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Objective: Identify the benefits and caveats of combining minimal access approaches to the infratemporal fossa (ITF), such as the endoscopic transnasal, endoscopic transorbital, endoscopic transoral, and endoscopic sublabial transmaxillary approaches to address extensive lesions not amenable to a single approach. The study provides anatomical metrics including area of exposure and degree of surgical freedom. Methods: Five human cadaveric specimens (10 sides) were dissected to expose and methodically analyze the anatomical intricacies of the ITF using the following minimal access approaches: endoscopic transnasal transpterygoid (EETA), endoscopic sublabial transmaxillary, endoscopic transorbital via infraorbital foramen, and endoscopic transoral techniques. Area of exposure at the pterygopalatine fossa and surgical freedom at the ITF were obtained for each approach. Results: The endoscopic sublabial transmaxillary sinus and the combined approach afford a significantly greater exposure than an isolated EETA. The difference in exposure (mean) between the endoscopic sublabial transmaxillary and EETA was 1.62 ± 0.85 cm2 (p < 0.001), and the difference between the combined approach and EETA was 4.25 ± 0.85 cm2 (p < 0.001). Conclusions: Combining minimal access endoscopic approaches to the ITF can provide significantly greater exposure than an isolated EETA; thus, providing enhanced access to address lesions with extensive involvement of the ITF, especially those with superolateral and inferolateral extensions. In addition, some approaches may have an adjunctive role to the resection, such as the endoscopic transoral approach offering the potential for early control of the internal maxillary artery and its branches, some of which may be supplying the tumor in the ITF; or the endoscopic transorbital approach yielding a direct line of sight to the superior ITF and middle cranial fossa. Level of Evidence: NA. [ABSTRACT FROM AUTHOR]

Background: Chronic subdural hematoma (SDH) is a common condition encountered in neurosurgical practice; however, its pathogenesis remains controversial. Current Concepts: SDH refers to blood accumulation inside the dura and is classified into acute, subacute, and chronic types. Histopathologically, acute SDH shows no neomembrane formation and the hematoma is a clot, in contrast to chronic SDH characterized by a neomembrane surrounding the liquefied hematoma. SDH is usually categorized into acute and chronic types, with subacute SDH being more similar to chronic SDH. Posttraumatic subdural lesions include acute and chronic SDH, subdural hygroma (SDG), or effusion. SDG is a blood-tinged fluid accompanied by neomembrane formation in some cases. These lesions are pathologically different from each other but may change depending on the situation. Discussion and Conclusion: Chronic SDH mainly originates from an SDG and acute SDH. SDG is usually triggered by trauma but only occurs in patients in whom sufficient potential space is available and may occur spontaneously in such cases. Therefore, SDG frequently occurs in children and in elderly patients, in men with a larger skull size, and on the left side of the body, which usually shows a wider hemisphere. Separation of the dural border cell layer causes inflammation, indicated by fibroblast proliferation and neovascularization. Conversion of an SDG into a chronic SDH or enlargement of a chronic SDH is attributable to formation of neomembranes, neovascularization, and repeated microhemorrhages from fragile capillaries. Chronic SDH is treated with removal of the hematoma to relieve the mass effect and embolization of the feeding artery for the bleeder. Outcomes of chronic SDH depend on the absorptive-expansion capacity dynamics. [ABSTRACT FROM AUTHOR]

