Neuroform atlas stent treatment for 533 intracranial aneurysms in a large Chinese cohort: complication risk factor analysis.

BACKGROUND: The newest generation of Neuroform Atlas stent™ (Stryker, Fremont, California) represents a recent advance of cerebral laser-cut microstents for the treatment of intracranial wide-necked aneurysms, and postoperative complications have been observed among Western patients. We assessed predictors of complications, morbidity, and unfavourable outcomes in a large cohort of patients with aneurysms that were treated with Neuroform Atlas stents in China. METHODS: This retrospective study included subjects who were treated with Atlas stents in China from November 2020 to January 2022. RESULTS: A total of 522 consecutive patients (mean age, 58.9 ± 9.9 years; female, 65.3% [341/522]) with 533 aneurysms were included in the study. In the early postoperative period, the neurological morbidity rate was 7.3% (38/522), the ischaemic stroke rate was 5.0% (26/522), the aneurysm rupture subarachnoid haemorrhage rate was 2.3% (12/522), and the mRS score deterioration rate was 5.4% (28/522). The mortality rate was 0.8% (4/522) in the postoperative period. The rate of neurological morbidity during the follow-up period was 1.2% (6/486). In the multifactor prediction analysis, cerebral infarction, Hunt-Hess grade (3-5), procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of neurologic morbidity. The procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of mRS score deterioration. CONCLUSIONS: The incidence of SCA (stent-assisted coiling)-related complications with the Atlas stent in this study population was comparable to that in Western populations. We identified the procedure duration and stent length as novel independent predictors of SCA-related ischaemic stroke, neurological morbidity, and mRS score deterioration among the Chinese population.

Comparison of the safety and efficacy of Neuroform Atlas stent deployed via Gateway balloon catheter and microcatheter for the treatment of intracranial stenosis.

OBJECTIVE: This study aimed to compare the safety and efficacy of the Atlas stent released by the Gateway catheter and microcatheter in the treatment of intracranial stenosis (IS). METHODS: The primary efficacy and safety outcomes were the in-stent restenosis (ISR) rate and post-procedural stroke or death within one month. RESULTS: Atlas stents were deployed using the Gateway catheter and microcatheter in 19 (57.6 %) and 14 (42.4 %) procedures, respectively. Follow-up imaging data were available for 26 patients; the incidence of ISR was 15.4 %, and the ISR rate was higher, though not significantly, in the microcatheter group than in the Gateway group (30.0% vs. 6.25 %, P = .39). Clinical follow-up data were available for 30 patients; the post-procedural stroke rate was 3.3 % within one month and 13.3 % from one month to one year. The post-procedural stroke rate within one month was higher, though not significantly, in the microcatheter group than in the Gateway group (7.7% vs. 0 %, P = .43). The Gateway group had a significantly lower rate of post-procedural stroke in the same territory than that of the microcatheter group (0% vs. 30.8 %, P = .026). A higher incidence of residual stenosis <30 % was found in the non-ISR group than in the ISR group (72.2% vs. 0 %, P = .014). CONCLUSIONS: This study provides preliminary evidence that the Atlas stent is safe and effective for IS treatment. The use of the Gateway catheter to deliver the Atlas stent appears to be safer than using microcatheter. The incidence of ISR may be related to the degree of the residual stenosis.

[Clinical application of Neuroform Atlas stent-assisted coiling in the treatment of unruptured wide-neck intracranial aneurysms].

