Changes in pituitary adenoma patient presentation and outcomes during the COVID pandemic at a Pituitary Center of Excellence.

PURPOSE: The COVID-19 pandemic caused significant disruption to the surgical care of patients. The aim of this study was to analyze the impact of the pandemic on endoscopic endonasal surgery (EES) for patients with a pituitary adenoma. METHODS: Patients from 2015 to 2022 that had EES for a pituitary adenoma were included in this study. Patients were separated into pre-COVID (January 2015-March 2020) and COVID (March 2020-September 2022) groups. Univariate analysis was done using chi-square, fisher exact tests, and t-tests to compare groups. RESULTS: This study included 492 patients that had EES for their pituitary adenoma. There were 314 patients in the pre-COVID group and 178 patients in the COVID group. Patients in the COVID group had a higher risk analysis index (RAI) frailty score (15 ± 10 pre-COVID vs. 20 ± 9 COVID, P < 0.001) and a higher American Society of Anesthesiology (ASA) physical status score (3 or 4) (72.0% pre-COVID vs. 81.9% COVID, P = 0.02). There were significantly more macroadenoma cases (87.6% pre-COVID vs. 94.4% COVID, P = 0.02) and extrasellar surgical approaches (45.2% pre-COVID vs. 61.2% COVID, P < 0.001) during COVID. There was no significant difference in length of stay (LOS) and readmission rates between groups. CONCLUSIONS: Patients that presented during the pandemic tended to be more frail, have more comorbidities, and require additional extrasellar surgical approaches. Despite changes in clinical presentation and operative management, the LOS and readmission rate remained stable during COVID, supporting the safety of this procedure during the recent pandemic.

The utility of inflammatory biomarkers in predicting overall survival and recurrence in skull base chordoma.

OBJECTIVE: Numerous studies have investigated the impact of inflammatory factors in cancer, yet few attempts have been made to investigate these markers in skull base chordoma (SBC). Inflammatory values including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), systemic immune inflammation index (SII), and systemic inflammation response index (SIRI) can serve as prognostic markers in various cancers. This study aimed to determine whether these inflammatory factors influence overall survival (OS) or progression-free survival (PFS) in patients with primary SBC. METHODS: The electronic medical records of patients with primary SBC who underwent resection from 2001 to 2020 were retrospectively reviewed for the associations of sex, age at diagnosis, preoperative steroid use, tumor volume, extent of resection, adjuvant radiation after surgery, tumor metastasis, Ki-67 index, percent homozygous deletion of 9p23 and percent 1p36 loss, and potential prognostic inflammatory markers of NLR, PLR, LMR, SII, and SIRI with the primary outcome measures of OS and PFS. Maximum log-rank statistical tests were used to determine inflammatory marker thresholds for grouping prior to Kaplan-Meier and Cox proportional hazards analysis for OS and PFS of the elucidated groups. RESULTS: The cohort included 115 primary SBC patients. The mean ± SD tumor volume was 23.0 ± 28.0 cm3, 73% of patients received gross-total resection, 40% received postoperative radiation, 25% had local recurrence, and 6% had subsequent metastatic disease (mean follow-up 47.2 months). Univariable Cox analysis revealed that NLR (p < 0.01), PLR (p = 0.04), LMR (p = 0.04), SII (p < 0.01), and SIRI (p < 0.01) were independently associated with PFS. Additionally, NLR (p = 0.05) and SII (p = 0.03) were significant in multivariable Cox analysis of PFS. However, both univariable and multivariable Cox analysis revealed no correlations with OS. CONCLUSIONS: The routine assessment of inflammatory biomarkers such as NLR and SIRI could have prognostic value in postresection SBC patients.

Anterolateral keyhole transorbital routes to the skull base: a comparative anatomical study.

OBJECTIVE: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb). METHODS: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined. RESULTS: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb. CONCLUSIONS: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

The NIH pediatric/young adult chordoma clinic and natural history study: Making advances in a very rare tumor.

