[Keyhole surgery for giant basal brain tumors. Theoretical explanation with an example of trans-eyebrow subraorbital approach]. / Aktual'nost' keyhole-dostupov v khirurgii gigantskikh opukholei osnovaniya golovnogo mozga. Teoreticheskoe obosnovanie na primere chrezbrovnogo supraorbital'nogo dostupa.

BACKGROUND: Improvement of modern neurosurgical technology has given rise to keyhole surgery for a wide range of pathologies. Supraorbital trans-eyebrow approach has been described in detail for small tumors of anterior cranial fossa and suprasellar neoplasms. Can we use this small and less traumatic approach for a more complex tumor extending beyond the suprasellar region? OBJECTIVE: To analyze own experience of surgical treatment of large and giant parasellar tumors via supraorbital approach, to identify the principles of such operations, indications and possible limitations. MATERIAL AND METHODS: There were 58 resections of parasellar tumors via mini-supraorbital approach had been performed between 2016 and 2021 at the 2nd pediatric neurosurgical department. We selected 42 patients with large and giant tumors extending beyond the chiasmal-sellar zone and causing occlusive hydrocephalus (mean volume 44.2 cm3). Preoperative status of patients, postoperative clinical data and logistics of in-hospital treatment were analyzed. RESULTS: Total resection was performed in all cases. No redo surgeries or revisions were required. There were no cases of wound infection, CSF leakage and damage to large vessels. CONCLUSION: We standardized planning of surgeries for large neoplasms considering available knowledge about the nature of diseases, analysis of clinical and X-ray data, goals and objectives of surgery. The reader is offered a theoretical substantiation of applicability of keyhole surgery for chiasmal-sellar tumors on the example of well-known mini-supraorbital approach. We gave certain advices on planning such operations and illustrated clinical examples.

[Lessons learnt from 101 hemispheric pediatric epilepsy surgeries part ii: pitfalls and complications]. / Uroki 101 gemisferotomii u detei s polusharnoi simptomaticheskoi epilepsiei. Chast' II: oslozhneniya i oshibki.

OBJECTIVE: To evaluate the spectrum of pitfalls and complications after hemisherotomy basing on a retrospective study of a large consecutive pediatric cohort of patients from a single institution. MATERIAL AND METHODS: One hundred and one patients (med. age - 43 months) with refractory seizures underwent hemispherotomy. Developmental pathology was the anatomical substrate of disorder in 42 patients. The infantile post-stroke scarring and gliosis was the origin of epilepsy in the majority of 43 cases with acquired etiology. The progressive pathology (RE, S-W and TS) was the etiology in the rest of children (16 cases). The lateral periinsular technique was used to isolate the sick hemisphere in 55 patients; the vertical parasagittal approach was employed in 46 cases. Median perioperative blood loss constituted 10.5 ml/kg, but was markedly larger in kids with hemimegaly (52.8 ml/kg); 57 patients needed hemotransfusion during surgery. Median length of stay in ICU was 14.7 hours, and the length of stay in the hospital until discharge - 6.5 days. Eight patients underwent second-look surgery to complete sectioning of undercut commissural fibers. FU is known in 91 patients (med. length - 1.5 years). RESULTS: Major surgical complications with serious hemorrhage and/or surgery induced life-threatening events developed in 7 patients (one of them has died on the 5th day post-surgery for the causes of brain edema and uncontrolled hyponatremia). Various early and late infectious complications were noted in 4 cases. Ten patients experienced new not anticipated but temporary neurological deficit. Nine patients needed shunting for the causes of hydrocephalus within several first months post-hemispherotomy. Early seizure onset was associated with probability of all complications in general (p=0.02), and developmental etiology - with intraoperative bleeding and hemorrhagic complications (p=0.03). CONCLUSION: Children with developmental etiology, particularly those with hemimegalencephaly, are most challengeable in terms of perioperative hemorrhage and serious complications. Patients with relapse or persisting seizures should be evaluated for the possibility of incomplete hemispheric isolation and have good chances to become SF by re-doing hemispherotomy.

[Lessons learnt from 101 hemispherotomies in children with symptomatic epilepsy. Part I: seizure outcome]. / Uroki 101 gemisferotomii u detei s polusharnoi simptomaticheskoi epilepsiei. Chast' I. Iskhody lecheniya pristupov.