OBJECTIVE: To assess the safety and efficacy of Neuroform Atlas stent used in treatment of unruptured wide-neck intracranial aneurysms. METHODS: Clinical data of 62 patients with unruptured wide-neck intracranial aneurysms undergoing Neuroform Atlas stent-assisted coiling from August 2020 to September 2021 were retrospectively analyzed. There were 64 aneurysms in those 62 patients. Among them, 25 aneurysms were located at the bifurcation of M1 segment on middle cerebral artery, 16 at the anterior communicating artery, 10 at the C7 segment of internal carotid artery, 5 at the C6 segment of internal carotid artery, 4 at the apex of basilar artery, 3 at the A3 segment of anterior cerebral artery, and 1 at the M2 segment of middle cerebral artery. All the patients underwent Neuroform Atlas stent-assisted coiling, including 49 patients with single stent assisted coiling and 15 patients with dual stents assisted coiling (14"Y"style and 1"X"style). After the procedure, the immediate DSA was performed to evaluate the status of aneurysm occlusion and the parent artery patency. The clinical follow-up was performed 3 months after the operation and evaluated based on the modified Rankin Scale(mRS).DSA image was reviewed at 6 months after operation and Raymond grading scale was used to assess the status of aneurysm occlusion and the parent artery patency. RESULTS: A total of 62 patients with 64 aneurysms were all achieved technical success(100%).The immediate post-procedural Raymond scale was assessed, including Raymond Ⅰ in 57 aneurysms(89.1%, 57/64), Raymond Ⅱ in 6 aneurysms(9.3%, 6/64) and Raymond Ⅲ in 1 aneurysm(1.6%, 1/64). The peri-procedural complications rate was 4.8%(3/62), 2 patients developed intraoperative thrombosis and 1 patient suffered from local subarachnoid hemorrhage. Among them, 55 patients obtained 3 months clinical follow-up after operation and all the patients had good outcomes (mRS≤2), 50 patients with 52 aneurysms were followed up with DSA 6 months after operation, including Raymond Ⅰ in 45 aneurysms(86.5%, 45/52), Raymond Ⅱ in 4 aneurysms(7.7%, 4/52) and Raymond Ⅲ in 3 aneurysms(5.8%, 3/52). CONCLUSION: Neuroform Atlas stent for the treatment of unruptured wide-neck intracranial aneurysms has high safety and good efficacy, and has its advantages over other traditional stents.

Initial multicentre experience using the neuroform atlas stent for the treatment of un-ruptured saccular cerebral aneurysms.

Purpose: The Neuroform Atlas is a self-expandable and low-profiled stent that is used for aneurysm neck scaffolding and has been recently approved for clinical practice in Korea. We present our initial experiences of endovascular coiling using the Neuroform Atlas stent.Materials and methods: All cerebral aneurysms treated by stent-assisted coiling with a Neuroform atlas stent in two institutions between February and May 2018 were retrospectively evaluated. Fifty-one patients with 55 un-ruptured saccular cerebral aneurysms (mean size: 4.72 ± 1.81 mm, mean neck diameter: 3.82 ± 1.23 mm, mean dome-to-neck ratio: 1.21) were included in our study (40 females, mean age: 59.29 ± 11.96 years). Patient demographics, aneurysm characteristics, initial angiographic post procedural outcomes, and clinical and angiographic follow-up data were analysed.Results: There was one case of procedural failure due to a downward slip during stent deployment. The technical success rate was 98.2% (54/55). A post-procedure control angiogram showed complete occlusion in 27 (50%), residual neck in 16 (29.6%) and residual sac in 11 (20.4%) aneurysms. There were no procedure-related complications. In one case, a symptomatic thromboembolism with left hand grip weakness (grade IV) was observed two days after the procedure and resolved at discharge. The modified Rankin scale score at discharge was 0 in all patients. Angiographic follow-up data at a mean of 4.8 months were available for 51/54 (94.4%) aneurysms. Among them, 27 aneurysms (52.9%) were stable, 20 aneurysms (39.2%) showed progressive occlusion and 4 aneurysms showed an increased modified Raymond Roy occlusion classification score (only one of these patients was included in the recanalization criteria).Conclusion: Our findings suggest the Neuroform Atlas stent can be useful for the coiling of cerebral aneurysms without significant complications regardless of aneurysm location.

The low-profile Neuroform Atlas stent in the treatment of wide-necked intracranial aneurysms - immediate and midterm results: An Italian multicenter registry.

