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Background Many physicians consider aneurysmal wall enhancement (AWE) on high resolution-vessel wall imaging (HR-VWI) as an imaging biomarker of unstable unruptured intracranial aneurysms (UIAs). Objective To evaluate the clinical value of different AWE signal intensities (SIs) by assessing the correlation between the AWE SIs and surgical findings and rupture risk assessment tools. Methods Twenty-six patients with 34 aneurysms who underwent surgical clipping were included. The corrected AWE SI was calculated by comparing T1-weighted images with post-gadolinium enhanced T1-weighted images. The correlation of AWE with the population, hypertension, age, size of aneurysm, earlier subarachnoid hemorrhage from another aneurysm, site of aneurysm (PHASES) and earlier subarachnoid hemorrhage, location of the aneurysm, age >60 years, population, size of the aneurysm, shape of the aneurysm (ELAPSS) scores was evaluated using correlation and linear regression analysis. To quantify the surgical findings, the average color value of the aneurysms expressed in the CIELCh system was measured. Δh, color difference from yellow, was used for statistical analysis. Results The mean age of the patients and aneurysm size were 64.08 yr and 6.95 mm, respectively. The mean AWE SI, PHASES and ELAPSS scores, and Δh were 22.30, 8.41, 20.32, and 41.36, respectively. The coefficients of correlation of AWE SI with the PHASES and ELAPSS scores and Δh were 0.526, 0.563, and -0.431. We found that the AWE SI affected the PHASES (β = 0.430) and ELAPSS scores (β = 0.514) and Δh (β = -0.427) in simple linear regression analysis. Conclusion The AWE on HR-VWI was correlated with the PHASES and ELAPSS scores and the color. The stronger the AWE, the higher were the PHASES and ELAPSS scores and the more abnormal was the color. The AWE might indicate the degree of inflammation.

Background Thin-walled regions (TWRs) of aneurysm surfaces observed in microscopic surgery are thought to be vulnerable areas for growth and rupture of unruptured intracranial aneurysms (UIAs). Objective To identify hemodynamic features of TWRs of aneurysms by using computational fluid dynamics (CFD) analyses of unruptured middle cerebral artery bifurcation (MCAB) aneurysms. Methods Nine patients with 11 MCAB aneurysms were enrolled, and their TWRs were identified. CFD analysis was performed using 3 parameters: pressure, wall shear stress (WSS), and WSS divergence (WSSD). Each parameter was evaluated for its correspondence with TWR. Results Among 11 aneurysms, 15 TWRs were identified. Corresponding matches with CFD parameters (pressure, WSS, and WSSD) were 73.33, 46.67, and 86.67%, respectively. Conclusion WSSD, a hemodynamic parameter that accounts for both magnitude and directionality of WSS, showed the highest correspondence. High WSSD might correspond with TWR of intracranial aneurysms, which are likely high-risk areas for rupture.

Vertex epidural hematoma (VEDH) is a rare extradural hematoma and often misdiagnosed because of its variety of clinical symptoms and characteristic location. Determining optimal timing and technique for VEDH surgery is difficult because of its midline location and atypical clinical course. This study aims to understand the clinical manifestations and current treatment strategies for VEDH. We searched the published literature regarding VEDH through PubMed and Google Scholar, and individual patient data (IPD) were obtained from the eligible articles. A systematic review and IPD meta-analysis were conducted. In total, 70 patients’ individual participant data were gathered. Most patients were male (87%), and traffic-related accidents were the most common injury mechanism (49%). Approximately half the patients (47%) were neurologically intact with nonspecific symptoms such as headache, dizziness, and vomiting at admission. Motor weakness alone (17%) and symptoms related to cranial nerve dysfunction such as anosmia, blurred vision, or diplopia (10%) were also noted. A surgical approach was initially chosen for 20 patients (28%), but eventually chosen for 20 more (total 40, 57%) during the observation period (average delay to surgery, 5 days). Patients who received surgery showed significantly poorer neurological status and larger hematoma size. Totally, two patients (3%) died, but most patients (94%) had a favorable outcome scoring 5 on the Glasgow Outcome Scale. Although VEDH generally showed favorable outcomes, clinicians must be aware of a high rate of delayed neurological deterioration during the observation period, which can be fatal due to central downward herniation.