Purpose: To describe the characteristics, management, and outcomes of pediatric patients with sporadic vestibular schwannoma (sVS). Methods: This was a case series at a tertiary care center. Patients were identified through a research repository and chart review. Interventions were microsurgery, stereotactic radiosurgery (SRS), and observation. Outcome measures were tumor control, facial nerve function, and hearing. Results: Eight patients over 2006–2022 fulfilled inclusion criteria (unilateral VS without genetic or clinical evidence of neurofibromatosis type 2 (NF2); age ≤ 21) with a mean age of 17 years (14–20). Average greatest tumor length in the internal auditory canal was 9.7 mm (4.0–16.1). Average greatest tumor dimension (4/8 tumors) in the cerebellopontine angle was 19.1 mm (11.3–26.8). Primary treatment was microsurgery in five (62.5%) patients, observation in two (25%), and SRS in one (12.5%). Four (80%) surgical patients had gross total resections, and one (20%) had regrowth post-near total resection and underwent SRS. One observed patient and the primary SRS patient have remained radiographically stable for 3.5 and 7 years, respectively. The other observed patient required surgery for tumor growth after 12 months of observation. Two surgical patients had poor facial nerve outcomes. All post-procedural patients developed anacusis. Mean follow-up was 3 years (0.5–7). Conclusions: We describe one of the largest reported cohorts of pediatric sVS in the USA. Diligent exclusion of NF2 is critical. Given the high likelihood of eventually requiring intervention and known adverse effects of SRS, microsurgery remains the preferred treatment. However, observation can be considered in select situations. [ABSTRACT FROM AUTHOR]

Background: Despite endovascular coiling as a valid modality in treatment of aneurysmal subarachnoid hemorrhage (aSAH), there is a risk of poor prognosis. However, the clinical utility of previously proposed early prediction tools remains limited. We aimed to develop a clinically generalizable machine learning (ML) models for accurately predicting unfavorable outcomes in aSAH patients after endovascular coiling. Methods: Functional outcomes at 6 months after endovascular coiling were assessed via the modified Rankin Scale (mRS) and unfavorable outcomes were defined as mRS 3-6. Five ML algorithms (logistic regression, random forest, support vector machine, deep neural network, and extreme gradient boosting) were used for model development. The area under precision-recall curve (AUPRC) and receiver operating characteristic curve (AUROC) was used as main indices of model evaluation. SHapley Additive exPlanations (SHAP) method was applied to interpret the best-performing ML model. Results: A total of 371 patients were eventually included into this study, and 85.4% of them had favorable outcomes. Among the five models, the DNN model had a better performance with AUPRC of 0.645 (AUROC of 0.905). Postoperative GCS score, size of aneurysm, and age were the top three powerful predictors. The further analysis of five random cases presented the good interpretability of the DNN model. Conclusion: Interpretable clinical prediction models based on different ML algorithms have been successfully constructed and validated, which would serve as reliable tools in optimizing the treatment decision-making of aSAH. Our DNN model had better performance to predict the unfavorable outcomes at 6 months in aSAH patients compared with Yan's nomogram model. [ABSTRACT FROM AUTHOR]

It is difficult to predict the surgical effect and outcome of severe traumatic brain injury (TBI) before surgery. This study aims to approve an evaluation method of computed tomography angiography (CTA) to predict the effect of surgery and outcome in severe TBI. Between January 2010 and January 2020, we retrospectively reviewed 358 severe TBI patients who underwent CTA at admission and reexamination. CTA data were evaluated for the presence of cerebrovascular changes, including cerebrovascular shift (CS), cerebral vasospasm (CVS), large artery occlusion (LAO), and deep venous system occlusion (DVSO). Medical records were reviewed for baseline clinical characteristics and the relationship between CTA changes and outcomes. Cerebrovascular changes were identified in 247 (69.0%) of 358 severe TBI patients; only 25 (10.12%) of them had poor outcomes, and 162 (65.6%) patients had a good recovery. Eighty-three (23.18%) patients were diagnosed with CVS, 10 (12.05%) had a good outcome, 57 (68.67%) had severe disability and 16 (19.28%) had a poor outcome. There were twenty-six (7.3%) patients who had LAO and thirty-one (8.7%) patients who had DVSO; no patients had good recovery regardless of whether they had the operation or not. Cerebrovascular injuries and changes are frequent after severe TBI and correlate closely with prognosis. CTA is an important tool in evaluating the severity, predicting the operation effect and prognosis, and guiding therapy for severe TBI. Well-designed, multicenter, randomized controlled trials are needed to evaluate the value of CTA for severe TBI in the future. [ABSTRACT FROM AUTHOR]

