[Quantitative analysis of orbit volume and eyeball position after resection of hyperostotic sphenoid wing meningioma and simultaneous orbital wall reconstruction using individual technologies]. / Kolichestvennyi analiz ob"emov glaznits i pozitsii glaznykh yablok posle udaleniya giperostoticheskikh meningiom kryl'ev osnovnoi kosti i odnomomentnoi rekonstruktsii stenok glaznitsy s ispol'zovaniem individual'nykh tekhnologii.

OBJECTIVE: To conduct a quantitative analysis of orbit volume at different stages of preparation and surgical treatment of patients with cranio-orbital meningiomas undergoing resection with simultaneous orbital wall reconstruction using 3D modeling and 3D printing technologies. MATERIAL AND METHODS: A prospective cohort non-randomized study included 24 patients with cranio-orbital meningiomas. The volumes were measured by segmenting the orbital structures using the planimetric method in the Inobitec PRO software package. Three expert neurosurgeons independently performed these measurements. The implants were modeled in Blender software. We used the intraclass correlation coefficient (ICC) and global similarity index (GSI) to analyze interrater agreement and ensure reproducibility of analysis. RESULTS: Interrater agreement on orbital markings was very high for both metrics (ICC and GSI). The ICC (A,3) for intact orbit volume was 0.99 (95% CI 0.981; 0.996, p=1.9962018^{-33}), 0.99 (95% CI 0.983; 0.996, p=1.903203^{-34}) for damaged orbit volume at the preoperative stage, 0.99 (95% CI 0.979; 0.995, p=3.5939828^{-32}) for damaged orbit volume at the stage of modeling of resection and reconstruction, 0.99 (95% CI 0.978; 0.995, p=1.1048941^{-30}) for damaged orbit volume in postoperative period. The ICC for measurements related to EI was 0.94-0.97 (very high). This analysis revealed a strong inverse relationship between EI and volume index at the preoperative stage (rho= -0.55, p=0.004987), as well as between dynamics of EI and volume indexes in perioperative period (rho= -0.59, p=0.003). We found significant relationship (p=0.006757) between implant displacement in the area of lateral orbital wall and differences of actual and theoretical volumes. CONCLUSION: The proposed method of planimetric contouring and segmentation of orbital volumes is highly accurate and reproducible. Significant patterns allow us to develop predictive models for preliminary calculation of target volume of the damaged orbit.

[Domestic software, medical devices and materials in surgery for hyperostotic craniofacial meningiomas]. / Primenenie otechestvennogo programmnogo obespecheniya, meditsinskikh izdelii i materialov v khirurgii giperostoticheskikh kraniofatsial'nykh meningiom. (Klinicheskii sluchai i obzor literatury).

OBJECTIVE: The modern concept of resection of hyperostotic craniofacial meningiomas involves the desire for one-stage surgery with excision of tumor and simultaneous extensive skull defect closure. MATERIAL AND METHODS: The authors present skull defect closure with an individual implant after resection of cranioorbital meningioma in a 61-year-old man. The neoplasm was accompanied by exophthalmos and eyelid edema. The patient underwent simultaneous microsurgical resection and skull reconstruction with an individual implant. At discharge (7 days after surgery), exophthalmos regressed to 3 mm. After 3 months, ophthalmologist revealed complete regression of exophthalmos. RESULTS: Domestic software and 3D printers were used for implant modeling and preparing the necessary physical models and molds. We intraoperatively used domestic polymer and titanium fixation systems for manufacturing and fixation of implant. CONCLUSION: This clinical case confirms that resection of hyperostotic craniofacial meningioma with simultaneous bone defect closure using domestic analogues of software, technical equipment, materials and methods is possible at all stages of this procedure.

[Comparison of methods of treatment of meningiomas invading the superior sagittal sinus]. / Sravnitel'naya otsenka metodov lecheniya meningiom, invaziruyushchikh verkhnii sagittal'nyi sinus.

