2 cases of deep arteriovenous malformations combined with aneurysms of the anterior ciliary artery

The paper presents two cases of high-surgical-risk deep arteriovenous malformations (AVM) concurrent with aneurysms of the middle portion of the anterior ciliary artery (a male aged 35 years and a female aged 24 years). In the former case, aneurysm and large AVM in the left visual tuber were causes of 4 hemorrhages. In the latter, AVM of subcortical nodes and internal capsule were responsible for single hemorrhage. The patients underwent intraoperative embolization of the anterior ciliary artery followed by its clipping. This allowed the authors to exclude aneurysm and to achieve obliteration of the bulk of AVM. Operation were performed under intraoperative guidance of motor and speech functions. Residual AVM were exposed to proton beam radiation. The outcomes of treatment were good. After 4 months of surgery, the male had no neurological disorders; in the female motor and speech disorders were associated with prior hemorrhage.     

Direct intervention into giant partially thrombotic fusiform aneurysms of the posterior cerebral artery

The paper considers surgical treatment of patients with partially thrombotic giant and fusiform aneurysms of the posterior cerebral arteries (PCA), which is a challenge of cerebrovascular neurosurgery. Giant, fusiform aneurysms are clinically manifested themselves as a mass effect in 80% of cases and as spontaneous subarachnoidal hemorrhage in 20%. Due to their vicinity of the brain stem, giant aneurysms of PCA in any clinical course present a real threat to a patient's life. A case of clipping of partially thrombotic giant aneurysm of PCA by means of tunnel clips to form the wall of a vessel from an apron cut from the aneurysmal wall is considered in detail. Surgical treatment of partially thrombotic giant and fusiform aneurysms is identified as an individual problem of cerebrovascular neurosurgery, which awaits a sophisticated study in order to define an adequate surgical treatment.     

Ischemic tolerance (preconditioning) of the brain

Ischemic tolerance (preconditioning) is taken to mean a short ischemic episode subfatal to cells that activates the protective endogenous mechanisms that ensure tolerance of further longer and more severe episodes of ischemia by the organ (tissue). The present review attempts to analyze information on ischemic preconditioning in the light of the possible use for brain protection. Experimental models, temporal aspects, crossed tolerance, genomic reaction, and mechanisms are considered. There is evidence for human ischemic preconditioning.     

Effect of long-term hypokinesia on characteristics of phasic-tonic motor activity in monkeys

Male rhesus-monkeys, 5-6 years old, were kept in recumbency for a long period of time during which they had to perform phasic-tonic motor tests. The monkeys showed significant changes in the tonic component of the motor act which led to a substantial deterioration of performance parameters on hypokinesia days 20 to 30. The process of recovery began immediately after exposure and on readaptation days 14-15 the tonic component of the motor act returned to normal. The motor skill which is a consecutive chain of phasic and tonic components can be viewed as an adequate model of a voluntary motor act. This may be used for measuring quantitatively functional changes of the motor apparatus and for studying the effect of different agents on primate motor functions.     

Participation of GABA--benzodiazepine receptor complex in the anxiolytic effect of piracetam

It is established that bicuculline, picrotoxin, and flumazenil (agents blocking different sites of GABA receptor) decrease the anxiolytic effect of piracetam as manifested in the conflict situation test. The most pronounced interaction was observed between piracetam and flumazenyl. On the background of antagonist action, piracetam inhibited the effects of flumazenil (but not those of bicuculline and picrotoxin). Based on these data, it is assumed that the anxiolytic effect of piracetam is mediated to some extent by benzodiazepine site of the GABA-benzodiazepine receptor complex.     

Microsurgical treatment of cerebral arteriovenous malformations in Burdenko Neurosurgical Institute (recent experience)

Recently the number of AVM resections in Burdenko Neurosurgical Institute has been increased dramatically. Aim of this study was to assess the results of open surgery in our clinic in modern neurosurgical era. Consecutive series if 160 patients with AVM treated using microsurgical technique since 2009 till 2011 was analyzed. Spetzler-Martin score distribution was: grade I--29 (18.1%) cases, grade II--84 (52.5%), grade III--38 (23.8%), grade IV--9 (5.6%). Patients with grade V AVMs were not operated. Treatment options included: AVM resection in 143 (89.4%) cases, embolization followed by resection in 15 (9.3%) and clipping of afferents in 2 (1.3%). Glasgow outcome scale score distribution was the following: V (good recovery)--70 (43.7%), IV (moderate disability)--71 (44.4%), III (severe disability)--16 (10%), II (vegetative state)--1 (0.6%) and I (death)--2 (1.3%). Microsurgery remains the primary option for radical treatment of cerebral AVMs. Careful selection of patients and planning of surgery are crucial for good outcomes.     

Arterial wide-section anastomoses: experimental study on animals

A mechanical device for making arterial wide-section anastomoses was tested on a series of 15 laboratory rabbits. End-to-side anastomoses were made using a vein graft and they functioned in 93.1% of cases, as evidenced by intraoperative Doppler studies. When an anastomosis is made, the mean duration of temporary blood flow arrest in the rabbit aorta averaged 2 min. According to outcomes, the survived animals were divided into 3 groups: Group 1 comprised 2 (13.3%) rabbits that died within 10-12 hours after surgery and had significant symptoms of anastomotic dysfunction. Group 2 included 8 (53.3%) animals that died 2-3 days after surgery. They moved 5-6 hours following surgery without assistance, which was indicating of anastomotic functioning. Group 3 consisted of 3 (20%) rabbits that survived 2 weeks. Autoptic studies revealed no anastomic thrombosis in Group 2 animals. Group 3 animals were noted to have signs of allograft thrombosis and rejection. Thus, it is expedient to continue studies to make arterial wide-section anastomoses, by using the above device, in order to introduce this procedure into clinical practice.