Distal stenting technique for coil embolization of early branch aneurysms of middle cerebral artery.

BACKGROUND AND PURPOSE: Stent-assisted coil embolization of early branch aneurysms of the middle cerebral artery (MCA) can sometimes be challenging due to the small diameter and acute angle of the branches. This study aimed to analyze the treatment results and report the feasibility and outcomes of the distal stenting technique for these aneurysms. MATERIALS AND METHODS: The distal stenting technique was used for 15 wide-neck MCA aneurysms (females, 10; males, 5; mean age, 65.1 years) originating from the early branch between December 2018 and October 2021. The average sizes of the dome, depth, and neck of the aneurysms were 4.17 mm (range: 2.99-6.21 mm), 2.86 mm (range: 1.82-3.72 mm), and 3.42 mm (range: 2.44-4.32 mm), respectively. RESULTS: The average diameter of the stents was 4.0 mm (3.0 mm, 3; 4.0 mm, 6; 4.5 mm, 6). Stents were successfully deployed in all 15 aneurysms (100%). The average length of the procedure was 69 min (range: 45-117 min). On postoperative angiography, nine (60.0%) aneurysms were completely occluded, four (26.7%) had neck remnants, and two (13.3%) had contrast flow in the sac. During the procedure, vasospasm and thrombus formation occurred in one case each, but no neurological sequelae were observed. On follow-up digital subtraction angiography of the 10 aneurysms after an average of 13.7 months (range: 12-18 months), the branches were well preserved, and neck remnants were noted in four aneurysms (40.0%). No thromboembolic events occurred during the clinical follow-up. CONCLUSION: The distal stenting technique using an open-cell stent can be a good option for coil embolization of early branch MCA aneurysms.

Usefulness of combination usage of balloon guide catheter with contact aspiration thrombectomy.

BACKGROUND: Angiographic outcomes of contact aspiration thrombectomy (CAT), a frontline thrombectomy strategy, can vary depending on balloon guide catheter (BGC) usage, stroke etiology, and occlusion location. The purpose of this study was to analyze conditional outcomes of CAT to determine which result in maximum angiographic benefits. METHODS: Patients who received CAT for anterior circulation occlusive stroke between January 2017 and December 2018 were included. Angiographic and clinical outcomes were compared relative to BGC use, stroke etiology, and occlusion location. Multivariable analyses for first-pass reperfusion (FPR) and favorable clinical outcome were performed. RESULTS: Of 160 included patients, the rates of FPR, successful reperfusion after CAT, final successful reperfusion, and favorable clinical outcome were 43.1%, 58.1%, 81.9%, and 60.6%, respectively. BGC use was associated with a higher rate of FPR, successful reperfusion after CAT, a lower rate of distal embolization, and faster reperfusion. Based on subgroup analysis, BGC usage in ICA, MCA M1 occlusion, and cardioembolism were associated with higher FPR, successful reperfusion after CAT, and lower distal embolization. Faster reperfusion was achieved in ICA occlusions and cardioembolisms. BGC usage was an independent predictor of FPR. Favorable clinical outcome was associated with male gender, low initial NIHSS score, fast onset to reperfusion, and FPR. CONCLUSIONS: In CAT, BGC usage was associated with better angiographic outcomes, including higher FPR, successful reperfusion after CAT, prevention of distal embolization, and faster reperfusion, especially in proximal occlusions and cardioembolisms. These conditions may play a role in maximizing the benefits of CAT.

Duration of Vasodilatory Action After Intra-arterial Infusions of Calcium Channel Blockers in Animal Model of Cerebral Vasospasm.