There are various approaches to the treatment of patients with parasagittal meningiomas. OBJECTIVE: To optimize treatment strategy for meningiomas invading the superior sagittal sinus. MATERIAL AND METHODS: The study included 87 patients with benign parasagittal meningiomas between 2010 and 2012. Of these, 34 patients underwent surgery alone, 27 - radiotherapy, 26 - surgery and subsequent radiotherapy. Both groups were comparable in male-to-female ratio, age and localization of tumors in relation to superior sagittal sinus. The follow-up period was at least 5 years. We analyzed the effect of treatment on neurological status, Karnofsky score and tumor growth control. RESULTS: Mean volume of tumors was 43.3 cm3 in patients undergoing surgery and 6.7 cm3 in the radiotherapy group. In the combined treatment group, mean volume was 65.8 cm3 before surgery and 8.8 cm3 before irradiation. General cerebral symptoms (84%), epileptic seizures (37%) and movement disorders (31%) prevailed. Surgery provided the best results in patients with small meningiomas (<14 cm3) causing focal neurological symptoms. Isolated radiotherapy was the most effective in asymptomatic patients. Large tumors required surgery with adjuvant irradiation. CONCLUSION: Benign parasagittal meningiomas followed by focal neurological symptoms require surgical intervention regarding the best functional outcomes and tumor growth control. Radiotherapy without surgery is advisable for progressive asymptomatic tumors. Resection followed by irradiation is preferable if total resection without the risk of damage to veins and cortex is impossible.

[Complicated course of the postoperative period with the development of epidural hygroma and intracranial hypotension after removal of cranio-orbital meningioma. Clinical case and literature review]. / Oslozhnennoe techenie posleoperatsionnogo perioda s razvitiem epidural'noi gigromy i vnutricherepnoi gipotenzii posle udaleniya kranioorbital'noi meningiomy. Klinicheskii primer i obzor literatury.

Surgical removal of cranio-orbital meningiomas is an effective method of treating this pathology. Modern surgical techniques and technologies make it possible to perform operations with a low risk of complications. Lumbar drainage or repeated lumbar punctures are often used intraoperatively or in the early postoperative period to prevent nasal CSF leak; this rarely leads to the development of significant neurological symptoms. We present a case of the development of severe intracranial hypotension with the formation of a subdural hygroma in the early postoperative period after removal of a cranio-orbital meningioma in a 41-year-old patient. The operation was performed using an individual model and molds for simultaneous reconstruction of the bone defect with an implant made of polymethyl methacrylate. On the 1st and 2nd days after surgery, lumbar punctures were performed. From the 2nd day there was a progressive deterioration with the development of symptoms characteristic of intracranial hypotension. Computed tomography revealed an increasing displacement of the midline structures of the brain and an increasing volume of epidural fluid accumulation in the area of surgical intervention. Magnetic resonance imaging revealed characteristic signs of intracranial hypotension. Conservative treatment (bed rest, active hydration) had no effect. On the 6th day after surgery, an epidural blood patch procedure was performed and closed external drainage of the epidural hygroma was performed, and a rapid regression of neurological symptoms was noted. Our experience and literature data indicate that it is necessary to remember the possibility of developing clinically significant intracranial hypotension even after a single lumbar puncture. The formation of hygromas in the surgical area is characteristic of intracranial hypotension, but in most cases does not require additional surgical intervention and does not have a negative impact on the outcome of treatment. Conservative treatment of intracranial hypotension is the first choice and often sufficient. If there is no effect and the patient's condition worsens, it is necessary to perform an epidural blood patch procedure.

[Dural defect closure after resection of cranioorbital meningiomas]. / Rekonstruktsiya defektov tverdoi mozgovoi obolochki posle udaleniya kranioorbital'nykh meningiom.

Dural defect closure after resection of cranioorbital meningiomas has its own specifics. Extended malignant lesions and common large bone defects involving various anatomical regions require multiple implants or implants with complex geometry. The features of this stage of reconstruction were described in the previous issue of the Burdenko Journal of Neurosurgery. At the same time, contact of implant with nasal cavity and paranasal sinuses dictates additional requirements for tightness of soft tissue reconstruction and inertness of material. In this review, we describe modern and historically interesting methods of reconstruction of soft tissue defects following resection of cranioorbital meningioma. OBJECTIVE: To summarize and analyze available literature data on reconstruction of soft tissue defects following resection of cranioorbital meningioma. MATERIAL AND METHODS: The authors reviewed available data on reconstruction of soft tissue defects after resection of cranioorbital meningiomas. Effectiveness of reconstruction techniques and safety of materials were analyzed. RESULTS: The authors analyzed 42 available full-text articles. Features of growth and natural course of cranioorbital meningioma, methods of soft tissue defects closure, modern materials and sealing compositions are described. Considering these data, the authors proposed the algorithms for selecting materials for dural reconstruction after resection of cranioorbital meningioma. CONCLUSION: Improvement of surgical technique, development of new materials and technologies increase the efficiency and safety of dural defect closure. Nevertheless, high incidence of complications associated with dura mater repair necessitates further research in this area.