OBJECTIVE: To evaluate variables that may predict the outcome after hemispherotomy basing on a retrospective study of a large consecutive pediatric cohort of patients from a single institution. MATERIAL AND METHODS: One hundred and one patients with refractory seizures and variable decline in development (n=78) underwent hemispherotomy (med. age - 43 months, med. epilepsy history - 30 months). Developmental pathology was the anatomical substrate of disorder in 42 patients, while the infantile post-stroke scarring and gliosis was its origin in the majority of 43 cases with acquired etiology. The progressive pathology (the Rasmussen encephalitis, Sturge-Weber angiomatosis and tuberous sclerosis) was the etiology in 16 children. Left-sided hemisphere was impaired in 54 cases; some contralateral anatomical and potentially epileptogenic MRI-abnormalities were noted also in «healthy¼ hemisphere in » of all cases. Eight patients needed second surgery to complete sectioning of undercut commissural fibers. FU is known in 91 patients (med. - 1.5 years) and 73 of them were free of seizures (80.2%), but only 30 of 40 patients with FU > 2 years were still SF (75%). All but one of re-do hemispherotomies were successful. AED-treatment was discontinued in 46 cases and tapered in other 27 patients. Up to 90% of kids demonstrated some improvement in behavior and cognition. RESULTS AND CONCLUSION: Developmental pathology, infantile spasms and younger age onset of seizures are negative predictors for achievement of SF-status (p<0.05). Neither bilateral epileptic EEG-signs, nor MRI-abnormalities in «healthy¼ hemisphere had any relation to outcome, but focal seizure onset was associated positively with further SF-status (p = 0.03). Kids with multiple lobe unilateral CD do somewhat worse than their counterparts with hemimegalencephaly and acquired etiology. Post-hemispherotomy hemiparesis (either new or worsening of already existed one) has no relation either to the age at surgery, or to the age onset (p = 0.41). Children with left-sided lesions were less successful in every neurodevelopmental domain except maintaining expressive language. Patients with relapse or persisting seizures have good chances to become SF by re-doing hemispherotomy and should be evaluated for the possibly incomplete hemispheric isolation.

[Surgical treatment of epilepsy in children with focal cortical dysplasia]. / Khirurgicheskoe lechenie epilepsii u detei s fokal'noi kortikal'noi displaziei.

OBJECTIVE: Surgery is the first-line treatment option in children with FCD and refractory epilepsy, but the rate of success and patient numbers who became free of seizures vary widely from series to series. STUDY AIMS: To elicit variables affecting the outcome and predicting achievement of the long-term seizure-free status. MATERIAL AND METHODS: One hundred sixty-nine children with cortical dysplasia and DR-epilepsy underwent surgery Preoperative evaluation included prolonged video-EEG and MRI (in all patients) and neuropsychological testing when possible. Fourteen patients underwent invasive EEG, fMRI and MEG were used also in some cases. Including 27 repeat procedures the list of overall 196 surgeries performed consists of: cortectomy (lesionectomy with or without adjacent epileptogenic cortices) ­ in 116 cases; lobectomy ­ in 46; and various disconnective procedures ­ in 34 patients. Almost routinely employed intraoperative ECOG (134 surgeries) was combined with stimulation and/or SSEP in 47 cases to map eloquent cortex (with CST-tracking in some). A new permanent and not anticipated neurological deficit developed post-surgery in 5 cases (2,5%). Patients were follow-upped using video-EEG and MRI and FU which lasts more than 2 years (median ­ 3 years) is known in 56 cases. Thirty-two children were free of seizures at the last check (57,2% rate of Engel IA). A list of variables regarding patients' demography, seizure type, lesion pathology and localization, and those related to surgery and its extent were evaluated to figure out anyone associated with favorable outcome. RESULTS: Both Type II FCDs and their anatomically complete excision are positive predictors for favorable outcome and achievement of SF-status (p<0,05). Residual epileptic activity on immediate post-resection ECOG do not affect the outcome. CONCLUSION: Patients with Type II FCD, particularly with Type IIb malformations are the best candidates for curative surgery, including cases with lesions in brain eloquent areas. Kids with Type I FCD have much less chances to become free of seizures when attempting focal cortectomy. However, some of them with early onset catastrophic epilepsies may benefit from larger surgeries using lobectomy or various disconnections.

[Perimedullary arteriovenous fistula. Case report and literature review]. / Perimedullyarnaya arteriovenoznaya fistula. Klinicheskoe nablyudenie i obzor literatury.

Arteriovenous fistula is a common vascular abnormality of spinal cord and meninges. This disease is more common in young men. Clinical manifestation includes progressive sensitive and motor disorders. However, acute symptoms including impaired consciousness, head or back pain are also possible. The authors describe a rare case. A 15-year-old boy experienced acute depression of consciousness accompanied by headache, vomiting, weakness in the upper limbs and sensitive disorders. The patient was hospitalized to the intensive care unit and examined for subarachnoid hemorrhage. MRI of the head and cervical spine and direct invasive angiography were performed. Perimedullary AVF of cervical spinal cord was diagnosed. Complete clinical regression was observed within a month. Microsurgical removal of AVF was performed in scheduled fashion. Postoperative follow-up period was over 6 months.

