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This article discusses the establishment of a national pituitary surgical research platform called RAPID, which aims to improve patient care and surgical outcomes for pituitary disorders. The initial focus of the collaboration is on Cushing's disease. The study provides an overview of the patient cohort, surgical outcomes, and lays the foundation for future research. The data collected from nine academic pituitary centers shows that 528 patients with Cushing's disease were treated by 26 neurosurgeons from 2003 to 2023. The report highlights insights into surgical outcomes and disease recurrence rates across different surgeons and environments. The collaboration is expected to advance the standard of care for patients with pituitary disorders. [Extracted from the article]

Repair of spontaneous cerebrospinal fluid (CSF) fistulas in patients with invasive skull base prolactinomas represents a surgical challenge because of the many sites of potential leak around the tumor and the possibility of developing additional sites of leak as the tumor regresses on dopamine agonist therapy. Little has been published on effective methods for treating this problem. In this case, a vascularized nasoseptal flap was used to repair a spontaneous CSF leak in a 31-year-old male with an invasive prolactinoma who was commenced on dopamine agonist therapy. The patient underwent successful multilayer repair of the fistula with a nasoseptal vascularized flap and abdominal rectus fascia. After 3 months of follow-up, he has had no CSF leak. CSF fistulas caused by skull base prolactinomas can be repaired successfully using a vascularized nasoseptal flap. Long-term follow-up will determine the durability of this repair technique. [ABSTRACT FROM AUTHOR]

Background: The nasolacrimal duct resides in the wall of the medial nasal cavity and influences minimal access endoscopic transmaxillary approaches to the lateral skull base. We describe an algorithm for surgical approach selection on the basis of the relationship of the target lesion to a line drawn from the anterior nasal SEptum through the Nasolacrimal Duct to the lesion (i.e., SEND line). Methods: We use the SEND line to estimate the lateral extent in the endonasal middle meatal transmaxillary approach, where the surgeon has good surgical freedom without the use of angled instruments and endoscopes. Lesions with an epicenter lateral to the SEND line were addressed through a sublabial anterior antrostomy transmaxillary corridor. Tumors with a more medially located epicenter, such as those involving the lateral sphenoid sinus and pterygoid plates, were addressed through the endonasal middle meatal corridor. Extensive tumors involving both domains were addressed through a combination approach. Results: We describe three instructive cases in which the approach selection was determined in part by preoperative assessment of the location of the tumor relative to the SEND line. Conclusions: The endoscopic sublabial transmaxillary and endoscopic endonasal middle meatal transmaxillary approaches are complementary corridors to the anterior skull base that can be used independently or in combination. The location of the target lesion relative to the SEND line as determined on preoperative imaging can serve as a guide for surgical decision making. [ABSTRACT FROM AUTHOR]

To describe an intuitive and useful method for measuring the global impact of a medical scholar's research ideas by examining cross-border citations (CBCs) of peer-reviewed neurosurgical publications. Publication and citation data for a random sample of the top 50 most academically productive neurosurgeons were obtained from Scopus Application Programming Interface. We characterized an author-level global impact index analogous to the widely used h -index, the h global -index, defined as the number of published peer-reviewed manuscripts with at least the same number of CBCs. To uncover socioeconomic insights, we explored the h global -index for high-, middle-, and low-income countries. The median (interquartile range) number of publications and CBCs were 144 (62–255) and 2704 (959–5325), respectively. The median (interquartile range) h -index and h global -index were 42 (23–61) and 32 (17–38), respectively. Compared with neurosurgeons in the random sample, the 3 global neurosurgeons had the highest h global -indices in low-income countries at 17, 13, and 9, despite below-average h -index scores of 33, 38, and 19, respectively. This intuitive update to the h -index uses CBCs to measure the global impact of scientific research. The h global -index may provide insight into global diffusion of medical ideas, which can be used for social science research, author self-assessment, and academic promotion. [ABSTRACT FROM AUTHOR]

Background: Percutaneous thoracic pedicle screw fixation is challenging because of the complexity of the spinal anatomy and obscuration of normal surgical landmarks by soft tissue. We report a novel percutaneous technique in which intraoperative Iso-C C-arm navigation was used to treat complex thoracic spinal fractures. Methods: Between March and September 2007, percutaneous thoracic pedicle screw fixation was performed with the assistance of intraoperative Iso-C C-arm fluoroscopy in six patients (two males, four females; mean age = 33 years, range = 16-61 years) with unstable thoracic fractures. The accuracy of pedicle screw placement was assessed by postoperative computed tomography and graded according to the method of Youkilis et al. Results: Five patients had unstable acute traumatic fractures and one had an osteoporotic burst fracture. Altogether, 19 spinal segments (range = 2-4/patient) were fixated using 37 pedicle screws. Pedicle screw misplacement was grade II in 16% and grade III in 3%. None of the patients had neurologic consequences due to screw misplacement, and none required conversion to an open procedure or revision of hardware. There was one wound infection. Conclusion: Percutaneous thoracic pedicle screw fixation with intraoperative neuronavigation for the stabilization of complex spinal fractures is feasible and associated with acceptable rates of accuracy and morbidity. [Copyright &y& Elsevier]

