[Application of desflurane in anaesthesiology].

Desflurane (Des)--is a modern inhalation anaesthetic available in Russia since August, 2013. Des is a halogenated ether; its chemical structure is 2-difluoromethoxy-1-1-1-2-tetrafluoroethane (C3H2F6O). Special thermocompensated evaporators are used for Des dosing. Low solubility in blood and tissues of an organism causes fast absorption and elimination of Des. Blood/gas distribution ratio of Des is 0.42. Des distinctive properties are high saturated vapor pressure, super short duration of action and average power. Furthermore it is characterized by the minimal metabolism and lack of interaction with soda lime. Des is used for general anesthesia in a cardiac surgery neurosurgery, out-patient surgery, pediatric practice and other areas of surgery. Des has more positive qualities and fewer limitations, than other inhalation anaesthetics (halothane, isoflurane, sevoflurane). High cost of the anaesthetic is compensated by quality and controllability of anaesthesia and reduction of stay time in recovery unit. Fast elimination of the anaesthetic from a body allows reducing a frequency of complications connected with violation of upper airway and hypoxemia, promotes early discontinuation of artificial ventilation, reducing somnolence, earlier restoring a muscular tone in the postoperative period.

[Intracranial and cerebral perfusion pressure in neurosurgical patients during anaesthesia with xenon].

Despite difficulties in providing xenon anaesthesia, xenon still seems to be attractive for neurosurgical procedures. But data upon its effect on intracranial (ICP) and cerebral perfusion pressure (CPP) remains controversial. We monitored ICP and CPP in patients with or without intracranial hypertension during xenon inhalation in different concentrations. Our results suggest that caution should be used while inhaling xenon in high anaesthetic concentration in patients wiith known intracranial hypertension. We also address new possibilities of xenon use, e.g., for sedation in neurosurgery. The study was supported by Russian Fund for Fundamental Research, grant number 13-04-01640.

[Effects of xenon anesthesia on cerebral blood flow in neurosurgical patients without intracranial hypertension].

Among anesthetic agents used in neurosurgery xenon appears to be the most advantageous. It preserves arterial blood pressure, assures rapid recovery and neuroprotection. But the data is lacking on xenon effect upon cerebral blood flow under anesthetic conditions. We measured flow velocity in middle cerebral artery in neurosurgical patients without intracranial hypertension during closed circuit xenon anesthesia comparing propofol and xenon effect in the same patients. In our study xenon didn't seem to induce clinically relevant changes in cerebral blood flow and preserved cerebral vascular reactivity thus proving its safety in patients without intracranial hypertension.

[Patient positioning on the operating table in neurosurgery: sitting or lying].

Efficacy and safety of microvascular decompression of trigeminal nerve depending on the position on the operating table were assessed in 200 neurosurgical patients in retrospective observational study It was shown that efficacy doesn't depend on positioning. Lying position eliminates probability of such complications as postural hypotension, hypotension during surgery, tension pneumocephalus and peripheral nerves injury. Sitting position increases risk of air venous embolism by 25 times. Lying position increases risk of postoperative nasal liquorrhea by 4 times, but eliminates risk of postoperative paresis of trigeminal nerve. It is also decreases risk of corneal reflex reduction by 3 times, hyperpathia by 2 times and paresthesias by 5 times, but increases probability of postoperative hyperesthesia by 4 times. Microvascular decompression of trigeminal nerve in lying position is safer than similar operation in sitting position.

[Coronary artery stents and neurosurgery: choosing the lesser of two evils].

Patients with coronary artery stents are extremely dependent on antiplatelet therapy whose discontinuation may lead to stent thrombosis with major cardiac adverse events. In neurosurgery chronic antiplatelet medications uptake is supposed to be the major factor of postoperative intracranial hematoma associated with poor outcome and high mortality. Thus planning neurosurgical procedure in patients with coronary stents needs a thorough evaluation of all risk factors pondering possible profit and danger. We discuss current recommendations on perioperative management for high risk bleeding surgery in high risk thrombosis patients emphasizing the role of individual approach and multidisciplinary collaboration.

[Prognostic value of D-dimer fibrin level in neurosurgical patients before elective hospitalization].

Deep vein thrombosis and pulmonary embolism in postoperative period are very dangerous complications for patient with any surgical pathology. Frequency of deep vein thrombosis in neurosurgical patient can be up to 25-30%. D-dimer level is considered as one of the most reliable indicator of thrombosis. We measured D-dimer level before hospitalization for elective surgery in 4052 patients with different neurosurgical pathology. It was found clear correlation with elevated D-dimer level and frequency of ultrasound signs of thrombosis. In patients with simultaneous presence of elevated D-dimer level and external signs of varicose veins diagnosis was confirmed by ultrasound in every cases. We consider that D-dimer can be reliable screening method for assessment the risk of thrombosis in neurosurgical patients in preoperative period.

[Blood loss in surgery of brain tumors in infants].

