Initial Experience with the Derivo 2Heal Flow Diverter under Standard or Reduced-Dose Single Antiplatelet Therapy.

BACKGROUND AND PURPOSE: Flow diverters with surface modifications or coatings have been recently introduced to clinical practice with the expectation that they can reduce the rate of thromboembolic complications and residual aneurysms. The purpose of this study is to evaluate the utility of the Derivo 2Heal (D2H) device, a new fibrin and heparin-coated flow diverter. MATERIALS AND METHODS: Patients treated by a single operator by using the D2H were retrospectively evaluated for demographic data, aneurysm characteristics, procedural variables, and follow-up data. All patients were treated by using a single D2H, monitored by platelet function testing and kept under single antiplatelet therapy with regular or half-dose clopidogrel or prasugrel after the procedure. RESULTS: Twenty patients with 26 aneurysms were treated. Three presented acutely with subarachnoid hemorrhage. Adjunctive devices were used in 6 patients. There were no technical failures and 2 periprocedural self-limited nonthrombotic minor adverse events. During follow-up, 1 of the acutely ruptured aneurysms reruptured, and 1 patient had a visual TIA. All patients were doing well clinically (19 with mRS of 0 and 1 with 1) at the last follow-up after discharge. The rates of total occlusion on very early angiographic (MRA/CTA or DSA, mean: 2.4 months), DSA (mean: 5.8 months), and midterm angiographic (mean: 14.5 months) follow-up for all versus uncoiled aneurysms were 68% versus 70%, 77.8% versus 90.0%, and 91.7% versus 90.1%, respectively. CONCLUSIONS: The absence of permanent neurologic deficits in the periprocedural period and favorable occlusion rates in this preliminary study suggest that the novel coating comprising fibrin and heparin may have the potential to increase the safety and efficacy of flow diversion and needs to be further studied by comparing the D2H device with its bare counterpart and other coated or surface-modified flow diverters.

Non-routine thrombectomy in pediatric arterial ischemic stroke.

PURPOSE: Unlike in adults, the indications and techniques for mechanical thrombectomy for arterial ischemic stroke (AIS) in children are not clearly established. The medical and interventional management of children with acute large vessel occlusion may entail the modification of the standardized management of this condition in adults. We present six cases of children who underwent non-routine thrombectomy for AIS. METHODS: We retrospectively reviewed the records of children diagnosed with AIS between 2015 and 2023 and evaluated patient characteristics, procedural technical data, and final clinical outcomes. Procedures deviating from the current definition and indications for AIS treatment in adults as well as previously reported pediatric thrombectomy cases were defined as non-routine thrombectomy. RESULTS: Seven non-routine thrombectomy procedures in six children were included in the study. The National Institutes of Health Stroke Scale scores on admission ranged from 4 to 35; no procedure-related mortality or major neurologic morbidity occurred. One child died of causes related to the initial severe heart failure and stroke; otherwise, all the children had a modified Rankin scale score of 0 to 1 at follow-up. Unique clinical and procedural features in our case series included presentation with acute stent occlusion (two children), bilateral simultaneous internal carotid artery occlusions associated with a unilateral tandem middle cerebral artery (MCA) occlusion (one child), MCA occlusion caused by thromboembolism of the atrial myxoma (one child), and very distal (one child) or delayed thrombectomy (two children). CONCLUSION: Modifications to the standard medical and interventional algorithms may be required for mechanical thrombectomy in children. CLINICAL SIGNIFICANCE: Referral centers specialized in pediatric neurology, pediatric anesthesia, and pediatric intervention are optimal for treating children using mechanical thrombectomy and for modifying the treatment, if required.

Use of a new low-profile coronary stent graft for the treatment of intracranial carotid blow-out.

A 50-year-old male patient with a history of transcranial surgery and subsequent radiotherapy for a pituitary adenoma presented with repetitive pulsatile nasal bleeding. A right cavernous segment pseudoaneurysm was discovered on the angiogram, and the patient failed the balloon occlusion test. A Papyrus (Biotronik, Berlin, Germany) stent graft, which is approved for coronary interventions, was successfully deployed over a coaxial guiding system during the emergent treatment of the false aneurysm. The patient tolerated the procedure well and nasal bleeding did not recur after the procedure. At one-year angiographic follow-up, the stent graft was patent and there was no evidence of recanalization of the false aneurysm.

Correlation Between Quantitative Parameters Obtained by Dual Energy Spectral CT and Prognostic Histopathological Factors and Biomarkers in Breast Cancer.

