The study objective is an assessment of long-term results of cerebral revascularization performed in the acute period of subarachnoid hemorrhage due to rupture of cerebral aneurysms.

Materials and methods. This cross-sectional study includes 74 patients, operated in N.V. Sklifosovsky Research Institute for Emergency Medicine in the acute period of aneurysmal subarachnoid hemorrhage. Patients were divided into two groups. The first group contained patients with EC—IC bypass performed in the acute period of aneurysmal subarachnoid hemorrhage. The Control group contained patients without bypass. In the long-term period, 11 patients were examined. Computed tomography of cerebral vessels, duplex ultrasound examination of the aortic arch, brachiocephalic arteries and intracranial vessels, transcranial Doppler ultrasonography with a breathing function test, single-photon emission computed tomography of the brain followed by stress test with acetazolamide, Modified Renkin Scale, Mini-Mental State Examination, Montreal Cognitive Assessment, Index Bartel, The Hospital Anxiety and Depression Scale, Holms-Rahe were performed. For descriptive results, a mathematical model was used.

Results. The best treatment outcomes in severe patients with subarachnoid hemorrhage and cerebral ischemia were observed when performing simultaneous clipping of the aneurysm and EC-IC bypass (57.1 % versus 41.0 %) there was no statistically significant difference in outcomes. EC-IC bypass functioned in 37.5 % of cases. The rate and acceleration of the fall in volumetric blood flow and the passage of blood from the aortic bulb to the cerebral arterioles affect the perfusion values in the region of the brain concerned. Evaluation of long-term results of simultaneous interventions revealed persistent disturbances in the regulation of cerebral blood flow at the microcirculatory level. Patients with EC-IC bypass had a higher level of cognitive function and stress potential.

Conclusion. The results of this study showed us the necessity for a comprehensive exploration of cerebral blood flow.

The study objective is to analyze long-term clinical and radiological outcomes in patients after performing total lumbar disc replacement at the level of the lumbosacral junction.

Materials and methods. A multicenter retrospective observational cohort study was performed. The study included medical records of patients who underwent total lumbar disc replacement at the level of the lumbosacral junction. Both clinical and instrumental parameters were assessed. According to the eligibility criteria, 93 patients were included in the study (38 men, 55 women, mean age 39.9 ± 7.5 years). The average postoperative observation period for the respondents was 33.4 ± 9.5 months.

Results. The severity of pain in the lumbar spine on a visual analogue scale significantly decreased (from 7.3 ± 2.5 to 1.9 ± 2.2 cm, p <0.001). The indicators of the quality of life according to the Oswestry Disability Index and according to the Short Form-36 scale (including the mental and physical components) of the studied group of respondents significantly improved (from 43.4 ± 17.6 to 18.9 ± 16.0 %, р <0.001 and from 30.8 ± 8.5 to 52.3 ± 12.4 %, p <0.001, respectively). From the 12^th month of observation of the respondents, a significant decrease in the values of the range of motions of the operated segment was noted from 5.3 ± 3.2° to 4.1 ± 3.6° (p <0.009). Also, from the 12th month of postoperative observation, a slight decrease in the values of the range of motions of the adjacent segment from 8.6 ± 4.1° to 7.8 ± 3.8° (p >0.05) was verified. The value of global lumbar lordosis after the installation of a lumbar intervertebral disc prosthesis at the level of the lumbosacral junction significantly increased from 49.1 ± 4.8° to 55.6 ± 5.5° (p <0.001). Intervertebral disc prostheses with a lordotic angle of 10° reliably positively correlate with an increase in the values of segmental lordosis, in contrast to implants with an angle of 6° (r_S = 0.86, p = 0.04). The severity of pain in the lumbar spine according to visual analogue scale and the range of motion of the operated segment has a significant negative correlation in the late periods of postoperative follow-up (24 and 36 months, r_S = -0.74, p = 0.015).

Conclusion. The total lumbar disc replacement technique is an effective method of surgical treatment of patients with degenerative diseases of the intervertebral discs of the lumbosacral spine, including at the level of the lumbosacral junction.

Introduction. Every year, there is an increase in the number of operations performed using personalized cranioplasts, which are made with additive 3D printing technologies. They allow surgical intervention, taking into account the characteristics of the shape of the patient's skull. This is especially important when closing large and complex defects extending from the cranial vault to the bones of the facial skeleton. One of the innovative applications of additive technologies in cranioplasty is the creation of implants, preformed based on individual 3D-printed models. However, no preliminary estimates of the results of treatment of patients using the traditional methods of cranial implants and individualized modeling methods were found in the available literary sources.

The study objective is to compare the results of treatment using cranioplasts, preformed based on individual 3D-printed skull models and using traditional intraoperative modeling.

