the last 10 years, all endoscopic procedures for meningiomas were analyzed. Particular attention was given to evaluating the peculiarities of those meningiomas that were treated purely endoscopically. RESULTS: While the endoscope was used in a large number of skull base meningiomas in endonasal approaches or for endoscopic inspection in transcranial skull base surgery, only a small number of meningiomas was selected for a purely endoscopically performed resection. The characteristics of these cases were rather a small lesion, straight access, and a keyhole position of the craniotomy. A complete resection of the tumor was achieved in all cases. Conversion to the microscope was not necessary in any case. There were no technical issues or complications associated with a fully endoscopic resection. DISCUSSION: The endoscope is a valuable tool for visualization in meningioma surgery. In most cases, it is applied for an endonasal route or for endoscopic inspection in transcranial microsurgical cases. However, small to medium-sized meningiomas that can be accessed through the keyhole approach are good candidates for pure endoscopic resection. Because of the very high magnification and the minimally invasive nature of this approach, it should be considered more frequently in suitable lesions.

Transorbital Route to Intracranial Space.

The endoscopic superior eyelid transorbital approach has emerged as a notable and increasingly utilized surgical technique in recent years. This chapter presents an overview of the approach, tracing its historical development and highlighting its growing acceptance within the skull base community.Beginning with an introduction and historical perspective, the chapter outlines the evolution of the transorbital approach, shedding light on its origins and the factors driving its adoption. Subsequently, a comprehensive exploration of the anatomic bone pillars and intracranial spaces accessible via this approach is provided. Hence, five bone pillars of the transorbital approach were identified, namely the lesser sphenoid wing, the anterior clinoid, the sagittal crest, the middle cranial fossa, and the petrous apex. A detailed correlation of those bone targets with respective intracranial areas has been reported.Furthermore, the chapter delves into the practical application of the technique through a case example, offering insights into its clinical utility, indications, and limitations.

Treating Trigeminal Schwannoma through a Transorbital Approach: A Systematic Review.

Background: Trigeminal schwannomas (TSs) are uncommon tumors found along any segment of the fifth cranial nerve (CN V). Typically located at the skull base, these benign tumors carry substantial morbidity due to the extent of traditional surgical methods. Minimally invasive endoscopic surgery such as the endoscopic transorbital approach (ETOA) presents promising new avenues for treatment, with the transorbital approach emerging as a potentially successful alternative. Methods: This review systematically assesses the application of the ETOA in treating TSs. PubMed, Ovid MEDLINE, and Embase were thoroughly searched for articles detailing the use of the ETOA in clinical case studies. The outcomes of interest encompassed epidemiological profiling, surgical results, and complication rates. Results: This study included 70 patients with TSs (from six studies), with 22 males (31.4%) and 58 females (68.6%). Patients averaged 55 years and were monitored for around 16.4 months (on average). In most tumors, the middle cranial fossa was involved to some degree. The majority (87.2%) were large (3-6 cm) and underwent gross total resection (GTR) or near-total resection in 87.2% of patients. Preoperatively, sensory alterations were common, along with proptosis, neuropathic pain, and diplopia. Postoperatively, complications included ptosis, diplopia, sensory impairment, corneal keratopathy, masticatory difficulty, and neuralgia. The pure ETOA was the primary surgical technique used in 90% of cases, with no recurrence observed during the follow-up period. Conclusions: Using the ETOA to treat TSs demonstrated an oncologic control rate of 87.2%. Postoperative complications including ptosis, diplopia, and sensory disturbances have been observed, but careful monitoring and management can mitigate these problems. The ETOA emerges as a viable surgical option, especially for tumors involving the middle cranial fossa, capable of adapting to individual patient needs and demonstrating efficacy in TS management.

Longer-term surveillance imaging and endoscopy critical for majority of patients in detection of sinonasal malignancy recurrence.

