Ulceration location is associated with clinical course in carotid stenosis.

OBJECTIVE: Plaque ulceration in carotid artery stenosis is a risk factor for cerebral ischemic events; however, the characteristics that determine plaque vulnerability are not fully understood. We thus assessed the association between plaque ulceration sites and cerebrovascular ischemic attack. METHODS: We retrospectively collected the clinical data of 72 consecutive patients diagnosed with carotid artery stenosis with plaque ulcers. After excluding patients with pseudo-occlusion, a history of previous carotid endarterectomy or carotid artery stenting before the ulcer was first discovered, follow-up data of less than 1 month, or carotid endarterectomy or carotid artery stenting performed within 1 month after the ulcer was first discovered, 60 patients were ultimately included. Patients were divided into proximal and distal groups based on the ulcer location relative to the most stenotic point. The primary endpoints were ipsilateral cerebrovascular ischemic events ("ischemic events"), such as amaurosis fugax, transient ischemic attack, or ischemic stroke due to carotid artery stenosis with plaque ulceration. The association between ulcer location and ischemic events was also assessed. RESULTS: In the patients with plaque ulcer, more patients had proximal than distal plaque ulcers (39 vs 21; P = .028). The median follow-up duration was 3.8 years (interquartile range, 1.5-6.2 years). Nineteen patients (32%) experienced ischemic event. Ischemic events occurred more frequently in the distal than in the proximal group (18% vs 59%; P = .005). Kaplan-Meier curves demonstrated a significantly shorter event-free time in the distal group (log-rank P = .021). In univariate analysis, distal ulcer location was associated with ischemic events (odds ratio [OR], 2.94; 95% confidence interval [CI], 1.13-7.65; P = .03). Multivariate analysis using two different models also showed that distal ulcer location was independently associated with ischemic events (Model 1: OR, 3.85; 95% CI, 1.26-11.78; P = .03; Model 2: OR, 4.31; 95% CI, 1.49-12.49; P = .009). CONCLUSIONS: Patients with carotid artery stenosis and plaque ulcers located distal to the most stenotic point are more likely to experience cerebrovascular ischemic attacks. Therefore, carotid plaques with ulcers located distal to the most stenotic point may be a potential indication for surgical treatment.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

Irreversible postoperative cognitive impairment after unruptured intracranial aneurysm treatment in the elderly.

PURPOSE: Postoperative cognitive dysfunction and recovery remain unclear in older patients undergoing interventional therapies for unruptured intracranial aneurysms (UIAs). This study aimed to compare changes in postoperative cognitive function between younger and older patients and to detect factors associated with non-recovery from postoperative cognitive dysfunction. METHODS: This study reviewed 59 consecutive patients with UIAs who underwent interventional therapies, including microsurgical clipping or endovascular treatment, from 2021 to 2022. All patients were divided into the older (aged ≥ 70 years) and younger (aged < 70 years) groups. Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) were performed within 2 months before interventions, at 1 week postoperatively (POW1), and 3-6 months postoperatively (POM3-6). RESULTS: MMSE and FAB scores decreased more frequently in the older group than in the younger group at POW1 (older vs. younger: MMSE: 48% vs. 21%, p < 0.05; FAB: 56% vs. 18%, p < 0.01). In the older group, the FAB Z-score decreased in POW1 and recovered by POM3-6 (p < 0.01), while the MMSE Z-score continued to decrease (p = 0.04). Age and the preoperative MSME Z-score were significantly associated with non-recovery from decreased MMSE score at POM3-6 (recovery vs. non-recovery, age: 62 years old vs. 72 years old, p = 0.03, preoperative MMSE Z-score: 0.16 vs. - 0.90, p < 0.01). CONCLUSIONS: This retrospective study found that older patients were more likely to have a postoperative cognitive decline after UIA treatment and implicated that global cognitive function tended to decline more than executive function in the long term. In addition, this study demonstrated that lower preoperative cognitive function was associated with inadequate postoperative cognitive recovery. The findings potentially contribute to the establishment of indications for treating UIAs in older patients.

Impact of tailored multimodal treatment for unruptured brain arteriovenous malformation: comparison with a randomized trial of unruptured brain arteriovenous malformations.

