Photoluminescence of MoS2 on Plasmonic Gold Nanoparticles Depending on the Aggregate Size.

Transition metal dichalcogenides (TMDs) are promising candidates for ultrathin functional semiconductor devices. In particular, incorporating plasmonic nanoparticles into TMD-based devices enhances the light-matter interaction for increased absorption efficiency and enables control of device performance such as electronic, electrical, and optical properties. In this heterohybrid structure, manipulating the number of TMD layers and the aggregate size of plasmonic nanoparticles is a straightforward approach to tailoring device performance. In this study, we use photoluminescence (PL) spectroscopy, which is a commonly employed technique for monitoring device performance, to analyze the changes in electronic and optical properties depending on the number of MoS2 layers and the size of the gold nanoparticle (AuNP) aggregate under nonresonant and resonant excitation conditions. The PL intensity in monolayer MoS2/AuNPs increases as the size of aggregates increases irrespective of the excitation conditions. The strain induced by AuNPs causes a red shift, but as the aggregates grow larger, the effect of p-doping increases and the blue shift becomes prominent. In multilayer MoS2/AuNPs, quenched PL intensity is observed under nonresonant excitation, while enhancement is noted under resonant excitation, which is mainly contributed by p-doping and LSPR, respectively. Remarkably, the alteration in the spectral shape due to resonant excitation is evident solely in small aggregates of AuNPs across all layers.

Treatment of conus medullaris arteriovenous malformation: the role of microsurgical treatment.

OBJECTIVE: Conus medullaris arteriovenous malformation (AVM) is rare and challenging to treat. To better define the presentation, prognosis, and optimal treatment of these lesions, the authors present their treatment experiences for conus medullaris AVM. METHODS: Eleven patients with AVM of the conus medullaris were identified between March 2013 and December 2021. Among these patients, 7 who underwent microsurgical treatment were included. Patient data, including age, sex, symptoms at presentation, neurological status, radiological findings, nidus depth (mainly pial lesion vs intramedullary lesion), type of treatment, and recurrence at follow-up, were collected. Postoperative angiography was performed in all patients. Spinal cord function was evaluated using the Frankel grade at the time of admission and 1 year after surgery. RESULTS: All 7 patients presenting with myeloradiculopathy were treated surgically. Four patients (57.1%) underwent endovascular embolization, followed by resection. The other 3 patients underwent microsurgery only. Complete occlusion was confirmed with postoperative angiography in all patients. Of the 3 patients who were nonambulatory before surgery (Frankel grade C), 2 were able to walk after surgery (Frankel grade D) and 1 remained nonambulatory (Frankel grade C) at 1-year follow-up. CONCLUSIONS: Based on the authors' clinical experiences, the results of multimodal treatment for conus medullaris AVM are good, with microsurgical treatment playing an important role. The microsurgical strategy can differ depending on the location of the nidus, and when possible, good results can be expected through microsurgical resection.

Risk of Cerebral Aneurysm Rupture After Liver Transplantation: Development and Validation of a Hemorrhagic Stroke Scoring Model.

BACKGROUND: Liver transplantation (LT) patients appear to be more prone to neurological events compared to individuals undergoing other types of solid-organ transplantation. The aims of the present study were to analyze the prevalence of unruptured intracranial aneurysms (UIAs) in patients undergoing liver transplantation (LT) and to examine the perioperative occurrence of subarachnoid hemorrhage (SAH). Also, it intended to systematically identify the risk factors of SAH and hemorrhagic stroke (HS) within a year after LT and to develop a scoring system which involves distinct clinical features of LT patients. METHODS: Patients who underwent LT from January 2012 to March 2022 were analyzed. All included patients underwent neurovascular imaging within 6 months before LT. We conducted an analysis of prevalence and radiological features of UIA and SAH. The clinical factors that may have an impact on HS within one year of LT were also reviewed. RESULTS: Total of 3,487 patients were enrolled in our study after applying inclusion and exclusion criteria. The prevalence of UIA was 5.4%. The incidence of SAH and HS within one year following LT was 0.5% and 1.6%, respectively. We developed a scoring system based on multivariable analysis to predict the HS within 1-year after LT. The variables were a poor admission mental status, the diagnosis of UIA, serum ammonia levels, and Model for End-stage Liver Disease (MELD) scores. Our model showed good discrimination among the development (C index, 0.727; 95% confidence interval [CI], 0.635-0.820) and validation (C index, 0.719; 95% CI, 0.598-0.801) cohorts. CONCLUSION: The incidence of UIA and SAH was very low in LT patients. A poor admission mental status, diagnosis of UIA, serum ammonia levels, and MELD scores were significantly associated with the risk of HS within one year after LT. Our scoring system showed a good discrimination to predict the HS in LT patients.