[Bone defect closure after resection of sphenoorbital meningioma]. / Rekonstruktsiya kostnykh defektov posle udaleniya kranioorbital'nykh meningiom.

Sphenoorbital meningiomas (SOM) are a subgroup of skull base tumors with soft tissue component in the orbit and anterior and/or middle cranial fossa. According to different authors, SOMs account for 2-12% of all intracranial meningiomas. Reconstruction of bone defects after resection of SOM has own nuances. Along with cranial vault repair, patients encounter with cosmetic defects following facial skull lesion, ophthalmic symptoms due to orbital defects, dental and functional problems associated with opening of the mouth in case of damage to maxilla and mandible. Predominant infiltrative growth of tumor and common large bone defects involving various anatomical regions require multiple implants or implants with complex shape. Moreover, contact of implantation area with nasal cavity and paranasal sinuses requires additional impermeability of soft tissue reconstruction and inertness of materials. OBJECTIVE: To summarize available modern data on bone defect closure after resection of SOM. MATERIAL AND METHODS: The authors reviewed available data on bone defect closure after resection of SOM. Effectiveness of modern methods of reconstruction and safety of materials were assessed. RESULTS: We analyzed 96 available references. Technical features of tumor resection, materials used for bone defect closure and modern possibilities of 3D technologies in reconstructive surgery were described. The authors proposed the algorithms for selecting the materials for bone defect closure after resection of SOM. CONCLUSION: Improvement of surgical technique and development of new materials and technologies significantly improve cosmetic and functional results. A large percentage of negative ophthalmologic outcomes and high risk of complications in SOM surgery require further studies and elaboration of modern techniques.

[Delta-He a new biomarker for a surgical clinic]. / Del'ta gemoglobina ­ novyi biomarker dlya khirurgicheskogo statsionara.

BACKGROUND: Delta-He the difference between hemoglobin content in reticulocytes and erytrocytes is a relatively new laboratory indicator that is easily measured in everyday practice. This parameter is directly related to iron bioavailability for hemoglobin synthesis and can reflect various conditions accompanied by cytokine expression including systemic inflammation. OBJECTIVE: To analyze the prospects for practical application of hemoglobin delta in assessment of neurosurgical patients throughout in-hospital treatment. MATERIAL AND METHODS: We analyzed complete blood counts (Sysmex XN-1000 analyzer) with optical determination of reticulocyte hemoglobin and automatic calculation of Delta-He in 82 neurosurgical patients. Exclusion criteria were severe decompensated comorbidities, exacerbation of chronic infectious processes, cancer of other organs. Blood sampling for analysis of delta-hemoglobin was carried out before all diagnostic and therapeutic measures. Reference interval is indicated by the analyzer manufacturer as 1.7-4.4 pg. RESULTS: Delta-He values at admission ranged from -1.8 to 6.1 pg. There was a consistent decrease of these values throughout 3-4 postoperative days. Then, the values could increase or continued to decrease. Increment of the index was noted in 76 patients (92.7%). Such dynamics was observed in case of uncomplicated postoperative period. Further decrease of Delta-He was observed in 6 patients (7.3%). These ones were characterized by a longer recovery after surgery, and the events required additional medical or surgical correction were recorded. Negative dynamics of Delta-He values could precede clinical manifestations of certain complication. Clarification of diagnosis and correction of therapy were accompanied by gradual increase of Delta-He values. CONCLUSION: Estimation of Delta-He values over time can be used for monitoring of patients and effectiveness of therapy. From a practical point of view, it is important that examination can be performed at any time of the day.

[Glioblastoma in the region of previously resected meningioma. Case report and literature review]. / Glioblastoma, voznikshaya v oblasti udalennoi meningiomy. Klinicheskoe nablyudenie i obzor literatury.

