Intraorbital Dural Arteriovenous Fistula Treated by Transarterial Embolization Using Onyx: A Case Report.

Objective: Intraorbital dural arteriovenous fistula (IO-dAVF) is a rare condition, and treatment options vary from case to case. We report a case of transarterial embolization (TAE) for IO-dAVF. Case Presentation: A 62-year-old male complained of gradually worsening pain, hyperemia, and visual impairment in the right eye. He did not exhibit diplopia or exophthalmos. Cerebral angiography revealed an arteriovenous fistula in the right orbit. The feeding arteries were the ophthalmic artery (OphA) and the artery of the superior orbital fissure (ASOF), with the superior ophthalmic vein (SOV) as the main draining vein. The venous pathway from the SOV was not clearly visible, and considering the risk of blindness with TAE from the OphA, TAE from the ASOF was performed. Onyx 18 was selected as the liquid embolic material and injected through a microcatheter placed in the internal maxillary artery. Occlusion up to the SOV was achieved, and the shunt flow completely disappeared. Normal blood flow in the OphA was maintained, hyperemia improved, and no complications were observed. Conclusion: In cases of IO-dAVF, when transvenous embolization is difficult to perform, TAE using Onyx from the vessel of the external carotid artery system may be preferred over OphA.

Treatment Results of Carotid Artery Stenting with an Open-Cell Stent: Analysis of 734 Consecutive Cases at a Single Center.

OBJECTIVE: In carotid artery stenting (CAS) for internal carotid artery stenosis, the stent is often selected according to the plaque properties and arterial tortuosity. In our institute, an open-cell stent is used as the first-line stent regardless of the characteristics of the lesion. This study was performed to examine the outcome of CAS with an open-cell stent as the real-world results. METHODS: In total, 811 CAS procedures using open-cell stents were performed for internal carotid artery stenosis from April 2002 to December 2019. Of these patients, we excluded those with hyperacute conditions for which CAS was performed within 3 days of onset, those in whom acute mechanical thrombectomy was performed simultaneously with CAS, and those with stenosis due to arterial dissection. Thus, 734 patients were retrospectively analyzed. Perioperative and long-term outcomes and risk factors for perioperative infarction were investigated. RESULTS: The periprocedural stroke rate and mortality rate were 3.7% (27/734) and 0.4% (3/734), respectively. Low-echoic plaque was a significant risk factor for periprocedural stroke in both univariate (P < 0.03) and multivariate (odds ratio, 2.69; 95% confidence interval, 1.14-6.66; P = 0.02) analyses. Cerebral infarction and high grade restenosis were observed in 15 (2.0%) and 17 (2.3%) patients during a median 50-month follow-up. CONCLUSIONS: CAS with open-cell stents showed good results in terms of both the postoperative stroke incidence and long-term severe restenosis rate. However, low-echoic plaque was a risk factor for perioperative stroke incidence, which should be considered when deciding on the indication for CAS with an open-cell stent.

Novel use of a closed-tip stent retriever to prevent distal embolism in the posterior circulation: illustrative case.

BACKGROUND: In mechanical thrombectomy for tandem occlusions in vertebrobasilar stroke, distal emboli from the vertebral artery lesion should be prevented. However, no suitable embolic protection devices are currently available in the posterior circulation. Here, the authors describe the case of a vertebral artery lesion effectively treated with a closed-tip stent retriever as an embolic protection device in the posterior circulation. OBSERVATIONS: A 65-year-old male underwent mechanical thrombectomy for basilar artery occlusion, with tandem occlusion of the proximal vertebral artery. After basilar artery recanalization via the nonoccluded vertebral artery, a subsequent mechanical thrombectomy was performed for the occluded proximal vertebral artery. To prevent distal embolization of the basilar artery, an EmboTrap III stent retriever was deployed as an embolic protection device within the basilar artery to successfully capture the thrombus. LESSONS: A stent retriever with a closed-tip structure can effectively capture thrombi, making it a suitable distal embolic protection device in the posterior circulation.

Clinical evaluation of mechanical thrombectomy for patients with posterior circulation occlusion: A retrospective study.

