[Results of surgical treatment of children with Chiari I malformation using differentiated intraoperative tactics of choosing the volume of intervention]. / Rezul'taty khirurgicheskogo lecheniya detei s mal'formatsiei Kiari I tipa pri primenenii differentsirovannoi intraoperatsionnoi taktiki vybora ob"ema vmeshatel'stva.

BACKGROUND: Despite the presence of numerous publications and analytical reviews in the foreign literature, there is no universally accepted algorithm for the surgical treatment of Chiari I malformation (MC I) in children. Moreover, in the domestic literature, the number of publications devoted to the problems of surgical treatment of MC I in children is significantly limited, which, in our opinion, this is the reason for the relevance of this work. OBJECTIVE: To study the results of surgical treatment of children with MC I when applying differentiated tactics of intraoperative choice of intervention volume. MATERIAL AND METHODS: The results of neurological examination and surgical treatment of 43 patients aged from 1 to 17 years (mean age 8.48 years) were analyzed. The decision on the need for duraplasty was made intraoperatively when signs of persisting compression of subarachnoid spaces after extradural decompression were detected. Clinical manifestations were assessed according to neurological data before discharge, as well as in long-term period with a follow-up from 6 months to 5 years via survey. RESULTS: Duraplasty was required in 28% of cases. Respiratory disorders disappeared in all patients immediately after surgery and were absent thereafter. Positive dynamics was noted in terms of restoration of the rate of speech development. Headache persisted in 7 (21%) patients, movement, sensation disorders and cerebellar symptoms - in 4 (12%), vomiting and bulbar symptoms - in 2 (6%) patients. There was no difference in the efficacy of surgery with and without duraplasty. None of the parameters evaluated preoperatively had a significant association with the intraoperative decision on the need for duraplasty. CONCLUSION: In our opinion, final decision on surgical strategy in children with Chiari malformation type I should be made considering intraoperative assessment of extradural decompression. The last one is probably associated with individual characteristics of patients.

[MR morphometry in epileptology: progress and perspectives]. / Primenenie MR-morfometrii v epileptologii: dostizheniya i perspektivy.

Morphometric MRI analysis improves neuroimaging of structural changes in epilepsy. OBJECTIVE: To investigate diagnostic potential of MR brain morphometry in neurosurgical epileptology. MATERIAL AND METHODS: An interdisciplinary working group reviewed the studies devoted to MR morphometry in epileptology as a part of state assignment No. 056-00119-22-00. Study subject was trials of MR-morphometry in epilepsy. Searching for literature data was conducted in international and national databases between 2017 and 2022 using certain keywords. Final analysis included 36 publications. RESULTS: Currently, MR brain morphometry allows measurement of cortical volume and thickness, surface area and depth of furrows, as well as analysis of cortical tortuosity and fractal changes. In neurosurgical epileptology, MR-morphometry has the greatest diagnostic value in MR-negative epilepsy. This method simplifies preoperative diagnosis and reduces costs. CONCLUSION: Morphometry in neurosurgical epileptology is an additional method for verifying the epileptogenic zone. Automated programs simplify application of this method.

[Relationship between the features of venous drainage of supratentorial arteriovenous malformations and the risk of intracranial hemorrhage]. / Vzaimosvyaz' mezhdu osobennostyami venoznogo drenirovaniya supratentorial'nykh arteriovenoznykh mal'formatsii i riskom razvitiya vnutricherepnogo krovoizliyaniya.

BACKGROUND: Intracranial hemorrhage is the most common complication of cerebral arteriovenous malformations (AVM). In recent years, most studies devoted to the features of AVM functioning consider venous drainage as important factor influencing the rupture of malformation. OBJECTIVE: To review the literature data on the relationship between the features of venous drainage of cerebral arteriovenous malformations and intracranial hemorrhage. MATERIAL AND METHODS: We found 43 studies discussing the features of AVM venous drainage for the period from 1982 to 2020. Most of reports were published between 2005 and 2020. RESULTS: Deep venous drainage and a single drainage vein were the most significant factors influencing the risk of hemorrhage. Venous ectasia, reflux, stenosis, number, length and tortuosity of drainage veins were less important for the risk of AVM rupture. CONCLUSION: Analysis of the features of AVM venous drainage can make it possible to predict the natural course of disease and risk of intracranial hemorrhage. These aspects are essential for neurosurgical treatment.

[Endovascular treatment of aneurysms associated with cerebral arteriovenous malformations]. / Endovaskulyarnoe lechenie anevrizm, assotsiirovannykh s tserebral'nymi arteriovenoznymi mal'formatsiyami.