BACKGROUND: Chordomas are rare tumors arising from the skull base and spine, with approximately 20 pediatric chordoma cases in the Unitedn States per year. The natural history and optimal treatment of pediatric chordomas, especially poorly differentiated and dedifferentiated subtypes, is incompletely understood. Herein, we present findings from our first National Cancer Institute (NCI) chordoma clinic and a retrospective analysis of published cases of pediatric poorly differentiated chordomas (PDC) and dedifferentiated chordomas (DC). METHODS: Patients less than 40 years old with chordoma were enrolled on the NCI Natural History and Biospecimens Acquisitions Study for Children and Adults with Rare Solid Tumors protocol (NCT03739827). Chordoma experts reviewed patient records, evaluated patients, and provided treatment recommendations. Patient-reported outcomes, biospecimens, and volumetric tumor analyses were collected. A literature review for pediatric PDC and DC was conducted. RESULTS: Twelve patients (median age: 14 years) attended the clinic, including four patients with active disease and three patients with PDC responsive to systemic therapy. Consensus treatment, management, and recommendations were provided to patients. Literature review returned 45 pediatric cases of PDC or DC with variable treatments and outcomes. CONCLUSIONS: A multidisciplinary expert clinic was feasible and successful in improving understanding of pediatric chordoma. While multimodal approaches have all been employed, treatment for PDC has been inconsistent and a recommended standardized treatment approach has not been defined. Centralized efforts, inclusive of specialized chordoma-focused clinics, natural history studies, and prospective analyses will help in the standardization of care for this challenging disease.

Postsurgical outcomes of nonfunctioning pituitary adenomas: a patient-level meta-analysis.

BACKGROUND: Surgical resection is the main treatment for symptomatic nonfunctioning pituitary adenomas (NFPA). We aimed to analyze the impact of surgical approach, completeness of resection, and postoperative radiotherapy on long-term progression-free survival (PFS) of NFPA, using individual patient data (IPD) meta-analysis. METHODS: An electronic literature searched was conducted on PubMed, EMBASE, and Web of Science from database inception to 6 November 2022. Studies describing the natural history of surgically resected NFPA, with provision of Kaplan-Meier curves, were included. These were digitized to obtain IPD, which was pooled in one-stage and two-stage meta-analysis to determine hazard ratios (HRs) and 95%CIs of gross total resection (GTR) versus subtotal resection (STR), and postoperative radiotherapy versus none. An indirect analysis of single-arm data between endoscopic endonasal (EES) and microscopic transsphenoidal (MTS) surgical technique was also performed. RESULTS: Altogether, eleven studies (3941 patients) were retrieved. PFS was significantly lower in STR than GTR (shared-frailty HR 0.32, 95%CI 0.27-0.39, p < 0.001). Postoperative radiotherapy significantly improved PFS compared to no radiotherapy (shared-frailty HR 0.20, 95%CI 0.15-0.26, p < 0.001), including in the subgroup of patients with STR (shared-frailty HR 0.12, 95%CI 0.08-0.18, p < 0.001). Similar PFS was observed between EES and MTS (indirect HR 1.09, 95%CI 0.92-1.30, p = 0.301). CONCLUSIONS: This systematic review and patient-level meta-analysis provides a robust prognostication of surgically treated NFPA. We reinforce current guidelines stating that GTR should be the standard of surgical resection. Postoperative radiotherapy is of considerable benefit, especially for patients with STR. Surgical approach does not significantly affect long-term prognosis. REGISTRATION: PROSPERO CRD42022374034.

The role of endoscopic endonasal surgery in the management of prolactinomas based on their invasiveness into the cavernous sinus.