BACKGROUND: Sinonasal malignancy surveillance paradigms are often based on Head and Neck National Comprehensive Cancer Network guidelines, which do not recommend standard surveillance imaging beyond 6 months without concerning symptomatology or physical examination findings. METHODS: This was a retrospective analysis of all patients who underwent resection of sinonasal malignancy at a tertiary care center over a 20-year period from 2000 to 2020, with an ensuing surveillance period demonstrating recurrence. RESULTS: Fifty-two patients with sinonasal malignancy recurrence were included, with an average time to recurrence of 30.9 months and a follow-up period of over 60 months. Recurrence was diagnosed by routine imaging or endoscopy in asymptomatic patients in a majority (60%) of cases, while the remaining minority of diagnoses followed new symptomatology. Asymptomatic recurrence was associated with perineural spread of tumor at initial resection (p = 0.025), but not with age (p = 0.85) or stage at diagnosis (p = 0.68). Expectedly, positron emission tomography/computed tomography (CT) more often detected regional or distant recurrence, while structural imaging (CT/magnetic resonance imaging) demonstrated more frequent detection of recurrence in those with perineural spread of tumor (p = 0.01). CONCLUSIONS: Our findings support high rates of asymptomatic recurrence in sinonasal malignancy, with the majority of recurrences diagnosed by routine endoscopy or imaging. Tailored and extended surveillance guidelines are necessary relative to those utilized for other head and neck mucosal cancers, and are especially appropriate when features such as perineural spread are present.

Cochlear implantation in patients with inner ear schwannomas: a systematic review and meta-analysis of audiological outcomes.

PURPOSE: In patients with inner ear schwannomas (IES), reports on hearing rehabilitation with cochlear implants (CI) have increased over the past decade, most of which are case reports or small case series. The aim of this study is to systematically review the reported hearing results with CI in patients with IES considering the different audiologic outcome measures used in different countries. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, a search of published literature was conducted. We included patients with IES (primary or with secondary extension from the internal auditory canal (IAC) to the inner ear, sporadic or NF2 related) undergoing cochlear implantation with or without tumour removal. The audiological results were divided into the categories "monosyllables", "disyllables", "multisyllabic words or numbers", and "sentences". RESULTS: Predefined audiological outcome measures were available from 110 patients and 111 ears in 27 reports. The mean recognition scores for monosyllabic words with CI were 55% (SD: 24), for bisyllabic words 61% (SD: 36), for multisyllabic words and numbers 87% (SD: 25), and 71% (SD: 30) for sentences. Results from for multisyllabic words and numbers in general showed a tendency towards a ceiling effect. Possible risk factors for performance below average were higher complexity tumours (inner ear plus IAC/CPA), NF2, CI without tumour removal ("CI through tumour"), and sequential cochlear implantation after tumour removal (staged surgery). CONCLUSION: Hearing loss in patients with inner ear schwannomas can be successfully rehabilitated with CI with above average speech performance in most cases. Cochlear implantation thus represents a valuable option for hearing rehabilitation also in patients with IES while at the same time maintaining the possibility of MRI follow-up. Further studies should investigate possible risk factors for poor performance. Audiological tests and outcome parameters should be reported in detail and ideally be harmonized to allow better comparison between languages.

American Rhinologic Society expert practice statement part 2: Postoperative precautions and management principles following endoscopic skull base surgery.

The goal of this American Rhinologic Society expert practice statement (EPS) is to summarize the best available evidence regarding postoperative precautions for patients following endoscopic skull base surgery for intradural pathology. These topics include the administration of postoperative nasal hygiene; patient mobilization and activity level; the resumption of continuous positive airway pressure in patients with obstructive sleep apnea; and the timing and capacity with which a patient may be subjected to barotrauma, such as air travel postoperatively. This EPS was developed following the recommended methodology and approval process as previously outlined. Given the diverse practices and limited agreement on the accepted principles regarding postoperative precautions for patients following skull base surgery, this EPS seeks to summarize the existing literature and provide clinically relevant guidance to bring clarity to these differing practice patterns. Following a modified Delphi approach, four statements were developed, all of which reached consensus. Because of the paucity of literature on these topics, these statements represent a summation of the limited literature and the experts' opinions. These statements and the accompanying evidence are summarized below, along with an assessment of future needs.

Melanoma of the external auditory canal: case report and systematic literature review.

