Endoscopic transorbital approach in children: surgical technique and early results.

OBJECTIVE: In this study, the authors aimed to describe the endoscopic transorbital approach (ETOA) in children. METHODS: Six pediatric patients (2 girls and 4 boys) underwent the ETOA for paramedian skull base lesions at a single institution between September 2016 and February 2023. RESULTS: The median age at the time of surgery was 7.5 (range 4-18) years. The median follow-up period was 33 (range 9-60) months. In this series, the ETOA level of difficulty included stage 1 (n = 2, 33.3%), stage 3 (n = 3, 50%), and stage 5 (n = 1, 16.7%). The ETOA was performed for tumor resection in 4 cases; the final pathology consisted of fibrous dysplasia, pilocytic astrocytoma, metastatic neuroblastoma, and choroid plexus papilloma. The procedure was also performed for repair of a petrous apex meningocele and for lateral orbital wall decompression of traumatic lateral rectus muscle entrapment. One patient experienced a transient cranial nerve III palsy after the procedure. There were no operative deaths in this series. CONCLUSIONS: In select cases, the ETOA can be considered a minimally invasive alternative for conventional skull base approaches in the armamentarium of pediatric skull base surgery. Further investigation and the accumulation of experience are warranted in the future to enhance the efficacy and applicability of the ETOA in pediatric patients.

Open-door extended endoscopic transorbital technique to the paramedian anterior and middle cranial fossae: technical notes, anatomomorphometric quantitative analysis, and illustrative case.

OBJECTIVE: The superior eyelid endoscopic transorbital approach (SETOA) provides a direct and short minimally invasive route to the anterior and middle skull base. Nevertheless, it uses a narrow corridor that limits its angles of attack. The aim of this study was to evaluate the feasibility and potential benefits of an "extended" conservative variant of the "standard" endoscopic transorbital approach-termed "open-door"-to enhance the exposure of lesions affecting the paramedian aspect of the anterior and middle cranial fossae. METHODS: First, the authors described the technical nuances of the open-door extended transorbital approach (ODETA). Next, they documented its morphometric advantages over standard SETOA. Finally, they provided a clinical-anatomical application to demonstrate enhanced exposure and better angles of attack to treat lesions occupying the paramedian anterior and middle cranial fossae. Five adult cadaveric specimens (10 sides) initially underwent standard SETOA and then extended open-door SETOA (ODETA to the paramedian anterior and middle fossae). The adjunct of hinge-orbitotomy, through three surgical steps and straddling the frontozygomatic suture, converted conventional SETOA to its extended open-door variant. CT scans were performed before dissection and uploaded to the neuronavigation system for quantitative analysis. The angles of attack on the axial plane that addressed four key landmarks, namely the tip of the anterior clinoid process (ACP), foramen rotundum (FR), foramen ovale (FO), and trigeminal impression (TI), were calculated for both operative techniques and compared. RESULTS: Hinge-orbitotomy of the extended open-door SETOA resulted in several surgical, functional, and esthetic advantages: it provided wider axial angles of attack for each of the target points, with a gain angle of 26.68° ± 1.31° for addressing the ACP (p < 0.001), 29.50° ± 2.46° for addressing the FR (p < 0.001), 19.86° ± 1.98° for addressing the FO (p < 0.001), and 17.44° ± 2.21° for addressing the lateral aspect of the TI (p < 0.001), while hiding the skin scar, avoiding temporalis muscle dissection, preserving flap vascularization, and decreasing the rate of bone infection and degree of orbital content retraction. CONCLUSIONS: The extended open-door technique may be specifically suited for selected patients affected by paramedian anterior and middle fossae lesions, with prevalent anteromedial extension toward the anterior clinoid, the foremost compartment of the cavernous sinus and FR and not completely controlled with the pure endoscopic transorbital approach.

360° around the orbit: key surgical anatomy of the microsurgical and endoscopic cranio-orbital and orbitocranial approaches.