BACKGROUND: In medically refractory vasospasm, invasive intervention may be required. A commonly used approach is intra-arterial (IA) drug infusion. Although calcium channel blockers (CCBs) have been widely applied in this setting, studies comparing their efficacies and durations of action have been few. This study was performed to compare attributes of three CCBs (nicardipine, nimodipine, and verapamil), focusing on duration of the vasodilatory action based on angiography. METHODS: Vasospasm was produced in New Zealand white rabbits (N = 22) through experimentally induced subarachnoid hemorrhage and confirmed in each via conventional angiography, grouping them by IA-infused drug. After chemoangioplasty, angiography was performed hourly for 5 h to compare dilated and vasospastic arterial diameters. Drug efficacy, duration of action, and changes in mean arterial pressure (relative to baseline) were analyzed by group. RESULTS: Effective vasodilation was evident in all three groups immediately after IA drug infusion. The vasodilative effects of nimodipine and nicardipine peaked at 1 h and were sustained at 2 h, returning to initial vasospastic states at 3 h. In verapamil recipients, effects were more transient by comparison, entirely dissipating at 1 h. Only the nicardipine group showed a significant 3-h period of lowered blood pressure. CONCLUSIONS: Although nimodipine and nicardipine proved longer acting than verapamil in terms of vasodilation, their effects were not sustained beyond 2 h after IA infusion. Further study is required to confirm the vasodilatory duration of IA CCB based on perfusion status, and an effort should be made to find new alternative to extend the duration.

Retrograde stenting through anterior communicating artery in coil embolization of the posterior communicating artery aneurysm: contralateral approach.

During coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms, stent assistance is sometimes limited if PcomA is acutely angled at its origins from saccular neck. Herein, we present two instances where retrograde stenting was used for coil embolization of PcomA aneurysms. Both procedures involved a contralateral approach via anterior communicating artery (AcomA). To achieve this, the stent-delivery microcatheter was inserted retrograde from contralateral to ipsilateral internal carotid artery (ICA) across AcomA, arriving at ipsilateral PcomA. A separate microcatheter, passed through ipsilateral ICA, was then used to select the aneurysm sac for coil delivery. Coil embolization ultimately took place under protection of a horizontally placed stent extending from PcomA to terminal ICA. Each aneurysm was properly coiled and occluded, without procedural complications. This stenting technique is a reasonable option, offering a means of strategic coil embolization in wide-necked PcomA aneurysms and providing complete neck coverage through contralateral access.

Simultaneous neck coverage and branch preservation using the proximal portion of a self-expandable open-cell stent for embolization of distal internal carotid artery aneurysms: multi-center, long-term results.

PURPOSE: We report the long-term results of a modified stent-assisted coil embolization technique using the far proximal part of a self-expanding open-cell stent. The technique was used to cover the neck of the aneurysm while simultaneously preserving the branches of the distal internal carotid artery in patients with aneurysms of the posterior communicating (Pcom) and anterior choroidal arteries (AchA). METHODS: We performed a retrospective review of the prospectively maintained databases at two tertiary neurosurgical centers to identify all patients who underwent embolization of Pcom or AchA aneurysms using this technique between January 2014 and July 2019. Postoperative and follow-up clinical and radiological results for initial (n = 16) or re-do (n = 4) embolizations were analyzed. RESULTS: We identified 19 patients with 20 (16 Pcom and 4 AchA) unruptured (n = 19) or ruptured (n = 1) aneurysms. Eighteen among 20 stents (90.0%) were deployed successfully, and complete occlusions were initially attained in 18 aneurysms (90.0%). At follow-up examinations 8 to 56 months later, 6 of 14 aneurysms (42.8%) showed neck remnants. All of the branches were saved and no thromboembolic event, rupture, or sequelae were noted during or after the procedures. CONCLUSION: These results suggest that this modified stent-assisted technique is a feasible and reasonable alternative to conventional stent deployment for coil embolization of wide-necked sidewall aneurysms in the distal ICA.

Is arachnoid cyst a static disease? A case report and literature review.

INTRODUCTION: The increasing use of intracranial imaging has led to more frequent diagnoses of arachnoid cysts (ACs). Although ACs are a frequent finding on neuroimaging in children, the prevalence and natural history of these cysts are not well defined. Most ACs may persist and remain asymptomatic throughout life and not require treatment. However, there have been some case reports of ACs that have become larger or smaller over time and, in rare cases, have even spontaneously resolved. It is the authors' practice to recommend serial neuroimaging in patients with asymptomatic sylvian ACs and not offer surgery to patients without symptoms, even in those with a relatively large cyst. CASE REPORT: The present article describes a case involving a 6-year-old boy with a large, asymptomatic AC in the left Sylvian fissure involving the temporo-frontal region, which resolved spontaneously during the 2-year follow-up period after initial diagnosis without any surgical intervention. Currently, at the 7-year follow-up, the patient has remained neurologically intact, attends school, and is symptom-free. CONCLUSION: Clinicians should be mindful of the possibility of spontaneous regression when encountering patients with asymptomatic and/or incidentally diagnosed sylvian ACs.

