The state of art of awake craniotomy in Latin American countries: a scoping review.

BACKGROUND AND OBJECTIVE: Awake craniotomy (AC) is a valuable technique for surgical interventions in eloquent areas, but its adoption in low- and middle-income countries faces challenges like limited infrastructure, trained personnel shortage, and inadequate funding. This scoping review explores AC techniques in Latin American countries, focusing on patient characteristics, tumor location, symptomatology, and outcomes. METHODS: A scoping review followed PRISMA guidelines, searching five databases in English, Spanish, and Portuguese. We included 28 studies with 258 patients (mean age: 43, range: 11-92). Patterns in AC use in Latin America were analyzed. RESULTS: Most studies were from Brazil and Mexico (53.6%) and public institutions (70%). Low-grade gliomas were the most common lesions (55%), most of them located in the left hemisphere (52.3%) and frontal lobe (52.3%). Gross-total resection was achieved in 34.3% of cases. 62.9% used an Asleep-Awake-Asleep protocol, and 14.8% used Awake-Awake-Awake. The main complication was seizures (14.6%). Mean post-surgery discharge time was 68 h. Challenges included limited training, infrastructure, and instrumentation availability. Strategies discussed involve training in specialized centers, seeking sponsorships, applying for awards, and multidisciplinary collaborations with neuropsychology. CONCLUSION: Improved accessibility to resources, infrastructure, and adequate instrumentation is crucial for wider AC availability in Latin America. Despite disparities, AC implementation with proper training and teamwork yields favorable outcomes in resource-limited centers. Efforts should focus on addressing challenges and promoting equitable access to this valuable surgical technique in the region.

Neuroinflammation in Parkinson's Disease: From Gene to Clinic: A Systematic Review.

Parkinson's disease is a neurodegenerative disease whose progression and clinical characteristics have a close bidirectional and multilevel relationship with the process of neuroinflammation. In this context, it is necessary to understand the mechanisms involved in this neuroinflammation-PD link. This systematic search was, hereby, conducted with a focus on the four levels where alterations associated with neuroinflammation in PD have been described (genetic, cellular, histopathological and clinical-behavioral) by consulting the PubMed, Google Scholar, Scielo and Redalyc search engines, including clinical studies, review articles, book chapters and case studies. Initially, 585,772 articles were included, and, after applying the inclusion and exclusion criteria, 84 articles were obtained that contained information about the multilevel association of neuroinflammation with alterations in gene, molecular, cellular, tissue and neuroanatomical expression as well as clinical-behavioral manifestations in PD.

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.

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.

Novel Technique of Head-Mounted Augmented Reality-Assisted Endovascular Neurosurgery: Proof of Concept on a Flow Model.

Augmented reality (AR) is an emerging technology in medicine that is underexplored in the endovascular neurosurgery arena. We describe a novel technique integrating the Hololens 2 head-mounted AR (HMAR) system for navigation of the intracranial circulation and simple coiling of an aneurysm silicone model. Computed tomography angiographies (CTAs) of the silicone models were obtained, simulating the preprocedural CTA obtained for patient treatments. CTA was imported into the 3-dimensional (3D) HMAR system, and a 3D hologram of the circulation was created. Using the right common carotid artery run (performed in the silicon model) as a landmark, the AR hologram was superimposed on the angiography screen (Video 1). A 5-French sheath, intermediate catheter, 0.012-inch microcatheter, and microwire were used for the purely navigational model. The same process was repeated with the aneurysm model, which was navigated with a 0.58 intermediate catheter, 0.17 microcatheter, 0.014 microwire, and 6 × 15 3D-shaped soft coil. The proximal and distal vessels of the flow model were successfully navigated using the AR hologram, which replaced the conventional roadmap. No contrast ¨puffs¨ were needed because the hologram replaced the roadmap from proximal to distal vasculature. The silicon navigational model and aneurysm model were successfully navigated using only the AR 3D model. A coil was deployed in the aneurysm model. Finally, a 3D-360-degree examination of the aneurysmal anatomy was possible during the procedure. The concept of HMAR-assisted cerebral angiography is feasible. We were able to perform the whole intracranial navigation using only the preoperative CTA. Additional refinements and fine-tuning of the registration and alignment of the hologram to the silicon model or anatomy of the patient are needed before this technology can be incorporated into clinical practice. In the meantime, the use of this tool for the training and development of endovascular skills offers valuable educational opportunities. Further advances in this direction aiming to create real 3D roadmaps are needed to decrease contrast use, radiation exposure, and navigation times.