OBJECTIVE: Several pathologies either invade or arise within the orbit. These include meningiomas, schwannomas, and cavernous hemangiomas among others. Although several studies describing various approaches to the orbit are available, no study describes all cranio-orbital and orbitocranial approaches with clear, surgically oriented anatomical descriptions. As such, this study aimed to provide a comprehensive guide to the microsurgical and endoscopic approaches to and through the orbit. METHODS: Six formalin-fixed, latex-injected cadaveric head specimens were dissected in the surgical anatomy laboratory at the authors' institution. In each specimen, the following approaches were modularly performed: endoscopic transorbital approaches (ETOAs), including a lateral transorbital approach and a superior eyelid crease approach; endoscopic endonasal approaches (EEAs), including those to the medial orbit and optic canal; and transcranial approaches, including a supraorbital approach, a fronto-orbital approach, and a 3-piece orbito-zygomatic approach. Each pertinent step was 3D photograph-documented with macroscopic and endoscopic techniques as previously described. RESULTS: Endoscopic endonasal approaches to the orbit afforded excellent access to the medial orbit and medial optic canal. Regarding ETOAs, the lateral transorbital approach afforded excellent access to the floor of the middle fossa and, once the lateral orbital rim was removed, the cavernous sinus could be dissected and the petrous apex drilled. The superior eyelid approach provides excellent access to the anterior cranial fossa just superior to the orbit, as well as the dura of the lesser wing of the sphenoid. Craniotomy-based approaches provided excellent access to the anterior and middle cranial fossa and the cavernous sinus, except the supraorbital approach had limited access to the middle fossa. CONCLUSIONS: This study outlines the essential surgical steps for major cranio-orbital and orbitocranial approaches. Endoscopic endonasal approaches offer direct medial access, potentially providing bilateral exposure to optic canals. ETOAs serve as both orbital access and as a corridor to surrounding regions. Cranio-orbital approaches follow a lateral-to-medial, superior-to-inferior trajectory, progressively allowing removal of protective bony structures for proportional orbit access.

Endoscopic transorbital approach bone pillars: a comprehensive stepwise anatomical appraisal.

OBJECTIVE: The endoscopic superior eyelid transorbital approach has garnered significant consideration and gained popularity in recent years. Detailed anatomical knowledge along with clinical experience has allowed refinement of the technique as well as expansion of its indications. Using bone as a consistent reference, the authors identified five main bone pillars that offer access to the different intracranial targeted areas for different pathologies of the skull base, with the aim of enhancing the understanding of the intracranial areas accessible through this corridor. METHODS: The authors present a bone-oriented review of the anatomy of the transorbital approach in which they conducted a 3D analysis using Brainlab software and performed dry skull and subsequent cadaveric dissections. RESULTS: Five bone pillars of the transorbital approach were identified: the lesser sphenoid wing, the sagittal crest (medial aspect of the greater sphenoid wing), the anterior clinoid, the middle cranial fossa, and the petrous apex. The associations of these bone targets with their respective intracranial areas are reported in detail. CONCLUSIONS: Identification of consistent bone references after the skin incision has been made and the working space is determined allows a comprehensive understanding of the anatomy of the approach in order to safely and effectively perform transorbital endoscopic surgery in the skull base.

Surgical management of large lower cranial nerves schwannomas: long term results of a less aggressive resection strategy.

In an effort to reduce the high morbidity and life-threatening complications after radical resection in large schwannoma surgery, alternative strategies of nontotal resections have emerged. To evaluate the long term clinical and oncological outcome after lower cranial nerves (LCN) schwannoma surgery operated on with a cranial nerve-sparing technique. Single center retrospective cohort study of 8 consecutive patients harboring LCN schwannomas operated on between March 2005 and October 2021. The mean LCN schwannoma diameter was 33 mm (range 26-51). Seven patients (87,5%) underwent a modified retrosigmoid approach. Three patients underwent gross total resection (37,5%), 3 had received neartotal resection (mean tumor residue 0,25 cc) and subtotal resection in 2 patients who presented with an extracranial extension of the tumor (mean tumor residue 2,44 cc). Both patients had received upfront additional GKRS. The three patients who presented with preoperative CN IX & X injuries recovered within 6 months after surgery. All of the five patients freed from any preoperative CNs IX & X symptoms experienced transient (80%) or definitive (one patient) disturbances after surgery. They all improved within 6 months but one who required long term gastrostomy feeding tube. This patient harbored a schwannoma originating from the glossopharyngeal nerve, which could not be anatomically preserved during surgery. Tumor control was achieved in 100% of cases with a mean follow-up of 91 months. LCN schwannomas could be surgically removed through a less aggressive non-radical resection strategy with acceptable functional results and excellent tumor control.

The lateral retrocanthal transorbital endoscopic approach to the middle fossa: cadaveric stepwise approach and review of quantitative cadaveric data.