Purpose: To evaluate the clinical outcome of patients with surgically refractory trigeminal neuralgia (TN) treated with rescue gamma knife radiosurgery (GKRS). Methods and Materials: Seventy-nine patients with typical TN received salvage GKRS between 1997 and 2002 at the Barrow Neurological Institute (BNI). All patients had recurrent pain following at least one prior surgical intervention. Prior surgical interventions included percutaneous destructive procedures, microvascular decompression (MVD), or GKRS. Thirty-one (39%) had undergone at least two prior procedures. The most common salvage dose was 80 Gy, although 40–50 Gy was typical in patients who had received prior radiosurgery. Pain outcome was assessed using the BNI Pain Intensity Score, and quality of life was assessed using the Brief Pain Inventory. Results: Median follow-up after salvage GKRS was 5.3 years. Actuarial analysis demonstrated that at 5 years, 20% of patients were pain-free and 50% had pain relief. Pain recurred in patients who had an initial response to GKRS at a median of 1.1 years. Twenty-eight (41%) required a subsequent surgical procedure for recurrence. A multivariate Cox proportional hazards model suggested that the strongest predictor of GKRS failure was a history of prior MVD (p=0.029). There were no instances of serious morbidity or mortality. Ten percent of patients developed worsening facial numbness and 8% described their numbness as “very bothersome.” Conclusions: GKRS salvage for refractory TN is well tolerated and results in long-term pain relief in approximately half the patients treated. Clinicians may reconsider using GKRS to salvage patients who have failed prior MVD. [Copyright &y& Elsevier]

The management of children with completely resected intracranial ependymomas is controversial. We favor deferring adjuvant radiotherapy in low-risk patients, whereas others recommend radiotherapy. This article reviews the available evidence for and against deferring radiotherapy in children with low-risk completely resected childhood ependymomas. [ABSTRACT FROM AUTHOR]

Abstract: The case of a 14-year-old boy with behavioral problems and medically refractory epilepsy related to symptomatic gray matter heterotopia in the right frontal lobe is reported. The patient underwent subdural cortical grid placement for seizure localization and functional mapping prior to lesionectomy. On the basis of the patient’s MRI scan, it was predicted that the motor cortex was located adjacent to the abnormality, well anterior to its expected location. This prediction was confirmed by stimulation mapping. The patient underwent successful resection of the lesion under the guidance of the cortical map. Postoperatively, his seizures and behavior improved markedly. This case highlights how eloquent cortex can rarely be drawn toward a region of gray matter heterotopia. In addition, he is one of the few reported cases of focal cortical dysplasia resection with resultant improved behavior. These observations of unusual cortical representations have implications in epilepsy surgery planning. [Copyright &y& Elsevier]

Shows that suspending rhodopsin in trehalose-water glasses allows the trapping of photolysis products. Generation of an intermediate resembling metarhodopsin I and II depending on solubilization conditions; Facile exploration of spectroscopy of the intermediate states; Measurement of the fluorescence resonance energy transfer.

The rich history of neurosurgical innovation served as a model for the Barrow Innovation Center's establishment in 2016. The center's accomplishments are summarized in hopes of fostering the development of similar centers and initiatives within the neurosurgical and broader medical community. A retrospective review (January 2016–July 2021) of patent filings, project proposals, and funding history was used to generate the data presented in this operational review. Through the 5-year period of analysis, 55 prior art searches were conducted on new patentable ideas. A total of 87 provisional patents, 25 Patent Cooperation Treaty applications, and 48 national stage filings were submitted. In partnership with Arizona State University, the University of Arizona, California Polytechnic State University, and Texas A&M University, a total of 27 multidisciplinary projects were conducted with input from multispecialty engineers and scientists. These efforts translated into 1 startup company and 2 licensed patents to commercial companies, with most remaining ideas and project efforts awaiting interest from industry. The multidisciplinary collaborative environment embodied by the Barrow Innovation Center has revolutionized the innovative and entrepreneurial environment of its home institution and enabled neurosurgical residents to get a unique educational experience within the realm of innovation. The bottleneck within the workflow of ideas from conception to commercialization appears to be the establishment of commercial partners; therefore, future efforts within the center will be to establish a panel of industry partnerships to enhance the exposure of ideas to interested companies. [ABSTRACT FROM AUTHOR]