Use of microcatheters for suction thrombectomy of acute distal occlusions.

We report our initial experience of using a microcatheter for contact aspiration of acute distal occlusions for recanalization. Endovascular technique and a case using Excelsior XT-27 microcatheter are presented. After manual suction within distal middle cerebral artery segments using a 50-ml syringe, instant and complete recanalization was obtained. Microcatheter suction thrombectomy using a 50-ml syringe can be considered a feasible treatment option for acute distal small artery occlusions.

The Effect of Inter-Departmental Stroke Meetings on Rehabilitation in a Comprehensive Cerebrovascular Center.

BACKGROUND: Stroke is the number one cause of adulthood disability in Korea. Rehabilitation after stroke can minimize functional disability, enhance recovery toward independence, and optimize community reintegration. The inter-departmental stroke meeting (IDSM) is a potential method to improve rehabilitation outcomes in patients with stroke. We aimed to analyze the effect of IDSM on rehabilitation after acute ischemic stroke management. METHODS: Medical records of 753 patients with acute ischemic stroke admitted to the neurology department of our medical center between January and December 2014 were reviewed retrospectively. In May 2014, weekly IDSMs were initiated. All physicians responsible for the patient's care reviewed patient treatment, methods of secondary prevention, and future rehabilitation plans. RESULTS: The transfer rate significantly increased after initiation of IDSM (phase 2, 3) and the length of stay (LOS) before transfer to the rehabilitation department decreased significantly from 9.68 ± 8.50 days to 5.75 ± 2.12 days. There was a reduction in the total LOS from 52 ± 28.57 days to 35 ± 27.21 days after IDSMs were introduced. In non-transferred patients also, the total LOS reduced significantly. The transfer rate increased significantly and the LOS before transfer to the rehabilitation department decreased significantly after implementation of IDSM in a subgroup of patients with moderate to severe stroke. CONCLUSION: The introduction of IDSM was significantly correlated with improvements in transfer rates and reduction of LOS in hospital. This finding shows that IDSMs are an important intervention to improve therapeutic progress and outcomes for patients with stroke.

Nafamostat mesilate promotes endothelium-dependent vasorelaxation via the Akt-eNOS dependent pathway.

Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest that NM increases NO generation via the Akt/eNOS signaling pathway, leading to endothelium-dependent vascular relaxation. Therefore, the vasorelaxing action of NM may contribute to the regulation of cardiovascular function.

Modified protection using far proximal portion of self-expandable closed-cell stents for embolization of wide-necked intracranial aneurysms.

INTRODUCTION: Stent-assisted embolization is sometimes limited in wide-necked aneurysms involving the acute-angled origins of tortuous branching arteries, and occasionally, Y-shaped stenting is required to remedy the sweeping effects of a broad aneurysmal neck on arterial branches. Described herein is a modified stent-assisted coil embolization technique entailing strategic placement of far proximal stent ("distal stenting") as an alternate approach in such scenarios. METHODS: For this particular technique, stent placement is confined to a branch artery, allowing far proximal stent to cover aneurysmal neck, with no bridge to parent artery. Kinking of stents deployed in tortuous arteries is thereby avoided, and better coverage of aneurysmal neck is achieved, compared with traditional stent protection. Records of 12 consecutive patients with wide-necked aneurysms, all treated by coil embolization with distal stenting between January 2009 and February 2014, were retrieved from a prospective data repository at our institution. Outcomes were analyzed in terms of morphologic features and clinical status. RESULTS: This modified technique was largely applied to aneurysms of middle cerebral artery, followed by posterior communicating artery and anterior communicating artery sites. With one exception, all aneurysms treated were successfully occluded. There were no complications directly related to distal stenting. At final follow-up (mean interval, 16.8 ± 9.7 months), complete aneurysmal occlusion was sustained in 81.8%. Delayed stent migration was observed in one patient (8.3%). CONCLUSION: Our study suggests that distal stenting in wide-necked aneurysms is a reasonable alternative to traditional stent protection, despite the potential for delayed stent migration.

