Biomedical subjects

Hiroyasu Kamiyama

Publications and source records attributed to Hiroyasu Kamiyama.

9 recordsLinked to original sources

PubMed2006

Clinical study of cerebrospinal fluid dynamics using 111In-DTPA SPECT in patients with subarachnoid hemorrhage.

The ventricle-to-background ratio and clearance rate constant measured by indium-111 diethylenetriaminepenta-acetic acid single photon emission computed tomography ((111)In-DTPA SPECT) were evaluated for predicting hydrocephalus in 16 patients at 2 to 3 weeks after onset of subarachnoid hemorrhage. The activity in the lateral ventricles, basal cistern, and hemispheric convexities was measured at 6, 24, and 48 hours after lumbar injection of radionuclide. In the follow-up study, eight patients developed hydrocephalus, and required ventriculoperitoneal shunting. Radioactivity measured in the hemispheric convexity did not reach peak activity within 48 hours. The clearance rate measured by applying the mono-exponential equation failed to show delayed clearance of radionuclide in hydrocephalus. The ratio between the ventricle and basal cistern measured at 6 hours postinjection was the best predictor of hydrocephalus (F(1, 30) = 42.84, p < 0.0001). These results suggest that a single (111)In-DTPA SPECT scan may be sufficient to identify patients at risk of developing hydrocephalus.

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PubMed2006

Simultaneous superficial temporal artery to middle cerebral or anterior cerebral artery bypass with pan-synangiosis for Moyamoya disease covering both anterior and middle cerebral artery territories.

Some patients with moyamoya disease treated by conventional surgical procedures may develop postoperative refractory ischemia and perioperative cerebral infarction in the anterior cerebral artery (ACA) territory. We present a novel operative procedure for moyamoya disease to avoid the risk of ischemia in the ACA territory, which consists of simultaneous superficial temporal artery (STA) to middle cerebral artery (MCA) or ACA bypass with pan-synangiosis, encephalo-duro-arterio-myo-synangiosis for the lateral frontal and temporal areas, and encephalo-galeo-arterio-synangiosis for the medial frontal area. This procedure can establish direct bypass to the ACA territory at the first intervention. Simultaneous STA-MCA and STA-ACA bypasses with pan-synangiosis is suitable for patients with moyamoya disease associated with severely impaired perfusion of the ACA territory requiring direct bypass surgery.

Adolescent↗

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

Experience from "double-insurance bypass." Surgical results and additional techniques to achieve complex aneurysm surgery in a safer manner.

BACKGROUND: "Double-insurance bypass" was recently advocated to avoid the risk of cerebral ischemia during prolonged temporary occlusion of the carotid artery. For large aneurysms needing temporary but prolonged obliteration of the internal carotid artery (ICA). We have attempted the double-insurance bypass in 15 patients and, herein, report the efficacies and limitations of the procedure, and surgical techniques to make this procedure safer. METHODS: We treated 15 patients with complex internal carotid aneurysms by clipping surgery with the aid of radial artery (RA) to proximal middle cerebral artery (MCA) bypass, so-called double-insurance bypass. We analyzed surgical results of the procedure. RESULTS: In 11 patients, the duration of temporary occlusion of the ICA could be prolonged for as long as 110 minutes (mean, 45 minutes) without any ischemic complications. One patient in the earlier period of our experience suffered extended cerebral infarction due to possible restricted blood flow through the RA, because the brachial artery was compressed by the firm shoulder joint and neighboring structures. Thereafter, we routinely monitored the blood pressure of MCA (MCABP) and never experienced such cortical infarctions. Another 3 patients, however, experienced ischemia in the territory of perforating arteries that originated from a segment that could not be perfused by the RA-MCA bypass. CONCLUSIONS: In combination with monitoring of MCABP, the double-insurance bypass can be a safer and more potent adjunctive procedure for the treatment of complex internal carotid aneurysms which require prolonged temporary occlusion of the ICA.

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PubMed2004

Determinants of intellectual outcome after surgical revascularization in pediatric moyamoya disease: a multivariate analysis.

OBJECTS: The aim of this study was to clarify predictors for poor intellectual outcome in pediatric moyamoya disease. METHODS: Fifty-two pediatric patients were included. Clinical diagnosis was transient ischemic attacks (TIA) in 35 and completed stroke in 17. Ten patients underwent indirect synangiosis through "small craniotomy," whereas the other 42 underwent superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis and indirect synangiosis through "large craniotomy." Full-scale IQ (FSIQ) was measured using the Wechsler intelligence scale for children (WISC) after surgery. Multivariate logistic regression models were applied to test the effect of clinical factors on intellectual outcome. RESULTS AND CONCLUSION: Eight patients revealed mentally impaired status (FSIQ<70). Multivariate analysis revealed that completed stroke and "small craniotomy" surgery were significantly associated with poor intellectual outcome. Odds ratios of each factor were 33.4 (95% CI, 2.4-474) and 19.6 (95% CI, 1.8-215) respectively. Early diagnosis and the revascularization procedure over as wide an area as possible may be essential to improve their intellectual outcome.