(1) Background: Cushing's disease (CD) is a serious endocrine disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary neuroendocrine tumor (PitNET) that stimulates the adrenal glands to overproduce cortisol. Chronic exposure to excess cortisol has detrimental effects on health, including increased stroke rates, diabetes, obesity, cognitive impairment, anxiety, depression, and death. The first-line treatment for CD is pituitary surgery. Current surgical remission rates reported in only 56% of patients depending on several criteria. The lack of specificity, poor tolerability, and low efficacy of the subsequent second-line medical therapies make CD a medical therapeutic challenge. One major limitation that hinders the development of specific medical therapies is the lack of relevant human model systems that recapitulate the cellular composition of PitNET microenvironment. (2) Methods: human pituitary tumor tissue was harvested during transsphenoidal surgery from CD patients to generate organoids (hPITOs). (3) Results: hPITOs generated from corticotroph, lactotroph, gonadotroph, and somatotroph tumors exhibited morphological diversity among the organoid lines between individual patients and amongst subtypes. The similarity in cell lineages between the organoid line and the patient's tumor was validated by comparing the neuropathology report to the expression pattern of PitNET specific markers, using spectral flow cytometry and exome sequencing. A high-throughput drug screen demonstrated patient-specific drug responses of hPITOs amongst each tumor subtype. Generation of induced pluripotent stem cells (iPSCs) from a CD patient carrying germline mutation CDH23 exhibited dysregulated cell lineage commitment. (4) Conclusions: The human pituitary neuroendocrine tumor organoids represent a novel approach in how we model complex pathologies in CD patients, which will enable effective personalized medicine for these patients. [ABSTRACT FROM AUTHOR]

Background The second part of this study reanalyzes Ponce and Lozano's (2010) list of classics to create a new list of “foundational” articles in neurosurgery. Ponce and Lozano (2010) previously published a list of 106 neurosurgery classics, as defined by Garfield and his 400 citation criterion. Methods We used the Web of Science citation reports to create graphs for each study showing the total citations it received as a function of time. Each graph was subjectively analyzed independently and scored as “foundational” or “classic only,” based on whether the trend of citations received per year was uptrending, neutral, or downtrending. Results Of the 101 evaluated classics, 53 qualified as foundational. Over half of these studies were published in Journal of Neurosurgery (13), New England Journal of Medicine (12), or Lancet (5). Grading systems, randomized trials, and prospective studies were most likely to achieve foundational status. Only 30% of functional and 17% of endovascular classics qualified as foundational (compared with 100% of spine classics), suggesting that these fields are rapidly changing or less mature subspecialties still developing a foundational literature base. Conclusion By assessing citation counts as a function of time, we are able to differentiate classic neurosurgical studies that are critical to modern-day practice from those that are primarily of historic interest. Given the exponential growth of literature in our field, analyses such as these will become increasingly important to both trainees and senior neurosurgeons who strive to educate themselves on the data that drive modern-day clinical decision making. [ABSTRACT FROM AUTHOR]

Objectives  Endoscopic endonasal approaches (EEAs) for petrosectomies are evolving to reduce perioperative brain injuries and complications. Surgical terminology, techniques, landmarks, advantages, and limitations of these approaches remain ill defined. We quantitatively analyzed the anatomical relationships and differences between EEA exposures for medial, inferior, and inferomedial petrosectomies. Design  This study presents anatomical dissection and quantitative analysis. Setting  Cadaveric heads were used for dissection. EEAs were performed using the medial petrosectomy (MP), the inferior petrosectomy (IP), and the inferomedial petrosectomy (IMP) techniques. Participants  Six cadaver heads (12 sides, total) were dissected; each technique was performed on four sides. Main Outcomes and Measures  Outcomes included the area of exposure, visible distances, angles of attack, and bone resection volume. Results  The IMP technique provided a greater area of exposure (p  < 0.01) and bone resection volume (p  < 0.01) when compared with the MP and IP techniques. The IMP technique had a longer working length of the abducens nerve (cranial nerve [CN] VI) than the MP technique (p  < 0.01). The IMP technique demonstrated higher angles of attack to specific neurovascular structures when compared with the MP (midpons [ p  = 0.04], anterior inferior cerebellar artery [ p  < 0.01], proximal part of the cisternal CN VI segment [ p  = 0.02]) and IP (flocculus [ p  = 0.02] and the proximal [ p  = 0.02] and distal parts [ p  = 0.02] of the CN VII/VIII complex) techniques. Conclusion  Each of these approaches offers varying degrees of access to the petroclival region, and the surgical approach should be appropriately tailored to the pathology. Overall, the IMP technique provides greater EEA surgical exposure to vital neurovascular structures than the MP and the IP techniques. [ABSTRACT FROM AUTHOR]