OBJECTIVE: Although consensus has been reached regarding the use of mechanical thrombectomy for acute large anterior circulation occlusion, its effectiveness in patients with posterior circulation occlusion remains unclear. This study aimed to establish the determining factors for good clinical outcomes of mechanical thrombectomy for posterior circulation occlusion. METHODS: We extracted cases of acute large vessel occlusion (LVO) in the posterior circulation from a database comprising 536 patients who underwent mechanical thrombectomy at our hospital between April 2015 and March 2021. RESULTS: Fifty-two patients who underwent mechanical thrombectomy for LVO in the posterior circulation were identified. Five patients with simultaneous occlusion of the anterior and posterior circulation were excluded; finally, 47 patients were included in this study. The median patient age was 78 years, and 36% of the patients were women. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 31, the median posterior circulation-Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS) was 8, and the median Basilar Artery on Computed Tomography Angiography (BATMAN) score was 6. The rate of good recanalization (Thrombolysis in Cerebral Infarction scale grades 2b and 3) was 96%, and a good prognosis (modified Rankin Scale score of 0-2 at 90 days) was achieved in 19 patients (40%). The median pc-ASPECTS was significantly higher in the good prognosis group than in the poor prognosis group (10 vs. 7; p = 0.007). The median NIHSS score at presentation was significantly lower in the good prognosis group than in the poor prognosis group (17 vs. 34; p = 0.02). The median BATMAN score was significantly higher in the good prognosis group than in the poor prognosis group (8 vs. 3.5; p = 0.0002). Multivariate analysis showed that an NIHSS score ≦ 20 at presentation was the only independent factor for good prognoses. CONCLUSION: The prognosis of mechanical thrombectomy for posterior circulation LVO was better in patients with lower NIHSS scores at presentation.

Pipeline embolization device dynamics: prediction of incomplete occlusion by elongation from nominal length.

OBJECTIVE: According to benchtop studies, the oversizing of a Pipeline embolization device (PED) relative to the parent artery leads to a significant increase in porosity and potentially compromises aneurysm occlusion as well as transitional zone (TZ) formation around the neck of aneurysms. However, no clinical assessment has been reported. Here this potential was studied by measuring the dynamic changes of PEDs in the clinical time course. METHODS: The authors retrospectively examined 124 anterior circulation unruptured aneurysms in 114 consecutive patients treated with a PED between July 2015 and December 2020 at their institution. The authors excluded 77 cases of 68 patients with adjunctive coil embolization or multiple stents that could affect the PED dynamics and measurements, and 47 aneurysms in 46 patients were included. Measurements were performed before, immediately after, and 6 months after treatment, and then at intervals of 6 months to 1 year after that for nonocclusion cases. RESULTS: Complete occlusion was achieved in 79.0% and incomplete occlusion in 21.0% at last follow-up. The PED length immediately after deployment was 136% nominal length. A multivariable regression analysis revealed that age (OR 1.11/year; p = 0.02) and PED elongation from nominal length (OR 1.31/mm; p = 0.012) were independently associated with a higher rate of incomplete occlusion at the last follow-up. TZ formation did not affect the occlusion rate. CONCLUSIONS: PED elongation from the nominal length is a new predictor of incomplete aneurysm occlusion. The PED showed vascular remodeling by changing its diameter and length in the clinical course. TZ formation was remodeled and did not affect the occlusion rate.

Risk of Bone Wax Migration During Retrosigmoid Craniotomy for Microvascular Decompression: Case-Control Study.

BACKGROUND AND OBJECTIVES: Bone wax is a flexible hemostatic agent commonly used for surgery in the posterior cranial fossa to control bleeding from the mastoid emissary vein. A large amount of bone wax can migrate into the sigmoid sinus through the mastoid emissary canal (MEC). We aimed to identify clinical factors related to intraoperative bone wax migration through the MEC during microvascular decompression (MVD) surgery, which may result in sigmoid sinus thrombosis. METHODS: We retrospectively collected the clinical data of patients with trigeminal neuralgia, hemifacial spasm, or trigeminal neuralgia accompanied by painful tic convulsif who underwent MVD. Basic information and the residual width and length (from the bone surface to the sigmoid sinus) of the MEC on computed tomography images were collected. We compared the collected clinical data between 2 groups of cases with and without intraoperative bone wax migration in the sigmoid sinus. RESULTS: Fifty-four cases with intraoperative bone wax migration and 187 patients without migration were enrolled. The t -test revealed significant differences in the width and length of the MEC ( P = .013 and P = .003, respectively). These variables were identified as significant factors in predicting intraoperative bone wax migration using multivariate logistic regression analysis. CONCLUSION: The large size of the MEC may be related to intraoperative bone wax migration into the sigmoid sinus in MVD. Neurosurgeons should be aware of these risks. Bone wax should be applied appropriately and hemostasis should be considered to control bleeding from the mastoid emissary vein in patients with a large MEC.

