Saya Ozaki

Utility of three-dimensional computed tomography for anatomical assistance in endoscopic endonasal transsphenoidal surgery

Endoscopic endonasal transsphenoidal surgery (ETSS) has been widely applied to pituitary adenomas. However, anatomical orientation is difficult when structures of the sphenoidal sinus are complicated. This study investigated the usefulness of three-dimensional computed tomography (3D-CT) modeling in planning surgical procedures for ETSS and providing anatomical guidance during surgery. CT data from 99 consecutive patients with pituitary adenoma treated between January 2008 and March 2014 were used to reconstruct 3D-CT models. Based on these images, the architecture of sphenoidal sinus, particularly structures surrounding the sellar floor, was visualized for preoperative simulation of surgical procedures. These 3D-CT images were also compared to surgical views during ETSS to evaluate applicability of the images. These models clearly demonstrated the morphology of the nasal cavity and structures of the sphenoidal sinus, including bony prominences of the internal carotid arteries (ICAs) and optic canals by successively eliminating sphenoidal structures. The 3D-CT images permitted determination of the maximum marginal line of the opening of the sellar floor by presenting vital structures such as ICAs and optic canals. With this 3D-CT model, the surgeon could access the sella more easily, open the floor widely enough for each individual patient, and resect the tumor maximally without complications. Preoperative 3D-CT models distinctly visualized the optic canals, bilateral ICAs, and complicated structures of sphenoidal septa. The 3D-CT images were useful for preoperative planning and as a road map during endoscopic surgery for pituitary adenoma, facilitating maximum tumor resection without complications.

[Pathogenesis of in-stent thrombosis after carotid artery stenting].

BACKGROUND AND PURPOSE In-stent thrombosis (IST) after carotid artery stenting (CAS) is a rare complication that can lead to severe thromboembolic events. The purpose of this study was to investigate the pathogenesis of IST after CAS. PATIENTS AND METHODS A total of 101 patients underwent CAS from January 2006 to September 2013 at our hospital. Five of these patients experienced IST. We reviewed their clinical course and treatment. In addition, we compared various parameters, including basal disease, preceding anti-platelet therapy, rate of stenosis, length of stenosis, preoperative examination, type of stent, length of stent, post dilatation, and postoperative examination, between the IST and the non-IST groups. OUTCOME All cases in the IST group had low echoic plaque and open cell stent, and all thrombi were located at the dorsal side of the internal carotid artery and the distal side of the stent flexion. Four cases without neurological symptoms were found to have resolution of IST at 3-6 weeks after CAS with anticoagulant therapy. One case had symptomatic thromboembolism at 1 month after CAS, and the thrombus was removed along with the stent due to growth of the thrombus despite anticoagulant therapy. No significant differences were observed between the IST and non-IST groups with regard to the factors described in the methods section. CONCLUSIONS This study did not identify factors related to IST. We hypothesize that soft plaque can easily protuberate in the context of a stent with a large cell and that protrusion plaque may increase the risk of thrombus formation in combination with turbulent flow at the site of stent flexion. Further investigation in a larger number of patients is needed to clarify the risk factors related to IST.

Usefulness of cervical computed tomography and magnetic resonance imaging for rapid diagnosis of crowned dens syndrome: A case report and review of the literature

Highlights • We report a patient with crowned dens syndrome dramatically improved following treatment with nonsteroidal anti-inflammatory medication.• This condition should be considered in the differential diagnosis of a possible etiology for fever, headache and cervical pain of unknown origin.• The rapid diagnosis of crowned dense syndrome using CT and MRI can prevent invasive, expensive and useless investigations.• It was very interesting that the soft tissue surrounding the odontoid process was hyperintense on MR T2-weighted imaging with fat suppression.• This is the first report of making reference to MRI findings of crowned dens syndrome.

Plasma thrombin-cleaved osteopontin as a potential biomarker of acute atherothrombotic ischemic stroke.

We investigated whether thrombin-cleaved osteopontin N-terminal is useful as a blood biomarker of acute atherothrombotic ischemic stroke. Acute ischemic stroke patients were prospectively evaluated with brain magnetic resonance imaging and cardiac evaluations for etiological diagnosis according to the Trial of Org 10172 in Acute Stroke Treatment classification. They were divided into the atherothrombotic and non-atherothrombotic groups. Thrombin-cleaved osteopontin N-terminal, osteopontin, matrix metalloproteinase-9, S100B, C-reactive protein and D-dimer levels were measured from blood samples collected at admission. After excluding patients who met the exclusion criteria or had stroke of other/undetermined etiology, 60 of the 100 patients initially enrolled were included in the final analysis. The ischemic stroke subtypes were atherothrombotic (n=28, 46.7%), cardioembolic (n=19, 31.7%) and lacunar (n=13, 21.7%). Thrombin-cleaved osteopontin N-terminal and matrix metalloproteinase-9 levels were significantly higher in the atherothrombotic than in the non-atherothrombotic group (median (interquartile range): 5.83  (0.0–8.6 ) vs. 0.0  (0.0–3.3) pmol l−1, P=0.03 and 544   (322–749 ) vs. 343   (254–485) ng ml−1, P=0.01, respectively). After adjustment for the prevalence of hypertension, diabetes and dyslipidemia, thrombin-cleaved osteopontin N-terminal levels of >5.47 pmol l−1 (odds ratio, 16.81; 95% confidence interval, 3.53–80.10) and matrix metalloproteinase-9 levels of >605.5 ng ml−1 (6.59; 1.77–24.60) were identified as independent predictors of atherothrombosis. Within 3 h from stroke onset, only thrombin-cleaved osteopontin N-terminal independently predicted atherothrombosis and thus may add valuable, time-sensitive diagnostic information in the early evaluation of ischemic stroke, especially the atherothrombotic subtype.

