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Kiyohiro Houkin and Satoshi Kuroda

✓ The authors examine the quality of intraoperative photography in which digital recording technology, including a microdigital camera and digital video paired with an operating microscope, is used during neurosurgery. A microdigital camera developed for this purpose (1.4 million pixels) was attached to an operating microscope and used during surgery. The same surgical views with precisely the same optical conditions were taken through the microscope by using both a conventional 35-mm camera and the microdigital camera, and the quality of the final output was compared. In addition, the quality of the digital camera photographs was compared with the still photograph clipped from the digital video recording.

The quality of the photographs taken with a microdigital camera was superior to the quality of those obtained with the conventional 35-mm camera. The success rate of recording (what you see is what you get) was almost 100%. The quality of the still photographs clipped from the digital video was nearly equal to those taken with the digital camera. The microdigital camera system is superior to the conventional 35-mm camera in neurosurgery in terms of its success rate and the quality of the photography. It is also a space-saving system for storing the huge amount of data generated in the recording of surgical procedures, and the cost/performance ratio is superior to that of the conventional method. Digital technology including digital cameras and videos is very useful for clear recording of microsurgical procedures.

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Satoshi Ushikoshi, Kiyohiro Houkin, Fumio Itoh, Hisatoshi Saitoh, Michimasa Nozaki, Satoshi Kuroda and Hiroshi Abe

✓ The authors describe the case of a 69-year-old man with an intracerebral hemorrhage due to rupture of a nontraumatic aneurysm of the middle meningeal artery (MMA). The ipsilateral posterior cerebral artery (PCA) was occluded, and dural anastomoses developed as the main collateral pathway between the MMA and the cortical branch of the PCA, on which the aneurysm was located. It is considered that increased hemodynamic stress to the collateral pathway contributed to the formation of the aneurysm.

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Shusuke Yamamoto, Satoshi Hori, Daina Kashiwazaki, Naoki Akioka, Naoya Kuwayama and Satoshi Kuroda

OBJECTIVE

This study aimed to assess longitudinal changes in the collateral channels originating from the lenticulostriate artery (LSA), posterior communicating artery (PCoA), and anterior and posterior choroidal arteries (AChA and PChA, respectively) during disease progression and/or aging. The impact of collateral channels on onset type was also examined.

METHODS

This study included 71 involved hemispheres in 41 patients with moyamoya disease. The disease was categorized into 6 stages according to Suzuki’s angiographic staging system. The degree of development of each moyamoya vessel was categorized into 3 grades.

RESULTS

The LSA started to dilate in stage 2, showed the most prominent development in stage 3, and decreased in more advanced stages (p < 0.001). The AChA most notably developed in stage 3 and gradually shrank (p = 0.04). The PCoA started to dilate in stage 3 and showed the most prominent development in stage 4 (p = 0.03). The PChA started to dilate in stage 3 and showed the most prominent development in stages 4 to 5 (p < 0.001). Patient age was negatively related to LSA development (p = 0.01, R = 0.30) and was positively associated with the abnormal dilation and extension of the PCoA (p = 0.02, R = 0.28) and PChA (p < 0.001, R = 0.45). The PCoA, AChA, and PChA more distinctly developed in hemispheres with intracerebral or intraventricular hemorrhage than in hemispheres with ischemic stroke or transient ischemic attack (p < 0.001, p = 0.03, and p = 0.03, respectively).

CONCLUSIONS

This study suggests that the collateral channels through moyamoya vessels longitudinally shift from the anterior to posterior component during disease progression and aging, which may be closely related to the onset of hemorrhagic stroke in adult moyamoya disease.

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Kiyohiro Houkin, Hiroyasu Kamiyama, Satoshi Kuroda, Tatsuya Ishikawa, Akihiro Takahashi and Hiroshi Abe

✓ Reconstruction of the carotid artery by using a radial artery graft is a useful option that can produce reliable long-term patency for the surgical treatment of giant and/or large aneurysms of the cavernous and paraclinoid internal carotid artery (ICA).

During the past 10 years, 43 patients with intracavernous and paraclinoid giant aneurysms of the ICA have been treated by reconstruction of the ICA with radial artery grafts after ligation of the cervical ICA. The long-term patency of the grafted radial artery was evaluated over more than a 5-year period (mean 7.2 years) in 20 of these patients by using magnetic resonance angiography or conventional angiography. There was no late occlusion of the graft in any of these cases. Stenotic graft changes were observed in two cases.

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Mitsunori Matsumae, Akihiro Hirayama, Hideki Atsumi, Satoshi Yatsushiro and Kagayaki Kuroda

Object

New approaches for understanding CSF motion in healthy individuals and patients with hydrocephalus and Chiari malformation are presented. The velocity and the pressure gradient of CSF motion were determined using phase contrast (PC) MRI.

