OBJECTIVE: The paucity of literature comparing Woven EndoBridge (WEB) embolization to microsurgical clipping for anterior circulation wide-neck bifurcation aneurysms (WNBAs) underscores the need for further investigation into the optimal management of this patient subpopulation. The objective of this study was to compare the rate of endovascular and microsurgical treatment of WNBAs before and after the introduction of the WEB device. In addition, the authors performed a comparison of demographics, aneurysm characteristics, and treatment outcomes in patients before and after the introduction of the WEB device.
METHODS: This study was a retrospective review of the usage rate of different treatment modalities for WNBAs before and after the WEB device was approved by the US FDA on September 27, 2018.
RESULTS: The study cohort comprised 235 patients with anterior circulation WNBAs treated at the authors\' institution, including 127 aneurysms treated pre-WEB and 108 treated post-WEB. Generally, the rate of endovascular treatment of anterior circulation WNBAs was significantly higher post-WEB (86.1% vs 46.5%, p < 0.001), while the rate of clipping was significantly lower (13.9% vs 53.5%, p < 0.001). During follow-up, the rate of adequate aneurysm occlusion (Raymond-Roy occlusion classification [RROC] grades 1 and 2) was nonsignificantly higher in the post-WEB cohort (83.9% vs 78.5%, p = 0.34), while the rate of RROC grade 3 was nonsignificantly higher in the pre-WEB cohort (21.5% vs 16.1%, p = 0.34). Additionally, and although nonsignificant, the rates of recurrence (pre-WEB 25.3% vs post-WEB 14.9%, p = 0.12) and retreatment (pre-WEB 22.8% vs post-WEB 14.9%, p = 0.22) were higher in the pre-WEB cohort. Recurrence was assessed before retreatment.
CONCLUSIONS: After the introduction of the WEB device, the rate of endovascular treatment of WNBAs increased while the rate of microsurgical clipping decreased. It is essential for neurointerventionalists to become familiar with the indications, advantages, and shortcomings of all these different techniques to be able to match the right patient with the right technique to produce the best outcome.

BACKGROUND: Flow diversion for bifurcation aneurysms requires excluding one of the branches from the parent artery, raising concern for ischemic events. We evaluated thromboembolic events and their relationship with covering the origin of the posterior cerebral artery (PCA).
METHODS: This retrospective analysis included patients with confirmed basilar and proximal PCA aneurysms treated with flow diversion between 2013 and 2023. Procedures were classified according to the coverage of the origin of the PCA. Thromboembolic events associated with the excluded PCA were evaluated.
RESULTS: Of the total 28 aneurysms included, 7 were at the basilar tip, 16 in the basilar trunk, and 5 in the first segment of the PCA; 15 were treated by excluding one of the PCAs. Dual antiplatelet therapy included aspirin and ticagrelor (57.1%), aspirin and clopidogrel (35.7%), or aspirin and prasugrel (3.57%). Complete and near-complete aneurysm occlusion was achieved in 80.8% of the aneurysms treated at a median follow-up of 12.31 months. Thromboembolic complications occurred in 3 patients (2 with basilar perforator stroke and 1 with basilar in-stent thrombosis). However, the difference in these events was not statistically significant between patients with PCA coverage and those without (P = 0.46). Diminished flow and a lack of flow was seen in 8 and 7 of the covered vessels, respectively. A modified Rankin scale score of ≤2 was reported for 89.3% of patients at a median clinical follow-up of 5.5 months.
CONCLUSIONS: The incidence of thromboembolic events is high in distal basilar and proximal PCA aneurysms; however, PCA coverage was not associated with their occurrence. There was no difference in postprocedural disability between patients whose aneurysms were treated by excluding one of the PCAs and those who were not.

