Identifying Tumor Microenvironment Biomarkers in Adherent and Cystic Vestibular Schwannomas.

OBJECTIVE: A subset of vestibular schwannomas (VSs), including cystic tumors, have higher postoperative morbidity because of the presence of adhesions between the tumor, facial nerve (FN), and brainstem. We identify tumor microenvironment (TME) biomarkers to better classify these tumors and predict the degree of tumor adherence. STUDY DESIGN: Retrospective case series. SETTING: Tertiary skull base referral center. METHODS: Adult patients with cystic and solid VS matched in tumor size who underwent surgical resection were included. Expressions of seven biomarkers of extracellular matrix remodeling and tumor immune response were quantified via immunohistochemistry. The distribution of CD45+ immune cells was evaluated in intratumoral and perivascular compartments. The degree of tumor adherence was categorized as none, adherent to FN, or adherent to both FN and brainstem. RESULTS: Twenty-eight patients were included. Cystic VSs were significantly more adherent than solid VSs ( p = 0.02). Patients with adherent VS had shorter duration of symptoms and were more likely to undergo subtotal resection. In solid tumors, matrix metalloproteinase (MMP)-2 expression ( p = 0.02) and CD163+ macrophage infiltration ( p = 0.007) were correlated with tumor size. Linear discriminant analyses (LDAs) demonstrated MMP-2, MMP-14, CD80, CD163, and perivascular CD45 to be individually predictive of the degree of tumor adherence (all p < 0.05), with perivascular CD45 being the best independent predictor ( p = 0.005). An LDA model including these biomarkers demonstrated 100% accurate discrimination of all three levels of tumor adherence ( p = 0.04). CONCLUSIONS: Adherent VS have a distinct proinflammatory TME characterized by elevated MMP expression, enrichment of tumor-associated macrophages, and perivascular immune cell infiltration.

Comparison of Postoperative Outcomes in Cystic Versus Solid Vestibular Schwannoma in a Multi-institutional Cohort.

OBJECTIVE: Cystic vestibular schwannomas (cVSs) have more variable and less favorable clinical outcomes after microsurgical resection compared with solid VS (sVS). This study compares the preoperative presentation and postoperative outcomes between cVS and sVS. STUDY DESIGN: Retrospective cohort study. SETTING: Two tertiary skull base referral centers. METHODS: Consecutive adult patients who underwent VS resection from 2016 to 2021 were included. Univariate and multivariate analyses compared differences in baseline symptoms and postoperative outcomes between cVS and sVS. RESULTS: There were a total of 315 patients (64% female; mean age, 54 yrs) and 46 (15%) were cystic. cVS were significantly larger than sVS (maximum diameter, 28 vs. 18 mm, p < 0.001) and had higher rates of dysphagia and dysphonia preoperatively (p < 0.02). cVSs were more likely to undergo translabyrinthine resection (76 vs. 50%, p = 0.001) and have a higher rate of subtotal resection (STR) compared with sVS (30 vs. 13%, p = 0.003). At latest follow-up, fewer cVS achieved good facial nerve (FN) outcome (House-Brackmann [HB] I/II) (80 vs. 90%, p = 0.048). Subanalysis of cVS and sVS matched in tumor size, and surgical approach did not show differences in the rate of STR or FN outcomes (HB I/II, 82 vs. 78%, p = 0.79). CONCLUSION: In this large multi-institutional series, cVSs represent a distinct entity and are characterized by larger tumor size and higher incidence of atypical symptoms. Although cVSs were more likely to undergo STR and portend worse FN outcomes than sVSs, this may be due to their larger tumor size rather than the presence of the cystic component.

A modern approach to olfactory groove meningiomas.