The efficacy of surgical site suction drain insertion in pterional craniotomy for intracranial cerebral aneurysm.

Objective: We evaluated the role of subgaleal closed suction drains in postoperative epidural hematoma (EDH) and wound complications following pterional craniotomy for cerebral aneurysm. Methods: We reviewed 5,280 pterional craniotomies performed on 5,139 patients between January 2006 and December 2020. A drain was placed subgalealy and tip of drain was positioned between the bone flap and the deep temporalis. 1,637 cases (31%) had a subgaleal suction drain. We analyzed demographic and clinical variables related to EDH requiring evacuation and wound complications in patients with and without drains. Univariate and multivariate logistic regression analyses were performed to determine the associated risk factors. Results: Fourteen cases (0.27%) of EDH requiring evacuation and 30 cases (0.57%) of wound complications were identified. Univariate analysis found that drain insertion, subarachnoid hemorrhage (SAH), and operation time were associated with EDH, while drain insertion, SAH, male gender, older age, and longer operation time were associated with wound complications. Multivariate analysis found no significant association between drain use and EDH (OR=1.62, p=0.402) or wound complications (OR=1.45, p=0.342). Conclusions: Routine use of subgaleal closed suction drains may not be necessary after pterional craniotomy, as drain insertion was not associated with a reduced risk of EDH requiring evacuation or wound complications.

Rapid quantitative PCR equipment using photothermal conversion of Au nanoshell.

The emergence of infectious diseases worldwide necessitates rapid and precise diagnostics. Using gold nanoshells in the PCR mix, we harnessed their unique photothermal properties in the near-infrared regime to attain efficient heating, reaching ideal photothermal PCR cycle temperature profile. Our photothermal PCR method expedited DNA amplification while retaining its detection sensitivity. Combining photothermal quantitative PCR with real-time fluorometry and non-invasive temperature measurement, we could amplify the target DNA within just 25 min, with a minimum detectable DNA amount of 50 picograms. This innovation in photothermal qPCR, leveraging the photothermal properties of gold nanoshells, will pave the way for immediate point-of-care diagnostics of nucleic acid biomarkers.

Chemical and perfusion markers as predictors of moyamoya disease progression and complication types.

To investigate the association between chemical markers (triglyceride, C-reactive protein (CRP), and inflammation markers) and perfusion markers (relative cerebral vascular reserve (rCVR)) with moyamoya disease progression and complication types. A total of 314 patients diagnosed with moyamoya disease were included. Triglyceride and CRP levels were assessed and categorized based on Korean guidelines for dyslipidemia and CDC/AHA guidelines, respectively. Perfusion markers were evaluated using Diamox SPECT. Cox proportional hazard analysis was performed to examine the relationship between these markers and disease progression, as well as complication types (ischemic stroke, hemorrhagic stroke, and rCVR deterioration). Elevated triglyceride levels (≥ 200) were significantly associated with higher likelihood of end-point events (HR: 2.292, CI 1.00-4.979, P = 0.03). Severe decreased rCVR findings on Diamox SPECT were also significantly associated with end-point events (HR: 3.431, CI 1.254-9.389, P = 0.02). Increased CRP levels and white blood cell (WBC) count were significantly associated with moyamoya disease progression. For hemorrhagic stroke, higher triglyceride levels were significantly associated with end-point events (HR: 5.180, CI 1.355-19.801, P = 0.02). For ischemic stroke, severe decreased rCVR findings on Diamox SPECT (HR: 5.939, CI 1.616-21.829, P < 0.01) and increased CRP levels (HR: 1.465, CI 1.009-2.127, P = 0.05) were significantly associated with end-point events. Elevated triglyceride, CRP, and inflammation markers, as well as decreased rCVR, are potential predictors of moyamoya disease progression and complication types. Further research is warranted to understand their role in disease pathophysiology and treatment strategies.

