[Spontaneous dural CSF fistula as a cause of intracranial hypotension syndrome. Case report and literature review]. / Spontannaya dural'naya likvornaya fistula kak prichina sindroma vnutricherepnoi gipotenzii. Sluchai iz praktiki i obzor literatury.

Typical symptoms of spontaneous intracranial hypotension syndrome are severe headache, weakness, dizziness and inability to stay upright for a long time. Most often, this syndrome occurs due to CSF fistula in spinal space. Pathophysiology and diagnosis of this disease are poorly known for neurologists and neurosurgeons that can complicate timely surgical care. In case of correct diagnosis, we can identify the exact location of CSF fistula in 90% of cases. Treatment eliminates symptoms of intracranial hypotension and provides functional recovery. The purpose of this article is to describe the diagnostic algorithm and successful microsurgical treatment of a patient with spinal dural CSF fistula Th3-Th4 through posterolateral transdural approach.

[Degenerative lumbar spine stenosis: minimally invasive microsurgical methods of treatment]. / Degenerativnyi stenoz poyasnichnogo otdela pozvonochnika: kharakteristika minimal'no invazivnykh mikrokhirurgicheskikh metodov lecheniya.

Degenerative lumbar spine stenosis is one of the main causes of chronic pain and radiculopathy in advanced age people. Along with increase in average life expectancy, degenerative lumbar spine stenosis becomes the most common indication for spinal surgery. There is still no consensus regarding the most optimal surgical approach due to the variety of modern surgical methods. In recent years, minimally invasive spinal surgery has become a more advisable alternative to open surgery due to its advanced technical features combined with less soft tissue damage, lower risk of complications and shorter postoperative recovery.

[Intraoperative computed tomography and modern navigation in surgical treatment of spine and spinal cord diseases]. / Opyt primeneniya intraoperatsionnogo spiral'nogo komp'yuternogo tomografa i sovremennoi sistemy navigatsii v khirurgicheskom lechenii zabolevanii pozvonochnika i spinnogo mozga.

Surgical treatment of spine and spinal cord diseases is one of important objectives in modern neurosurgery. Patient safety is a priority in spine and spinal cord surgery. Intraoperative imaging ensures efficacy and safe surgery with and without stabilization, preoperative marking, control of decompression and correct implant placement. Surgical C-arms and intraoperative cone-beam CT scanners are the most widespread in everyday practice. The latest achievement was intraoperative spiral computed tomography. C-arms and CT scanners with intraoperative navigation increase the efficiency and safety of surgical interventions.

[Visual fluorescence combined with laser spectroscopy in surgery for intramedullary spinal cord tumors]. / Vizual'naya fluorestsentsiya v kombinatsii s lazernoi spektroskopiei v khirurgii spinal'nykh intramedullyarnykh opukholei.

