Yasunori Kodama

Morphological differences between ruptured and unruptured cases in middle cerebral artery aneurysms.

OBJECTIVETo elucidate the morphological differences between ruptured and unruptured aneurysms, three-dimensional digital subtraction angiography was performed in 44 cases (20 unruptured, 24 ruptured) of middle cerebral artery aneurysm. METHODSWhen the neck was located on the extension of the midline of the parent artery, it was defined as Type C; when it was not, it was defined as Type D. Aspect ratio (AP ratio; dome/neck ratio) and daughter artery ratio (DA ratio; diameter of the larger daughter artery/diameter of the smaller daughter artery) were calculated, and these ratios were compared for ruptured and unruptured cases. RESULTSNineteen cases were Type C and 25 cases were Type D. χ2 test revealed that there were significantly more ruptured cases among Type C (14 out of 19) compared with Type D (10 out of 25) (P < 0.05). AP ratios were 2.24 ± 0.75 for ruptured cases and 1.56 ± 0.58 for unruptured cases. DA ratios were 1.53 ± 0.54 in ruptured cases and 2.14 ± 0.80 for unruptured cases. Both showed significant differences (P < 0.01). In cases with an AP ratio of 1.8 or greater and a DA ratio less than 1.7, 13 out of 15 (87%) were ruptured cases. On the contrary, in cases with an AP ratio less than 1.8 and a DA ratio of 1.7 or greater, 12 out of 13 (92%) were unruptured cases. CONCLUSIONType C and equality of the diameters of two daughter arteries, together with high AP ratios, seem to be morphological factors that associate with aneurysmal rupture.

Evaluation of relation among aneurysmal neck, parent artery, and daughter arteries in middle cerebral artery aneurysms, by three-dimensional digital subtraction angiography

Intracranial aneurysms usually occur at arterial bifurcations. However, in middle cerebral artery (MCA) aneurysms, we often find that the aneurysmal neck does not necessarily exist just on the arterial bifurcation. In this study, we have evaluated the relation among aneurysmal neck, parent artery, and daughter arteries in middle cerebral artery aneurysms, by three-dimensional digital subtraction angiography. Twenty consecutive patients (9 men and 11 women) with MCA aneurysms were examined. The total number of aneurysms was 22, of which 10 aneurysms were unruptured and 12 were ruptured. Aneurysmal sizes and angles between the parent artery and each of the two daughter arteries were measured. Furthermore, aneurysms were classified into two types based on neck location. Thus, when the neck was located on the extension of the midline of the parent artery, it was defined as a classical neck type aneurysm, and when it was not, it was defined as a deviating neck type aneurysm. There were 15 cases of deviating and 7 cases of classical neck type. Interestingly, in the deviating neck type, all the aneurysms existed on the side of the daughter arteries of which the angles between parent arteries were narrower, and in 93%, the sizes of the daughter arteries in which the neck existed were smaller compared with other daughter arteries.

Interhemispheric arachnoid cyst in the elderly: case report and review of the literature

BACKGROUND Preoperative differential diagnosis of interhemispheric cysts is sometimes difficult. CASE DESCRIPTION We recently experienced a case of symptomatic interhemispheric arachnoid cyst in a 62-year-old woman. We reviewed interhemispheric arachnoid cysts in the elderly and the management of symptomatic interhemispheric arachnoid cysts in elderly patients. Symptomatic interhemispheric arachnoid cysts in the elderly are predominantly located on the right side, have a long history of progressive symptomology, occur predominantly in females, and have no communication with the subarachnoid space. Interhemispheric arachnoid cysts are usually not associated with agenesis of the corpus callosum in elderly patients, whereas interhemispheric nonarachnoid cysts are usually associated with agenesis of the corpus callosum, which will be clearly demonstrated on magnetic resonance imaging. CONCLUSIONS It is highly possible that an interhemispheric cyst without agenesis of the corpus callosum in an adult is an arachnoid cyst.

The characteristics of the anterior communicating artery aneurysm complex by three-dimensional digital subtraction angiography.

To elucidate the three-dimensional structure of the anterior communicating artery complex, we performed three-dimensional digital subtraction angiography in anterior communicating (Acom) aneurysm cases. Eighteen patients (six male and 12 female) with Acom aneurysms were studied. The total number of aneurysms was 18, of which three were unruptured and 15 were ruptured. Aneurysmal sizes and angles between the parent artery and each of the two daughter arteries were measured. Two types were defined, based on the daughter arteries. When the sizes of the two daughter arteries were the same, they were defined as AA’ type, and when different, they were defined as AB type. Furthermore, aneurysms were classified into two types based on neck location. Thus, when the neck was located on the extension of the midline of the parent artery, it was defined as classical neck type, and when it was not, it was defined as deviating neck type. There were 11 cases of AA’ type and seven of AB type. In AA’ type all cases were of the classical neck type, and in AB type three cases were of the classical neck type and three were of the deviating neck type. In the deviating neck type, the necks were deviated to the smaller daughter arteries in all cases.

In vitro chemosensitivity test of human brain tumors using a three-dimensional organ culture with a collagen gel matrix

We evaluated the usefulness of anin vitro tumor organ culture system using a specialized collagen gel matrix derived from pig skin as a chemosensitivity test for human brain tumors. Two xenograft tumors derived from human glioblastoma and medulloblastoma were examined with this system and the results were compared with data obtained from a nude mouse assay. Xenograft tumors exhibitedin vivo-like three-dimensional growth on the collagen gel matrix and had increasing incorporation of tritiated (3H)thymidine for 2 weeks. Drug sensitivity, as measured by this assay at therapeutic peak plasma concentrations of anticancer drugs, corresponded with that measured with the nude mouse assay. Chemosensitivity of 16 surgical specimens of malignant brain tumors were also examined successfully by this collagen gel matrix (CGM) assay. When the highest inhibition rate in dose-inhibition curve was equal to or greater than 50%, the tumor was regarded to be sensitive to the agent. The efficacy rates in CGM assay for 16 lesions were 25.0% (4/16) for ACNU, 67.8% (11/16) for adriamycin, 31.3% (5/16) for cisplatin, and 67.8% (11/16) for etoposide. The CGM assay has advantages as a chemosensitivity test because of its simple procedure, rapidity, high rate of evaluable tumor growth, andin vivo-like three dimensional tumor growth. Our results indicate that the CGM assay is feasible to test the chemosensitivity of malignant brain tumors.