Functional immaturity of all organs and systems result in a high risk of complications in surgery of brain tumors in infants. One of the most serious complications is a massive blood loss and developing on its background severe disorders of hemostasis. In modern series of observations perioperative mortality in these children varies from 13 to 33%. The purpose of this paper--based on an analysis of topography, morphology and features of the operations to determine risk groups of blood loss in surgery of brain tumors in infants and suggest the best options for surgical tactics. When operating blood loss exceed 300% of the calculated blood volume persistent violations of coagulation homeostasis develop, which can lead to uncontrolled bleeding and death on the operating table, or post-operative bleeding. Intraoperative blood loss could be reduced by surgical techniques improvement, as well as by improving of anesthesia. First type includes preoperative embolization of the afferent vessels, careful planning of surgical approach, including using neuronavigation, deep stromal tumor coagulation during debulking, primary coagulation of main feeding blood vessels, two-stage surgery, and optimization of speed of tumor removal. All these methods has reduced the overall operational and post-operative mortality rate from 13 to 5%.

[Intra-arterial injection of verapamil in treatment of cerebral vasospasm in a patient with acute subarachnoid hemorrhage from an aneurysm: case report].

Cerebral vasospasm is a major cause of cerebral ischemia and neurological deficits in patients after SAH from the aneurysm. According to angiorraphy cerebral vasospasm in acute rupture of an aneurysm is detected in 50-70% of cases, and the risk of ischemia on it's background is 19-46%. One of the new trends of treatment of cerebral vasospasm is the intra-arterial injection of calcium channel blockers. The article presents a case of selective intra-arterial injection of verapamil for the treatment of cerebral vasospasm in patient after severe subarachnoid and parenchymal hemorrhage of the internal carotid artery bifurcation aneurysm with a good clinical outcome.

[Management of postoperative analgesia in patients after craniotomy].

In a review paper, an analysis of publications in the world literature on the problem of acute postoperative pain in neurosurgical patients who underwent craniotomy is performed. Is shown that problem of acute postoperative pain in patients after craniotomy was underestimated for a long time. Mistakenly was thought that these patients do not experience any pain in the early postoperative period. Results of recent studies have shown that up to 80% of these patients may experience acute pain in the range from mild to severe. Unarrested postoperative pain could cause a number of serious secondary complications. This article demonstrates basic approaches to the prevention and treatment of acute postoperative pain in neurosurgical patients after craniotomy--first of all, the use of narcotic analgesics, NSAIDs, and other approaches.

[Glioneuronal tumor with neuropil-like islands in a neonate]. / Glioneironal'naia opukhol' s uchastkami neiropilia u rebenka grudnogo vozrasta.

Glioneuronal tumor with neuropil-like islands - GTNI is a rare histopatological subtype of anaplastic astrocytoma. English-language literature contains only 43 observations, among them only 4 observations in children up to 18 years. Neuropil is an eosinophilic stained a cellular foci of tumor tissue. These cells demonstrate less proliferation activity than prevailing glial component, which is characterized by a high degree of atypia - Gr III according to WHO classification. Single reports about verification of the glioneuronal tumor with neuropil-like islands in children are supplemented with an observation of the case with tumor, located in lateral ventricular in infant with the onset of hypertension symptoms at the age of 11 months. The potential for complete removal of these tumors despite its large size and young age of the child is presented. However, the prognosis in infants with GTNI despite completeness of removal and chemotherapy might be extremely unfavorable - in case of intraventricular localization progression in the form of tumor implantation on ventricular ependyma is possible.

[Methodological approaches for assessment of intracranial aneurisms treatment efficiency].

Recently vascular neurosurgery is on stage of comparing of different techniques for intracranial aneurisms treatment. Clinical and randomized studies provide with data that different drugs and techniques have neuroprotective effect, for example haemogenesis growth factors. To introduce any growth factors in practice the research proving the effectiveness of the drug must be carried out. Accurate and complete characteristics of treatment outcomes play the main role in all studies. Terms of outcomes assessment must be characterized and patients must be distributed in order of their condition. The article briefly reviews the problem of comparative assessment of different techniques for intracranial aneurisms treatment.

[Spinal neurosurgical intervention in a patient with end-stage renal disease (ESRD)].

The article presents the description of clinical observation, in which spinal neurosurgical intervention was successfully made in a patient with ESRD, receiving chronic hemodialysis for 20 years. In this context, we discuss the various clinical and tactical aspects of the management of patients with this severe co-pathology: infusion-transfussion therapy, peculiarities of anesthetic management and intra-operation monitoring, diagnostics and correction of hemostasis disorders, hemodialysis organization.

[Application of robotized radiosurgical system CyberKnife for the treatment of neurosurgical patients].