PURPOSE: The first randomized controlled study on unruptured brain arteriovenous malformations (bAVM), the ARUBA trial, demonstrate the superiority of medical management; however, it failed to completely rule out the efficacy of therapeutic interventions due to several limitations. This study aimed to examine the outcomes of multimodal interventional treatment for bAVM in terms of safety and efficacy. METHODS: We reviewed 226 consecutive patients with unruptured bAVM admitted to our institute between 2002 and 2022. Treatment methods were divided into medical management and therapeutic intervention, including microsurgery, stereotactic surgery, and endovascular intervention. First, the choice of therapeutic modalities was assessed in the pre-ARUBA (before February 2014) and post-ARUBA (after March 2014) eras. Second, the incidence of symptomatic stroke or death and functional prognosis with a modified Rankin scale (mRS) score of ≥2 at 5 years was compared between the medical management and therapeutic intervention. RESULTS: In the pre- and post-ARUBA groups, 73% and 84% of patients underwent therapeutic interventions, respectively (p = 0.053). The rate of symptomatic stroke or death was lower in patients who underwent interventional therapies than in those who underwent medical management (9.7% vs. 22%, p = 0.022); however, the opposite was observed in the ARUBA trial (31% vs. 10%). The annual incidence of stroke or death was also lower in the interventional therapy group (4.3%/y vs. 1.8%/year, hazard ratio = 0.45, 95% confidence interval: 0.18-1.08, p = 0.032). The rate of mRS score of ≥2 after a 5-year follow-up was 18% and 6% in the medical treatment and intervention groups (p = 0.14). CONCLUSIONS: The therapeutic intervention rate did not decrease, even after the publication of the ARUBA trial. The rate of stroke or death was lower in the intervention group, indicating that a tailored choice of multimodality is safe and effective for managing unruptured bAVM.

[Changes in Gamma Knife Radiosurgery(GKRS)in Patients with Metastatic Brain Tumors before and after COVID-19].

The spread of coronavirus disease 2019(COVID-19)is a concern as it may delay the detection of malignant tumors due to delayed medical checkups. We examined changes in the treatment of metastatic brain tumors before and after COVID- 19. A retrospective review of 211 patients with metastatic brain tumors who underwent initial gamma knife radiosurgery between July 2019 and December 2021 was conducted. Data collected include patient age, gender, the Karnofsky performance status(KPS), primary tumor control, number, total volume, and outcome during the COVID-19 emergency declaration period and outside of it. The patient number was 164 outside of the emergency period and 47 during the period. Symptomatic cases(KPS<90)and poor control of the primary site increased during the COVID-19 period. The treatment number and volume of brain metastasis did not change. Metastatic control after 4 months of treatment also showed no difference. The number of symptomatic patients increased during the emergency declaration period, suggesting that COVID- 19 may have reduced the rate of asymptomatic patients being seen. However, these were not enough to affect the prognosis at 4 months. Overall, the COVID-19 pandemic had a small impact on the provision of stereotactic radiotherapy for metastatic brain tumors.

Intracranial arterial stenosis associated with Hashimoto's disease: angiographic features and clinical outcomes.

BACKGROUND: Hashimoto's disease has reportedly been associated with stroke; however, cerebrovascular morphology and clinical course remain poorly documented. The present study aimed to determine the angiographic features and clinical outcomes of intracranial arterial stenosis (IAS) associated with Hashimoto's disease in a retrospective cohort. METHODS: Overall, 107 adult patients with IAS were screened for anti-thyroid antibodies; of these, 26 patients tested positive. The 42 affected hemispheres were classified into subgroups according to the steno-occlusion site and the development of abnormal collateral (moyamoya) vessels. These subgroups were dichotomized into moyamoya vessels positive (MM type) and negative (non-MM type). The initial presentation, IAS progression, and vascular events during the follow-up period were compared. RESULTS: The following sites of stenosis were identified: the bifurcation of the internal carotid artery in 11 (26.2%), M1 or A1 in 29 (69.0%), and more distal (M2-M4/A2-A4) in 2 (4.8%) hemispheres. Further, 17 hemispheres were categorized into the MM type and 25 were classified into the non-MM type. During the follow-up period (mean 2.5 years), IAS progression was identified in 8 (32%) hemispheres of the non-MM type and 0 (0%) hemispheres of the MM type (p = 0.041). Ischemic attacks occurred in 5 (20.0%) hemispheres of the non-MM type (4.6%/year) and 0 hemispheres of the MM type (p = 0.08). Further, 4 (23.5%) hemispheres of the MM type experienced intracerebral hemorrhage, whereas none of the non-MM type hemorrhaged (p = 0.012). CONCLUSIONS: Hashimoto's disease-associated IAS exhibits various angiographic morphologies, resulting in different clinical presentations. Screening for anti-thyroid antibodies and careful management based on vascular morphology appears important in adults with IAS.

