Anterior Petrosectomy Approach to Infraclinoidal Basilar Artery Aneurysms: The Emerging Role of the Neuro-otologist in Multidisciplinary Management of Basilar Artery Aneurysms

We tested the hypothesis that nitric oxide (NO) plays a role in CBF autoregulation in the brain stem during hypotension. In anesthetized rats, local CBF to the brain stem was determined with laser-Doppler flowmetry, and diameters of the basilar artery and its branches were measured through an open cranial window during stepwise hemorrhagic hypotension. During topical application of 10−5 mol/L and 10−4 mol/L Nω-nitro-L-arginine (L-NNA), a nonselective inhibitor of nitric oxide synthase (NOS), CBF started to decrease at higher steps of mean arterial blood pressure in proportion to the concentration of L-NNA in stepwise hypotension (45 to 60 mm Hg in the 10−5 mol/L and 60 to 75 mm Hg in the 10−4 mol/L L-NNA group versus 30 to 45 mm Hg in the control group). Dilator response of the basilar artery to severe hypotension was significantly attenuated by topical application of L-NNA (maximum dilatation at 30 mm Hg: 16 ± 8% in the 10−5 mol/L and 12 ± 5% in the 10−4 mol/L L-NNA group versus 34 ± 4% in the control group), but that of the branches was similar between the control and L-NNA groups. Topical application of 10−5 mol/L 7-nitro indazole, a selective inhibitor of neuronal NOS, did not affect changes in CBF or vessel diameter through the entire pressure range. Thus, endothelial but not neuronal NO seems to take part in the regulation of CBF to the the brain stem during hypotension around the lower limits of CBF autoregulation. The role of NO in mediating dilatation in response to hypotension appears to be greater in large arteries than in small ones.

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Contractions induced by NO synthase inhibition in isolated rat basilar artery: Role of the endothelium and endogeneous vasoconstrictors

Neurological Research ◽

10.1080/01616412.1998.11740486 ◽

1998 ◽

Vol 20 (1) ◽

pp. 63-72 ◽

Cited By ~ 10

Author(s):

Ralf Hempelmann ◽

Rainer Prade ◽

Maximilian Mehdorn ◽

Albrecht Ziegler

Keyword(s):

Basilar Artery ◽

No Synthase ◽

Isolated Rat

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Possible role of leukotrienes in hypoxic contraction of canine isolated basilar artery

British Journal of Pharmacology ◽

10.1111/j.1476-5381.1991.tb09839.x ◽

1991 ◽

Vol 103 (3) ◽

pp. 1629-1632 ◽

Cited By ~ 3

Author(s):

Mai Gu ◽

Douglas A. Elliott ◽

Bill Y. Ong ◽

Deepak Bose

Keyword(s):

Basilar Artery

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Effects of cervical sympathectomy on vasospasm induced by meningeal haemorrhage in rabbits

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2006000400006 ◽

2006 ◽

Vol 64 (3a) ◽

pp. 572-574 ◽

Cited By ~ 5

Author(s):

Antônio Tadeu de Souza Faleiros ◽

Francisco Humberto de Abreu Maffei ◽

Luiz Antonio de Lima Resende

Keyword(s):

Cerebral Vasospasm ◽

Basilar Artery ◽

Sympathetic Ganglion ◽

Cervical Sympathectomy

This study investigates the role of cervical sympathectomy in the prevention of acute vasospasm induced by meningeal haemorrhage in rabbits. Sixteen adult English Norfolk rabbits were divided into 2 experimental groups: bilateral cervical sympathectomy of the superior sympathetic ganglion (SSSG, n=8), and bilateral SSSG and sympathectomy of the inferior sympathetic ganglion (SISG, n=8). Other 24 animals were used as controls. Basilar artery diameter was evaluated by angiography. SSSG protected the animals against developing cerebral vasospasm; SSSG associated with SISG did not increase this effect.

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