Surgical management of symptomatic hemangioma of the geniculate ganglion: fascicular-sparing resection or grafting?

Geniculate ganglion hemangioma (GGH) is rarely presented in the neurosurgical literature. It extends extradurally on the middle fossa floor and displaces the intratemporal part of the facial nerve. Surgical treatment is advisable at early symptoms. Proposed techniques include fascicular-sparing resection or nerve interruption with grafting. No definitive conclusions exist about the superiority of a certain technique in preserving facial nerve integrity and function. Through the description of a surgically managed symptomatic GGH, we herein discuss literature data about the surgical results of fascicular-sparing resection versus grafting. A PRISMA-based literature search was performed on the PubMed database. Only articles in English and published since 1990 were selected and furtherly filtered based on the best relevance. Statistical comparisons were performed with ANOVA. One hundred sixteen GGHs were collected, 56 were treated by fascicular-sparing resection, and 60 were treated by grafting. The facial function was improved, or unchanged, in 53 patients of the fascicular-sparing group and 30 patients of the grafting one. Sixty-five patients achieved a good (House-Brackmann (HB) grade III) postoperative facial outcome, of which 47 and 18 belonged to the fascicular-sparing and grafting group, respectively. Greater efficacy of the fascicular-sparing technique in the achievement of a better facial outcome was found (p = 0.0014; p = 0.0022). A surgical resection at the earliest symptoms is critical to preserve the facial nerve function in GGHs. Fascicular-sparing resection should be pursued in symptomatic cases with residual facial function (I-III HB). Conversely, grafting has a rationale for higher HB grades (V-VI). Broader studies are required to confirm these findings and turn them into new therapeutic perspectives.

Novel "T-Dimension" Therapies for Pediatric Optic Pathway Glioma: A Timely, Targeted, and Tailored Treatment Trend.

INTRODUCTION: Novel targeted and tailored therapies can substantially improve the prognosis for optic pathway glioma (OPG), especially when implemented in a timely manner. However, their tremendous potential remains underestimated. Therefore, in this study, we provide an updated overview of the clinical trials, current trends, and future perspectives for OPG's novel therapeutic strategies. METHODS: We completed an extensive literature review using the PubMed, MEDLINE, and ClinicalTrials.gov databases. We analyzed and reported the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Thioguanine, procarbazine, lomustine, and vincristine/vinblastine, as well as cisplatin-etoposide, provided excellent results in advanced-phase trials. Selumetinib and trametinib, two oral MEK inhibitors, have been approved for recurrent or refractory OPGs in association with the angiogenetic inhibitor bevacizumab. Among the mTOR inhibitors, everolimus and sirolimus showed the best results. Stereotactic radiosurgery and proton beam radiation therapy have advantages over conventional radiotherapy regimens. Timely treatment is imperative for acute visual symptoms with evidence of tumor progression. This latest evidence can help define a novel "T-Dimension" for pediatric OPG therapies. CONCLUSION: The novel "T-Dimension" for pediatric OPGs is based on recent evidence-based treatments, including combination chemotherapy regimens, molecular targeted therapies, stereotactic radiosurgery, and proton beam radiation therapy. Additional clinical trials are essential for validating each of these new therapies.

Rating the incidence of iatrogenic vascular injuries in thoracic and lumbar spine surgery as regards the approach: A PRISMA-based literature review.

PURPOSE: To assess the rate, timing of diagnosis, and repairing strategies of vascular injuries in thoracic and lumbar spine surgery as their relationship to the approach. METHODS: PubMed, Medline, and Embase databases were utilized for a comprehensive literature search based on keywords and mesh terms to find articles reporting iatrogenic vascular injury during thoracic and lumbar spine surgery. English articles published in the last ten years were selected. The search was refined based on best match and relevance. RESULTS: Fifty-six articles were eligible, for a cumulative volume of 261 lesions. Vascular injuries occurred in 82% of instrumented procedures and in 59% during anterior approaches. The common iliac vein (CIV) was the most involved vessel, injured in 49% of anterior lumbar approaches. Common iliac artery, CIV, and aorta were affected in 40%, 28%, and 28% of posterior approaches, respectively. Segmental arteries were injured in 68% of lateral approaches. Direct vessel laceration occurred in 81% of cases and recognized intraoperatively in 39% of cases. CONCLUSIONS: Incidence of iatrogenic vascular injuries during thoracic and lumbar spine surgery is low but associated with an overall mortality rate up to 65%, of which less than 1% for anterior approaches and more than 50% for posterior ones. Anterior approaches for instrumented procedures are at risk of direct avulsion of CIV. Posterior instrumented fusions are at risk for injuries of iliac vessels and aorta. Lateral routes are frequently associated with lesions of segmental vessels. Suture repair and endovascular techniques are useful in the management of these severe complications.