BACKGROUND: Surgical treatment of intramedullary spinal cord tumors is aimed at total resection of tumor with maximum preservation of neurological and functional status. In some cases, intramedullary tumors have unclear dissection plane or gliosis zone. This area is not a tumor and does not require resection. However, it is difficult to distinguish visually intact spinal cord tissue and tumor at the last surgical stages. Thus, we evaluated the effectiveness of fluorescence combined with laser spectroscopy in surgical treatment of intramedullary spinal cord tumors. OBJECTIVE: To determine the effectiveness of visual fluorescence combined with laser spectroscopy in surgery for intramedullary spinal cord tumors. MATERIAL AND METHODS: There were 850 patients with intramedullary spinal cord tumors for the period 2001-2019. In 35 cases, intraoperative fluoroscopy with laser spectroscopy were used. All patients underwent a comprehensive pre- and postoperative clinical and instrumental examination (general and neurological status, McCormick grade, spinal cord MRI). Carl Zeiss OPMI Pentero microscope with a fluorescent module was used for intraoperative fluorescence diagnosis. A domestic preparation 5-ALA «ALASENS¼ (State Research Center NIOPIK, Moscow, Russia) was used for induction of visible fluorescence. Laser spectroscopy was carried out using a LESA-01-BIOSPEK spectrum analyzer. Morphological analysis of intramedullary spinal cord tumors was performed in the neuromorphology laboratory of the Burdenko Neurosurgery Center. RESULTS: Intramedullary anaplastic ependymoma and astrocytoma, as well as conventional ependymoma were characterized by the highest index of 5-ALA accumulation. Intramedullary hemangioblastoma and cavernoma do not accumulate 5-aminolevulinic acid due to morphological structure of these tumors. In particular, there are no cells capable of capturing and processing 5-ALA in these tumors. Sensitivity of visual fluorescence combined with laser spectroscopy varies from 0% to 100% depending on the histological type of tumor: hemangiogblastoma and cavernoma - 0%, low-grade astrocytoma - 70%, high-grade astrocytoma - 80%, ependymoma - 92%, anaplastic ependymoma 100%. Dissection plane is absent in anaplastic ependymoma, high-grade astrocytoma. We often observed gliosis during resection of ependymoma. This tissue is not a part of tumor. Intraoperative metabolic navigation with neurophysiological monitoring are advisable for total tumor resection in case of unclear dissection plane and peritumoral gliosis. CONCLUSION: Visual fluorescence combined with laser spectroscopy is a perspective method for intraoperative imaging of tumor remnants and total resection of intramedullary spinal cord tumors with minimum risk of neurological impairment.

Rare Cases of IDH1 Mutations in Spinal Cord Astrocytomas.

A low occurrence rate of spinal cord gliomas (4.3% of primary and glial CNS tumors) and the associated difficulties in building statistically significant cohorts of patients considerably slow down the development of effective approaches to the treatment of spinal cord tumors compared to brain tumors. Despite our extensive knowledge regarding IDH mutations in intracranial tumors, mutations of this gene in spinal cord astrocytomas remain poorly understood. In this study, we report on five cases of identified mutations in the IDH1 gene in spinal cord astrocytoma cells, two of which are unique, as they have never been previously described in CNS gliomas.

Surgical Simulation of a Posttraumatic Spinal Cord Glial Scar in Rats.

We developed and verified an original, minimally invasive method for surgical simulation of a posttraumatic spinal cord glial scar in rats. The model is intended for use as a biological platform for testing the stimulation of regenerative processes in the central nervous system. Unification of the model enables one to achieve versatility both for implantation techniques and for the development of system-action approaches. Faced with a standard structural defect of the spinal cord, researchers will have the unique opportunity to test in vivo promising methods for spinal function recovery in the posttraumatic period. We developed anesthetic support, surgical tactics, and a set of rehabilitation measures for the chronic postoperative period. Experimental exposure effects were preliminarily assessed in vivo using a standard technique for recording the motor activity of rats in the postoperative period of spinal cord injury. Our final conclusions were drawn based on an analysis of histological sections of the rat spinal cord glial scar in three mutually perpendicular planes.

Molecular Biomarkers of Brain and Spinal Cord Astrocytomas.

Spinal cord astrocytomas are rare diseases of the central nervous system. The localization of these tumors and their infiltrative growth complicate their surgical resection, increase the risk of postoperative complications, and require more careful use of radio- and chemotherapy. The information on the genetic mutations associated with the onset and development of astrocytomas provides a more accurate neoplasm diagnosis and classification. In some cases, it also allows one to determine the optimal methods for treating the neoplasm, as well as to predict the treatment outcomes and the risks of relapse. To date, a number of molecular markers that are associated with brain astrocytomas and possess prognostic value have been identified and described. Due to the significantly lower incidence of spinal cord astrocytomas, the data on similar markers are much more sparse and are presented with a lesser degree of systematization. However, due to the retrospective studies of clinical material that have been actively conducted abroad in recent years, the formation of statistically significant genetic landscapes for various types of tumors, including intradural spinal cord tumors, has begun. In this regard, the purpose of this review is to analyze and systematize the information on the most significant genetic mutations associated with various types of astrocytomas, as well as discuss the prospects for using the corresponding molecular markers for diagnostic and prognostic purposes.

