Neuroform Atlas Research Articles

Rescue Stenting Using Neuroform Atlas Stent During Coiling Protrusion for Ruptured Intracranial Aneurysms

Endovascular coiling is generally considered as an effective treatment option for ruptured intracranial aneurysms. Increasing operator experience and quality of tools determined an improvement of endovascular cerebral aneurysms' treatment. However, procedure-related complications still occur. The purpose of this study is to report a series of rescue stenting procedures with the Neuroform Atlas (NA) open-cell stent, for intraprocedural complications during coil embolization in patients with ruptured intracranial aneurysms. Between April 2016 and January 2018, 12 consecutive coil protrusions that occurred during ruptured aneurysms' embolizations were rescued using NA stenting together with tirofiban therapy. Follow-up was performed with initial magnetic resonance angiography (MRA) at 1 month and then MRA plus standard digital subtraction angiography at 11-13 months after the procedure. Technical success was achieved in 100% of patients. No NA stent delivery/deployment complication occurred. Initial MRA showed complete occlusion of the aneurysm, with evidence of blood flow into parent vessels in 12 out of 12 cases. At 11-13 months, MRA and digital subtraction angiography showed 10 complete occlusion cases and 1 partial occlusion case. At 2 months, 1 death occurred due to subarachnoid hemorrhage. The open-cell NA stent represents a rescue option for coil protrusion during endovascular treatment of ruptured intracranial aneurysms allowing regular restoration of blood flow and minimizing thromboembolic events.

Low-Profile Neuroform Atlas Stent-Assisted Coiling of Intracranial Aneurysms: Single-Center Initial Experience

Abstract Background Neuroform Atlas stent is a relatively new device used for stent-assisted coiling (SAC) of wide-necked intracranial aneurysms. Purpose To elaborate the initial experience in a single center to assess the efficacy and initial results of Neuroform Atlas for SAC of intracranial aneurysms. Methods Between February 2017 and September 2018, eight patients (five females, three males; mean age 56 years) underwent SAC with Neuroform Atlas. Results Five unruptured and three ruptured wide-necked aneurysms were treated with Neuroform Atlas SAC. Immediate complete occlusion modified Roy-Raymond class 1 (MRRC 1) or mild neck residue class 2 (MRRC 2) was achieved in three patients and five other patients had minimal residual interstitial filling of the aneurysm (MRRC 3b). One patient with ruptured intracranial aneurysm succumbed to the illness in the first postoperative day due to massive rebleed. Other seven patients remained clinically asymptomatic in the follow-up period. Patent stent was noted at three to seven months follow-up magnetic resonance angiography (MRA) in five patients. Complete occlusion of the aneurysm was noted in three patients, and minimal residual aneurysm was seen in two patients. Conclusion Neuroform Atlas stent is safe and effective in achieving good angiographic outcome in complex intracranial aneurysms.

Early post-Humanitarian Device Exemption experience with the Neuroform Atlas stent

IntroductionThe low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with...

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

Background and purposeWide-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 methodsFrom 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. ResultsIn 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. ConclusionsIn 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.

Initial experience and one-year follow-up with Neuroform Atlas Stent System for the treatment of brain aneurysms.

The Neuroform Atlas Stent System is a recently introduced modification of the original Neuroform Stent System consisting of a hybrid design with open and closed cells. Initial experience, technical considerations and treatment outcomes including 1-year follow-up using the Atlas stent in combination with coil embolization are reported. Thirty patients with 30 unruptured aneurysms were treated with stent reconstruction. Immediate, 4-month and 12-month post-treatment angiography and clinical assessment were performed. In 29 cases, the stents were delivered and positioned without difficulty in deployment. Technical complications occurred in one patient related to advancement of the stent during delivery. One procedure-related clinical complication occurred with no permanent neurological deficit. On immediate post-treatment angiography, 29 of 30 aneurysms showed Raymond Class I or Class II occlusion. At 1-year follow-up, all 30 patients were clinically stable and 18 of 30 aneurysms showed Raymond Class I complete occlusion. Retreatment was performed in two patients with residual aneurysm. The Atlas stent is technically safe and simple to implant and has a low thrombogenic potential. We experienced fewer problems associated with deployment and implantation, thromboembolic complications and hemorrhagic events compared with other types of stents, including braided stents. However, because of its low thrombogenic potential, partially occluded aneurysms or those with aneurysm remnants do not progress to complete occlusion.