Supratentorial high-grade gliomas: maximal safe anatomical resection guided by augmented reality high-definition fiber tractography and fluorescein.

OBJECTIVE: The theoretical advantages of augmented reality (AR) with diffusion tensor imaging (DTI)-based high-definition fiber tractography (HDFT) and sodium fluorescein (F) in high-grade glioma (HGG) surgery have not been investigated in detail. In this study, the authors aimed to evaluate the safety and efficacy profiles of HDFT-F microscope-based AR cytoreductive surgery for newly diagnosed supratentorial HGGs. METHODS: Data of patients with newly diagnosed supratentorial HGGs who underwent surgery using the AR HDFT-F technique were reviewed and compared with those of a cohort of patients who underwent conventional white-light surgery assisted by infrared neuronavigation. The safety and efficacy of the techniques were reported based on the postoperative Neurological Assessment in Neuro-Oncology (NANO) scores, extent of resection (EOR), and Kaplan-Meier curves, respectively. The chi-square test was conducted for categorical variables. A p value < 0.05 was considered statistically significant. RESULTS: A total of 54 patients underwent surgery using the AR HDFT-F technique, and 63 underwent conventional white-light surgery assisted by infrared neuronavigation. The mean postoperative NANO scores were 3.8 ± 2 and 5.2 ± 4 in the AR HDFT-F group and control group, respectively (p < 0.05). The EOR was higher in the AR HDFT-F group (p < 0.05) than in the control group. With a mean follow-up of 12.2 months, the rate of progression-free survival (PFS) was longer in the study group (log-rank test, p = 0.006) than in the control group. Moreover, the complication rates were 9.2% and 9.5% in the study and control groups, respectively. CONCLUSIONS: Overall, AR HDFT-F-assisted surgery is safe and effective in maximizing the EOR and PFS rate for patients with newly diagnosed supratentorial HGGs, and in optimizing patient functional outcomes.

Shedding the Light on the Natural History of Intracranial Aneurysms: An Updated Overview.

The exact molecular pathways underlying the multifactorial natural history of intracranial aneurysms (IAs) are still largely unknown, to the point that their understanding represents an imperative challenge in neurovascular research. Wall shear stress (WSS) promotes the genesis of IAs through an endothelial dysfunction causing an inflammatory cascade, vessel remodeling, phenotypic switching of the smooth muscle cells, and myointimal hyperplasia. Aneurysm growth is supported by endothelial oxidative stress and inflammatory mediators, whereas low and high WSS determine the rupture in sidewall and endwall IAs, respectively. Angioarchitecture, age older than 60 years, female gender, hypertension, cigarette smoking, alcohol abuse, and hypercholesterolemia also contribute to growth and rupture. The improvements of aneurysm wall imaging techniques and the implementation of target therapies targeted against inflammatory cascade may contribute to significantly modify the natural history of IAs. This narrative review strives to summarize the recent advances in the comprehension of the mechanisms underlying the genesis, growth, and rupture of IAs.

Microsurgical Clipping of Carotid-Ophthalmic Tandem Aneurysms: Case Report and Surgical Nuances.