Combination of meningioma and glioblastoma within the same anatomical region is casuistry. We found only 13 case reports in the available literature. Some of the authors reported induced nature of the second tumor, i.e. development under the influence of the primary neoplasm. We report a patient with glioblastoma of the right frontoparietotemporal region in 3 years after previous resection of benign right-sided meningioma of sphenoid wings. Mathematical analysis of the discovered pattern resulted conclusion about its random nature, i.e. no causal relationship between both neoplasms.

[Transcranial microsurgical decompression of the optic canal in surgical treatment of meningiomas of the sellar region]. / Transkranial'naya mikrokhirurgicheskaya dekompressiya kanala zritel'nogo nerva v khirurgii meningiom khiazmal'no-sellyarnoi oblasti.

RATIONALE: When removing the meningiomas of the sellar region, there is always a risk of visual impairment for various reasons, in particular, as a result of traction damage to the optic nerve. Decompression of the optic canal increases nerve mobility during tumor manipulation. In cases of meningioma growing into the canal, its decompression often seems necessary. AIM: Evaluation of the effectiveness and risks of performing decompression of the optic canal. MATERIALS AND METHODS: The study included patients with meningiomas of the parasellar location, who underwent surgical treatment at the Burdenko Neurosurgical Center for the period from 2001 to 2017. They were divided into two groups - main and control. The main group consisted of 129 patients who underwent decompression of the optic nerve canals when the tumor was removed. The tumor matrix in this group was most often located in the region of the tuberum sellae, supradiaphragmally, in the region of the anterior clinoid process and the optic canal. In 31 cases, decompression was bilateral - during one operation and using one access in 27 patients; in 4 cases, the decompression of the second canal was delayed for 1.5-3 months after the first operation. 160 decompressions were performed by the intradural and 7 - by extradural methods. During intradural decompression, the roof of the optic canal was resected, and during extradural decompression, the lateral wall of the canal was trephined. The control group consisted of 308 patients who did not undergo canal decompression when the tumor was removed. It included meningiomas with a predominant location of the matrix in the area of the tuberclum and diaphragm of the sella. Tumors in both groups were removed according to the same principles (matrix coagulation, mainly the gradual removal of the tumor, the use of ultrasonic aspirator, a situational decision on the radicality of the operation, etc.). The main difference between operations in these two groups was only canal related algorithms (with or without its trepanation), as well as the probable prevalence of significant lateral tumor growth in cases with canal trepanation. Visual functions in the «primary¼ group were evaluated before and after operations with trepanation of the canal depending on various factors - the initial state of vision and the radicality of the tumor excision, including removal from the canal. The differences in the postoperative dynamics of vision in the main and control groups were studied. The primary data processing was carried out using the program MSExcel. Secondary statistical processing was carried out using the program Statistica. To assess the statistical significance of differences in the results obtained in the compared patient groups, the Chi-square test was used, and in the case of small groups - the exact Fisher test was applied. RESULTS: In the main group postoperative vision improvement of varying degrees on the side of trepanation was registered in 36.9% (59 out of 160) cases, no vision changes were found in 36.9% (59 out of 160), and in 26,2% (42 out of 160) the eyesight deteriorated. If preserving vision is attributed to a satisfactory result, then in general the results of these operations should be considered good. A comparative study of the results of removal of meningiomas with trepanation of the canals (main group) or without it (control group) was carried out among patients with the most critical vision situation (visual acuity 0.1 and below, up to only light perception). These groups are comparable in the number of observations - 62 and 73 respectively. The predominance of cases with improved vision in the main group compared with the control group (50.0% versus 38.36%) and a lower incidence of vision impairment (22.58% versus 34.25%) were found. However, the revealed differences are statistically unreliable and make it possible for us to talk only about the trend. The complications associated with trepanation of the canal include mechanical damage to the nerve by the drill. In our series of observations, there was only 1 case of abrasion of the nerve surface with the burr, which did not lead to a significant visual impairment. With the intradural method of trepanation in the area of the medial wall of the canal, the sphenoid sinus may open (in our series, in 34 cases out of 160 trepanations). Immediately closure of these defects was performed by various auto- and allomaterials in various combinations (pericranium, fascia, muscle fragment, hemostatic materials, and fibrin-thrombin glue). A true complication - CSF rhinorrhea liquorrhea developed in only one case, which required transnasal plastic surgery of the CSF fistula using a mucoperiostal flap. CONCLUSIONS: 1. Trepanation of the optic canal in cases of meningiomas of parasellar localization is a relatively safe procedure in the hands of a trained neurosurgeon and does not worsen the results of operations compared with the excision of the same tumors without trepanation of the canal. 2. The literature data and the results of our study make it possible to consider the decompression of the optic canal as an optional, but in many cases, useful option that facilitates the transcranial removal of some meningiomas of the sellar region.