Melanoma of the external auditory canal (EAC) is particularly rare and poorly understood, with limited available data on management and survival. This systematic review aims to analyze existing data and provide insights into the management and prognosis the beginning of EAC melanoma. It is conducted using Pubmed and Scopus databases from the beginning to July 2023 and it follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines. Searches are performed using the search string "(melanoma) AND (external auditory canal)".The review includes a total of 30 patients diagnosed with EAC melanoma, supplemented by an additional case from the authors' clinical experience. The role of Breslow thickness as a determining factor for the choice of surgery remains inconclusive due to limited available data. Sentinel lymph node biopsy and adjuvant therapy are sparingly employed, indicating the need for standardized guidelines. Patients in the study demonstrate a 50% overall survival rate at 5 years.EAC Melanoma is a rare and aggressive malignancy with limited therapeutic guidelines. Surgical interventions, including wide local excision and lateral temporal bone resection, are the primary treatment options for patients without distant metastases.

Work-Related Musculoskeletal Disorders in Endoscopic Sinus and Skull Base Surgery: A Systematic Review With Meta-analysis.

OBJECTIVE: Endoscopic sinus and skull base surgery has led to significant improvements in patient outcomes, yet may have come at a cost to surgeons' musculoskeletal (MSK) health. We aimed to determine the prevalence and characteristics of work-related MSK disorders (WRMDs) in endoscopic sinus and skull base surgeons; to investigate contributing factors for WRMD in this population; and to evaluate the effectiveness of ergonomic interventions on the severity or prevalence of WRMD in this population. DATA SOURCES: Medline, Embase, CINAHL, Web of Science, and Scopus from inception to April 2, 2024. A bibliographic examination was performed for further papers. REVIEW METHODS: Inclusion criteria included original peer-reviewed papers with work-related MSK outcomes (prevalence, contributing factors, and interventions) relating to endoscopic sinus and/or skull base surgeons in any language. RESULTS: Of 25,772 unique citations, 37 studies met the inclusion criteria. The pooled lifetime, point, and 12-month prevalences of WRMD were 75.9% (95% confidence interval; I2, 67.2%-83.6%, I2 95.6%), 80.8% (77.0%-84.3%, I2 98.0%), and 82.0% (71.8%-90.3%, I2 60.96%) respectively. The neck, lumbar spine, and thoracic spine were the most commonly involved areas. One of 9 studies on contributing factors investigated discomfort as an outcome. The remainder focussed on surrogate outcomes (eg, posture, hand dysfunction). Two of the 13 intervention studies investigated pain or fatigue as an outcome. The remainder targeted posture, muscle activity, or workload. CONCLUSION: WRMDs are highly prevalent in endoscopic sinus and skull base surgeons. Further studies focusing on the direct outcomes of WRMD such as pain are needed.

Multiportal Retrograde Endoscopy to Enhance Surgical Target Visualization: A Pilot Study.

Objective Current transnasal endoscopic techniques for sinus and skull base surgery use a single endoscope to provide visualization from one perspective curtailing depth perception and compromising visualization of the instrument-target interface. The view can be blocked by instruments, and collisions between instruments often occur. The objective of this study was to investigate the use of multiportal retrograde endoscopy to provide more accurate manipulation of the surgical target. Design Maxillary antrostomy and frontal sinusotomy were performed on three different cadavers by three different surgeons. A zero-degree rigid endoscope was introduced through the nose for the standard transnasal approach. A flexible endoscope was introduced transorally, directed past the palate superiorly, and then flexed 180 degrees for the retrograde view. Videos of the standard transnasal view from the rigid endoscope and retrograde view from the flexible endoscope were recorded simultaneously. Results All surgeries were able to be performed with dual-screen viewing of the standard and retrograde view. The surgeons noted that they utilized the retrograde view to adjust the location of ends/tips of their instruments. Four surgeons reviewed the videos and individually agreed that the visualization achieved provided a perspective otherwise not attainable with rigid transnasal endoscopy alone. Conclusion High-quality visualization of surgical targets such as the frontal or maxillary ostia can be challenging with rigid endoscopes alone. Multiportal retrograde endoscopy provides proof of concept that additional views of a surgical target can be achieved. Additional work is needed to further develop indications, techniques, and generalizability to targets beyond those investigated here.

Long-term outcomes in advanced anterior skull base malignancy: a single quaternary institution experience.