OBJECTIVE: The lateral retrocanthal transorbital endoscopic approach (LRCTEA) facilitates trajectory to the middle fossa, preserving the lateral canthal tendon and thus avoiding postoperative complications such as eyelid malposition. Here, the authors sought to define the surgical anatomy and technique of LRCTEA using a stepwise approach in cadaveric heads and offer an in-depth examination of existing quantitative data from cadaveric studies. METHODS: The authors performed LRCTEA to the middle cranial fossa under neuronavigation in 7 cadaveric head specimens that underwent high-resolution (1-mm) CT scans preceding the dissections. RESULTS: The LRCTEA provided access to middle fossa regions including the cavernous sinus, Meckel's cave, and medial temporal lobe. The trajectories and endpoints of the approach were confirmed using electromagnetic neuronavigation. A stepwise approach was delineated and recorded. CONCLUSIONS: The authors' cadaveric study delineates the surgical anatomy and technique of the LRCTEA, providing a stepwise approach for its implementation. As these approaches continue to evolve, their development and refinement will play an important role in expanding the surgical options available to neurosurgeons, ultimately improving outcomes for patients with complex skull base pathologies. The LRCTEA presents a promising advancement in skull base surgery, particularly for accessing challenging middle fossa regions. However, surgeons must remain vigilant to potential complications, including transient diplopia, orbital hematoma, or damage to the optic apparatus.

Advances in Intraoperative Imaging for Vascular Neurosurgery.

Cerebrovascular surgery has many intraoperative imaging modalities available. Modern technologies include intraoperative digital subtraction angiogram, indocyanine green (ICG) angiography, relative fluorescent measurement with ICG, and ultrasound. Each of these can be used effectively in the treatment of open aneurysm and arteriovenous malformation surgeries, in addition to arteriovenous fistula surgery, and cerebral bypass surgery.

Resection of the quadrangular lobule of the cerebellum to increase exposure of the cerebellomesencephalic fissure: an anatomical study with clinical correlation.

OBJECTIVE: The lateral aspect of the cerebellomesencephalic fissure frequently harbors vascular pathology and is a common surgical corridor used to access the pons tegmentum, as well as the cerebellum and its superior and middle peduncles. The quadrangular lobule of the cerebellum (QLC) represents an obstacle to reach these structures. The authors sought to analyze and compare exposure of the cerebellar interpeduncular region (CIPR) before and after QLC resection and provide a case series to evaluate its clinical applicability. METHODS: Forty-two sides of human brainstems were prepared with Klingler's method and dissected. The exposure area before and after resection of the QLC was measured and statistically studied. A case series of 59 patients who underwent QLC resection for the treatment of CIPR lesions was presented and clinical outcomes were evaluated at 1-year follow-up. RESULTS: The anteroposterior surgical corridor of the CIPR increased by 10.3 mm after resection of the QLC. The mean exposure areas were 42 mm2 before resection of the QLC and 159.6 mm2 after resection. In this series, ataxia, extrapyramidal syndrome, and akinetic mutism were found after surgery. However, all these cases resolved within 1 year of follow-up. Modified Rankin Scale score improved by 1 grade, on average. CONCLUSIONS: QLC resection significantly increased the exposure area, mainly in the anteroposterior axis. This surgical strategy appears to be safe and may help the neurosurgeon when operating on the lateral aspect of the cerebellomesencephalic fissure.

Minimally invasive keyhole approach for supramaximal frontal glioma resections: technical note.

OBJECTIVE: The authors aimed to review the frontal lobe's surgical anatomy, describe their keyhole frontal lobectomy technique, and analyze the surgical results. METHODS: Patients with newly diagnosed frontal gliomas treated using a keyhole approach with supramaximal resection (SMR) from 2016 to 2022 were retrospectively reviewed. Surgeries were performed on patients asleep and awake. A human donor head was dissected to demonstrate the surgical anatomy. Kaplan-Meier curves were used for survival analysis. RESULTS: Of the 790 craniotomies performed during the study period, those in 47 patients met our inclusion criteria. The minimally invasive approach involved four steps: 1) debulking the frontal pole; 2) subpial dissection identifying the sphenoid ridge, olfactory nerve, and optic nerve; 3) medial dissection to expose the falx cerebri and interhemispheric structures; and 4) posterior dissection guided by motor mapping, avoiding crossing the inferior plane defined by the corpus callosum. A fifth step could be added for nondominant lesions by resecting the inferior frontal gyrus. Perioperative complications were recorded in 5 cases (10.6%). The average hospital length of stay was 3.3 days. High-grade gliomas had a median progression-free survival of 14.8 months and overall survival of 23.9 months. CONCLUSIONS: Keyhole approaches enabled successful SMR of frontal gliomas without added risks. Robust anatomical knowledge and meticulous surgical technique are paramount for obtaining successful resections.