Difference in periventricular anastomosis in child and adult moyamoya disease: a vascular morphology study.

BACKGROUNDS: Periventricular anastomosis (PA), which is a novel term for extended collateral vessels in moyamoya disease (MMD), is reportedly associated with a high risk of intracranial hemorrhage in adult patients. The present study aimed to clarify the similarities and the differences in the development of PA between three MMD groups, classified by age at the time of diagnosis and clinical phenotype. METHODS: This study included 232 hemispheres of 132 patients with MMD who underwent surgical revascularization. The subjects were classified into child ischemic (CI) group, adult ischemic (AI) group, and adult hemorrhagic (AH) group. We evaluated the lenticulostriate (LSA), thalamic (THA), choroidal (ChA), anterior choroidal (AChA), and posterior choroidal (PChA) anastomosis as well as the posterior cerebral artery (PCA) involvement. The PA scores and the sums of each grade of LSA, THA, and ChA anastomosis were also calculated in all of the cases. RESULTS: In a multiple comparison test, the PA scores (P < 0.01), LSA (P < 0.01), and ChA anastomosis (P = 0.013) were more prominent in the CI than in the AI group. The PA scores (P < 0.01) and LSA (P = 0.011), ChA (P < 0.01), AChA (P < 0.01), and PChA anastomosis (P = 0.016) were more prominent in the AH group than in the AI group. The CI and AH groups showed similar characteristics except for PCA involvement. After multivariate adjustments using the AI group as a reference group, the PA scores and the positive rates of LSA and ChA anastomosis remained significantly higher in the CI and AH groups. CONCLUSION: The patterns of PA development in the CI and AH groups were similar in that they were more prominent than in the AI group. These findings may contribute to a better understanding of the progression of ischemic and hemorrhagic MMD.

Multimodal Interventional Treatment and Outcomes for Unruptured Arteriovenous Malformations.

BACKGROUND: This study aimed to evaluate the selection and outcomes of multimodal interventional treatment for unruptured brain arteriovenous malformations (uAVMs) in ARUBA-eligible patients in a single institution. METHODS: We retrospectively reviewed the data of 94 patients with uAVMs treated between 2002 and 2014. They were divided into an intervention group and a conservative group. The primary outcome was defined as the composite of death or symptomatic stroke. Functional outcome was assessed using the modified Rankin Scale (mRS). RESULTS: The intervention and conservative groups included 75 and 19 patients, respectively, with mean follow-up periods of 59.2 ± 41.6 and 72.8 ± 39.2 months (P = 0.20), among whom the primary outcome occurred in 9 (12.3%) and 3 (17.6%) patients, respectively (P = 0.91). The proportion of patients with an mRS score ≥ 2 at last follow-up was not significantly different between the two groups (6.9% vs. 11.7%). In the intervention group, the incidence of death or stroke was lower and functional outcomes were better among patients with grade I/II AVMs than among patients with grade III AVMs. CONCLUSION: For patients with uAVMs, interventional treatment is not inferior to medical treatment alone, and careful selection should be made for patients with grade III AVMs.

Management of pregnancy complicated with intracranial arteriovenous malformation.

AIM: To clarify the perinatal outcomes in pregnancy complicated with intracranial arteriovenous malformation (i-AVM). METHODS: A retrospective study was performed in 36 pregnancies complicated by i-AVM from 1981 to 2013 at one institution. RESULTS: In total, 6 women miscarried, and 30 had live births. The median (range) gestational age at delivery was 38 (24-40) weeks; 11 cases experienced initial i-AVM rupture during pregnancy (first, second and third trimester: 18%, 64% and 18%, respectively). At onset, 4 cases had a Glasgow Coma Scale ≤10, 10 cases needed emergency maternal transport, 4 underwent neurosurgery with the fetus in utero and 4 had termination of pregnancy in the second trimester for emergent treatment for i-AVM. Two cases delivered vaginally. Another 25 cases had already been diagnosed as i-AVM at conception. Of these, as an indication for epidural birth, 18 cases had either residual lesion of i-AVM or neurological symptoms, although 18 cases had received treatments of i-AVM before conception. Without rupture of i-AVM and worsening of symptoms, 15 cases succeeded in epidural birth. One case was delivered by cesarean section for residual i-AVM with indication of treatment. Another case who had refused treatment of i-AVM experienced rupture of i-AVM 1 year after delivery. CONCLUSION: Most of the cases with residual i-AVM lesion and neurological symptoms could deliver vaginally without worsening of symptoms. However, pregnancy with i-AVM can be complicated by rupture of i-AVM. In cases with a residual lesion with indication of treatment and rupture of i-AVM during pregnancy, meticulous care is required during pregnancy and after delivery.