BACKGROUND AND PURPOSE: Wide-necked brain aneurysms therapy remains a challenge for neurointerventionalists, mainly for the high recurrence rate. Low-profile stents make feasible the treatment of these aneurysms. In our multicenter series we analyzed clinical and angiographic results of Neuroform Atlas stent-assisted coiling. MATERIALS AND METHODS: From January 2016 to March 2017, 113 wide-necked aneurysms were discovered with CTA, MRA and DSA. The Atlas stent-assisted coiling procedures were performed under general anesthesia with sequential or jailing techniques. Six months follow-up DSA was performed to assess the recurrence rate through the modified Raymond-Roy occlusion scale (RROC). Moreover, patients were evaluated clinically to analyse the degree of disability according to the mRS. MRI was performed at 12 months evaluating both the cerebral tissue and the vessels. RESULTS: In all the procedures it was feasible to navigate the Neuroform Atlas to the goal vessel and deploy the stent across the aneurysmal neck. Intra-procedural complications account for the 6.2% (7/113). The immediate occlusion rate was RROC 1 in 88%, 2 in 9% and 3 in 3% of cases. The 6 months clinical data showed mRS Score 0-1 in 96.5% of patients; 3 patients died of complications related to SAH. The 12 months follow-up showed RROC of 1 in 82%, 2 in 13% and 3 in 5% of cases. No aneurysm has been retreated. CONCLUSIONS: In our multicenter experience the Neuroform Atlas stent assisted-coiling has shown to be a safe and effective technique for the treatment of wide-necked intracranial aneurysms with encouraging clinical and angiographic results.

The white-collar sign after Neuroform Atlas stent-assisted coil embolization of unruptured intracranial aneurysms.

PURPOSE: Although stent-assisted technique is expected to help provide a scaffold for neointima formation at the orifice of the aneurysm, not all aneurysms treated with stent-assisted technique develop complete neointima formation. The white-collar sign (WCS) indicates neointimal tissue formation at the aneurysm neck that prevents aneurysm recanalization. The aim of this study was to explore factors related to WCS appearance after stent-assisted coil embolization of unruptured intracranial aneurysms (UIAs). METHODS: A total of 59 UIAs treated with a Neuroform Atlas stent were retrospectively analyzed. The WCS was identified on digital subtraction angiography (DSA) 1 year after coil embolization. The cohort was divided into WCS-positive and WCS-negative groups, and possible predictors of the WCS were explored using logistic regression analysis. RESULTS: The WCS appeared in 20 aneurysms (33.9%). In the WCS-positive group, neck size was significantly smaller (4.2 (interquartile range (IQR): 3.8-4.6) versus 5.4 (IQR: 4.2-6.8) mm, p = .006), the VER was significantly higher (31.8% (IQR: 28.6%-38.4%) versus 27.6% (IQR: 23.6%-33.8%), p = .02), and the rate of RROC class 1 immediately after treatment was significantly higher (70% vs 20.5%, p < .001) than in the WCS-negative group. On multivariate analysis, neck size (odds ratio (OR): 0.542, 95% confidence interval (CI): 0.308-0.954; p = .03) and RROC class 1 immediately after treatment (OR: 6.99, 95% CI: 1.769-27.55; p = .006) were independent predictors of WCS appearance. CONCLUSIONS: Smaller neck size and complete occlusion immediately after treatment were significant factors related to WCS appearance in stent-assisted coil embolization for UIAs using the Neuroform Atlas stent.

Single Neuroform Atlas stent: a reliable approach for treating complex wide-neck bifurcated aneurysms.