PURPOSE: To review our institutional experience with the surgical management of prolactinomas through the endoscopic endonasal approach with specific focus on cavernous sinus invasion. METHODS: Clinical and radiographic data were collected retrospectively from the electronic medical record of 78 consecutive patients with prolactinomas undergoing endoscopic endonasal resection from 2002 to 2019. Immediate and late post-operative remission were defined as prolactin < 20 ng/mL within 14 days and 1-year of surgery without adjuvant therapy, respectively. Cavernous sinus invasion was quantified by Knosp score. RESULTS: A total of 78 patients with prolactinoma, 59% being male, underwent surgical resection with a mean age of 37 ± 13 years. Indications for surgery were medication resistance in 38 patients (48.7%), medication intolerance in 11 (14.1%), and patient preference in 29 (37.2%). Patients with Knosp 0-2 achieved higher immediate remission rates (83.8%) compared to patients with Knosp 3 (58.8%) and Knosp 4 (41.7%) patients (p = 0.003). Long-term remission rates were 48.7% and increased to 71.8% when combined with adjuvant treatments. Knosp 4 prolactinomas had significantly higher tumor volumes, higher preoperative prolactin levels, higher recurrence rates, higher rates of adjuvant therapy utilization, and were more likely to have failed dopamine agonist therapy compared to other tumor grades (p < 0.05). We encountered 18 complications in our series, and no cerebrospinal fluid leaks. CONCLUSION: The endoscopic endonasal approach is a safe and effective modality that can be employed in properly selected patients with invasive prolactinomas. It is associated with improved control and remission rates despite cavernous sinus invasion, though at a lower rate than without invasion.

Cervical paraspinal skeletal muscle index outperforms frailty indices to predict postoperative adverse events in operable head and neck cancer with microvascular reconstruction.

OBJECTIVE: Sarcopenia is increasingly being recognized as a negative prognostic factor in patients with head and neck cancer (HNC). We associate a sarcopenia biomarker measured radiographically from computed tomography (CT) of the neck to postoperative adverse events in patients with operable HNC. PATIENTS AND METHODS: A prospective cohort of treatment-naïve HNC patients undergoing surgery with microvascular reconstruction was performed. Cervical paraspinal skeletal muscle index (CPSMI) was calculated using preoperative CT neck imaging and adjusted for height and sex. Postoperative adverse events, including Clavien-Dindo Grade 3+ complications and fistula, were recorded within 30-days of the index surgery. Multivariate logistic regression was used to evaluate the association between CPSMI and postoperative complications. The modified frailty index (mFI) and Risk Assessment Index (RAI) were compared with CPSMI outcomes. RESULTS: A total of 127 patients with mucosal HNC were included in the study. The mean age was 60.5 years, and 87 (68.5%) patients were male. Sixty Clavien-Dindo grade 3+ events occurred; 17 patients developed an oro/pharyngocutaneous fistula. Low CPSMI was independently associated with Clavien-Dindo Grade 3+ events (OR 2.80, 95% CI of 1.18-6.99) and fistula (OR of 6.10, 95% CI of 1.53-24.3) when adjusted for multiple factors. CPSMI outperformed the mFI and RAI frailty indices to predict postoperative adverse events (p < .05). CONCLUSION: Low CPSMI is independently associated with postoperative adverse events and outperforms current frailty indices inoperable HNC with microvascular reconstruction.

Applications of Endoscopic Endonasal Surgery in Early Childhood: A Case Series.

INTRODUCTION: Endoscopic endonasal surgery (EES) has been slower to gain popularity in early childhood due to anatomical challenges. We sought to describe the safety and efficacy of EES in early childhood. METHODS: All patients younger than 7 years who underwent EES at a large Cranial Base Center from 2002 to 2019 were reviewed as a retrospective cohort study. RESULTS: Thirty-six patients underwent EES before the age of 7 years. Four patients had two-stage EES. Two patients required combined transcranial and endonasal approaches. The mean age at the time of initial surgery was 4 years (range: 1-6). Twenty patients were male, and 16 were female. Of 21 tumors intended for resection, 11 patients had gross total resections, and 10 had near total (>95% tumor removed) resections. Nine patients (43%) had recurrences, of which 6 were craniopharyngiomas (p = 0.01). There was no difference in recurrence rates based on the degree of resection (p = 0.67). Three cerebrospinal fluid (CSF) leaks occurred following primary EES (8%). Following an increase in nasoseptal flap usage (31-52%) and CSF diversion (15-39%) in 2008, there was only one CSF leak out of 23 patients (4 vs. 15%; p = 0.54). Postoperatively, 1 patient developed a permanent new cranial neuropathy, and 1 patient developed a permanent visual field cut. Six patients developed permanent postoperative panhypopituitarism, of which all were craniopharyngiomas (p < 0.001). The mean follow-up was 64 months. CONCLUSIONS: Early childhood EES is both safe and technically feasible for a variety of pathologies.

