[«Burr hole¼ microsurgery for vestibular schwannoma]. / «Burr hole¼ mikrokhirurgiya vestibulyarnykh shvannom.

OBJECTIVE: To evaluate the efficacy and safety of minimally invasive «burr hole¼ microsurgery for vestibular schwannoma. MATERIAL AND METHODS: A retrospective analysis of postoperative outcomes in 50 consecutive patients with vestibular schwannoma was performed. All patients underwent burr hole microsurgery between 2016 and 2020. RESULTS: All patients satisfactorily tolerated surgical treatment. Total resection was carried out in 21 (42%) cases, almost total resection - in 21 (42%) patients (>95% of baseline volume). Subtotal resection was performed in 8 (16%) cases. Mean surgery time was 132 min (range 60-340). Postoperative deterioration of facial nerve function occurred in 20 (40%) patients. Severe dysfunction (House-Brackmann grade V-VI) was observed only in three patients. Other 17 patients had moderate dysfunction of the facial nerve (House-Brackmann grade III-IV). Useful hearing was preserved in 6 (50%) out of 12 patients with preoperative useful hearing. CONCLUSION: Minimally invasive burr hole microsurgery is an effective method for vestibular schwannoma. Moreover, the proposed technique reduces surgery time due to simpler craniotomy and wound closure.

[Primary juvenile nasal angiofibroma in a 38 year-old male (case report)]. / Pervichno vyiavlennaia iunosheskaia angiofibroma osnovaniia cherepa u muzhchiny 38 let (klinicheskoe nabliudenie).

Juvenile nasal angiofibroma (JNA) is a benign, fibro-vascular, locally aggressive tumor with invasive growth patterns and high probability of recurrence. JNA present exclusively in adolescent boys between 9 and 19 years of age, total about 0.05% of head and neck tumors. 143 patients with JNA had been treated surgically from 2002 to August 2018 at N.N. Burdenko National Medical Research Center for Neurosurgery. All patients (primary and recurrences) were males of the age 7-38 years (16.1 [11.3; 19] years). The age of patients with primary JNA was less than 18-year old, of the exception of presenting case. There are more and more publications about case reports and successful treatment series of JNA. However, after detailed review the literature we revealed some kind of confusion: there are case reports of JNA in women and elderly people, JNA in patients with some systemic diseases, JNA with different places of origin and different morphological structure. In this paper we present a very rare case of 38 year-old male with pure primary JNA, accidentally diagnosed on CT and pathologically proven after endoscopic removal. This case confirms the possibility of detecting the JNA in adult men and explains why proper diagnosis of angiofibromas is necessary. The unique case and the literature review are presented.

[Application of intraoperative electromagnetic frameless navigation in transcranial and endoscopic neurosurgical interventions]. / Primenenie bezramnoi sistemy intraoperatsionnoi élektromagnitnoi navigatsii pri transkranial'nykh i éndoskopicheskikh neirokhirurgicheskikh vmeshatel'stvakh.