Background: Treating wide-neck bifurcated cerebral aneurysms (WNBAs) using various techniques and new devices has shown favorable outcomes. However, endovascular coiling can be technically challenging when the aneurysm neck is incorporated into the parent vessel. Furthermore, although recent research has reported favorable outcomes of Neuroform Atlas stent (NAS)-assisted coiling, broad inclusion criteria have hampered precise evaluations of their effectiveness and safety for treating complex WNBAs. Therefore, this study evaluated whether the use of a single NAS is a safe and effective approach for treating complex WNBAs. Methods: We treated 76 complex WNBAs (unruptured, n = 49; ruptured, n = 27) using single NAS-assisted coil embolization and retrospectively analyzed the clinical and angiographic outcomes. Results: In a cohort of 68 patients (mean age, 58.3 ± 11.6 years; males n = 20, 29.4%; females, n = 48, 70.6%), 76 stents were successfully delivered to the target aneurysms, yielding a technical success rate of 98.6%. Complete occlusion was evident in 59 (77.6%) of 76 aneurysms, with neck remnants found in 16 (21.1%) and partial occlusion in 1 (1.3%). Treatment-related morbidities comprised one branch occlusion and one parenchymal hemorrhage. However, no new neurological symptoms of unruptured aneurysms were evident at discharge. The outcomes of 20 of the 27 ruptured aneurysms were favorable (Glasgow Outcome Scale scores of 4 or 5) at the final follow-up assessment (mean 12.2 [6-29] months), except for one initial subarachnoid hemorrhage. Post-treatment angiography revealed complete occlusion in 89.1%, neck remnants in 7.8%, and incomplete occlusion in 3.1% of the aneurysms. Approximately 88.2% of the patients were assessed at least once by follow-up diagnostic or magnetic resonance angiography (mean, 12.5 ± 4.3 [range, 6-29] months), with five (7.8%) minor and two (3.1%) major recurrences. Conclusion: A single NAS is safe and effective for treating WNBAs incorporated into parent vessels.

Safety and effectiveness of Neuroform Atlas stent-assisted coil embolization for ruptured intracranial aneurysms.

Objective: The treatment outcomes of ruptured intracranial aneurysms using the Neuroform Atlas stent were evaluated. Methods: This study represents a retrospective review that included patients who underwent endovascular treatment for ruptured aneurysms at a single institution. Between January 2018 and September 2022, endovascular treatments including simple coiling or Neuroform Atlas stent-assisted coil embolization were performed in 191 patients with ruptured intracranial aneurysms. Results: Intraprocedural rupture was observed in 11 (8.7%) patients in the Simple Coiling (SC) group, which was slightly higher than that in 4 (6.3%) patients in the Neuroform Atlas stent-assisted coiling (NASAC) group (p=0.241). However, Thromboembolic event (TEE) was slightly more prevalent in the NASAC group, with 4 (6.3%) cases as compared to the 5 (3.9%) cases in the SC group (p=0.235). The retreatment rate was slightly higher in the SC group, with 19 (26.4%) patients as compared to the 10 patients (22.2%) in the NASAC group (p=0.342). Conclusions: The use of the Neuroform Atlas stent (NAS) for ruptured aneurysms might be safe and effective.

Use of the neuroform atlas for stenting of intracranial atherosclerotic disease: Clinical and angiographic outcomes.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is a potential cause of ischemic stroke. Treatment of ICAD can include intracranial stenting. There are specifically designed stents for this use-case; however, less is known about the off-label use of the Neuroform Atlas stent. In this study, we describe the outcomes of the Neuroform Atlas stent for treatment of ICAD. METHODS: Adult patients with symptomatic ICAD failing best medical treatment undergoing elective intracranial stenting using the Neuroform Atlas stent between November 2018 and March 2021 were included. Patient demographics, procedure-related details and clinical and imaging outcomes were analyzed. RESULTS: Eighteen patients met the inclusion criteria, with a mean follow-up duration of 9.6 ± 6.8 (standard deviation) months. There were two procedure-related mortalities (one massive intracranial hemorrhage and one groin site complication with sepsis). Fifteen patients were alive at the 6-month follow-up, all with satisfactory stent patency on follow-up imaging without any new ischemic events. Modified Rankin Scale at latest follow-up was 1.9 (interquartile range 5). CONCLUSION: In this single-center consecutive series, intracranial stenting with the Neuroform Atlas stent was a safe and effective treatment for symptomatic ICAD patients failing best medical management.