Functionality and Usability of the Exoscope in Microvascular Decompression for Hemifacial Spasm and Trigeminal Neuralgia.

BACKGROUND: Studies on the functionality and usability of the exoscope in neurosurgical procedures against surgical microscopes (SMs) are limited. This study aimed to examine the functionality and usability of the exoscope during microvascular decompression (MVD) surgery. METHODS: Seven neurosurgeons evaluated the usefulness of a 4 K, 3-dimension digital exoscope in MVD by answering a questionnaire. The questionnaire inquired about the functionality and usability of the exoscope by utilizing a visual analog scale (VAS; 1-10). A score of 5 on VAS was equivalent to the corresponding quality of the SM. The learning effect of the exoscope was evaluated using mean VAS scores in the first and last 3 cases for each neurosurgeon. RESULTS: The functionality of the exoscope in MVD was superior to that in SM (P < 0.001). In the last 3 surgeries, the mean VAS scores of the exoscope were excellent in terms of ease of arm handling, exchange of surgical instruments, ease of surgical procedure, and intraoperative physical stress. The mean VAS scores of the exoscope in intraoperative asthenopia were significantly higher than those of the SM (P < 0.001). No statistical significance was found in operation time, discharge outcome, and 1-year post-surgery outcome between MVD performed using the exoscope and SM. CONCLUSIONS: Neurosurgeons may experience reduced stress levels during MVD when using the exoscope. As the outcome of MVD using the exoscope did not demonstrate a statistical difference compared with MVD using the SM, the exoscope may prove to be a useful tool for performing MVD.

Hepatocyte-specific damage in acute toxicity of sodium ferrous citrate: Presentation of a human autopsy case and experimental results in mice.

Acute iron overload is known to exert deleterious effects in the liver, but detailed pathology has yet to be documented. Here, we report pathological findings in an autopsy case of acute iron toxicity and validation of the findings in mouse experiments. In a 39-year-old woman who intentionally ingested a large amount of sodium ferrous citrate (equivalent to 7.5 g of iron), severe disturbance of consciousness and fulminant hepatic failure rapidly developed. Liver failure was refractory to treatment and the patient died on Day 13. Autopsy revealed almost complete loss of hepatocytes, while bile ducts were spared. To examine the detailed pathologic processes induced by excessive iron, mice were orally administered equivalent doses of ferrous citrate. Plasma aminotransferase levels markedly increased after 6 h, which was preceded by increased plasma iron levels. Hepatocytes were selectively damaged, with more prominent damage in the periportal area. Phosphorylated c-Jun was detected in hepatocyte nuclei after 3 h, which was followed by the appearance of γ-H2AX expression. Hepatocyte injury in mice was associated with the expression of Myc and p53 after 12 and 24 h, respectively. Even at lethal doses, the bile ducts were morphologically intact and fully viable. Our findings indicate that acute iron overload induces hepatocyte-specific liver injury, most likely through hydroxyl radical-mediated DNA damage and subsequent stress responses.

First-in-human trial of Center Wire for neuroendovascular therapy to avoid guidewire-related complications.

BACKGROUND: An exchange maneuver is useful for the delivery of devices to target vessels. However, hemorrhagic complications can occur due to vessel perforation during an exchange maneuver. In addition, the exchange is often challenging due to unfavorable anatomy. Center Wire is an exchange-length wire with a nondetachable stent that was developed to improve navigation and stability during exchange maneuvers. The aim of this study is to investigate the safety and efficacy of Center Wire of the anchor wire technique during neuroendovascular treatment. METHODS: Ten patients with intracranial aneurysms were treated after signing a Certified Review Board-approved consent. Anchor wire technique was used in all patients to navigate catheters to the target vessel for aneurysm treatment. RESULTS: Anchor wire technique was successfully applied in all 10 cases using Center Wire. One device-related incident of vasospasm occurred which was asymptomatic. No device-related dissection, perforation, or thromboembolic events occurred. One patient had intraoperative aneurysm rupture during coil placement which was treated immediately without clinical consequences. Two patients had postoperative ischemic strokes due to thrombotic occlusion of branches originating from the aneurysm which were unrelated to the device. CONCLUSIONS: This first-in-human trial of Center Wire demonstrated the safety and efficacy of the anchor wire technique for neuroendovascular treatment in a strictly regulated prospective registry trial.