Construction of 3 animal experimental models in the development of honeycomb microporous covered stents for the treatment of large wide-necked cerebral aneurysms.

The treatment of large or wide-necked cerebral aneurysms is extremely difficult, and carries a high risk of rupture, even when surgical or endovascular methods are available. We are developing novel honeycomb microporous covered stents for treating such aneurysms. In this study, 3 experimental animal models were designed and evaluated quantitatively before preclinical study. The stents were prepared using specially designed balloon-expandable stents (diameter 3.5-5.0 mm, length 16-28 mm) by dip-coating to completely cover their struts with polyurethane film (thickness 20 µm) and microprocessing to form the honeycomb pattern after expansion. (1) In an internal carotid artery canine model (n = 4), all stents mounted on the delivery catheter passed smoothly through the tortuous vessel with minimal arterial damage. (2) In an the large, wide-necked, outer-sidewall aneurysm canine model, almost all parts of the aneurysms had embolized immediately after stenting (n = 4), and histological examination at 2 months revealed neointimal formation with complete endothelialization at all stented segments and entirely organized aneurysms. (3) In a perforating artery rabbit model, all lumbar arteries remained patent (n = 3), with minimal change in the vascular flow pattern for over 1 year, even after placement of a second, overlapping stent (n = 3). At 2 months after stenting, the luminal surface was covered with complete thin neointimal formation. Excellent embolization performance of the honeycomb microporous covered stents without disturbing branching flow was confirmed at the aneurysms in this proof-of-concept study.

A Review of Current Flow Diverters.

Flow diverter (FD) devices are new-generation stents placed in the parent artery at the aneurysmal neck to obstruct intra-aneurysmal blood flow, thus favoring intra-aneurysmal thrombosis. In Japan, about eight years have passed since health insurance approval was granted for FD devices, and FD placement to treat aneurysms has become widespread. Treatment indications have also been expanded with the introduction of novel devices. At present, three types of FD (Pipeline, FRED, and Surpass Streamline) are available in Japan. This report represents a compilation of available FD technologies and describes the current consensus on this treatment.

Plaque Ulcerations are Associated with Recurrence in Symptomatic Low-Grade Carotid Stenosis.

OBJECTIVE: Surgical indications for low-grade carotid stenosis have not yet been established. This study aimed to clarify the characteristics of low-grade carotid stenosis refractory to medical treatment. METHODS: We retrospectively analyzed 48 patients with symptomatic low-grade carotid stenosis (<50%). Recurrence was defined as an ipsilateral ischemic event in the symptomatic lesions during the follow-up period. Patient demographics and imaging findings were compared between the recurrence and nonrecurrence groups to investigate risk factors associated with medical treatment. RESULTS: The mean age was 74.1 (58-90 years), and the mean follow-up period was 35.4 months (2.0-97 months). Recurrence occurred in 15 of the symptomatic patients. Ulceration was significantly associated with recurrence under medical treatment (P = 0.001). The median time to recurrence was 26.1 months in patients with ulcers and 54.3 months in those without ulcers (P = 0.04). Pathological study with recurrence showed plaque rupture with multilayered lesions, indicating lesions refractory to medical treatment. CONCLUSIONS: In cases of low-grade carotid stenosis, lesions with ulcerations are likely refractory to medical therapy. Consideration of the indications for surgical treatment may be warranted for lesions with ulceration, even if the degree of stenosis is low.

Hemodynamic differences determining rupture and non-rupture in middle cerebral aneurysms after growth.