Objective  This study investigated the impact of residual tumor volume (RTV) on tumor progression after subtotal resection and observation of WHO grade I skull base meningiomas. Study Design  This study is a retrospective volumetric analysis. Setting  This study was conducted at a single institution. Participants  Patients who underwent subtotal resection of a WHO grade I skull base meningioma and postsurgical observation (July 1, 2007–July 1, 2017). Main Outcome Measure  The main outcome was radiographic tumor progression. Results  Sixty patients with residual skull base meningiomas were analyzed. The median (interquartile range) RTV was 1.3 (5.3) cm 3. Tumor progression occurred in 23 patients (38.3%) at a mean duration of 28.6 months postsurgery. The 1-, 3-, and 5-year actuarial progression-free survival (PFS) rates were 98.3, 58.6, and 48.7%, respectively. The Cox multivariate analysis identified increasing RTV (p  = 0.01) and history of more than 1 previous surgery (p  = 0.03) as independent predictors of tumor progression. In a Kaplan–Meier analysis for PFS, the RTV threshold of 3 cm 3 maximized log-rank testing significance between groups of patients dichotomized at 0.5 cm 3 thresholds (p  < 0.01). The 3-year actuarial PFS rates for meningiomas with RTV ≤3 cm 3 and >3 cm 3 were 76.2 and 32.1%, respectively. When RTV >3 cm 3 was entered as a covariate in the Cox model, it was the only factor independently associated with tumor progression (p  < 0.01). Conclusion  RTV was associated with tumor progression after subtotal resection of WHO grade I skull base meningioma in this cohort. An RTV threshold of 3 cm 3 was identified that minimized progression of the residual tumor when gross total resection was not safe or feasible. [ABSTRACT FROM AUTHOR]

Objectives  To better understand the risk-benefit profile of skull base meningioma resection in older patients, we compared perioperative complications among older and younger patients. Design  Present study is based on retrospective outcomes comparison. Setting  The study was conducted at a single neurosurgery institute at a quaternary center. Participants  All older (age ≥ 65 years) and younger (<65 years) adult patients treated with World Health Organization grade 1 skull base meningiomas (2008–2017). Main Outcome Measures  Perioperative complications and patient functional status are the primary outcomes of this study. Results  The analysis included 287 patients, 102 older and 185 younger, with a mean (standard deviation [SD]) age of 72 (5) years and 51 (9) years (p  < 0.01). Older patients were more likely to have hypertension (p  < 0.01) and type 2 diabetes mellitus (p  = 0.01) but other patient and tumor factors did not differ (p ≥ 0.14). Postoperative medical complications were not significantly different in older versus younger patients (10.8 [11/102] vs. 4.3% [8/185]; p  = 0.06) nor were postoperative surgical complications (13.7 [14/102] vs. 10.8% [20/185]; p  = 0.46). Following anterior skull base meningioma resection, diabetes insipidus (DI) was more common in older versus younger patients (14 [5/37] vs. 2% [1/64]; p  = 0.01). Among older patients, a decreasing preoperative Karnofsky performance status score independently predicted perioperative complications by logistic regression analysis (p  = 0.02). Permanent neurologic deficits were not significantly different in older versus younger patients (12.7 [13/102] vs. 10.3% [19/185]; p  = 0.52). Conclusion  The overall perioperative complication profile of older and younger patients was similar after skull base meningioma resection. Older patients were more likely to experience DI after anterior skull base meningioma resection. Decreasing functional status in older patients predicted perioperative complications. [ABSTRACT FROM AUTHOR]

Transcranial anterior petrosectomy (AP) is a classic approach; however, it is associated with adverse consequences. The endoscopic endonasal approach (EEA) has been developed as an alternative. We describe surgical techniques for AP and EEA and compare the anatomic exposures of each. Ten cadaveric heads (20 sides) were dissected. Specimens were divided into 4 groups: 1) AP, 2) EEA for medial petrosectomy (MP), 3) EEA for inferior petrosectomy (IP), and 4) EEA for inferomedial petrosectomy (IMP). Outcomes were areas of exposure, angles of attack to neurovascular structures, and bone resection volumes. AP had a greater area of exposure than did MP and IP (P = 0.30, P < 0.01) and had a higher angle of attack to the distal part of the facial nerve–vestibulocochlear nerve (cranial nerve [CN] VII/VIII) complex than did IP and IMP (P < 0.01). MP had a lower angle of attack than IMP to the midpons (P = 0.04) and to the anterior inferior cerebellar artery (P < 0.01). Compared with IMP, IP had a lower angle of attack to the proximal part of the CN VII/VIII complex (P < 0.01) and the flocculus (P < 0.01). The bone resection volume in AP was significantly less than that in MP, IP, and IMP (P < 0.01). AP and all EEA techniques had specific advantages for each specific area. We suggest AP for the ventrolateral pons and the anterior superior internal auditory canal, MP for the midline clivus, IP for the ventrolateral brainstem, and IMP to enhance the lateral corridor of the abducens nerve. [ABSTRACT FROM AUTHOR]