A Case of Microguidewire and Neuroform Atlas Stent Entanglement Resulting in Extraction Difficulty.

Objective: The trans-cell technique in stent-assisted coil embolization is a common treatment method for intracranial aneurysm. However, despite the frequency of its use, reports discussing its complications and their management are few. We describe a case of stent and microguidewire entanglement, which could not be removed, during treatment using the trans-cell technique. We discuss the mechanism of the entanglement and its management. Case Presentation: A woman in her 40s was found to have an unruptured cerebral aneurysm with a maximum diameter of 5.9 mm located in the paraclinodal anterior process of the left internal carotid artery during a close examination of a headache. The aneurysm had an irregular shape and wide neck. Stent-assisted coil embolization was planned. Initially, the coil was embolized using a jailing technique, but the microcatheter was pushed out of the aneurysm during embolization. Thus, we attempted to switch to a trans-cell technique. However, during the process, the stent and microguidewire became entangled and could not be removed. Finally, when the stent slipped off, the entanglement was resolved and the microguidewire was retrieved. Fortunately, the patient was discharged home without postoperative complications. Conclusion: Once a stent and a microguidewire become entangled, safely releasing them is difficult. Thus, it is important to avoid this scenario from occurring.

Embolization of unruptured wide-necked aneurysms at the MCA bifurcation using the Neuroform atlas stent-assisted coiling: a two-center retrospective study.

Background: The management of middle cerebral artery (MCA) aneurysms remains a controversial topic, and MCA aneurysms have traditionally been treated primarily by surgical clipping. The Neuroform Atlas Stent™ (NAS, available from Stryker Neurovascular, Fremont, California) represents the latest generation of intracranial stents with improved stent delivery system capabilities. Objective: This study aims to investigate the safety, feasibility and efficacy exhibited by NAS in treating unruptured aneurysms at the MCA bifurcation. Methods: This was a two-center retrospective study involving 42 patients with unruptured wide-necked aneurysms (WNAs) of the MCA treated with the NAS from October 2020 to July 2022. Results: The stent was used to treat 42 cases of unruptured WNA at the MCA bifurcation. Endovascular treatment techniques had a 100% success rate. Immediate postoperative angiography found complete aneurysm occlusion in 34 patients (80.9%) (mRRC 1), neck remnant in 7 patients (16.7%) (mRRC 2), and residual aneurysm in 1 patient (2.4%) (mRRC 3). The thromboembolic complication rate was 2.4% (1/42). The follow-up period was 8.7 months on average (3-16 months). The last angiographic follow-up results revealed complete aneurysm occlusion in 39 patients (92.9%) (mRRC 1), neck remnant in 3 (7.1%) patients (mRRC 2), no aneurysm recanalization or recurrence, and no cases of stent intimal hyperplasia. During the latest clinical follow-up, all patients had an mRS score of 0. Conclusion: Our study demonstrates that the NAS can be applied to treat unruptured WNAs at the MCA bifurcation with favorable safety, feasibility, and efficacy.

Novel technique of stent placement via gateway balloon in intracranial atherosclerosis-associated large vessel occlusion.