Tandem intracranial aneurysms (TandIAs) are rare but inherently complex, and special technical considerations are required for their surgical management. The present case highlights the key surgical aspects of two carotid-ophthalmic TandIAs incidentally found in a 60-year-old female. Both the aneurysms were superiorly projecting, regular in size, and involved the left ophthalmic segment of the internal carotid artery (ICA). The minimum distance between the necks was 3 mm. The patient underwent microsurgery because of the reported major complications rate of the endovascular treatment in the case of a very short minimum distance between the TandIAs. After cervical ICA exposure, both the aneurysms were excluded through a pterional approach. Intradural anterior clinoidectomy and unroofing of the optic canal allowed the mobilization of the left optic nerve. The more distal aneurysm was clipped before the opening of the distal dural ring of the ICA. The proximal aneurysm was clipped with two straight clips stacked perpendicular to the ICA. A small remnant was intentionally left to avoid the stenosis of the ophthalmic artery. Postoperative angiography showed the exclusion of both the aneurysms with a small dog-ear of the more proximal one. The patient was discharged neurologically intact and, after one year, the remnant remained stable. Microsurgical clipping is a definitive and durable treatment for carotid-ophthalmic TandIAs. In the case of a very short minimum distance between the aneurysms, the distal one should be clipped first to make the anterior clinoidectomy, opening of the distal dural ring of the ICA, and clipping of the more proximal aneurysm easier.

Mild Head Trauma (MHT) and Antiplatelet Therapy. Reply to Lorenzati et al. Comment on "Savioli et al. Mild Head Trauma: Is Antiplatelet Therapy a Risk Factor for Hemorrhagic Complications? Medicina 2021, 57, 357".

We read your data with interest, and we truly appreciate the similar experience [...].

Mild Head Trauma: Is Antiplatelet Therapy a Risk Factor for Hemorrhagic Complications?

Background and objectives: In patients who receive antiplatelet therapy (APT), the bleeding risk profile after mild head trauma (MHT) still needs clarification. Some studies have demonstrated an association with bleeding risk, whereas others have not. We studied the population of our level II emergency department (ED) trauma center to determine the risk of bleeding in patients receiving APT and whether bleeding results not from antiplatelet agents but rather from age. We assessed the bleeding risk, the incidence of intracranial hemorrhage (ICH) that necessitated hospitalization for observation, the need for cranial neurosurgery, the severity of the patient's condition at discharge, and the frequency of ED revisits for head trauma in patients receiving APT. Materials and Methods: This retrospective single-center study included 483 patients receiving APT who were in the ED for MHT in 2019. The control group consisted of 1443 patients in the ED with MHT over the same period who were not receiving APT or anticoagulant therapy. Our ED diagnostic therapeutic protocol mandates both triage and the medical examination to identify patients with MHT who are taking any anticoagulant or APT. Results: APT was not significantly associated with bleeding risk (p > 0.05); as a risk factor, age was significantly associated with the risk of bleeding, even after adjustment for therapy. Patients receiving APT had a greater need of surgery (1.2% vs. 0.4%; p < 0.0001) and a higher rate of hospitalization (52.9% vs. 37.4%; p < 0.0001), and their clinical condition was more severe (evaluated according to the exit code value on a one-dimensional quantitative five-point numerical scale) at the time of discharge (p = 0.013). The frequency of ED revisits due to head trauma did not differ between the two groups. Conclusions: The risk of bleeding in patients receiving APT who had MHT was no higher than that in the control group. However, the clinical condition of patients receiving APT, including hospital admission for ICH monitoring and cranial neurosurgical interventions, was more severe.

Rates of Intracranial Hemorrhage in Mild Head Trauma Patients Presenting to Emergency Department and Their Management: A Comparison of Direct Oral Anticoagulant Drugs with Vitamin K Antagonists.