Detection of CpG methylation level using methyl-CpG-binding domain-fused fluorescent protein.

Methylation of cytosine to 5-methylcytosine on CpG dinucleotides is the most frequently studied epigenetic modification involved in the regulation of gene expression. In normal tissues, tissue-specific CpG methylation patterns are established during development. In contrast, alterations in methylation patterns have been observed in abnormal cells, such as cancer cells. Cancer type-specific CpG methylation patterns have been identified and used as biomarkers for cancer diagnosis. In this study, we developed a hybridization-based CpG methylation level sensing system using a methyl-CpG-binding domain (MBD)-fused fluorescent protein. In this system, the target DNA is captured by a complementary methylated probe DNA. When the target DNA is methylated, a symmetrically methylated CpG is formed in the double-stranded DNA. MBD specifically recognizes symmetrical methyl-CpG on double-stranded DNA; therefore, the methylation level is quantified by measuring the fluorescence intensity of the bound MBD-fused fluorescent protein. We prepared MBD-fused AcGFP1 and quantified the CpG methylation levels of the target DNA against SEPT9, BRCA1, and long interspersed nuclear element-1 (LINE-1) using MBD-AcGFP1. This detection principle can be applied to the simultaneous and genome-wide modified base detection systems using microarrays coupled with modified base binding proteins fused to fluorescent proteins.

Intramedullary feeder aneurysm of a cervical epidural arteriovenous fistula causing myelopathy: a case report and literature review.

While a craniocervical junction (CCJ) epidural arteriovenous fistula (EDAVF) may present with hemorrhagic myelopathy from an associated feeder aneurysm on rare occasions, non-hemorrhagic myelopathy from such an aneurysm remains unreported. A woman in her late sixties presented with cervical myelopathy due to a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF. The intramedullary aneurysm originated from the spinal pial artery supplied by the anterior spinal artery. Direct surgical fistula coagulation and feeder obliteration resulted in the disappearance of the aneurysm and myelopathy improvement. This report illustrates the first case of a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF successfully treated with direct surgery.

First-in-human trial of Stabilizer device in neuroendovascular therapy.

Objectives: Flow diverter or stent implantation to intracranial target lesion requires large inner diameter microcatheter navigation. The exchange method using stiff long wire is often necessary if it is difficult to navigate over the regular guidewire. However, this method has an intrinsic risk of vessel damage and may cause severe complications. We investigated the safety and efficacy of a new device, the Stabilizer device for navigation in a first-in-human clinical trial under the Certified Review Board agreement. Materials and methods: The Stabilizer is a 320 cm length exchange wire with a stent for anchoring and is compatible with a 0.0165" microcatheter. The trial design is a prospective single-arm open-label registry. Inclusion criteria are elective flow diverter treatment or stent-assisted coiling, expected to be difficult to navigate a microcatheter with a regular micro guidewire, and obtained documented consent. The primary endpoint of the study was a hemorrhagic complication. Results: Five patients were enrolled in this trial. The median age is 52 years, ranges from 41 to 70, and all patients were female. Three aneurysms were located on the internal carotid artery, one on the vertebral artery, and one on the basilar artery. Basilar artery aneurysm was treated by stent-assisted coiling and others were treated by flow diverter deployment. All cases successfully navigate microcatheter for the treatment by the trial method using Stabilizer device without any adverse event. Conclusions: The results from this first-in-human consecutive five cases show the safety of the Stabilizer device in neuro-endovascular therapy for navigation of devices to the intracranial target lesion.

High levels of Myc expression are required for the robust proliferation of hepatocytes, but not for the sustained weak proliferation.