Superficial temporal artery interposition bypass for the treatment of complex intracranial aneurysms: Flexible and creative options for flow preservation bypass.

PURPOSE: Flow-preservation bypass is a treatment option for complex intracranial aneurysms (IAs) that cannot be managed with microsurgical clipping or endovascular treatment. Various bypass methods are available, including interposition grafts such as the radial artery or saphenous vein. Size discrepancy, invasiveness, and procedure complexity must be considered when using interposition grafts. We describe our experience of treating complex IAs using a superficial temporal artery (STA) interposition bypass. METHODS: We retrospectively reviewed the medical records and operative videos of all patients who were treated for complex IAs at our center from January 2009 to December 2021 using cerebral revascularization. Clinical, radiological, and surgical findings of the cases that underwent STA interposition bypass were investigated. RESULTS: Seventy-six bypass procedures were performed of which seven (9.2%) complex IAs were managed using STA interposition bypass. Of these 5 cases were of anterior cerebral artery, 1 of middle cerebral artery, and 1 of posterior inferior cerebellar artery aneurysm. There were no postoperative ischemic complications. Revision surgery for postoperative pseudomeningocele was performed in one case. The long-term bypass patency rate was 85.7% (6 out of 7) and good long-term aneurysm control was achieved in all cases, with a mean follow-up of 64 months. CONCLUSIONS: When treating complex IAs, creative revascularization strategies are needed in selective cases for favorable outcomes. STA interposition graft bypass which can reduce the size discrepancy between the donor and recipient may be a less invasive, flexible, and practical option for treating complex IAs.

Ruptured Medullary Hemangioblastoma Mimicking a Craniocervical Junction Dural Arteriovenous Fistula with a Pseudoaneurysm.

Hemangioblastomas (HBMs) are rare vascular tumors commonly located in the posterior fossa of adults. A mid-50s patient presented with sudden unconsciousness. Computed tomography scans revealed acute hemorrhages around the posterior fossa, predominantly in the subarachnoid space. Digital subtraction angiography (DSA) revealed an 8-mm round lesion filled with contrast agent, fed by the C1 segmental artery of the left vertebral artery (VA), showing early venous drainage to the spinal cord and brainstem. Emergent embolization was attempted under suspicion of a ruptured dural arteriovenous fistula, resulting in parent artery occlusion due to feeder selection failure. Follow-up DSA after a month depicted a persistent aneurysm via collaterals from both VAs. Consequently, the decision was made to proceed with surgical intervention, leading to the resection of the lesion, confirming its diagnosis as a HBM through histological examination. This case underscores the potential for misdiagnosis when HBMs with an intratumoral shunt mimic vascular shunt lesions.

Mass Effect After Flow Diversion for Unruptured Large and Giant Cavernous or Paraclinoid Internal Carotid Artery Aneurysm.