Factors influencing postoperative visual improvement in 208 patients with tuberculum sellae meningiomas.

OBJECTIVE: Tuberculum sellae meningiomas (TSMs) usually compress the optic nerve and optic chiasma, thus affecting vision. Surgery is an effective means to remove tumors and improve visual outcomes. On a larger scale, this study attempted to further explore and confirm the factors related to postoperative visual outcomes to guide the treatment of TSMs. METHODS: Data were obtained from 208 patients with TSMs who underwent surgery at our institution between January 2010 and August 2022. Demographics, ophthalmologic examination results, imaging data, extent of resection, radiotherapy status, and surgical approaches were included in the analysis. Univariate and multivariate logistic regressions were used to assess the factors that could lead to favorable visual outcomes. RESULTS: The median follow-up duration was 63 months, and gross total resection (GTR) was achieved in 174 (83.7%) patients. According to our multivariate logistic regression analysis, age < 60 years (odds ratio [OR] = 0.310; P = 0.007), duration of preoperative visual symptoms (DPVS) < 10 months (OR = 0.495; P = 0.039), tumor size ≤ 27 mm (OR = 0.337; P = 0.002), GTR (OR = 3.834; P = 0.006), and a tumor vertical-to-horizontal dimensional ratio < 1 (OR = 2.593; P = 0.006) were found to be significant independent predictors of favorable visual outcomes. CONCLUSION: Age, DPVS, tumor size, GTR, and the tumor vertical-to-horizontal dimensional ratio were found to be powerful predictors of favorable visual outcomes. This study may help guide decisions regarding the treatment of TSMs.

Effects of the COVID-19 Pandemic on Everyday Neurosurgical Practice in Alsace, France: Lessons Learned, Current Perspectives, and Future Challenges-Preliminary Results of a Longitudinal Multicentric Study Registry.

Background and Objectives: The global outbreak caused by the SARS-CoV-2 pandemic disrupted healthcare worldwide, impacting the organization of intensive care units and surgical care units. This study aimed to document the daily neurosurgical activity in Alsace, France, one of the European epicenters of the pandemic, and provide evidence of the adaptive strategies deployed during such a critical time for healthcare services. Materials and Methods: The multicentric longitudinal study was based on a prospective cohort of patients requiring neurosurgical care in the Neurosurgical Departments of Alsace, France, between March 2020 and March 2022. Surgical activity was compared with pre-pandemic performances through data obtained from electronic patient records. Results: A total of 3842 patients benefited from care in a neurosurgical unit during the period of interest; 2352 of them underwent surgeries with a wide range of pathologies treated. Surgeries were initially limited to neurosurgical emergencies only, then urgent cases were slowly reinstated; however, a significant drop in surgical volume and case mix was noticed during lockdown (March-May 2020). The crisis continued to impact surgical activity until March 2022; functional procedures were postponed, though some spine surgeries could progressively be performed starting in October 2021. Various social factors, such as increased alcohol consumption during the pandemic, influenced the severity of traumatic pathologies. The progressive return to the usual profile of surgical activity was characterized by a rebound of oncological interventions. Deferrable procedures for elective spinal and functional pathologies were the most affected, with unexpected medical and social impacts. Conclusions: The task shifting and task sharing approaches implemented during the first wave of the pandemic supported the reorganization of neurosurgical care in its aftermath and enabled the safe and timely execution of a broad spectrum of surgeries. Despite the substantial disruption to routine practices, marked by a significant reduction in elective surgical volumes, comprehensive records demonstrate the successful management of the full range of neurosurgical pathologies. This underscores the efficacy of adaptive strategies in navigating the challenges imposed by the largest healthcare crisis in recent history. Those lessons will continue to provide valuable insights and guidance for health and care managers to prepare for future unpredictable scenarios.

[Endoscopic transnasal resection of clival meningiomas]. / Rezul'taty endoskopicheskogo transnazal'nogo udaleniya meningiom oblasti skata.