Wide-neck bifurcation aneurysms (WNBAs) are sometimes challenging to treat. During endovascular treatment, it is important to prevent coil deviation and preserve normal vessels. Adjunctive balloon- and stent-assisted techniques have been developed. A meta-analysis of endovascular treatments of WNBAs revealed that only 40% of patients had complete occlusion. Recently, novel devices have been developed to expand the range of treatment options. Flow-diverter stents and intra-aneurysmal flow disruption devices do not require coils; however, coil embolization remains the standard procedure used by many neurointerventionists. This review describes the recent trends in adjunctive techniques for supporting coil embolization for WNBAs. We referred to literature on balloon-assisted techniques, stent-assisted techniques, Y-stenting, PulseRider, Barrel stents, Comaneci temporary stents, pCONUS, and eCLIPs. These reports showed that adequate embolization rates were generally greater than 80%, and the complete occlusion rate was as high as 94.6%. All devices had a relatively high occlusion rate; however, it may be inaccurate to simply compare each device because of the heterogeneity of the studies. It is important to select the best treatment for each individual case by considering not only literature-based efficacy and safety but also patient background, aneurysm characteristics, and operator experience.

UNASSIGNED: Aneurysm size is considered a risk factor for aneurysm rupture, and even small aneurysms may rupture, especially bifurcation aneurysms (BAs), which are occasionally detected. Therefore, we aimed to investigate the predictors of retreatment after coil embolization for unruptured BAs, with a particular focus on the absolute and relative size of the aneurysm (size ratio [SR]).
UNASSIGNED: To evaluate the predictors of retreatment, patients were divided into two groups: those with and those without retreatment. Patient characteristics and radiographic assessments were compared between the groups. SR was defined as the ratio of the maximum aneurysm diameter and the average diameter of the parent artery.
UNASSIGNED: Overall, 181 unruptured BAs in 176 patients were investigated. The mean age of the patients was 63.8 ± 9.6 years. The mean aneurysm size and SR were 7.18 ± 2.94 mm and 2.49 ± 1.32, respectively. Further, 12 aneurysms with retreatment (6.6 %) and 169 aneurysms without retreatment were compared. In univariate analysis, SR was significantly higher in the group with retreatment (P = 0.02), but aneurysm size was not significantly different between the groups (P = 0.09). Multivariable analysis revealed that SR > 2.6 was a significant predictor of retreatment (P = 0.03; odds ratio: 10.41; 95 % confidence interval: 2.1-51.73).
UNASSIGNED: This study showed that SR influences retreatment after coil embolization for unruptured BAs. Therefore, if the aneurysm size and parent artery diameter were small, as in cases with a large SR, meticulous follow-up after coil embolization is required to detect recurrence and recanalization.

Aneurysm occlusion with microcoils is an effective and safe procedure. However, bifurcation aneurysms usually have a wide neck, and their occlusion is still a difficult objective.
To evaluate the efficacy and safety of bifurcation stents in the treatment of basilar bifurcation aneurysms.
A retrospective analysis included 34 patients with basilar bifurcation aneurysms between 2016 and 2022. The pConus bifurcation stent was used as a stent-assistance for endovascular occlusion of aneurysms with microcoils. We analyzed technical features of stent implantation and clinical results of endovascular treatment. Mean aneurysm dimension was 8.4 mm, neck size - 4.6 mm. Preoperative MSR score 0-2 was observed in 94.7% of patients, 3-5 scores - in 5.3% of patients.
There were no significant changes in functional status early after surgery (MSR grading system). Total aneurysm occlusion was achieved in 67.6% of patients, subtotal - 17.6% of cases, partial - 14.8%. There were no technical or early postoperative clinical complications. Six months after surgery, total occlusion was observed in 77.8% of patients, subtotal occlusion - 14.8%, partial occlusion - 4%. MSR score 0-2 was observed between 3 and 12 months after surgery. One patient died from other cause rather aneurysm. Redo intervention due to aneurysm recanalization was performed in 1 patient.
The pConus bifurcation stent is effective and safe in endovascular treatment of basilar bifurcation aneurysms of the most complex configuration. There was a minimal risk of aneurysm recanalization in long-term postoperative period.
Окклюзия аневризмы микроспиралями зарекомендовала себя как эффективный и безопасный метод лечения аневризм. Однако аневризмы, расположенные на бифуркации сосудов, как правило, имеют широкую шейку, и их выключение остается сложной задачей.
Оценить эффективность и безопасность применения бифуркационных стентов в лечении аневризм развилки основной артерии.
Проведен ретроспективный анализ данных 34 пациентов с аневризмами бифуркации базилярной артерии, пролеченных в ФГАУ «Национальный медицинский исследовательский центр нейрохирургии им. акад. Н.Н. Бурденко» Минздрава России в период с 2016 по 2022 г. В качестве стент-ассистенции при эндоваскулярной окклюзии аневризм микроспиралями использовался бифуркационный стент pConus. Осуществлена оценка технических особенностей имплантации стента и клинических результатов эндоваскулярного лечения. Средний размер аневризм составил 8,4 мм, средний размер шейки — 4,6 мм. До операции состояние 94,7% пациентов соответствовало 0—2 баллам по модифицированной шкале Ренкина (МШР), а 5,3% — 3—5 баллам.
При оценке функционального статуса по МШР в раннем послеоперационном периоде значимых изменений не выявлено. Тотальная окклюзия аневризмы достигнута у 67,6% пациентов, субтотальная — в 17,6% случаев, частичная — в 14,8%. Технических и ранних послеоперационных клинических осложнений не было. Через 6 мес после операции тотальная окклюзия наблюдалась у 77,8% пациентов, субтотальная — у 14,8%, а частичная — у 4% больных. В сроки от 3 до 12 мес состояние наблюдаемых по МШР соответствовало 0—2 баллам. Один пациент скончался по причине, не связанной с аневризмой. Повторное вмешательство в связи с реканализацией аневризмы было выполнено у 1 больного.
Использование бифуркационного стента pConus является эффективным и безопасным методом стент-ассистенции при эндоваскулярном лечении аневризм бифуркации базилярной артерии наиболее сложной конфигурации. В отдаленном периоде после операции отмечен минимальный риск реканализации аневризм.