[Radiation-induced meningiomas: analysis of 33 cases]. / Radioindutsirovannye meningiomy: analiz 33 nablyudenii.

BACKGROUND: Development of meningiomas correlating with irradiation has been described in the last century. Different biological features of radiation-induced meningiomas depending on dose and type of irradiation have been observed in recent years. MATERIAL AND METHODS: There were 8848 patients (women - 74.3%) with intracranial meningiomas for the period from 2000 to 2014 who underwent surgery at the Burdenko Neurosurgical Center. Radiation-induced meningiomas were identified in 33 patients (13 (38%) men and 20 (62%) women) aged 16-76 years (median 56 years). Medical data were retrospectively analyzed. Follow-up period ranged from 5 to 22 years (median 12) after verification of histological diagnosis. Meningiomas were preceded by X-ray irradiation of the scalp for ringworm (microsporia or trichophytosis) in 26 cases (79%) (group A). Group B enrolled 7 (21%) patients after previous radiotherapy for other tumors (retinoblastoma, chiasmal glioma, pituitary adenoma, basalioma). Data were compared using Mann-Whitney and Fisher's exact tests. RESULTS AND DISCUSSION: Incidence of radiation-induced meningiomas was 0.37% in our sample. Meningioma diagnosis dates after X-ray epilation (median 52 years) significantly differed from that after radiotherapy (median 22 years) (Mann-Whitney test, p=0.0003). Primary multiple meningiomas were diagnosed only in the 1st group (Fisher's exact test, p=0.0005). Recurrent meningiomas after the first surgery were more common in the first group (58%) compared to the second one (14%) (Mann-Whitney test, p=0.0003). CONCLUSIONS: The latency period is shorter after radiotherapy (median 22 years compared to 52 years after X-ray epilation). Incidence of atypical and malignant meningiomas directly correlates with irradiation dose. Approximately equal incidence of radiation-induced meningiomas after X-ray epilation in women and men can indicate other mechanisms of development of these tumors in comparison with spontaneous ones. Radiotherapy is followed by occurrence of meningiomas within the irradiated area. These tumors are usually single. In case of X-ray epilation, the tumors may be localized anywhere within the intracranial space (convexital and/or parasagittal localization in 77% of cases). Multiple neoplasms occur in 42% of cases. Refusal of head X-ray epilation for the treatment of a ringworm for the last 50 years may be followed by reduced incidence of radiation-induced meningiomas, especially multiple ones. However, extended indications for radiotherapy of various brain diseases can result an increase of the incidence of meningiomas within the irradiated area.

[Treatment of primary craniofacial (sinonasal) malignant tumors affecting the anterior and middle skull base]. / Lechenie pervichnykh kraniofatsial'nykh (sinonazal'nykh) zlokachestvennykh opukholei, porazhaiushchikh perednie i srednie otdely osnovaniia cherepa.

Sinonasal malignant tumors are characterized by high histological variability and complexity of the differential diagnosis. Currently, there are classifications of these tumors, which are based on their localization and involvement of various anatomical structures. However, generally accepted algorithms for treatment of this pathology have not yet been developed. This review describes the most important algorithms for treatment of the most common histological variants of sinonasal malignant tumors: squamous cell carcinoma, adenocarcinoma, sinonasal undifferentiated carcinoma, esthesioneuroblastoma, adenoid cystic cancer, and sinonasal adenocarcinoma. The main problems in choosing the approach for treating these tumors are the lack of generally accepted resectability criteria and contradictions between oncological and neurosurgical indications for surgical treatment. Further research is needed to study the role of radiosensitizers and radioprotectors in comprehensive treatment of sinonasal malignant tumors.