[Radicalness and complications of repeated surgery for malignant neuroepithelial tumors of the posterior cranial fossa in children]. / Radikal'nost' i oslozhneniia povtornykh khirurgicheskikh vmeshatel'stv pri zlokachestvennykh neiroépitelial'nykh opukholiakh zadnei cherepnoi iamki u detei.

Treatment of primary malignant neuroepithelial tumors of the posterior cranial fossa (PCF) in childhood includes surgical resection, radiation therapy (RT), and chemotherapy (CT). The radicalness of surgery is one of the most important prognostic factors of survival. Despite the significant advances in treatment, many of these tumors recur. Today, oncologists are increasingly recommending repeated surgery for recurrent malignant neuroepithelial tumors of the PCF to achieve gross total resection (GTR). Patients undergo this surgery after RT and palliative CT, which may increase surgical risks. OBJECTIVE: The study objective was to assess the resection extent of recurrent malignant neuroepithelial tumors of the PCF in children as well as the risk and structure of postoperative complications. MATERIAL AND METHODS: The prospective study included 50 patients under the age of 18 who underwent surgery for recurrent malignant neuroepithelial tumors of the PCF at the Neurosurgical Institute (NSI) in the period between 2002 and June 2015. Anaplastic ependymomas were present in 37 patients, and medulloblastomas were detected in 13 patients. A total of 58 repeated surgeries were performed. RESULTS: GTR was achieved in 53 (91.4%) cases, near total resection (NTR) was achieved in 2 (3.4%) cases, and subtotal resection (STR) was achieved in 3 (5.2%) cases. The mean bed-day after surgery was 12 (4-47) days, and the mean critical care stay was 3.2 (0-23) days. Seven patients required tracheostomy; meningitis developed in 3 patients; liquorrhea occurred in 2 cases. Ventriculoperitoneal shunting was used in 8 (13.8%) cases. One (1.7%) patient died in the early postoperative period. CONCLUSION: Our results demonstrate that resection of recurrent malignant neuroepithelial tumors in children can be performed with high radicalness (90%) and acceptable risks.

[Implantation of VPS in the early postoperative period following removal of posterior cranial fossa tumors in children]. / Neobkhodimost' implantatsii VPSh v rannem posleoperatsionnom periode posle udaleniia opukholei zadnei cherepnoi iamki u detei.

One of the main manifestations of posterior cranial fossa (PCF) tumors is the development of hydrocephalus (HC) symptoms that in most cases are the reason for examination and diagnosis [1, 2]. According to the literature, the rate of shunt surgery after removal of PCF tumors in the children's population is 18-40% [3-9]. Hydrocephalus remaining after removal of PCF tumor and requiring further treatment is called persistent hydrocephalus. The above figures are based on the treatment outcomes in children, which were obtained as early as in the 1990s. Given these facts, we conducted a modern study to assess the risk of persistence/development of persistent hydrocephalus in children after removal of posterior cranial fossa tumors and to explore factors affecting this risk. MATERIAL AND METHODS: We performed a retrospective analysis of the treatment outcomes in 155 children operated on at the Burdenko Neurosurgical Institute between 2012 and 2014. All children were operated on by a single surgeon. Factors, such as the patient age, histological pattern of tumor, and primary/repeated surgery, were analyzed. RESULTS: A total of 13 (8.4%) patients needed shunt surgery. An analysis demonstrated no need for shunt surgery in children with piloid astrocytomas. In children with medulloblastoma, the need for a permanent shunt occurred in 5 (9.1%) cases; all these children were older than 3 years. A group of anaplastic ependymoma included 23 children; of these, 13 children were older than 3 years, and 10 children were under the age of 3 years. Five (21.7%) patients required shunt surgery. Shunting was needed in 3 children from group 4. In one case, a child younger than 3 years of age who was operated on for a dermoid cyst of the PCF, and in 2 children older than 3 years of age who were operated on for ganglioastroscytoma and atypical teratoid-rhabdoid tumor (ATRT). CONCLUSION: At present, the risk of persistent hydrocephalus in children after removal of PCF tumors is lower than that reported in the literature. In our study, it was 8.4%. The age of children under 3 years and repeated operations do not statistically significantly increase the risk of persistent hydrocephalus. Only tumor histology is statistically significant: the highest risk of the need for implantation of VPS was found in the group with anaplastic ependymomas, and the minimal risk was in the group of piloid astrocytomas.