The Potential Role of Preoperative Posterior Cerebral Artery Involvement in Predicting Postoperative Transient Neurological Deficits and Ischemic Stroke After Indirect Revascularization in Patients With Moyamoya Disease.

OBJECTIVE: Transient neurological deficits (TNDs) are known to develop after direct bypass for Moyamoya disease and may be risk factors for subsequent stroke. However, the factors involved in the development of TNDs and stroke after indirect revascularization alone, including their association with subsequent stroke, remain unclear. The purpose of this study was to investigate this issue. METHODS: The subjects of the study were 30 patients with Moyamoya disease who underwent a total of 40 indirect revascularization procedures at our institution. Clinical and radiological data were collected retrospectively. To examine factors associated with the development of postoperative TND/stroke/asymptomatic disease, the clinical characteristics of each group were statistically compared. RESULTS: The mean age at surgery was 7 years (range 1-63). TNDs developed after surgery in 9 out of 40 patients (22.5%). Stroke in the acute postoperative period occurred in 3 patients (7.5%), all of whom experienced cerebral infarctions. Demographic data and preoperative clinical information were not different between the groups. However, posterior cerebral artery involvement on preoperative imaging was significantly associated with the development of TNDs and stroke (P = 0.006). Furthermore, postoperative stroke was associated with unfavorable outcomes (P = 0.025). CONCLUSIONS: Posterior cerebral artery involvement is significantly associated with the occurrence of TNDs. In contrast, TNDs after indirect revascularization have little relationship with the subsequent development of stroke. TNDs usually resolve without new strokes, and a better understanding of this particular pathology could help establish an optimal treatment regimen.

Hormone Concentration Measurement in Intracranial Dural Arteriovenous Fistulae.

OBJECTIVE: Intracranial dural arteriovenous fistulae (DAVFs) represent a subset of cerebral vascular malformations associated with significant morbidity and mortality. In Japan, DAVF exhibits sex-based differences in anatomical distribution, with female predominance in the cavernous sinus (CS) and male predominance in the transverse sinus (TS). Nevertheless, the pathophysiology of DAVF is not fully understood, and hormonal influences are hypothesized to play a role in its development. This study aimed to investigate changes in the concentrations of sex steroid hormones between intracranial and peripheral sampling sites in patients with CS- and TS-DAVF. METHODS: We recruited 19 patients with CS-DAVF (n = 12) and TS-DAVF (n = 7) in this study. Blood hormone measurements were obtained from peripheral and jugular bulb samples during endovascular intervention. Hormone concentrations were analyzed using enzyme-linked immunosorbent assay kits, and statistical analyses were performed. RESULTS: Our study revealed a higher prevalence of CS-DAVF in females and TS-DAVF in males, which is consistent with previous studies. Estradiol concentration was significantly lower in the jugular bulb compared with in the periphery in both patients with CS- and TS-DAVF. This decrease in estradiol was observed irrespective of the patient's sex and independent of follicle-stimulating hormone levels. CONCLUSIONS: These findings indicate a local decrease in estradiol levels within the intracranial vasculature of patients with DAVF. This suggests a potential multifactorial role of estradiol in the pathomechanism of DAVFs, warranting further investigation to understand its influence on DAVF formation and potential targeted therapies, thereby enhancing patient outcomes.

Efficacy of intraoperative irrigation with artificial cerebrospinal fluid in chronic subdural hematoma surgery: study protocol for a multicenter randomized controlled trial.