Suction thrombectomy of distal medium vessel occlusion using microcatheter during mechanical thrombectomy for acute ischemic stroke: A case series.

While mechanical thrombectomy is known to be effective for distal medium vessel occlusion (DMVO) as well as large vessel occlusion, tortuous DMVO are predisposed to vessel injury during stent retriever thrombectomy. Furthermore, getting access to the thrombus may be difficult during suction thrombectomy using a dedicated suction catheter. Most studies describe DMVO treatment using stent retrievers and dedicated suction catheters, but there are limited studies reporting DMVO treated with suction thrombectomy using a microcatheter. Herein, we describe three cases of DMVO treated with suction thrombectomy that was performed using a microcatheter and subsequently showed good results. Therefore, suction thrombectomy using a microcatheter is a viable alternative treatment for tortuous DMVO.

Endovascular recanalization therapy for patients with acute ischemic stroke with hidden aortic dissection: A case series.

Aortic dissection is one of the causes of acute ischemic stroke. Endovascular recanalization therapy (EVT) has emerged as an essential treatment for acute ischemic stroke due to large artery occlusion. However, it is rarely performed in the situation of hidden aortic dissection (AD). Two patients presented to the emergency room with focal neurologic deficits. The first patient was diagnosed with right internal carotid artery (ICA) occlusion. Angiography revealed that the ICA was occluded by the dissection flap. After a stent deployment in the proximal ICA, the antegrade flow was restored. The patient was diagnosed with AD on chest computed tomography (CT) after EVT. For the second patient, intraarterial thrombectomy was performed to treat left middle cerebral artery occlusion. AD was first detected on echocardiography, which was performed after EVT. Herein, we report successful endovascular recanalization therapy performed in two patients with acute ischemic stroke in the situation of undiagnosed aortic dissection. We also reviewed previous case reports and relevant literature.

Role of Adjunctive Tranexamic Acid in Facilitating Resolution of Chronic Subdural Hematoma after Surgery.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common neurosurgical disease and generally treated with burr-hole surgery alone. Tranexamic acid (TXA) is an antifibrinolytic agent that potentially reduces recurrence rates and the residual hematoma volume. However, the role of postoperative TXA medication remains unclear to date. This study aimed to verify the effectiveness of adjunctive TXA in the view of early hematoma resolution. METHODS: Between January 2018 and September 2021, patients with CSDH who underwent burr-hole trephination in a single tertiary institute were reviewed. The study population was divided into three groups, TXA, non-TXA, and antithrombotics (AT) groups, according to the medical history of cardio-cerebrovascular disease and TXA administration. The primary endpoint was CSDH recurrence, defined as re-appearance or re-accumulation of CSDH requiring neurosurgical interventions. The secondary outcome was CSDH resolution, defined as complete or near-complete resorption of the CSDH. The CSDH resolution time and serial changes of hematoma thickness were also investigated. RESULTS: A total of 240 patients was included in the analysis consisting of 185 male and 55 female, with a median age of 74 years. During the median imaging follow-up period of 75 days, 222 patients were reached to the primary or secondary endpoint. TXA was administered as an adjunctive therapy in 41 patients (TXA group, 16.9%) while 114 patients were included in the non-TXA group (47.9%) and 85 were in the AT group. The recurrence rate was the lowest in the TXA group (2.4%), followed by non-TXA (7.0%) and AT (8.2%) groups. However, there was no statistical significance due to the small number of patients with recurrence. CSDH resolution was achieved in 206 patients, and the median estimated time to resolution was significantly faster in the TXA group (p<0.001). Adjunctive TXA administration was a significant positive factor for achieving CSDH resolution (p<0.001). The hematoma thickness was comparable among the three groups at the initial time and after surgery. However, CSDH thickness in the TXA group decreased abruptly in a month and showed a significant difference from that in the other groups (p<0.001). There was no TXA-related adverse event. CONCLUSION: The adjunctive use of TXA after CSDH surgery significantly facilitated the resorption of residual CSDH and resulted in the early CSDH resolution. Adjunctive TXA may be an effective treatment option to reduce recurrence by enhancing CSDH resolution in the selective patients.

Risk factor analyses of contrast leakage and contrast-induced encephalopathy following coil embolization for unruptured intracranial aneurysm.

