Yukitomo Ishi

Change in 18F-Fluoromisonidazole PET Is an Early Predictor of the Prognosis in the Patients with Recurrent High-Grade Glioma Receiving Bevacizumab Treatment.

Background Bevacizumab (BEV), a humanized monoclonal antibody, become a currently important chemotherapeutic option for the patients with recurrent glioma. The aim of this retrospective study is to investigate whether 18F-Fluoromisonidazole (FMISO) PET have the potential to detect BEV-resistant gliomas in the early-stage. Methods We reviewed the FMISO PET and MRI appearances before and 3 to 4 courses after BEV treatment on 18 recurrent glioma patients. FMISO accumulation was assessed by visual inspection and semi-quantitative values which were tumor-to-normal (T/N) ratio and hypoxic volume. MRI responses were evaluated based on RANO (Response Assessment in Neuro-Oncology) criteria. The prognostic analysis was performed in relation to the response assessment by FMISO PET and MRI using overall survival (OS) after BEV application. Results After BEV application, MRI revealed partial response in 14 of 18 patients (78%), of which 9 patients also demonstrated decreased FMISO accumulation. These 9 patients (50%) were classified as “MRI-FMISO double responder”. As for the other 5 patients (28%), FMISO accumulation volumes increased or remained stable after BEV treatment although partial responses were achieved on MRI. Therefore, these cases were classified as “MRI-only responder”. The remaining 4 patients (22%) did not show treatment response on FMISO PET or MRI (“non-responder”). MRI-FMISO double responders showed significantly longer OS than that in other groups (median 12.4 vs 5.7 months; P < 0.001), whereas there were no overall survival difference between MRI-only responders and non-responders (median OS, 5.7 and 4.8 months; P = 0.58). Among the pre-treatment clinical factors, high FMISO T/N ratio was a significant prognostic factor of overall survival in these patients under the assessment of Cox proportional hazard model. Conclusions Recurrent gliomas with decreasing FMISO accumulation after short-term BEV application could derive a survival benefit from BEV treatment. Change in FMISO PET appearance can identify BEV-resistant gliomas in early-stage regardless of MRI findings in a comprehensible way.

Case Report: Trigeminal Neuralgia Caused by a Minute Meningioma with Hyperostosed Suprameatal Tubercle

Cerebellopontine angle tumors might occasionally provoke trigeminal neuralgia but are usually large enough to be diagnosed radiographically. We present a case of trigeminal neuralgia caused by a very small meningioma covering the suprameatal tubercle that displayed hyperostosis at the entrance of Meckels cave and was not obvious on routine magnetic resonance (MR) images. A 72-year-old woman with intractable trigeminal neuralgia in the left V3 territory was referred to our institution. Preoperative imaging studies revealed that the left trigeminal nerve was medially distorted at the entrance of Meckels cave by a laterally seated bone bulge covered by a minute enhanced lesion. Trigeminal nerve decompression surgery was performed via a retrosigmoid intradural suprameatal approach. We found a small meningioma that had compressed and flattened the trigeminal nerve root at the entrance of Meckels cave, which was grossly and totally removed by suprameatal tubercle resection. There was no vascular compression of the trigeminal nerve root. The trigeminal neuralgia ceased completely after the operation. Accurate preoperative determination of the causative pathologies is essential to achieve adequate surgical results after microvascular decompression for neurovascular compression syndrome. Because conventional MR sequences are inadequate for the precise interpretation of complex neurovascular anatomy in the cerebellopontine angle and such small tumors can be overlooked on routine MR studies, high-resolution thin-slice MR examinations and careful radiological interpretations are required for correct diagnosis and treatment.

Successful Removal of a Metastatic Gastrointestinal Stromal Tumor in the Craniovertebral Junction using an Occipital Artery to Posterior Inferior Cerebellar Artery Bypass.