[Treatment of malignant peripheral nerve sheath tumors: case reports and a literature review]. / Lechenie zlokachestvennykh opukholei obolochek perifericheskikh nervov: sluchai iz praktiki i obzor literatury.

Malignant peripheral nerve sheath tumors (MPNSTs) are soft tissue sarcomas that develop from peripheral nerve sheath cells (T. Hirose, B.W. Scheithauer). These tumors are characterized by aggressive growth with an unfavorable outcome and may develop de novo or through malignant transformation of schwannomas, neurofibromas, or ganglioneuromas. MPNSTs are characterized by a rapid course and a poor prognosis. In this article, we reported cases of patients with malignant peripheral nerve tumors of the brachial plexus trunks and spinal localization.

[Resection of a giant sacral schwannoma: case report and literature review]. / Udalenie gigantskoi nevrinomy v oblasti kresttsa: sluchai iz praktiki i obzor literatury.

Neurogenic sacral tumors are extremely rare. In most reported cases, this pathology was associated with neurofibromatosis. Sacral tumors manifest themselves at the stage when the neoplasm volume becomes giant, but these manifestations usually go unnoticed for the patient. Surgical approach to the sacral region is extremely challenging; intimate proximity of tumor capsule to vital organs, vessels, and nerves makes radical surgical treatment of these neoplasms rather difficult. A case report of radical resection of a schwannoma that was destroying the sacrum and continued to grow after radiotherapy is presented in this article.

[Complications of surgical treatment of sacral tumors]. / Oslozhneniia khirurgicheskogo lecheniia opukholei kresttsovoi lokalizatsii.

Sacral tumors are a group of neoplasms heterogeneous in the histological type, malignancy, and growth pattern, but with common localization. Surgical treatment of these tumors is associated with the risk of major and minor complications, both during and after surgery. Usually, any surgery aimed at removing tumors in the sacrum or sacral region is associated with the need for reconstruction of bones and/or soft tissues to provide conditions for normal wound healing and the possibility of activating the patient. AIM: The study aim was to analyze complications associated with surgery for sacral tumors. MATERIAL AND METHODS: The study is based on the experience of surgical treatment of 57 patients with the diagnosis of sacral tumor. The patients underwent 60 surgical interventions related to treatment of the underlying pathology and complications of surgical treatment. Major and minor complications developed in 37 (68%) operated patients. A total of 47 different complications were recorded. In 6 patients, complications in the early postoperative period required additional surgery. CONCLUSION: Surgical treatment of sacral tumors is associated with a high risk of complications. Despite the potential risk of major complications, sacrectomy for primary, or potentially aggressive, or malignant neurogenic tumors of the sacrum is necessary to improve local control and survival of patients.

[Intraoperative video-angiography in surgery for spinal intramedullary cavernous malformations: first experience of its application at the Burdenko Neurosurgical Center]. / Intraoperatsionnaia videoangiografiia v khirurgii intramedulliarnykh kavernoznykh mal'formatsii spinnogo mozga: pervyi opyt ispol'zovaniia v FGAU 'Natsional'nyi meditsinskii issledovatel'skii tsentr neirokhirurgii im. akad. N.N. Burdenko'.

Spinal intramedullary cavernous malformations are a rare vascular pathology of the central nervous system. They account for 3-5% of spinal cord diseases. The clinical picture in patients with cavernous malformations varies from an asymptomatic course to gross neurological deficit in the case of bleeding from a malformation. Due to the lack of reliable methods for predicting the development of bleeding, the need for surgical treatment of asymptomatic patients remains a relevant and open topic for discussion. The goal of surgical treatment of cavernous malformations is to minimize the risk of repeated hemorrhages and gross neurological deficits in patients. Intraoperative indocyanine green video angiography is a promising technique for intraoperative visualization of the size and adherence area of a cavernous malformation to the spinal cord tissue. This increases the radicality of cavernous malformation resection and minimizes intraoperative risks for the patient.