OBJECTIVE: Management of olfactory groove meningiomas (OGMs) has changed significantly with the advances in extended endoscopic endonasal approaches (EEAs), which is an excellent approach for patients with anosmia since it allows early devascularization and minimizes retraction on the frontal lobes. Craniotomy is best suited for preservation of olfaction. However, not infrequently, a tumor presents after extending outside the reach of an EEA and a solely transcranial approach would require manipulation and retraction of the frontal lobes. These OGMs may best be treated by a staged EEA-craniotomy approach. In this study the authors' goal was to present their case series of patients with OGMs treated with their surgical approach algorithm. METHODS: The authors conducted an IRB-approved, nonrandomized historic cohort including all consecutive cases of OGMs treated surgically between 2010 and 2020. Patient demographic information, presenting symptoms, operative details, and complications data were collected. Preoperative and postoperative tumor and T2/FLAIR intensity volumes were calculated using Visage Imaging software. RESULTS: Thirty-one patients with OGMs were treated (14 craniotomy only, 11 EEA only, and 6 staged). There was a significant difference in the distribution of patients presenting with anosmia and visual disturbance by approach. Tumor size was significantly correlated with preoperative vasogenic edema. Gross-total resection was achieved in 90% of cases, with near-total resection occurring twice with EEA and once with a staged approach. T2/FLAIR hyperintensity completely resolved in 90% of cases and rates did not differ by approach. Complication rates were not significantly different by approach and included 4 CSF leaks (p = 0.68). CONCLUSIONS: A staged approach for the management of large OGMs with associated anosmia and significant lateral extension is a safe and effective option for surgical management. Through utilization of the described algorithm, the authors achieved a high rate of GTR, and this strategy may be considered for large OGMs.

Endoscopic Multiport Approach for Exenteration of the Infratemporal Fossa.

OBJECTIVE: To demonstrate anatomic relationships pertinent to the endoscopic multiport approach to the infratemporal fossa (ITF). Discuss advantages and limitations of each individual approach. STUDY DESIGN: Cadaveric study. METHODS: Endoscopic and endoscopic-assisted endonasal transpterygoid, sublabial transmaxillary, endoscopic transorbital, and endoscopic transoral approaches to accessing the ITF were completed in five silicone-injected fresh cadaveric specimens (10 sides) with the assistance of 0, 30, and 450 rods-lens endoscopes. Image guidance was used to confirm and document the anatomical relationships encountered in each approach. RESULTS: The endonasal endoscopic transpterygoid approach provides better visualization and more direct exposure to median structures. Endoscopic-assisted sublabial transmaxillary approach enhances the field of exposure, angle of attack, and ease of instrumentation to the lateral part of the ITF. Endoscopic-assisted transorbital approach via the inferior orbital fissure provided cephalic and anterior access. Endoscopic-assisted transoral approach complements the access to lesions extending inferior to the hard palate or far lateral to the mandibular condyle. CONCLUSIONS: A combination of minimal access infratemporal approaches can provide adequate exposure of the entire ITF while avoiding some of the morbidity associated with open approaches. LEVEL OF EVIDENCE: NA Laryngoscope, 133:1367-1374, 2023.

Intraoperative Predictor of Remission in Cushing Disease.

BACKGROUND: Cushing disease represents a challenge for neurosurgeons, with high recurrence rates reported. Characteristics associated with remission are incompletely understood; thus, an intraoperative predictor for outcome would be valuable for assessing resection of adrenocorticotropic hormone (ACTH) secreting tissue. OBJECTIVE: To evaluate whether intraoperative ACTH measurement could predict outcome after surgery for Cushing disease. METHODS: Retrospective cohort study of 55 consecutive encounters with Cushing disease who had peripheral plasma ACTH levels measured intraoperatively before, during, and after tumor resection. The primary outcome measure was remission, defined by either 2 negative 24-hour urine free cortisol or 2 negative midnight salivary cortisol measurements. A logistic regression machine learning model was generated using recursive feature elimination. RESULTS: Fifty-five operative encounters, comprising 49 unique patients, had a mean follow-up of 2.73 years (±2.11 years) and a median follow-up of 2.07 years. Remission was achieved in 69.1% (n = 38) of all operations and in 78.0% (n = 32) of those without cavernous sinus invasion. The final ACTH level measured intraoperatively correctly predicted outcome (area under the curve = 0.766; P value = .002). The odds ratio of remission in patients with the lowest quartile vs highest quartile final intraoperative ACTH was 23.4 ( P value = .002). Logistic regression machine learning model resulted in incorporating postoperative day 1 morning cortisol, final intraoperative ACTH that predicted outcome with an average area under the curve of 0.80 ( P = .0027). CONCLUSION: Intraoperative ACTH may predict outcome after surgery in Cushing disease; furthermore, investigation is warranted.