Background and objectives: Anticoagulants are thought to increase the risks of traumatic intracranial injury and poor clinical outcomes after blunt head trauma. The safety of using direct oral anticoagulants (DOACs) compared to vitamin K antagonists (VKAs) after intracranial hemorrhage (ICH) is unclear. This study aims to compare the incidence of post-traumatic ICH following mild head injury (MHI) and to assess the need for surgery, mortality rates, emergency department (ED) revisit rates, and the volume of ICH. Materials and Methods: This is a retrospective, single-center observational study on all patients admitted to our emergency department for mild head trauma from 1 January 2016, to 31 December 2018. We enrolled 234 anticoagulated patients, of which 156 were on VKAs and 78 on DOACs. Patients underwent computed tomography (CT) scans on arrival (T0) and after 24 h (T24). The control group consisted of patients not taking anticoagulants, had no clotting disorders, and who reported an MHI in the same period. About 54% in the control group had CTs performed. Results: The anticoagulated groups were comparable in baseline parameters. Patients on VKA developed ICH more frequently than patients on DOACs and the control group at 17%, 5.13%, and 7.5%, respectively. No significant difference between the two groups was noted in terms of surgery, intrahospital mortality rates, ED revisit rates, and the volume of ICH. Conclusions: Patients with mild head trauma on DOAC therapy had a similar prevalence of ICH to that of the control group. Meanwhile, patients on VKA therapy had about twice the ICH prevalence than that on the control group or patients on DOAC, which remained after correcting for age. No significant difference in the need for surgery was determined; however, this result must take into account the very small number of patients needing surgery.

Trauma Coagulopathy and Its Outcomes.

Background and Objectives: Trauma coagulopathy begins at the moment of trauma. This study investigated whether coagulopathy upon arrival in the emergency room (ER) is correlated with increased hemotransfusion requirement, more hemodynamic instability, more severe anatomical damage, a greater need for hospitalization, and hospitalization in the intensive care unit (ICU). We also analyzed whether trauma coagulopathy is correlated with unfavorable indices, such as acidemia, lactate increase, and base excess (BE) increase. Material and Methods: We conducted a prospective, monocentric, observational study of all patients (n = 503) referred to the Department of Emergency and Acceptance, IRCCS Fondazione Policlinico San Matteo, Pavia, for major trauma from 1 January 2018 to 30 January 2019. Results: Of the 503 patients, 204 had trauma coagulopathy (group 1), whereas 299 patients (group 2) did not. Group 1 had a higher hemotransfusion rate than group 2. In group 1, 15% of patients showed hemodynamic instability compared with only 8% of group 2. The shock index (SI) distribution was worse in group 1 than in group 2. Group 1 was more often hypotensive, tachycardic, and with low oxygen saturation, and had a more severe injury severity score than group 2. In addition, 47% of group 1 had three or more body districts involved compared with 23% of group 2. The hospitalization rate was higher in group 1 than in group 2 (76% vs. 58%). The length of hospitalization was >10 days for 45% of group 1 compared with 28% of group 2. The hospitalization rate in the ICU was higher in group 1 than in group 2 (22% vs. 14.8%). The average duration of ICU hospitalization was longer in group 1 than in group 2 (12.5 vs. 9.78 days). Mortality was higher in group 1 than in group 2 (3.92% vs. 0.98%). Group 1 more often had acidemia and high lactates than group 2. Group 1 also more often had BE <-6. Conclusions: Trauma coagulopathy patients, upon arrival in the ER, have greater hemotransfusion (p = 0.016) requirements and need hospitalization (p = 0.032) more frequently than patients without trauma coagulopathy. Trauma coagulopathy seems to be more present in patients with a higher injury severity score (ISS) (p = 0.000) and a greater number of anatomical districts involved (p = 0.000). Head trauma (p = 0.000) and abdominal trauma (p = 0.057) seem related to the development of trauma coagulopathy. Males seem more exposed than females in developing trauma coagulopathy (p = 0.018). Upon arrival in the ER, the presence of tachycardia or alteration of SI and its derivatives can allow early detection of patients with trauma coagulopathy.

Supracerebellar "Flyover" Approach to Dumbbell Falcotentorial Meningioma Encasing the Galenic Venous System.