BACKGROUND: Advanced skull base malignancies are a heterogenous subset of head and neck cancers, and management is often complex. In recent times, there has been a paradigm shift in surgical technique and the advent of novel systemic options. Our goal was to analyse the long-term outcomes of a single quaternary head and neck and skull base service. METHODS: A retrospective review of 127 patients with advanced anterior skull base malignancies that were treated at our institution between 1999 and 2015 was performed. Multiple variables were investigated to assess their significance on 5 and 10-year outcomes. RESULTS: The mean age was 60.9 (± 12.6 SD). Sixty-four percent were males and 36% were females. Ninety percent of patients had T4 disease. Median survival time was 133 months. The 5-year overall survival (OS) was 66.2%, disease-specific survival (DSS) was 74.7%, and recurrence-free survival (RFS) was 65.0%. The 10-year OS was 55.1%, DSS was 72.1%, and RFS was 53.4%. Histological type and margin status significantly affected OS & DSS. CONCLUSION: Surgical management of advanced skull base tumours has evolved over the last few decades at our institution with acceptable survival outcomes and complication rates. Histological diagnosis and margin status are the main predictors of survival. The addition of neoadjuvant systemic agents in current trials may improve outcomes.

Three montages for Transcranial electric stimulation in predicting the early post-surgery outcome of the facial nerve functioning.

OBJECTIVE: We assessed the Transcranial Electrical Stimulation (TES)-induced Corticobulbar-Motor Evoked Potentials (Cb-MEPs) evoked from Orbicularis Oculi (Oc) and Orbicularis Oris (Or) muscles with FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6/-Cz stimulation, during IntraOperative NeuroMonitoring (IONM) in 30 patients who underwent skull-base surgery. METHODS: before (T0) and after (T1) the surgery, we compared the peak-to-peak amplitudes of Cb-MEPs obtained from TES with C3/C4-Cz, C5/C6-Cz and FCC5h/FCC6h-Mz. Then, we compared the response category (present, absent and peripheral) related to different montages. Finally, we classified the Cb-MEPs data from each patient for concordance with clinical outcome and we assessed the diagnostic measures for Cb-MEPs data obtained from FCC5h/FCC6h-Mz, C3/C4-Cz and C5/C6-Cz TES stimulation. RESULTS: Both at T0 and T1, FCC5h/FCC6h-Mz stimulation evoked larger Cb-MEPs than C3/C4-Cz, less peripheral responses from direct activation of facial nerve than C5/C6-Cz. FCC5h/FCC6h-Mz stimulation showed the best accuracy and specificity of Cb-MEPs for clinical outcomes. CONCLUSIONS: FCC5h/FCC6h-Mz stimulation showed the best performances for monitoring the facial nerve functioning, maintaining excellent diagnostic measures even at low stimulus voltages. SIGNIFICANCE: We demonstrated that FCC5h/FCC6h-Mz TES montage for Cb-MEPs in IONM has good accuracy in predicting the post-surgery outcome of facial nerve functioning.

[Overview and prospects of endoscopic skull base surgery].

Endoscopic skull base surgery presents significant technical challenges and high surgical risks, requiring collaboration among multiple disciplines such as otolaryngology, neurosurgery, ophthalmology, and oral maxillofacial surgery. In recent years, there has been rapid development in endoscopic skull base surgery, characterized by flourishing anatomical research and an expanding range of surgical indications. The future brings both opportunities and challenges, and endoscopic skull base surgery must grasp new directions in medical development, actively providing patients with safer and more effective treatment options.

Peri-operative management of endoscopic endonasal cerebrospinal fluid leak repair: an international survey.

PURPOSE: Peri-operative management of nasal cerebrospinal fluid (CSF) leaks is not consensual due to limited evidence. The main aim of this study was to identify key factors in peri-operative management of endoscopic endonasal CSF leak repair among international experts. METHODS: A 60-item survey questionnaire collected opinions of members of international learned societies of ENT surgeons and neurosurgeons on nasal packing, post-operative instructions, antibiotic prophylaxis, and CSF volume depletion. RESULTS: The survey had 153 respondents (124 otorhinolaryngologists and 29 neurosurgeons). A resting position was recommended by 85% (130/151) of respondents for extended CSF leak of the anterior skull base, mainly in Fowler's position (72% (110/153)). Nasal packing was used by 85% (130/153) of respondents; 33.3% (51/153) used it to stabilize the reconstruction, and 22.2% (34/153) to prevent bleeding. It was usually removed after 48 h in 44.4% of cases (68/153). CSF depletion was considered by 47.1% (72/153) of respondents in case of CSF leak recurrence and by 34.6% (53/153) in cases of increased intracranial pressure. All respondents gave specific postoperative instructions to patients including driving, running, swimming, diving restrictions and flighting restrictions. In subgroup analysis, ENT surgeons more often recommended a resting position than neurosurgeons (71% vs. 37.9% ; p = 0.0008) and prescribed more antibiotics (82.3% vs. 21.4% ; p < 0.0001). CONCLUSION: Although postoperative management after CSF closure remains challenging and not codified, this international survey revealed some points of consensus concerning resting position and restriction of post-operative activities. Prospective clinical studies must be undertaken to evaluate their efficiency.