BACKGROUND: The surgical techniques for treatment of chronic subdural hematoma (CSDH), a common neurosurgical condition, have been discussed in a lot of clinical literature. However, the recurrence proportion after CSDH surgery remains high, ranging from 10 to 20%. The standard surgical procedure for CSDH involves a craniostomy to evacuate the hematoma, but irrigating the hematoma cavity during the procedure is debatable. The authors hypothesized that the choice of irrigation fluid might be a key factor affecting the outcomes of surgery. This multicenter randomized controlled trial aims to investigate whether intraoperative irrigation using artificial cerebrospinal fluid (ACF) followed by the placement of a subdural drain would yield superior results compared to the placement of a subdural drain alone for CSDH. METHODS: The study will be conducted across 19 neurosurgical departments in Japan. The 1186 eligible patients will be randomly allocated to two groups: irrigation using ACF or not. In either group, a subdural drain is to be placed for at least 12 h postoperatively. Similar to what was done in previous studies, we set the proportion of patients that meet the criteria for ipsilateral reoperation at 7% in the irrigation group and 12% in the non-irrigation group. The primary endpoint is the proportion of patients who meet the criteria for ipsilateral reoperation within 6 months of surgery (clinical worsening of symptoms and increased hematoma on imaging compared with the postoperative state). The secondary endpoints are the proportion of reoperations within 6 months, the proportion being stratified by preoperative hematoma architecture by computed tomography (CT) scan, neurological symptoms, patient condition, mortality at 6 months, complications associated with surgery, length of hospital stay from surgery to discharge, and time of the surgical procedure. DISCUSSION: We present the study protocol for a multicenter randomized controlled trial to investigate our hypothesis that intraoperative irrigation with ACF reduces the recurrence proportion after the removal of chronic subdural hematomas compared with no irrigation. TRIAL REGISTRATION: ClinicalTrials.gov jRCT1041220124. Registered on January 13, 2023.

Characteristics of donor vessels and cerebral blood flow in the chronic phase after combined revascularization surgery for moyamoya disease.

OBJECTIVE: This study aimed to analyze whether the development of donor vessels after combined revascularization surgery for moyamoya disease (MMD) is related to cerebral blood flow (CBF) changes. METHODS: We retrospectively reviewed the charts of 11 adult (12 hemispheres) and 13 pediatric (19 hemispheres) patients who underwent combined revascularization in our department. The total vessel cross-sectional area (TVA) was the sum of the cross-sectional areas of the superficial temporal, middle meningeal, and deep temporal arteries imaged using time-of-flight magnetic resonance angiography. The ipsilateral relative CBF (RCBF) on the brain surface in the craniotomy area was calculated by single-photon emission computed tomography. ΔTVA and ΔRCBF were defined as the preoperative and postoperative ratios of TVA and RCBF, and their correlations were analyzed in adult and pediatric patients. RESULTS: The TVA and RCBF showed a significant increase after surgery, regardless of the age group. However, there was no significant correlation between ΔTVA and ΔRCBF in either the adult or pediatric groups. While the adult group exhibited significantly higher ΔRCBF values compared to the pediatric group (p < 0.01, r = -0.44), the ΔTVA values were higher in the pediatric group compared to the adult group (p = 0.06). CONCLUSIONS: In the chronic phase after combined revascularization surgery for MMD, the development of measurable TVA of donor vessels does not necessarily correlate with an increase in CBF around the craniotomy area.

Effect of thin-split encephalomyosynangiosis on transient neurological events in revascularization surgery for pediatric patients with moyamoya disease.

OBJECTIVE: Transient neurological events (TNEs) are among the most important events after revascularization surgery in pediatric patients with moyamoya disease (MMD). Although hemodynamic changes and crying are representative factors of TNEs, brain compression by encephalomyosynangiosis (EMS) is another important cause of TNEs. Therefore, the authors assumed that making the EMS as thin as possible reduces the frequency of TNEs. However, thin-split EMS can lead to insufficient development of collateral vessels. This study aimed to evaluate the effects of thin-split EMS in combined revascularization surgery on postoperative outcomes in pediatric patients with MMD. METHODS: The authors retrospectively included 56 consecutive combined revascularization surgeries in the anterior cerebral circulation in pediatric patients with MMD. These surgeries were classified into the former group and thin-split EMS group. The temporal muscle was halved in the former EMS group and split as thinly as possible in the thin-split EMS group. The authors performed between-group comparisons of postoperative stroke events and TNEs during the acute period and the development of collateral flow and stroke events during the chronic period. RESULTS: Former and thin-split EMS procedures were performed in 37 and 19 patients, respectively. TNEs without crying or hemodynamic changes were observed significantly less frequently in the thin-split EMS group than in the former EMS group (0 [0.0%] in the thin-split EMS group vs 9 [24.3%] in the former EMS group, p = 0.021). There were no significant between-group differences in the development of indirect bypass during the chronic period (good: 34 [91.9%] and poor: 3 [8.1%] in the former EMS group vs good: 16 [84.2%] and poor: 3 [15.8%] in the thin-split EMS group; p = 0.397). Additionally, there were no significant between-group differences in the incidence of chronic clinical events, including death or stroke. CONCLUSIONS: Thin-split EMS can reduce TNEs that do not accompany crying or hemodynamic changes. Furthermore, the procedure has sufficient prevention effects against stroke events during the chronic postoperative period in pediatric patients with MMD.