Objective Stent-assisted coil embolization of intracranial wide-necked aneurysm requires long-term postoperative antiplatelet therapy to prevent in-stent thrombosis. This study aimed to demonstrate results of temporary stent placement for coiling wide necked small intracranial aneurysms, which eliminated need for antiplatelet agents, and to discuss its feasibility and safety. Methods Data of 156 patients who underwent stent-assisted coil embolization between 2011 and 2014 were retrospectively analyzed. Thirteen cases of temporary stent-assisted coil embolization were included, and their clinical and radiological results were evaluated. Results The aneurysms treated were all unruptured except one case. All of them had wide neck with mean dome-to-neck ratio of 0.96 and were small-sized aneurysms with mean maximal diameter of 4.2 mm. There was no technical failure in retrieval of stent after completion of embolization of the target aneurysm. Immediate angiography revealed 11 complete and two partial embolization (one residual neck and one residual aneurysm). Two cases encountered thrombosis complication, and they were managed without neurological sequelae. The mean follow-up period was 43 months, angiographic follow-up revealed two cases with minor recurrence, and clinical outcome was good with modified Rankin scale score of 0. Conclusion Temporary stent-assisted coil embolization of small wide-necked intracranial aneurysm using fully retrievable stent appears safe and effective. Further application and evaluation of this technique in more cases with larger size aneurysm is warranted.

For most fractionated stereotactic radiosurgery treatment plans, daily imaging is not routinely performed, because there is little expectation that lesions will change significantly in the short term. However, here, we present the case of an abrupt increase and decrease in tumor volume during fractionated gamma knife radiosurgery (GKRS) for metastatic brain cancer. A 65-year-old man with a history of nephrectomy due to renal cell carcinoma was admitted to our hospital because of mild cognitive disorder and gait disturbance. An initial MRI of the brain demonstrated a 5 × 3 × 4.5 cm-sized, heterogeneously well-enhanced tumor with a large cystic component compressing the left thalamus and corpus callosum near the lateral ventricle. Owing to its large size and proximity to critical structures, we decided to perform 3 fractionated GKRSs over 3 consecutive days. After the first fraction of 9 Gy with 50% isodose, follow-up MRI the next day revealed an unexpected increase in tumor volume up to 30%. Therefore, the radiosurgical plan was adjusted, and GKRS was performed again using the same dose for the second fraction. The image taken on the third day showed rapid shrinkage of the tumor volume. This case shows that a tumor may change its shape and volume unexpectedly even during the short period of a fractionated GKRS session. Hence, for optimal fractionated GKRS treatment of tumors with the likelihood of an abrupt change in the short term, interval imaging should be considered.

Background Digital subtraction angiography is the gold standard to confirm complete removal of an arteriovenous malformation (AVM) nidus. However, the transfemoral approach requires specialized instrumentation and is cumbersome and difficult to perform with the patient in the prone or decubitus position. We report the use of intraoperative digital subtraction angiography (iDSA) with the transradial approach and examine its usefulness and safety. Materials and Methods We retrospectively reviewed clinical features, radiologic images, surgical findings, and iDSA findings of patients with AVM who underwent surgery for nidus removal. Transradial iDSA was performed within 30 minutes for patients who required angiographic confirmation after AVM resection. This procedure was simple with the radial arterial line for blood pressure monitoring used as digital subtraction angiography catheter access route. Results Transradial iDSA was performed in 23 patients. Twelve patients were not in the general supine position during neurosurgery; 7 patients were operated on in prone position, and 5 patients were operated on in the park bench position. Remnant nidus was identified by iDSA in 2 patients, and additional measures were required. Conclusions Intraoperative cerebral angiography during surgery for cerebral AVM could be performed safely via the transradial approach. This approach showed several merits in terms of easy access; no extra requirements, such as preoperative sheath implantation, anticoagulation during the surgery, or a radiolucent table; and usefulness in any surgical position. Further studies using this approach and comparison with the transfemoral approach are necessary.