BACKGROUND: Surgical treatment of ventral and ventrolateral meningiomas of posterior cranial fossa is difficult in modern neurosurgery. This is due to peculiarities of approach to these areas and concentration of critical structures (cranial nerves and great vessels). Currently, endoscopic transnasal approach to these meningiomas allows partial, and in some cases, total resection. However, this technique is not widespread. OBJECTIVE: To analyze the world literature data on postoperative outcomes in patients with clival and petroclival meningiomas after endoscopic transnasal resection. MATERIAL AND METHODS: We analyzed 22 articles representing treatment of 61 patients with clival and petroclival meningiomas. RESULTS: Total or near-total resection was achieved in 22.9% of cases, subtotal resection - 40.9%, partial resection - 26.2% (data were not provided in other cases). Even partial and subtotal resection leads to significant regression of symptoms. CONCLUSION: Endoscopic transnasal surgery is a full-fledged alternative to transcranial approaches in surgical treatment of clival meningiomas. It is also an additional option for patients with petroclival meningiomas after ineffective transcranial approaches. Transnasal tumor shrinkage and devascularization lead to brainstem decompression, regression of hydrocephalus and baseline clinical symptoms.

The impact of the COVID-19 pandemic on neurosurgery in the elderly population in Sweden.

BACKGROUND: The COVID-19 pandemic prompted a refocus of health care resources to acute care which has impacted on the capacity of healthcare systems to conduct neurological surgeries. The elderly population has been shown to be particularly vulnerable to the consequences of the pandemic. Less neurosurgery can result in great impact on public health by increasing morbidity and mortality in patients with malignancies and traumatic injuries. The aim of this study was to investigate the effects of the COVID-19 pandemic on neurosurgical procedures in the elderly population in Sweden. METHODS: In this retrospective observational study, the reported incidence of all neurosurgical procedures registered in the 21 Regions of Sweden during 2015-2021 in people aged 65 year or older was collected. Surgical procedures were classified according to the NOMESCO system of classification. Neurosurgery incidence was defined as the number of NOMESCO associated interventions per 100.000 inhabitants. ICD-10 codes associated with neurosurgery-related diagnoses and deaths were also collected. Expected incidence of neurosurgery, neurosurgery-associated deaths and brain cancer diagnoses was estimated and compared to actual outcomes. Decrease in the incidence of neurosurgery was compared to regional COVID-19 incidence, other types of surgery and surgery waiting times. RESULTS: The incidence of several categories of neurosurgery decreased in Sweden during 2020 and 2021, although not as much as other surgical categories. Women were more affected than men by the decrease in neurosurgery which could be partly explained by a decrease in brain cancer diagnoses amongst women. There was an association between regional decrease in neurosurgery incidence and longer surgery waiting time. COVID-19 incidence in the region did not have an effect on regional decreases in neurosurgery incidence. CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of neurosurgical procedures performed in Sweden during 2020-2021, although not as much as in other European countries. There was regional difference in Sweden with respect to number of surgeries, and waiting time for elective surgeries although there was no increase in mortality.

Endoscopic endonasal decompression of the optic nerve in the setting of compressive lesions: how I do it.

BACKGROUND: Many lesions in the anterior skull base may compress the optic nerve (ON), leading to vision loss, and even irreversible blindness. Although decompression of the optic nerve has traditionally been achieved transcranially, the endoscopic endonasal approach (EEA) is gaining traction as a minimally invasive approach recently. METHOD: We describe the key steps of an EEA ON decompression. The relevant surgical anatomy with illustration is described. Additionally, a video detailing our technique and instruments on an illustrative case is provided. CONCLUSION: Endoscopic endonasal approach ON decompression with a straight feather blade is a feasible, minimally invasive procedure to decompress the ON in the setting of anterior skull base mass lesions.

[Surgical Simulation Using a Three-Dimensional Printer].

3D printers have been applied in bone-based surgeries, including craniofacial, plastic, oral, and orthopedic surgeries. The improved capabilities of diagnostic imaging equipment and 3D printers have enabled the development of more precise models, and research on surgical simulations and training in the field of neurosurgery is increasing. This review outlines the use of 3D printers in neurosurgery at our institution in terms of modeling methods and surgical simulations. Modeling with the powder-sticking lamination method using plaster as the material allows drilling, which is a surgical procedure. Therefore, it is useful for simulating skull base tumors, such as petrosectomy in a combined transpetrosal approach or anterior clinoidectomy in an orbitozygomatic approach. The color coding of each part of the model facilitates anatomical understanding, and meshed tumor modeling allows deep translucency. As shown above, the 3D printer's modeling ingenuity allows for useful surgical simulations for each case.

[Interactive Virtual Simulation with Haptics for Neurosurgery].