Importance of perioperative management for emergency carotid artery stenting within 24 h after intravenous thrombolysis for acute ischemic stroke: Case report

Highlights • We report a patient treated successfully via endovascular surgery within 24 h after intravenous thrombolysis using recombinant tissue plasminogen activator for acute cervical internal carotid artery occlusion.• Emergency carotid artery stenting for the acute internal carotid artery occlusion may be considered a safe procedure in preventing early stroke recurrence in selected patients.• When trying to perform emergency carotid artery stenting within 24 h after intravenous recombinant tissue plasminogen activator administration, several issues require attention, such as the decisions regarding the type of stent and embolic protection device, the selection of antiplatelet therapy and the methods of preventing hyper perfusion syndrome.• We administered aspirin and clopidogrel for the prevention of subacute thrombosis, and we used dexmedetomidine for preventing hyperperfusion syndrome, so that we also obtained a good result.

Identification of characteristic features of pineal germinoma that enhance accuracy of preoperative differentiation in pineal region tumors: its significance on optimum surgical treatment

The aim of the study is to identify characteristic features of pineal germinoma that enhance preoperative accuracy in differentiating germinoma from other pineal region tumors. Twenty-one consecutive patients with pineal region tumors were enrolled. In all patients, tumor resection was performed to verify the histology. Clinical records including upward gaze palsy of Parinaud’s syndrome and neuroimaging were analyzed. In addition, we evaluated the relationship between magnetic resonance imaging (MRI) findings and tumor progression patterns in pineal germinoma. Among 21 patients, 15 patients were diagnosed with germ cell tumor, 4 with pineal parenchymal cell tumor, and 2 with meningioma. Upward gaze palsy was seen in 11 patients; nine had pure germinomas and two had mixed germ cell tumors. These tumors occupied the pineal region with extension to the area of the mesodiencephalic junction (MDJ) and the bi-epithalamic area between the bilateral pulvinar and the third ventricle. Tumor involvement of the former area could cause upward gaze palsy by insulting the rostral interstitial nucleus of the medial longitudinal fasciculus located in the MDJ area. Tumor invasion into the latter area is commonly seen as a cardioid-shaped tumor as the tumor image on the axial MRI view. Upward gaze palsy and a cardioid-shaped tumor image on the axial MRI views were demonstrated to be specific features of pineal pure germinoma. It is suggested that combination of both features may become useful tools to preoperatively differentiate germinoma from other pineal tumors, resulting in achievement of the optimum treatment of pineal region tumors.

[A Case of ECA-MCA Double Anastomoses for Hemorrhagic Type of Twig-Like MCA].

Herein, we describe the case of a superficial temporal artery(STA)- and occipital artery (OA)-middle cerebral artery (MCA) double anastomoses that we performed to treat a hemorrhagic twig-like MCA. A 55-year-old man presented to our hospital for investigation of an incidentally identified left MCA occlusion. Left cerebral angiography revealed a twig-like MCA. The (123)I-IMP-single photon emission computed tomography( SPECT) demonstrated no reduction in the cerebral blood flow (CBF), so the patient was initially observed with no treatment. Three months later, he was readmitted with a disturbance of consciousness. The cranial computed tomography revealed a subcortical hemorrhage in the left frontotemporal region and a subdural hematoma. The hematoma was removed via emergency craniotomy. The abnormal vessels were identified and resected, but the parietal branch of the STA was damaged during the skin incision. The histological examination did not reveal the marked fibrous thickening of the intima or wavy internal elastic lamina typically seen with Moyamoya disease. Six months after the initial surgery, a STA-MCA bypass surgery was planned to prevent a future hemorrhage by reducing the hemodynamic overload of the twig-like MCA and improving the cerebral ischemia in the MCA territory that was detected on the preoperative SPECT. However, the parietal branch of the left STA had been injured during the first operation, so we performed a double anastomoses to the MCA using the frontal branch of the STA and the OA. The patients postoperative course was uneventful and he was discharged 2 weeks after surgery. The follow-up study performed 1 year postoperatively demonstrated no evidence of cerebral infarction and revealed an improvement in the resting CBF and vascular reactivity in the left cerebral hemisphere. No subsequent cerebrovascular events have occurred in this patient during the 7 years since the double anastomoses surgery. Direct bypass for flow conversion from the internal carotid artery to the external carotid artery can be an indispensable treatment for patients with a hemorrhagic twig-like MCA.