BACKGROUND AND PURPOSE: Neuroform Atlas stent can be deployed directly via gateway balloon for angioplasty and stent placement without the need for exchange maneuver required for Wingspan stent use. We present our initial experience of this strategy in intracranial atherosclerosis-associated large vessel occlusions. METHODS: Patients were identified through mechanical thrombectomy (MT) database from January 2020 to June 2022 at our institutions. Due to reocclusion or impending occlusion, rescue angioplasty with stent placement was performed after initial standard MT. Primary outcomes were good angiographic recanalization with modified thrombolysis in cerebral infarction (mTICI) score of 2b-3, rate of intracranial hemorrhage (ICH), and favorable functional outcome at 3 months, that is, modified Rankin Scale (mRS) score of 0-3. RESULTS: We identified 22 patients treated using this technique. Among those, 11 were females with their average age at 66 years (range: 52-85). Initial median National Institute of Health Stroke Scale score was 11 (range: 5-30) and all patients received loading doses of aspirin and P2Y12 inhibitor. After performing submaximal angioplasty and Neuroform Atlas stent deployment through the gateway balloon, we achieved final mTICI of 2b-3 in 20 (90%) patients. One patient had ICH post-op that was asymptomatic. Eight (36%) patients had mRS of 0-3 at 90 days. CONCLUSION: Our preliminary experience suggests possible safety and feasibility of deploying Neuroform Atlas stent through a compatible Gateway balloon microcatheter without the need for ICH-associated microcatheter exchange. Further studies with long-term clinical and angiographic follow-up are warranted to corroborate our initial findings.

Transradial Stent-Assisted Coiling Using "Dual-Jailing" Technique for Kissing Aneurysms of the Internal Carotid Artery: Technical Note and Literature Review.

BACKGROUND: Kissing aneurysms are an unusual type of multiple intracranial aneurysms having different origins with partially adherent walls. Although endovascular treatment is a useful alternative to surgical clipping, endovascular management for small wide-necked kissing aneurysms has not been adequately investigated to date. Herein, we present a case of small wide-necked kissing aneurysms successfully treated with transradial stent-assisted coiling (SAC) using the "dual-jailing" technique. We also performed a review of the relevant literature. CASE PRESENTATION: A 64-year-old woman who was diagnosed with small wide-necked kissing aneurysms relating to the ophthalmic artery underwent SAC using the dual-jailing technique. After a 6F Simmons guiding sheath was delivered into the target common carotid artery via transradial access, a 6F intermediate catheter was navigated into the petrous internal carotid artery to achieve both triple microcatheter manipulation and contrast injection. Two coil-delivery microcatheters were cannulated into each aneurysm, followed by a Neuroform Atlas stent deployment over the aneurysm necks via a third stent-delivery microcatheter. By using the jailed microcatheters, SAC of the kissing aneurysms was successfully achieved, preserving the ophthalmic artery. The postprocedural course was uneventful. A follow-up magnetic resonance angiography showed no evidence of recanalization 2 years 3 months post procedure. CONCLUSIONS: The dual-jailing technique may provide simple and time-saving SAC compared with previous reported method. This technique can be a useful treatment option for small wide-necked kissing aneurysms.

Application of the Neuroform Atlas Stent in Intracranial Aneurysms: Current Status.

The Neuroform Atlas stent (NAS) is the successor of the Neuroform EZ stent. The NAS is compatible with a low-profile 0.0165-inch microcatheter and is soft enough to pass through small and highly tortuous vessels. The NAS can be used in treating intracranial aneurysms at almost all locations, and its use is becoming increasingly common. However, there has not yet been a complete review of NAS applications. Therefore, we performed this review, which addresses several aspects of the NAS, mainly including its characteristics, clinical trials of its application in treating aneurysms, deployment techniques for the device, the prognosis and complications of its application in treating aneurysms, and antiplatelet requirements associated with its use. Based on the evidence reviewed here, as well as our experience, we found that the NAS is a promising device for treating intracranial aneurysms, especially complex and distal aneurysms. This stent can also be used as a powerful tool to assist in rescuing coil migration, completing dual-stent reconstruction, and coiling aneurysms via a transcirculation approach. The device may require antiplatelet therapy at a lower dose and over a shorter period than other stents. The deployment of the NAS to assist in aneurysm coiling can yield good clinical outcomes and an acceptable rate of complications. Thus, the NAS is a promising device.