OBJECTIVE: The mass effect associated with large or giant intracranial aneurysms is difficult for traditional endovascular treatment. This study investigated whether flow diverters can relieve the aneurysmal mass effect caused by aneurysmal compression symptoms. METHODS: Fifty-five patients with unruptured large and giant intracranial aneurysms treated by a flow diverter at our institution from January 2014 to February 2022 were retrospectively evaluated. RESULTS: In this study, 53 patients were included. Initially, 27 patients (51.9%), including 10 with compressive optic neuropathy, 12 with third nerve palsy, 2 with facial hyperesthesia, and 11 with sixth nerve palsy, were symptomatic. The symptom duration was shorter in the improved group (n = 2.2 ± 4.0 vs. n = 3.1 ± 3.9, P = 0.49). Thrombus formation following the flow diversion procedure was typically observed on magnetic resonance imaging (MRI) performed immediately and was not significantly associated with symptomatic improvement (OR = 0.395; 95% CI (0.058-2.698), P = 0.343). However, symptomatic improvement was seen in most patients when the aneurysm size decreased on MRI. A reduction in the aneurysm size on the MRI at the 3-month follow-up was correlated with symptomatic improvement in the multivariate analysis (OR = 0.08, 95% CI (0.013-0.485), P < 0.05). CONCLUSIONS: A flow diverter might help alleviate compression symptoms caused by large or giant intracranial aneurysms. Shrinkage of the aneurysm within 3 months postoperatively and a shorter duration of symptoms contribute to the favorable outcomes of mass effect. Ultimately, prompt treatment is crucial for improving symptomatic intracranial artery aneurysms.

Anti-Cancer Effect of Neural Stem Cells Transfected with Carboxylesterase and sTRAIL Genes in Animals with Brain Lesions of Lung Cancer.

A metastatic brain tumor is the most common type of malignancy in the central nervous system, which is one of the leading causes of death in patients with lung cancer. The purpose of this study is to evaluate the efficacy of a novel treatment for metastatic brain tumors with lung cancer using neural stem cells (NSCs), which encode rabbit carboxylesterase (rCE) and the secretion form of tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL). rCE and/or sTRAIL were transduced in immortalized human fetal NSCs, HB1.F3. The cytotoxic effects of the therapeutic cells on human lung cancer cells were evaluated in vitro with the ligands and decoy receptor expression for sTRAIL in the presence of CPT-11. Human NSCs encoding rCE (F3.CE and F3.CE.sTRAIL) significantly inhibited the growth of lung cancer cells in the presence of CPT-11 in vitro. Lung cancer cells were inoculated in immune-deficient mice, and therapeutic cells were transplanted systematically through intracardiac arterial injection and then treated with CPT-11. In resting state, DR4 expression in lung cancer cells and DcR1 in NSCs increased to 70% and 90% after CPT-11 addition, respectively. The volumes of the tumors in immune-deficient mice were reduced significantly in mice with F3.CE.sTRAIL transplantation and CPT-11 treatment. The survival was also significantly prolonged with treatment with F3.sTRAIL and F3.CE plus CPT-11 as well as F3.CE.sTRAIL plus CPT-11. NSCs transduced with rCE and sTRAIL genes showed a significant anti-cancer effect on brain metastatic lung cancer in vivo and in vitro, and the effect may be synergistic when rCE/CPT-11 and sTRAIL are combined. This stem-cell-based study using two therapeutic genes of different biological effects can be translatable to clinical application.

Treatment of Dural Arteriovenous Fistula with Intradural Draining Vein at the Craniocervical Junction: Case Series with Special Reference to the Anatomical Considerations.

BACKGROUND: Dural arteriovenous fistulas at the craniocervical junction (CCJ DAVFs) are a rare vascular disease. Endovascular treatment (EVT) and microsurgery are the primary treatment modalities for CCJ DAVFs. However, incomplete treatment or complications may occur after treatment because of the anatomical complexity. OBJECTIVE: We analyzed the neurosurgical treatment experiences of CCJ DAVFs to recommend suitable classification and treatment options. METHODS: CCJ DAVFs were anatomically classified into three types according to the feeding arteries and their relationships with the anterior spinal (ASAs) and lateral spinal arteries (LSAs). Type 1 was fed by the radiculomeningeal artery from the vertebral artery and was not associated with the ASA or LSA. Type 2 was fed by the radiculomeningeal artery, and the radicular artery supplied the LSA near the fistula point. Type 3 had the characteristics of type 1 or type 2 CCJ DAVFs, except the ASA also contributed to the fistula. RESULTS: There were 5, 7, and 4 cases of type 1, type 2, and type 3 CCJ DAVFs, respectively. EVT was attempted in 12 patients, of whom only 1 (type 1) was completely cured without complications. Nine cases had residual lesions after EVT, and two had spinal cord infarction due to occlusion of the LSA. Fourteen patients underwent microsurgical treatment. In all 14 cases, CCJ DAVFs were completely obliterated after microsurgery. CONCLUSION: In cases of type 1 CCJ DAVF, both microsurgical treatment and EVT may be considered. However, for type 2 and 3 CCJ DAVFs, microsurgery may be a superior treatment modality.