Usefulness of Stanch Belt Plus in Postoperative Management after Endovascular Neurosurgery.

Objective: We verified the usefulness of patient management using a balloon-pressurized belt (Stanch Belt Plus) to prevent puncture site hematomas, which can occur at a specific rate even with hemostatic devices after endovascular neurosurgery. Methods: A total of 113 patients who underwent endovascular surgery with a femoral puncture from April 2019 to September 2020 were divided into two groups: 31 cases using a traditional compression belt and 82 cases using a newly introduced balloon-pressurized belt during this period. The clinical data were analyzed retrospectively. The chi-square test and Mann-Whitney U test were used to test for significant differences. Results: There were no significant differences in treatment procedures or frequency of hemostatic device use, but the balloon-pressurized belt group had a significantly lower incidence of hematomas (2.4% vs 12.9%, p <0.05) and a significantly lower incidence of moderate or higher lumbago (22.0% vs 41.9%, p <0.05). The incidence of epidermal detachment tended to be low; however, no significant difference was observed (3.7% vs. 12.9%, n.s.). Conclusion: Patient management with the newly introduced balloon-pressurized belt may decrease the occurrence of groin hematoma and lumbago among complications after endovascular neurosurgery.

Difference of coil distribution made by finishing coils in large size aneurysm model with radiolucent coils.

We conducted a study to understand the characteristics of the finishing coils to select the appropriate coil for the final stage of embolization. Consequently, experimental embolization was performed on a 10 mm spherical silicone aneurysm filled with radiolucent coils, which simulated a volume embolization ratio of 20%. Nine different coils (i-ED complex ∞ SilkySoft, SilkySoft, ExtraSoft, V-Trak HyperSoft helical, Barricade 10 complex finishing, Optima complex 10 soft, Target 360 Ultra, Galaxy G3 mini, and Axium prime 3D ExtraSoft) were analyzed six times at random. After each coil insertion, indices that include area, Feret diameter, circularity, and centroid center of mass were calculated using biplane x-ray images. Furthermore, these data were analyzed using the spring constant k, which represents the stiffness of the coil. In multiple comparisons, a significant difference was observed in the area analysis. The i-ED complex ∞ SilkySoft was more widespread than Target 360 Ultra (p < 0.05). However, no significant differences were observed in the other indices. The spring constant k value of Target 360 Ultra was 2.5 times larger than that of the i-ED complex ∞ SilkySoft, and it negatively correlated with the area index rather than with the other indices. Notably, it was suggested that the smaller the spring constant k, the wider the distribution of the finishing coils. Although there was little difference between the coils, some coils had characteristics suggesting that good embolization could be expected using appropriate finishing coils.

A Case of Bilateral Vertebral Artery Dissecting Aneurysm Treated With Multimodality Therapy Under Superficial Temporal Artery Assistance-Posterior Cerebral Artery Bypass.

