[Intraoperative rupture of cerebral aneurysm--incidence and risk factors].

OBJECTIVE: To reveal and assess risk factors for intraoperative rupture (IOA) of aneurysms, which will reduce the incidence of this complication and improve the outcome of treatment. METHODS: Direct surgical interventions made in 610 cerebral aneurysms at the Vascular Department of N.N. Burdenko Research Institute of Neurosurgery, Russian Academy of Medical Sciences, in 2002 to 2005 were analyzed in 519 patients. Under study were the following factors: onset of IOA; site and anatomic and topographic features of aneurysms; time of an operation (acute or cold subarachnoidal hemorrhage), presence or absence of hemorrhage in the history, rate and severity of hemorrhage (according to the Hunt-Hess classification), temporary clipping of the nutrient arteries. RESULTS: The incidence of IOR was 11.7% of the operated aneurysms and 13.7% of the patients. Ruptures occurred during aneurysmal manipulations in 96% of cases. Moderate and significant hemorrhages requiring a surgeon to make additional measures to improve them more frequently occurred in IOR. The highest rate of IOR was recorded at surgery for aneurysms of the anterior cerebral artery--the anterior communicating artery. The incidence of ruptures increased with their greater sizes. There was a significant increase in the incidence of IOR in aneurysms with diverticula (p = 0.004) and with wide necks (p = 0.04). The level of IOR in the patients operated on within the first 3 weeks after SAK was 3 times higher than in those operated on in the cold period (p < 0.05). The incidence of IOR was rather low in the treatment of asymptomatic aneurysms (2.5%). The risk for IOR was higher in patients with recurring hemorrhage. Preventive temporary occlusion substantially lessens the risk of IOR. CONCLUSION: The low rate of IOA in the treatment of asymptomatic aneurysms is another argument in favor of the development of surgery for unruptured asymptomatic aneurysms. Timely temporary clipping of the nutrient artery at surgery substantially reduces the risk of IOR in all cases.

[Intraoperative contact Doppler ultrasonography in the surgery of cerebral aneurysm].

Vascular occlusion leading to the development of an ischemic focus or incomplete aneurysm closure is one of the main causes that deteriorate the total results of surgical treatment in patients with cerebral aneurysms. The study covering 50 patients with 54 aneurysms who were evaluated for vascular patency by contact Doppler ultrasonography (CDUS) assessed the role and reliability of this technique. In the study group, the ratio of males to females was 30:24, their mean age was 44 years (23-67 years); the ratio of patients with acute subarachnoidal hemorrhage (SAH) to those without SAH was 24:30. The functional outcomes were assessed by a modified Rankin scale and compared with those in the control group. The clip site was inspected by the results of CDUS in 19 (31.7%) cases; clip reposition was made in 16 (26.7%) cases due to vascular stenosis; an additional clip was use to exclude the aneurysmal functioning part in 1 (1.7%) case. Vascular stenosis was detected in 2 (3.3%) cases; however, the position of clips remained unchanged since aneurysm was excluded under the conditions of its rupture. According to the modified Rankin scale, good results were slightly more in the study group of "acute" patients than in the control group: 96.7% versus 90%; the similar results were obtained in non-SAH patients: 66.7% versus 62.5%; lambda < 1.36). CDUS is a noninvasive, simple, reliable, and inexpensive technique for blood flow evaluation.

[Familial intracranial aneurysms].

The study included 38 patients with intracranial aneurysms, whose close relatives had experienced intracranial hemorrhages. The patients' relatives were divided into 2 groups according to the verification of the source of hemorrhage. The individuals at risk for aneurysmal disease in whom aneurysms should be sought before their rupture were examined. The patients with familial aneurysms were found to tend to rupture at younger age than those without familial aneurysms (the so-called sporadic aneurysms). The high rates of mortality due to intracranial bleeding were observed among the relatives of patients from the study group. Screening study of the first-order relatives of the patients with prior aneurysmal subarachnoidal hemorrhage is the method of choice in detecting unruptured cerebrovascular aneurysms. Early detection and switching-off of asymptomatic aneurysms may reduce mortality and disability rates in this group of patients.