RATIONALE AND OBJECTIVES: To investigate the correlation between quantitative parameters obtained by dual energy spectral computed tomography (DESCT) and various histopathological factors and biomarkers associated with the prognosis of breast cancer. MATERIALS AND METHODS: Quantitative parameters such as iodine content (IC), normalized IC (nIC), iodine enhancement (IE) and normalized IE (nIE) were measured on virtual monochromatic images and iodine mapping images obtained from DESCT in 116 female breast cancer patients. The relationship between these parameters and prognostic biomarkers such as estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status and Ki67 levels, as well as the correlation with histological grade (HG), lymphovascular invasion (LVI), and metastatic axillary lymphadenopathy (LAP) were evaluated. RESULTS: ER-negative tumors had significantly higher values of IC, nIC, IE, and nIE compared to ER-positive tumors. PR-negative tumors had significantly higher values of IE and nIEc compared to PR-positive tumors. HER2 overexpressed and Ki-67 high proliferation tumors showed significantly higher values of all quantitative parameters compared to HER2 negative and Ki-67 low proliferation tumors. All quantitative parameters were significantly higher in HG 3 tumors, tumors with detected LVI, and tumors with metastatic axillary LAP compared to low-grade tumors, LVI-negative tumors and tumors without metastatic axillary lymph nodes, respectively. CONCLUSION: Quantitative parameters of IC and IE obtained from DESCT have shown potential for predicting prognosis in breast cancer patients. Higher values of these parameters have been found to correlate with poor prognostic biomarkers and histopathological features. These results suggest that quantitative DESCT imaging may offer an additional benefit in the noninvasive prediction of breast cancer prognosis.

Implications of serial magnetic resonance imaging in the management of a newborn with vein of Galen aneurysmal malformation and a review of the relevant literature.

BACKGROUND: Despite advanced endovascular methods and comprehensive intensive care in the neonatal vein of Galen aneurysmal malformation, overall mortality ranges between 37-63% in treated patients with 37-50% of survivors possessing poor neurologic outcomes. These findings stress the need for more accurate and timely recognition of the patients who may and may not benefit from aggressive intervention. CASE: This case report presents a newborn with a vein of Galen aneurysmal malformation whom antenatal and postnatal follow-up included serial magnetic resonance imaging (MRI) including diffusion-weighted series. CONCLUSIONS: Given the experience from our current case and in light of the relevant literature, it is plausible that diffusion-weighted imaging studies may widen our perspective on dynamic ischemia and progressive injury occurring within the developing central nervous system of such patients. Meticulous identification of patients may favorably influence the clinical and parental decision on early delivery and prompt endovascular treatment versus aiding avoidance of further futile interventions both antenatally and postnatally.

Non-Hermitian Hamiltonians for linear and nonlinear optical response: A model for plexcitons.

In polaritons, the properties of matter are modified by mixing the molecular transitions with light modes inside a cavity. Resultant hybrid light-matter states exhibit energy level shifts, are delocalized over many molecular units, and have a different excited-state potential energy landscape, which leads to modified exciton dynamics. Previously, non-Hermitian Hamiltonians have been derived to describe the excited states of molecules coupled to surface plasmons (i.e., plexcitons), and these operators have been successfully used in the description of linear and third order optical response. In this article, we rigorously derive non-Hermitian Hamiltonians in the response function formalism of nonlinear spectroscopy by means of Feshbach operators and apply them to explore spectroscopic signatures of plexcitons. In particular, we analyze the optical response below and above the exceptional point that arises for matching transition energies for plasmon and molecular components and study their decomposition using double-sided Feynman diagrams. We find a clear distinction between interference and Rabi splitting in linear spectroscopy and a qualitative change in the symmetry of the line shape of the nonlinear signal when crossing the exceptional point. This change corresponds to one in the symmetry of the eigenvalues of the Hamiltonian. Our work presents an approach for simulating the optical response of sublevels within an electronic system and opens new applications of nonlinear spectroscopy to examine the different regimes of the spectrum of non-Hermitian Hamiltonians.

Dual ophthalmic arteries: a new case.