Pituitary Stalk Stretch Predicts Postoperative Diabetes Insipidus After Pituitary Macroadenoma Transsphenoidal Resection.

BACKGROUND: Manipulation of the pituitary stalk, posterior pituitary gland, and hypothalamus during transsphenoidal pituitary adenoma resection can cause disruption of water electrolyte regulation leading to diabetes insipidus (DI). OBJECTIVE: To determine whether pituitary stalk stretch is an independent risk factor for postoperative DI after pituitary adenoma resection. METHODS: A retrospective review was performed of patients undergoing endoscopic endonasal resection of pituitary macroadenoma between July 2010 and December 2016 by a single neurosurgeon. We analyzed preoperative and postoperative imaging metrics to assess predictors for postoperative DI. RESULTS: Of the 234 patients undergoing resection, 41 (17.5%) developed postoperative DI. DI was permanent in 10 (4.3%) and transient in 31 (13.2%). The pituitary stalk stretch, measured as the change in stalk length from preoperative to postoperative imaging, was greater in the DI compared with the non-DI group (10.1 mm vs 5.9 mm, P < .0001). The pituitary stalk stretch was associated with DI with significant difference in mean pituitary stalk stretch between non-DI group vs DI group (5.9 mm vs 10.1 mm, P < .0001). Multivariate analysis revealed that pituitary stalk stretch >10 mm was a significant independent predictor of postoperative DI [odds ratios = 2.56 (1.10-5.96), P = .029]. When stratified into transient and permanent DI, multivariable analysis showed that pituitary stalk stretch >10 mm was a significant independent predictor of transient DI [odds ratios = 2.71 (1.0-7.1), P = .046] but not permanent DI. CONCLUSION: Postoperative pituitary stalk stretch after transsphenoidal pituitary adenoma surgery is an important factor for postoperative DI. We propose a reconstruction strategy to mitigate stalk stretch.

Intraoperative Prediction of Long-Term Remission in Acromegaly.

BACKGROUND: The features of long-term remission in acromegaly adenomectomy are incompletely understood. An intraoperative predictor for long-term outcome would be valuable for assessing resection of growth hormone (GH)-secreting tumors in real-time. OBJECTIVE: To evaluate whether intraoperative GH measurement could predict long-term outcomes for acromegaly. METHODS: In 47 patients, peripheral blood GH levels were measured thrice intraoperatively: once before tumor dissection, once during tumor dissection, and once after tumor dissection. Long-term remission was defined by age-appropriate, normalized insulin-like growth factor-1 at most recent follow-up and a random GH less than 1.0 ng/mL. Patients were only considered to be in long-term remission without the use of postoperative medical therapy for acromegaly or radiation therapy. RESULTS: The median length of follow-up was 4.51 (range: 0.78-9.80) years. Long-term remission was achieved in 61.7% (29/47) of operations. Like previous studies, cavernous sinus invasion (odds ratio [OR]: 0.060; 95% CI: 0.014-0.260; P value < .01), suprasellar extension (OR: 0.191; 95% CI: 0.053-0.681; P value<.01), and tumor size greater than 1 cm (OR: 0.177; 95% CI: 0.003-0.917; P value = .03) were associated with not being in long-term remission. The minimum GH measured intraoperatively predicted long-term outcome (area under the curve: 0.7107; 95% CI: 0.537-0.884; P value < .01). The odds ratio of remission in patients with the lowest quartile minimum intraoperative GH compared with patients with the highest quartile minimum intraoperative GH was 27.0 (95% CI: 2.343-311.171; P value < .01). CONCLUSION: Minimum intraoperative GH may predict long-term outcome for acromegaly, which in principle could provide the pituitary neurosurgeon with real-time feedback and inform intraoperative decision making.

Machine Learning-Based Analysis and Prediction of Unplanned 30-Day Readmissions After Pituitary Adenoma Resection: A Multi-Institutional Retrospective Study With External Validation.