[Surgical treatment for asymptomatic non-ruptured intracranial aneurysms]. / Khirurgicheskoe lechenie asimptomnykh nerazorvavshikhsia intrakranial'nykh anevrizm.

The study was undertaken to analyze the outcomes of treatment in 37 patients with 44 non-ruptured aneurysms (NRA) at different sites. The paper presents a detailed classification of NRA, identifies individuals at risk for aneurysmal disease in whom an active search for aneurysms until they rupture is recommended to prevent aneurysmal subarachnoidal hemorrhages and their sequels. Total aneurysmal exclusion was achieved in 93.2% of the cases; the aneurysmal walls were consolidated with surgical gauze in 7.2%. There were no fatal cases. Postoperative progression of focal neurological symptoms was noted in 4 patients. In 3 patients, these symptoms were entirely reversible. All NRAs should be operated on irrespective of their size particularly in young and middle-aged patients since this is technically possible and there are no concomitant diseases that make surgery contraindicated. It is expedient to perform computed or magnetic resonance imaging in combination with angiography in risk-group patients in order to reveal or exclude aneurysm.

[Pharmacological protection of the brain during surgery in patients with giant cerebral aneurysms]. / Farmakologicheskaia zashchita mozga vo vremia operatsii u bol'nykh s gigantskimi arterial'nymi anevrizmami tserebral'nykh sosudov.

The authors discuss the results of pharmacological protection of the brain, consisting in intraarterial or intravenous infusion of drugs (sodium thiopental, nimodipine, ketamine) during intracranial interventions in 13 patients with giant arterial aneurysms of the anterior portions of Willis' circle. In some patients drug protection of the brain prevented the development of ischemic focus in the basin of temporarily occluded vessel. Intraarterial infusion of protector drugs is preferable because it allows decreasing the doses and severity of untoward hemodynamic effects.

[The postoperative monitoring of intracranial pressure in patients in the acute period of aneurysmatic hemorrhage]. / Posleoperatsionnyi monitoring vnutricherepnogo davleniia u bol'nykh v ostrom periode anevrizmaticheskogo krovoizliianiia.

Changes in intracranial pressure (ICP) and cerebral circulation were evaluated from Doppler transcranial ultrasound (DTU) in 29 patients with spontaneous aneurysmal hemorrhage in acute rupture. There is a tendency for the pulse wave amplitude (PWA) of ICP to increase concurrently with higher ICP values (r = 0.768, p < 0.01), the tendency being smoother in patients with severe diffuse spasm (r = 0.573, p < 0.01). There was also a linear correlation between the ICP values and the pulse index of blood flow velocity (r = 0.783, p < 0.01). Evidence is given for the possibility of indirect assessment of ICP from DTU data and for that of indirect evaluation of cerebral perfusion from ICP monitoring data. In the latter case, the authors used a ICP PWA ratio. The findings suggest that the decrease in PWA/ICP values by less than 0.2 during intracranial hypertension and severe diffuse arterial spasm corresponds to the reduction in cerebral blood filling beyond the critical values.

[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 interaction of humoral, metabolic and myogenic regulation of the cerebral circulation in unilateral occlusion of the internal carotid artery]. / Vzaimodeistvie gumoral'noi, metabolicheskoi i miogennoi reguliatsii mozgovogo krovoobrashcheniia pri odnostoronnei okkliuzii vnutrennei sonnoi arterii.

Transcranial dopplerography revealed an asymmetry in middle cerebral arteries in unilateral occlusion of the inner carotid artery. The reactivity of cerebral vessels to carbonic acid diminishes on the side of the occlusion. In absence of the brain tissue infarction, surgical revascularization leads to a partial normalizing of the reactivity. The data obtained suggests a considerable alteration of the interaction among humoral, metabolic and myogenic regulations of cerebral blood flow in unilateral occlusion of the inner carotid artery.