Falcotentorial meningiomas involve the tentorial apex and straight sinus, posing challenges when encasing the galenic venous system.1 Microneurosurgery is considered the best treatment option for large falcotentorial meningiomas because it provides a definitive cure.2 In contrast, Gamma Knife surgery mainly allows the control of smaller or residual tumors after microsurgical resection.3 Approach selection between interhemispheric supratentorial versa supracerebellar transtentorial is dictated by the displacement of the Galen vein.1,4-8Video 1 describes the critical surgical steps of the supracerebellar "flyover" approach for a Bassiouni type II dumbbell falcotentorial meningiomas encasing the galenic venous system. Preoperative embolization was ruled out due to potential additional morbidity and mortality risks.9,10 A perimedian supracerebellar infratentorial transtentorial approach was performed with the patient in ¾ prone Concorde position. After early devascularization and division of the tentorium, the meningioma was internally debulked while preserving the arachnoid plane. The posterior choroidal arteries, internal cerebral veins, basal veins of Rosenthal, and vein of Galen were carefully dissected, and the tumor was completely resected. The patient was discharged on postoperative day 3 with no deficits. Postoperative magnetic resonance imaging confirmed a Simpson grade 1 resection. Pathology revealed a grade 2 meningioma. The patient remained asymptomatic with no recurrence at a 10-year follow-up. The reported case demonstrates that the most critical factor in the choice of approach to midline dumbbell falcotentorial meningiomas is the relationship of the tumor to the galenic venous system and its tributaries.

Comparative Analysis of Antithrombotic Therapy Outcomes in Mild Traumatic Brain-Injury Patients: A Focus on Bleeding Risk and Hospital-Stay Duration.

BACKGROUND: Traumatic brain injury (TBI) in the elderly is a noteworthy pathology due to the exponential increase in population age, and the effects of antiplatelet and anticoagulation on patients' outcomes are still a matter of dispute. The aim of the present study was to evaluate the impact of various antithrombotic agents on patients with mild TBI, focusing on the risk of intracranial bleeding (ICH) and length of hospitalization (LOS). METHODS: A retrospective analysis was conducted, including patients with a diagnosis of TBI admitted to the Emergency Department between 2021 and 2022. Patients were classified according to the concurrent antithrombotic therapy as aspirin (ASA), antiplatelets, direct oral anticoagulants (DOACs), and low-molecular-weight heparin (LMWH). The primary outcome was the ICH occurrence, while the secondary outcome was the LOS. The statistical analysis was performed via logistic regression models in R and STATA 13.1 software. Fisher's exact test was used for the statistical significance. RESULTS: 267 patients with mild TBI were included; 148 were not on antithrombotic agents, 43 were on aspirin, 33 on DOACs, 5 on LMWH, 22 on antiplatelets, and 16 on VKA. Out of the total, 9 patients experienced ICH, none of which were on DOACs, LMWH, or VKA, but 4-out of 65-were on antiplatelets, and 5-out of 148-were not on antithrombotic therapies. Patients not on antithrombotic therapy had the shortest LOS at 0.46 days, while those on VKA had the longest LOS at 1.19 days; similar trends were observed for patients on DOAC and LMWH. CONCLUSIONS: The results reveal that TBI patients on anticoagulants/antiplatelets had longer hospital stays compared with those on aspirin alone. Notably, VKA was the strongest predictor for an extended LOS. Regarding ICH, patients taking only aspirin were twice as likely to experience bleeding compared with those on anticoagulants/antiplatelets. However, to achieve statistically significant evidence, further research with a larger cohort of patients is needed.

Surgical management of thoracolumbar junction fractures: An evidence-based algorithm.

Background: The management of thoracolumbar junction (TLJ) fractures, involving the restoring anatomical stability and biomechanics properties, still remains a challenge for neurosurgeons.Despite the high frequency of these injuries, specific treatment guidelines, set on biomechanical properties, have not yet been assumed. The present study is meant to propose an evidence-based treatment algorithm. The primary aim for the protocol validation was the assessment of postoperative neurological recovery. The secondary objectives concerned the evaluation of residual deformity and rate of hardware failure. Technical nuances of surgical approaches and drawbacks were further discussed. Methods: Clinical and biomechanical data of patients harboring a single TLJ fracture, surgically managed between 2015 and 2020, were collected. Patients' cohorts were ranked into 4 groups according to Magerl's Type, McCormack Score, Vaccaro PLC point, Canal encroachment, and Farcy Sagittal Index. The outcome measures were the early/late Benzel-Larson Grade and postoperative kyphosis degree to estimate neurological status and residual deformity, respectively. Results: 32 patients were retrieved, 7, 9, 8, and 8 included within group 1, 2, 3, and 4, respectively. Overall neurological outcomes significantly improved for all patients at every follow-up stage (p â€‹< â€‹0.0001). Surgeries gained a complete restoration of post-traumatic kyphosis in the entire cohort (p â€‹< â€‹0.0001), except for group 4 which experienced a later worsening of residual deformity. Conclusions: The choice of the most appropriate surgical approach for TLJ fractures is dictated by morphological and biomechanical characteristics of fracture and the grade of neurological involvement. The proposed surgical management protocol was reliable and effective, although further validations are needed.