This study evaluates the temporal evolution of the spatial relationship between the pituitary adenoma transsphenoidal surgical cavity and the adjacent optic chiasm and discusses implications on timing and choice of radiotherapy modality. This retrospective observational review analyzed factors that might influence the postoperative relationship between the surgical cavity and the optic chiasm, including tumor type, craniocaudal tumor and resection cavity dimensions, the preoperative distance between tumor and the optic chiasm, the presence of cavernous sinus invasion, and the choice of intraoperative packing material. Changes observed on magnetic resonance imaging in the preoperative, immediate (within 72 h), and delayed (≥3 months) postoperative periods were compared. Sixty-five patient histories were analyzed. Preoperatively, the pituitary adenoma was apposed to the optic chiasm in 43 patients (66%). Postoperatively, 34 patients (52%) in the immediate postoperative period and 54 patients (83%) in the delayed postoperative period had a distance ≥2 mm between the resection cavity and the optic chiasm. This distance provides a greater margin of safety with adjuvant radiosurgery. Preoperative tumor size showed a strong association with postoperative descent of the optic chiasm. Preoperative tumor size and degree of mass effect on the optic chiasm predict postoperative changes. In this study, the distance between the resection cavity and the optic chiasm was greater at ≥3 months postoperatively than in the immediate postoperative period, regardless of preoperative mass effect, indicating radiotherapy planning should be deferred to ≥3 months postoperatively when not precluded by aggressive histological characteristics that necessitate more immediate treatment. To investigate the temporal relationship between the postoperative sellar surgical cavity and the adjacent optic apparatus after transsphenoidal resection of pituitary adenomas and the implications for radiotherapy. • MRIs were evaluated in 65 patients after transsphenoidal pituitary adenoma surgery. • A subset of these patients may require adjuvant radiotherapy. • Radiosurgery is safest when the optic chiasm is >2 mm from the resection cavity. • The surgical cavity involutes predictably, increasing distance from the optic chiasm over time. [ABSTRACT FROM AUTHOR]

Objectives Skull base endoscopy allows for minimal access approaches to the sinonasal contents and cranial base. Advances in endoscopic technique and applications have been published rapidly in recent decades. Setting We utilized an Internet-based scholarly database (Web of Science, Thomson Reuters) to query broad-based phrases regarding skull base endoscopy literature. Participants All skull base endoscopy publications. Main Outcome Measures Standard bibliometrics outcomes. Results We identified 4,082 relevant skull base endoscopy English-language articles published between 1973 and 2014. The 50 top-cited publications (n = 51, due to articles with equal citation counts) ranged in citation count from 397 to 88. Most of the articles were clinical case series or technique descriptions. Most (96% [49/51]) were published in journals specific to either neurosurgery or otolaryngology. Conclusions A relatively small number of institutions and individuals have published a large amount of the literature. Most of the publications consisted of case series and technical advances, with a lack of randomized trials. [ABSTRACT FROM AUTHOR]

Objective  The carotico-clinoid foramen and interclinoid bridge are two anatomical variants of the sellar region. If these anatomical variants go unrecognized and are not managed safely by the surgeon during expanded endoscopic endonasal surgery for a posterior clinoidectomy, a carotid artery injury may occur. We summarize a method to safely navigate in the presence of the carotico-clinoid foramen and interclinoid bridge in an endoscopic endonasal approach. Study Design  The study involves cadaveric dissection and management of the anatomical variants. Setting  The study took place in a cadaveric dissection laboratory. Participants  The object of study is one cadaveric head. Main Outcome Measures  After discovering the two variants in both cavernous sinuses of a cadaveric head, we established a stepwise coping strategy to avoid carotid artery injury while performing an endoscopic endonasal bilateral interdural pituitary transposition, and we report the final view after endoscopic management. Results  Debulking of the middle clinoid process can decrease the obstacle effect, and the pituitary transposition can be performed medial to the ossified carotico-clinoid ligament. Disconnection of the interclinoid bridge is the prerequisite to an effective posterior clinoidectomy, and distinguishing the transition between the sellar diaphragm and the interclinoid bridge is essential. Conclusion  In the presence of both the carotico-clinoid foramen and the interclinoid bridge, a bilateral interdural pituitary transposition can still be performed, although preoperative strategic preparation, full inspection, and stepwise disconnections are of paramount importance in such a scenario to avoid cavernous carotid artery injury. [ABSTRACT FROM AUTHOR]