[Hemorrhagic Adult Unilateral Moyamoya Disease with Multiple Unruptured Intracranial Aneurysms: A Case Report].

Adult unilateral moyamoya disease with intracranial aneurysm is frequently reported in the literature, but there is much variation in its treatment. In this case report, we describe the time course and treatment regimen of a patient with moyamoya disease and review the literature regarding moyamoya disease with intracranial aneurysm. A 64-year-old man had untreated intracranial aneurysm and unilateral moyamoya disease for 10 years. He presented with sudden-onset right hemiparesis and aphasia due to a subcortical hemorrhage. He was admitted to the local neurosurgical unit, and upon resolution of symptoms, he was admitted to our hospital. A cerebral angiogram revealed the champagne bottleneck sign of the left carotid artery and obliteration of the top of the left intracranial carotid artery with a moyamoya phenomenon. Two unruptured intracranial aneurysms were identified in the anterior communicating artery(Acom A) and the right intracranial carotid artery(C3). We performed superficial temporal artery-middle cerebral artery anastomosis followed by aneurysmal neck clipping of the Acom A aneurysm. Postoperative imaging showed no new ischemic damage and improved cerebral blood flow. Although the patient experienced temporal worsening of aphasia, his function recovered a few months later and he was able to resume his normal daily life activities. The combination of direct bypass surgery and aneurysmal neck clipping might be a therapeutic option for hemorrhagic unilateral moyamoya disease with unruptured intracranial aneurysm.

Significance of Glioma Stem-Like Cells in the Tumor Periphery That Express High Levels of CD44 in Tumor Invasion, Early Progression, and Poor Prognosis in Glioblastoma

Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor and a subpopulation of glioma stem-like cells (GSCs) is likely responsible for the invariable recurrence following maximum resection and chemoradiotherapy. As most GSCs that are located in the perivascular and perinecrotic niches should be removed during tumor resection, it is very important to know where surviving GSCs are localized. Here, we investigated the existence and functions of GSCs in the tumor periphery, which is considered to constitute the invasion niche for GSCs in GBM, by analyzing expression of stem cell markers and stem cell-related molecules and measuring particular activities of cultured GSCs. In addition, the relationship between GSCs expressing particular stem cell markers and pathological features on MRI and prognosis in GBM patients was analyzed. We showed that GSCs that express high levels of CD44 are present in the tumor periphery. We also found that vascular endothelial growth factor (VEGF) is characteristically expressed at a high level in the tumor periphery. Cultured GSCs obtained from the tumor periphery were highly invasive and have enhanced migration phenotype, both of which were markedly inhibited by CD44 knockdown. Higher expression of CD44 in the tumor periphery than in the core was correlated with a highly invasive feature on MRI and was associated with early tumor progression and worse survival, whereas lower expression of CD44 in the tumor periphery corresponded to low invasion and was associated with longer survival. The low invasion type on MRI tended to show high levels of VEGF expression in the tumor periphery, thus presenting the tumor with high proliferative activity. These results imply the significance of GSCs with high levels of CD44 expression in the tumor periphery compared to the core, not only in tumor invasion but also rapid tumor progression and short survival in patients with GBM.

Significance of human chorionic gonadotropin as a predictor of resistance to standard chemo-radiotherapy for pure germinoma

Intracranial pure germinomas in children generally respond well to standard chemo-radiotherapy. However, some patients are refractory to standard therapy and require additional treatment. To investigate the characteristics of this subgroup, we retrospectively analyzed the clinical features and treatment outcomes of a cohort of 21 patients with intracranial pure germinomas who were diagnosed between April 2002 and December 2016 at Ehime University Hospital in Japan. Pure germinoma diagnosis was verified by histological examination of the tumor after surgery, and all patients received standard chemo-radiotherapy. A suite of clinical features, including neuroimaging, human chorionic gonadotropin-β subunit (HCG-β), and α-fetoprotein (AFP) in the cerebrospinal fluid (CSF), as well as immunohistochemical expression of HCG-β, AFP, and Ki-67 in the tumor tissue were analyzed. Nineteen of the 21 patients had a complete response to standard chemo-radiotherapy without early recurrence of the tumors. Of these 19 patients, 17 did not have elevated CSF HCG-β levels or express HCG-β in the tumor tissue. However, the two patients who were refractory to standard therapy had elevated CSF HCG-β levels and expressed HCG-β in the tumor cells. These data suggest that patients with pure germinoma presenting with both an elevation of HCG-β in the CSF and HCG-β expression in the tumor tissue may be refractory to frontline treatment. These markers may predict aggressive germinoma and may ultimately facilitate the development of more effective treatment options.