BACKGROUND: Unplanned readmission after transsphenoidal resection of pituitary adenoma can occur in up to 10% of patients but is unpredictable. OBJECTIVE: To develop a reliable system for predicting unplanned readmission and create a validated method for stratifying patients by risk. METHODS: Data sets were retrospectively collected from the National Surgical Quality Improvement Program and 2 tertiary academic medical centers. Eight machine learning classifiers were fit to the National Surgical Quality Improvement Program data, optimized using Bayesian parameter optimization and evaluated on the external data. Permutation analysis identified the relative importance of predictive variables, and a risk stratification system was built using the trained machine learning models. RESULTS: Readmissions were accurately predicted by several classification models with an area under the receiving operator characteristic curve of 0.76 (95% CI 0.68-0.83) on the external data set. Permutation analysis identified the most important variables for predicting readmission as preoperative sodium level, returning to the operating room, and total operation time. High-risk and medium-risk patients, as identified by the proposed risk stratification system, were more likely to be readmitted than low-risk patients, with relative risks of 12.2 (95% CI 5.9-26.5) and 4.2 (95% CI 2.3-8.7), respectively. Overall risk stratification showed high discriminative capability with a C-statistic of 0.73. CONCLUSION: In this multi-institutional study with outside validation, unplanned readmissions after pituitary adenoma resection were accurately predicted using machine learning techniques. The features identified in this study and the risk stratification system developed could guide clinical and surgical decision making, reduce healthcare costs, and improve the quality of patient care by better identifying high-risk patients for closer perioperative management.

Morphometric comparison of Fisch type A and endoscopic endonasal far-medial supracondylar approaches to the jugular foramen.

OBJECTIVE: The jugular foramen (JF) is one of the most complex and challenging skull base regions to approach surgically. The extreme medial approach to access the JF provides the approach angle from an anterior direction and does not require dissection and sacrifice of the jugular bulb (JB) to reach the pars nervosa. The authors compared the Fisch type A approach to the extreme medial approach to access the JF and evaluated the usefulness of the extreme medial approach. METHODS: This study was performed at the Anatomical Laboratory for Visuospatial Innovations in Otolaryngology and Neurosurgery of The Ohio State University. For the comparison of surgical maneuverability and visualization, two angles were measured: 1) the angle of attack (AoA), defined as the widest angle of movement achieved with a straight dissector; and 2) the angle of endoscopic exposure (AoEE), defined as the widest angle of movement in the nasal cavity. The differences in eustachian tube (ET) management, approach angle, surgical maneuverability, and surgical application of the Fisch type A approach to the extreme medial approach were compared. RESULTS: There was no difference between ET mobilization and transection regarding cranial-caudal (CC) or medial-lateral (ML) AoA (p = 0.646). The CC-AoA of the Fisch type A approach was significantly wider than the CC-AoA of the extreme medial approach (p = 0.001), and the CC-AoEE was significantly wider than the CC-AoA of the extreme medial approach (p < 0.001). There was no significant difference between the CC-AoA of the Fisch type A approach and the CC-AoEE. The ML-AoA of the Fisch type A approach was significantly wider than the ML-AoA of the extreme medial approach (p = 0.033), and the ML-AoEE was significantly wider than ML-AoA in the extreme medial approach (p < 0.001). The ML-AoEE was significantly wider than the ML-AoA in the Fisch type A approach (p = 0.033). CONCLUSIONS: The surgical maneuverability of the extreme medial approach was not inferior to that of the Fisch type A approach. The extreme medial approach can provide excellent surgical field visualization, while preserving the JB. Select cases of chordomas, chondrosarcomas, and JF schwannomas should be considered for an extreme medial approach. These two approaches are complementary, and a case-by-case detailed analysis should be conducted to decide the best approach.

Complications after 1002 endoscopic endonasal approach procedures at a single center: lessons learned, 2010-2018.