A ruptured bilateral vertebral artery dissecting aneurysm (BVDA) is a challenging vascular disorder. Trapping surgery with bypass assistance could be a potential treatment; however, there is a risk of ischemic complications. Recently, endovascular treatment has been reported, but its long-term outcomes remain uncertain. The patient was a 57-year-old male who presented with subarachnoid hemorrhage. Digital subtraction angiography showed a dilated dominant left vertebral artery (VA) and a narrowed right VA, suggesting a BVDA. First, we performed a right superficial temporal artery-superior cerebellar artery (STA-SCA) insurance bypass. We then performed proximal clipping of the left vertebral VA. The pulsation of the STA-SCA bypass disappeared on day 6. Three-dimensional computed tomography angiography (3DCTA) showed the emergence of a fusiform aneurysm and proximal stenosis of the contralateral VA. On day 31, we performed a superficial temporal artery-posterior cerebral artery (STA-PCA) insurance bypass. Stent-assisted coil embolization was planned for two days after the STA-PCA bypass. However, preoperative angiography showed progression of right proximal VA stenosis, and stenting appeared impossible. There was no change in somatosensory evoked potential (SEP), and angiography showed sufficient retrograde blood flow to the posterior circulation during the right VA balloon occlusion test (BOT). Therefore, internal trapping of the right VA was performed. Postoperative angiography showed perfect patency of the left STA-PCA bypass and retrograde blood flow to the posterior circulation. There was no additional neurological deficit after endovascular treatment. Multimodality therapy could be a potential treatment for bilateral VA dissection.

Higher abundance of Campylobacter in the oral microbiome of Japanese patients with moyamoya disease.

Genetic factors alone cannot explain the pathophysiology of moyamoya disease (MMD), and environmental factors such as an immune response are thought to be involved. Oral and gut microbiomes have attracted attention as environmental factors in the pathophysiology of some vascular and autoimmune diseases. However, the relationship between MMD and these microbiomes is yet to be thoroughly investigated. This prospective case-control study aimed to compare the microbiomes of Japanese patients with MMD with those of healthy individuals to identify the specific bacteria involved in MMD. Saliva and fecal samples were collected from 16 patients with MMD who had not undergone revascularization surgery. Fifteen healthy individuals were matched for age, sex, and body mass index. The microbiomes were determined using 16S rRNA sequencing and analyzed using QIIME2. Differentially abundant microbes were identified using LEfSE and ANCOM-BC. In the oral microbiome, the two analytical methods showed that Campylobacter was more abundant in patients with MMD than in healthy individuals. Differences in the gut microbiome were smaller than those in the oral microbiome. In conclusion, the oral microbiome profiles of patients with MMD significantly differ from those of healthy individuals. Campylobacter spp. could be a substantial environmental factor in the pathophysiology of MMD.

Sacral arteriovenous fistula with lower thoracic cord edema without perimedullary vein enlargement.

Background: Sacral dural arteriovenous fistulas (AVFs) are often undiagnosed at the initial presentation due to their rarity. Case Description: For 1 year, a 71-year-old man developed progressive motor and sensory disturbances in both legs. Magnetic resonance imaging showed spinal cord edema with mild contrast enhancement at the T9-10 and T12 levels. Although mild venous dilatation was observed only at the cauda equina level, it was not initially recognized as abnormal. Blood and cerebrospinal fluid tests and spinal angiography of the lower thoracic to upper lumbar levels were nonspecific. The patient was unsuccessfully treated with three courses of high-dose intravenous methylprednisolone. Ultimately, following repeat spinal angiography (i.e., including the bilateral internal iliac arteries) that revealed a low-flow sacral dural AVF supplied by the right lateral sacral artery, the patient underwent successful surgical venous AVF occlusion/transection. Conclusion: In cases of spinal cord edema without perimedullary abnormal flow voids, careful spinal angiography including the sacral spine is necessary even if only minimal venous dilation is initially observed at the cauda equina level.

