Postoperative Airway Management after Anterior Cervical Spine Surgery: Retrospective Neurosurgical Multicenter Study.

Airway complications that occur after anterior cervical spine surgery pose a life-threatening risk, which encompasses complications including prolonged intubation, unplanned reintubation, and/or necessity of tracheostomy. The present study aimed to identify the surgical risks associated with postoperative airway complications in neurosurgical training institutes. A retrospective, multicenter, observational review of data from 365 patients, who underwent anterior cervical spine surgery between 2018 and 2022, at three such institutes was carried out. Postoperative airway complication was defined as either the need for prolonged intubation on the day of surgery or the need for unplanned reintubation. The perioperative medical information was obtained from their medical records. The average age of the cohort was over 60 years, with males comprising approximately 70%. Almost all surgeries predominantly involved anterior cervical discectomy and fusion or anterior cervical corpectomy and fusion, with most surgeries occurring at the level of C5/6. In total, 363 of 365 patients (99.5%) were extubated immediately after surgery, and the remaining two patients were kept under intubation because of the risk of airway complications. Of the 363 patients who underwent extubation immediately after surgery, two (0.55%) required reintubation because of postoperative airway complications. Patients who experienced airway complications were notably older and exhibited a significantly lower body mass index. The results of this study suggested that older and frailer individuals are at an elevated risk for postoperative airway complications, with immediate postoperative extubation generally being safe but requiring careful judgment in specific cases.

[Usefulness of Preoperative Simulation: Skull Base Approach].

Preoperative simulation images creates an accurate visualization of a surgical field. The anatomical relationship of the cranial nerves, arteries, brainstem, and related bony protrusions is important in skull base surgery. However, an operator's intention is unclear for a less experienced neurosurgeon. Three-dimensional(3D)fusion images of computed tomography and magnetic resonance imaging created using a workstation aids precise surgical planning and safety management. Since the simulation images allows to perform virtual surgery, a déjà vu effect for the surgeon can be obtained. Additionally, since 3D surgical images can be used for preoperative consideration and postoperative verification, discussion among the team members is effective from the perspective of surgical education for residents and medical students. Significance of preoperative simulation images will increase eventually.

Comparison of outcomes with/without preoperative embolization for meningiomas with diluted N-butyl-2-cyanoacrylate.

BACKGROUND: Preoperative embolization for meningiomas is controversial regarding its effectiveness in reducing intraoperative blood loss and operative time. In contrast, some reports have documented improved surgical outcomes in large meningiomas. In this study, we retrospectively compared the outcomes of craniotomy for meningiomas with/without preoperative embolization with diluted N-butyl-2-cyanoacrylate (NBCA) primarily in a single institution. METHODS: Data (World Health Organization grade, Simpson grade, maximum tumor diameter, intraoperative bleeding, operative time, history of hypertension, and time from embolization to craniotomy) of patients with initial intracranial meningiomas were compared with or without preoperative embolization from January 2015 to April 2022. RESULTS: The embolization group consisted of 56 patients and the nonembolization group included 76 patients. Diluted NBCA (13% concentration for all patients) was used in 51 of 56 patients (91.1%) who underwent transarterial embolization. Permanent neurological complications occurred in 2 (3.6%) patients. Intraoperative bleeding was significantly lower in the embolization group for a maximum tumor diameter ≥40 mm (155 vs. 305 ml, respectively, p < 0.01). In the nonembolization group, for a maximum tumor diameter ≥30 mm, patients with hypertension had more intraoperative bleeding than non-hypertensive ones. CONCLUSIONS: Despite its limitations, the present results showed that, under certain conditions, preoperative embolization for intracranial meningiomas caused less intraoperative bleeding. The safety of treatment was comparable with that reported in the Japan Registry of NeuroEndovascular Therapy 3 (JR-NET3) with a complication rate of 3.7% for preoperative embolization of meningiomas, despite the treatment focused on the liquid embolization material.

Mechanical Thrombectomy for Acute Cardiogenic Internal Carotid Artery Occlusion with Cross-Flow through the Communicating Artery.