Materials and methods. A study of 50 patients with post-craniotomy defects of the skull. All patients have undergone cranioplasty. Depending on the technique of individualization of the cranial implants, patients were divided into 2 groups: 1st - using individual 3D-printed models (n = 32), 2^nd - traditional intraoperative modeling (n = 18).

Results. Statistically, the groups differed significantly in terms of the duration of the intraoperative stage of cranioplasty, postoperative and total hospital stay, indicators of symmetry and financial costs. No differences were found in the duration of the preoperative hospital stay, the number of implant fixation points, the volume of intraoperative blood loss and the quality of life according to the SF-36. The first group (6.25 %) in comparison with the second (16.7 %) had a smaller number of postoperative complications.

Conclusion. Modern 3D printing technologies recreate bone models based on patients' individual characteristics, thereby providing time for careful planning of the operation, even at the outpatient stage. The results of the study showed that the usage of cranioplasts preformed with 3D-printed models provides precise closure of post-craniotomy defects, better restoration of the skull contours, and a significant reduction in the duration of the cranioplasty stage. The use of the technology does not lead to a significant increase in the cost of treatment using traditional intraoperative modeling.

The study objective is to investigate the features of distal aneurysms of the middle cerebral artery and to evaluate the results of their surgical treatment.

Materials and methods. From 01/01/2000 to 12/31/2019 at the N.V. Sklifosovsky Research Institute of Emergency Medicine, 37 patients with distal SMA aneurysms were operated (21 women, 16 men, the average age of 48 y. o). SMA aneurysms were classified by their localization according to the classification of H. Gibo. The aneurysms of the M2 segment of the MCA were encountered more often (56.8 %). 28 aneurysms had a saccular structure, 9 (24.3 %) had a fusiform. The size of the saccular aneurysms ranged from 1.4 to 34.0 mm. More than 65 % of patients had aneurysms of 7 mm or less.

Results. The surgical access was selected depending on the location of the MCA aneurysm. The pterional transsylvian access is used more often, less often - with aneurysms of the M4-segment, convexital trepanation. The reconstructive clipping of the distal SMA aneurysm was performed in 22 (59.4 %) cases, trapping and/or excision in 15 (40.5 %) cases. After the deconstructive intervention, revascularization was performed on 6 (16 %) patients.

Conclusion. Distal aneurysms of the middle cerebral artery are a rare pathology that requires an individual approach -contact Doppler ultrasound or intraoperative angiography, intraoperative neuromonitoring, as well as, if necessary, the use of revascularization methods. To optimize surgical access, it is preferable to use neuronavigation.

Introduction. Surgery has traditionally remained the main treatment for tumors of the cerebellopontine cistern but is associated with high risks of dysfunction of the cranial nerves. Radiosurgery is usually performed both as an adjuvant treatment and as an independent option.

The study objective is to assess the safety of routine use of radiosurgery to preserve facial nerve function in the treatment of tumors of different origins located in the cerebellopontine cistern.

Materials and methods. Since March 2018 to March 2020 there were 145 patients with tumors of cerebellopontine cistern (CPC) at the Center for High-Precision Radiology. Vestibilar schwannomas were detected in 116 (80 %) patients, in 37 cases - relapses or remains after surgery. The 22 patients had meningiomas, 6 after open surgery (WHO I). Trigeminal schwannomas - in 3 patients, facial schwannomas - in 2, jugular schwannomas - in 1 and metastasis of prostate cancer - in 1. 31 patients had facial paresis of different degrees after previous surgery. Among non-operated patients, facial paresis before radiosurgery was observed in only 1 patient. Radiosurgery was performed using the Leksell Gamma Knife Perfexion, the mean marginal dose was 12.2 Gy (11-15 Gy), the mean tumor volume was 3.98 cm³ (0.06-17.47 cm³).

Results. Follow-up was performed in 85 patients. The mean follow-up was 359.3 days (91-776), the median follow-up was 367 days. Reduction of the tumor volume was detected in 27 patients, stabilization of the process in 15. The average decrease was 23.9 % (95 % CI 16.8-31.0 %). Transient postirradiation increase was observed in 30 patients only in the group of schwannomas and mean tumor volume increase was 53.7 % (95 % CI 38.5-68.9 %). In patients with previous surgery there were not cases of decline or regression facial paresis. Among patients who had not been operated on before radiosurgery, only in 1 case was the development of facial paresis (House-Brackman III) 5 months after irradiation, which amounted to 1.8 %. It should be especially noted that facial nerve function remained unchanged (House-Brackman I) in both patients with facial schwannomas. Also, not a single case of hemifacial spasm was identified.

Conclusion. Radiosurgery of CPC tumors with a marginal dose from 12 to 15 Gy has a high degree of safety in relation to the facial nerve. This makes it possible to justify radiosurgery as alternative to traditional neurosurgical interventions.