In contrast to the robust proliferation exhibited following acute liver injury, hepatocytes exhibit long-lasting proliferative activity in chronic liver injury. The mechanistic differences between these distinct modes of proliferation are unclear. Hepatocytes exhibited robust proliferation that peaked at 2 days following partial hepatectomy in mice, but this proliferation was completely inhibited by hepatocyte-specific expression of MadMyc, a Myc-suppressing chimeric protein. However, Myc suppression induced weak but continuous hepatocyte proliferation, thereby resulting in full restoration of liver mass despite an initial delay. Late-occurring proliferation was accompanied by prolonged suppression of proline dehydrogenase (PRODH) expression, and forced PRODH overexpression inhibited hepatocyte proliferation. In hepatocytes in chronic liver injury, Myc was not activated but PRODH expression was suppressed in regenerating hepatocytes. In liver tumors, PRODH expression was often suppressed, especially in the highly proliferative tumors with distinct Myc expression. Our results indicate that the robust proliferation of hepatocytes following acute liver injury requires high levels Myc expression and that there is a compensatory Myc-independent mode of hepatocyte proliferation with the regulation of proline metabolism, which might be relevant to liver regeneration in chronic injury.

PulseRider-assisted coil embolization for an unruptured internal carotid artery-persistent primitive trigeminal artery aneurysm.

A persistent primitive trigeminal artery (PPTA) is a vessel remnant of carotid-vertebrobasilar anastomosis. The aneurysm at the bifurcation of the internal carotid artery (ICA) and PPTA tends to have a broad neck with the branch incorporated into the sac. Because PPTA supplies to the posterior circulation and branches off direct pontine perforators, PPTA preservation should always be considered when treating PPTA aneurysms to avoid ischemic complications.We report a case of the wide-neck ICA-PPTA aneurysm successfully treated with the PulseRider-assisted coil embolization, resulting in complete occlusion with PPTA patency. Relevant anatomy and endovascular strategy of the PPTA aneurysms are discussed.

Predicting the growth of middle cerebral artery bifurcation aneurysms using differences in the bifurcation angle and inflow coefficient.

OBJECTIVE: Growing intracranial aneurysms (IAs) are prone to rupture. Previous cross-sectional studies using postrupture morphology have shown the morphological or hemodynamic features related to IA rupture. Yet, which morphological or hemodynamic differences of the prerupture status can predict the growth and rupture of smaller IAs remains unknown. The purpose of this longitudinal study was to investigate the effects of morphological features and the hemodynamic environment on the growth of IAs at middle cerebral artery (MCA) bifurcations during the follow-up period. METHODS: One hundred two patients with MCA M1-2 bifurcation saccular IAs who underwent follow-up for more than 2 years at the authors' institutions between 2011 and 2019 were retrospectively identified. During the follow-up period, cases involving growth of MCA IAs were assigned to the event group, and those with MCA IAs unchanged in size were assigned to the control group. The morphological parameters examined were aneurysmal neck length, dome height, aspect ratio and volume, M1 and M2 diameters and their ratio, and angle configurations among M1, M2, and the aneurysm. Hemodynamic parameters were flow rate and wall shear stress in M1, M2, and the aneurysm, including the aneurysmal inflow rate coefficient (AIRC), defined as the ratio of the aneurysmal inflow rate to the M1 flow rate. Those parameters were compared statistically between the two groups. Correlations between morphological and hemodynamic parameters were also examined. RESULTS: Eighty-three of 102 patients were included: 25 with growing MCA IAs (event group) and 58 with stable MCA IAs (control group). The median patient age at initial diagnosis was 66.9 (IQR 59.8-72.3) years. The median follow-up period was 48.5 (IQR 36.5-65.6) months. Both patient age and the AIRC were significant independent predictors of the growth of MCA IAs. Moreover, the AIRC was strongly correlated with sharper bifurcation and inflow angles, as well as wider inclination angles between the M1 and M2 arteries. CONCLUSIONS: The AIRC was a significant independent predictor of the growth of MCA IAs. Sharper bifurcation and inflow angles and wider inclination angles between the M1 and M2 arteries were correlated with the AIRC. MCA IAs with such a bifurcation configuration are more prone to grow and rupture.

Cone-beam CT-assisted microcatheter tip placement at the shunted pouch entry zone: A technical note for anterior condylar arteriovenous fistula.