Granular cell tumors (GCTs), pituicytomas, and spindle cell oncocytomas are rare, nonfunctioning pituitary tumors sharing positive staining of thyroid transcription factor 1. We present our series, the first single-institutional report with long-term surgical follow-up of all 3 tumor types. Our institutional pathology database was queried for these 3 pathologic diagnoses. Clinical records were assessed for clinical presentation, preoperative and postoperative endocrine status, tumor location on imaging, surgical characteristics, pathology results, and tumor recurrence. Data were analyzed for 4 patients with GCTs, 4 with pituicytomas, and 3 with spindle cell oncocytomas. The most common symptoms at presentation were vision changes (64%), headache (55%), endocrine abnormalities (55%), and fatigue (46%). GCTs were the only subtype to present exclusively in the infundibulum and the only subtype in our series to be treated with a transcranial transsylvian approach to resection (n = 2). In our study, in contrast to other reports, estimated blood loss was less than 300 mL in all patients. Imaging confirmed gross total resection in all 11 cases with no known recurrences at a mean (standard deviation) follow-up of 4.7 (3.7) years. We present a single-institution series of rare thyroid transcription factor 1–staining posterior pituitary tumors of the sellar region. Key novel findings include gross total resection with no tumor recurrence at nearly 5 years of mean follow-up and no cases of excess or uncontrolled blood loss. Our findings reinforce the observation that GCTs present in the suprasellar space. [ABSTRACT FROM AUTHOR]

Objective Patients with hydrocephalus secondary to third ventricular colloid cysts can require bilateral external ventricular drain (EVD) placement while awaiting surgery. However, some patients could develop auto-fenestration of the septum pellucidum (AFSP) and only require 1 EVD. We evaluated our experience with bedside iohexol ventriculography and staged EVD placement for patients with obstructive hydrocephalus. Methods We retrospectively identified 34 patients who had been treated for third ventricular colloid cysts (2013–2016). The preoperative and postoperative data, including age, sex, colloid cyst size, preoperative hydrocephalus, preoperative EVD placement, preoperative iohexol ventriculography, operative approach, intraoperative findings, and postoperative ventriculoperitoneal shunt requirements, were reviewed. Results Hydrocephalus was found in 23 patients (68%) on initial presentation. Nine patients (26%) had EVDs placed before surgery. Six patients (18%) underwent iohexol ventriculography after insertion of a right-sided EVD. Five patients (15%) demonstrated no evidence of ventricular communication. Four patients (67%) required left-sided EVD placement. One patient (17%) had robust communication between the lateral ventricles after intraventricular iohexol injection, which was managed with a single EVD. AFSP was observed during surgical resection of this patient's colloid cyst. One other patient who did not undergo preoperative EVD placement was noted to have AFSP intraoperatively, resulting in 2 of 34 patients (6%) with AFSP in our series. Conclusions A subset of patients with obstruction at the foramina of Monro can develop AFSP. Iohexol ventriculography after unilateral EVD placement allows clinicians to assess for the presence of AFSP and identify patients who can be treated with a single EVD before surgery. [ABSTRACT FROM AUTHOR]

Objective Visual field (VF) outcomes are commonly reported in neurosurgical case series; however, substantial variability can exist in VF testing and outcome reporting. We aimed to evaluate the challenges of VF testing and to develop detailed recommendations for VF outcome reporting by analyzing results from an ongoing, multicenter study of transsphenoidal pituitary surgery. Methods VF testing results were collected during a prospective, multicenter clinical trial evaluating patient outcomes after transsphenoidal surgery for nonfunctioning pituitary adenomas (TRANSSPHER). Two independent ophthalmologists reviewed reliability and outcomes of all VF studies. Preoperative and postoperative VF studies were evaluated individually and as preoperative/postoperative pairs. Results Suboptimal perimetry field settings were reported in 37% of VF studies. Automated reliability criteria flagged 25%–29% of VF studies as unreliable, whereas evaluation by 2 independent ophthalmologists flagged 16%–28%. Agreement between automated criteria and raters for VF reliability was inconsistent (κ coefficients = 0.55–0.83), whereas agreement between the 2 raters was substantial to almost perfect (κ coefficients = 0.78–0.83). Most patients demonstrated improvement after surgery (rater 1, 67%; rater 2, 60%), with substantial rater agreement on outcomes for paired examinations (κ coefficient = 0.62). Conclusions VF outcome studies demonstrated significant variability of test parameters and patient performance. Perimetry field settings varied among patients and for some patients varied preoperatively versus postoperatively. Reliance on automated criteria alone could not substitute for independent ophthalmologist review of test reliability. Standardized guidelines for VF data collection and reporting could increase reliability of results and allow better comparisons of outcomes in future studies. Highlights • In a multicenter trial, 30% of VF studies were unreliable. • Neurosurgeons and researchers should consider the potential unreliability of VF data. • We review sources of unreliable VF testing in a transsphenoidal surgery cohort. • We propose guidelines to improve VF reporting in future neurosurgical studies. [ABSTRACT FROM AUTHOR]