The study objective is to evaluate feasibility and effectiveness of decompressive craniectomy (DC) for treatment оf supratentorial hypertensive intracerebral hematomas (ICH).

Materials and methods. Between 1996 to 2019, 97 patients with supratentorial hypertensive ICHs underwent surgical treatment. DC was performed in 50 patients (primary - in 41, secondary - in 9). Putaminal hematomas were diagnosed in 30 patients, subcortical - in 20. The comparison group consisted of 47 patients, of which 20 had osteoplastic craniotomy (OPC) with microsurgical removal of ICH, and 27 had endoscopic aspiration (EA). The performed DCa were treated as unjustified (decreased brain dislocation without prolapse of the brain substance into the trepanation defect), ineffective (preservation of brain dislocation and absence of prolapse of the brain substance into the trepanation defect, as well as small size of the trepanation hole) and effective (prolapse of the brain substance into the trepanation defect and regression of transverse brain dislocation).

Results. DC was effective only in 22 (44 %) patients (13 - primary, 9 - secondary). Among patients with subcortical ICH, mortality rate after DC was equal to that after OPC and EA. Among patients with putaminal ICH, the mortality rate after DC was significantly higher than after OPC and EA. Among the patients who underwent primary EA and delayed DC (due to recurrent ICH), postoperative mortality rate was significantly higher than among the patients who underwent repeated EA of recurrent ICH. However, there were no fatal outcomes among patients who underwent delayed DC due to increased edema and transverse dislocation of the brain without recurrent ICH.

Conclusion. In the surgical treatment of supratentorial hypertensive ICH, decompressive effect of DC was achieved only in 44 % of patients. Open removal of putaminal hematomas in combination with DC was unjustified, mortality rate was 66 %. Primary DC with removal of ICH is indicated in patients with subcortical hematomas with a volume >50 cm³ , with transverse dislocation >7 mm, deep deafness or sopor. Delayed DC, regardless of the location of ICH, is recommended in case of increased edema and transverse dislocation of the brain in patients without recurrent hemorrhage.

The objective is to demonstrate the effectiveness of the vascular decompression with videoendoscopy in the treatment of classical glossopharyngeal nerve neuralgia by a clinical case and to summarize the literature data on this subject. Clinical case. In February 2020, a 56-year-old patient with a clinical picture of glossopharyngeal nerve neuralgia was admitted to the Research Clinical Center of Specialized Medical Care and Medical Technologies. The pain syndrome bothered about 3 years, constantly took carbamazepine at a dose of 1200 mg per day, amitriptyline 75 mg per day, clonazepam 2 mg per day without effect. After further examination and differential diagnosis of causal neuralgia of the glossopharyngeal nerve, a neurovascular conflict appeared between the glossopharyngeal nerve, the posterior inferior cerebellar and vertebral arteries. A good postoperative clinical result was obtained. An analysis of the available scientific literature on this problem is carried out.

Results. After performing vascular decompression of the root of the glossopharyngeal and vagus nerves, pain completely regressed (BNI - I, VAS - 0). 6 months after surgery, there is no pain, the patient does not receive drug therapy. In the course of the analysis of available literature, the effectiveness of vascular decompression in the treatment of patients with classical neuralgia reaches 98 %.

Conclusion. Given the low incidence of glossopharyngeal neuralgia, the correct diagnosis and the choice of an appropriate treatment method determine the outcome of the disease. The performed operation in the volume of vascular decompression of the glossopharyngeal nerve root with the use of videoendoscopy allowed to completely stop the pain syndrome.

The objective is to present the clinical experience of using the pConus stent-like device in the treatment of complex bifurcation aneurysms.

Clinical cases. A 64-year-old patient was admitted with complaints of periodic headache without loss of consciousness and an increase in focal symptoms. Saccular aneurysms of the anterior communicating artery and the left superior cerebellar artery were found without signs of subarachnoid hemorrhage. For occlusion of the aneurysm of the left superior cerebellar artery (dimensions 7.4 х 5.3 mm, neck width 5.0 mm, facing left and up, body/neck ratio 1.48, the branch of the artery branched off from the neck), a pConus device (crown diameter 8 mm) was used with micro-coils.

A 61-year-old patient was admitted with complaints of headache in the occipital region, accompanied by repeated vomiting and an increase in blood pressure to 200/110 mm Hg. Subarachnoid hemorrhage and a saccular aneurysm of the basilar artery bifurcation (facing up, anteriorly and somewhat to the left, measuring 4.9 x 3.4 mm, neck width 3.1 mm, dome/neck ratio 1.1) were revealed. A pConus device was used for micro-coils occlusion (4-25-6 mm).