Facial nerve electrical motor evoked potential in cerebellopontine angle tumors for its anatomical and functional preservation.

Background: Among the technical measures to preserve facial nerve (FN) function, intraoperative neuromonitoring has become mandatory and is constantly being scrutinized. Hence, to determine the efficacy of FN motor evoked potentials (FNMEPs) in predicting long-term motor FN function following cerebellopontine angle (CPA) tumor surgery, an analysis of cases was done. Methods: In 37 patients who underwent CPA surgery, FNMEPs through corkscrew electrodes positioned at C5-C6 and C6-C5 (C is the central line of the brain as per 10-20 EEG electrode placement) were used to deliver short train stimuli and recorded from the orbicularis oculi, oris, and mentalis muscles. Results: In 58 patients, triggered electromyography (EMG) was able to identify the FN during resection of tumor, but 8 out of these (4.64%) patients developed new facial weakness, whereas 3 out of 38 (1.11%) patients who had intact FN function MEP (decrement of FN target muscles - CMAPs amplitude peak to peak >50-60%), developed new facial weakness (House and Brackmann grade II to III). Conclusion: The FNMEP has significant superiority over triggered EMG when tumor is giant and envelops the FN.

Three-Stage Surgical Resection in Semisitting Position of Sphenocavernopetroclival-Foramen Magnum Meningioma: 3-Dimensional Operative Video.

Large meningiomas extending through the middle cranial fossa, posterior fossa, and foramen magnum (FM) represent a surgical challenge even for experienced skull base surgeons.1 Although decompression may be necessary for offering clinical improvement, surgical risks may involve cranial nerves and vascular injury. We present a case of a sphenocavernopetroclival-FM meningioma, with our surgical plan extending through the sphenoid region, FM, and posterior fossa to the anterior arch of C1. We designed a 2-day, 3-stage surgical strategy to achieve complete surgical resection for offering better long-term prognosis and satisfactory postoperative neurological outcome.2 The surgical plan was completed in 2 days of surgery: the first day the extradural part for achieving optimal tumor exposure and the second day the intradural part to tackle tumor resection in a 3-stage fashion. The first stage consisted in a far lateral approach to access the lower portion of the tumor extending from the FM to the spinal region; the second stage focused on the portion of the tumor extending through the inferior clivus and the petroclival region; and the third stage consisted in resecting the tumor extending from the petroclival region to the sphenoid region.3 A near-total resection was achieved, with a very small tumor remnant observed at the level of the tentorium on postoperative MRI, which was treated with radiosurgery owing to the young age of the patient. This is a 3-dimensional operative video showing the surgical steps of the tumor resection. The patient consented to the procedure and to the publication of her image.

Microsurgical Resection of a Medulla Oblongata Cavernoma: 3-Dimensional Operative Video.

Cavernous malformations occur in approximately 0.5% of the population. When it comes to the medulla oblongata, the incidence rate is around 5%.1,2 Patients with these conditions face potential risks such as hemorrhaging, substantial mortality, and morbidity. The symptoms experienced by the patient vary depending on the extent of hemorrhaging and the location of the lesion. Surgery stands as the primary and essential form of treatment in these cases.1-4 The aim of this operative video was to present the removal of a medulla oblongata cavernoma. The patient consented to the procedure and to the publication of her images and surgical video. We describe the case of a 53-year-old woman presenting with headaches and with swallowing difficulties, being tracheostomized on hospital admission. Magnetic resonance imaging showed a lesion located at the medulla oblongata. Owing to the patient's symptoms and cavernoma bleeding, surgical resection was determined. There were no adverse outcomes after surgery, and the patient evolved favorably. Postoperative imaging displayed complete removal of the cavernoma. Microsurgical resection of cavernomas in this location with neurophysiological monitoring and selection of the safe entry zone is an effective option.1-4.

Novel Hybrid Technique for Preservation of Frontal Branch of Facial Nerve: Subgaleal Preinterfascial Dissection.