Transarterial embolization and transvenous embolization for transverse-sigmoid sinus dural arteriovenous fistulas with cortical venous reflux: A comparative study.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) with cortical venous reflux (CVR) carry a high risk for neurological sequelae or death. Recently, transverse-sigmoid sinus DAVFs were shown as good indications for transarterial embolization (TAE) with ONYX. Here, we compared the effectiveness and safety of conventional transvenous embolization (TVE) with those of TAE with ONYX for transverse-sigmoid sinus DAVFs with CVR. METHODS: Sixty-one patients with transverse-sigmoid sinus DAVFs were treated from April 2013 to May 2020. Among them, 37 patients with CVR were included. Transarterial embolization and TVE were compared in terms of complete occlusion and residual CVR immediately after treatment, complications with worsening modified Rankin Scale (mRS) ≥ 1, amount of contrast media used during treatment, radiation exposure, and surgical procedure time. RESULTS: Ten patients were treated with 10 TAEs using ONYX and 27 patients with 29 TVEs. Transarterial embolization and TVE showed no differences in the overall complete occlusion rate (80% [8/10 patients] vs. 80% [23/27], respectively), whereas the residual rate of existing CVR was 10% (1/10 patient) vs. 3.4% (1/27) in the TAE and TVE groups, respectively. No complications with worsening mRS ≥1 occurred in either group. Among the parameters of amount of contrast media, radiation dose, and operative time, only radiation dose in the TAE group was lower than that in the TVE group (median: 2239 mGy vs. 3268 mGy, respectively; p = 0.07). CONCLUSION: For transverse-sigmoid sinus DAVFs with CVR, TAE treatment reduced radiation exposure. However, both TAE and TVE achieved high complete occlusion rates and low complication rates.

Simultaneous Aneurysmal Subarachnoid Hemorrhage and Epistaxis in an Untreated Prolactinoma: A Case Report and Literature Review.

A 61-year-old man presented with massive epistaxis, amaurosis, nausea, and severe headache. A detailed examination revealed a subarachnoid hemorrhage and prolactinoma. Angiography showed a small internal carotid artery pseudoaneurysm and inadequate collateral circulation; thus, uncomplicated coil embolization was performed. Considering the side effects of medication, such as cerebrospinal fluid rhinorrhea, the patient was followed up for asymptomatic prolactinoma without medication after discharge. At 40 months later, aneurysm recurrence was confirmed. Flow diverter device placement was performed, and the outcomes were excellent. In the present report, we described a rare case of a ruptured internal carotid artery aneurysm in an untreated prolactinoma and discussed the literature.

Clinical Efficiency of an Artificial Intelligence-Based 3D-Angiography for Visualization of Cerebral Aneurysm: Comparison with the Conventional Method.

PURPOSE: Artificial intelligence (AI)-based three-dimensional angiography (3D-A) was reported to demonstrate visualization of cerebral vasculature equivalent to that of three-dimensional digital subtraction angiography (3D-DSA). However, the applicability and efficacy of the AI-based 3D­A algorithm have not yet been investigated for 3D-DSA micro imaging. In this study, we evaluated the usefulness of the AI-based 3D­A in 3D-DSA micro imaging. MATERIALS AND METHODS: The 3D-DSA micro datasets of 20 consecutive patients with cerebral aneurysm (CA) were reconstructed with 3D-DSA and 3D­A. Three reviewers compared 3D-DSA and 3D­A in terms of qualitative parameters (degrees of visualization of CA and the anterior choroidal artery [AChA]) and quantitative parameters (aneurysm diameter, neck diameter, parent vessel diameter, and visible length of AChA). RESULTS: Qualitative evaluation of diagnostic potential revealed that visualization of CA and the proximal to middle parts of the AChA with 3D­A was equal to that with conventional 3D-DSA; in contrast, visualization of the distal part of the AChA was lower with 3D­A than with 3D-DSA. Further, regarding quantitative evaluation, the aneurysm diameter, neck diameter, and parent vessel diameter were comparable between 3D­A and 3D-DSA; in contrast, the visible length of the AChA was lower with 3D­A than with 3D-DSA. CONCLUSIONS: The AI-based 3D­A technique is feasible and evaluable visualization of cerebral vasculature with respect to quantitative and qualitative parameters in 3D-DSA micro imaging. However, the 3D­A technique offers lower visualization of such as the distal portion of the AChA than 3D-DSA.

Ruptured Middle Cerebral Artery Aneurysm in an Infant: Case Report and Literature Review.