Aquaporin-4 Deficiency is Associated with Cognitive Impairment and Alterations in astrocyte-neuron Lactate Shuttle.

Cognitive impairment refers to notable declines in cognitive abilities including memory, language, and emotional stability leading to the inability to accomplish essential activities of daily living. Astrocytes play an important role in cognitive function, and homeostasis of the astrocyte-neuron lactate shuttle (ANLS) system is essential for maintaining cognitive functions. Aquaporin-4 (AQP-4) is a water channel expressed in astrocytes and has been shown to be associated with various brain disorders, but the direct relationship between learning, memory, and AQP-4 is unclear. We examined the relationship between AQP-4 and cognitive functions related to learning and memory. Mice with genetic deletion of AQP-4 showed significant behavioral and emotional changes including hyperactivity and instability, and impaired cognitive functions such as spatial learning and memory retention. 18 F-FDG PET imaging showed significant metabolic changes in the brains of AQP-4 knockout mice such as reductions in glucose absorption. Such metabolic changes in the brain seemed to be the direct results of changes in the expression of metabolite transporters, as the mRNA levels of multiple glucose and lactate transporters in astrocytes and neurons were significantly decreased in the cortex and hippocampus of AQP-4 knockout mice. Indeed, AQP-4 knockout mice showed significantly higher accumulation of both glucose and lactate in their brains compared with wild-type mice. Our results show that the deficiency of AQP-4 can cause problems in the metabolic function of astrocytes and lead to cognitive impairment, and that the deficiency of AQP4 in astrocyte endfeet can cause abnormalities in the ANLS system.

Clipping of Unruptured Anterior Choroidal Artery Aneurysms Together with Small Branches: Safety Confirmation Using Intraoperative Indocyanine Green Video-Angiography and Intraoperative Neurophysiological Monitoring.

BACKGROUND: In treating anterior choroidal artery (AChA) aneurysms, preserving the AChA main trunk is of course necessary to prevent postoperative ischemic complications. However, in practice, complete occlusions are often limited by small branches. OBJECTIVE: We aimed to demonstrate that even in cases where complete occlusion of the AChA aneurysm is complex due to small branches, complete occlusion can be safely achieved using indocyanine green video-angiography and intraoperative neurophysiological monitoring (IONM). METHODS: We performed a retrospective review of all unruptured AChA aneurysms surgically treated at our institution from 2012 to 2021. All available surgical videos were reviewed to find AChA aneurysms clipped with small branches; clinical and radiological data were collected for these cases. RESULTS: Among 391 cases of unruptured AChA aneurysms treated surgically, 25 AChA aneurysms were clipped with small branches. AChA-related ischemic complications occurred in 2 cases (8%) without retrograde indocyanine green filling to the branches. These 2 cases had changes in IONM. There were no ischemic complications in the remaining cases with retrograde indocyanine green filling to the branches and no change in IONM. During an average follow-up of 47 months (12-111 months), a small residual neck was observed in 3 cases (12%) and recurrence or progression of the aneurysm was observed in only 1 case (4%). CONCLUSIONS: The surgical treatment of AChA aneurysms carries the risk of devastating ischemic complications. Even in cases where complete clip ligation seems impossible due to small branches associated with AChA aneurysms, complete occlusion can be safely achieved using indocyanine green video-angiography and IONM.