Reconstruction after endoscopic surgery for skull base malignancies.

INTRODUCTION: The ability to resect malignancies of the ventral skull base using endoscopic endonasal approaches has created a need for effective endoscopic reconstructive techniques. The purpose of this review is to summarize current techniques for reconstruction of large skull base defects during endoscopic endonasal surgery. METHODS: Recent medical literature was reviewed to identify techniques and best practices for repair of skull base defects during endoscopic endonasal surgery. Preference was given to evidence-based recommendations. RESULTS: Superior results are observed with multilayer inlay/onlay grafts supplemented with vascularized flaps. The nasoseptal flap is the primary reconstructive flap for most defects; secondary choices include the lateral nasal wall flap and extracranial pericranial flap. Clival defects are particularly challenging and are further augmented with adipose tissue to prevent pontine herniation. Perioperative management including the use of lumbar cerebrospinal fluid drainage minimizes the risk of a postoperative leak in high-risk patients. Postoperative cerebrospinal fluid leaks are managed similarly to primary leaks and may require use of a secondary vascularized flap. Complications of reconstructive flaps include flap necrosis and cosmetic nasal deformity. CONCLUSION: Large defects of the anterior, middle, and posterior cranial fossae can be managed similarly by adhering to basic principles of reconstruction. Future developments will improve stratification of patients into reconstructive groups and allow tailored reconstructive algorithms. New biomaterials may replace autologous tissue and facilitate endoscopic repair. Improved monitoring will allow for assessment of the reconstructive site with early detection and repair of postoperative cerebrospinal fluid leaks.

Extensive tumor calcification in response to pre-operative reductive chemotherapy in pediatric esthesioneuroblastoma: a case report.

Esthesioneuroblastomas are uncommon tumors in pediatric patients and are typically treated with multimodal therapy. Changes in gross tumor quality and character in response to adjuvant treatment have not been clearly reported. We report the case of a 15-year-old female with a diagnosis of Kadish stage C esthesioneuroblastoma who was treated with neoadjuvant chemotherapy and surgical resection. The patient's tumor demonstrated cytoreduction after chemotherapy but also was found to have calcified. A combined trans-frontal sinus craniotomy with endoscopic endonasal resection was performed and resulted in negative margins and good clinical outcome.

Early practices in endonasal skull base surgery during the COVID-19 pandemic: a global survey.

OBJECTIVE: During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, endoscopic endonasal surgery (EES) is feared to be a high-risk procedure for the transmission of coronavirus disease 2019 (COVID-19). Nonetheless, data are lacking regarding the management of EES during the pandemic. The object of this study was to understand current worldwide practices pertaining to EES for skull base/pituitary tumors during the SARS-CoV-2 pandemic and provide a basis for the formulation of guidelines. METHODS: The authors conducted a web-based survey of skull base surgeons worldwide. Different practices by geographic region and COVID-19 prevalence were analyzed. RESULTS: One hundred thirty-five unique responses were collected. Regarding the use of personal protective equipment (PPE), North America reported using more powered air-purifying respirators (PAPRs), and Asia and Europe reported using more standard precautions. North America and Europe resorted more to reverse transcriptase-polymerase chain reaction (RT-PCR) for screening asymptomatic patients. High-prevalence countries showed a higher use of PAPRs. The medium-prevalence group reported lower RT-PCR testing for symptomatic cases, and the high-prevalence group used it significantly more in asymptomatic cases.Nineteen respondents reported transmission of COVID-19 to healthcare personnel during EES, with a higher rate of transmission among countries classified as having a medium prevalence of COVID-19. These specific respondents (medium prevalence) also reported a lower use of airborne PPE. In the cases of healthcare transmission, the patient was reportedly asymptomatic 32% of the time. CONCLUSIONS: This survey gives an overview of EES practices during the SARS-CoV-2 pandemic. Intensified preoperative screening, even in asymptomatic patients, RT-PCR for all symptomatic cases, and an increased use of airborne PPE is associated with decreased reports of COVID-19 transmission during EES.