BACKGROUND: Contrast-induced encephalopathy (CIE) following endovascular interventions is a rare but serious complication. This study aimed to investigate the risk factors of contrast leakage (CL) and CIE in patients who underwent coil embolization of unruptured intracranial aneurysms (UIAs). METHODS: Patients with UIAs who underwent coil embolization at a single tertiary institute between January 2019 and January 2022 were enrolled retrospectively. CL was defined as cortical or subcortical contrast enhancement with effacement of the cortical sulci. CIE was defined as the new onset of neurological deficits associated with CL. Following the procedure, all patients underwent CT scans, and MRI scans were performed on those with symptoms. Patient and procedural risk factors were investigated. RESULTS: In total, 459 patients were analyzed. The median procedure time and contrast dose were 69 min and 96 mL, respectively. CL was evident in 35 patients. In the multivariate analysis, hypertension, large aneurysm, longer procedure time, and greater contrast dose were associated with CL. CIE was diagnosed in 19 patients, and the risk factors included large aneurysm, longer procedure time, and greater contrast dose. The procedure time was predictive of both CL (P<0.001) and CIE (P=0.01). The optimal cut-off value for procedure time was 81.5 min. All CIE patients recovered completely within 8-96 hours. CONCLUSIONS: A large aneurysm and prolonged procedure time may increase the patient's risk of CL and CIE due to increased contrast exposure. Patients who underwent a procedure that exceeded 1.5 hours necessitate post-procedure evaluation and monitoring.

Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms: a nationwide registry study.

BACKGROUND: Antiplatelet therapy, where regimens are tailored based on platelet function testing, has been introduced into neurointerventional surgery. This nationwide registry study evaluated the effect and safety of tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms compared with conventional therapy using a standard regimen. METHODS: This study enrolled 1686 patients in 44 participating centers who received stent assisted coiling for unruptured aneurysms between January 1, 2019 and December 31, 2019. The standard regimen (aspirin and clopidogrel) was used for all patients in the conventional group (924, 19 centers). The regimen was selected based on platelet function testing (standard regimen for clopidogrel responders; adding cilostazol or replacing clopidogrel with other thienopyridines (ticlopidine, prasugrel, or ticagrelor) for clopidogrel non-responders) in the tailored group (762, 25 centers). The primary outcome was thromboembolic events. Secondary outcomes were bleeding and poor outcomes (increase in modified Rankin Scale score). Outcomes within 30 days after coiling were compared using logistic regression analysis. RESULTS: The thromboembolic event rate was lower in the tailored group than in the conventional group (30/762 (3.9%) vs 63/924 (6.8%), adjusted OR 0.560, 95% CI 0.359 to 0.875, P=0.001). The bleeding event rate was not different between the study groups (62/762 (8.1%) vs 73/924 (7.9%), adjusted OR 0.790, 95% CI 0.469 to 1.331, P=0.376). Poor outcomes were less frequent in the tailored group (12/762 (1.6%) vs 34 (3.7%), adjusted OR 0.252, 95% CI 0.112 to 0.568, P=0.001). CONCLUSION: Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms reduced thromboembolic events and poor outcomes without increasing bleeding.

A Deep Neural Network-Based Model Predicting Peritumoral Edema After Radiosurgery for Meningioma.

BACKGROUND: Gamma Knife radiosurgery (GKS) is a promising treatment option for meningioma. However, the incidence of peritumoral edema (PTE) following GKS has been reported to be 7%-38%. This study aimed to develop a predictive model for post-GKS PTE using a deep neural network (DNN) algorithm. METHODS: Patients treated with GKS for meningioma between November 2012 and February 2020 at a single tertiary center were reviewed. The primary outcome was newly developed or aggravated PTE after GKS. Clinical data, including radiosurgical parameters, were collected, and imaging data obtained at the time of GKS were incorporated into the model using a 50-layered residual neural network, ResNet50. Consequently, the model efficiency was evaluated considering the accuracy and area under the receiver operating curve (AUC) values. RESULTS: A total of 202 patients were included in this study. The median tumor volume was 2.3 mL, and the median prescription dose was 13 Gy. PTE was observed before GKS in 22 patients. Post-GKS PTE was evident in 28 patients (13.9%), which further evolved to radiation necrosis in 5 patients. The accuracy and AUC values of the hybrid data model based on both clinical and imaging data were 0.725 and 0.701, respectively. The performance of the hybrid data model was superior to that of the other models based on clinical or image data only. CONCLUSIONS: The DNN-based model using both clinical and imaging data exhibited fair results in predicting post-GKS PTE in meningioma treatment. Predictive models using imaging data may be helpful in prognostic research.