Objective To report outcomes of cranioplasty (CP) with a customized three-dimensional (3D) titanium mesh plate and identify the relationship between various clinical variables and complications after CP. Methods Twenty patients who underwent surgery with customized 3D titanium mesh plates and had follow-up for >6 months from January 2015 to December 2017 were enrolled. Complications related to CP were retrospectively reviewed. Patients were divided into 2 groups (no complication group and complication group), and clinical variables related to complications were compared between the 2 groups. Correlation analysis was performed to identify the clinical variable significantly correlated with complications after CP with a customized 3D titanium mesh plate. Results Of 20 patients, 11 developed complications, including extrusion, intracranial infection, severe operative site pain, and wound dehiscence. Among the clinical variables, only the presence of a ventriculoperitoneal shunt was significantly correlated with the overall complication rate (odds ratio = 18.66; 95% confidence interval, 1.56–222.92; P = 0.021). Conclusions A customized 3D titanium mesh plate is associated with a lower risk of intracranial infection, but the rate of postoperative complications, mainly cosmetic problems, such as forehead mesh extrusion and dehiscence, was high at 55%. A ventriculoperitoneal shunt was significantly correlated with the overall complication rate after CP with a customized 3D titanium mesh plate.

Spontaneous vertebrobasilar dissecting aneurysm (VBD) is a very challenging disease with an unpredictable clinical course and controversies on treatment strategy. The present study reports radiological and clinical outcomes of stent-alone treatment (SAT) for VBD. Twenty-four VBDs treated with SAT are included in the present study. Clinical and angiographic data were reviewed retrospectively. A total of 24 lesions in 22 patients with a mean follow-up period of 16.21 months were included. Of the 24 individual lesions, 23 were intracranial vertebral artery lesions and 1 lesion was located in the basilar artery. There were six cases of ruptured dissections with the other cases having various symptoms. The immediate post-SAT angiographic outcomes included 5 lesions with good remodeling over 90% recovery and 19 poorly remodeled lesions. The latest angiographic outcomes included 17 cases of good remodeling (remodeling rate over 90%), 6 cases of poor remodeling (remodeling rate below 70%), and 1 case with morphological aggravation. The overlapping stent technique was used in seven cases and it was significantly associated with good angiographic results. None of the rupture cases underwent re-rupture post SAT. There was one case of a symptomatic complication of a femoral arteriovenous fistula. The SAT could be a feasible alternative for the treatment of VBD. The overlapping technique was significantly associated with good angiographic outcome. We expect that technological development of the intracranial stent will allow better procedural outcomes of SAT.

The authors report a case of in-stent restenosis (ISR) of the middle cerebral artery (MCA) following bare-metal stent (BMS) deployment and subsequent treatment using a drug-eluting stent (DES). This 65-year-old woman presented with frequent transient ischemic attacks. Initial studies revealed occlusion of the left internal carotid artery and severe stenosis of the right MCA with decreased cerebral perfusion in the bilateral MCA territories. Stent-assisted angioplasty of the right MCA was performed using a BMS, and satisfactory results were obtained with no complications. Six months after the procedure the patient presented with recurrent symptoms, and workups revealed ISR with decreased cerebral perfusion. A DES was successfully placed without complications. Follow-up studies at 3 and 8 months after retreatment showed sustained luminal integrity and cerebral perfusion. A combination of CT angiography and perfusion CT exhibited the anatomical results and hemodynamic status of the stenotic lesion, and these findings coincided with the patient's clinical symptoms and the results of conventional cerebral angiography. In-stent restenosis of the MCA after placement of a BMS can be treated using a DES. A combination of CT angiography and perfusion CT can be an alternative to conventional angiography. Low-profile devices with an amelioration of trackability are essential for the further incorporation of the DES into the field of endovascular neurosurgery. More clinical experiences and long-term follow-ups are mandatory to evaluate the safety, efficacy, and durability of the DES.

Intracranial endovascular procedures are less invasive and relatively safe; however, these procedures do carry a risk of complications, such as thromboembolization, arterial injury, and vessel occlusion. We present a case of carotid-cavernous fistula development secondary to injury of the cavernous segment of the internal carotid artery (ICA) during stent angioplasty and its treatment by transarterial coil embolization. Probable causes of this complication and its treatment method are discussed. To the best of our knowledge, this is the first report of such a case.