Efficacy of Acetylcysteine and Selenium in Aneurysmal Subarachnoid Hemorrhage Patients: A Prospective, Multicenter, Single Blind Randomized Controlled Trial.

BACKGROUND: Subarachnoid hemorrhage (SAH) patients have oxidative stress results in inflammation, tissue degeneration and neuronal damage. These deleterious effects cause aggravation of the perihematomal edema (PHE), vasospasm, and even hydrocephalus. We hypothesized that antioxidants may have a neuroprotective role in acute aneurysmal SAH (aSAH) patients. METHODS: We conducted a prospective, multicenter randomized (single blind) trial between January 2017 and October 2019, investigating whether antioxidants (acetylcysteine and selenium) have the potential to improve the neurologic outcome in aSAH patients. The antioxidant patient group received antioxidants of acetylcysteine (2,000 mg/day) and selenium (1,600 µg/day) intravenously (IV) for 14 days. These drugs were administrated within 24 hours of admission. The non-antioxidant patient group received a placebo IV. RESULTS: In total, 293 patients were enrolled with 103 patients remaining after applying the inclusion and exclusion criteria. No significant differences were observed in the baseline characteristics between the antioxidant (n = 53) and non-antioxidant (n = 50) groups. Among clinical factors, the duration of intensive care unit (ICU) stay was significantly shortened in patients who received antioxidants (11.2, 95% confidence interval [CI], 9.7-14.5 vs. 8.3, 95% CI, 6.2-10.2 days, P = 0.008). However, no beneficial effects were observed on radiological outcomes. CONCLUSION: In conclusion, antioxidant treatment failed to show the reduction of PHE volume, mid-line shifting, vasospasm and hydrocephalus in acute SAH patients. A significant reduction in ICU stay was observed but need more optimal dosing schedule and precise outcome targets are required to clarify the clinical impacts of antioxidants in these patients. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004628.

Is Fetal-Type Posterior Cerebral Artery a Risk Factor for Recurrence in Coiled Internal Carotid Artery-Incorporating Posterior Communicating Artery Aneurysms? Analysis of Conventional Statistics, Computational Fluid Dynamics, and Random Forest With Hyper-Ensemble Approach.

BACKGROUND: The fetal-type posterior cerebral artery (FPCA) has been regarded as the risk factor for recurrence in coiled internal carotid artery-incorporating posterior communicating artery (ICA-PCoA) aneurysm. However, it has not been proven in previous literature studies. OBJECTIVE: To reveal the impact of FPCA on the recurrence of ICA-PCoA aneurysms using conventional statistical analysis, computational fluid dynamics (CFD) simulation, and random forest with hyper-ensemble approach (RF with HEA). METHODS: Vascular parameters and clinical information from patients who underwent coil embolization ICA-PCoA aneurysms from January 2011 to December 2016 were obtained. Conventional statistical analysis was applied to a total of 95 cases obtained from patients with a follow-up of more than 6 months. For CFD simulation, 3 sets of three-dimensional models were used to understand the hemodynamical characteristics of various FPCAs. The RF with HEA was applied to reinforce the clinical data analysis. RESULTS: The conventional statistical analysis fails to reveal that FPCA is a risk factor. CFD analysis shows that the diameter of FPCA alone is less likely to be a risk factor. The RF with HEA shows that the impact of FPCA is also minor compared with that of the packing density in the recurrence of coiled ICA-PCoA aneurysms. CONCLUSION: The gathered results of all 3 analyses show more clear evidence that FPCA is not a risk factor for coiled ICA-PCoA aneurysms. Hence, we may conclude that FPCA itself is doubtful to be the major risk factor in the recurrence of coiled ICA-PCoA aneurysms.

Necessity of mandatory postoperative intensive care unit management after clipping surgery for unruptured intracranial aneurysms.