OBJECTIVE: The endoscopic endonasal approach (EEA) has evolved into a mainstay of skull base surgery over the last two decades, but publications examining the intraoperative and perioperative complications of this technique remain scarce. A prior landmark series of 800 patients reported complications during the first era of EEA (1998-2007), parallel to the development of many now-routine techniques and technologies. The authors examined a single-institution series of more than 1000 consecutive EEA neurosurgical procedures performed since 2010, to elucidate the safety and risk factors associated with surgical and postoperative complications in this modern era. METHODS: After obtaining institutional review board approval, the authors retrospectively reviewed intraoperative and postoperative complications and their outcomes in patients who underwent EEA between July 2010 and June 2018 at a single institution. RESULTS: The authors identified 1002 EEA operations that met the inclusion criteria. Pituitary adenoma was the most common pathology (n = 392 [39%]), followed by meningioma (n = 109 [11%]). No patients died intraoperatively. Two (0.2%) patients had an intraoperative carotid artery injury: 1 had no neurological sequelae, and 1 had permanent hemiplegia. Sixty-one (6.1%) cases of postoperative cerebrospinal fluid leak occurred, of which 45 occurred during the original surgical hospitalization. Transient postoperative sodium dysregulation was noted after 87 (8.7%) operations. Six (0.6%) patients were treated for meningitis, and 1 (0.1%) patient died of a fungal skull base infection. Three (0.3%) patients died of medical complications, thereby yielding a perioperative 90-day mortality rate of 0.4% (4 deaths). High-grade (Clavien-Dindo grade III-V) complications were identified after 103 (10%) EEA procedures, and multivariate analysis was performed to determine the associations between factors and these more serious complications. Extradural EEA was significantly associated with decreased rates of these high-grade complications (OR [95% CI] 0.323 [0.153-0.698], p = 0.0039), whereas meningioma pathology (OR [95% CI] 2.39 [1.30-4.40], p = 0.0053), expanded-approach intradural surgery (OR [95% CI] 2.54 [1.46-4.42], p = 0.0009), and chordoma pathology (OR [95% CI] 9.31 [3.87-22.4], p < 0.0001) were independently associated with significantly increased rates of high-grade complications. CONCLUSIONS: The authors have reported a large 1002-operation cohort of EEA procedures and associated complications. Modern EEA surgery for skull base pathologies has an acceptable safety profile with low morbidity and mortality rates. Nevertheless, significant intraoperative and postoperative complications were correlated with complex intradural procedures and meningioma and chordoma pathologies.

Soft Gasket Seal Reconstruction After Endoscopic Endonasal Transtuberculum Resection of Craniopharyngiomas.

BACKGROUND: The expanded endoscopic endonasal approach (EEA) is currently well accepted for a variety of ventral skull base tumors. Such an approach often results in a transdural defect and intraoperative cerebrospinal fluid (CSF) leak, and adequate reconstruction is necessary to prevent postoperative CSF leak and its complications. Reconstruction is usually performed using a variety of materials along with the nasoseptal flap. OBJECTIVE: This work's aim is to describe a new reconstructive technique called the "soft gasket seal" (SGS) in detail and compare it with the standard reconstructive technique at our institution for craniopharyngiomas operated via transtuberculum EEA. METHODS: A retrospective chart review was achieved to identify patients who underwent transtubercular EEA for craniopharyngioma between 2010 and 2018, by the same neurosurgical and otolaryngology team using either the SGS or standard reconstructive technique. RESULTS: Of 36 patients who met criteria and were considered for analysis, 15 of them underwent SGS reconstruction and 21 had standard reconstruction. There were 16 female (44%) and 20 male (56%) patients. The median age was 42.2 ± 20.9 years. The rate of postoperative CSF leak in the group of patients treated with the standard technique was 14.2% and 6.6% in the SGS group (odds ratio 0.43 [confidence interval 95% 0.007-6.15], P = 0.62). CONCLUSIONS: The SGS technique provides a simple reconstructive technique in conjunction with the nasoseptal flap, showing a tendency of lower complications when compared with our standard technique while avoiding donor site morbidity. Such results are encouraging, but further studies are necessary to confirm these findings.

Simultaneous Endoscopic and Microscopic Visualization in Microvascular Decompression for Hemifacial Spasm.