Objective To describe an endoscopic anterolateral surgical route to the lateral portion of Meckel's cave. Methods A sublabial transmaxillary transpterygoid approach was performed in 6 cadaveric heads (12 sides). A craniectomy was drilled between the foramen rotundum (FR) and foramen ovale (FO) with defined borders. Extradural dissection was performed up to the V2–V3 junction of the trigeminal ganglion. The working space was analyzed using anatomic measurements. Results The approach allowed for extradural dissection to the lateral aspect of Meckel's cave and provided excellent exposure of V2, V3, and the V2–V3 junction at the gasserian ganglion. The mean distance between the FR and FO along the pterygoid process of the sphenoid bone was 21.3 ± 2.8 mm (range, 18–24.4 mm). The mean distance of V2 and V3 segments from their foramina to the gasserian ganglion junction was 12.0 ± 2.3 mm (range, 9.2–14.6 mm) and 15.2 ± 2.7 mm (range, 12.3–18.5 mm), respectively (6 sides). A potential working area (mean area, 89 mm 2 ) is described. Its superior edge is from the FR to the V2–V3 junction at the gasserian ganglion, its inferior edge is from the FO to the V2–V3 junction at the gasserian ganglion, and its base is from the FO to the FR. The surgical anatomy of the infratemporal fossa, pterygopalatine fossa, and lateral Meckel's cave is highlighted. Conclusions An endoscopic anterolateral sublabial transmaxillary transpterygoid approach between the FR and FO avoids crossing critical neurovascular structures within the cavernous sinus and pterygopalatine fossa and can provide a safe surgical corridor for laterally based lesions in Meckel's cave. [ABSTRACT FROM AUTHOR]

Chordoma is a rare, radiation-resistant, skull-base and spinal tumor with high local recurrence containing mixed cell-adhesion phenotypes. We characterized DNA damage response (DDR) signaling (γH2AX, pKAP1, pATM) and survival response to ionizing radiation (IR) in human chordoma samples (42 resections, 23 patients) to test if blocking cell adhesion sensitizes U-CH1 tumor cells to IR. U-CH1 cells expressed brachyury, YAP, and laminin adhesion receptors (CD49c, CD49f, CD44), and approximately 15% to 20% of U-CH1 cells featured an α6 integrindependent (CD49f) cohesive cluster phenotype, which confers therapeutic resistance and aids metastasis. DDR to IR in U-CH1 cells was compared to normal prostate epithelial (PrEC) and tumor cells (DU145). Flow cytometry showed a dose- and time-dependent increase in γH2AX and pKAP1 expression in all cell lines. However, nearly 50% of U-CH1 cells exhibited nonresponsive phenotype to IR (measured by γH2AX and pKAP1) independent of cell cycle status. Immunofluorescence microscopy verified that only 15% of U-CH1 clustered cells were γH2AX or pKAP1 positive (versus 80% of nonclustered cells) 2 hours following 2-Gy IR. Conversely, both tumor cell lines were uniformly defective in pATM response. HYD1, a synthetic ECM ligand, inhibited DDR through an unresolved γH2AX response. β1 integrin-blocking antibody (AIIB2) decreased cell survival 50% itself and approximately doubled the IR-induced cell kill at all IR doses observed at 2 and 4 weeks posttreatment. These results suggest that a heterogeneity of DDR to IR exists within a chordoma population. Blocking integrin function alone and/or as an adjuvant to IR may eradicate chordomas containing the cohesive cluster phenotype. [ABSTRACT FROM AUTHOR]

Objectives The Hardy classification is used to classify pituitary tumors for clinical and research purposes. The scale was developed using lateral skull radiographs and encephalograms, and its reliability has not been evaluated in the magnetic resonance imaging (MRI) era. Design Fifty preoperative MRI scans of biopsy-proven pituitary adenomas using the sellar invasion and suprasellar extension components of the Hardy scale were reviewed. Setting This study was a cohort study set at a single institution. Participants There were six independent raters. Main Outcome Measures The main outcome measures of this study were interrater reliability, intrarater reliability, and percent agreement. Results Overall interrater reliability of both Hardy subscales on MRI was strong. However, reliability of the intermediate scores was weak, and percent agreement among raters was poor (12-16%) using the full scales. Dichotomizing the scale into clinically useful groups maintained strong interrater reliability for the sellar invasion scale and increased the percent agreement for both scales. Conclusion This study raises important questions about the reliability of the original Hardy classification. Editing the measure to a clinically relevant dichotomous scale simplifies the rating process andmay be useful for preoperative tumor characterization in the MRI era. Future research studies should use the dichotomized Hardy scale (sellar invasion Grades 0-III versus Grade IV, suprasellar extension Types 0-C versus Type D). [ABSTRACT FROM AUTHOR]