The paper summarizes the experience in using a system of electromagnetic intraoperative frameless navigation in various neurosurgical pathologies of the brain. The electromagnetic navigation technique was used for 102 operations in 98 patients, including 36 transnasal endoscopic interventions. There were no intraoprtative and postoperative complications associated with the use of the system. In the process of using the system, factors influencing the accuracy of navigation and requiring additional control by the surgeon were identified. PURPOSE: The study purpose was to evaluate the use of electromagnetic navigation in surgical treatment of patients with various brain lesions. MATERIAL AND METHODS: The system of electromagnetic navigation was used for 102 operations in 98 patients (42 males and 56 females, including 18 children; median age, 34.8 years (min, 2.2 years; max, 69 years)) in the period from December 2012 to December 2016. In 36 patients, the system was used for endoscopic interventions. In 19 patients, electromagnetic navigation was used in combination with neurophysiological monitoring. RESULTS: In our series of cases, the frameless electromagnetic navigation system was used in 66 transcranial operations. The mean error of navigation was 1.9±0.5 mm. In 5 cases, we used the data of preoperative functional MRI (fMRI) and tractography for navigation. At the same time, in all 7 operations with simultaneous direct stimulation of the cortex, there was interference and significant high-frequency noise, which distorted the electrophysiological data. A navigation error of more than 3 mm was associated with the use of neuroimaging data with an increment of more than 3 mm, image artifacts from the head locks, high rate of patient registration, inconsequence of touching points on the patient's head, and unsatisfactory fixation to the skin or subsequent displacement of a non-invasive localizer of the patient. In none of the cases, there was a significant effect of standard metal surgical tools (clamps, tweezers, aspirators) located near the patient's head on the navigation system. In two cases, the use of massive retractors located near the patient's localizer caused noise in the localizer and navigation errors of more than 10 mm due to significant distortions of the electromagnetic field. Thirty-six transnasal endoscopic interventions were performed using the electromagnetic frameless navigation system. The mean navigation error was 2.5±0.8 mm. CONCLUSION: In general, electromagnetic navigation is an accurate, safe, and effective technique that can be used in surgical treatment of patients with various brain lesions. The mean navigation error in our series of cases was 1.9±0.5 mm for transcranial surgery and 2.5±0.8 mm for endoscopic surgery. Electromagnetic navigation can be used for different, both transcranial and endoscopic, neurosurgical interventions. Electromagnetic navigation is most convenient for interventions that do not require fixation of the patient's head, in particular for CSF shunting procedures, drainage of various space-occupying lesions (cysts, hematomas, and abscesses), and optimization of the size and selection of options for craniotomy. In repeated interventions, disruption of the normal anatomical relationships and landmarks necessitates application of neuronavigation systems in almost mandatory manner. The use of electromagnetic navigation does not limit application of the entire range of necessary intraoperative neurophysiological examinations at appropriate surgical stages. Succession in application of neuronavigation should be used to get adequate test results.

[Endoscopic endonasal diagnosis and treatment of skull base meningoencephalocele]. / Éndoskopicheskaia éndonazal'naia diagnostika i lechenie meningoéntsefalotsele osnovaniia cherepa.

PURPOSE: The study purpose was to determine the successful outcome rate of endoscopic endonasal reconstruction of skull base CSF fistulas with removal of meningocele as well as analyze disease relapses. The second purpose of the study was to describe the treatment outcomes, depending on the type, location, and size of meningocele as well as on a technique used to reconstruct the skull base defect. MATERIAL AND METHODS: Three hundred and eleven patients diagnosed with cerebrospinal fluid (CSF) rhinorrhea who underwent surgery at the Burdenko Neurosurgical Institute in the period between 2007 and 2014 were retrospectively analyzed. Meningocele was detected in 141 (45.3%) of all patients with CSF rhinorrhea. The diagnosis was made before surgery and verified during endoscopic endonasal reconstructive closure of skull base defects. Therefore, the analysis group included all cases of meningocele and meningoencephalocele verified during surgery. The study analyzed the gender, age of surgery, follow-up period, comorbidities, use of lumbar drainage, etiology of the defect, localization, type of reconstructive material, complications, and disease relapses. We defined the efficacy of endoscopic endonasal meningocele resection with fistula reconstruction as the absence of signs of CSF rhinorrhea and a hernia sac based on the data of control CT and endoscopy performed in the late postoperative period. The follow-up period ranged from 1 month to 5 years. RESULTS: All patients underwent endoscopic endonasal reconstruction of the skull base defect. The treatment efficacy was 110 (78%) patients for primary surgery and 26 (84%) patients for repeated surgery. CONCLUSION: Endoscopic endonasal surgery is a safe, effective, and minimally invasive technique for treatment of meningocele and meningoencephalocele, which enables resection of a hernia sac and reconstruction of dura mater and skull base defects.