BACKGROUND AND PURPOSE: Intracranial aneurysm growth is a significant risk factor for rupture; however, a few aneurysms remain unruptured for long periods, even after growth. Here, we identified hemodynamic features associated with aneurysmal rupture after growth. MATERIALS AND METHODS: We analyzed nine middle cerebral artery aneurysms that grew during the follow-up period using computational fluid dynamics analysis. Growth patterns of the middle cerebral artery aneurysms were divided into homothetic growth (Type 1), de novo bleb formation (Type 2), and bleb enlargement (Type 3). Hemodynamic parameters of the four ruptured aneurysms after growth were compared with those of the five unruptured aneurysms. RESULTS: Among nine aneurysms (78%), seven were Type 1, one was Type 2, and one was Type 3. Three (43%) Type 1 aneurysms ruptured after growth. Maximum oscillatory shear index after aneurysmal growth was significantly higher in ruptured Type 1 cases than in unruptured Type 1 cases (ruptured vs. unruptured: 0.455 ± 0.007 vs. 0.319 ± 0.042, p = 0.003). In Type 1 cases, a newly emerged high-oscillatory shear index area was frequently associated with rupture, indicating a rupture point. Aneurysm growth was observed in the direction of the high-pressure difference area before enlargement. In Types 2 and 3 aneurysms, the maximum oscillatory shear index decreased slightly, however, the pressure difference values remain unchanged. In Type 3 aneruysm, the maximum OSI and PD values remained unchanged. CONCLUSIONS: This study suggests that hemodynamic variations and growth pattern changes are crucial in rupture risk determination using computational fluid dynamics analysis. High-pressure difference areas may predict aneurysm enlargement direction. Additionally, high maximum oscillatory shear index values after enlargement in cases with homothetic growth patterns were potential rupture risk factors.

One-Stage Combined Open and Endovascular Treatment Using a Hybrid Operating Room is Safe and Effective for Distal Middle Cerebral Artery Aneurysms.

BACKGROUND: Aneurysms located in the distal middle cerebral artery (DMCA) are relatively rare and lack an established treatment strategy. For DMCA aneurysms, we performed a one-stage combined procedure of endovascular parent artery occlusion (PAO) with coils and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in a hybrid operating room (HOR). The aim of this study was to evaluate the safety and efficacy of this procedure. METHODS: Cases of unruptured DMCA aneurysms treated with the one-stage combined PAO and STA-MCA bypass in HOR were retrospectively examined, and patients' and aneurysmal backgrounds, surgical procedures, and treatment outcomes were analyzed. RESULTS: Six patients were included in the study. The average maximum diameter of the aneurysms was 14.4 mm. One aneurysm was located at M2 and five at M3. All aneurysms had a fusiform shape. No cases were associated with infection, trauma, or malignant tumors. In all 6 cases, the combined PAO and STA-MCA bypass was successfully completed. No postoperative hemorrhagic complications occurred. A symptomatic ischemic complication occurred in 1 case whose symptom disappeared in a week. Three months after surgery, complete obliteration of the aneurysm and patency of the bypass was confirmed in all cases. CONCLUSIONS: The one-stage combined PAO and STA-MCA bypass in the HOR is safe and effective for DMCA aneurysms, potentially serving as a treatment option for this complex aneurysm.

Impact of Morphological Factors on the Future Growth of Unruptured Posterior Communicating Artery Aneurysms.

BACKGROUND: No previous study has established the factors associated with intracranial aneurysm growth using imaging data obtained before the appearance of morphological changes. Therefore, we investigated the factors related to future aneurysm growth in posterior communicating artery (Pcom) aneurysms. METHODS: Using a longitudinal database of intracranial aneurysm cases, we reviewed the findings for consecutive patients with unruptured Pcom aneurysms admitted to our institute from 2012 to 2021. Magnetic resonance images obtained over time were used to evaluate aneurysm growth. Aneurysms showing growth over time (group G) and unchanged aneurysms (group U) were compared in terms of background data and morphological factors. RESULTS: 93 Pcom aneurysms (group G: 25 aneurysms, 25%; group U: 68 aneurysms, 75%) were eligible for the present study. Six aneurysm rupture events occurred in group G (24%). Among morphological factors, Pcom diameter (1.2 ± 0.3 mm vs. 0.8 ± 0.7 mm, P < 0.01), bleb formation (group G: 39% vs. group U: 10%; odds ratio, 5.6; P = 0.01), and the lateral projection of the dome (group G: 52% vs. group U: 13%; odds ratio, 3.2; P = 0.023) were significantly different between the 2 groups. The sensitivity and specificity of a cutoff Pcom diameter of 0.73 mm for predicting enlargement were 96% and 53%, respectively. CONCLUSIONS: Pcom diameter, bleb formation, and lateral dome projection were associated with growth of Pcom aneurysms. Aneurysms with these risk factors require careful follow-up imaging, which may facilitate early detection of aneurysm growth and prevention of rupture through therapeutic interventions.