In the postoperative period, both patients did not experience an increase in focal neurological symptoms. Control angiography after 6 months confirmed stable occlusion, all major vessels were passable.

Conclusion. In the described cases, there were no technical problems during the installation and implantation of the device. The use of the pConus device in the treatment of complex bifurcation aneurysms technically simplifies surgical intervention, since it does not require catheterization of the efferent vessels of the aneurysm.

The objective is to present a clinical case of successful treatment of a patient with recurrent spondylitis at the cervical level.

Clinical case. A 65-year-old patient was diagnosed with purulent spondylodiscitis at the level of C₆-C₇ vertebrae with the epidural and paravertebral abscesses and spinal cord compression. Emergency left colotomy, paravertebral abscess dissection, corporectomy of the C₆ vertebra, abscess removal, anterior spondylodesis with bone autograft and titanium plate were performed. Massive antibacterial therapy was prescribed. After the operation, the volume of movement in the left limbs was restored, and on the 15^th day after the operation, the patient was discharged. On the 36^th day after discharge, she was hospitalized again with hematuria. A recurrence of suppuration in the area of the operation and phlegmon of both feet was revealed. Revision of the surgical wound and rehabilitation of the purulent focus on the neck, surgical intervention for phlegmon were performed. In purulent foci, Staphylococcus aureus was verified, which is sensitive to the main antibacterial drugs. Antibacterial therapy was continued, then, after changing the microflora in the wound, other antibiotics were prescribed. There was a pain in the area of the left spinal root C₅. The connection of the fistula course with the titanium plate, the increase of pathological kyphosis at the level of the overlying vertebrae was found. The wound was examined, the titanium plate was removed, and the halo device was applied to correct the pathological kyphosis. After the operation, the radicular pain syndrome regressed, and the axis of the cervical spine was restored. After 1 month, the posterior combined fixation of the cervical spine at the C₃-Th₇ level was performed, and the halo device was dismantled. After 6 months, the patient was stopped wearing the Philadelphia neck collar, no recurrence of suppuration was observed, and a complete regression of neurological disorders was noted. After 1 year, a complete bone block is preserved between the C₄-C₇ vertebrae.

Conclusion. The presented clinical case clearly illustrates the complexity of managing patients with inflammatory diseases of the cervical spine. Currently, there is no single treatment strategy for patients with spondylitis.

Transcranial surgery of skull base meningiomas currently remains the main method of treatment. Transnasal removal is possible in a number of cases, but it is associated with the risk of postoperative CSF-leak as a result of insolvency of the reconstruction of the skull base defect. Minimally invasive (keyhole) accesses provide a tumor overview comparable to standard accesses in most cases. The anterior-medial part of the anterior cranial fossa and the olfactory fossa is not accessible to the direct view from the minipterional craniotomy. The use of angular endoscopic optics in combination with additional resection or thinning of the bones in the orbital roof provides an overview sufficient to remove the tumor, but manipulations in this area require the use of specific tools. Aspirators, dissectors and coagulators should have bends of different expressions. The application of the described technique is advisable only in certain specially selected cases.

Fractures of the thoracic and lumbar spine are the main volume of injuries in the surgical practice of a neurosurgeon. Classification of injuries is important for standardizing the description of vertebral fractures and collecting statistical data. Important classification parameters are completeness, reliability, and reproducibility. In this paper, a detailed description and illustration of the most significant classifications of injuries of the thoracic and lumbar spine is carried out.

Introduction. Neurosurgery trainees are finding it increasingly difficult to obtain operative experience as the main surgeon in aneurysm procedure. Good quality cadaver dissection opportunities are also not widely available for neurosurgery residents. Simulation is emerging as a useful training aid for neurosurgery. Surgical treatment of cerebral aneurysms requires specialized skills development and proficient use of microsurgical instruments. Furthermore, any advance in neurosurgical training methods is of potential value to both neurosurgeons and patients.

The study objective is to introduce a 3D aneurysm clipping training model to enhance skill acquisition and development.

Materials and methods. The brain model is made using a 3D printed resin mold. The mold is filled with silicone Ecoflex 00–10 and mix with Silc Pig pigment additives to replicate the color and consistency of brain tissue. Dura is made from quick drying silicone paste with grey dye. The blood vessels are made from a silicone 3D printed mold of a magnetic resonance angiography. Liquid with paprika oleoresin (E160c) dye is used to simulate blood and is pumped through the vessels to simulate pulsatile motion.

Results and conclusion. These models offer an alternative method to train residents and preoperative planning. They are affordable and easy to recreate and hence can standardize training in multiple centers. With advancing technology, 3D technology is becoming an import part of medical education.

In 2021, the 150^th anniversary of the founder of the national neurosurgery Andrey Lvovich Polenov is celebrated. The article describes the first years of his independent professional life.