[Structural features of cerebral arteriovenous malformations according to the data of optic microscopy and scanning electron microscopy of corrosion specimens].

The aim of this study was to investigate structure of cerebral arteriovenous malformations (AVM). We examined and treated 5 patients with AVMs of cerebral hemispheres. Treatment consisted of endovascular embolization with subsequent surgical resection of AVM. The series included 3 female and 2 male patients (age 19-44, mean - 28 years). Histoacryl (B. Braun, Germany) was used for embolization. Corrosion specimens were prepared according to standard technique and examined using optic and scanning electron microscopy. AVMs had similar structure. Casts were formed by distal segments of afferent arteries, fistulas, interjacent venous vessels, proximal segments of draining veins and vessels of angiomatous surrounding. The latter consisted of abnormal network of small arteries, veins, fistulas and dilated capillaries. The most variable length and formation of glomeruli was characteristic for interjacent venous vessels. AVMs extensively anastomosed with cerebral vessels. Big amount of aneurysms and aneurysmatic bulgings was present. Aneurysms of intranidal segment of afferent artery and angiomatous vessels are demonstrated.

[Arteriovenous malformation of septum pellucidum in combination with persistent trigeminal neuralgia].

A 16-year-old boy with arteriovenous malformation (AVM) of septum pellucidum in combination with left side persistent trigeminal artery (PTA) is described. Presentation of AVM included severe intracranial hemorrhage and the lesion was removed surgically. The case deserves interest for two reasons. 1) The observation demonstrates the possibility of increased pressure in the afferent arteries of AVM. It was illustrated by distinctive displacement of the zones of the hemodynamical balance around the circle of Willis. The raised pressure in conditions of shunting can be explained using principles of the constant shear stress in the vascular system. 2) The observation of the features of venous system that may be causative for PTA. These features included presence of the large anastomotic vein between petrosal and cavernous sinuses, enlargement of petrosal sinuses and shrinking of transverse sinus ipsilateral to PTA.

[2 cases of deep arteriovenous malformations combined with aneurysms of the anterior ciliary artery]. / Dva nabliudeniia glubinnykh arteriovenoznykh mal'formatsii v sochetanii s anevrizmami perednei vorsinchatoi arterii.

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.

[The persistent trigeminal artery in vascular brain diseases]. / Persistiruiushchaia trigeminal'naia arteriia pri sosudistykh zabolevaniiakh golovnogo mozga.

This paper presents 12 cases of the persistent trigeminal artery (PTA) concurrent with cerebrovascular diseases. In 7 patients, PTA was accompanied by cerebral aneurysms, 2 had prior subarachnoidal hemorrhage (SAH) of unknown origin, other 2 patients had acute transient ischemic attacks. In one case, PTA was concomitant with arteriovenous malformation. Clinical features and hemodynamic variants of PTA are described. Diagnostic modalities and surgical management of combinations of PTA and aneurysms in the presence of SAH are discussed.

[The procedure for the surgical treatment of combined arteriovenous malformations and arterial aneurysms of the brain]. / Taktika khirurgicheskogo lecheniia sochetannykh mal'formatsii i arterial'nykh anevrizm golovnogo mozga.

To choose the optimal surgical treatment, the follow-ups of 25 patients with arteriovenous malformations (AVMs) concurrent with arterial aneurysms who had been surgically treated were considered. Twenty four patients experienced spontaneous subarachnoidal hemorrhage, 16 of them were repeated and multiple. The accurate diagnosis of the source of bleeding was associated with objective difficulties. With allowance for intraoperative findings. AVMs caused hemorrhage in 14 (58%) cases, aneurysms in 6 (25%). AVMs and aneurysms in 4 (17%). Thirteen (52%) patients were operated on AVMs and aneurysms in one or two steps, 5 had operations only on aneurysms, 7, on AVMs alone. Taking into account ruptures and higher sizes of aneurysms after AVM dissection, it is concluded that it is necessary to immediately exclude saccular bifurcating aneurysms irrespective of the cause of bleeding. Possible variants of policy decisions are dealt with, by taking into account the specific features of the location of AVMs and aneurysms-the sources of hemorrhage. One-stage surgical interventions into AVMs and aneurysms are recognized to be optimal.