Neurosurgery
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In human somatic cells, telomeres shorten with successive cell divisions, resulting in progressive genomic instability, altered gene expression, and cell death. Recently, telomere-specific deoxyribonucleic acid-binding proteins, such as telomeric repeat binding factor-1 (TRF1), have been proposed as candidates for the role of molecules regulating telomerase activity, and they have been suggested to play key roles in the maintenance of telomere function. The present study was designed to assess TRF1 expression in human astroglial brain tumors and to speculate on the clinical implications of its expression. ⋯ Our findings suggest that the loss of TRF1 expression capability, as a result of down-regulation of TRF1 expression in malignant gliomas cells, may play a role in the malignant progression of astroglial brain tumors.
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Clinical features of aneurysms of the posterior cerebral artery: a 15-year experience with 21 cases.
To investigate the characteristic clinical behavior and develop guidelines for the clinical management of posterior cerebral artery aneurysms, we reviewed 21 cases treated during a 15-year period. ⋯ Posterior cerebral artery aneurysms have specific clinical characteristics compared with aneurysms located elsewhere. The aneurysmal site and size and the surgical technique did not significantly influence treatment outcomes.
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Complex basilar apex aneurysms (large size, wide and complex neck, tortuous parent vessels) continue to pose a challenge in treatment. Endovascular treatment has a high risk of recanalization, and surgical treatment is limited by the space and time necessary to achieve safe clipping. To overcome these obstacles, a modification of previously reported approaches was developed. The pretemporal transzygomatic transcavernous approach and a clipping strategy were used in the treatment of 21 high-complexity basilar apex aneurysms. ⋯ We report the largest series of a unique, challenging group of complex basilar apex aneurysms treated with the pretemporal transzygomatic transcavernous approach, which provided improved safety of clipping by 1) increased visualization of the basilar apex and perforator arteries, 2) improved maneuverability of clip application, 3) a safer perforator-free location, and 4) preservation of brainstem collateral flow.
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Brainstem cavernous malformations that seem to come to a pial or ependymal surface on preoperative magnetic resonance imaging studies may, in fact, be covered by an intact layer of neural tissue. For cavernous malformations in the cerebral peduncle, intraoperative stimulation mapping with a miniaturized probe can determine whether this overlying tissue harbors fibers in the corticospinal tract. In addition, intermittent monitoring with transcranial motor evoked potentials (TcMEPs) helps to protect this vital pathway during resection of the lesion. ⋯ Stimulation mapping of the corticospinal tract and intermittent TcMEPs is a safe and simple surgical adjunct. Expanded monitoring of the motor pathway during the resection of cerebral peduncle cavernous malformations may improve the safety of these operations.
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We sought to expand our assessment of calcium alginate as an embolic agent in an animal model of a cerebral arteriovenous malformation (AVM). The objective of this study was to assess the long-term biocompatibility and stability of calcium alginate in AVM swine models that survived from 1 to 6 months. ⋯ Over a period of 6 months, calcium alginate was an effective endovascular occlusion material that blocked blood flow to the inferior portion of the RM. The chronic AVM model verified the long-term stability and biocompatibility of calcium alginate.