OBJECTIVE: Many neurosurgeons routinely perform postoperative intensive care unit (ICU) management after clipping of unruptured intracranial aneurysms (UIAs). However, whether routine postoperative ICU care is necessary remains a clinical question. Therefore, we investigated which factors acted as risk factors that actually required ICU care after microsurgical clipping of unruptured aneurysms. METHODS: We included a total of 532 patients who underwent clipping surgery for UIA between January 2020 and December 2020. The patients were divided into two groups: those who really required ICU care (41 patients, 7.7%) and those who did not (491 patients, 92.3%). A backward stepwise logistic regression model was used to identify factors that were independently associated with ICU care requirement. RESULTS: The mean hospital stay duration and the operation time were significantly longer in the ICU requirement group than in the no ICU requirement group (9.9 ± 10.7 vs. 6.3 ± 3.7 days, p = 0.041), (259.9 ± 128.4 vs. 210.5 ± 46.1 min, p = 0.019). The transfusion rate was significantly higher (p = 0.024) in the ICU requirement group. Multivariable logistic regression analysis identified male sex (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.15-4.76; p = 0.0195), operation time (OR, 1.01; 95% CI, 1.00-1.01; p = 0.0022), and transfusion (OR, 2.35; 95% CI, 1.00-5.51; p = 0.0500) as independent risk factors for requiring ICU care after clipping. CONCLUSIONS: Postoperative ICU management may not be mandatory after clipping surgery for UIAs. Our results suggest that postoperative ICU management may be more required in the male sex, patients with longer operation times, and those who received a transfusion.

The risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms: anatomical consideration and infarction territory.

PURPOSE: An anterior communicating artery is a common location for both ruptured and unruptured intracranial aneurysms, and microsurgery is sometimes necessary for their successful treatment. However, postoperative infarction should be considered during clipping due to the complex surrounding structures of anterior communicating artery aneurysms. This study aimed to evaluate the risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms and its clinical outcomes. METHODS: The data of patients who underwent microsurgical clipping of an unruptured anterior communicating artery aneurysm in our hospital between January 2008 and December 2020 were retrospectively analyzed. The patients' demographic data, anatomical features of the anterior communicating artery complex and aneurysm, surgical technique, characteristics of postoperative infarction, and its clinical course were evaluated. RESULTS: Notably, among 848 patients, 66 (7.8%) and 34 (4%) patients had radiologic and symptomatic infarctions, respectively. Univariate and multivariate logistic regression analyses showed that hypertension (odds ratio (OR), 1.99; [Formula: see text]), previous stroke (OR, 3.89; [Formula: see text]), posterior projection (OR, 5.58; [Formula: see text]), aneurysm size (OR, 1.17; optimal cut-off value, 6.14 mm; [Formula: see text]), and skull base-to-aneurysm distance (OR, 1.15; optimal cut-off value, 11.09 mm; [Formula: see text]) were associated with postoperative infarction. In the pterional approach, a closed A2 plane was an additional risk factor (OR, 1.88; [Formula: see text]). Infarction of the subcallosal and hypothalamic branches was significantly associated with symptomatic infarction ([Formula: see text]). CONCLUSION: Hypertension, previous stroke, posteriorly projecting aneurysms, aneurysm size, and highly positioned aneurysms are independent risk factors for postoperative infarction during surgical clipping of an unruptured anterior communicating artery aneurysm. Additionally, a closed A2 plane is an additional risk factor of postoperative infarction in patients undergoing clipping via the pterional approach.

Efficacy of intraoperative neuromonitoring (IONM) and intraoperative indocyanine green videoangiography (ICG-VA) during unruptured anterior choroidal artery aneurysm clipping surgery.