Comparative Analysis of Surgical Working Corridors for Meckel Cave Trigeminal Schwannomas: A Quantitative Anatomic Study.

BACKGROUND AND OBJECTIVES: Volumetric analysis of the working corridors of the interdural approach to the Meckel cave may lead to a selection of routes which are anatomically more advantageous for trigeminal schwannoma resection. The herein-reported anatomic study quantitively compares the infratrochlear (IT) transcavernous, anteromedial (AM), and anterolateral (AL) corridors, highlighting their feasibility, indications, advantages, and limitations. METHODS: Anatomic boundaries and depth of Meckel cave, porus trigeminus, IT transcavernous, AM, and AL corridors were identified in 20 formalin-fixed latex-injected cadaveric heads and were subsequently measured. The corridor areas and volumes were derived accordingly. Each opening angle was also calculated. Angles and volumes were compared using analysis of variance. Statistical significance was set at a P -value <.05. RESULTS: The IT transcavernous corridor volume was greater than that of the AM and AL. The opening angle of the AM middle fossa triangle was wider than the other 2. CONCLUSION: The IT corridor can be advantageous for Meckel cave schwannomas invading the cavernous sinus and those with a notable extension into the posterior fossa because the transcavernous approach maximizes the working space into the retrosellar area. The AM middle fossa corridor is strategic in schwannomas confined to the Meckel cave with a minor extension into the posterior fossa. It raises the chance of total resection with a single approach involving the porus trigeminus opening.

Optic Foraminotomy versus Anterior Clinoidectomy for Small Superior-Projecting Paraclinoid Aneurysms: Visual and Angiographic Outcome Evaluation.

INTRODUCTION: Optic foraminotomy (OF) has been recently proposed as an alternative to anterior clinoidectomy (AC) for selected types of paraclinoid aneurysms. In this study, OF and AC were compared for small superior-projecting paraclinoid aneurysms assuming visual and angiographic results as outcome measures. Indications for OF are also discussed. METHODS: Data of patients who underwent surgery for a paraclinoid aneurysm in the last 10 years were collected across 3 tertiary hospitals. Small to regular-size and superior projecting aneurysms were sorted. Multiple and complex aneurysms were excluded. Records of patients who went through OF were compared with those of patients who underwent AC. Neurologic outcome was reported as a modified Rankin Scale. Aneurysm complete occlusion rate and rate of approach-related worsened vision were selected as outcome measures of efficacy and safety, respectively, of the OF versus AC. Unpaired t test and χ2 test were used for numerical and categorical variables, respectively. A P value less than 0.05 was considered statistically significant. RESULTS: OF and AC groups involved 18 and 25 patients, respectively. Complication rate, overall neurologic outcome, rate of approach-related worsened vision, and complete occlusion rate did not differ between the groups. The average follow-up was 51 ± 34 and 60 ± 41 months in the OF and AC groups, respectively. CONCLUSIONS: Compared to AC, OF did not show either a higher rate of approach-related worsened vision or a lower aneurysm complete occlusion rate. OF can be considered a valid alternative to the AC for small superior-projecting dorsal ICA wall paraclinoid aneurysms.

The Party Wall: Redefining the Indications of Transcranial Approaches for Giant Pituitary Adenomas in Endoscopic Era.