Neuroform Atlas stent in treatment of iatrogenic dissections of extracranial internal carotid and vertebral arteries: a single-centre experience.

To present our experience in the treatment of iatrogenic dissections of extracranial internal carotid and vertebral arteries with the Neuroform Atlas stent. Between January 2017 and February 2018 we treated iatrogenic dissections of three internal carotid arteries and three vertebral arteries. These iatrogenic dissections occurred during the endovascular treatment of ruptured and unruptured intracranial aneurysms. The indication for stenting was haemodynamically significant, flow-limiting dissection with threatening flow arrest. In all six cases, the dissections were treated by placement of Neuroform Atlas stents in the dissected segments of internal carotid or vertebral arteries. Deployment of the stent was followed by the usual dual antiplatelet regimen. Single or multiple Neuroform Atlas stents were deployed without any technical difficulties, and blood flow was restored immediately after placement of the stents in all six cases. Midterm follow-up (6-8 months) showed complete reconstruction of the shape and lumen of all treated arteries, with negligible intimal hyperplasia. Our results indicate that a favourable outcome can be achieved by treating iatrogenic dissections of extracranial internal carotid and vertebral arteries with the Neuroform Atlas stent.

Abstract WP119: Stent-Assisted Coiling of Intracranial Aneurysms With the Neuroform ATLAS Stent: Immediate and Midterm Angiographic and Clinical Follow-Up

Object: Self-expandable stents have broadened the spectrum of endovascular treatment of intracranial aneurysms. The Neuroform ATLAS, the evolution of Neuroform EZ, is a nitinol self-expanding hybrid/open-cell stent, which can be delivered through a low-profile 0.017 inch catheter. We present our experience in the treatment of intracranial aneurysms with this stent. Methods: We prospectively maintained a database from consecutive patients who underwent stent-assisted coiling with Neuroform ATLAS from July 2015 to July 2018. Clinical and angiographic results were analyzed. Results: Ninety-one patients harboring 95 aneurysms were treated in 95 procedures. A single stent was used in 42 (44.2%) cases, while 52 (54.7%) aneurysms were treated with 2 stents (50 “Y” configuration, 2 “X” configuration). One case of Y stent-assisted coiling was prematurely interrupted because of aneurysm perforation. Post-treatment control angiography showed complete occlusion in 55 cases (58.5%), neck remnant in 15 cases (15.9%), incomplete occlusion in 24 cases (25.5%). The overall symptomatic peri-procedural complication rate was 13.7%. The overall morbidity rate was 4.2% (4 cases with a modified Rankin Scale >2 and <6). The overall mortality rate was 2.1% (2 cases). Fifty-six aneurysms underwent follow-up (mean follow-up: 10.5 months): 47 aneurysms (83.9%) were completely occluded, 7 aneurysms (12.5%) had a neck remnant, and 2 aneurysms (3.6%) was incompletely occluded. Conclusion: The Neuroform ATLAS is an effective device for treatment of complex intracranial aneurysms, allowing good conformability and high level of navigability, but with a non-negligible rate of complications.

Neuroform Atlas Stent System for the treatment of intracranial aneurysm: primary results of the Atlas Humanitarian Device Exemption cohort

Background and objectiveStent-assisted coil embolization is a well-established treatment of intracranial wide-necked aneurysms. The Neuroform Atlas Stent System is a new generation microstent designed to enhance coil support, conformability, deliverability,...