OBJECTIVE: The pterional approach is the workhorse of skull-base neurosurgery, which allows virtual access to any intracranial lesion around the circle of Willis. Preserving the frontotemporal branch of the facial nerve and conserving the temporal muscle's symmetry are fundamental objectives besides the access that can be obtained through this versatile neurosurgical technique. This manuscript proposes a subgaleal preinterfascial dissection, a novel hybrid technique that provides advantages of previously described temporal muscle dissection techniques while preserving the integrity of facial nerve branches and the unobstructed broad pterional region. We describe the subgaleal preinterfascial dissection as a safe and simple to technique to achieve preservation of the facial nerve frontal branches during anterolateral approaches. METHODS: Two cadaveric heads were skillfully dissected and studied to perform a proper subgaleal preinterfascial dissection on both sides of each cadaver. Afterward, the same technique was employed in 108 patients during a pterional approach for different neurosurgical diseases, with a postoperative follow-up of 6 months. RESULTS: None of the 108 patients presented postoperative frontotemporal branch palsy during postoperative follow-up. Likewise, no complications related to the proposed technique were present. CONCLUSIONS: The subgaleal preinterfascial dissection is a reliable, safe technique that may be employed during a pterional approach with an unobstructed surgical view and excellent cosmetic and functional results, preserving the frontotemporal branch of the facial nerve.

Transcranial Doppler emboli monitoring for stroke prevention after flow diverting stents.

OBJECTIVE: Flow diverting stents (FDS) are increasingly used for the treatment of intracranial aneurysms. While FDS can provide flow diversion of parent vessels, their high metal surface coverage can cause thromboembolism. Transcranial Doppler (TCD) emboli monitoring can be used to identify subclinical embolic phenomena after neurovascular procedures. Limited data exists regarding the use of TCDs for emboli monitoring in the periprocedural period after FDS placement. We evaluated the rate of positive TCDs microembolic signals and stroke after FDS deployment at our institution. METHODS: We retrospectively evaluated 105 patients who underwent FDS treatment between 2012 and 2016 using the Pipeline stent (Medtronic, Minneapolis, MN, USA). Patients were pretreated with aspirin and clopidogrel. All patients were therapeutic on clopidogrel pre-operatively. TCD emboli monitoring was performed immediately after the procedure. Microembolic signals (mES) were classified as "positive" (<15 mES/hour) and "strongly positive" (>15 mES/hour). Clinical stroke rates were determined at 2-week and 6-month post-operatively. RESULTS: A total of 132 intracranial aneurysms were treated in 105 patients. TCD emboli monitoring was "positive" in 11.4% (n=12) post-operatively and "strongly positive" in 4.8% (n=5). These positive cases were treated with heparin drips or modification of the antiplatelet regimen, and TCDs were repeated. Following medical management modifications, normalization of mES was achieved in 92% of cases. The overall stroke rates at 2-week and 6-months were 3.8% and 4.8%, respectively. CONCLUSIONS: TCD emboli monitoring may help early in the identification of thromboembolic events after flow diversion stenting. This allows for modification of medical therapy and, potentially, preventionf of escalation into post-operative strokes.

Bipolar, high-voltage, long-duration pulsed radiofrequency ablation of the Gasserian ganglion for the treatment of trigeminal neuralgia in a patient with a cardiac implantable electronic device: illustrative case.

BACKGROUND: One of the common methods of treating trigeminal neuralgia (TN) nowadays is radiofrequency therapy. However, it has serious limitations in patients with a cardiac pacemaker because of electromagnetic interference. Therefore, it is crucial to select optimal radiofrequency ablation parameters to make this procedure safe with favorable outcomes for such patients. OBSERVATIONS: In this study, the authors present a case of a 70-year-old man with a history of cardiac pacemaker dependency and previous microvascular decompression with complaints of severe, constant facial pain. After reprogramming the cardiac implantable electronic device (CIED), the authors performed bipolar, high-voltage, long-duration pulsed radiofrequency therapy (PRFT) of the Gasserian ganglion under electrocardiography and pulse rate control in the pre-, intra-, and postoperative periods. There were no cardiovascular or neurological complications after PRFT. The patient reported relief of pain after the procedure, and at the 9-month follow-up, he was pain-free. LESSONS: This clinical case demonstrates that the use of bipolar, high-voltage PRFT for TN treatment in patients with a CIED can be safe and effective, provided that the rules and pacemaker instructions are followed. It is necessary to use ablative treatment with caution and to guide the patient in collaboration with a cardiac surgeon and an anesthesiologist resuscitator.