The evolution of endoscopic trans-sphenoidal surgery raises the question of the role of transcranial surgery for pituitary tumors, particularly with the effectiveness of adjunct irradiation. This narrative review aims to redefine the current indications for the transcranial approaches for giant pituitary adenomas in the endoscopic era. A critical appraisal of the personal series of the senior author (O.A.-M.) was performed to characterize the patient factors and the tumor's pathological anatomy features that endorse a cranial approach. Traditional indications for transcranial approaches include the absent pneumatization of the sphenoid sinus; kissing/ectatic internal carotid arteries; reduced dimensions of the sella; lateral invasion of the cavernous sinus lateral to the carotid artery; dumbbell-shaped tumors caused by severe diaphragm constriction; fibrous/calcified tumor consistency; wide supra-, para-, and retrosellar extension; arterial encasement; brain invasion; coexisting cerebral aneurysms; and separate coexisting pathologies of the sphenoid sinus, especially infections. Residual/recurrent tumors and postoperative pituitary apoplexy after trans-sphenoidal surgery require individualized considerations. Transcranial approaches still have a critical role in giant and complex pituitary adenomas with wide intracranial extension, brain parenchymal involvement, and the encasement of neurovascular structures.

Fascicular-Sparing Technique for Resection of Cerebellopontine Angle Facial Nerve Schwannoma.

Surgery of cerebellopontine angle (CPA) facial nerve schwannoma (FNS) in patients with good facial nerve function is a challenge.1-10Video 1 highlights the fascicular-sparing technique for resection of a CPA FNS. A 41-year-old male patient symptomatic with persistent headaches and tinnitus underwent a retrosigmoid approach for a right cystic CPA tumor, presumed vestibular schwannoma. Intraoperatively, the facial nerve was identified as fine multiple strands splayed around the perimetry of the tumor, which elicited a motor response at a low threshold stimulation. This finding led to the intraoperative diagnosis of FNS according to the reported criteria.5 Neuromonitoring-assisted fascicular-sparing resection technique was performed. It involved the gradual separation of the uninvolved nerve fibers using a fine-stimulating dissector at a threshold of 0.2 mA. Entry into the tumor was at a stimulation silent cyst. The tumor was debulked with preservation of the endoneurium and pulse irrigation hemostasis. A near-total resection was performed. The patient was discharged on the second postoperative day with a House-Brackman III facial nerve deficit. The deficit remained stable during the following annual follow-up visits. Resection of CPA FNS is indicated at the earliest sign of deficit. However, it might be encountered as masquerading at the surgery of an acoustic tumor. The fascicular-sparing technique is critical in avoiding injuries to the endoneurium during the resection and with the ability to preserve function. The sparing of endoneurium avoids collagenization, fibrosis, and ischemia of the nerve, which are known to be the pathologic substrate of worse functional outcomes.

Photo-Stacking Technique for Neuroanatomical High-Definition Photography and 3-Dimensional Modeling.

BACKGROUND: Three-dimensional (3D) neuroanatomical knowledge is vital in neurosurgery. Technological advances improved 3D anatomical perception, but they are usually expensive and not widely available. The aim of the present study was to provide a detailed description of the photo-stacking technique for high-resolution neuroanatomical photography and 3D modeling. METHODS: The photo-stacking technique was described in a step-by-step approach. The time for image acquisition, file conversion, processing, and final production was measured using 2 processing methods. The total number and file size of images are presented. Measures of central tendency and dispersion report the measured values. RESULTS: Ten models were used in both methods achieving 20 models with high-definition images. The mean number of acquired images was 40.6 (14-67), image acquisition time 51.50 ± 18.8 s, file conversion time 250 ± 134.6 s, processing time 50.46 ± 21.46 s and 41.97 ± 20.84 s, and 3D reconstruction time was 4.29 ± 0.74 s and 3.89 ± 0.60 s for methods B and C, respectively. The mean file size of RAW files is 1010 ± 452 megabyte (MB) and 101.06 ± 38.09 MB for Joint Photographic Experts Group files after conversion. The mean size of the final image means size is 71.9 ± 0.126 MB, and the mean file size of the 3D model means is 37.4 ± 0.516 MB for both methods. The total equipment used was less expensive than other reported systems. CONCLUSIONS: The photo-stacking technique is a simple and inexpensive method to create 3D models and high-definition images that could prove valuable in neuroanatomy training.

Brain AVMs-Related microRNAs: Machine Learning Algorithm for Expression Profiles of Target Genes.