Imaging Parameter Optimization of Non-contrast Three-dimensional Time-of-flight Magnetic Resonance Angiography for Patients with Intracranial Stents Using a 1.5 T Magnetic Resonance Imaging System

The imaging parameters of non-contrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF-MRA) were optimized to improve the image quality for patients treated using stent-assisted coiling. A simulated blood flow phantom with three types of stents (Enterprise 2, Neuroform Atlas, and LVIS) was imaged by changing echo time (TE), band width (BW), flip angle (FA), and matrix (phase, frequency). The difference between the signal intensity in the simulated vessel and the background was measured at each imaging condition. The ratio of this difference with and without the stent was evaluated as the relative in-stent signal (RIS). In addition, the error ratio of the stent lumen diameter was assessed by comparing the full width at half maximum (FWHM) to that measured by 3D X-ray angiography. The RIS was higher in order of LVIS, Neuroform Atlas, and Enterprise 2 in all conditions. The RIS was higher in imaging conditions with short TE, narrow BW, high FA, and large phase matrix. The highest RIS was seen with a frequency matrix of 320 in the Enterprise 2 and 256 in the others. FWHM error ratio was smaller in the same order as the RIS. FWHM error ratio was smaller in imaging conditions with short TE, large frequency matrix (>384), large phase matrix (>224), and high FA (>20°). Imaging conditions of 3D TOF-MRA that were effective to improve the image quality for stent lumen evaluation were short TE and high spatial resolution.

NeuroForm Atlas Stent-Assisted Coiling: Preliminary Results

Stent-assisted coiling (SAC) is increasingly being performed as intervention for wide-neck intracranial aneurysms. The NeuroForm Atlas Stent (CE-marked; Stryker, Kalamazoo, Michigan) is relatively new. To evaluate the effectiveness and safety of NeuroForm Atlas SAC for intracranial aneurysms in the first such study. We retrospectively analyzed data from all patients treated with the NeuroForm Atlas SAC of an intracranial aneurysm, both ruptured and unruptured, between June 2015 and December 2016. Primary end-points were favorable clinical outcomes (modified Rankin scale score 0-2) and successful aneurysm occlusion (Raymond-Roy class I/II), both at 6-mo follow-up. Secondary end-points were the occurrence of intervention-related complications leading to permanent neurological deficit, the occurrence of intervention-related stroke and neurological death, immediate aneurysm occlusion, rupture (or rerupture) of the aneurysm, and recanalization. Twenty-seven consecutive patients, 10 with ruptured saccular wide-neck aneurysms, were treated with NeuroForm Atlas SAC. At 6-mo follow-up, 18/26 (69.2%) survivors had successful aneurysm occlusion and 22/26 (84.6%) had favorable clinical outcome. One patient had died of a cause unrelated to treatment. No intervention-related complications leading to permanent neurological deficit occurred. However, intraprocedural thromboembolic complications occurred in 4/27 patients (14.8%), and ischemic stroke related to treatment occurred in 4/26 (15.4%). No hemorrhagic complications were observed. NeuroForm Atlas SAC is a feasible way to treat ruptured and unruptured wide-neck aneurysms that are not amenable to conventional coiling or clipping. Aneurysm occlusion and favorable clinical outcome are consistent with previously reported rates for SAC of wide-neck aneurysms with other devices.

Visualization of Four Intracranial Stents and In-stent Stenosis with Stenotic Models by 3D-TOF-MRA

In recent years, various types of stents are deployed for the treatment of intracranial artery stenosis and aneurysms. Digital subtraction angiography has been considered to be the gold standard for the follow-up study. However, magnetic resonance angiography (MRA) is less invasive and the recent advances may contribute to the imaging of patients with intracranial stents. Then, a phantom study was carried out to evaluate the MR lumen visibility with these stents. Four stents [low-profile visualized intraluminal support (LVIS), Neuroform Atlas, Neuroform EZ, and Enterprise 2] were placed into plastic tubes with 3 mm inner diameter, and fixed in a container filled with agar. Time-of-flight MRA (TOF-MRA) was performed for these stents, and the signal intensities inside and outside the stents were measured on ImageJ software. Furthermore, 25%, 50%, and 75% stenosis models were created and passed through these stents to evaluate the diagnostic accuracy of in-stent stenosis. The signal intensity inside the LVIS stent was the highest among the four stents (P<0.001), and no significant difference was found between the signal intensities inside and outside the LVIS stent. The diagnostic accuracy with LVIS was also higher than that of Enterprise 2 (P<0.001). In conclusion, the visibility with LVIS indicates that TOF-MRA could be reliably utilized as a diagnostic tool for the detection of in-stent stenosis.