[Surgical treatment of intramedullary-extramedullary ependymomas. Two clinical cases and a literature review]. / Khirurgicheskoe lechenie intra-ékstramedulliarnykh épendimom. Dva klinicheskikh nabliudeniia i obzor literatury.

Ependymoma is a central nervous system tumor that grows from ependymal cells lining the cerebral ventricles, central canal of the spinal cord, and filum terminale. Regardless of the histological type of ependymomas, they rarely have exophytic growth. Because of an extremely low occurrence rate of this phenomenon, we present two clinical cases of patients with classical intramedullary ependymomas (Grade II) having an extramedullary component. MATERIAL AND METHODS: The paper presents two clinical cases of patients with intramedullary-extramedullary ependymomas of the spinal cord. The surgical technique is described. After surgical treatment, the performance status of patients remained unchanged. CONCLUSION: Radical removal of complex ependymomas provides conditions for long-term disease-free survival and further neurological recovery.

[Management of neurogenic tumors of the sacrum and sacral area]. / Taktika lecheniia neirogennykh opukholei kresttsa i kresttsovoi oblasti.

Tumors of the sacrum rarely occur in routine practice. Due to the absence of pathognomonic symptoms, the diagnosis often becomes apparent at a late disease stage. In this case, the treatment approach depends on the degree of tumor malignancy, growth pattern and location, and relationship between the tumor and the nervous structures, major vessels, and pelvic bones. OBJECTIVE: Analysis of the overall and relapse-free survival of patients with neurogenic tumors of the sacrum. MATERIAL AND METHODS: In this study, we analyzed the treatment outcomes in 27 patients with neurogenic sacral tumors who underwent surgery at the Burdenko Neurosurgical Institute. RESULTS: The median survival time of patients with neurogenic tumors was 72 months; the shortest survival time was observed in a group of neurogenic sarcomas, with the mean survival time being 30 months. Malignant tumors of the peripheral nerves recurred in 100% of cases. CONCLUSION: Surgical treatment of neurogenic tumors of the sacrum reduces pain, but does not lead to regression of the neurological symptoms caused by compression of the sacral plexus roots. Patients with malignant tumors of the sacrum should undergo partial or complete sacrectomy. In this case, the choice of treatment strategy should be based on assessment of the functional status, tumor histology, and somatic features of the patient.

[Percutaneous endoscopic discectomy in the treatment of patients with degenerative diseases of the lumbosacral spine]. / Opyt primeneniia perkutannoi éndoskopicheskoi diskéktomii v lechenii patsientov s degenerativnymi zabolevaniiami poiasnichno-kresttsovogo otdela pozvonochnika.

Modern surgery uses a variety of treatments for spine pathology. Endoscopic techniques have become particularly popular across the world over the past decade. In this article, we summarize our experience and analyze the immediate and long-term results of surgical treatment of lumbar disc herniation using a percutaneous fully endoscopic technique for removing the herniated intervertebral disc, which is new for Russian medical practice. OBJECTIVE: to evaluate the efficacy of percutaneous endoscopic discectomy in the treatment of herniated lumbar discs in patients with radicular pain syndrome. MATERIAL AND METHODS: We conducted a cohort retrospective study that included 69 patients who underwent herniated disc removal using the percutaneous endoscopic technique. Surgery was performed through two approaches: the intralaminar approach was used in 44 patients, and the transforaminal approach was used in 25 patients. To assess the efficacy of surgery, we used a visual analogue scale (VAS) of pain: the intensity of local pain (VAS1) and the intensity of radicular pain (VAS2). Changes in the quality of life and ability to work were assessed by using the Oswestry scale; patient satisfaction with treatment was assessed by using the MacNab scale. RESULTS: The mean follow-up period after surgery was 24 months. An analysis of changes in the pain syndrome (VAS1 and VAS2) before surgery and in the early postoperative period demonstrated a significant regression of pain regardless of the approach type (r=0.25). Patients' survey (MacNab scale) in the long-term postoperative period revealed no unsatisfactory results; excellent, good, and satisfactory results were observed in 21 (30%), 32 (46%), and 16 (24%) patients, respectively. CONCLUSION: Percutaneous endoscopic discectomy is an effective surgical treatment for degenerative diseases of the lumbosacral spine, providing excellent and good treatment outcomes in most operated patients.