Neuroform atlas stent-assisted coiling of tiny wide-necked intracranial aneurysms.

Objective: To investigate the safety and efficacy of Neuroform Atlas stent-assisted coiling for the treatment of tiny wide-necked intracranial aneurysms and evaluate risk factors associated with procedure-related complications. Methods: We retrospectively examined 46 patients with 46 tiny wide-necked aneurysms who were treated using Atlas stent-assisted coiling at our institution from August 2020 to May 2022. Patient and aneurysm characteristics, procedural details, procedure-related complications, and angiographic and clinical outcomes were analyzed. Results: A total of 10 patients presented with aneurysmal rupture. Atlas stent placement was successful in all patients. Angiography immediately after the procedure showed complete occlusion in 38 patients (82.6%), neck remnant in 7 (15.2%), and partial occlusion in 1 (2.2%). The mean angiographic follow-up was 8.4 months (range, 6-16). At the last follow-up, angiography showed complete occlusion in 41 patients (89.1%) and neck remnant in 5 (10.9%). No aneurysm recurrence or in-stent stenosis occurred. Incidence of procedure-related complications was 10.8% (intraprocedural aneurysm rupture, two cases; acute thrombosis, two cases; and coil migration, one case); only one patient (2.2%) experienced procedural neurological morbidity. The mean clinical follow-up was 9.7 months. A favorable outcome was achieved in 45 patients (97.8%). In univariate logistic regression analysis, aneurysm size (odds ratio, 4.538; P = 0.045) was significantly associated with procedure-related complications. However, multivariate analysis found no independent risk factors. Conclusion: Atlas stent-assisted coiling of tiny wide-necked intracranial aneurysms is feasible and effective. Outcomes and occlusion rates are favorable and morbidity is low. The complication rate may be higher in larger tiny aneurysms.

Stent-assisted coiling using the Neuroform Atlas stent for treatment of aneurysms that recur after coil embolization.

Objective: To evaluate the safety and efficacy of stent-assisted coiling (SAC) using the Neuroform Atlas stent for aneurysms that recur after coil embolization. Methods: We retrospectively reviewed patients who underwent SAC using the Neuroform Atlas stent to treat aneurysms that recurred after coil embolization from November 2020 to November 2021. Patient and aneurysm characteristics, procedural details, complications, and angiographic and clinical follow-up outcomes were recorded and analyzed. Results: Eleven patients with 11 recurrent aneurysms were included for analysis. Atlas stent deployment was successful in all cases. Angiography immediately after the SAC procedure and at last follow-up showed complete occlusion in 10 patients (90.9%) and a residual neck in one (9.1%). Mean angiographic and clinical follow-ups were 9.2 and 10 months, respectively. A single procedure-related complication occurred, mildly blurred vision in the left eye, which recovered completely. No permanent morbidity or mortality occurred. Conclusion: SAC using the Atlas stent to treat aneurysms that recur after coil embolization is safe and effective. Large-scale studies with long-term follow-up are warranted to confirm our results.

Intentional Stent Herniation Technique Using Neuroform Atlas Stent System for Embolization of a Wide-Necked Basilar Tip Aneurysm.

Objective: Endovascular treatment for complex wide-necked basilar tip aneurysms is challenging. Multiple stenting may be an option to deal with such aneurysms; however, the risk of ischemic complications is reported to be relatively high. Here, we report a case of unruptured basilar tip aneurysm treated using the intentional stent herniation technique to preserve the aneurysmal neck branches. Case Presentation: A 65-year-old woman presented with a growing unruptured basilar tip aneurysm associated with bilateral posterior cerebral arteries (PCAs) arising from the aneurysmal dome. We intentionally selected a large-sized Neuroform Atlas stent (Stryker, Kalamazoo, MI, USA) compared to the parent artery and deployed it along the right PCA to the basilar artery. The stent was herniated into the aneurysmal dome near the origin of the left PCA, resulting in the preservation of the left PCA. Successful coil embolization was achieved with acceptable obliteration. Conclusion: The intentional stent herniation technique may be an effective approach to treat complex wide-necked basilar tip aneurysms.