[Biopsy and resection of skull base tumors using transorbital endoscopic approaches: primary results]. / Biopsiia i udalenie novoobrazovanii osnovaniia cherepa s primeneniem transorbital'nykh éndoskopicheskikh dostupov: pervye rezul'taty.

AIM: Transorbital neuroendoscopic surgery is a new skull base surgery technique that uses the orbit as an artificial corridor to the anterior and middle skull base. The space is created between the periorbita and orbital walls by their additional resection and gentle traction of the orbital contents. Skull base structures are reached using cosmetic incisions. The major advantages of transorbital endoscopic approaches include their variety, possibility of their combination, and access to the central and lateral skull base lesions. The aim of this study was to analyze the primary results of transorbital endoscopic biopsy and resection of skull base lesions, which were performed at the N.N. Burdenko National Medical Research Center for Neurosurgery (Moscow, Russia). MATERIAL AND METHODS: In 2017-2018, the authors operated on 12 patients with skull base lesions using transorbital endoscopic approaches. The series included ten female and two male patients. The patient's age varied between 24 and 78 years. All patients were admitted for the first time. Half of them underwent biopsy, while the other half underwent tumor resection. The upper-lateral transorbital approach with an eyebrow incision was used in most (8/12) patients; the retrocaruncular approach was used in two cases; the lateral retrocanthal approach was applied in one case; the upper-medial approach with an eyebrow incision was used in one patient. RESULTS: The histological diagnosis was established in all six biopsies: 3 pseudotumors, 2 WHO Grade I meningiomas, and 1 clear-cell kidney cancer. Tumor resection was successful in 5 out of 6 patients; repeated surgery was required in one patient. In one case, the transorbital approach was combined with the transnasal one for treatment of supraorbital mucocele. One patient developed a persistent neurological deficit (dysfunction of the fifth and sixth nerves) after upper-lateral transorbital surgery. There were no poor cosmetic results in the series. CONCLUSION: Transorbital neuroendoscopic surgery needs an interdisciplinary approach and a sufficient amount of surgical experience. Surgical skills setting includes microsurgical and endoscopic tumor resection, harvesting and positioning of free and vascularized grafts for skull base reconstruction and prevention of postoperative enophthalmos, and facial incisions and their cosmetic closure. Implementation of new local vascularized flaps may significantly improve the results of transorbital endoscopic procedures and extend the spectrum of indications.

[The orbitozygomatic approach. History, technique, and modifications]. / Orbitozigomaticheskii dostup. Istoriia, tekhnika, modifikatsii.

The orbitozygomatic approach (OZA) has been used in neurosurgical practice since the 1980s. Many approach modifications have been proposed; anatomical and clinical developments have been conducted in many clinics. However, there is no algorithm for choosing an approach option, depending on the type and topographo-anatomical features of pathology. MATERIAL AND METHODS: We searched for publications in the PubMed and Medscape databases using the keywords 'orbitozygomatic'. RESULTS: A total of 447 publications matching the search terms were found. In most of them, the approach was either not actually orbitozygomatic or was mentioned in the description of a clinical case. One hundred and nineteen full text Russian or English papers were available for detailed analysis. Of these, we selected 72 most relevant publications. DISCUSSION: There were no studies demonstrating disadvantages of the OZA compared to traditional craniotomies. Orbitozygomatic approaches are widely used in routine neurosurgical practice. Existing approaches are not without disadvantages. The publications are based on small material. The recommendations on choosing the optimal OZA option are based on the authors' opinion, i.e. they satisfy the minimum level of evidence. There are no studies comparing the efficacy of OZA options in different types and topographo-anatomical variants of neurosurgical pathology of the anterior and middle skull base. CONCLUSION: The reasonability of using the orbitozygomatic approach in neurosurgical practice is obvious. There are a large number of orbitozygomatic approaches and their modifications. The modern literature lacks an algorithm for choosing the optimal OZA option for specific types and topographo-anatomical variants of the pathological process.

[An anatomical study on the applicability of direct endoscopic exclusion of the ethmoid arteries for devascularization of the anterior skull base structures]. / Anatomicheskoe issledovanie vozmozhnosti priamogo éndoskopicheskogo vykliucheniia reshetchatykh arterii dlia devaskuliarizatsii struktur perednikh otdelov osnovaniia cherepa.