Objective The endoscopic supracerebellar-infratentorial (SCIT) approach is a viable method to access pathology of the posterior incisura, but a narrow working space and frequent instrument conflict can potentially limit its surgical efficacy. Until now, no rigorous studies were available comparing surgical freedom and angle of attack for four previously well-described approaches to pineal region targets. Methods Four formalin-fixed cadaver heads were dissected bilaterally (eight sides). A midline approach and three progressively lateral approaches to the pineal region were performed (paramedian, lateral, extreme lateral), and anatomical targets were identified. Utilizing frameless stereotaxy, we calculated surgical freedom using the vector cross-product method for all approaches for the exposed area and for three anatomical targets (pineal gland, ipsilateral superior colliculus, splenium). The mean and maximum possible angles of attack were calculated in the axial and sagittal planes. Results Point target surgical freedom, exposed area surgical freedom, and angle of attack for each individual pineal region target can be maximized depending on the medial-to-lateral location of the craniotomy. For endoscopic-controlled approaches, the extreme lateral approach provides the largest surgical freedom when accessing the ipsilateral superior colliculus ( P < 0.0001), the lateral approach provides the largest surgical freedom to the pineal gland ( P < 0.0001), and the paramedian craniotomy provides the largest surgical freedom when accessing the splenium ( P < 0.0001). The extreme lateral approach to the pineal gland provided the largest horizontal angle of attack ( P < 0.0001), and the extreme lateral approach to the ipsilateral superior colliculus provided the largest vertical angle of attack ( P < 0.001). The microscope provides marginally increased surgical freedom and a better angle of attack to specific anatomical targets in the paramedian and extreme lateral approach compared with those provided by the endoscope, but these differences are negligible during intraoperative application. Conclusions Presurgical planning and a detailed understanding of the important neurovascular structures in the pineal region are paramount to safe and successful surgical execution. Our current cadaveric study indicates that the medial-to-lateral location of craniotomy can maximize access to pineal region targets. Furthermore, the endoscope is a viable alternative to the microscope for identifying pathology of the posterior incisura. These differences in surgical freedom and angle of attack to the pineal region may be useful to consider when planning minimal-access approaches. [ABSTRACT FROM AUTHOR]

Objective Endoscopic ipsilateral endonasal transmaxillary, contralateral endonasal transseptal transmaxillary, and Caldwell-Luc approaches can access lesions within the retromaxillary space and pterygopalatine fossa. We compared the exposure and surgical freedom of these transmaxillary approaches to assist with surgical decision making. Design Four cadaveric heads were dissected bilaterally using the three approaches just described. Prior to dissection, stereotactic computed tomography (CT) scans were obtained on each head to obtain anatomical measurements. Surgical freedom and area of exposure were determined by stereotaxis. Main Outcome Measures Area of exposure was calculated as the extent of the orbital floor, maxillary sinus floor, nasal floor, and mandibular ramus exposed through each approach. Surgical freedom was the area through which the proximal end of the endoscope could be freely moved while moving the tip of the endoscope to the edges of the exposed area. Results The mean exposed area was similar: 9.9 ± 2.5 cm² (Caldwell-Luc), 10.4 ± 2.6 cm² (ipsilateral endonasal), and 10.1 ± 2.1 cm² (contralateral transseptal) (p > 0.05). The surgical freedom of the Caldwell-Luc approach (113 ± 7 cm²) was greater than for either endonasal approach, 76 cm² ± 15 (p = 0.001) (ipsilateral endonasal) and 83 cm² ± 15 (p = 0.003) contralateral transseptal. Conclusions Our work demonstrates that the Caldwell-Luc endonasal approach offers greater surgical freedom than either approach for anterolateral skull base targets, although these approaches offer similar exposure. [ABSTRACT FROM AUTHOR]

Objective Surgical freedom and the angle of attack influence approach selection for open cranial base approaches, but these concepts have not been well studied in minimal-access endoscopic approaches. We therefore developed a methodology to study surgical freedom and angle of attack in two endoscopic transmaxillary transpterygoid approaches, the endonasal ipsilateral uninostril medial maxillotomy and the sublabial Caldwell-Luc anterior maxillotomy. Methods Dissections were performed bilaterally in three formalin-fixed cadaver heads (six sides). For each approach, three progressively lateral and posterior anatomic targets were identified. Utilizing frameless stereotaxy, surgical freedom using the vector cross-product method was calculated for both approaches for each target. The mean and maximum possible angles of attack were calculated in the axial and sagittal planes. Results Compared to the endoscopic endonasal-transmaxillary approach, the endoscopic Caldwell-Luc approach offered significantly greater surgical freedom to the genu of the internal carotid artery ( P = 0.02), foramen rotundum ( P = 0.03), and foramen ovale ( P = 0.03). Mean and maximum possible angles of attack were also significantly different between the two approaches for each target. The Caldwell-Luc approach offered a more bottom-up approach in the sagittal plane and a more head-on approach in the axial plane to each target ( P < 0.05). Conclusions We have successfully developed a model for comparing endoscopic skull base approaches. Both the endonasal medial maxillotomy approach and Caldwell-Luc approach provided endoscopic access to each target. However, the sublabial Caldwell-Luc approach offered greater surgical freedom and a more head-on approach than the endonasal medial maxillotomy. These differences in surgical freedom and angles of attack may be useful to consider when planning minimal-access approaches. [ABSTRACT FROM AUTHOR]