Methods

The authors examined 11 healthy control subjects and 2 patients (1 with hydrocephalus and 1 with Chiari malformation), using 4-dimensional PC (4D-PC) MRI and a newly developed computer analysis method that includes calculation of the pressure gradient from the velocity field. Sagittal slices including the center of the skull and coronal slices of the foramen of Monro and the third ventricle were used.

Results

In the ventricular system, mixing and swirling of the CSF was observed in the third ventricle. The velocity images showed that the CSF was pushed up and back down to the adjacent ventricle and then returned again to the third ventricle. The CSF traveled bidirectionally in the foramen of Monro and sylvian aqueduct. Around the choroid plexus in the lateral ventricle, the CSF motion was stagnant and the CSF pressure gradient was lower than at the other locations. An elevated pressure gradient was observed in the basal cistern of the subarachnoid space. Sagittal imaging showed that the more prominent pressure gradients originated around the cisterna magna and were transmitted in an upward direction. The coronal image showed a pressure gradient traveling from the central to the peripheral subarachnoid spaces that diminished markedly in the convexity of the cerebrum. The 2 patients, 1 with secondary hydrocephalus and 1 with Chiari malformation, were also examined.

Conclusions

The observed velocity and pressure gradient fields delineated the characteristics of the CSF motion and its similarities and differences among the healthy individuals and between them and the 2 patients. Although the present results did not provide general knowledge of CSF motion, the authors' method more comprehensively described the physiological properties of the CSF in the skull than conventional approaches that do not include measurements of pressure gradient fields.

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Jonathan J. Russin, Amir R. Dehdashti, Peter Vajkoczy, Satoshi Kuroda and Ying Mao

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Tomohide Hayashi, Seiji Yamamoto, Takeru Hamashima, Hisashi Mori, Masakiyo Sasahara and Satoshi Kuroda

OBJECTIVE

This study aimed to clarify the underlying mechanism of pathognomonic angiogenesis between the temporal muscle and neocortex after indirect bypass for moyamoya disease by shedding light on the role of platelet-derived growth factor receptor–α (PDGFRα) in angiogenesis.

METHODS

The gene for PDGFRα was systemically inactivated in adult mice (α-KO mice). The Pdgfra-preserving mice (Flox mice) and α-KO mice were exposed to bilateral common carotid artery stenosis (BCAS) by using microcoils. One week later the animals underwent encephalomyosynangiosis (EMS) on the right side. Cerebral blood flow (CBF) was serially measured using a laser Doppler flowmeter. Histological analysis was performed on the distribution of CD31-positive vessels and collagen deposit at 28 days after BCAS. Reverse transcription polymerase chain reaction (RT-PCR) was performed to assess the expression of collagen mRNA in the skin fibroblasts derived from Flox and α-KO mice.

RESULTS

BCAS significantly reduced CBF up to approximately 70% of the control level at 28 days after the onset. There was no significant difference in CBF between Flox and α-KO mice. EMS significantly enhanced the improvement of CBF on the ipsilateral side of Flox mice, but not α-KO mice. EMS significantly induced the development of CD31-positive vessels in both the neocortex and temporal muscle on the ipsilateral side of Flox mice, but not α-KO mice. Deposition of collagen was distinctly observed between them in Flox mice, but not α-KO mice. Expression of mRNA of collagen type 1 alpha 1 (Col1a1) and collagen type 3 alpha 1 (Col3a1) was significantly downregulated in the skin fibroblasts from α-KO mice.

CONCLUSIONS

This is the first study that denotes the role of a specific growth factor in angiogenesis after EMS for moyamoya disease by inactivating its gene in mice. The findings strongly suggest that PDGFRα signal may play an important role in developing spontaneous angiogenesis between the temporal muscle and neocortex after EMS in moyamoya disease.

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Daina Kashiwazaki, Naoki Akioka, Naoya Kuwayama, Tomohide Hayashi, Kyo Noguchi, Kortaro Tanaka and Satoshi Kuroda

OBJECTIVE

The roles of endothelial progenitor cells (EPCs) in the development of carotid plaque are still obscure. This study aimed to clarify this by assessing the histological findings of specimens obtained from carotid endarterectomy.

METHODS

This study included 34 patients who underwent carotid endarterectomy. MR imaging was performed to semiquantitatively analyze the components of the carotid plaques in all patients. The surgical specimens were subjected to immunohistochemistry. The distributions of the CD34-, CD133-, VEGF-2R–positive cells in the carotid plaques were precisely analyzed, and their number was quantified. Simultaneously, the CD34-positive microvessels were localized.