Endoscopic transnasal transmaxillary approach to the upper parapharyngeal space and the skull base.

PURPOSE: Treatment of tumors arising in the upper parapharyngeal space (PPS) or the floor of the middle cranial fossa is challenging. This study aims to present anatomical landmarks for a combined endoscopic transnasal and anterior transmaxillary approach to the upper PPS and the floor of the middle cranial fossa and to further evaluate their clinical application. METHODS: Dissection of the upper PPS using a combined endoscopic endonasal transpterygoid and anterior transmaxillary approach was performed in six cadaveric heads. Surgical landmarks associated with the approach were defined. The defined approach was applied in patients with tumors involving the upper PPS. RESULTS: The medial pterygoid muscle, tensor veli palatini muscle and levator veli palatini muscle were key landmarks of the approach into the upper PPS. The lateral pterygoid plate, foramen ovale and mandibular nerve were important anatomical landmarks for exposing the parapharyngeal segment of the internal carotid artery through a combined endoscopic transnasal and anterior transmaxillary approach. The combined approach provided a better view of the upper PPS and middle skull base, allowing for effective bimanual techniques and bleeding control. Application of the anterior transmaxillary approach also provided a better view of the inferior limits of the upper PPS and facilitated control of the internal carotid artery. CONCLUSIONS: Improving the knowledge of the endoscopic anatomy of the upper PPS allowed us to achieve an optimal approach to tumors arising in the upper PPS. The combined endoscopic transnasal and anterior transmaxillary approach is a minimally invasive alternative approach to the upper PPS.

Endoscopic transnasal skull base surgery: pushing the boundaries.

The endoscopic endonasal approach (EEA) has significantly evolved since its initial uses in pituitary and sinonasal surgery. The literature is filled with reports and case series demonstrating efficacy and advantages for the entire ventral skull base. With competence in 'minimally invasive' parasellar approaches, larger and more complex approaches were developed to utilize the endonasal corridor to create maximally invasive endoscopic skull base procedures. The challenges of these more complex endoscopic procedures include a long learning curve and navigating in a narrow corridor; reconstruction of defects presented new challenges and early experience revealed a significantly higher risk of cerebrospinal fluid leak. Despite these challenges, there are many benefits to the EEA including avoidance of brain and neurovascular retraction, improved visualization, a direct corridor onto many tumors and the two-surgeon approach. Most importantly, the EEA provides a midline corridor to directly access tumors, which displace critical neurovascular structures laterally, giving it an inherent advantage of minimizing any manipulation of these structures and thus decreasing their potential injury.

Endoscopic endonasal approach for pituitary adenomas: a series of 555 patients.