The authors report on a case of intravascular ultrasonography (IVUS)-guided stent angioplasty for iatrogenic extracranial vertebral artery (VA) dissection in a 49-year-old man after coil embolization for an unruptured aneurysm of the right posterior inferior cerebellar artery. Insignificant dissections occurred during the procedure. Postoperatively, the patient experienced gradually worsening posterior neck pain and headache, and follow-up angiography 8 months after the coil embolization revealed expansion of the dissection. The patient underwent stent angioplasty with IVUS guidance and his symptoms improved. To the authors' knowledge, this is the first report of IVUS-guided stent angioplasty of an extracranial VA dissection. It was safe and feasible to treat extracranial VA dissections with stent placement under IVUS guidance. Intravascular environments are in real time with IVUS, and this technique is useful in the confirmation of a true lumen and evaluation of appropriate stent apposition. More clinical experience with this technique is necessary and mandatory, and devices with smaller diameters with improved trackability are essential for further introduction of IVUS into the field of endovascular neurosurgery.

The leptin receptor-deficient db/db mouse is a rodent model of type 2 diabetes and obesity. Diabetes in db/db mice shows an age-dependent progression, with early insulin resistance followed by an insulin secretory defect resulting in profound hyperglycemia. However, there is insufficient data on agedependent changes of energy metabolism in db/db mice. We demonstrated an age-dependent decrease in the respiratory exchange ratio (RER), calculated by a ratio of VO2/VCO2, in db/db mice. The RER determined by indirect calorimetry, was 1.03 in db/db mice under 6 weeks of age, which were similar to those in heterozygote (db/+) and wild-type (+/+) mice. However, RER decreased from approximately 0.9 to 0.8 by 10 weeks of age and subsequently returned to approximately 0.9 at 22 weeks of age. The changes in RER were concurrent with the alterations in body weight and blood glucose level. However, other metabolic indicators such as glucose tolerance, changes in body fat mass, and urinary glucose levels, did not change with age. The results suggested that the energy source utilized in db/db mice changed with the age-related progression of diabetes.

We present 2 cases of complicated mechanical thrombectomy involving tandem cervical internal carotid artery and middle cerebral artery occlusion using the Solitaire FR stent and simultaneous carotid stent angioplasty. During the procedures, the Solitaire stents containing the thrombus were wedged into the open-cell carotid stents, which were already deployed for proximal flow restoration. We describe the methods used to avoid and overcome such complications.

Large to giant middle cerebral artery aneurysm is a challenging disease, especially when incorporating important perforating arteries. Surgical risk increases by perforator infarction and anatomical complexity. In this clinical setting, extensive consideration of surgical options is needed. The two cases described here were unruptured and had rather stable wall. Because of their large and giant size, hardness and incorporated arteries, it was not affordable to isolate them by means of clipping or trapping. The procedure as the alternative to conventional treatment modalities, extracranial-intracranial bypass followed by clipping of only the efferent artery successfully treated the aneurysms.

This study was performed to investigate the biological effects of boron neutron capture therapy (BNCT) on the testes and eyes in mice using HANARO Nuclear Reactor, Korea Atomic Energy Research Institute. BNCT relies on the high capacity of 10B in capturing thermal neutrons. Sodium borocaptate (BSH, 75 ppm, iv) and boronophenylalanine (BPA, 750 ppm, ip) have been used as the boron delivery agents. Mice were irradiated with neutron (flux: 1.036739E +09, Fluence 9.600200E+12) by lying flat pose for 30 (10 Gy) or 100 min (33 Gy) with or without boron carrier treatment. In 45 days of irradiation, histopathological changes of the testes and eyes were examined. Thirty-three Gy neutron irradiation for 100 min induced testicular atrophy in which some of seminiferous tubules showed complete depletion of spermatogenic germ cells. Lens epithelial cells and lens fiber were swollen and showed granular changes in an exposure time dependent manner. However, boron carrier treatment had no significant effect on the lesions. These results suggest that the examination of histopathological changes of lens and testis can be used as "biological dosimeters" for gauging radiation responses and the HANARO Nuclear Reactor has sufficient capacities for the BNCT.