We report one retinoblastoma patient with dual ophthalmic arteries (also known as "double ophthalmic arteries") arising from the internal carotid artery which fuse with each other inside the orbit. The caudal ophthalmic artery with larger caliber originated from the cavernous segment of internal carotid artery and passed through the superior orbital fissure. The cranial and tiny one arose more cranially from the supraclinoid internal carotid artery and passed through the optic canal. After superselective catheterization, frank anastomosis was shown between two ophthalmic arteries and the central retinal artery arose from the cranial one. To the best of our knowledge, this case is the first observation of a dual ophthalmic artery with cavernous/supracavernous origins fusing with each other proven by superselective ophthalmic angiography. Whether there is an anastomosis between two ophthalmic arteries is important for deciding which artery to be selected for intraarterial treatment. In cases of retinoblastoma, detailed angiographic analysis may be essential to examine the orbital arterial system and to avoid unexpected complications during intraarterial chemotherapy.

Strong Coupling of Carbon Quantum Dots in Liquid Crystals.

Carbon quantum dots (CDs) have recently received a tremendous amount of interest owing to their attractive optical properties. However, CDs have broad absorption and emission spectra limiting their application ranges. We herein, for the first time, show synthesis of water-soluble red emissive CDs with a very narrow line width (∼75 meV) spectral absorbance and hence demonstrate strong coupling of CDs and plasmon polaritons in liquid crystalline mesophases. The excited state dynamics of CDs has been studied by ultrafast transient absorption spectroscopy, and CDs display very stable and strong photoluminescence emission with a quantum yield of 35.4% and a lifetime of ∼2 ns. More importantly, we compare J-aggregate dyes with CDs in terms of their absorption line width, photostability, and ability to do strong coupling, and we conclude that highly fluorescent CDs have a bright future in the mixed light-matter states for emerging applications in future quantum technologies.

Topological engineering of terahertz light using electrically tunable exceptional point singularities.

The topological structure associated with the branch point singularity around an exceptional point (EP) can provide tools for controlling the propagation of light. Through use of graphene-based devices, we demonstrate the emergence of EPs in an electrically controlled interaction between light and a collection of organic molecules in the terahertz regime at room temperature. We show that the intensity and phase of terahertz pulses can be controlled by a gate voltage, which drives the device across the EP. Our electrically tunable system allows reconstruction of the Riemann surface associated with the complex energy landscape and provides topological control of light by tuning the loss imbalance and frequency detuning of interacting modes. Our approach provides a platform for developing topological optoelectronics and studying the manifestations of EP physics in light-matter interactions.

Cortical Subarachnoid Hemorrhage in Behcet's Disease.

OBJECTIVE: Cortical subarachnoid hemorrhage (cSAH) can be resulted from by a wide variety of causes. A cSAH probably associated with Behcet's disease is herein reported for the first time. CASE REPORT: A 58-year-old male with stable Behcet's disease evaluated for sudden onset headache. Emergency computed tomography disclosed cSAH in the left frontal sulci. A ruptured middle cerebral artery cortical branch aneurysm was found. Surprisingly, this aneurysm obliterated completely after diagnostic catheter angiography. CONCLUSION: This case highlights three important points; First, non-mycotic (non-infectious) distal cerebral artery aneurysms may rarely cause cSAH. Second, distal dissecting aneurysms may rarely become obliterated after diagnostic cerebral angiography. Third, such aneurysms may be one of the long-term consequences of vascular inflammation in Behçet's disease.

Carotid Artery-Cavernous Segment Injury during an Endoscopic Endonasal Surgery: A Case Report and Literature Review of the Overlooked Option for Surgical Trapping in the Hyperacute Phase.

Internal carotid artery (ICA) injury is a catastrophic complication of endoscopic endonasal surgery (EES). However, its standard management, emergent endovascular treatment, may not always be available, and the transnasal approach may be insufficient to achieve hemostasis. A 44-year-old woman with pituitary adenoma underwent EES complicated with the ICA cavernous segment injury (CSI). In urgent intraoperative angiogram, a good collateral flow from the contralateral carotid circulation was observed. Due to the unavailability of intraoperative embolization, emergent surgical trapping was performed by combined transcranial and cervical approach. The patient recovered but later developed a giant cavernous pseudoaneurysm. During the pseudoaneurysm embolization, ICA was directly accessed via a 1.7-F puncture hole using a bare microcatheter technique. Then, both the aneurysm and parent artery were obliterated with coils. At the 4-year follow-up, the patient was asymptomatic without a residual tumor. To our knowledge, this is the first case of ICA-CSI during EES successfully treated with ICA trapping as a lifesaving urgent surgery that achieved a complete recovery after a pseudoaneurysm embolization. Although several studies reported that EES-related ICA-CSIs with percutaneous carotid artery access, neither our surgical salvage technique nor our carotid access and tract embolization techniques were previously described.