PURPOSE: To report the results of a consecutive series of patients who underwent an endoscopic endonasal approach (EEA) for resection of a pituitary adenoma and compare them to previous series of microscopic and endoscopic approaches. METHODS: A retrospective review of clinical and radiographic outcomes of a consecutive series of patients operated at our center between 2002 and 2011 was performed. RESULTS: 555 patients underwent an EEA for removal of a pituitary adenoma. The mean follow up was 3.1 years (range 3 months to 9.5 years); 36 were lost to follow up. Ninety-one (17.5%) harbored recurrent adenomas. An expanded approach to reach the supra-, para- and infra-sellar spaces was employed in 290 patients (55.9%). Reconstruction with a nasal septal flap was used in 238 cases (65.6%). The rate of gross total resection was 65.3% in the 359 patients with non-functioning adenomas. The remission rates with EEA alone were 82.5% in the 57 ACTH-secreting adenomas, 65.3% in the 49 GH-secreting adenomas and 54.7% in the 53 prolactinomas. Of the 237 patients presenting with visual loss, 190 (80.2%) improved or normalized, 41 (17.3%) remained unchanged and 4 (1.7%) experienced transient visual deterioration due to postoperative apoplexy. In addition, no patient without preexisting visual loss suffered new visual decline. The overall post-operative CSF leak rate was 5% and this decreased to 2.9% after the introduction of reconstruction with the naso-septal flap. Two patients (0.3%) had an ICA injury. CONCLUSIONS: The EEA is a safe and effective way to surgically approach pituitary adenomas, particularly in recurrent tumors, those with supra-sellar extension or cavernous sinus invasion. The remission and complication rates are comparable or favorable compared with those reported in previous series of microscopic and endoscopic approaches.

Endoscopic endonasal surgery for olfactory groove meningiomas: outcomes and limitations in 50 patients.

OBJECT: Recently, endoscopic endonasal surgery (EES) has been introduced in the management of skull base tumors, with constantly improving outcomes and increasing indications. The authors retrospectively reviewed the effectiveness of EES in the management of olfactory groove meningiomas. METHODS: Between February 2003 and December 2012, 50 patients (64% female) with olfactory groove meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, clinical outcome, complications, and limitations of this approach. RESULTS: Forty-four patients presented with primary tumors, whereas six were previously treated elsewhere. The patients' mean age was 57.1 years (range 27-88 years). Clinical presentation included altered mental status (36%), visual loss (30%), headache (24%), and seizures (20%). The mean maximum tumor diameter was 41.6 mm (range 18-80 mm). All patients underwent EES, which was performed in stages in 18 giant tumors. Complete tumor resection (Simpson Grade I) was achieved in 66.7% of the 45 patients in whom it was the goal, and 13 (28.9%) had neartotal resection (> 95% of the tumor). Tumor size, calcification, and absence of cortical cuff from vasculature were significant factors that influenced the degree of resection (p = 0.002, p = 0.024, and p = 0.028, respectively). Tumor residual was usually at the most lateral and anterior tumor margins. Following EES, mental status was improved or normalized in 77.8% of the cases, vision was improved or restored in 86.7%, and headaches resolved in 83.3%. There was no postoperative deterioration of presenting symptoms. Complications were increased in tumors > 40 mm and included CSF leakage (30%), which was significantly associated with lobular tumor configuration (p = 0.048); pulmonary embolism/deep vein thrombosis, more commonly in elderly patients (20%); sinus infections (10%); and delayed abscess months or years after EES (6%). One patient had an intraoperative vascular injury resulting in transient hemiparesis (2%). There were no perioperative deaths. During a mean follow-up period of 32 months (median 22 months, range 1-115 months), 1 patient underwent repeat EES for tumor regrowth. CONCLUSIONS: Endoscopic endonasal surgery has shown good clinical outcomes regardless of patient age, previous treatment, or tumor characteristics. Tumor size > 40 mm, calcification, and absence of cortical vascular cuff limit GTR with EES; in addition, large tumors are associated with increased postoperative complications. Significant lateral and anterior dural involvement may represent indications for using traditional craniotomies for the management of these tumors. Postoperative CSF leakage remains a problem that necessitates innovations in EES reconstruction techniques.

Survey of Skull Base Surgeons' Approach to Carcinomas Involving the Cavernous Sinus.