BACKGROUND: Hemifacial spasm (HFS) is a socially limiting condition leading to decreased quality of life that can be treated with microvascular decompression (MVD). Endoscopy has been described as an adjunct to traditional microscopy for MVD, although the best visualization technique is debated. OBJECTIVE: To review the current literature on use of endoscopy in MVD for HFS and to describe the simultaneous microscopic and endoscopic visualization technique along with a video illustration. METHODS: Patients who underwent MVD for HFS were retrospectively reviewed from January 2011 to December 2019. The first set of patients in the series were done using traditional endoscopic assisted visualization, followed by a change in technique in the subsequent patients using the simultaneous endoscopic technique. The surgical technique is described as well as illustrated with a video. RESULTS: In total, 21 patients underwent 24 MVDs to treat HFS. The simultaneous endoscopic/microscopic technique was used in 48% of cases for visualization. All but one patient had resolution of their symptoms immediately after the procedure. In total, 7 patients had recurrence of HFS, with 4 (17%) resolving spontaneously and 3 (13%) ultimately undergoing redo MVD. Postoperatively 7 patients (29%) had transient complications that all resolved completely. There was no significant difference between the traditional alternating microscopic and endoscopic technique with the simultaneous endoscopic microscopic technique. CONCLUSION: Endoscopic assistance during MVD for HFS is beneficial and may be streamlined by using the simultaneous microscope and endoscope visualization technique.

Endoscopic Endonasal Transtubercular Approach for Resection of Giant Pituitary Adenomas With Subarachnoid Extension: The "Second Floor" Strategy to Avoid Postoperative Apoplexy.

BACKGROUND: Giant pituitary adenomas (GPAs) with subarachnoid extension can be challenging to achieve a gross total resection through a single endonasal or transcranial approach, and any residual tumor is at risk for postoperative apoplexy. Intraoperative venous congestion of the suprasellar tumor can occur following resection of the sellar tumor, limiting tumor descent, and leading to suprasellar residual. We propose a technique for resecting the suprasellar component first, which we call the "second floor" strategy (SFS) for GPA. METHODS: A retrospective review of cases from 2010-2020 identified 586 endoscopic endonasal approaches (EEAs) for pituitary adenoma resection. We report the rate of postoperative apoplexy and describe the SFS technique used in 2 cases. RESULTS: Of 586 cases, 2 developed symptomatic postoperative apoplexy (0.3%), and a third transferred to our care after undergoing postoperative apoplexy. All 3 cases had subarachnoid extension of a pituitary adenoma, underwent EEA, and had residual suprasellar tumor. All 3 had permanent morbidity due to the postoperative apoplexy including blindness, stroke, or death, despite undergoing reoperation. The SFS was used for reoperation on 1 of these patients and as a primary strategy in a fourth patient who presented with a GPA with subarachnoid extension. We describe the SFS technique and demonstrate it with a 2-dimensional operative video. CONCLUSIONS: Postoperative apoplexy of residual adenoma is a rare but serious complication after GPA resection. The proposed SFS allows early access to the suprasellar tumor and may improve the ability to safely achieve a gross total resection without need for additional procedures.

Impact of cerebrospinal fluid flow study in patients undergoing intrathecal chemotherapy via ventricular catheter reservoir.

PURPOSE: Leptomeningeal carcinomatosis (LMC) is a form of CNS cancer metastasis with severe morbidity. Intrathecal chemotherapy (ITC) administration through an implanted ventricular catheter reservoir (IVCR) is often utilized. Additionally, a nuclear imaging flow study can be performed prior to ITC administration to assess cerebrospinal fluid (CSF) flow. The clinical impact of a CSF flow study is unclear. METHODS: A retrospective chart review identified 31 patients with LMC that underwent IVCR placement between 2011 and 2019. Data extracted included patient demographics, nuclear imaging flow study, surgical complications, ITC toxicities and outcomes. RESULTS: Potential drug-induced neurologic toxicities (headache, nausea/vomiting, altered mental status, etc.) were noted in (n = 4/16) 25% of patients who underwent a flow study prior to initiation of ITC, compared to (n = 1/15) 6.6% of patients who did not undergo a flow study. Median overall survival (OS) was 4.0 and 32.8 months for the patients that underwent a flow study versus patients who did not, respectively (p < 0.01). The mean interval from IVCR implantation to initiation of ITC was 15.2 ± 8.5 days and 3.3 ± 3.0 days in patients who underwent CSF flow study and patients that did not, respectively (p < 0.0001). CONCLUSIONS: A flow study can provide information regarding CSF flow dynamics prior to initiation of ITC; however this might delay initiation of ITC which may negatively impact OS. Additionally, in our study patients that underwent a flow study had more ITC induced drug toxicity events compared to those that did not. Further studies are needed to clarify the role of CSF flow study in these patients.