Differential tractography and whole brain connectometry in primary motor area gliomas resection: A feasibility study.

OBJECTIVE: Establish the evolution of the connectome before and after resection of motor area glioma using a comparison of connectome maps and high-definition differential tractography (DifT). METHODS: DifT was done using normalized quantitative anisotropy (NQA) with DSI Studio. The quantitative analysis involved obtaining mean NQA and fractional anisotropy (FA) values for the disrupted pathways tracing the corticospinal tract (CST), and white fiber network changes over time. RESULTS: We described the baseline tractography, DifT, and white matter network changes from two patients who underwent resection of an oligodendroglioma (Case 1) and an IDH mutant astrocytoma, grade 4 (Case 2). CASE 1: There was a slight decrease in the diffusion signal of the compromised CST in the immediate postop. The NQA and FA values increased at the 1-year follow-up (0.18 vs. 0.32 and 0.35 vs. 0.44, respectively). CASE 2: There was an important decrease in the immediate postop, followed by an increase in the follow-up. In the 1-year follow-up, the patient presented with radiation necrosis and tumor recurrence, increasing NQA from 0.18 in the preop to 0.29. Fiber network analysis: whole-brain connectome comparison demonstrated no significant changes in the immediate postop. However, in the 1-year follow up there was a notorious reorganization of the fibers in both cases, showing the decreased density of connections. CONCLUSIONS: Connectome studies and DifT constitute new potential tools to predict early reorganization changes in a patient's networks, showing the brain plasticity capacity, and helping to establish timelines for the progression of the tumor and treatment-induced changes.

The importance of social networks in neurosurgery training in low/middle income countries.

Introduction: Neurosurgery is evolving with new techniques and technologies, relies heavily on high-quality education and training. Social networks like Twitter, Facebook, Instagram and LinkedIn have become integral to this training. These platforms enable sharing of surgical experiences, fostering global knowledge-sharing and collaboration among neurosurgeons. Virtual conferences and courses are accessible, enhancing learning regardless of location. While these networks offer real-time communication and collaborative opportunities, they also pose challenges like the spread of misinformation and potential distractions. According to the PICO format, the target population (P) for the purpose of this paper are medical students, neurosurgical residents and consultants on the role of social media (I) in neurosurgery among Low-Middle income countries (C) with the main outcome to understand the collaborative domain of learning. Material and method: This cross-sectional survey, conducted in June-July 2023, involved 210 medical students, neurosurgery residents, fellows, and practicing neurosurgeons from low and middle-income countries. A structured questionnaire assessed social network usage for neurosurgery training, covering demographic details, usage frequency, and purposes like education, collaboration, and communication. Participants rated these platforms' effectiveness in training on a 1-5 scale. Data collection employed emails, social media groups, and direct messaging, assuring respondent anonymity. The survey aimed to understand and improve social networks' use in neurosurgery, focusing on professional development, challenges, and future potential in training. Results: In a survey of 210 participants from low and middle-income countries, 85.5% were male, 14.5% female, with diverse roles: 42.9% neurosurgery residents, 40% practicing neurosurgeons, 14.6% medical students, and 2.4% other healthcare professionals. Experience ranged from 0 to 35 years, with Mexico, Nigeria, and Kenya being the top participating countries. Most respondents rated neurosurgery training resources in their countries as poor or very poor. 88.7% used social media professionally, predominantly WhatsApp and YouTube. Content focused on surgical videos, research papers, and webinars. Concerns included information quality and data privacy. Interactive case discussions, webinars, and lectures were preferred resources, and most see a future role for social media in neurosurgery training. Conclusions: Our study underscores the crucial role of social media in neurosurgery training and practice in low and middle-income countries (LMICs). Key resources include surgical videos, research papers, and webinars. While social media offers a cost-effective, global knowledge-sharing platform, challenges like limited internet access, digital literacy, and misinformation risks remain significant in these regions.

Latex vascular injection as method for enhanced neurosurgical training and skills.

Background: Tridimensional medical knowledge of human anatomy is a key step in the undergraduate and postgraduate medical education, especially in surgical fields. Training simulation before real surgical procedures is necessary to develop clinical competences and to minimize surgical complications. Methods: Latex injection of vascular system in brain and in head-neck segment is made after washing out of the vascular system and fixation of the specimen before and after latex injection. Results: Using this latex injection technique, the vascular system of 90% of brains and 80% of head-neck segments are well-perfused. Latex-injected vessels maintain real appearance compared to silicone, and more flexible vessels compared to resins. Besides, latex makes possible a better perfusion of small vessels. Conclusions: Latex vascular injection technique of the brain and head-neck segment is a simulation model for neurosurgical training based on real experiencing to improve surgical skills and surgical results.