Cerebral Revascularization↗

PubMed2003

Operative anatomy and classification of the sylvian veins for the distal transsylvian approach.

Methods for preservation of the sylvian veins in the transsylvian approach have not been established because of the considerable variations. This study attempted to classify the sylvian veins to facilitate systematic dissection of the sylvian fissure for sylvian veins to be preserved. The operative anatomy of the sylvian vein was examined in 82 hemispheres. The type of drainage and the pattern of branching were investigated. The superficial sylvian vein (SSV) was classified into three types according to the number of stems draining into the dural sinus on the inner surface of the sphenoid bone: The SSV was absent or hypoplastic in eight cases, the SSV was single in 38 cases, and the SSV was double in 36 cases. The SSV drained into neither the sphenoparietal sinus nor the cavernous sinus in nine cases. An anastomosis between the SSV and the deep middle cerebral vein (DMCV) was observed in 42 cases. The frontobasal bridging vein (FBBV) drained into the sphenoparietal sinus in 47 cases. The type of connection was further subdivided into four types according to the connections with the DMCV and FBBV. The venous anatomy of sylvian fissure indicates that dissection (skeletonization) of the main stem of sylvian veins from the temporal lobe should be performed to preserve the tributaries from the frontal lobe.

Brain Neoplasms↗

PubMed2003

Subarachnoid hemorrhage associated with clival chordoma--case report.

A 66-year-old man presented with clival chordoma associated with subarachnoid hemorrhage. Computed tomography showed subarachnoid hemorrhage in the right ambient cistern and a well-enhanced tumor in the petroclival region. Surgical exploration performed on the day of admission showed a clot in the tumor. The tumor was totally removed. Histological examination showed hemorrhage between the tumor and the dura. The diagnosis was clival chordoma. Subarachnoid hemorrhage in chordoma seems to occur by spreading of intratumoral hemorrhage into the subarachnoid space due to dural invasion.

Aged↗

PubMed2003

[Clinical manifestations of infantile moyamoya disease].

PURPOSE: The present study aimed to clarify clinical manifestations of infantile moyamoya disease by comparing them with those of schoolchild moyamoya disease. SUBJECTS AND METHODS: This study included a total of 55 patients who were diagnosed as moyamoya disease on cerebral angiography. Their medical records were precisely evaluated. CT or MRI was performed to examine the location of cerebral infarction in all subjects. Cerebral blood flow was measured in 33 patients before surgery, using the 133-xenon inhalation method and single photon emission computed tomography (SPECT). Postoperative full-scale IQ (FSIQ) was also examined. RESULTS: Of 55 patients, onset age was < 6 yr in 32 (infantile group) and > or = 6 yr in 23 (schoolchild group). Completed stroke was significantly more frequent in the infantile group than in schoolchild group (p = 0.0014). Incidence of cerebral infarct was also higher in the infantile group than in the schoolchild group (p = 0.0023). PCA stenosis/occlusion was observed in 14 of 32 infantile patients, but only in 4 of 23 schoolchild patients (p = 0.0474). Mean cerebral blood flow value was significantly lower than control value in the infantile group, but not in the schoolchild group. The effect of bypass surgery on cerebral ischemic attack was satisfactory in both groups. However, the postoperative FSIQ value was significantly lower in the infantile group than in the schoolchild group (p = 0.0452). CONCLUSIONS: The present study showed that infantile moyamoya disease involves a higher risk for cerebral infarct and completed stroke due to its more advanced stage, and that earlier diagnosis and treatment should be performed to improve the mental prognosis of patients.

Adolescent↗

PubMedDate not supplied

Subarachnoid hemorrhage as a result of fungal aneurysm at the posterior communicating artery associated with occlusion of the internal carotid artery: case report.

BACKGROUND: Fungal or "true" mycotic aneurysms of the intracranial circulation are very rare. Rupture of a fungal aneurysm is fatal in almost 100% of cases. CASE DESCRIPTION: We report a 65-year-old woman with a ruptured fungal aneurysm on the posterior communicating artery associated with occlusion of the internal carotid artery. She had a past history of gastric malignant lymphoma and subsequent granulocytopenia. She survived after surgical treatment including trapping of the aneurysm and a superficial temporal artery-to-middle cerebral artery bypass. CONCLUSION: Improved immune response at the time of the onset of subarachnoid hemorrhage, as well as additional vasoreconstructive surgery, may have contributed to favorable outcome after surgical treatment.

Aged↗