RESULTS

The plaque component was judged as lipid-rich plaque in 19 patients, intraplaque hemorrhage (IPH) in 11 patients, and fibrous plaque in 4 patients. The CD34-positive microvessels were densely distributed in the plaque shoulder and interface-to-media regions. The CD34-, CD133-, and VEGF-2R–positive cells were mainly localized around the CD34-positive microvessels. The number of CD34-positive microvessels significantly correlated with the number of CD34-, CD133-, and VEGF-2R–positive cells (R = 0.308, p = 0.009; R = 0.324, p = 0.006; and R = 0.296, p = 0.013, respectively). Vulnerable plaques (lipid-rich and IPH) had significantly higher numbers of the CD34-positive microvessels (p = 0.007) and CD34-, CD133-, and VEGF-2R–positive cells than fibrous plaques (p = 0.031, p = 0.013, and p = 0.002).

CONCLUSIONS

These findings strongly suggest that neovascularization in the plaque shoulder and interface-to-media regions may play a key role in delivering EPCs from the peripheral blood to the carotid plaque, promoting the growth of carotid plaque. Furthermore, the invaded EPCs, especially the CD133-positive immature EPCs, may be related to plaque vulnerability.

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Haruto Uchino, Daina Kashiwazaki, Naoki Akioka, Masaki Koh, Naoya Kuwayama, Kiyohiro Houkin and Satoshi Kuroda

OBJECTIVE

In this study the authors aimed to describe clinical features, surgical techniques, and long-term outcomes of repeat bypass surgery required for a certain subset of patients with moyamoya disease.

METHODS

The authors retrospectively reviewed a total of 22 repeat bypass surgeries for 20 patients (age range 1–69 years) performed during the last 20 years at their institutions. The patients were classified into 2 groups. Group A included 10 patients who underwent repeat bypass surgery for anterior circulation due to insufficient revascularization on the ipsilateral side. Group B included 10 patients who underwent repeat bypass surgery for posterior circulation due to the involvement of the posterior cerebral artery (PCA) after successful initial surgery for anterior circulation.

RESULTS

Preoperative symptoms included headache in 3 patients, transient ischemic attack in 10, cerebral infarction in 3, and intracranial hemorrhage in 4 patients. Intervals between the initial bypass surgery and repeat bypass surgery were 0.3–30 years (median 3 years). In group A, superficial temporal artery to middle cerebral artery (MCA) anastomosis and indirect bypass were performed on 7 hemispheres. Only indirect bypass was performed on 3 hemispheres because of the lack of suitable donor or recipient arteries. In group B, occipital artery (OA) to PCA anastomosis and indirect bypass were conducted on 4 hemispheres, and OA-MCA anastomosis and indirect bypass on 1 hemisphere. Only indirect bypass was conducted on 7 hemispheres because of the lack of suitable recipient arteries. All 22 repeat bypass surgeries were successfully conducted. During follow-up periods (median 4 years), none of the patients suffered repeat stroke except 1 patient who died of recurrent intracerebral hemorrhage 3 years after repeat bypass surgery for anterior circulation.

CONCLUSIONS

Repeat bypass surgery was feasible and effective to reduce further incidence of headache attack, transient ischemic attack, and ischemic/hemorrhagic stroke in moyamoya disease patients. Through precise radiological analysis, surgical procedures should be planned to yield maximal therapeutic effects.

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Hiroshi Yasuda, Satoshi Kuroda, Hideo Shichinohe, Shintaro Kamei, Ryoichi Kawamura and Yoshinobu Iwasaki

Object

In this study the authors' aim was to assess whether fibrin matrix could act as an injectable, valuable scaffold in bone marrow stromal cell (BMSC) transplantation for injured CNS tissue.

Methods

Both clotting time and 3D structure of fibrin matrix were analyzed with various concentrations of fibrinogen and CaCl2. The BMSCs were harvested from green fluorescent protein–transgenic mice and cultured. A cortical lesion was produced in rats by application of a very cold rod to the right cerebral hemisphere. The BMSCs, fibrin matrix, or BMSC–fibrin matrix complex was transplanted into the lesion though a small bur hole 7 days after the insult. Using immunohistochemical analysis, the authors evaluated the survival, migration, and differentiation of the transplanted cells 4 weeks after transplantation.

Results

Based on in vitro observations, the concentrations of fibrinogen and CaCl2 were fixed at 2.5 mg/ml and 2 μM in animal experiments, respectively. Fibrin matrix almost completely disappeared 4 weeks after transplantation. However, immunohistochemical analysis revealed that fibrin matrix exclusively enhanced the retention of the transplanted cells within the lesion, migration toward the lesion boundary zone, and differentiation into the neurons and perivascular cells.

Conclusions

Injectable fibrin matrix enhanced the survival, migration, and differentiation of the BMSCs transplanted into the cortical lesion in rats. The authors believe that it is one of the promising candidates for a potential, minimally invasive scaffold for CNS disorders. The present findings strongly suggest that such a strategy of tissue engineering could be a therapeutic option for CNS regeneration in patients with CNS injuries.