Robotized system for radiosurgery CyberKnife (Accuray Inc., USA) is the first device dedicated and optimized for advanced irradiation during 1-7 fractions (i.e. radiosurgery and hypofractionation). CyberKnife is characterized by elaborate guidance system, high precision of dose delivery, possibility of conformal dose distributions with high gradient of target borderline dose which is most important in proximity of critical structures. The first CyberKnife system in Russia was installed in Burdenko Neurosurgery Institute. The paper presents 2-year experience of treating patients using CyberKnife. From April 2009 till October 2011 896 patients were treated using CyberKnife. Mean age was 48 years. Overall number of sessions was 2626. Radiosurgical procedures were performed in 21.8% of patients. 91% of cases were treated for intracranial lesions. Limited follow-up period in all kinds of pathology demonstrated results consistent with standard fractionation or radiosurgery. The rates of observed complications were also comparable with accepted techniques. CyberKnife system plays significant role in everyday activity of department of radiation therapy. In careful and thorough selection of patients it allows efficient and high-quality treatment of patients with neurosurgical diseases.

[Monitoring of intracranial pressure difference between supra- and infratentorial spaces after posterior fossa tumor removal (case report)].

A clinical example shows that after a neurosurgical operation in posterior fossa there could appear intracranial pressure difference between supra- and infratentorial spaces. This difference develops due to pressure rise in posterior fossa and maintenance of this hypertension postoperatively. Hypertension in posterior fossa and intracranial difference are accompanied by brainstem reactions and temporary neurological disorders. While the pressure difference decreases and ICP in posterior fossa normalizes the neurological symptoms disappear. ICP in supratentorial space not necessarily correlates with ICP in infratentorial space. In some cases it is necessary to measure ICP in infratentorial space after posterior fossa surgery.

[Epilepsy surgery--what is required from anesthesiologist].

The review contains brief description of modem anesthetic approaches used in intractable epilepsy surgery. The authors describe main types of neurosurgery operations for intractable epilepsy, as well as the basic anesthetics and anesthetic plans and their influence on the intraoperative ECoG. Another issue raised is awake craniotomy - an anesthetic method with intraoperative emergence for verbal contact between patient and psychologist. We conclude that epilepsy surgery is one of the neurosurgery fields where anesthesiologist can significantly affect the outcome of the operation.

[Intracranial pressure changes during xenon anesthesia in neurosurgical patients without intracranial hypertention].

Xenon assures rapid awakening and stable hemodynamics, it also has some neuroprotective effect. This is the reason why it may become an anesthetic of choice in neurosurgery. Still there is little and controversial data on its impact upon ICP. This is the first study of xenon effect upon intracranial pressure, cerebral perfusion pressure and cerebrovascular reactivity during xenon anesthesia in neurosurgical patients without intracranial hypertension. We report a slight increase in intracranial and a slight decrease in cerebral perfusion pressure during xenon anesthesia and show that cerebrovascular reactivity is preserved. Thus we conclude that xenon anesthesia is safe for neurosurgical patients without intracranial hypertension.

[Impact of xenon anesthesia on cerebral oxygenation and metabolism in neurosurgical patients].

In recent years the background for xenon anesthesia implementation in neurosurgery has been created. A variety of researches have been conducted though very few of them concerned xenon effect upon cerebral metabolism. We assessed cerebral oxygenation and cerebral metabolism during propofol anesthesia followed by xenon closed circuit anesthesia in neurosurgical patients. Xenon inhalation was marked by higher jugular vein saturation, oxygen content and glucose level and lower arterio-venous difference. We conclude that compared to propofol xenon improves cerebral oxygenation and decreases cerebral metabolism in neurosurgical patients.

[Monitoring the depth of anesthesia in neurosurgical patients].

The study reports the results of monitoring the depth of anesthesia with BIS technology in 456 neurosurgical patients with different neurosurgical pathology: sub- and supratentorial tumors, aneurisms, arteriovenous malformations, spinal pathology, etc. BIS reflects hypnotic state of the brain during anesthesia in almost all the cases, except for bifon-tal surgical approach when sensor placement is impossible. BIS monitoring of the depth of anesthesia is most advantageous in the following cases: epilepsy surgery, spine surgery with neurophysiological monitoring, awake craniotomy, severe cardiovascular pathology, massive blood loss, neurosurgery in pregnant patients.

[Thromboelastography as a method for preoperative assessment of hemostasis state in neurosurgical patients on long term aspirin therapy].

The hemostasis state was assessed by routine tests and TEG in 169 patients on long term aspirin therapy. According to TEG results all the patients were divided into three groups: normo-, hypo- and hypercoagulation. The aspirin therapy was interrupted in normo- and hypercoagulation groups, but the surgery was not postponed. In cases of hypocoagulation the aspirin therapy was also interrupted and the surgery was postponed for 3-5 days until TEG results normalized. Also the frequency of intracranial hemorrhagic complications was analyzed in every group. The results showed that despite the method used the hypocoagulation group had the highest rate of postoperative hemorrhage complications. Thromboelastography enables to assess hemostasis state in neurosurgical patients on long term aspirin therapy promptly and effectively.