[Results of surgical treatment for lumbar spine segmental instability]. / Rezul'taty khirurgicheskogo lecheniia nestabil'nosti pozvonochno-dvigatel'nogo segmenta poiasnichnogo otdela pozvonochnika.

AIM: To perform a comparative analysis of outcomes in patients with lumbar spine segmental instability who underwent surgical treatment using transforaminal lumbar interbody fusion (TLIF) and direct lateral interbody fusion (DLIF) techniques. MATERIAL AND METHODS: The multicenter study involved 209 patients who underwent surgery for lumbar spine segmental instability. Long-term outcomes (up to 2 years) were studied in 134 patients: patients of the first group (98 patients) underwent traditional transforaminal lumbar interbody fusion (TLIF) and transpedicular stabilization of vertebral segments; patients of the second group (36 patients) underwent direct lateral interbody fusion (DLIF) in combination with transpedicular stabilization of the lumbar vertebral segments. We used standard checkpoints for monitoring the patients' condition: before surgery, at discharge, at 3, 6 and, 9 months, and at 1 and 2 years after surgery. To follow-up the patients, we used the Visual Analogue Scale, Oswestry Disability Index, and Goal Attainment Scaling. RESULTS: A comparative analysis of the two interbody fusion techniques was enabled by the developed Vertebrologic Registry profile (http://spineregistry.ru/Register_treatment.php) that was designed for entering data of Russian and foreign experts to analyze clinical characteristics, evaluate outcomes, and follow-up patients with degenerative lumbosacral spine diseases. In both groups of patients, a significant decrease in the pain intensity in the lumbar spine and lower extremities (VAS) occurred in the immediate postoperative period, which persisted in the long-term period. There were no differences in the disability level (Oswestry index) in both groups of patients (p<0.05). An analysis of treatment goal attainments one year after surgery revealed the best result in patients of the second group who underwent DLIF. CONCLUSIONS: 1. Indirect decompression using direct lateral interbody fusion (DLIF) minimizes the risks of intraoperative injury to the dura mater and neural structures. Kawabata class I outcomes (good) were achieved in 89% of patients who underwent direct lateral spinal fusion (DLIF) and in 81% of patients who underwent transforaminal interbody stabilization in combination with transpedicular fixation.

[PREDICTING, POSSIBLE WAYS TO REDUCE AND CORRECTION OF MASSIVE INTRAOPERATIVE BLOOD LOSS IN SPINAL TUMOR SURGERY].

The paper discusses the problem ofpredicting, prevention and therapy of massive intraoperative blood loss in patients with metastasis in spine and spinal cord. We analyze 60 surgical cases in last 14 years in our clinic. Amount of blood loss was more that 80% of total blood volume in each case (from 2.5 to 17 liters). Preoperative selective angiography data on intensity of tumor blood supply were essential for blood loss prediction. Simultaneous embolization oftumor during angiography dramatically reduced intraoperative blood loss. Combination of blood saving techniques (preoperative autodonation, acute normovolemic hemodilution and intraoperative cell salvage) led to effective compensation of blood volume deficit and minimizing of allogenic blood transfusion. Plasma-derived and recombinant factors were effective in management of hemostatic disorders associated with massive blood loss.