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms arising from the gastrointestinal tract. The authors present a case of the successful removal of a metastatic GIST in the craniovertebral junction, using an occipital artery to posterior inferior cerebellar artery (OA-PICA) bypass. The patient is a 54-year-old male who underwent his first surgery for a small-bowel tumor at the age of 45 and was diagnosed with GIST. Nine years after his primary diagnosis, the patient suffered from severe neck pain. MRI demonstrated a large demarcated mass adjacent to the right atlas. The right vertebral artery (VA), completely engulfed by the tumor, showed a narrowing and ended in the PICA. Poor collateral blood supply in the right PICA territory was presumed. To prevent ischemic complications, an OA-PICA bypass was performed prior to the tumor resection. After the OA-PICA bypass, the tumor associated with the right VA was successfully removed, and the patient was discharged without any neurological deficits.

[Risk Factors for Adverse Events after Implantation of BCNU Wafers in High-grade Gliomas].

BACKGROUND In Japan, patients with malignant glioma have been treated with BCNU wafers (Gliadel®) since January 2013. Several adverse events(AEs)associated with implantation of BCNU wafers, including cerebral edema or cyst formation, are recognized. Here, we report a retrospective review of the experience with implantation of BCNU wafers in our institutions and our findings regarding the risk factors for the AEs. METHODS We reviewed the records of patients with malignant glioma who were implanted with BCNU wafers between April 2013 and September 2014. Their AEs were examined clinically and radiologically and evaluated according to Common Terminology Criteria for Adverse Events (CTCAE) grading. For investigating the association between risk factors and incidence of AEs, histological diagnosis, extent of resection, and period of BCNU wafers implantation surgery were selected as possible risk factors. RESULTS Twenty-one patients were included in this investigation. There were no associations among incidence of AEs and histological diagnosis or extent of tumor resection. However, regarding the period of BCNU wafers implantation, additional resection for newly diagnosed tumors and resection for recurrent tumors tended to increase the rate and severity of AEs, especially cerebral edema, compared to primary resection. CONCLUSION In cases of BCNU wafers implantation, the incidence and degree of AEs might increase if additional resection for newly diagnosed tumors or resection for recurrent tumors is performed. Our investigation revealed that AEs associated with implantation of BCNU wafers tend to occur in the repeated glioma surgery.

[Efficacy of Stent-Assisted Coil Embolization for a Dissecting Aneurysm of the Cervical Internal Carotid Artery Caused by a Systemic Vascular Disease: A Case Report].

Systemic vascular diseases such as fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan syndrome, and Behçets disease are known to cause spontaneous dissecting aneurysms of the cervical internal carotid artery. These diseases are generally associated with vascular fragility; therefore, invasive treatments are avoided in many cases of dissecting aneurysms, and a conservative approach is used for the primary disease. Surgical or intravascular treatment may be chosen when aneurysms are progressive or are associated with a high risk of hemorrhage; however, there is no consensus on which treatment is better. We report a case of a dissecting aneurysm of the cervical internal carotid artery in a patient with suspected Behçets disease, which was treated using stent-assisted coil embolization. A man in his 40s, with suspected Behçets disease, presented with an enlarged dissecting aneurysm of the right cervical internal carotid artery. The lesion was present for approximately 10 years. We performed stent-assisted coil embolization for the lesion. Post-surgery, no aneurysms were detected with carotid artery echography. Our case report suggests that stent-assisted coil embolization is a promising treatment for dissecting aneurysms of the cervical internal carotid artery. In addition, the procedure demonstrates the utility of carotid artery echograms for examining recanalization after stent-assisted coil embolization.

Endoscopic transsphenoidal surgery using pedicle vascularized nasoseptal flap for cholesterol granuloma in petrous apex: A technical note