The anterior skull base structures are the site of initial growth of histologically different tumors. The difficulties in their removal are often associated with significant vascularization, which may limit the amount of resection due to abundant intraoperative blood loss. Midline tumors are primarily fed by the ethmoid arteries that are not accessible to embolization. The aim of this work was a comparative experimental study of various direct approaches to the ethmoid arteries. MATERIAL AND METHODS: The study was conducted on anatomical specimens of 12 cadaveric heads of deceased people without pathology of the anterior skull base structures, orbits, nasal cavity, and paranasal sinuses (24 sides). In all specimens, the internal and external carotid arteries were stained with silicone. During anatomical dissection, four surgical approaches for exclusion of the ethmoid arteries were studied: 1) transorbital approach to the arteries using a bicoronal incision; 2) endoscopic retro-caruncular approach; 3) endoscopic endonasal transethmoidal approach to the ethmoid artery canals; 4) endoscopic endonasal transethmoidal transorbital approach to the ethmoid arteries in the orbit. RESULTS: We described a surgical technique for exclusion of the ethmoid arteries using the approaches and analyzed their advantages and disadvantages. We formulated an algorithm for choosing the method for direct endoscopic exclusion of the ethmoid arteries, depending on the surgical approach chosen for removal of the tumor and features of the tumor extracranial spread. CONCLUSION: The decision on tumor devascularization is based on assessment of tumor blood supply (CT angiography or MR angiography data). Our study demonstrated the advantages and disadvantages of various approaches to the ethmoid arteries for their exclusion in order to early devascularize anterior skull base tumors. All these approaches are less traumatic and characterized by a good cosmetic and functional outcome.

[Neurological semiotics of benign craniofacial tumors]. / Nevrologicheskaia semiotika dobrokachestvennykh kraniofatsial'nykh opukholei.

AIM: To identify the most frequently occurring symptoms resulting from the affection of internal and external skull base in patients with benign tumors of the anterior and middle cranial base. MATERIAL AND METHODS: The authors analyzed a complex of history, clinical, and instrumental data as well as results of combined treatment of 642 patients with benign tumors of the anterior and middle cranial base operated Medical Research between 2007 and 2011. RESULTS: Neurological signs and symptoms in patients with benign tumors of the anterior cranial base, parasellar region, and middle cranial fossa were studied. In the majority of cases, the tumor extended extracranially. The most common groups of symptoms were identified and described, the most important groups are presented in the diagrams. The proposed scheme is applicable also for malignant tumors or other mass lesions of the same localization. CONCLUSION: Effective treatment and selection of the best management of a patient depends on modern medical approaches and techniques including neuroimaging. Careful assessment of symptoms is crucial in detection of tumors in the early stage. Dynamic monitoring of the patient using the proposed scheme will contribute to early detection of tumor recurrence or progression.

[Variability and age-related features of the anatomy of the midline structures of the anterior skull base]. / Variabel'nost' i vozrastnye osobennosti anatomii sredinnykh struktur perednikh otdelov osnovaniia cherepa.

The article presents the literature data on the structural variability and age-related features of the midline anatomical structures of the anterior skull base (frontal sinus, ethmoid bone, anterior parasellar region, and medial orbital wall). This is the area of surgical interests of neurosurgeons and rhinosurgeons. The study objective is to analyze the literature data on the individual variability and age-related anatomy of these structures. The work is illustrated with original images from the authors' personal archive. The individual anatomical features of eloquent structures in the surgical area (structures within the surgical corridor, key anatomical landmarks, optic tract, internal carotid and ethmoidal arteries, etc.) should be considered in planning surgery in patients of all age groups because they can limit the view and the amount of safe manipulations or increase the risk of complications. The presented data may be useful for neurosurgeons and otolaryngologists whose surgical interests are focused on the midline structures of the anterior skull base.

[Craniofacial tumors blood supply]. / Krovosnabzhenie kraniofatsial'nykh opukholei.