AIM: To report mechanical thrombectomy (MT) for internal carotid artery (ICA) occlusion with cross-flow through the communicating artery ("with" group), and to compare it with ICA or middle cerebral artery occlusion without cross-flow ("without" group). MATERIAL AND METHODS: This study included 10 and 57 cases of the "with" and "without" groups, respectively. Cases analyzed by rapid processing of perfusion and diffusion (RAPID) since October 2020 were included. RESULTS: Puncture-to-reperfusion time was 78.5 and 39 min (p=0.0155), the National Institutes of Health Stroke Scale score at discharge was 10.5 and 4 (p=0.0166), decline from pre to post Diffusion-Weighted Image-Alberta Stroke Program Early computed tomography (CT) Score was 0.5 and 0 (p=0.0495), and the modified Rankin Scale score at 90 days was 4 and 2 (p=0.0195) in the "with" and "without" groups, respectively. Furthermore, Tmax values of > 6 s (50 cc vs. 164 cc; p=0.0277) and Tmax > 4 s/Tmax > 6 s ratio (3.23 vs. 1.55) (p=0.0074) were significantly different between the "with" and "without" groups. CONCLUSION: The "with" group may have been affected by the longer treatment time and being at high risk of distal migration of thrombus due to poor prognosis. Although the region with a Tmax of > 6 s tends to be small in patients of the "with" group, it indicates a low-perfusion state that can lead to cerebral infarction, and MT should be performed.

Surgical Outcomes and Medical Costs Associated with Spinal Cord Tumors: Comparison of Extramedullary and Intramedullary Tumors.

OBJECTIVE: This study aimed to clarify the differences in the perioperative data of patients with extramedullary and intramedullary tumors and estimate the impact of surgery on medical costs. METHODS: This single-center retrospective study included consecutive patients who underwent spinal tumor resection between September 2020 and December 2022. The perioperative medical information and medical costs for individual patients were obtained from their medical records. RESULTS: Thirty-two patients with extramedullary spinal cord tumors and 18 with intramedullary spinal cord tumors were included in the study. The 2 groups had no difference in surgery-related or major systemic complications. However, the operation time and the length of hospital stay were significantly longer and activities of daily living at discharge tended to worsen in the intramedullary tumor group compared to those in the extramedullary tumor group. As a result, the discharge outcome was significantly different between the 2 groups. The total medical costs for intramedullary tumors were approximately 1.43 times higher than those for extramedullary tumors. Further, a better functional outcome at discharge can save medical costs, regardless of extramedullary or intramedullary tumors. CONCLUSIONS: Surgery for intramedullary tumors can be performed with similar perioperative risks as for extramedullary tumors. However, intramedullary tumors are associated with concerns, such as prolonged hospitalization and worsening of activities of daily living at discharge, which ultimately result in higher medical costs.

Expression and distribution of hypoxia-inducible factor-1α and vascular endothelial growth factor in comparison between radiation necrosis and tumor tissue in metastatic brain tumor: A case report.

We report the case of a 70-year-old woman with metastatic brain tumors who underwent surgical removal of the tumor and radiation necrosis. The patient had a history of colon cancer and had undergone surgical removal of a left occipital tumor. Histopathological evaluation revealed a metastatic brain tumor. The tumor recurred six months after surgical removal, followed by whole-brain radiotherapy, and the patient underwent stereotactic radiosurgery. Six months later, the perifocal edema had increased, and the patient became symptomatic. The diagnosis was radiation necrosis and corticosteroids were initially effective. However, radiation necrosis became uncontrollable, and the patient underwent removal of necrotic tissue two years after stereotactic radiosurgery. Pathological findings predominantly showed necrotic tissue with some tumor cells. Since the vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were expressed around the necrotic tissue, the main cause of the edema was determined as radiation necrosis. Differences in the expression levels and distribution of HIF-1α and VEGF were observed between treatment-naïve and recurrent tumor tissue and radiation necrosis. This difference suggests the possibility of different mechanisms for edema formation due to the tumor itself and radiation necrosis. Although distinguishing radiation necrosis from recurrent tumors using MRI remains challenging, the pathophysiological mechanism of perifocal edema might be crucial for differentiating radiation necrosis from recurrent tumors.

Actin Alpha 2, Smooth Muscle (ACTA2) Is Involved in the Migratory Potential of Malignant Gliomas, and Its Increased Expression at Recurrence Is a Significant Adverse Prognostic Factor.