An institutional review of hospital resource utilization and patient radiation exposure in shunted idiopathic intracranial hypertension.

Patients with idiopathic intracranial hypertension (IIH) frequently utilize healthcare services and undergo radiological studies to assess refractory headache symptoms despite cerebrospinal fluid diversion. To delineate the clinical utility of different imaging modalities and to estimate cumulative patient radiation exposure in shunted patients with IIH, we retrospectively reviewed 100 randomly selected patients with IIH and a prior cerebrospinal fluid diversion procedure treated at our institution between July 2010 and August 2018. Patients had an average of 16.3 office (SD ± 13.8), 12.4 emergency department (± 21.0), and 4.6 inpatient (± 5.1) encounters over an average 4.8 years of follow-up. Patients underwent an average of 9.0 head CTs (± 8.1), 10.3 shunt series x-rays (± 11.2), and 4.3 MRIs (± 3.7). Approximated radiation exposure per patient was 21.4 mSv (± 18.7). Radiological studies performed for acute symptoms usually demonstrated no actionable findings (82.5% CTs, 97.5% shunt series x-rays, and 79.6% MRIs). Shunted IIH patients undergo numerous radiological studies and are subject to considerable levels of radiation, yet imaging shows actionable findings in less than 10% percent of radiographic studies. IIH patients may benefit from radiation-reducing protocols and the use of alternative imaging to assess symptoms.

Bony landmarks in the endoscopic endonasal transoculomotor approach.

The endoscopic endonasal transoculomotor approach (EETA) has been recently described as a doorway to access the parapeduncular space and treat pituitary adenomas with oculomotor extension. Intraoperative identification of the oculomotor triangle endonasally is challenging and dissection can put the internal carotid artery (ICA) at risk. The aim of the present study is to find reliable landmarks that identify the oculomotor triangle (OCMT) during the EETA and protect the ICA from injury. Several lines were defined for calculations. Among them, one oblique line that extends from the inferior margin of the lateral orbital canal recess to the vidian canal was named the clinoid-to-vidian line (CVL), while a vertical line that extends over the most medial point of the paraclival ICA was titled the sagittal paraclival line (SPL). Anatomic relationships between the OCMT to these lines were assessed in 7 cadaveric heads. The intersecting point between the CVL and SPL is located within 2 mm of the center of the OCMT (mean 0.8 ± 0.5 mm), and 1.1 ± 0.8 mm medially and above the parasellar ICA. CVL and SPL are reliable landmarks during the EETA that can both protect the parasellar ICA and anatomically orientate to the blind spot that corresponds with the OCMT. We recommend starting dissection medial and superior to the CVL-SPL intersecting point, and carry the dissection laterally thereafter to avoid inadvertent injury of the ICA.

Endoscopic approaches to skull base malignancies affecting the anterior fossa.

Anterior skull base malignancies are rare and comprise distinct histological entities. Surgery encompasses the traditional craniofacial resections (CFR), and more recently, endoscopic endonasal approaches (EEA) or a hybrid cranioendoscopic (CEA) technique. Although the CFR is still considered the "gold-standard;" there is growing evidence supporting that EEA yield equivalent oncologic outcomes with less morbidity in well-selected cases. Therefore, this article aims to review the current state-of-art in addressing anterior cranial base malignancies using expanded endoscopic endonasal approaches (EEA) with particular references to surgical anatomy and nuances of hybrid cranioendoscopic techniques. Cadaveric dissections and illustrative cases are presented to detail our current surgical technique allied with tailored adjuvant therapies, and treatment strategies are further discussed based on tumor histology.

Postoperative 30-day emergency department utilization after 7294 cranial neurosurgery procedures at a tertiary neuroscience center.