There are proximal, distal and intranidal AVM-associated aneurysms (G. Redekop, 1998). OBJECTIVE: To evaluate treatment outcomes in 120 patients with AVM-associated aneurysms. MATERIAL AND METHODS: We analyzed treatment outcomes in 639 patients with cerebral AVM who underwent 1992 endovascular procedures between 2010 and 2019. AVM-associated aneurysms were found in 120 (18.8%) cases: 81 (67.5%) patients with 69 proximal and 29 distal aneurysms, 33 (27.5%) AVMs with intranidal aneurysms and 6 (5%) aneurysms without hemodynamic connection with AVM. One hundred and one malformations (16.9%) out of 596 supratentorial AVMs and 19 (44.2%) out of 43 subtentorial AVMs were associated with aneurysms. RESULTS: Intracranial hemorrhage occurred in 349 (53.3%) out of 639 patients with AVM: 97 (80.8%) out of 120 patients with AVM-associated aneurysms and 252 (48.6%) out of 519 ones with AVM and no aneurysms. All 33 patients with intranidal aneurysms in the AVM structure and 18 (94.7%) out of 19 patients with AVM-associated aneurysms and AVM in posterior cranial fossa had intracranial hemorrhage. There were 98 aneurysms in 81 patients with AVM-associated aneurysms. Eighty-nine (90.8%) ones underwent endovascular treatment, 6 (6.1%) patients with proximal aneurysms required microsurgery. Three distal aneurysms were not repaired. Thirty-four aneurysms were embolized with spirals. Embolization with spirals and balloon assistance was performed for 41 aneurysms, spirals with stent-assistance - for 9 aneurysms (including 1 distal MCA aneurysm in hemorrhagic period). Implantation of a flow-diverting stent was performed for 5 aneurysms (1 distal and 4 proximal aneurysms). There were 8 (8.9%) complications after embolization of 89 AVM-associated aneurysms (5 thromboembolic and 3 hemorrhagic events). CONCLUSION: According to our data, intranidal aneurysms require exclusion of the parent AVM segment due to high risk of hemorrhage. Treatment of proximal AVM-associated aneurysms should be carried out prior to AVM embolization. Distal aneurysms do not regress after definitive AVM treatment and should be operated on after total AVM embolization.

[3D modeling for planning of minimally invasive approach to the orbit]. / Ispol'zovanie 3D-modelirovaniya dlya planirovaniya minimal'no invazivnogo dostupa k oblasti orbity. Sluchai iz praktiki i obzor literatury.

OBJECTIVE: To demonstrate own experience in 3D modeling for planning of minimally invasive approach to the orbit and anterior skull base. MATERIAL AND METHODS: A 17-year-old patient admitted to the Department of Pediatric Neurosurgery with complaints of decreased visual acuity of the left eye, lacrimation and exophthalmos. MRI revealed a tumor of the left orbit. We have preoperatively modeled frontoorbital region, anterior skull, as well as eyeball and tumor within the same model. Considering young age and potentially favorable prognosis of disease, we preferred a minimally invasive intervention (microsurgical resection of tumor through minimally invasive frontoorbital access). RESULTS: Total resection of tumor was followed by examination of anterior skull base. There was postoperative regression of visual disturbances, lacrimation and exophthalmos. Sutures were removed after 5 days, and the patient was discharged. CONCLUSION: Minimally invasive frontoorbital access is adequate for approach to the orbit, anterior and middle cranial fossa, adequate resection of orbital tumor and examination of anterior skull base. 3D modeling is an additional preoperative tool to improve the quality of preoperative planning and facilitate intraoperative navigation.

[Endovascular treatment of extracranial dissecting aneurysms of cervical arteries]. / Vnutrisosudistoe lechenie ekstrakranial'nykh dissektsionnykh anevrizm brakhiotsefal'nykh arterii.