BACKGROUND Compared with surgical resection, endoscopic transsphenoidal surgery (TSS) for cholesterol granuloma (CG) in the petrous apex (PA) is associated with local recurrence due to obstruction of the drainage route. We present a detailed procedure of an endoscopic TSS using pedicle vascularized nasoseptal flap (PVNF). METHODS A 40-year-old woman with a history of repeated surgery for left tympanitis was referred to our institution. Neurological examination revealed severe hearing loss in the left ear. Radiologic examination presented a round mass in the left PA and significant fluid collection in the mastoid air cells of the left temporal bone. CG was strongly suspected, and endoscopic TSS using PVNF was performed. Prior to endoscopic drainage, a PVNF was harvested from the mucosa of the ipsilateral nasal septum, with an attempt to preserve the sphenopalatine artery in the flap. Following this, puncture and adequate irrigation of the lesion was performed by endoscopic TSS, with neuro-navigation system assistance; the apex of PVNF was then placed into the lesion to prevent the obstruction of the drainage route. An absorbable polyglycolic acid sheet and fibrin glue were applied on the flap to prevent spontaneous deviation from the lesion. RESULTS The patient was discharged without any further neurological complications. Eight-month postoperative computed tomography images showed no recurrence; the drainage route was patent and the fluid collection in the left mastoid air cells was resolved. Moreover, hearing loss was improved. CONCLUSIONS Endoscopic TSS using PVNF may be one of available surgical options for PACG.

Application of endoscopic ultrasonography to intraventricular lesions

BackgroundAnatomical landmarks such as choroid plexus and foramen of Monro are very important to undergo intraventricular surgery safely and effectually. These landmarks would be unclear in cases with a huge cyst or repeat surgery. We report the usability and precautions to apply a bronchoscope with an ultrasonic convex probe to intraventricular surgery.MethodsTwo patients diagnosed with obstructive hydrocephalus, one with a large cyst and the other with recurrent craniopharyngioma in the third ventricle, were applied to the EBUS system.ResultsIn both patients, the EBUS system was applied safely, and lesions beyond the wall of ventricles or the cyst were visible. Color Doppler ultrasonography detected choroid plexus and internal cerebral veins. Furthermore, we performed real-time ultrasound-guided cyst puncture safely on the case with a large cyst. The most important precaution is that the curved portion of the EBUS system is too long to be bent within cerebral ventricles.ConclusionsThe new EBUS system with an ultrasonic convex probe is a novel and effectual device to perform intraventricular surgery.

[Rapid spontaneous resolution of acute epidural hematoma in an infant:a case report].

Resolution of acute epidural hematoma (AEDH) usually takes several weeks. The authors present an infantile case of AEDH that rapidly decreased within a day and review the literature. A 7-month-old boy fell from a height of approximately one meter and sustained a head injury. On presentation, a skull fracture in the right temporoparietal region was found and a small AEDH was observed on computed tomography (CT) 1 hr after the injury. He was transferred to our institute because of growing AEDH, shown by CT images taken 3 hr after the injury. We decided to treat him conservatively as he did not exhibit any neurological deficits on admission. CT images 24hr after the injury showed significant reduction of the AEDH. There was also an increase in the subcutaneous hematoma. Follow-up CT images did not show enlargement of the AEDH. The patient was discharged with no neurological deficits 3 days after admission. Rapid resolution of the AEDH might have been due to transmigration of the hematoma into the epicranial layer through the fracture gap.

[Successful acute endovascular therapy of cerebral embolism for a patient with ventricular assist device: a case report].

The number of patients with a ventricular assist device(VAD)will increase with the spread of heart transplantation in Japan. On the other hand, it is likely that VADs could cause cerebral embolism. However, there are few reports about endovascular therapy for intracranial embolic infarction from VAD. The authors report successful acute endovascular therapy for cerebral embolism. A 19-year-old woman with a VAD who received anti-coagulant treatment by warfarin sodium presented disturbance of consciousness and right hemiparesis. CT scan showed early CT sign in the left middle cerebral artery (MCA) area. 3D-CTA demonstrated occlusion of the left MCA and basilar artery (BA). We first performed endovascular recanalization in the left MCA, because IV tPA was ineligible. The left MCA was recanalized with TICI 2b perfusion and her symptoms were significantly improved. The treatment of the VAD patient reveals important issues. First, the femoral puncture requires ultrasound due to pulseless femoral artery. Second, the access route is an intact artery because of the anatomy of the VAD. Third, even if the patient has a hemorrhagic complication by intervention, the patient must be kept on anti-coagulant treatment because the VAD requires it. Careful consideration should be given to recanalization of occlusive vessels.