Wide-neck aneurysms (WNA) often require advanced open surgical and endovascular techniques to achieve adequate aneurysm occlusion. Microsurgical treatment often requires advanced clip configurations. Occasionally, more complex open surgical techniques are required. Advancements in endovascular therapies (EVT) and devices have expanded endovascular treatment options for WNAs and have improved aneurysm occlusion rates compared with primary coiling. Certain EVT require dual antiplatelet therapy, limiting their use in the ruptured setting. Evidence suggests that microsurgical treatment should remain a consideration for treatment of ruptured WNAs, but perhaps with novel endovascular techniques and devices, EVT should be first-line treatment in the unruptured setting.

BACKGROUND: Bifurcation aneurysms represent an ongoing endovascular challenge with a variety of techniques and devices designed to address them. We present our multicenter series of the pCONUS2 and pCONUS2 HPC devices when treating bifurcation aneurysms.
METHODS: We performed a retrospective review of our prospectively maintained databases at 3 tertiary neurointerventional centers to identify all patients who underwent coil embolization with the pCONUS2 or pCONUS2 HPC device between February 2015 and August 2021. We recorded baseline demographics, aneurysm data, complications, immediate and delayed angiographic results.
RESULTS: We identified 55 patients with 56 aneurysms, median age 63 years (range 42-78 years), 67.3% female (n = 37). The commonest aneurysm location was the MCA bifurcation (n = 40, 71.4%). Average dome height was 8.9 ± 4.2 mm (range 3.2-21.5 mm), average neck width 6.4 ± 2.5 mm (range 2.6-14 mm), and average aspect ratio 1.3 ± 0.6 (range 0.5-3.3). The pCONUS2 was used in 64.3% and the pCONUS2 HPC in 35.7%. The procedural technical success rate was 98.2%. Intraoperative complications occurred in 5 cases (8.9%), 4 of which were related to the coils with partial thrombus formation on the pCONUS2 HPC seen in 1 case that was resolved with heparin. In relation to the procedure and treatment of the aneurysm the overall permanent morbidity was 1.8% (n = 1/55) and mortality 0%. Delayed angiographic follow-up (48 aneurysms) at median 12 months postprocedure (range 3-36 months) demonstrated adequate occlusion of 83.4% of aneurysms.
CONCLUSIONS: The pCONUS2 and pCONUS2 HPC devices carry a high technical success rate, low complication and retreatment rate, and good rates of adequate occlusion. Larger prospective confirmatory studies are required.