Objectives Carcinomas involving the cavernous sinus are challenging to resect without compromising important neurovascular structures. Given the morbidity and mortality of these operations, radiotherapy, chemotherapy, and immunotherapy are more often utilized. Although limited to case reports and small series, radical resection of the cavernous sinus has been proposed. We aimed to study surgeons' willingness to perform cavernous sinus exenteration (CSE) under different clinical scenarios. Design, Setting, Participants, Main Outcome Measures We conducted an online survey from April to July 2021 among members of the Skull Base Congress and the North American Skull Base Society. Descriptive statistics were used to analyze the main outcome measure of willingness to perform CSE . Results The analytic sample ( n = 112) included 54% otolaryngologists and 43% neurosurgeons. Eighty-six percent practiced in an academic setting. Surgeons' willingness to perform CSE was low (6-16% under different clinical scenarios), citing a belief that they could not obtain oncologic margins and the procedure's morbidity. Forty-five percent had at least one patient undergo CSE with 72% of patients surviving no more than 2 years. Complications included chronic intractable pain, cerebrospinal fluid leak, cerebrovascular accident, and/or intraoperative/postoperative death within 30 days. Sixty percent agreed that the availability of immunotherapy and genomic sequencing has affected their willingness to offer CSE. Conclusion Overall, most of the surgeons surveyed were unwilling to offer CSE for carcinomatous cavernous sinus invasion, whether for primary disease or recurrence. Given the rarity of these tumors and the limited data on CSE, these results may provide more information for clinicians and patients for these treatment decisions.

Endoscopic Endonasal Far-Medial Approach: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: Endoscopic endonasal far-medial approach provides an effective and safe corridor to access the parasagittal structures of the lower clivus such as the medial jugular tubercle (JT) and occipital condyle (OC) for lesions that displace neurovascular structures laterally. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Parapharyngeal internal carotid arteries (ICAs) run posterolateral to the eustachian tubes and lateral to the OC. The supracondylar groove is a superficial landmark for the hypoglossal canal, which divides the lateral extension of clivus into the JT and OC. ESSENTIAL STEPS OF THE PROCEDURE: Typically, approach starts with opening of the sphenoid sinus to localize the paraclival ICA. An "inverted U" rhinopharyngeal (RP) flap exposing the supracondylar groove and lower clivus. Doppler and navigation can confirm the course of the ICA. Drilling is started in the midline in the lower clivus and extended laterally to expose the hypoglossal canal, JT, and OC. PITFALLS/AVOIDANCE OF COMPLICATIONS: Neurovascular injuries can be avoided by using intraoperative Doppler and nerve stimulator. Multilayer reconstruction with vascularized nasoseptal (NSF) and RP flaps minimize postoperative cerebrospinal fluid leak. VARIANTS AND INDICATIONS FOR THEIR USE: The contralateral transmaxillary approach provides an increased angle of access behind foramen lacerum and the petrous ICA.The endoscopic endonasal far-medial approach can be used for a variety of pathologies, including petroclival or JT meningiomas, chordomas and chondrosarcomas, and hypoglossal schwannomas, inferiorly extending cholesterol granulomas and even rare, ventral posterior inferior cerebellar artery aneurysms.The patients consented to the procedure.

Anteromedial Petrous (Gardner's) Triangle: Surgical Anatomy and Relevance for Endoscopic Endonasal Approach to the Petrous Apex and Petroclival Region.