BACKGROUND: Dissecting aneurysms of extracranial cervical arteries are a rare vascular pathology. To date, there is no consensus on the choice of optimal surgical approach for these aneurysms. OBJECTIVE: To evaluate the effectiveness of endovascular treatment of various extracranial dissecting aneurysms. MATERIAL AND METHODS: There were 19 patients with 21 extracranial dissecting aneurysms for the period from January 1, 2013 to October 19, 2020. Clinical examination, ultrasound and neuroimaging data were considered to determine surgical intervention. RESULTS: Nineteen patients underwent 20 intravascular interventions: aneurysm embolization with detachable coils with stent-assistance (n=9), flow-diverting stent implantation (n=5), arterial reconstruction with a stent for carotid stenting (n=3), aneurysm embolization with balloon assistance (n=1), aneurysm embolization with detachable coils without assistance (n=2). There were no complications. All patients were discharged without neurological impairment after 1-5 days. Long-term results of control angiography were analyzed within 1-19 months in 12 patients. All aneurysms were completely occluded. Asymptomatic occlusion of flow-diverting stent together with aneurysm occurred in 1 patient with low compliance to antiplatelet therapy. Other 6 patients are scheduled for elective angiography. CONCLUSION: Extracranial dissecting aneurysms of cervical arteries require vigilance due to their rare occurrence and risk of severe complications. In our opinion, intravascular interventions are advisable for these patients as effective and safe procedures.

[Unfavorable outcome of giant vertebral artery aneurysm. Clinical case and literature review]. / Neblagopriyatnyi iskhod techeniya gigantskoi anevrizmy pozvonochnoi arterii. Klinicheskoe nablyudenie i obzor literatury.

OBJECTIVE: To demonstrate the unfavorable natural course and prognosis of giant vertebral artery aneurysm, to analyze the literature, and to conduct a postmortem histopathological study of the features of this disease.

[Andrey Lvovich Polenov - the founder of national traumatology and neurosurgery (by the 150th anniversary)]. / Andrei L'vovich Polenov ­ osnovopolozhnik otechestvennoi travmatologii i neirokhirurgii (k 150-letiyu so dnya rozhdeniya).

April 19, 2021 will mark the 150th anniversary of the birth of Andrei L. Polenov, an outstanding Russian surgeon, scientist, public figure, the founder of traumatology and neurosurgery, the creator of the first scientific and practical schools of traumatology and neurosurgery in our country.

[Endovascular embolization of high-flow arteriovenous fistulae with non-adhesive agents in the structure of cerebral arteriovenous malformations on the background of adenosine-induced cardioplegia]. / Opyt endovaskulyarnoi embolizatsii vysokopotokovykh arteriovenoznykh fistul v strukture tserebral'nykh arteriovenoznykh mal'formatsii neadgezivnymi embolizatami na fone adenozin-indutsirovannoi kardioplegii.

OBJECTIVE: To analyze the initial results of endovascular embolization of cerebral arteriovenous malformations involving high-flow arteriovenous fistulae with non-adhesive agents on the background of cardioplegia. MATERIAL AND METHODS: There were 13 patients who underwent surgery in 2018. Embolization of AVM with non-adhesive agents (ONYX, SQUID) was performed on the background of temporary cardiac arrest achieved by bolus intravenous administration of adenosine triphosphate. CONCLUSION: Adenosine administration in endovascular treatment of AVM with non-adhesive agents is able to improve the safety of surgical intervention and ensure more qualitative embolization.

[Arteriovenous malformations and epileptic seizures in children: risk factors of seizures and efficacy of their control depending on the surgical treatment modality]. / Arteriovenoznye mal'formatsii i épilepticheskie pristupy u detei: faktory riska razvitiia pristupov i éffektivnost' ikh kontrolia v zavisimosti ot metoda khirurgicheskogo lecheniia.

Epileptic seizures are some of the most frequent manifestations of cerebral AVMs in children. Poor control of seizures can significantly affect patients' quality of life. In this case, factors that are associated with the development of seizures and affect the efficacy of their control upon treatment of cerebral AVMs are not well understood. PURPOSE: The purpose of this study was to identify risk factors for the development of epileptic seizures as well as factors associated with a seizure-free outcome of AVM treatment in children. MATERIAL AND METHODS: We analyzed the results of examination and treatment in 89 patients with cerebral AVMs aged 1 to 17 years. RESULTS: Factors associated with the development of epileptic seizures in cerebral AVMs in children included male gender of the child, a large size of AVM and its superficial location, as well as localization of the pathology in the frontal and temporal lobes of the brain and draining varices. Regression of seizures after surgery was more often observed in the case of microsurgical and/or complex surgical treatment and complete exclusion of the AVM as well as in cases of rare attacks and a short course of the disease. CONCLUSION: Complex and microsurgical treatment of AVMs in children provides effective control of epileptic seizures, which is obviously associated with complete exclusion of the AVM and removal of the epileptic focus located near the AVM.