BACKGROUND: Wide-necked middle cerebral artery bifurcation aneurysms pose specific challenges to endovascular management. Surgical clipping remains the standard treatment approach for these aneurysms in many centers. While recent data suggests the endovascular treatment may be comparable, a prospective datapoint has been lacking.
METHODS: The Penumbra SMART registry, a prospective, multi-center, single-arm outcomes registry of Penumbra coil-treated aneurysms, was queried for endovascularly treated MCA bifurcation aneurysms with wide necks (dome:neck ratio <2 or neck >4 mm). Safety and efficacy outcomes were summarized for ruptured and unruptured aneurysms, including rupture, complication rate, and 1-year occlusion outcomes.
RESULTS: Seventy-two aneurysms across 31 sites were enrolled. Of these, a total of 15 presented as ruptured aneurysms. Serious adverse events were reported in 21 (29.2%) of patients, with 8 (11.1%) attributed to the device/procedure. Immediately postoperatively, 75.0% of cases achieved \"adequate\" Raymond Roy Class I (40.3%) or II (34.7%) occlusion outcomes. Of the 72 patients treated, 60 (83.3%) underwent follow-up angiography at 1 year, and among these, 95.0% had 1-year occlusion outcomes of Raymond Roy Class I (71.7%) or II (23.3%). A total of 6 aneurysms (10.0%) were required or were planned for retreatment at the last follow-up.
CONCLUSIONS: This study represents the most significant prospective sample of endovascularly treated wide-neck MCA bifurcation aneurysms conducted to date. It supports the safety and efficacy of endovascular treatment of these aneurysms.

Intracranial aneurysm projected posteriorly is associated with high risk of aneurysm rupture. In order to investigate the biomechanical mechanisms for the adverse event, three-dimension intracranial cerebral aneurysms were constructed based on clinical data, and we numerically compared effect of location, position, size, and shape of aneurysm on hemodynamic conditions including velocity, pressure, and wall shear stress (WSS). The numerical results showed that the aneurysm projected posteriorly even at small sizes led to abnormal hemodynamic environment, which was featured by a local high pressure and stress concentration near aneurysm neck area. Moreover, the one located at the proximal A1 segment and ellipsoidal aneurysm would further worse local hemodynamic environment, causing high local stresses. These findings indicated the potential mechanical mechanism for high rupture rate of the aneurysms projected posteriorly, underscoring importance of early and accurate diagnosis and promptly treatment for improved the clinical outcome, even if these aneurysms are of small sizes.

BACKGROUND: Accurate sizing of the Woven EndoBridge (WEB) device is of critical importance as it determines procedural safety and successful occlusion of wide neck bifurcation aneurysms. The aim of this study was to assess the ability of aneurysm volume to assist in accurate WEB size selection.
METHODS: All patients with an intracranial aneurysm treated with the WEB SL or WEB SLS device between March 2019 and October 2019 were identified for this retrospective study. Aneurysm volumes were calculated with auto-segmentation using a three-dimensional volume rendering program on an independent Syngo workstation (Siemens Healthineers AG). Pearson correlation coefficients were calculated for aneurysm auto-segmented volumes and WEB volumes, as well as for aneurysm height × width and WEB height × width. Follow-up angiographic outcomes were collected at 6-9 months post-procedure.
RESULTS: Twenty-nine aneurysms were evaluated by 3D rotational angiography. The correlation coefficient with WEB size was larger for auto-segmented aneurysm volumes (r = 0.979) compared to height × width measurements (r = 0.867). Using Fisher r-to-z transformations, we found the difference between the two correlations to be statistically significant (p = 0.0007). Follow-up angiography available in 13 subjects demonstrated an 85% complete aneurysm occlusion rate.
CONCLUSIONS: Aneurysm volumes are highly correlated with WEB volumes, with auto-segmentation volumes displaying statistically significant difference against conventional height by width measurements. These results suggest that volumetric measurements of aneurysm size provide a useful adjuvant measure to assist in appropriate size selection of the WEB device.