We established a unique pre-surgical simulation method by applying interactive virtual simulation(IVS)using multi-fusion three-dimensional imaging data, presenting high-quality visualization of microsurgical anatomies. Our IVS provided a realistic environment for imitating surgical manipulations, such as dissecting bones, retracting brain tissues, and removing tumors, with tactile and kinesthetic sensations delivered through a specific haptic device. The great advantage of our IVS was in deciding the most appropriate craniotomy and bone resection to create the optimal surgical window and obtain the best working space with a thorough understanding of the lesion-bone relationship. Particularly for skull-base tumors, tailoring the procedures to individual patients for craniotomy and bone resection was sufficiently achieved using our IVS. In cases of large skull base meningiomas, our IVS was also helpful preoperatively regarding tumors, as several compartments were achievable in every potentially usable surgical direction. Additionally, the non-risky realistic microsurgical environments of the IVS provided improvement in the microsurgical senses and skills of young trainees through the repetition of surgical tasks. Finally, our presurgical IVS simulation method provided a realistic environment for practicing microsurgical procedures virtually and enabled us to ascertain the complex microsurgical anatomy, determine optimal surgical strategies, and efficiently educate neurosurgical trainees.

[Usefulness of Preoperative Simulation: Skull Base Approach].

Preoperative simulation images creates an accurate visualization of a surgical field. The anatomical relationship of the cranial nerves, arteries, brainstem, and related bony protrusions is important in skull base surgery. However, an operator's intention is unclear for a less experienced neurosurgeon. Three-dimensional(3D)fusion images of computed tomography and magnetic resonance imaging created using a workstation aids precise surgical planning and safety management. Since the simulation images allows to perform virtual surgery, a déjà vu effect for the surgeon can be obtained. Additionally, since 3D surgical images can be used for preoperative consideration and postoperative verification, discussion among the team members is effective from the perspective of surgical education for residents and medical students. Significance of preoperative simulation images will increase eventually.

[Craniotomy Clipping for Cerebral Aneurysms].

Preoperative simulation is essential to safely complete neurosurgical procedures. A vascular-oriented approach is important in cerebrovascular disorder surgery, considering anatomical variations among individuals. Particularly, subarachnoid hemorrhage surgery requires a detailed simulation of a safe dissection procedure, considering the rupture point of the aneurysm, and combined computed tomography or magnetic resonance imaging images with cerebral angiography can be useful. We present a case of subarachnoid hemorrhage and introduce the preoperative simulation performed at our hospital.

[Selection of Appropriate Approaches to Preserve Brain Function for Deep Seated Brain Tumors:Our Experience of Two Posterior Thalamic Cases].

What is the most important factor to achieve successful surgery for deep-seated brain tumors with preservation of brain functions? Definitely, it is to identify the tumor origin site at which a tumor arose and select appropriate surgical approaches that immediately lead directly to the site in the early stage of surgery, minimizing damages of cortices and important white matter bundles, and controlling main arterial supply to the tumor. For this, neurosurgeons must have thorough knowledge of brain anatomy and function, and tailor the best surgical approach for each patient, based on three-dimensional anatomical simulation. For lesions situated in the posterior and lower part of the thalamus and extending to the lateral part, two "cross-court" approaches; the occipital transtentorial/falcine and infratentorial supracerebellar transtentorial approaches, provide a wide corridor to even the lateral aspect of the thalamus and early access to the posterior choroidal arteries, usually main feeders of this territory tumors, without damaging any cerebral cortices and major white matter bundles. Here, we describe the selection of approaches for two representative cases and demonstrate surgical procedures and postoperative courses.

[Intra- and perioperative imaging options in neurosurgery]. / Az intra- és perioperatív képalkotás lehetoségei az idegsebészetben.

The treatment of central nervous system tumors is still a major challenge for the oncological and neurosurgical teams. Due to the heterogeneous histological and topological characteristics of these neoplasms, every case requires individual evaluation. In addition to histology and stage, survival is largely determined by the extent of resection, which can be severely limited by the proximity of eloquent brain regions. A key component of current modern neuro-oncological care is the planning and execution of surgical intervention to ensure the longest possible progression-free survival with adequate quality of life. The simultaneous development of several pre- and intra-operative imaging modalities is making optimal therapy more and more accessible and safe. Structural, diffusion and functional MRI offers the possibility to visualize the tumor and the surrounding areas both before and during surgery. For the surgeon, the optimal intra-operative environment, orientation and visual acuity are provided by increasingly sophisticated microscopes, navigation devices, intra-operative imaging equipment, endo- and exoscopes.