A Case of Direct Carotid-Cavernous Fistulae Successfully Treated by Bidirectional Double Catheter Technique: A Technical Note.

Objective: Ruptured carotid-cavernous aneurysms (CCAs) are known to result in direct carotid-cavernous fistula (CCF). Although endovascular treatment is recognized as the first-line treatment for direct CCF, obliteration is sometimes difficult because of the high-flow shunt. In this report, we present a case of a direct CCF treated by the combination of transarterial and transvenous approaches. Case Presentation: A 57-year-old woman presented with conjunctival chemosis, exophthalmos, and tinnitus. Ophthalmological examination revealed increased intraocular pressure. DSA demonstrated a direct CCF due to a right ruptured CCA with retrograde shunted flow through the superior ophthalmic vein (SOV), superficial middle cerebral vein, basal vein of Rosenthal, and middle temporal vein. Two microcatheters were guided into the shunt segment from the internal carotid artery and SOV. In addition, a balloon catheter was placed at the neck of the aneurysm to assist coiling. Coil embolization for the CCF was performed using two microcatheters in the opposite direction, which enabled compact and tight packing of the shunt segment with only six coils. The CCF was eliminated. Two-year-follow-up MRA revealed no recurrence. Conclusion: The bidirectional double catheter technique is a useful approach to obliterate a shunt in a short segment with minimal coils.

Coiling for Ruptured Aneurysms in the Vasospasm Period: Safety and Efficacy Based on a Propensity Score Analysis.

Objective: To evaluate the efficacy and safety of interventional radiology (IVR) for aneurysmal subarachnoid hemorrhage (SAH) later than 3 days after onset. Methods: A total of 71 patients between 2012 and 2017 who underwent endovascular coiling were divided into two groups according to the timing of treatment: Group E (treated within 3 days after onset) and group D (treated between 4 and 14 days after onset), and the outcomes between two groups were compared. A case-matched study was conducted to minimize the selection bias lying in this cohort. Results: There were 56 (78.9%) and 15 (21.1%) patients in groups E and D, respectively. In group D, all patients arrived at the hospital later than 3 days after onset. The rates of patients with WFNS grade 1, 2, 3 and the presence of vasospasm upon the access route to the targeted aneurysm at the time of IVR were significantly higher in group D than in group E (93.3% vs 60.7%; p = 0.027, 33.3% vs 3.6%; p = 0.0037, respectively). There were no significant differences in the rate of intraprocedural complications, symptomatic vasospasm, delayed cerebral infarction due to vasospasm, retreatment, or modified Rankin Scale (mRS) at discharge. After propensity score matching, there were no significant differences in the outcomes between two groups. Conclusion: Prompt coiling for patients with ruptured aneurysms who arrived later than 3 days after onset can be safely performed, even if they had vasospasm upon the access route.

Aspect Ratio Is Associated with Recanalization after Coiling of Unruptured Intracranial Aneurysms.

The rate of recanalization after coil embolization for unruptured intracranial aneurysms (UIAs) is reported to occur around 11.3%-49%. This study aims to investigate the factors that influence the recanalization after coil embolization for UIAs in our institution. We retrospectively investigated 307 UIAs in 296 patients treated at our institution between April 2004 and December 2016. The stent-used cases were excluded. Cerebral angiography and 3D time-of-flight magnetic resonance angiography (TOF MRA) were used for evaluation of the postoperative occlusion status. Volume embolization ratio (VER), aneurysmal size, neck width, and aspect ratio (AR) were compared between the recanalized and non-recanalized groups. The mean follow-up period ranged from 6 to 172 months (mean: 79.0 ± 39.8 months). Recanalization was noted in 78 (25.4%) aneurysms, and 19 (6.2%) aneurysms required retreatment. There was no aneurysmal rupture during the follow-up period. Univariate analysis showed that the aneurysm size (p < 0.001), neck width (p < 0.001), AR (p = 0.003), and VER (p = 0.012) were associated with recanalization. Multivariate logistic regression analysis showed that the AR (p =0.004) and VER (p =0.015) were significant predictors of recanalization. To summarize, a higher AR and a lower VER could lead to recanalization after coil embolization of UIAs. Careful follow-up is required for coiled aneurysms with these features.