Background: Anterior endoscopic access to middle cranial base lesions becomes feasible in the presence of infratemporal fossa (ITF) involvement. Various approaches, including endoscopic endonasal, transoral sublabial, and transorbital methods, have been described for accessing the ITF through a transmaxillary corridor. Among these approaches, endonasal access is the most commonly preferred, while the transorbital approach is a novel technique gaining popularity. The transoral sublabial approach is considered suitable for selected lesions., Methods: Patients who underwent the anterior endoscopic transoral/sublabial transmaxillary approach to middle cranial base lesions at a single institute from 2016 to 2023 were included in this retrospective study. Malignant lesions were excluded from the study. The sublabial approach was exclusively performed in all cases, with the exception of one patient who required a combined approach., Results: The anterior endoscopic transoral sublabial transmaxillary approach to the infratemporal fossa, upper parapharyngeal space, and middle cranial fossa was performed on 14 patients. The underlying conditions for these patients were as follows: trigeminal schwannomas (n = 8), meningiomas (n = 2), juvenile nasopharyngeal angiofibroma, osteochondroma, arachnoid cyst and encephalocele (n = 1 each). Gross total resection was achieved in 11 cases. The most common complication was numbness in the territory of the maxillary and mandibular nerves (n = 4). Two patients needed endoscopic maxillary antrostomy for persistent suppuration. No wound problems or CSF rhinorrhea occurred. The average follow-up time was 26.6 months., Conclusion: The endoscopic sublabial transmaxillary approach provides direct access to the infratemporal fossa and middle cranial base, enhancing the surgical range of maneuverability while sparing the sinonasal cavity. This procedure is safe, less invasive, and could be used as an efficient corridor for the resection of selected infratemporal fossa lesions with or without extension to the middle cranial base and parapharyngeal space., (© 2024 Wiley Periodicals LLC.)

The incidence of posterior inferior cerebellar artery (PICA) aneurysms is estimated to be between 0.5% and 3% of total aneurysm cases.1 Most patients with these aneurysms typically present with subarachnoid hemorrhage, although there are instances in which patients may present with symptoms resulting from mass effect exerted on the brain stem or lower cranial nerves.1,2 Treatment options for PICA aneurysms include endovascular procedures, surgical clipping, or bypass techniques.2 Surgical treatment is considered more effective for partially thrombosed aneurysms compared with endovascular approaches.3 In addition, endovascular coiling of these aneurysms carries the potential risk of coil migration and subsequent reopening of the aneurysm lumen.4 In certain instances, thrombosed PICA aneurysms have the potential to simulate the radiological characteristics of alternative pathologies, such as cavernous malformations or brainstem tumors.5-7 This situation can result in misdiagnosis and inappropriate management. We present the case of a patient who exhibited symptoms of imbalance and dysfunction in the lower cranial nerves. Magnetic resonance imaging findings indicated a possible cavernous malformation in the medulla oblongata. However, further investigation revealed that the underlying cause was a thrombosed PICA aneurysm. The patient was successfully treated through surgical clipping. The patient consented to the procedure and to the publication of his/her image., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Malignant transformation of vestibular schwannoma (VS) post-radiosurgery is an extremely rare but life-threatening complication. We present a patient who underwent two surgeries for a benign VS and received Gamma Knife radiosurgery for residual tumour. Five and a half years post-radiosurgery, the patient was reoperated for symptomatic recurrence of the tumour. Histopathology confirmed the diagnosis of a high-grade spindle cell sarcoma. Although near-total resection was uneventful, the patient deteriorated rapidly, and comfort care was chosen. This report is the 13th documented case of histopathologically confirmed malignant transformation of a benign VS that strictly meets the modified Cahan's criteria, suggesting the direct link to radiosurgery-induced malignancy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)