[Methods to assess competence of indirect cerebral revascularization in children]. / Metody otsenki sostoiatel'nosti nepriamoi revaskuliarizatsii golovnogo mozga u detei.

The use of catheterization cerebral angiography (CCA) to assess collateral blood flow through an indirect anastomosis is traumatic for children, uses a high radiation dose, and requires anesthetic care in most cases. AIM: we aimed to compare the capabilities of triplex ultrasound (TU) of vessels, magnetic resonance angiography (MRA), computed tomography angiography (CTA), and CCA in assessing the competence of indirect cerebral revascularization (ICR) in children. MATERIAL AND METHODS: ICR was performed in 18 children in 24 hemispheres (24 operations). The results were evaluated by Matsushima classification-based comparison of the data of preoperative and postoperative clinical examinations, TU of the superficial temporal artery, magnetic resonance imaging (MRI) and computed tomography (CT) of vessels, and selective cerebral angiography. RESULTS: After surgery, improvements in the neurological and neuropsychological status were assessed. Matsushima grade A collaterals were found in 12 (50%) cases, grade B collaterals were present in 3 (13%) cases, grade C collaterals were present in 7 (29%) cases, and grade D collaterals were detected in 1 (4%) case; in 1 (4%) case, the superficial temporal artery was not enhanced. MR angiography visualized 18 (75%) indirect anastomoses, CT angiography revealed 4 indirect anastomoses, and TU visualized 4 indirect anastomoses. Comparison of preoperative and postoperative TU data for the superficial temporal artery revealed significant changes in blood flow in the form of increased rate indices and a decreased resistance index; mean values of indices for each angiographic class of revascularization and significant differences in pre- and postoperative observations were calculated. CONCLUSION: Examination of ICR competence using CCA is necessary in the presence of persistent clinical signs of chronic cerebral circulatory insufficiency, absence of increased blood flow and decreased peripheral resistance in the superficial temporal artery, and lack of anastomosis according to MRA. The most optimal techniques for postoperative examination are MRA with perfusion and diffusion maps and TU.

[Granulomatous inflammation in the bed of resected cerebral cavernoma in a child, caused by a hemostatic agent].

OBJECTIVE: The study presents a clinical observation of foreign body granuloma, which is rare productive inflammation, developed on treatment with a hemostatic material upon removal of cerebral cavernoma. MATERIAL AND METHODS: A 4-year-old boy operated on for left parietal lobe cavernoma was diagnosed with a mass lesion during a follow-up MRI examination 4 months after surgery. The patient was re-operated in connection with suspected abscess formation. The pathological tissue was subjected to the histological and immunohistochemical examination. RESULTS: Inflammation was accompanied by the formation of foreign body granulomas, and, in some areas, had immune nature with signs of focal destructive vasculitis, delayed maturation of the granulation tissue, and disturbance of the current organization and encapsulation processes. It is worth noting that granulomatous inflammation around a hemostatic material in the brain has no specific features during introscopy and mimics an abscess or tumor recurrence. CONCLUSION: The use of hemostatic materials upon resection of cerebral cavernous malformations may cause formation of granuloma mimicking disease relapse or abscess in the long term period. To prevent granulomatous inflammation, removal of a hemostatic material, if possible, from the surgical field is recommended when reliable hemostasis is achieved.

[Specific features of brain tumors and their surgical treatment of first 2 years of life infants].

The authors present a retrospective analysis of results of examination and surgical treatment of 74 infants not older than 24 months with brain tumors of different localization, operated in the same clinic during 15 years. Attention is paid to specific clinical course, character of blastomatous process, surgical strategy and postoperative period in this age category of infants.

[Brain tumors combined with hydrocephalus].

We performed retrospective analysis to find out how severity of hydrocephalus influenced course of the disease in children with malignant brain tumors. Hydrocephalus was discovered in 62% of patients with malignant cerebral tumors but its frequency did not depend on degree of malignancy. Regression of hydrocephalus was obtained in 67.2% of cases after surgical removal of the tumor depending on degree of resection. Hyperproduction and hyperabsorption of CSF were more common in malignant tumors that in benign. Probably one of the leading mechanisms is impaired CSF absorption due to increased protein level and amount of unbound tumor cells in CSF, as well as tumor invasion of basal cisterns. Effectiveness, complications and role of shunting operations in complex treatment of children with malignant brain tumors is investigated. We demonstrated that shunting is indicated as symptomatic treatment when hydrocephalus persists or becomes more severe after tumor removal with restoration of CSF pathways, while conservative treatment is unsuccessful.