Effect of endoscopic endonasal skull base approaches on olfactory function and facial development in children.

INTRODUCTION: Endoscopic approaches for skull base pathologies are increasingly being performed, and the subsequent complications, especially in the long term, have also been partially clarified. However, there is no information on the effects of endoscopic endonasal skull base surgeries (EESBS) in children on odor and facial development in parallel with long-term development. We conducted this study to investigate postoperative olfactory function and facial development in pediatric patients who underwent skull base surgery using the endoscopic endonasal method. METHODS: We evaluated the smell test, sinonasal symptoms, and facial development of pediatric patients who underwent endoscopic endonasal skull base surgery after long-term follow-up. Odor was evaluated using the "Sniffin' Sticks" test kit, which assessed the T (odor threshold), D (odor discrimination), and I (odor identification) parameters. Sinonasal symptoms were evaluated using the SNOT-22 (sinus-nose outcome test) questionnaire. SNA (sella-nasion-A point), SNB (sella-nasion-B point), and ANB (A point-nasion-B point) angles were calculated from maxillofacial tomography and magnetic resonance imaging) to evaluate facial development. Data were compared with those of the healthy control group. RESULTS: We included 30 patients comprising 19 (63.3%) boys and 11 (36.7%) girls, with no age difference between case and control groups. The mean follow-up period was 7 years. Odor test data, cephalometric measurements, and SNOT-22 analysis results showed no statistically significant differences between the two groups. CONCLUSION: To our knowledge, this is a comprehensive study with the longest follow-up period in terms of evaluation of facial development after EESBS in children to analyze odor using the Sniffin' Sticks test kit and the quality of life using SNOT-22. Olfactory function, facial development, and quality of life remained unaffected after long-term follow-up after EESBS  in children. Although this surgical approach is minimally invasive, we recommend considering the possibility of complications, and the procedure should be performed by an experienced surgical team with adequate equipment.

Jugular bulb anatomical variations and pneumatization patterns: a comprehensive CBCT analysis.

PURPOSE: This study aims to assess the anatomical possibilities of the jugular bulb (JB). METHODS: Fifty archived CBCT scans were analyzed. RESULTS: The average distance between the internal acoustic canal (IAC) and the JB was 7.97 mm on both sides (Right: SD = 2.56 mm, range 3.16-13.3 mm; Left: SD = 2.5 mm, range 2.9-13.6 mm). JB walls' pneumatization was classified into eight patterns. Deep petrosal cells (DPCs) prevailed in the lateral wall of the JB. The absence of pneumatization (NP) was commonly found on the left side. The presence of infralabyrinthine and hypotympanic cells varied. Less common types included accessory occipital cells (AOCs), posteromedial tracts (PMTs), and basi-occipital cells (BOCs), which determined a consistent variation of the lateral wall pneumatization patterns. Pneumatization of the medial wall was not observed in 50 right sides and 49 left sides. The inferior wall analysis revealed symmetry in AOC distribution and a predominant occurrence of NP. Cases with hypotympanum (HT) in the lateral wall showed a statistically significant IAC-JB distance increase by an average of 4.67 mm compared to NPs. Specific pneumatizations, particularly HT on the lateral side, have a significant effect on the IAC-JB distance, showing a clear pattern of increasing distance from DPC to NP and then to HT. A significant distance increase in HT pneumatization was noted. There were also recorded instances of JB hypoplasia and hyperplasia, JB diverticula, dehiscent JBs, and high JBs. CONCLUSION: This study establishes a novel classification of JB pneumatizations to aid in the understanding of the temporal bone anatomy.