Malignant glioma is a highly invasive tumor, and elucidating the glioma invasion mechanism is essential for developing novel therapies. We aimed to highlight actin alpha 2, smooth muscle (ACTA2) as potential biomarkers of brain invasion and distant recurrence in malignant gliomas. Using the human malignant glioma cell line, U251MG, we generated ACTA2 knockdown (KD) cells treated with small interfering RNA, and the cell motility and proliferation of the ACTA2 KD group were analyzed. Furthermore, tumor samples from 12 glioma patients who underwent reoperation at the time of tumor recurrence were utilized to measure ACTA2 expression in the tumors before and after recurrence. Thereafter, we examined how ACTA2 expression correlates with the time to tumor recurrence and the mode of recurrence. The results showed that the ACTA2 KD group demonstrated a decline in the mean motion distance and proliferative capacity compared to the control group. In the clinical glioma samples, ACTA2 expression was remarkably increased in recurrent samples compared to the primary samples from the same patients, and the higher the change in ACTCA2 expression from the start to relapse, the shorter the progression-free survival. In conclusion, ACTA2 may be involved in distant recurrence in clinical gliomas.

Treatment Outcomes of 94 Cases of Pipeline Embolization Device in a Single Center: Predictive Factors of Incomplete Aneurysm Occlusion.

Objective: This study aimed to report the outcome of an endovascular treatment with a pipeline embolization device (PED) at a single center. We also examined the predictive factors for an incomplete occlusion after the PED placement. Methods: The subjects were 94 patients with 109 aneurysms who underwent the PED placement at our single center from June 2015 to September 2022. As treatment outcomes, we investigated the PED placement success rate, perioperative morbidity and mortality, postoperative cranial nerve improvement rate, and the classification of angiographic result at 6 months after the PED placement. Furthermore, the predictors of an incomplete occlusion were investigated in detail. Results: One hundred nine aneurysms locations were: C1 (9), C2 (30), C3 (15), C4 (53), and C5 (2) in the internal carotid artery segments. Perioperative morbidity, including the asymptomatic ones, occurred in 10 cases (10.6%). Among these 10 cases, the modified Rankin Scale (mRS) improved to preoperative mRS after 90 days in 9 cases except 1 case. On the other hand, no perioperative mortality was observed. The postoperative cranial nerve improvement rate was 84.4%, and 61.7% of patients had a complete occlusion in the follow-up angiography, 6 months after the PED placement. Predictive factors for an incomplete occlusion after the PED placement were the elderly aged 70 years or older (P-value = 0.0214), the elderly aged 75 years or older (P-value = 0.0009), and the use of anticoagulants (P-value = 0.0388) in an univariate analysis. Further, the multivariate analysis revealed that the elderly aged 75 years or older was a predictive factor of an incomplete occlusion in this study. Conclusion: We summarized the outcomes of the PED treatment at our single center. In this study, the elderly aged 75 years or older was a predictive factor of an incomplete occlusion after the PED placement.

Increasing C-reactive protein levels in a patient with glioblastoma with lymph node metastasis: a case report.

BACKGROUND: Glioblastoma usually recurs locally and extracranial metastases are rare. Most patients with extracranial metastases experience recurrence of the primary intracranial tumor. Lymph node metastases are often detected based on lymphadenopathy or symptoms caused by other metastatic sites. CASE PRESENTATION: Herein, we report a case of glioblastoma with lymph node metastasis in which the patient was asymptomatic but exhibited gradually increasing C-reactive protein levels prior to becoming febrile 9 months after the initial C-reactive protein increase. Diagnosis of lymph node metastasis that was delayed because the patient had a fever of unknown origin, no signs of infection, and the primary intracranial tumor did not recur. Chest computed tomography indicated supraclavicular, mediastinal, and hilar lymphadenopathy, and biopsy identified lymph node metastasis of glioblastoma. This is the fifth reported case of lymph node metastasis without intracranial recurrence. CONCLUSIONS: C-reactive protein levels may be a diagnostic marker for lymph node metastasis in patients with glioblastoma. Further evaluation is needed to elucidate the role of CRP in glioblastoma with lymph node metastasis.

Occult neurohypophyseal germinoma discovered during the course of long-term diabetes insipidus: illustrative case.