Accurate microcatheter placement for anterior condylar arteriovenous fistula (AVF) enables selective transvenous embolization (TVE) and helps to avoid hypoglossal nerve palsy. Anterior condylar AVF has a shunted pouch within the condylar vascular and osseous structures. Detailed anatomical comprehension of the shunted pouch is essential, in addition, we believe that it is important to have a strategy for where in the shunted pouch to start filling with coils. Specifically, we consider that it is important to structurally understand the more upstream location (arterial side) within the shunted pouch (called "shunted pouch entry zone"), guide the microcatheter there, and embolize from that site. Although several studies have discussed the usefulness of intraoperative cone-beam computed tomography (CBCT) for treating anterior condylar AVF, there are no studies which have mentioned the importance of microcatheter position before coil embolization in selective TVE as in this study. Intraoperative localization of the shunted pouch entry zone is often difficult. Herein, the authors report that cone-beam computed tomography (CBCT) can assist accurate microcatheter tip placement at the shunted pouch entry zone before staring embolization. This is the novel application of intraoperative CBCT to treat anterior condylar AVF successfully treated with precise and selective TVE.

Quantitative detection of CpG methylation level on G-quadruplex and i-motif-forming DNA by recombinase polymerase amplification.

Detection of CpG methylation levels holds immense potential for application in medical diagnosis of various diseases. In this study, we report the development of a recombinase polymerase amplification (RPA)-based CpG methylation level sensing system on G-quadruplex (G4) and intercalated motif (i-motif)-forming regions, which are stabilized by CpG methylation. This detection system is based on the principle that DNA polymerase is stalled at the methylated G4 and i-motif-forming region, which results in a decrease in the initial elongation efficiency of RPA. This reduction in turn affects the onset of amplification depending on the extent of CpG methylation; therefore, the methylation level is quantified by RPA. We demonstrate that the onset of amplification was delayed by CpG methylation when PCR products containing the vascular endothelial growth factor (VEGF) G4 and i-motif-forming region were used as the template. Furthermore, onset of amplification was delayed with the increase in CpG methylation of the VEGF region on genomic DNA. These results demonstrate that the sensing system is capable of directly detecting the methylation level at a constant temperature (39 °C) within 30 min without performing bisulfite conversion or affinity capture of methylated DNA.

Infratentorial developmental venous anomaly concurrent with a cavernoma and dural arteriovenous fistula.

OBJECTIVES: While developmental venous anomaly (DVA) may be associated with cavernous malformation, mixed vascular malformation associated with dural arteriovenous fistula (dAVF) has not been previously reported. We observed a case with rare association of infratentorial DVA, cavernous malformation, and dAVF that presented with cerebellar ataxia. We report our endovascular treatment for this complex cerebrovascular condition. CASE PRESENTATION: A 32-year-old woman with ataxia had an infratentorial DVA associated with a cavernoma and dAVF. The dAVF had two shunting points. The dAVF was fed by the posterior meningeal arteries and drained through the sigmoid sinus into the transverse sinus. The dAVF was also fed by the occipital artery and retrogradely drained through the left jugular bulb into the dilated collecting vein of the DVA. Endovascular embolization was performed for the dAVF and dilated collecting vein of the DVA. Postoperative complications did not occur after embolization with no recurrence for three years. CONCLUSIONS: This is the first reported case of infratentorial DVA associated with a cavernoma and dAVF. Endovascular treatment was effective in treating this symptomatic complex cerebrovascular disorder.

The bifurcation angle is associated with the progression of saccular aneurysms.

The role of the bifurcation angle in progression of saccular intracranial aneurysms (sIAs) has been undetermined. We, therefore, assessed the association of bifurcation angles with aneurysm progression using a bifurcation-type aneurysm model in rats and anterior communicating artery aneurysms in a multicenter case-control study. Aneurysm progression was defined as growth by ≥ 1 mm or rupture during observation, and controls as progression-free for 30 days in rats and ≥ 36 months in humans. In the rat model, baseline bifurcation angles were significantly wider in progressive aneurysms than in stable ones. In the case-control study, 27 and 65 patients were enrolled in the progression and control groups. Inter-observer agreement for the presence or absence of the growth was excellent (κ coefficient, 0.82; 95% CI, 0.61-1.0). Multivariate logistic regression analysis showed that wider baseline bifurcation angles were significantly associated with subsequent progressions. The odds ratio for the progression of the second (145°-179°) or third (180°-274°) tertiles compared to the first tertile (46°-143°) were 5.5 (95% CI, 1.3-35). Besides, the bifurcation angle was positively correlated with the size of aneurysms (Spearman's rho, 0.39; P = 0.00014). The present study suggests the usefulness of the bifurcation angle for predicting the progression of sIAs.