Biomedical subjects

Takayuki Mizunari

Publications and source records attributed to Takayuki Mizunari.

5 recordsLinked to original sources

PubMed2005

Method for measuring sinus and vein pressure during surgery: technical note.

BACKGROUND: Measurement of dural sinus or drainage vein pressure is useful for determining the appropriate treatment for some patients. We report a novel measurement procedure that reduces bleeding from the needle puncture site as well as further tearing of the wall. METHODS: The vessel is punctured through the patch by gelatin sponge with fibrin sealant and a siliconized elastic needle is introduced. After obtaining the desired measurements, the needle is withdrawn through the fibrin sealant-bearing patch whose presence facilitates sealing of the puncture site. To further decrease the incidence of complications due to incomplete hemostasis, an additional identically prepared path is placed over the site. RESULTS: We have used this method in several operations and have encountered no complications. Our method also makes it possible to safely approach the drainers of pial arteriovenous malformations. CONCLUSIONS: Our method is easy and convenient and prevents the leakage of blood from the puncture site and further tearing of the venous wall.

Cerebral Veins↗

PubMed2005

The long-term effects of transluminal balloon angioplasty for vasospasms after subarachnoid hemorrhage: analyses of cerebral blood flow and reactivity.

BACKGROUND: Transluminal balloon angioplasty (TBA) has come into wide use for management of symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH). The long-term effects of TBA in this clinical context on cerebral blood flow (CBF) and the functional properties of the arterial wall after aneurysmal SAH remain controversial. We therefore studied these effects. METHODS: All patients underwent unilateral TBA. Xenon-enhanced computed tomography was performed for an average of 18 days after TBA to measure CBF and cerebrovascular reactivity (CVR). Cerebral blood flow and CVR were compared between the side of TBA and the contralateral side. RESULTS: Nineteen vascular territories were treated successfully with TBA in 12 patients. Angiographic improvement of vasospasm was demonstrated in all 12 patients, and 9 (75%) patients showed neurological improvement. After balloon angioplasty, global CBF was 35.1 +/- 8.2 mL/100 g per minute, with CBF on the side with TBA (37.8 +/- 10.3 mL/100 g per minute) being essentially the same as that on the other side (P = .0671, paired Student t test). Likewise, reactivity to acetazolamide did not differ significantly between sides (P = .0817). CONCLUSION: Transluminal balloon angioplasty increased proximal vessel diameters but showed no significant influence on CBF or vascular reactivity 3 weeks later. Benefits presumably were short term, but the procedure was clinically safe.

Adult↗

PubMed2005

Efficacy of edaravone, a free radical scavenger, for the treatment of acute lacunar infarction.

The effect of edaravone as an inhibitor of ischemic brain damage in addition to routine treatment was retrospectively examined in 70 patients with lacunar infarction who were admitted within 24 hours of symptom onset. Clinical status was assessed using the National Institutes of Health Stroke Scale (NIHSS). The modified Rankin Scale (MRS) was used to assess clinical outcomes at 3 months after onset, with a good outcome defined as MRS score < or =2. Risk factors were also evaluated, including evidence of hypertension, diabetes mellitus, hyperlipidemia, coronary heart disease, and a history of smoking longer than 2 months. The probability of a good outcome and independence at 3 months was assessed by backward stepwise logistic regression analysis based on the maximum likelihood ratio. Administration of edaravone yielded an odds ratio with multivariate adjustment of 6.49 (95% confidence interval, 1.35 to 50.32; p < 0.05) for a good outcome at 3 months. Higher baseline NIHSS score and higher age also adversely affected the outcome at 3 months (p < 0.005). Administration of edaravone improves the outcome of patients with lacunar infarction.

Acute Disease↗

PubMed2004

Anterior communicating artery aneurysm in the sella turcica: case report.

BACKGROUND: Only 3 such reported intrasellar aneurysms have arisen from the anterior communicating artery. CASE DESCRIPTION: A neurologically normal 38-year-old man complaining of headache underwent cranial magnetic resonance imaging, which showed a heterogeneously enhancing, partially calcified intrasellar mass. The normal pituitary gland was identified at the bottom of the sella, and the optic chiasm was located superior to the aneurysm. Digital subtraction angiography and three-dimensional computed tomography angiography demonstrated the mass to be a partially thrombosed anterior communicating artery aneurysm. Frontotemporal craniotomy was performed, but initial attempts to occlude the neck of the aneurysm were unsuccessful. We could not expose the dome of the aneurysm or confirm the anatomic relationship of the pituitary to the aneurysm. The patient declined further intervention, and close follow-up has been maintained. CONCLUSION: Our case suggested that unlike intrasellar aneurysms arising from the internal carotid artery, intrasellar aneurysms originating from the anterior communicating artery are likely to present difficulty in dissecting the neck of the aneurysm from the bilateral optic nerves and pituitary stalk, impeding direct aneurysm clipping. When we operated upon a patient with a large unruptured intrasellar aneurysm originating from the anterior communicating artery via the prechiasmatic space, we encountered considerable technical difficulty.

Adult↗

PubMed2003

[The relationship between extracranial carotid atherosclerosis in an ultrasound study and periventricular hyperintensity in MR images].

We have evaluated the relationship between carotid atherosclerotic change and periventricular hyper intensity (PVH). PVH was studied in 66 cases with cerebral thrombosis, comparing them with another group of age-matched controls, which consisted of 29 cases with hypertension, diabetes, and hypercholesteremia. MRI (fluid attenuated inversion recovery) and B-mode carotid ultrasonography of each lesion were analyzed. Thrombosis lesions, compatible with neurological manifestation were divided into two types, cerebral cortical type (including centrum semiovale type) and small infarction in the deep subcortical type. PVH was classified into 4 grades, none, rims/caps, patchy and diffuse. Smooth PVH was, adjoining the anterior/posterior angles and the margins of the lateral ventricles, were defined as caps and rims. Irregular PVH areas, confluent with each other, were defined as patchy, while diffuse PVH areas extending below the cortex beyond the level of the corpus callosum were defined as diffuse. Carotid atherosclerosis was evaluated using B-mode carotid ultrasonography. The severity of carotid atherosclerosis was assessed by using two indicators; incidence of carotid atherosclerosis and maximum percentage diameter of the stenosis areas. Patchy and diffuse type PVH was frequent in the thrombosis group. On B-mode carotid ultrasonography, diffuse PVH was prominent in patients with stenotic change and high maximum percentage of stenosis, but none/rims/caps PVH was accompanied by variable B-mode carotid ultrasonographical findings. Six patients had ulcerated plaques and they suffered more frequently with diffuse PVH. Diffuse PVH was more frequent in cases with severe carotid stenosis than in other PVH types. These findings suggested that large vessel atherosclerosis could result in diffuse PVH.

Aged↗