Intracranial aneurysms (IA) in infants are reportedly rare at 0.5% to 4.5% of all aneurysms. Furthermore, subarachnoid hemorrhage in infants younger than three months are even rarer as it has been reported in approximately 20 cases only till date. A 3-month-old infant with seizures and impaired consciousness was admitted to our hospital. Three-dimensional computed tomography angiography (3D-CTA) revealed a dissecting aneurysm with a maximum diameter of 13 mm in the right M2. Internal trapping using detachable coil were successfully performed, following which he was discharged without significant neurological deficit after one month of onset. Thus, we have reported a rare case of a large ruptured dissecting IA in a 3-month-old infant, in the right middle cerebral artery (MCA), successfully treated with an endovascular therapy, along with a literature review.

Rare Dilated Collateral Circulation from Accessory Meningeal Artery to Inferolateral Trunk: A Case Report.

The accessory meningeal artery (AMA) demonstrates various potential anastomoses with the external (ECA) and internal (ICA) carotid arteries. However, rarely does the AMA markedly dilate and compensate for ICA blood flow. A 52-year-old woman with nonspecific symptoms was diagnosed with multiple cerebral aneurysms and abnormal blood vessels observed on magnetic resonance angiography. Digital subtraction angiography revealed four aneurysms and anastomoses between the left AMA and inferolateral trunk (ILT). In addition, two sequential severe flexions were observed in the cervical portion of the left ICA. No ischemic lesions were detected on magnetic resonance imaging. In conclusion, we experienced a rare case in which the AMA-ILT anastomosis was highly developed. This case also presented with the unusual characteristics of an anomaly in the extracranial ICA and multiple aneurysms.

Differences in gaze behaviors between trainees and experts during endovascular therapy for cerebral aneurysms: a preliminary study using a cerebral aneurysm model.

In the neuroendovascular field, the training of operators has become an important issue. Recently, eye-tracking technology has been introduced into various fields of medical education. This study aimed to apply eye-tracking technology to the training of neuroendovascular therapy. Six neurosurgeons, including three neuroendovascular specialists and three trainees, at our institution and related facilities participated in the study. Eye movement was recorded by the eye-tracking device during the microcatheter navigation and coil placement into the silastic aneurysm model under biplane X-ray fluoroscopy. Eye-tracking analysis during neuroendovascular therapy was feasible in all six subjects. In microcatheter navigation, specialists tended to more frequently switch their attention between frontal and lateral images than trainees. In coil embolization, the overall gaze frequency tended to increase, and the average fixation duration tended to decrease as the number of experienced cases increased. Inexperienced operators tend to fix their gaze when they are operators than when they are assistants. More experienced operators tended to look at the microcatheter longer in the coil insertion task. The eye-tracking analysis may be useful for operator training in neuroendovascular therapy. Experts may have moved their eyes more frequently than trainees to gaze at the right place. In the future, it will be necessary to collect gaze data for more operators in various tasks.

The usefulness of three-dimensional fusion imaging of spinal arteriovenous malformation by a workstation connected to angiography systems.

Digital subtraction angiography (DSA) is the most useful technique for diagnosing spinal arteriovenous malformations (AVM). In recent years, with the improvement of imaging capabilities, the usefulness of three-dimensional (3D) imaging by fusing various modalities has been recognized. The use of 3D fusion imaging with a workstation connected to an angiography system has been reported in many cases of intracranial disease, but less frequently for spinal AVM. In this article, we describe two illustrative cases of spinal AVM in which 3D fusion imaging was useful for treatment. Although 3D fusion images using the system have the disadvantage that only a maximum of two images can be fused, it provides spinal surgeons with useful information for preoperative evaluation in a small amount of time.

Butterfly needle tap and suction (BTS) technique: a treatment for recurrent chronic subdural hematoma after burr hole craniostomy.