BACKGROUND: The authors report a case of occult neurohypophyseal germinoma detected in a patient with long-term diabetes insipidus. Central diabetes insipidus is the initial symptom in 95% of cases of neurohypophyseal germinoma. In occult neurohypophyseal germinomas, no abnormalities are seen on magnetic resonance imaging (MRI) at the onset of symptoms. It can take several months or even years for these changes to be detected on MRI. OBSERVATIONS: A 20-year-old male was diagnosed with central diabetes insipidus at the age of 17 years, and gonadal and adrenal corticosteroid insufficiency was noted at the age of 19 years. Head MRI showed an enlarged and enhanced pituitary stalk. He was referred to our department for a suspected neoplastic lesion. Endoscopic transsphenoidal biopsy indicated a pure germinoma. He was treated with chemotherapy and radiotherapy and then was discharged. LESSONS: In this case, new imaging findings appeared 19 months after the onset of diabetes insipidus, and the pathological diagnosis was made after almost 24 months. Because the patient had a history of growth hormone deficiency and had a positive test result for diabetes insipidus, occult neurohypophyseal germinoma was suspected, and periodic contrast-enhanced MRI monitoring was deemed essential.

Tmax volume can predict clinical type in patients with acute ischemic stroke.

OBJECTIVE: Endovascular therapy (EVT) is performed for acute ischemic stroke (AIS) with large vessel occlusion (LVO), however, the treatment strategies and clinical outcomes differ between cardiac embolism (CE) and intracranial arteriosclerosis-derived LVO (ICAS-LVO). We analyzed whether the time-to-max (Tmax) volume derived from perfusion imaging predicted clinical classification in AIS patients before EVT. METHODS: Consecutive AIS patients with anterior circulation LVO evaluated by automated imaging software were retrospectively identified. Patients were classified into a CE group and an ICAS-LVO group, and parameters were compared between groups. RESULTS: Thirty-nine patients were included and Tmax volume and Tmax > 6 s volume/Tmax > 4 s volume were significantly greater in the CE group than in the ICAS-LVO group (Tmax > 4 s volume: 261 mL vs. 149 mL, p = .01, Tmax > 6 s volume: 143 mL vs. 59 mL, p = .001, Tmax > 6 s volume/Tmax > 4 s volume: 0.59 vs. 0.40, p < .001). Multiple logistic regression analysis indicated an association between clinical classification and high Tmax > 6 s volume/Tmax > 4 s volume (p = .04). CONCLUSION: The Tmax volume derived from perfusion imaging predicts the clinical classification of AIS patients before EVT.

Using virtual lines of navigation for a successful transcortical approach.

Background: Neuronavigation systems have become essential tools in image-guided neurosurgery that aid in the accurate resection of brain tumors. Recent advancements to these devices can indicate the precise location of lesions but can also project an augmented reality (AR) image on the microscope eyepiece to facilitate a successful surgical operation. Although the transcortical approach is a very popular method in neurosurgery, it can lead to disorientation and can cause unnecessary brain damage when the distance from the brain surface to the lesion is long. Herein, we report on an actual case in which a virtual line from AR images was used to assist the transcortical approach. Methods: A virtual line connecting the entry point and the target point, which were set as the navigation route, was created using Stealth station S7® (Medtronic, Minneapolis, USA). This line was projected as an AR image on the microscope eyepiece. It was possible to reach the target point by proceeding through the white matter along the displayed virtual line. Results: The lesion was reached within a short duration using virtual line without disorientation. Conclusion: Setting a virtual line as an AR image using neuronavigation is a simple and accurate method that can effectively support the conventional transcortical approach.

Facial Spasm Caused by Compression of the Distal Portion of the Facial Nerve by the Anterior Inferior Cerebellar Artery, Resulting in Delayed Peripheral Facial Nerve Palsy: A Case Report.

Delayed onset of facial spasm following surgery for unilateral facial spasm after microvascular decompression (MVD) of the distal facial nerve is rare. We report a case of unilateral facial spasm caused by compression of the distal facial nerve successfully treated with MVD resulting in delayed peripheral facial nerve palsy. A 51-year-old male patient with a left facial spasm showed a gradual worsening of symptoms. Head imaging revealed that the left anterior inferior cerebellar artery (AICA) was in contact with the distal portion of the left facial nerve; hence, MVD was performed. The AICA was pressing on the distal facial nerve, so the AICA was transpositioned. Postoperatively, the facial spasm improved. On the eighth postoperative day, the patient showed left peripheral facial nerve palsy and was given conservative treatment. The patient was discharged home on the sixteenth postoperative day. One month after discharge, the facial palsy was in complete remission. Distal facial nerve compression may cause unilateral facial spasms. Although delayed facial nerve palsy may occur, the prognosis is good.

A Case of Fulminant Fat Embolism Syndrome With Very Early Onset After Femoral Neck and Sacral Fractures.