Multispectral Graphene-Based Electro-Optical Surfaces with Reversible Tunability from Visible to Microwave Wavelengths.

Optical materials with colour-changing abilities have been explored for display devices1, smart windows2,3, or modulation of visual appearance4-6. The efficiency of these materials, however, has strong wavelength dependence, which limits their functionality to a specific spectral range. Here, we report graphene-based electro-optical devices with unprecedented optical tunability covering the entire electromagnetic spectrum from the visible to microwave. We achieve this non-volatile and reversible tunability by electro-intercalation of lithium into graphene layers in an optically accessible device structure. This unique colour-changing capability, together with area-selective intercalation, inspires fabrication of new multispectral devices, including display devices and electro-optical camouflage coating. We anticipate that these results provide realistic approaches for programmable smart optical surfaces with a potential utility in many scientific and engineering fields such as active plasmonics and adaptive thermal management.

Dual Stenting with New-Generation Stents for Aneurysm Embolization in Acute Subarachnoid Hemorrhage.

OBJECTIVE: Endosaccular treatment is the backbone of endovascular treatment for acutely ruptured aneurysms. Stent-assisted coiling is a niche technique in this context. Data on X-stenting or Y-stenting (dual crossing stenting, DCS) in the acute phase after subarachnoid hemorrhage (aSAH) are scarce, and the impact of stent properties on the outcome is unknown. We retrospectively evaluated the clinical and imaging results of DCS in patients treated for aSAH. METHODS: Patients with aSAH treated with DCS were evaluated retrospectively. Patient and procedural characteristics were evaluated to determine clinical outcomes, associated complications, and follow-up imaging findings. RESULTS: Sixteen procedures (16 patients; 10 women, mean age 55.8) were performed within 3.2 ± 2.6 days (range 1-10 days) of aSAH. Only the latest generation of intracranial stents (dual Neuroform Atlas-12 cases, dual Leo Baby-2 cases, Neuroform Atlas with Acclino Flex, or Leo Baby-2 cases) were used. Technical success rate was 100%; however, 25% of the procedures were complicated, leading to adverse events in 3 procedures (18.8%; 2 stent thrombosis, 1aneurysm rupture). Procedure-related morbidity and mortality and overall permanent morbidity and mortality were 6.3%, none, 6.3%, and 12.5%, respectively. No additional neurologic events were noted on a mean clinical follow-up of 160 ± 156 (range: 1-540) days. CONCLUSIONS: Our findings and the patient-by-patient data we extracted from the literature suggest that DCS can be performed with new-generation, low-profile stents in aSAH if a definite procedural risk is acceptable for a specific patient. New-generation open-cell stent combinations appear as a viable choice for DCS in aSAH.

Stroke Mechanism in COVID-19 Infection: A Prospective Case-Control Study.

BACKGROUND: The characteristics and pathophysiological mechanisms involved in acute ischemic stroke in patients with COVID-19 infection have not been fully clarified. We prospectively studied the phenotypic and etiological features of acute stroke occurring in COVID-19 infection. PATIENTS & METHODS: Within nine months starting from April-2020, the presence of COVID-19 infection was determined by thoracic CT and SARS-CoV-2 PCR in all acute stroke cases managed in a single tertiary center. Consecutive and prospective data on vascular risk factors/comorbidities, in-hospital quality metrics, discharge outcomes, etiological subclassification and blood markers of thrombosis / inflammation were compared in 44 COVID-19 positive cases (37 acute ischemic stroke, 5 TIA, 2 intracerebral hematoma) and 509 COVID-19 negative patients (355 ischemic, 105 TIA, 44 hematoma and 5 stroke mimic). RESULTS: COVID-19 positive patients had more severe strokes, delayed hospital admission, longer hospital stay, higher mortality rates, but had similar vascular risk factors/comorbidities frequency, thrombolysis/thrombectomy utilization rates, metrics, and stroke etiological subtype. They had significantly higher CRP, fibrinogen, ferritin, leukocyte count and lower lymphocyte count. No difference was detected in aPTT, INR, D-dimer, platelet, hemoglobin, homocysteine levels and ANA, anti-dsDNA antibody and ENA panel positivity rates. Anti-phospholipid antibodies have been studied in 70% of COVID-19 positive and all cryptogenic patients, but were never found positive. Tests for coagulation factor levels and hereditary thrombophilia did not show major thrombophilia in any of the stroke patients with COVID-19. CONCLUSION: We documented that there is no significant difference in etiological spectrum in acute stroke patients with COVID-19 infection. In addition, cryptogenic stroke and antiphospholipid antibody positivity rates did not increase.

