[Evidence-based medicine: opportunities of the Propensity Score Matching (PSM) method in eliminating selection bias in retrospective neurosurgical studies]. / Dokazatel'naia meditsina: vozmozhnost' ispol'zovaniia metoda podbora bol'nykh po indeksu sootvetstviia (PSM) dlia ustraneniia sistematicheskoi oshibki otbora v retrospektivnykh neirokhirurgicheskikh issledovaniiakh.

To date, a large amount of retrospectively collected data about treatment of neurosurgical pathology have been accumulated. Modern methods of medical statistics are necessary for correct interpretation of the data. The article purpose is to demonstrate application of one of the modern methods, Propensity Score Matching (PSM), in neurosurgery. The use of PSM avoids misinterpretation of retrospectively collected data and obviates errors in planning further prospective studies. For the past 10 years, the number of published international PSM-based studies has increased more than 10-fold, with the number of articles by Russian authors accounting for less than 0.2%. In line with the tendencies of international studies, application of PSM in analysis of retrospectively collected data will enable testing of a number of hypotheses and correct planning of prospective randomized studies.

[Surgical treatment of cerebral aneurysms in the Russian Federation]. / Khirurgicheskoe lechenie tserebral'nykh anevrizm v Rossiiskoi Federatsii.

OBJECTIVE: The objective of this study was to evaluate the results of surgical treatment of cerebral aneurysms in the Russian Federation. MATERIAL AND METHODS: We analyzed performance indicators in neurosurgical departments of regional and federal health institutions of the Russian Federation for 2017. The results of surgical treatment of cerebral aneurysms (CAs) were analyzed in 19 regional vascular centers (RVCs) in several federal districts and in 3 federal centers (FCs) with the most dynamically developing vascular neurosurgery and smoothly running system of statistical data processing. RESULTS: The study included 3160 patients hospitalized to 22 medical institutions in 2017. Of these, 1808 patients were treated in RVCs, and 1352 patients were treated in FCs. We analyzed factors affecting the treatment outcome in CA patients. We identified features of CA treatment in clinics with a different amount of surgical intervention. CONCLUSION: An increase in the surgical activity in centers and simultaneous development of microsurgical and endovascular treatments for cerebral aneurysms reduce postoperative mortality. Due to the presence of a RVC network in the Russian Federation, many patients could receive necessary specialized treatment. The number of operations for cerebral aneurysms has increased 6-fold for the past 10 years.

[An experience of neurophysiological monitoring in neurosurgery]. / Opyt primeneniia neirofiziologicheskogo monitoringa pri neirokhirurgicheskikh operatsiiakh.

AIM: To evaluate the efficacy of neuromonitoring methods in prevention of postoperative neurological complications and estimation of predictive power of intraoperative changes in monitored characteristics. MATERIAL AND METHODS: Retrospective study examined 240 patients, operated in the years 2014-2015 using intraoperative neurophysiological monitoring. One hundred and seventy-three patients suffered from hemispheric lesions and 67 had lesions located in or near the brainstem. Somatosensory evoked potentials (SSEP) were monitored in 152 cases, visual in 32, brainstem acoustic in 22, transcranial motor in 36; stimulation mapping of motor cortex was performed in 69 surgeries, and cranial nerves identification in 27. EEG was recorded in 7 patients, and 3 of them were woke up during the surgery for speech mapping. RESULTS: The sensitivity of the SSEP in motor dysfunction detection was low (33%), while the specificity was relatively high (82%). These characteristics for visual and motor evoked potentials were close to 100% provided that the parameters of anesthesia met the corresponding requirements. The most effective methods in respect of prevention of postoperative dysfunctions were the stimulation mapping of functionally significant areas (motor and speech) and motor pathways mapping. CONCLUSION: Intraoperative neuromonitoring reduces a number of neurological complications after neurosurgical operations. The SSEP method is not sensitive enough in surgeries that could affect motor centers and/or pathways, and multimodal monitoring combining SSEP and motor responses recording during transcranial and/or direct electrical brain stimulation. Successful monitoring requires highly coordinated actions between neurophysiologists, neurosurgeons and anesthesiologists.

[Transarterial and transvenous embolization of deep binodal arteriovenous malformation of the brain].

INTRODUCTION: The multimodal approach to treatment of arteriovenous malformations yields good results. However, small and deep malformations still pose a big problem for surgeons. Transvenous embolization was designed as an alternative for the cases when endovascular treatment is required and conventional transarterial embolization is not available. CASE STUDY: A 41-year-old patient with binodal malformation in the subcortical nuclei of the left hemisphere of the brain, which had previously become a source of massive parenchymal ventricular hemorrhage, was operated on using the transarterial and, for the first time in our clinic, transvenous approaches. Transarterial embolization of the thalamic node of malformation was performed as the first step. After 6 months, transvenous embolization of the hypothalamic node of malformations was performed as the second step. Successful operation was ensured by using a stable coaxial guiding catheter system with the maximum distal approach and intranidal positioning of a microcatheter with detachable distal portion upon temporary occlusion of afferent vessels of the malformations using a balloon catheter. The operation resulted in total thrombosis of the malformation. No perioperative complications were observed. Control examination in 6 months did not reveal recanalization of the malformation. CONCLUSION: The transvenous approach can be successfully used in endovascular treatment of small and deep arteriovenous malformations with a single drainage vein, which are inaccessible to direct surgery. It can also be used when radiosurgery is associated with a high risk in cases where transarterial embolization is infeasible.