OBJECTIVE: The aim of this study was to investigate the efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and intraoperative neuromonitoring (IONM) to prevent postoperative ischemic complications during microsurgical clipping of unruptured anterior choroidal artery (AChA) aneurysms. METHODS: We retrospectively reviewed the clinical and radiological records of all patients who had undergone microsurgical clipping for unruptured AChA aneurysms at our institution between April 2001 and December 2019. We compared the postoperative complication rate of the group for which intraoperative ICG-VA and IONM were utilized (group B; n=324) with that of the group for which intraoperative ICG-VA and IONM were not utilized (group A; n=72). RESULTS: There were no statistically significant differences in demographic data between the two groups. Statistically significant differences were observed in the rate of overall complications (p=0.014) and postoperative ischemic complications related to AChA territory (p=0.039). All the cases (n=4) in group B who had postoperative infarctions related to AChA territory showed false-negative results of intraoperative ICG-VA and IONM. CONCLUSIONS: Preserving the patency of the AChA is essential to minimize postoperative complications. Intraoperative monitoring tools including ICG-VA and IONM can greatly contribute to lowering complication rates. However, their pitfalls and false-negative results should always be considered.

Cerebral Myxomatous Aneurysms: Case Series and Systematic Review of Literature with Adequate Follow-Up Periods and Aneurysmal Wall Biopsy Results.

BACKGROUND: Cerebral myxomatous aneurysms (CMA) are intracranial aneurysms caused by cardiac myxoma. The exact mechanism underlying their development has not yet been elucidated. And an optimal treatment method has not yet been established because of rarity of the disease. In addition, most existing reports have had a short follow-up period or lack of follow-up imaging test results. The aim of this study was to provide better insights into the course and treatment options of CMAs. METHODS: We describe 4 CMA patients treated in our hospital and literature search was performed using PubMed and Embase databases. Keywords used were as follows: "cerebral myxomatous aneurysm", "myxomatous aneurysm", "cardiac myxoma", and "intracranial aneurysm". Only publications in English and related to this disorder with adequate follow-up periods and aneurysmal wall biopsy results were included. Clinical, radiological, pathological, and treatment characteristics were analyzed. RESULTS: A total of 149 CMA cases were managed conservatively that included 9 enlargements, 6 regressions, and 134 stable aneurysms, which were identified for a total of 453.33 aneurysm years (1.91% per aneurysm year, 1.27% per aneurysm year, and 28.76% per aneurysm year, respectively). Poor outcome rate was high in cases with hemorrhage (either parenchymal or subarachnoidal hemorrhage) due to rupture of the CMA (46.67%, 7 out of 15). Thirteen cases had aneurysm biopsy results of which 11 showed tumor invasion on the aneurysm wall. CONCLUSIONS: Even though the natural course of unruptured, benign-looking CMAs appears to be favorable, the presence or absence of viable tumor cells in the aneurysm may promote an unfavorable disease course. In the case of large, symptomatic, and enlarging CMAs, surgical, endovascular, or combined treatment should be considered as the mortality and morbidity due to rupture might be high.

Pseudoaneurysm formation or dural arteriovenous fistula formation at the middle meningeal artery following revascularization surgery in Moyamoya disease.

Moyamoya disease (MMD) is a rare progressive steno-occlusive cerebrovascular disorder. Currently, revascularization surgery is used as optimal treatment to overcome MMD. However, revascularization for MMD has reported several complications. Also, iatrogenic complications such as pseudoaneurysms formation or dural arteriovenous fistulas (dAVFs) formation-has been identified in rare cases after the surgical intervention for revascularizations. We describe two cases. In first case, the patency of the anastomosis site was good and saccular type pseudoaneurysm formation was found at parietal branch of posterior middle meningeal artery (MMA) in transfemoral cerebral angiography (TFCA) performed on the twelfth day after surgery. We decided to treat pseudoaneurysm by endovascular embolization the next day, but the patient was shown unconsciousness and anisocoria during sleep at that day. Computed tomography showed massive subdural hemorrhage at the ipsilateral side, thus we performed decompressive craniectomy and hematoma evacuation. In second case, the patency of the anastomosis site was good and dAVF formation at right MMA was found in TFCA performed on the sixth day after surgery. We performed endovascular obliteration of the arteriovenous fistula under local anesthesia. Pseudoaneurysm formation or dAVF formation after revascularization surgery is an exceptional case. If patients have such complications, practioner should carefully screen the patients by implementing digital subtraction angiogram to identify anatomic features; as well as consider immediate treatment in any way, including embolization or other surgery.