BACKGROUND AND OBJECTIVES: Triangular corridors have been used as reliable surgical entry points for open transcranial approaches to the petrous apex (PA) and petroclival region (PCR). The endoscopic endonasal approaches have grown rapidly in the last decade, and the indications have advanced. The knowledge of accurate and reliable anatomic landmarks through endoscopic endonasal route is essential and remain to be established. The purpose of this study was to describe the feasibility and surgical exposure of the anteromedial petrous (Gardner's) triangle as a novel corridor to the PA and PCR. METHODS: Five anatomic specimens were dissected. The PA and PCR were accessed through endoscopic endonasal approaches and contralateral transmaxillary approach. The limits of the anteromedial petrous (Gardner's) triangle were identified and dissected and associated measurements performed. RESULTS: The dissection was divided into 6 steps. The limits of the anteromedial petrous (Gardner's) triangle were identified and defined by the paraclival internal carotid artery anterolaterally, the abducens nerve posteromedially, and the petroclival synchondrosis inferiorly. Three lines were established following the limits of the triangle. The mean distance of the anterolateral limit was 10.03 mm (SD = 0.94), of the posteromedial limit was 20.06 mm (SD = 2.90), and of the inferior limit was 17.99 mm (SD = 2.99). The mean area was 87.56 mm 2 (SD = 20.06). The 3 anatomic landmarks with a critical role to safely define the triangle were the pterygosphenoidal fissure, the petrosal process of the sphenoid bone, and the petroclival synchondrosis. CONCLUSION: The anteromedial (Gardner's) triangle is a well-defined bone corridor which provides access to the entire petrous bone and petroclival junction through endoscopic endonasal route. Regardless of the anatomic variations or tumor location, the landmarks of the abducens nerve, paraclival internal carotid artery, and petroclival synchondrosis are key for understanding lateral access to tumors extending from the clivus.

DOTATATE PET Imaging in Olfactory Neuroblastoma and Association with SSTR Expression.

Introduction Olfactory neuroblastoma (ONB), or esthesioneuroblastoma, is a rare neuroectodermal tumor of the nasal cavity and paranasal sinuses. Most of these tumors express somatostatin receptors (SSTRs), providing a potential target for radionuclide imaging with Ga-68 DOTATATE. However, this imaging modality has not been extensively studied in ONB. Methods We conducted a retrospective chart review of 96 endoscopic endonasal skull base surgery cases for ONB performed at our institution between 2000 and 2021. Histo (H) scores were assigned to each tumor and normalized DOTATATE standardized uptake values (nSUVs) were measured as well. Results Nine patients (5 males and 4 females) with ONB were ultimately included in the study. The average age of the patients was 50 years. All ONBs had a positive SSTR2 expression (H-score > 105; mean: 180). All ONBs showed DOTATATE avidity (mean nSUV for ONB: 6.7). However, there was no correlation between H-score and nSUV, with an r 2 of 0.24 ( p = 0.18). Conclusion Our study shows that SSTR2 expression is found in all ONBs with associated DOTATATE avidity, which may serve as a valuable imaging modality to monitor for recurrent and metastatic disease in ONB.

The Impact of Surgical Telementoring on Reducing the Complication Rate in Endoscopic Endonasal Surgery of the Skull Base.

BACKGROUND: Pituitary adenomas represent the most common pituitary disorder, with an estimated prevalence as high as 20%, and they can manifest with hormone hypersecretion or deficiency, neurological symptoms from mass effect, or incidental findings on imaging. Transsphenoidal surgery, performed either microscopically or endoscopically, allows for a better extent of resection while minimising the associated risk in comparison to the transcranial approach. Endoscopy allows for better visualisation and improvement in tumour resection with an improved working angle and less nasal morbidity, making it likely to become the preferred surgical treatment for pituitary neoplasms. The learning curve can be aided by telementoring. METHODS: We retrospectively analysed the clinical records of 94 patients who underwent an endoscopic endonasal resection of a pituitary neoplasm between the years 2011 and 2023 at Maribor University Medical Centre in Slovenia. Remote surgical telementoring over 3 years assisted with the learning curve. RESULTS: The proportion of complication-free patients significantly increased over the observed period (60% vs. 79%). A gradual but insignificant increase in the percentage of patients with improved endocrine function was observed. Patients' vision improved significantly over the observed period. By gaining experience, the extent of gross total tumour resection increased insignificantly (67% vs. 79%). CONCLUSIONS: Telementoring for the endoscopic endonasal approach to pituitary neoplasms enables low-volume centres to achieve efficiency, decreasing rates of postoperative complications and increasing the extent of tumour resection.