OBJECTIVE: Hospital readmission and the reduction thereof has become a major quality improvement initiative in organized medicine and neurosurgery. However, little research has been performed on why neurosurgical patients utilize hospital emergency rooms (ERs) with or without subsequent admission in the postoperative setting. METHODS: This study was a retrospective, single-center review of data for all surgical cranial procedures performed from July 2013 to July 2016 in patients who survived to discharge. The study was approved by the institutional review board of the participating medical center. RESULTS: The authors identified 7294 cranial procedures performed during 6596 hospital encounters in 5385 patients. The rate of postoperative ER utilization within 30 days after surgical hospitalization across all procedure types was 13.1 per 100 surgeries performed. The two most common chief complaints were pain (30.7%) and medical complication (18.2%). After identification of relevant surgical and patient factors with univariable analysis, a multivariable backward elimination logistic regression model was constructed in which Ommaya reservoir placement (OR 2.65, p = 0.0008) and cranial CSF shunt placement (OR 1.40, p = 0.0001) were associated with increased ER utilization. Deep brain stimulation electrode placement (OR 0.488, p = 0.0004), increasing hospital length of stay (OR 0.935, p < 0.0001), and increasing patient age (OR 0.988, p < 0.0001) were associated with lower rates of postoperative ER utilization. One-half (50%) of ER visit patients were readmitted to the hospital. New/worsening neurological deficit chief complaint (OR 1.99, p = 0.0088), fever chief complaint (OR 2.41, p = 0.0205), altered mentation chief complaint (OR 2.71, p = 0.0002), patient chronic kidney disease (OR 3.31, p = 0.0037), brain biopsy procedure type (OR 3.50, p = 0.0398), and wound infection chief complaint (OR 31.4, p = 0.0008) were associated with increased rates of readmission to the hospital from the ER in multivariable analysis. CONCLUSIONS: The authors report the rates of and reasons for ER utilization in a large cohort of postoperative cranial neurosurgical patients. Factors identified were associated with both increased and decreased use of the ER after cranial surgery, as well as variables associated with readmission to the hospital after postoperative ER visitation. These findings may direct future quality improvement via prospective implementation of care pathways for high-risk procedures.

Outcome of the surgical decompression for traumatic optic neuropathy: a systematic review and meta-analysis.

There exists a persisting controversy regarding the indications for optic nerve surgical decompression (ONSD) in traumatic optic neuropathy (TON). A meta-analysis is warranted to help guiding therapeutic decisions and address gaps in knowledge. The authors conducted a search of PubMed and MEDLINE electronic databases. Primary endpoint was the improvement in the visual function with ONSD in comparison with the conservative management. Secondary endpoint was visual function improvement when surgery was performed within the first 7 days. A random effects model meta-analysis was conducted. Data from each study were used to generate log odds ratio and 95% confidence intervals, to compare post-operative visual improvement. Nine studies met the inclusion criteria for analysis, comprising 766 patients. Visual improvement occurred in 55% (198/360) of patients treated with ONSD, and in 40% (164/406) of those who underwent conservative treatment. Forest plot revealed significant differences in the visual function improvement among these two groups, although further analysis revealed the studies were heterogeneous (log OR, 0.81; CI, 0.07-1.55; I2, 62.8% p = 0.015). Overall, patients who underwent early surgery had better visual outcomes (log OR, 0.94; CI, 0.29-1.60; I2, 0% p = 0.9). ONSD is an effective technique to improve the outcome in the visual function in patients with TON. A lack of randomized controlled trial-and inherent surgical selection and publication bias-limits direct comparison between surgical decompression and conservative management. Suitably designed prospective cohort studies may be useful in identifying patients more likely to receive benefit from ONSD.

Management of large intraventricular meningiomas with minimally invasive port technique: a three-case series.

The use of minimally invasive transcranial ports for the resection of deep-seated lesions has been shown to be safe and effective. To date, most of the literature regarding the tubular retractors used in brain surgery is comprised of individual case reports that describe the successful resection of deep-seated lesions such as thalamic pilocytic astrocytomas, colloid cysts in the third ventricle, hematomas, and cavernous angiomas. The authors describe their experience using a tubular retractor system with three different cases involving large intraventricular meningiomas and examine radiographic and patient outcomes. A single-institution, retrospective case series was performed from a skull base database. Patients who underwent resection of intraventricular > 4-cm meningiomas with port technology were identified. The authors reviewed three cases to illustrate the feasibility of minimal access port surgery for the resection of these lesions. Complete resection was achieved in all cases. None of the patients developed permanent neurological deficits. There were no major complications related to surgery and no mortalities. Good clinical and surgical outcomes for atrium meningiomas can be achieved through the minimally invasive port technique and tumor size does not appear to be a limitation.