Single-Center Experience in Microsurgical Resection of Acoustic Neurinomas and the Benefit of Microscope-Based Augmented Reality.

Background and Objectives: Microsurgical resection with intraoperative neuromonitoring is the gold standard for acoustic neurinomas (ANs) which are classified as T3 or T4 tumors according to the Hannover Classification. Microscope-based augmented reality (AR) can be beneficial in cerebellopontine angle and lateral skull base surgery, since these are small areas packed with anatomical structures and the use of this technology enables automatic 3D building of a model without the need for a surgeon to mentally perform this task of transferring 2D images seen on the microscope into imaginary 3D images, which then reduces the possibility of error and provides better orientation in the operative field. Materials and Methods: All patients who underwent surgery for resection of ANs in our department were included in this study. Clinical outcomes in terms of postoperative neurological deficits and complications were evaluated, as well as neuroradiological outcomes for tumor remnants and recurrence. Results: A total of 43 consecutive patients (25 female, median age 60.5 ± 16 years) who underwent resection of ANs via retrosigmoid osteoclastic craniotomy with the use of intraoperative neuromonitoring (22 right-sided, 14 giant tumors, 10 cystic, 7 with hydrocephalus) by a single surgeon were included in this study, with a median follow up of 41.2 ± 32.2 months. A total of 18 patients underwent subtotal resection, 1 patient partial resection and 24 patients gross total resection. A total of 27 patients underwent resection in sitting position and the rest in semi-sitting position. Out of 37 patients who had no facial nerve deficit prior to surgery, 19 patients were intact following surgery, 7 patients had House Brackmann (HB) Grade II paresis, 3 patients HB III, 7 patients HB IV and 1 patient HB V. Wound healing deficit with cerebrospinal fluid (CSF) leak occurred in 8 patients (18.6%). Operative time was 317.3 ± 99 min. One patient which had recurrence and one further patient with partial resection underwent radiotherapy following surgery. A total of 16 patients (37.2%) underwent resection using fiducial-based navigation and microscope-based AR, all in sitting position. Segmented objects of interest in AR were the sigmoid and transverse sinus, tumor outline, cranial nerves (CN) VII, VIII and V, petrous vein, cochlea and semicircular canals and brain stem. Operative time and clinical outcome did not differ between the AR and the non-AR group. However, use of AR improved orientation in the operative field for craniotomy planning and microsurgical resection by identification of important neurovascular structures. Conclusions: The single-center experience of resection of ANs showed a high rate of gross total (GTR) and subtotal resection (STR) with low recurrence. Use of AR improves intraoperative orientation and facilitates craniotomy planning and AN resection through early improved identification of important anatomical relations to structures of the inner auditory canal, venous sinuses, petrous vein, brain stem and the course of cranial nerves.

Diabetes Insipidus after Endoscopic Endonasal Pituitary Macroadenoma Resection: Correlation of Patient and Surgery-Related Risk Factors.

Purpose This article aims to identify patient- and surgery-related factors that could predict the development of postoperative central diabetes insipidus (DI). Methods This is a retrospective case-control study conducted at a single-institution tertiary referral center. Patients undergoing endoscopic endonasal skull base surgery for pituitary adenoma between November 2018 and April 2023 were recruited. The main outcome measures collected include age, gender, comorbidities, tumor type, postoperative DI, intraoperative and postoperative cerebrospinal fluid (CSF) leak, flow of CSF leak, number of layers required for repair, the use of nasal packing, and hospital length of stay. Results A total of 20 patients developed DI postoperatively. Patients' demographic and comorbidity profile did not correlate with DI development. The encounter of an intraoperative CSF leak was correlated with postop DI (chi-square (1) = 18.35, p < 0.001) with a relative risk (RR) of 2.7 (confidence interval [CI] = 1.37-5.28). The use of nasal packs was also correlated with postop DI (chi-square (1) = 10.17, p = 0.001) with a RR of 1.8 (CI = 1.15-2.87). Defects requiring a two or more layers for reconstruction also correlated with postop DI compared to single layer repairs (chi-square (1) = 12.15, p < 0.001) irrelevant of the materials used. Development of DI postop correlated with an increased hospital length of stay ( t (64) = -3.35, p = 0.001). Conclusion The physician should be careful when evaluating patients with pituitary adenomas in the postoperative period, particularly those with intraoperative CSF leak, nasal packing, and those who underwent multilayer reconstruction of the surgical defect.