Because of the spread to different anatomical regions, craniofacial tumors (CFTs) usually receive blood supply from several arterial systems, and CFT removal is often accompanied by abundant blood loss. PURPOSE: The study purpose was to develop an algorithm of diagnostic angiography for planning surgical treatment of CFT patients. MATERIAL AND METHODS: Complex preoperative angiography was performed in 72 patients with craniofacial tumors, aged 10 to 78 years (mean age, 45.5 years), who underwent surgical treatment at the Burdenko Neurosurgical Institute in the period from 2012 to 2015. At the first stage, blood supply to tumors was quantified using SCT perfusion. Then, depending on an assessed degree of tumor vascularization, direct angiography or modern minimally invasive angiographic techniques (3D TOF HR MR angiography, SCT angiography) were applied. RESULTS: In 12 cases of hypervascular tumors, accessible afferents were preoperatively embolized through the external carotid artery, which was accompanied by an increase in the blood supply to tumors via alternative routes of the external and internal carotid arteries. The obtained data were used to plan the surgical approach. A comparative analysis of the SCT perfusion data and the expression level of endothelial markers in histological specimens revealed no significant correlation. CONCLUSION: The study demonstrated the importance of a comprehensive assessment of the blood supply to CFTs in planning of the surgical treatment and enabled the development of algorithms for preoperative angiographic diagnosis, depending on the baseline clinical and radiological data.

[Choosing an anterior midline approach to skull base tumors]. / Vybor perednego sredinnogo dostupa pri opukholiakh osnovaniia cherepa.

The purpose of this review is to analyze used anterior midline approaches to the skull base, identify their advantages and disadvantages, and, after reviewing the literature data, submit a developed algorithm for choosing an optimal approach to the approval of colleagues. We provide brief information on approach techniques, indications and contraindications, and advantages and disadvantages as well as analyze international experience of using the discussed approaches. On the basis of literature data, we have developed a prototype algorithm for choosing an optimal approach to medial tumors of the anterior skull base. The situation of choosing an optimal approach reveals the absence of a clear understanding of the boundaries between capabilities and limitations of approaches. To solve this problem, an original prospective study is required.

[Epidemiology, diagnosis, clinical symptoms, and classification of malignant primary skull base tumors]. / Épidemiologiia, diagnostika, klinicheskaia simptomatika i klassifikatsiia pervichnykh zlokachestvennykh opukholei, porazhaiushchikh osnovanie cherepa.

A review of literature presents up-to-date information on the prevalence, incidence, clinical manifestations, diagnosis, and classification of malignant primary skull base tumors (MPSBTs). In the structure of total cancer incidence, malignant head and neck tumors account for 5% of all annual cancer deaths in the USA and are among the 5 most common groups of tumors in males worldwide. These tumors develop most often in the sixth decade of life, occurring 2 times more often in males than in females. In Russia, the MPSBT incidence (as of 2012) was 0.62% out of all newly diagnosed malignant tumors. The incidence rate amounts to 0.66 per 100 000 population and is significantly higher than the global rate (0.44 per 100 000). About half of all malignant skull base tumors have the epithelial nature and affect the anterior parts of the skull base. The most frequent histological types of malignant skull base tumors are squamous cell carcinoma, adenocarcinoma, and non-Hodgkin's B cell lymphoma. Treatment of skull base tumors is an interdisciplinary problem and the area of interest of otolaryngologists, dentists, ophthalmologists, neurosurgeons, plastic surgeons, radiologists, and chemotherapists. Physical and endoscopic examinations, endoscopic transnasal biopsy, CT, MRI, PET/CT, and ultrasound are typically used for verification of the diagnosis, tumor staging, and selection of the treatment approach. The review describes the criteria for TNM staging of malignant tumors of the nasal cavity and paranasal sinuses in accordance with the 7th version of the TNM recommendations of the American Joint Committee on Cancer (AJCC). The TNM-based staging depends on the location (maxillary sinus, nasal cavity, or ethmoid labyrinth) and histological structure of the tumor, which, in turn, determines the tactics of comprehensive treatment and a prognosis group.

[Orbitozygomatic approaches to skull base tumors spreading into the orbit, paranasal sinuses, nasal cavity, and pterygopalatine and infratemporal fossae].

The paper analyzes application of orbitozygomatic approaches at the Department of Skull Base and Craniofacial Surgery of the Burdenko Neurosurgical Institute for a 14-year period. During this time, 723 patients were operated on using the orbitozygomatic approach, which has become the workhorse of surgery for skull base tumors spreading into the orbit, paranasal sinuses, and pterygopalatine and infratemporal fossae. The authors describe seven major modifications of the orbitozygomatic approach that they have used in their practice.