Dual Testing to Achieve Low On-treatment Platelet Reactivity for Aneurysm Embolization.

BACKGROUND AND PURPOSE: Although point-of-care tests are used extensively to test platelet function before endovascular aneurysm treatment, their use and validity are still debated. We compared the results of two point-of-care tests (VerifyNow® and Multiplate®) for assessing patients treated with stents and flow diverters and determined their relation to periprocedural complications. METHODS: All patients undergoing treatment of intracranial aneurysms were tested using both methods and were retrospectively evaluated. Patients with acute subarachnoid hemorrhage and those who had to be maintained on anticoagulants for unrelated diseases were excluded. An acceptable level of platelet inhibition was required on both tests to commence with treatment, otherwise antiplatelet medication was adjusted to reach this level. RESULTS: Mean PRU (platelet reactivity units) and ADP AUC (adenosine diphosphate area under the aggregation curve) were 68 ± 66 and 23 ± 15, respectively, in 295 patients. Both tests showed a good correlation (r = 0.45). Both tests were able to predict hemorrhagic events but not ischemic events. When patients with very low reactivity (PRU < 60) were compared to the rest of the group, there were more hemorrhagic events in the first group but the overall rate of complications were similar (p = 0.27). CONCLUSION: In this largest study comparing two widely used commercial platelet function tests, the correlation between the tests were less than ideal; however, the very low platelet reactivity attained by the help of dual platelet testing did not result in an increased overall complication rate.

Laser assisted synthesis of anisotropic metal nanocrystals and strong light-matter coupling in decahedral bimetallic nanocrystals.

The advances in colloid chemistry and nanofabrication allowed us to synthesize noble monometallic and bimetallic nanocrystals with tunable optical properties in the visible and near infrared region of the electromagnetic spectrum. In the strong coupling regime, surface plasmon polaritons (SPPs) of metal nanoparticles interact with excitons of quantum dots or organic dyes and plasmon-exciton hybrid states called plexcitons are formed. Until now, various shaped metal nanoparticles such as nanorods, core-shell nanoparticles, hollow nanoparticles, nanoprisms, nanodisks, nanorings, and nanobipyramids have been synthesized to generate plasmon-exciton mixed states. However, in order to boost plasmon-exciton interaction at nanoscale dimensions and expand the application of plexcitonic nanocrystals in a variety of fields such as solar cells, light emitting diodes, and nanolasers, new plexcitonic nanocrystals with outstanding optical and chemical properties remain a key goal and challenge. Here we report laser-assisted synthesis of decahedral shaped noble metal nanocrystals, tuning optical properties of the decahedral shaped nanocrystals by galvanic replacement reactions, colloidal synthesis of bimetallic decahedral shaped plexcitonic nanocrystals, and strong plasmon-plasmon interaction in bimetallic decahedral shaped noble metal nanocrystals near a metal film. We photochemically synthesize decahedral Ag nanoparticles from spherical silver nanoparticles by using a 488 nm laser. The laser assisted synthesis of silver nanoparticles yields decahedral (bicolored) and prism (monocolored) shaped silver nanocrystals. The decahedral shaped nanoparticles were selectively separated from prism shaped nanoparticles by centrifugation. The optical properties of decahedral nanocrystals were tuned by the galvanic replacement reaction between gold ions and silver atoms. Excitons of J-aggregate dyes and SPPs of decahedral bimetallic nanoparticles strongly couple and hence decahedral shaped plexcitonic nanoparticles are prepared. In addition, localized SPPs of decahedral shaped bimetallic nanocrystals interact strongly with the propagating SPPs of a flat silver film and hence new hybrid plasmonic modes (plasmonic nanocavities) are generated. The experimental results are further fully corroborated by theoretical calculations including decahedral shaped plexcitonic nanoparticles and decahedral nanoparticles coupled to flat metal films.

Large Rabi splitting of mixed plasmon-exciton states in small plasmonic moiré cavities.

We report on exciton-plasmon coupling in metallic moiré cavities, both numerically and experimentally. Moiré cavities fabricated using double exposure laser interference lithography were filled with a molecular dye, J-aggregate. Polarization-dependent spectroscopic reflection measurements supported by simulations reveal strong coupling of organic dye excitons with cavity modes of the plasmonic moiré cavities. An anti-crossing at zero detuning, a clear indication of strong coupling, has been observed when the excitonic absorption band resonates with the cavity mode. Large Rabi splitting energies owing to the strong coupling of plasmons and excitons are clearly observed.