Safety and effect of Neuroform Atlas stent in the treatment of symptomatic intracranial stenosis: A single-center experience.

BACKGROUND: Vascular intracranial stenosis (IS) is a significant cause of acute ischemic stroke (AIS). This single-center study aims to show that symptomatic IS treatment by using the Neuroform Atlas stent (Stryker neurovascular, Kalamazoo, MI, USA) could be effective in reducing vessel stenosis. METHODS: Ten patients affected by AIS or TIA, in the vascular territory of high-grade intracranial atherosclerotic lesions (>70% of vessel stenosis), older than 18-year-old, were treated by implanting a Neuroform Atlas stent (diameter of 4.5mm in 80% and 4mm in 20%). 70% of the patients underwent pre-stenting intracranial angioplasty. RESULTS: Patients were between 54.8 and 83 years old (mean 68.46y ± 8.44y), 70% males and 30% females. At admission, 50% of all patients had an AIS and 50% a TIA. Restoration of the stenotic lumen was obtained after the endovascular procedure. The percentage mean of vascular stenosis was 83.7% ± 6.09% before treatment (t0), 52.2% ± 10.42% at the end of treatment (t1) and 46.2% ± 8.28% at the follow-up (t2). The IS percentage mean reduction between t0 and t1 was 31.5% ± 7.31%, and between t1 and t2 was 6% ± 5.47%, t0 and t2 of 37.5% ± 7.38%. Percentage reduction of IS was highly significant between time t0 and t1 (p = 0.005), and t0 and t2 (p = 0.005), also with a significant reduction between t1 and t2 (p = 0.012). No patient had experienced an increase of the ischemic area in the vascular territory of the target vessel at 3 months from the initial assessment. 10% of patients experienced a 3-months negative outcome (mRS = 5), 90% experienced a favorable outcome (mRS ≤2). CONCLUSIONS: Intracranial stenosis endovascular treatment with Neuroform Atlas stent provides encouraging results, with a statistically significant association between the vascular caliber improvement and the endovascular treatment.

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.

Optimum concentration of iodine contrast agent injection for best stent visualization using Neuroform Atlas stent during stent-assisted coil embolization: Case reviews based on in vitro experiments.

BACKGROUND: The present study aimed to evaluate the influence of contrast agent concentration (Conc) on the visibility of Neuroform Atlas in vitro and in clinical cases. METHODS: A plastic tube was filled with several Conc. in saline (experiment 1) and blood (experiment 2). Thereafter, the Neuroform Atlas was placed around the plastic tube in an acrylic shield case. In experiment 3, the Neuroform Atlas was placed in the internal carotid artery of the endo vascular evaluator endovascular training system with an injection of several Conc in saline. Five slices of the axial images obtained using the 3D-cone-beam computed tomography (3D-CBCT) with the digital subtraction angiography system were evaluated. A 1-cm2 circular center, which showed the contrast agent in saline or blood, was determined as the region of interest, and its pixels were evaluated. RESULTS: Radiation density (Rd) was directly proportional to the contrast agent in saline and blood (experiment 1: (Rd (pixel)) = 6.8495 × (concentration (%)) + 152.72 (R2 = 0.99), experiment 2: (Rd (pixel)) = 6.2485 × (concentration (%)) + 167.42 (R2 = 0.9966), experiment 3: (Rd (pixel)) = 10.287 × (concentration (%)) + 108.26 (R2 = 0.993)]. Rd calculated similarly in our cases (concentration varied from 5% to 8%) was between the range of "Rd of experiment 2" and "Rd of experiment 3." CONCLUSION: Based on our in vitro experiments, with 5-8% concentration, Neuroform Atlas stent deployment with complete neck coverage by the bulging stent and wall apposition was visualized on 3D-CBCT.