[Surgical treatment of cervical paragangliomas]. / Khirurgicheskoe lechenie paragangliom shei.

AIM: To present own experience in surgical treatment of cervical paragangliomas. MATERIAL AND METHODS: 9 patients with cervical paragangliomas were enrolled. Endovascular embolization of supplying vessels followed by maximally radical surgery and subsequent carotid arteries repair involved into tumoral process reduces the risk of complications. RESULTS: The most careful attitude to caudal group of cranial nerves adjacent or involved into neoplasm allows to minimize postoperative neurological complications.

[The use of high-flow extracranial-intracranial artery bypass in pathology of the cerebral and brachiocephalic arteries: technical features and surgical outcomes]. / Ispol'zovanie metoda obkhodnogo vysokopotochnogo ékstra-intrakranial'nogo arterial'nogo shuntirovaniia pri patologii tserebral'nykh i brakhiotsefal'nykh arteriĭ: tekhnicheskie osobennosti i rezul'taty operatsiĭ.

BACKGROUND: Poor outcomes of surgical treatment for complex cerebral aneurysms due to the development of cerebral ischemia were the cause to use cerebral revascularization surgery for this pathology. OBJECTIVE: the study objective was to master a high-flow extracranial-intracranial (EC-IC) artery bypass technique and evaluate its application in surgical treatment of complex and giant cerebral aneurysms as well as complex lesions of the brachiocephalic arteries. MATERIAL AND METHODS: Fifty two patients underwent high-flow IC-EC bypass surgery; of these, 34 patients had complex cerebral aneurysms, and 18 patients had complex stenotic occlusive lesions of the brachiocephalic arteries. After bypass placement, the patients with aneurysms underwent different variants of aneurysm exclusion (trapping or proximal clipping/ligation of the parent artery). All patients underwent follow-up studies of the bypass function and clinical condition in the early postoperative period and 6 and 12 months after surgery. RESULTS: High-flow IC-EC bypass surgery is routinely used in clinical practice of the Novosibirsk Federal Center of Neurosurgery. Fifty one out of the 52 patients were followed-up in a range of 4 to 56 months. According to the direct or CT angiography data, bypasses functioned in 51 (98.1%) patients in the early and long-term postoperative periods. The clinical efficacy (no ischemic changes and improved cerebral perfusion) of high-flow IC-EC bypasses was demonstrated in 31 (91.2%) of 34 patients with aneurysms and in 17 (94.4%) of 18 patients with complex lesions of the brachiocephalic arteries. The total number of surgical complications was 8 (15.4%) cases: 7 complications occurred in patients with aneurysms, and 1 complication developed in a patient with bilateral ICA occlusion. Of these, ischemic complications developed in 4 (7.7%) cases, hemorrhagic complications occurred in 2 (3.8%) cases, and cranial nerve complications were found in 2 (3.8%) cases. One (1.9%) female patient with a giant aneurysm died from hemispheric stroke due to insufficient blood flow through the bypass. CONCLUSION: Implementation of a large number of surgeries enabled improvement of the technique and clarification of the prerequisites for preoperative examination, intraoperative control, and postoperative management of patients. A low mortalits rate suggests this technique for use in clinical practice. The surgery is indicated for the treatment of giant aneurysms of the petrous, cavernous, and clinoid segments of the ICA. In the case of giant supraclinoid aneurysms, the surgery may be combined with removal of thrombotic masses from the aneurysm sac for rapid decompression of the cranial nerves. Application of this surgery for treatment of giant aneurysms of the trunk and bifurcation of the basilar artery is promising but requires further investigation. The surgery is also recommended for improving cerebral perfusion in the setting of complex stenotic occlusive lesions of the BCA: prolonged BCA stenoses, tandem ICA stenoses located in both the extracranial and intracranial segments, nonspecific vasculitis and arteriitis, subcranial aneurysms, kinking etc.

[Combination treatment of cerebral arteriovenous malformations using endovascular and microsurgical techniques]. / Kombinirovannoe lechenie arteriovenoznykh mal'formatsii golovnogo mozga s ispol'zovaniem éndovaskuliarnogo i mikrokhirurgicheskogo metodov.

MATERIAL AND METHODS: The study included 40 patients with cerebral AVMs. In the study group, 14 (35%) patients underwent microsurgical resection without preliminary embolization (1st group), and 26 (65%) patients underwent combined treatment (endovascular embolization and microsurgical intervention, 2nd group). The first group included patients with S&M grade I-III AVMs, and the second group included patients with S&M grade II-V AVMs. Treatment outcomes were evaluated with allowance for completeness of AVM resection, operative blood loss, duration of surgery, changes in clinical and neurological impairments according to the modified Rankin scale, and rate of neurological and surgical complications. RESULTS: According to postoperative findings, AVMs were totally resected in all patients. Persistent focal neurological symptoms developed in 2 (7.7%) cases in the second group; neurological complications occurred in 1 (7.1%) patient in the first group. The mean blood loss during resection of AVMs without preliminary embolization and embolized AVMs in patients with S&M grade I-III AVMs was 271.4 mL and 149.1 mL, respectively. The duration of surgery and blood loss did not differ significantly in microsurgery and combination treatment groups. CONCLUSION: Combination treatment, including microsurgical intervention after endovascular embolization, is an effective treatment for AVMs, in particular for high grade (S&M grade III-V) AVMs. Teamwork and coordination among the surgeon, endovascular surgeon, and radiologist in treatment of AVMs is a prerequisite for a good outcome.