INTRODUCTION: microRNAs (miRNAs) are a class of non-coding RNAs playing a myriad of important roles in regulating gene expression. Of note, recent work demonstrated a critical role of miRNAs in the genesis and progression of brain arteriovenous malformations (bAVMs). Accordingly, here we examine miRNA signatures related to bAVMs and associated gene expression. In so doing we expound on the potential prognostic, diagnostic, and therapeutic significance of miRNAs in the clinical management of bAVMs. METHODS: A PRISMA-based literature review was performed using PubMed/Medline database with the following search terms: "brain arteriovenous malformations", "cerebral arteriovenous malformations", "microRNA", and "miRNA". All preclinical and clinical studies written in English, regardless of date, were selected. For our bioinformatic analyses, miRWalk and miRTarBase machine learning algorithms were employed; the Kyoto Encyclopedia of Genes and Genomes (KEGG) database was quired for associated pathways/functions. RESULTS: four studies were ultimately included in the final analyses. Sequencing data consistently revealed the decreased expression of miR-18a in bAVM-endothelial cells, resulting in increased levels of vascular endodermal growth factor (VEGF), Id-1, matrix metalloproteinase, and growth signals. Our analyses also suggest that the downregulation of miR-137 and miR-195* within vascular smooth muscle cells (VSMCs) may foster the activation of inflammation, aberrant angiogenesis, and phenotypic switching. In the peripheral blood, the overexpression of miR-7-5p, miR-629-5p, miR-199a-5p, miR-200b-3p, and let-7b-5p may contribute to endothelial proliferation and nidus development. The machine learning algorithms employed confirmed associations between miRNA-related target networks, vascular rearrangement, and bAVM progression. CONCLUSION: miRNAs expression appears to be critical in managing bAVMs' post-transcriptional signals. Targets of microRNAs regulate canonical vascular proliferation and reshaping. Although additional scientific evidence is needed, the identification of bAVM miRNA signatures may facilitate the development of novel prognostic/diagnostic tools and molecular therapies for bAVMs.

Immune Landscape in PTEN-Related Glioma Microenvironment: A Bioinformatic Analysis.

Introduction: PTEN gene mutations are frequently found in the genetic landscape of high-grade gliomas since they influence cell proliferation, proangiogenetic pathways, and antitumoral immune response. The present bioinformatics analysis explores the PTEN gene expression profile in HGGs as a prognostic factor for survival, especially focusing on the related immune microenvironment. The effects of PTEN mutation on the susceptibility to conventional chemotherapy were also investigated. Methods: Clinical and genetic data of GBMs and normal tissue samples were acquired from The Cancer Genome Atlas (TCGA)-GBM and Genotype-Tissue Expression (GTEx) online databases, respectively. The genetic differential expressions were analyzed in both groups via the one-way ANOVA test. Kaplan−Meier survival curves were applied to estimate the overall survival (OS) and disease-free survival (DFS). The Genomics of Drug Sensitivity in Cancer platform was chosen to assess the response of PTEN-mutated GBMs to temozolomide (TMZ). p < 0.05 was fixed as statistically significant. On Tumor Immune Estimation Resource and Gene Expression Profiling Interactive Analysis databases, the linkage between immune cell recruitment and PTEN status was assessed through Spearman's correlation analysis. Results: PTEN was found mutated in 22.2% of the 617 TCGA-GBMs patients, with a higher log2-transcriptome per million reads compared to the GTEx group (255 samples). Survival curves revealed a worse OS and DFS, albeit not significant, for the high-PTEN profile GBMs. Spearman's analysis of immune cells demonstrated a strong positive correlation between the PTEN status and infiltration of Treg (ρ = 0.179) and M2 macrophages (ρ = 0.303). The half-maximal inhibitor concentration of TMZ was proven to be lower for PTEN-mutated GBMs compared with PTEN wild-types. Conclusions: PTEN gene mutations prevail in GBMs and are strongly related to poor prognosis and least survival. The infiltrating immune lymphocytes Treg and M2 macrophages populate the glioma microenvironment and control the mechanisms of tumor progression, immune escape, and sensitivity to standard chemotherapy. Broader studies are required to confirm these findings and turn them into new therapeutic perspectives.