The Neuroform Atlas stent to assist coil embolization of intracranial aneurysms: a multicentre experience

ObjectiveTo assess the clinical safety and efficacy of the Atlas microstent in stent-assisted coil embolization of wide-necked intracranial aneurysms.MethodsSingle-center observational study in 36 patients (24 female, 12 male, mean age...

Stent-assisted coiling of cerebral aneurysms with the Neuroform Atlas stent.

Objectives The Neuroform Atlas stent (AS) is the smallest intracranial stent with an open-cell design. This study reports the first clinical experience with AS. Methods All intracranial aneurysms treated by stent-assisted coiling using a single AS in a single institution were retrospectively evaluated. Patient demographics, aneurysm characteristics, angles between the parent artery and stented branch, technical success, and clinical and angiographic follow-up were analyzed. Results Fifty-five consecutive aneurysms treated with AS-assisted coiling were included. Of these, 69.1% were located distal to the circle of Willis. Technical success rate was 100%. The mean diameters of proximal and distal parent arteries were 2.62 mm (range 1.5-4.4) and 1.8 mm (range 0.8-3.5), respectively. Except for a minor stroke in a patient who completely discontinued antiplatelet therapy on postoperative day 4, there were no clinical events with permanent sequelae, and 94.1% of patients had Raymond-Roy score of 1 or 2 aneurysmal occlusion at a mean follow-up duration of 7.9 months. Although the angle between the parent artery and the stented branch increased significantly ( p < 0.001) with time, the angular change at follow-up was only 16.45 ± 11.03 degrees and was inversely correlated both with preoperative angle and the diameter of the distal parent artery ( r = -0.465 and r = -0.433, respectively, p = 0.004 for both). Conclusion AS-assisted coiling was associated with a favorable early clinical outcome and angiographic results in this series. This stent can be used for distally located aneurysms and results in minimal alteration of the arterial anatomy.

Abstract WP89: Preliminary Single-center Experience with Neuroform Atlas Stent-assisted Coiling for Unruptured Intracranial Aneurysms

Background and Purpose: Expandable stents have broadened the spectrum of endovascular treatment of intracranial aneurysms. The Neuroform ATLAS, a nitinol self-expanding, hybrid/open-cell stent, is the evolution of the Neuroform EZ supposing to ease the navigability of the system into intra-cranial arteries, through a low-profile 0.017 inch delivery catheter. We present herein our initial experience in the treatment of intracranial aneurysms with this stent. Materials and Method: We compiled data from consecutive patients of our institution from July 2015 to June 2016 who underwent stent-assisted coiling with the Neuroform ATLAS. Clinical and angiographic results were analyzed retrospectively. Results: Thirty-six intracranial saccular aneurysms (18 MCA, 10 AcoA, 4 ICA bifurcation, 2 basilar tip, 1 vertebral-PICA, 1 pericallosal artery) in 35 patients (24 women, 11 men, mean age 60 years) were consecutively treated. The stent was used in 32 previously untreated aneurysms, and in 4 cases of recanalization. One single stent was used in 15 aneurysms while 21 aneurysms (58.3%) were treated with 2 stents in a “Y” configuration. The immediate post-treatment angiography showed a complete occlusion in 19 cases (52.7%), a residual neck in 4 cases (11.1%) and a residual aneurysmal contrast filling in 13 cases (36.1%). Two complications occurred (5.5%), the first due to an associated aneurysm perforation (mRs 1), and the second due to parent vessel perforation (mRs 6). Both of them occurred after the stent implantation. We don’t report any case of attempted stenting treatment. Conclusion: The Neuroform ATLAS Delivery System is an effective device for treatment of complex intracranial aneurysms, allowing good conformability and stability with a high level of navigability. The 2 main advantages are its low profile and the cell-design allowing easy mesh crossing to perform Y-stenting procedures. Key words: Neuroform ATLAS, Neuroform EZ, Stent-assisted coiling, cerebral aneurysm. Abbreviations: mRs: modified Rankin Scale, AcoA: Anterior communicating artery, PICA: posterior inferior cerebellar artery.