Reverse Trans-Sellar Neuroendoscopic Management of a Large Rathke's Cleft Cyst Causing Obstructive Hydrocephalus: A Case Report.

Symptomatic Rathke's cleft cysts (RCCs) can be treated by surgical procedures, usually through an endonasal transsphenoidal corridor using either a microscope or an endoscope. We report a large suprasellar extended RCC causing obstructive hydrocephalus, which was efficiently managed by a novel surgical route named "reverse" trans-sellar approach using transventricular neuroendoscopy. A 48-year-old woman complained of persistent headache and a tendency to fall that had begun 6 months previously. The images obtained from MRI scan showed intra- and supra-sellar cystic masses occupying the third ventricle with obstruction of the foramina of Monro and the aqueduct of Sylvius. The cystic wall showed a slight enhancement, and the cystic contents showed iso-signal intensity on T1-and T2-weighted images. Instead of trans-nasal trans-sellar surgery, we decided to operate using a conventional transventricular endoscope. A thin cystic capsule, which blocked the foramina of Monro and the aqueduct of Sylvius, was fenestrated and removed and a third ventriculostomy was performed. The defect in the infundibulum between sellar and suprasellar cysts was widened and used as a corridor to drain cystic contents (reverse trans-sellar route). The final pathological finding revealed an RCC with focal metaplasia. We efficiently managed a large RCC by transventricular neuroendoscopic surgery with cyst fenestration and third ventriculostomy and simultaneously drained the sellar contents using a novel surgical route. Reverse trans-sellar neuroendoscopic surgery is a relevant treatment option for selective patients with large suprasellar extensions of RCCs.

Rotational Vertebral Artery Syndrome (Bow Hunter's Syndrome): A Rare Differential Diagnosis in Patients With Syncope.

Syncope is a common symptom in clinical practice. Rotational vertebral artery occlusion syndrome, also referred to as Bow Hunter's syndrome (BHS), is a rare condition associated with syncope and is caused by mechanical occlusion or stenosis secondary to mechanical compression of the vertebral artery during head rotation. BHS is associated with a multifactorial etiology; however, in most cases, this condition is attributed to degenerative changes. A 53-year-old man visited our hospital for the evaluation of fainting and dizziness episodes that occurred when he turned his head. Evaluation as an outpatient in the Department of Neurology showed a positive result on the Frenzel goggle test. Transfemoral cerebral angiography performed at the Department of Neurosurgery revealed stenosis of the proximal right vertebral artery. Complete occlusion of the vertebral artery was observed, and the head was turned to the right. Decompression and fusion were performed, and the contributory lesion was completely removed. Postoperative imaging confirmed complete removal of the spur and sufficient vertebral artery decompression; the patient's symptoms resolved postoperatively.

A Huge Radiation-Induced Cavernous Hemangioma Following Stereotactic Radiosurgery for Meningioma: A Case Report.

Radiation-induced cavernous hemangiomas (RICHs) have been increasingly reported as a late complication after conventional radiotherapy. RICH after stereotactic radiosurgery (SRS) is extremely rare and the few cases have been reported to demonstrate their properties. A 72-year-old female patient presented with progressive neurologic deficits. She underwent tumor surgery for meningioma 13 years ago and two times of SRS for treating a residual tumor. Newly-developed mass was 4.3 cm-sized heterogeneously enhancing mass with severe cerebral edema. She underwent surgical resection and the histologic examinations revealed organized hematoma. Finally, it was diagnosed as a RICH following SRS based on radiological and histological findings and a history of multiple radiosurgeries. Clinical, radiological, and histological features of a RICH following SRS were discussed in this report.

Treatment results of anterior choroidal artery aneurysms treated mostly with coil embolization: A single-center experience.

BACKGROUND: Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute. METHODS: The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute. RESULTS: In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6-174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed. CONCLUSIONS: The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.