Head-Mounted Augmented Reality in the Planning of Cerebrovascular Neurosurgical Procedures: A Single-Center Initial Experience.

BACKGROUND: Augmented reality (AR) technology has played an increasing role in cerebrovascular neurosurgery over the last 2 decades. Hence, we aim to evaluate the technical and educational value of head-mounted AR in cerebrovascular procedures. METHODS: This is a single-center retrospective study of patients who underwent open surgery for cranial and spinal cerebrovascular lesions between April and August 2022. In all cases, the Medivis Surgical AR platform and HoloLens 2 were used for preoperative and intraoperative (preincision) planning. Surgical plan adjustment due to the use of head-mounted AR and subjective educational value of the tool were recorded. RESULTS: A total of 33 patients and 35 cerebrovascular neurosurgical procedures were analyzed. Procedures included 12 intracranial aneurysm clippings, 6 brain and 1 spinal arteriovenous malformation resections, 2 cranial dural arteriovenous fistula obliterations, 3 carotid endarterectomies, two extracranial-intracranial direct bypasses, two encephaloduroangiosynostosis for Moyamoya disease, 1 biopsy of the superficial temporal artery, 2 microvascular decompressions, 2 cavernoma resections, 1 combined intracranial aneurysm clipping and encephaloduroangiosynostosis for Moyamoya disease, and 1 percutaneous feeder catheterization for arteriovenous malformation embolization. Minor changes in the surgical plan were recorded in 16 of 35 procedures (45.7%). Subjective educational value was scored as "very helpful" for cranial, spinal arteriovenous malformations, and carotid endarterectomies; "helpful" for intracranial aneurysm, dural arteriovenous fistulas, direct bypass, encephaloduroangiosynostosis, and superficial temporal artery-biopsy; and "not helpful" for cavernoma resection and microvascular decompression. CONCLUSIONS: Head-mounted AR can be used in cerebrovascular neurosurgery as an adjunctive tool that might influence surgical strategy, enable 3-dimensional understanding of complex anatomy, and provide great educational value in selected cases.

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.

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.

Comparison of Staged Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy in Patients with Brain Metastases > 2 cm without Prior Whole Brain Radiotherapy: A Systematic Review and Meta-Analysis.

OBJECTIVE: To compare fractionated stereotactic radiotherapy (FSRT) with staged stereotactic radiosurgery (SSRS) in patients with brain metastases >2 cm without prior whole brain radiotherapy. METHODS: In this systematic review and meta-analysis, PubMed, Scopus, Web of Science, Embase, and Cochrane were searched to include studies that evaluated FSRT and/or SSRS for brain metastases >2 cm or 4 cm3 in adult patients with a known primary malignancy and no prior history of whole brain radiotherapy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and an indirect random-effect meta-analyses was conducted to compare treatment outcomes between the two modalities. RESULTS: A total of 10 studies were included, comprising 612 (778 metastases) and 250 patients (265 metastases) in the SSRS and FSRT groups, respectively. The SSRS group had significantly older patients (66.6 ± 17.51 years vs. 62.37 ± 37.89 years; P = 0.029) with lower rate of control of primary disease (11.59% vs. 78.7%, P < 0.00001), and more patients with Karnofsky performance status ≥70 at baseline (92.81% vs. 88.56%; P = 0.045). FSRT was associated with a statistically nonsignificant but clinically important lower 12-month overall survival (44.75% [95% confidence interval [CI]: 30.48%-59.95%] vs. 53.25% [95%CI: 45.15%-61.19%], P = 0.1615) and higher rate of salvage radiotherapy (18.18% [95%CI: 8.75%-34%] vs. 12.27% [95%CI: 5.98%-23.53%], P = 0.0841). Both groups had comparable rates of local tumor control, mortality, tumor progression, recurrence, neurological death, and 6-month overall survival. CONCLUSIONS: SSRS and FSRT were found to be comparable for treating brain metastases >2 cm not previously irradiated. Given the paucity of such studies, trials directly comparing the two treatment strategies are warranted to support these findings.