[The use of intraoperative neuroimaging tools and a navigation system in surgical treatment of primary and metastatic tumors of the spine].

INTRODUCTION: Surgical treatment of spinal tumors is associated with a high risk of intraoperative complications, including injury to the spinal cord, its roots, and large vessels both during tumor resection and at the stabilization stage during implantation of pedicular or corporal screws. The use of intraoperative neuroimaging tools and a navigation system in surgical treatment of oncological diseases of the spine enables identifying the location and extension of a tumor lesion directly in the operating room, which provides control of the resection area and the possibility of the spine stabilization under disturbed anatomy conditions when bone density is altered by the osteolytic process or systemic changes. Also, the risk of injury to the major blood vessels is reduced. MATERIAL AND METHODS: Surgical treatment of 156 patients with primary and metastatic tumors of the spine was performed at the Burdenko Neurosurgical Institute in the period from 2002 to December 2014. Twelve patients underwent diagnostic intervention (transcutaneous biopsy), and 35 patients underwent surgery using intraoperative CT and a navigation systems. The indication for biopsy using both CT and the navigation system was the presence of a spinal tumor not verified by a pathomorphological examination. An O-arm intraoperative computed tomography scanner and a Medtronic's StealthStation S7 Navigation System were used in all cases. CONCLUSION: The use of both CT and the navigation system provides high quality treatment and significantly reduces radiation exposure to the medical personnel and patient. The possibility of intraoperative identification of the location and extension of a tumor in bone tissue facilitates adequate tumor resection within the intact surgical margin, with the surrounding vessels and neurological structures being under real-time control.

[Extradural spinal cord hemangioblastoma (a case report and literature review)]. / Ekstradural'naya gemangioblastoma spinnogo mozga (sluchai iz praktiki i obzor literatury).

Hemangioblastoma is a rare CNS vascular tumor that develops sporadically and can also be associated with von Hippel-Lindau disease. Hemangioblastomas account for 2-6% of all spinal cord tumors and are ranked third in the structure of intramedullary space-occupying lesions of the spinal cord. For the first time in our practice, we observed a dumbbell paravertebral hemangioblastoma. The international literature reports only 3 cases of the tumor with this growth type.

[Modern treatments for degenerative disc diseases of the lumbosacral spine. A literature review]. / Sovremennye metody lecheniia degenerativnykh zabolevanii mezhpozvonkovogo diska. Obzor literatury.

Many researchers consider degenerative diseases of the spine as a pandemic of the XXIst century. Herniated intervertebral discs of the lumbosacral spine occur in 61% of patients with degenerative spine diseases. Of these, 15% of patients have herniated discs at the LII-LIII level, 10% of patients at the LIII-LIV level, and 40% of patients at the LIV-LV and LV-SI levels. A high cost of conservative treatment of degenerative spine disease symptoms and its low efficacy in reducing the intensity and duration of pain necessitate the development of new methods of surgical treatment. In this paper, we analyze the literature data on minimally invasive spine surgery and demonstrate the main advantages of percutaneous endoscopic surgical techniques.

[Compatibility of cells of the nervous system with structured biodegradable chitosan-based hydrogel matrices].

Hydrogel matrices for cell cultivation have been generated by two-photon laser polymerization of unsaturated chitosan derivatives and methacrylated hyaluronic acid. The adhesive and toxic properties of the matrices have been assessed, and the matrices have been shown to have a good compatibility with primary hippocampal cell cultures. The formation of morphologically normal neural networks by cells of the nervous system cultured on the surface of hydrogel matrices has been observed. The metabolic status of dissociated hippocampal cells cultured on the matrices was similar to that of the control cultures, as shown by the results of MTT reductase activity assay. Thus, matrices based on unsaturated polysaccharide derivatives crosslinked by laser irradiation showed good compatibility with differentiated cells of the nervous system and considerable potential for use in neurotransplantation.