[Surgical treatment of distal extracranial internal carotid artery aneurysms associated with pathological artery kinking]. / Operativnoe lechenie distal'nykh anevrizm ekstrakranial'nogo otdela vnutrennei sonnoi arterii, sochetayushchikhsya s ee patologicheskoi izvitost'yu.

Extracranial internal carotid artery (ICA) aneurysms located at the entrance of the skull are a rare pathology. Surgical treatment is indicated for this pathology because of the risk of arterio-arterial embolism and the development of cerebrovascular disease. The domestic and international literature reports single cases or small group cases of successful surgical treatment of patients with distal internal carotid artery aneurysms associated with pathological kinking of the artery. Open surgery for aneurysms of this localization is complicated because of a high injury risk associated with the approach. Endovascular interventions are not always possible due to the presence of degenerative changes in the vascular wall and pathological artery kinking. We propose a surgical option for creating a high-flow ec-ic bypass between the external carotid artery and the M2 segment of the middle cerebral artery. The article describes the results of successful application of this technique in three patients with distal extracranial internal carotid artery aneurysms associated with pathological kinking of the artery.

[Surgical treatment of «Mirror¼ aneurysms of the internal carotid artery]. / Khirurgicheskoe lechenie «zerkal'nykh¼ anevrizm vnutrennei sonnoi arterii.

BACKGROUND: A relatively high occurrence of "mirror" aneurysms of the anterior cerebral circulation in neurosurgical practice necessitates generalization of experience of using different surgical approaches. The choice of treatment is usually associated with the number of surgical stages. MATERIAL AND METHODS: Forty nine patients (19 males and 30 females) with mirror aneurysms of the anterior circulation underwent one- and two-step surgery at the Novosibirsk Federal Center of Neurosurgery in 2013-2015. The total number of bilateral aneurysms was 51 couples (102 aneurysms). The patients' age ranged from 19 to 66 years (mean age, 47.1±11.6 years). Most of the patients (47) underwent elective surgery; 2 patients were operated on in acute subarachnoid hemorrhage. RESULTS: Sixty nine microsurgical operations and 19 endovasal interventions were performed during the main step. Microsurgery alone was used in 34 cases; endovascular surgery alone was performed in 6 cases; a combination of the techniques was used in 9 cases. Ten patients underwent one-step surgery, and 39 patients underwent two-step surgery. The radicalness of surgery amounted to 94.1% for the microsurgical technique and 83.3% for the endovasal technique. The excellent and good functional outcome (modified Rankin scale, 0-2) was achieved in 46 (93.9%) patients, and the poor outcome (mRs, 3-5) was observed in 3 (6.1%) patients. CONCLUSION: Generalization of the results indicates that one-stage surgery is more preferable in the treatment of mirror cerebral aneurysms. However, the two-stage approach remains important and, in the case of certain anatomical peculiarities, is the only possible treatment. A combination of microsurgical and endovascular techniques improves clinical outcomes in treatment of mirror aneurysms of the anterior part of the cerebral arterial circle.

[Methods for Reducing Laser Speckles to Achieve Even Illumination of the Microscope Field of View in Biophysical Studies].

The aim of this work was to compare different speckle reduction techniques. It was shown that the use of devices based on liquid crystals only leads to partial reduction of speckle contrast. In quantitative luminescent microscopy an application of the mechanical devices when a laser beam is spread within the field of view turned out to be more efficient. Laser speckle noise was virtually eliminated with the developed and manufactured mechanical device comprising a fiber optic ring light guide and the vibrator that permits movement of optical fiber ends towards the laser diode during measurements. The method developed for the analysis of microarrays was successfully applied to the problem of speckle reduction.

[General approach to designing a device for artificial blood circulation]. / Obshchii podkhod k postroeniiu apparatury iskusstvennogo krovoobrashcheniia.

The systems approach to constructing extracorporeal circulation equipment enhances the university of this equipment by interchangeable choice of its structure, functional parameters and constructive implementation. The authors propose to use in the extracorporeal circulation equipment two (two- and four-pump) perfusion units with two types of constructively interchangeable perfusion pumps of various capacity.

Binding of nucleotides by T4 DNA ligase and T4 RNA ligase: optical absorbance and fluorescence studies.

The interaction of nucleotides with T4 DNA and RNA ligases has been characterized using ultraviolet visible (UV-VIS) absorbance and fluorescence spectroscopy. Both enzymes bind nucleotides with the K(d) between 0.1 and 20 microM. Nucleotide binding results in a decrease of absorbance at 260 nm due to pi-stacking with an aromatic residue, possibly phenylalanine, and causes red-shifting of the absorbance maximum due to hydrogen bonding with the exocyclic amino group. T4 DNA ligase is shown to have, besides the catalytic ATP binding site, another noncovalent nucleotide binding site. ATP bound there alters the pi-stacking of the nucleotide in the catalytic site, increasing its optical extinction. The K(d) for the noncovalent site is approximately 1000-fold higher than for the catalytic site. Nucleotides quench the protein fluorescence showing that a tryptophan residue is located in the active site of the ligase. The decrease of absorbance around 298 nm suggests that the hydrogen bonding interactions of this tryptophan residue are weakened in the ligase-nucleotide complex. The excitation/emission properties of T4 RNA ligase indicate that its ATP binding pocket is in contact with solvent, which is excluded upon binding of the nucleotide. Overall, the spectroscopic analysis reveals important similarities between T4 ligases and related nucleotidyltransferases, despite the low sequence similarity.