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  • Author or Editor: Kampei Shimizu x
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Haruka Miyata, Hirohiko Imai, Hirokazu Koseki, Kampei Shimizu, Yu Abekura, Mieko Oka, Takakazu Kawamata, Tetsuya Matsuda, Kazuhiko Nozaki, Shuh Narumiya and Tomohiro Aoki

OBJECTIVE

Subarachnoid hemorrhage (SAH) has a poor outcome despite modern advancements in medical care. The development of a novel therapeutic strategy to prevent rupture of intracranial aneurysms (IAs) or a novel diagnostic marker to predict rupture-prone lesions is thus mandatory. Therefore, in the present study, the authors established a rat model in which IAs spontaneously rupture and examined this model to clarify histopathological features associated with rupture of lesions.

METHODS

Female Sprague Dawley rats were subjected to bilateral ovariectomy; the ligation of the left common carotid, the right external carotid, and the right pterygopalatine arteries; induced systemic hypertension; and the administration of a lysyl oxidase inhibitor.

RESULTS

Aneurysmal SAH occurred in one-third of manipulated animals and the locations of ruptured IAs were exclusively at a posterior or anterior communicating artery (PCoA/ACoA). Histopathological examination using ruptured IAs, rupture-prone IAs induced at a PCoA or ACoA, and IAs induced at an anterior cerebral artery–olfactory artery bifurcation that never ruptured revealed the formation of vasa vasorum as an event associated with rupture of IAs.

CONCLUSIONS

The authors propose the contribution of a structural change in an adventitia, i.e., vasa vasorum formation, to the rupture of IAs. Findings from this study provide important insights about the pathogenesis of IAs.

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Shoichi Tani, Hirotoshi Imamura, Katsunori Asai, Kampei Shimizu, Hidemitsu Adachi, So Tokunaga, Takayuki Funatsu, Keita Suzuki, Hiromasa Adachi, Shuhei Kawabata, Yuichi Matsui, Natsuhi Sasaki, Ryo Akiyama, Kazufumi Horiuchi, Chiaki Sakai and Nobuyuki Sakai

OBJECTIVE

The authors sought to compare methods of measurement for venous phase delay (VPD) or mean stump pressure (MSTP) to rank their potential to predict ischemic tolerance during balloon test occlusion in the internal carotid artery, exploring a more correlative and convenient way to measure cerebral blood flow (CBF) that could be utilized even in the acute phase or in institutions not adequately equipped to measure CBF during the test.

METHODS

X-ray angiography perfusion analysis using diagnostic digital subtraction angiography (DSA) equipment enables 1-step examination (without any room-to-room transfer of patients) to measure CBF, VPD, and MSTP completely simultaneously, which has not been accomplished by any previous perfusion studies.

RESULTS

This analysis was applied to 17 patients and resulted in successful estimation of all 3 parameters in each case. The average VPD of several cortical veins had a strong correlation with relative CBF (rCBF) between bilateral hemispheres with a correlation coefficient of 0.89443, a correlation as strong as that (0.90357) of the “approximate VPD,” which is interpreted based on the trend line of the scatterplot of the time to peak contrast opacification in cortical veins and their spatial positioning from the median sagittal plane. MSTP and classic visual determination of VPD have weaker correlation coefficients with rCBF (0.56119 and 0.70048, respectively). Overall, subjective visual determination in combination with the calculation of the trend line to estimate VPD provided a considerably strong correlation with rCBF (R = 0.86660) without any dedicated software or hardware.

CONCLUSIONS

VPD has a stronger correlation with rCBF than MSTP. rCBF could be successfully predicted on common DSA equipment, even by visual determination without expensive software, if the trend line is adopted for processing to estimate VPD.