Fulminant fat embolism syndrome (FES) occurring within 1 h after trauma is extremely rare. We report a case of fulminant FES that developed hyperacute nature after a traumatic injury. A 66-year-old woman was injured when she fell approximately 1.5 m down the stairs. She was rushed to our hospital. One minute after arrival, which was 49 min after the injury, her consciousness and respiratory status deteriorated. Thoracoabdominal and pelvic computed tomography revealed preexisting interstitial pneumonia, a left femoral neck fracture, and a left sacral fracture. Head magnetic resonance imaging (diffusion-weighted imaging) showed diffuse high-signal areas and susceptibility-weighted imaging showed diffuse small perivascular of perivascular hemorrhages. She was diagnosed with fulminant FES. After conservative treatment, she was transferred to a rehabilitation hospital with a Glasgow Coma Scale (GCS) of 8 and a modified Rankin Scale of 5 on Day 45. The possibility of fulminant FES should be considered a cause of early impaired consciousness after a fracture.

Occult Germinoma of the Intramedullary Spinal Cord: A Case Report.

Primary germ cell tumors of the central nervous system (CNS) typically occur in the neurohypophysis, hypothalamus, or pineal gland and rarely in the spinal cord. We report a case of a spinal intramedullary tumor, which was first detected on magnetic resonance imaging (MRI) 41 months after the initial symptoms, with a verified pathological diagnosis of germinoma. The initial symptom was an abnormal sensation in the left plantar region that gradually worsened, resulting in severe sensory disturbance, difficulty in standing, and even bladder rectal disturbance. Repeated MRI after the onset failed to provide an imaging diagnosis. The MRI was performed 41 months after the onset and revealed a previously undiagnosed, contrast-enhancing spinal intramedullary neoplastic lesion at the Th11-12 level. Gross total resection of the tumor was successfully performed, and the pathology confirmed the diagnosis of pure germinoma. Postoperative chemotherapy, followed by local radiation, was successfully administered. Among primary germinomas of the CNS, occult germinoma that lacks imaging findings suggestive of tumors in the early stages of onset and becomes apparent over time is often reported as a primary neurohypophyseal germinoma, particularly in adolescents presenting with diabetes insipidus. In the present case, the lesion appeared to correspond to a primary occult germinoma of the intramedullary spinal cord.

Chronic expanding pituitary hematoma with calcification resulting from pituitary adenoma: illustrative case.

BACKGROUND: Pituitary apoplexy (PA) is characterized by sudden headache, vomiting, visual dysfunction, anterior lobe dysfunction, and endocrine disorder due to bleeding or infarction from a pituitary adenoma. PA occurs in approximately 0.6-10% of pituitary adenomas, more commonly in men aged 50-60 years, and more frequently in nonfunctioning and prolactin-producing pituitary adenomas. Further, asymptomatic hemorrhagic infarction is found in approximately 25% of PA. OBSERVATIONS: A pituitary tumor with asymptomatic hemorrhage was detected on head magnetic resonance imaging (MRI). Thereafter, the patient underwent head MRI every 6 months. After 2 years, the tumor was enlarged and visual dysfunction was noticed. The patient underwent endoscopic transnasal pituitary tumor resection and was diagnosed with a chronic expanding pituitary hematoma with calcification. The histopathological findings were very similar to those of chronic encapsulated expanding hematoma (CEEH). LESSONS: CEEH associated with pituitary adenomas gradually increases in size, causing visual dysfunction and pituitary dysfunction. In case of calcification, total removal is difficult due to adhesions. In this case, calcification developed within 2 years. A pituitary CEEH, even when showing calcification, should be operated on, as visual function can be fully recovered.

Influence of surgical position and registration methods on clinical accuracy of navigation systems in brain tumor surgery.

The aim of this study was to evaluate the influence of skin distortion due to surgical positioning on the clinical accuracy of the navigation system. The distance errors were measured in four fiducial markers (anterior, posterior, right, and left of the head) after the registration of the navigation system. The distance errors were compared between the surface-merge registration (SMR) method using preoperative imaging and the automatic intraoperative registration (AIR) method using intraoperative imaging. The comparison of the distance errors were performed in various surgical positions. The AIR method had the significant accuracy in the lateral markers than the SMR method (lateral position, 3.8 mm vs. 8.95 mm; p < 0.0001; prone position, 4.5 mm vs. 13.9 mm; p = 0.0001; 5.2 mm vs. 11.5 mm; p = 0.0070). The smallest distance errors were obtained close to the surgical field in the AIR method (3.25-3.85 mm) and in the forehead in the SMR method (3.3-8.1 mm). The AIR method was accurate and recommended for all the surgical positions if intraoperative imaging was available. The SMR method was only recommended for the supine position, because skin distortion was frequently observed in the lateral region.