Surgical treatment of cystic pituitary adenomas: literature-based definitions and postoperative outcomes.

BACKGROUND AND OBJECTIVES: To survey the applied definitions of 'cystic' among pituitary adenomas and evaluate whether postoperative outcomes differ relative to non-cystic counterparts. METHODS: A literature search and meta-analysis was performed using PRISMA guidelines. Studies were eligible if novel data were reported regarding the applied definition of 'cystic' and postoperative outcomes among cases of surgically treated pituitary adenomas. Data were pooled with random effects meta-analysis models into cohorts based on the applied definition of 'cystic'. Categorical meta-regressions were used to investigate differences between cohorts. Among studies comparing cystic and non-cystic pituitary adenomas, meta-analysis models were applied to determine the Odds Ratio [95% Confidence Interval]. Statistical analyses were performed using Comprehensive Meta-Analysis (CMA, 4.0), with a priori significance defined as P < 0.05. RESULTS: Ten studies were eligible yielding 283 patients with cystic pituitary adenomas. The definitions of 'cystic' mainly varied between the visual appearance of cystic components on preoperative magnetic resonance imaging and a volumetric definition requiring 50% or greater of tumor volume exhibiting cystic components. Tumor diameter was seldom reported with an associated standard deviation/error, limiting meta-analyses. When the data were pooled in accordance with the definition applied, there were no significant differences in the rates of gross total resection (P = 0.830), endocrinologic remission (P = 0.563), and tumor recurrence (P = 0.320). Meta-analyses on studies comparing cystic versus non-cystic pituitary adenomas indicated no significant difference in the rates of gross total resection (P = 0.729), endocrinologic remission (P = 0.857), and tumor recurrence (P = 0.465). CONCLUSION: Despite some individual studies describing a significant influence of pituitary adenoma texture on postoperative outcomes, meta-analyses revealed no such differences between cystic and non-cystic pituitary adenomas. This discrepancy may be explained in part by the inconsistent definition of 'cystic' and between-group differences in tumor size. A notion of a field-standard definition of 'cystic' among pituitary adenomas should be established to facilitate inter-study comparisons.

A primary sphenoclival skull base neuroendocrin tumor: A rare case report and literature review.

INTRODUCTION AND IMPORTANCE: Primary intracranial neuroendocrine tumors (NETs) are exceedingly rare, often posing diagnostic challenges, particularly in non-secreting variants. These tumors may initially present with nonspecific symptoms, leading to delayed diagnosis and potential neurological complications. CASE REPORT: We present the case of a 33-year-old male admitted with a one-year history of progressively worsening headache accompanied by acute left ptosis and diplopia. Initial examination revealed left eye ptosis and hypotropia, indicative of third and fourth cranial nerve paralysis. Cavoscopy revealed a mild anterior wall bulge of the sphenoid with normal mucosa. MRI imaging unveiled an expansive clival process extending towards the sellar region and left cavernous sinus, completely occupying the sphenoid sinus and exerting mass effect on the pituitary stalk. Hormonal assays were within reference ranges, ruling out a hormonally-active tumor. Endoscopic endonasal surgery for biopsy revealed a low-grade neuroendocrine tumor positive for cytokeratin AE1/AE2, chromogranin A, synaptophysin, and beta-catenin, with a Ki-67-labeling index <2 %. Somatostatin receptor scintigraphy confirmed intense hyper fixation of the tracer in the sphenoidal tumor, supporting its neuroendocrine origin. The patient declined surgical intervention after informed consent, opting for C1 somatostatin analogs prior to radiotherapy. One-year follow-up demonstrated symptom stability with no tumor progression. CLINICAL DISCUSSION: To this day, no consensus among reports concerning the optimal management of these cases. Imaging assessment is crucial to validate the primary nature of the tumor and to exclude any distant localization. Various therapeutic modalities, such as surgery, radiotherapy, and somatostatin analogs, should be considered based on the specific characteristics and extent of the tumor. CONCLUSION: Our case is a clear reminder that neuroendocrine tumors should be considered as a differential diagnosis for skull base neoplasms.