Validity of US measurements of cam-type femoroacetabular impingement parameters: a preliminary study in an asymptomatic adult population.

PURPOSE: To determine the accuracy of US for the quantitative parameters of cam-type femoroacetabular impingement (FAI) in an asymptomatic adult population, using MRI as the reference standard. MATERIALS AND METHODS: We prospectively evaluated 158 hips of 79 adult subjects (44 males, 35 females; age range 18-49 years) with a negative anterior impingement test. Two observers independently measured anterosuperior quadrant alpha angles and anterior femoral distances (AFDs) on both US and MRI. RESULTS: US measurements of alpha angle and AFD had a moderate-to-high positive correlation with MRI measurements and there was substantial and/or almost perfect agreement between observers on both imaging modalities. Anterior femoral distance measurements for both observers and alpha angles at MRI for Observer 1 showed no statistically significant difference between genders. CONCLUSION: Ultrasonography can be used for anterosuperior alpha angle and AFD measurements in asymptomatic adults. However, when used as the sole imaging method, its inherent limitations and possible discrepancies with MRI should be kept in mind.

Percutaneous drainage of retroperitoneal abscesses: variables for success, failure, and recurrence.

PURPOSE: We aimed to evaluate the success and failure rates and minor and major complications of percutaneous drainage of retroperitoneal abscesses. METHODS: Between 1990 and 2010, percutaneously drained 170 retroperitoneal abscesses in 150 patients (83 males, 67 females, median age 44.2 years, age range, 1-86 years) were included retrospectively. Percutaneous drainage of retroperitoneal abscesses was performed under the guidance of ultrasonography and fluoroscopy or computed tomography. Six abscesses were drained via single needle aspiration whereas 164 abscesses were drained via catheters of 6-14 F calibre using the Seldinger technique. RESULTS: When all retroperitoneal abscesses are considered, success rates were found as follows: 75.3% cure (128/170), 7.7% temporization (13/170), 4.1% palliation (7/170). Failure rate was 12.9% (22/170). Recurrence rate was 10.6% (18/170), and 13 of the recurred abscesses were treated via second session percutaneous drainage. Mortality rate was 2.7% (4/150). CONCLUSION: Percutaneous drainage is the first treatment option for retroperitoneal abscesses due to procedural reliability, elimination of need for general anesthesia, better tolerability, and lower morbidity and mortality rates compared with the surgical methods. High cure, temporization, or palliation rates can be obtained via imaging-guided percutaneous drainage for all retroperitoneal abscesses with a safe access route.

Y-Stent-Assisted Coiling With Low-Profile Neuroform Atlas Stents for Endovascular Treatment of Wide-Necked Complex Intracranial Bifurcation Aneurysms.

BACKGROUND: Y-stent-assisted coiling is one of the eligible techniques for the treatment of complex bifurcation aneurysms. In majority of previous literature, Y-stenting has been performed using stents that could be delivered through large profile microcatheters that are often difficult to manipulate during navigation through sharply angled side branches. Attempts to navigate with these large profile catheters might cause serious complications during Y-stenting procedure. OBJECTIVE: To investigate the safety, feasibility, and efficacy of Y-stent-assisted coiling procedure with Neuroform Atlas stents for the treatment of complex bifurcation aneurysms; Neuroform Atlas is a recently introduced open-cell stent that can be delivered though low-profile microcatheters. METHODS: We identified the patients with intracranial bifurcation aneurysms treated by Y-stent-assisted coiling procedure with Neuroform Atlas stents. We assessed the immediate postoperative and follow-up clinical and angiographic outcomes. We also investigated the periprocedural and delayed complications. RESULTS: A total of 30 aneurysms in 30 patients were included in the study. Y-stenting was successfully performed without any technical complications in all cases (100%). Immediate postprocedural angiography revealed total aneurysm occlusion in 83.3% of patients. The mean angiographic follow-up time was 11.8 mo. The last follow-ups showed complete occlusion in 93.3% of patients. There was no mortality in this study. A procedure-related complication developed in 6.7% and resulted in permanent morbidity in 3.3% of patients. CONCLUSION: Neuroform Atlas stent combines the advantages of low-profile deployment microcatheters with an open-cell structure to achieve a successful Y-stenting procedure. Y-stent-assisted coiling with Neuroform Atlas stents provides a safe and effective endovascular treatment for wide-necked complex bifurcation aneurysms.