The Safety of Spine Surgery in the Late-Stage Elderly of 75 Years of Age or Older: A Retrospective Multicenter Study.

OBJECTIVE: The objective of this study was to verify that spine surgery for late-stage elderly (LSE) (age 65-74 years) is as safe as that for early-stage elderly (ESE) (age 65-74 years). METHODS: This retrospective multicenter study included elderly patients aged ≥65 years who underwent spine surgery between 2018 and 2021. The medical information for individual patients was obtained from medical records. Activities of daily living (ADL) were estimated using a 5-grade scale based on the Eastern Cooperative Oncology Group performance status. Good outcome was defined as ADL grade 0 or 1 at discharge; poor outcome was defined as ADL grade 2 to 4 at discharge. The postoperative complications were listed with reference to the Common Terminology Criteria for Adverse Events v5.0. RESULTS: There were 311 patients in the ESE group and 395 patients in the LSE group. Reoperation during hospitalization was significantly higher in the LSE group (4.6%) than in the ESE group (1.6%). The total number of days of hospitalization was significantly longer in the LSE group than in the ESE group. However, there was no significant difference in the postoperative complications or ADL at discharge between the 2 groups. In the statistical analysis, preoperative American Society of Anesthesiologists physical status class 3-6, underlying heart or renal disease, and cervical or thoracic spine level of surgical procedures were significantly associated with poor ADL outcomes at discharge. CONCLUSIONS: Spine surgery even for LSE can be safely done, if perioperative risk factors are appropriately managed.

Ablation efficacy of 5-aminolevulinic acid-mediated photodynamic therapy on human glioma stem cells.

BACKGROUND: Cancer cells with stem cell-like features are generally more resistant to chemotherapy and radiotherapy than differentiated tumor cells. Thus, these cells tend to increase the propensity for tumor recurrence and metastasis. This study investigated the efficacy of 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) in destructing glioma stem cells (GSCs), including the mesenchymal subtype (MES-GSCs) demonstrated to have the lowest radio- and chemosensitivity. METHODS: Five high-grade glioma (HGG) GSC lines and derived differentiated glioma cell (DGC) lines were examined for protoporphyrin-IX (PpIX) expression using fluorescence-activated cell sorting (FACS) and then assessed for ALA-PDT sensitivity using cell viability assays. MES-GSCs surviving ALA-PDT were then isolated and evaluated for stem cell and mesenchymal marker expression levels (CD44, ALDH1A3, KLF4, nestin) by qRT-PCR. The ability of these surviving cells to form tumors was then examined using colony forming and by xenograft tumor assays in athymic mice. Finally, the relationship between PpIX expression level (high versus low) and ALA-PDT sensitivity was examined by FACS and colony forming assays. RESULTS: ALA-PDT was effective against all GSC lines including MES-GSCs. MES-GSC lines exhibited higher PpIX expression than derived DGCs. Surviving MES-GSCs demonstrated lower stem cell marker expression and tumor forming potential than naive MES-GSCs. Higher PpIX production capacity by MES-GSCs was associated with greater colony forming ability, and ALA-PDT was more effective against MES-GSCs with greater PpIX accumulation. CONCLUSION: ALA-PDT may be clinically effective against HGG by targeting GSCs, including MES-GSCs.

Coil embolization of the azygos anterior cerebral artery aneurysm: Three case reports.

The azygos anterior cerebral artery (ACA) is a rare anatomical anomaly. Clipping surgery has been conducted in approximately 30 reported cases because it is frequently associated with aneurysms. However, few cases in which coil embolization was performed have been reported. We report three cases of coil embolization for distal ACA aneurysms with distal azygos ACA at our institution in 7 years. All patients were over 65-year-old women with saccular aneurysms larger than 7 mm; two with subarachnoid hemorrhage and one with an unruptured aneurysm. No patient had surgical complications associated with coil embolization. Coil embolization is also useful for large aneurysms in the distal azygos ACA, and its indication for treatment could be broadened.