BACKGROUND: In this study, we propose a butterfly needle tap and suction (BTS) technique for recurrent chronic subdural hematoma (CSDH) as an alternative to reoperation with burr hole craniostomy (BHC) and investigate its efficacy and safety. The procedure involves percutaneous puncture through the burr hole created during the previous surgery and subsequent hematoma evacuation using a butterfly needle. METHODS: This retrospective study included patients who underwent BTS for CSDH at Ogaki Municipal Hospital between January 2017 and December 2020. The follow-up CT scans were reviewed after several weeks. We evaluated the number of percutaneous punctures required to resolve CSDH during the BTS technique, the volume of the evacuated hematoma, and procedure-related complications. RESULTS: Twenty-six patients were enrolled in the study, 21 of whom achieved resolution of the hematoma using punctures with the BTS technique alone (mean, 2.2 ± 1.5). Five patients had a recurrence of hematoma after one or more punctures during the BTS technique, and they underwent reoperation with BHC according to the surgeon's decision or patient requests. Among the 55 punctures, 43.0 ± 16.0 ml of hematoma was evacuated per puncture. The evacuated hematoma volume was 41.9 ± 16.4 ml in the BTS-alone group and 49.4 ± 12.9 ml in the reoperation group, with no significant difference (p = 0.25). Three patients complained of a headache during the puncture procedure, and no other complications, including intracranial hemorrhage or infection, were reported therein. CONCLUSIONS: The BTS technique is an effective alternative to reoperation with BHC.

Characteristic image on cerebral angiography in ruptured blood blister-like aneurysms.

OBJECTIVE: To evaluate the static and dynamic features of blood blister-like aneurysms (BBAs) using cerebral angiography to identify characteristic features to improve the diagnosis of these uncommon aneurysms. METHODS: Digital subtraction angiography (DSA) images were compared between patients with BBAs (n = 12, group A) and patients with unruptured paraclinoid aneurysms ≤ 5 mm in size treated by endovascular procedures (n = 12, group B). DSA images were assessed for irregularities in the diameter of the parent artery and delayed inflow and outflow of contrast medium in the aneurysm. Enlargement of the aneurysm and morphological changes from the first assessment were also evaluated in patients with BBAs. RESULTS: Compared to the group B, group A had a higher proportion of irregular vessel diameter (p = 0.013) and the delayed contrast medium outflow (p = 0.014). As well, stagnation of contrast medium along the aneurysm wall was a characteristic finding of BBAs, even for small aneurysms. CONCLUSION: Irregular morphological features of the parent artery and delayed contrast medium outflow as characteristic findings of ruptured BBAs may improve the diagnosis of these uncommon aneurysms, which remains challenging in practice.

Antiplatelet therapy discontinuation after stent-assisted coil embolization for intracranial aneurysms: a single-center, long-term, retrospective, observational study.

OBJECTIVE: The protocol for antiplatelet therapy after stent-assisted coil embolization (SACE) for intracranial aneurysms is not well established. In particular, the indications for single antiplatelet therapy (SAPT) discontinuation remain controversial. The authors investigated the long-term outcomes of SAPT discontinuation after SACE among patients at a single institution. METHODS: Patients who underwent SACE during the period from 2010 to 2020 and who were followed up for > 1 year were included in this study. The delayed ischemic and hemorrhagic complication rates were examined during follow-up. Moreover, the risk factors of antiplatelet therapy reduction or discontinuation and the outcomes of SAPT discontinuation were examined. RESULTS: In total, 240 patients were included in the analysis. The average patient age was 60.3 years, and the average follow-up period was 46.7 months. Nine (3.8%) patients presented with symptomatic delayed ischemic complication, and 3 (1.3%) patients experienced a decline in modified Rankin Scale score. The stent configuration (T- or Y-stent) was the only risk factor associated with delayed ischemic complication (p < 0.001). SAPT was discontinued in 147 (71.7%) of 205 patients who were followed up for > 2 years, and no ischemic complications were observed. CONCLUSIONS: It is safe to discontinue SAPT in patients without ischemic complications and with stable intraaneurysmal signals on MRA 2 years after SACE. The T- or Y-stent is a high-risk factor for delayed ischemic complications, and antiplatelet therapy reduction or discontinuation should be cautiously considered.