Preliminary experience of stent salvage using Neuroform Atlas stent for procedure-related complication during coil embolization of intracranial aneurysms

Comparative analysis of long term effectiveness of Neuroform Atlas stent versus low profile visualized intraluminal stent/Woven EndoBridge devices in treatment of wide necked intracranial aneurysms

BACKGROUND

We compared the outcomes of wide necked aneurysms (WNA) treated with the Neuroform Atlas with those treated with the low profile visualized intraluminal stent (LVIS) or the Woven EndoBridge (WEB).

METHODS

Objective, prospectively collected, core laboratory adjudicated data from published trials for the Neuroform Atlas, LVIS, and WEB devices were reviewed. ATLAS (Safety and Effectiveness of the Treatment of Wide Neck, Saccular Intracranial Aneurysms With the Neuroform Atlas Stent System) study patients were included if they met other studies' inclusion criteria. Outcomes included (1) primary effectiveness (complete aneurysmal occlusion without retreatment/>50% parent vessel stenosis), (2) primary safety, (3) complete aneurysmal occlusion, and (4) retreatment rates (outcomes evaluated at the 12 month follow-up). Matching adjusted indirect comparison analysis was used to compare outcomes.

RESULTS

Analytical samples included 141 ATLAS subjects meeting WEB-IT (Woven EndoBridge Intrasaccular Therapy Study) criteria (ATLAS/WEB-IT) and 241 meeting LVIS (Pivotal Study of the Low Profile Visualized Intraluminal Support) criteria (ATLAS/LVIS). ATLAS/WEB-IT exhibited significantly higher rates of primary effectiveness and complete occlusion versus WEB (86.6% vs 53.9 %, P<0.0001, and 90.3% vs 53.9%, P<0.0001, respectively). For LVIS, there was no significant differences in primary effectiveness rates between ATLAS and LVIS (84.2% vs 77.7%, respectively, P=0.12). However, ATLAS/LVIS had a significantly higher proportion of patients achieving complete occlusion than LVIS (88.1 vs 79.1, P=0.03). Retreatment rates and primary safety outcomes were not significantly different (P>0.05) for the Atlas versus other devices except for a lower retreatment rate for ATLAS/WEB-IT versus WEB-IT (2.4% vs 9.8%, P=0.01).

CONCLUSION

The Neuroform Atlas provided higher occlusion rates and similar retreatment rates in comparable datasets compared with LVIS and WEB devices when treating WNA.

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.

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.

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.

Outcomes of Stent-Assisted Coiling Using the Neuroform Atlas Stent in Unruptured Wide-Necked Intracranial Aneurysms

Objective

Although stent-assisted coiling (SAC) has been reported to be safe and effective in treating wide-necked aneurysms, the technique has procedure-related complications. Thus, we reported our experiences of SAC using the Neuroform Atlas stent in treating wide-necked aneurysms and evaluated the incidence of and risk factors for procedure-related complications.

Methods

From March 2018 to August 2019, we treated 130 unruptured wide-necked aneurysms in 123 patients with Neuroform Atlas stents. Angiographic results and clinical outcomes were reviewed retrospectively. Clinical and angiographic follow-up were performed in all cases (mean, 12.4 months) after the procedure.

Results

There were eight cases (6.2%) of procedure-related complications (two dissections, five thromboembolisms, and one hemorrhage) and two (1.5%) of delayed complications (one ischemia and one hemorrhage). There was one case (0.8%) of failure of stent deployment and one (0.8%) of suboptimal positioning of the stent. Follow-up angiography showed complete obliteration in 103 (79.2%), residual neck in 16 (12.3%), and residual aneurysm in 11 cases (8.5%). Aneurysm locations in the middle cerebral artery (odds ratio [OR], 2.211; p=0.046) and the anterior communicating artery (OR, 2.850; p=0.039) were associated with procedure-related complications on univariate analysis. However, no independent risk factor for procedure-related complications was noted in multivariate analysis.

Conclusion

The Neuroform Atlas showed a high rate of technical success. Good clinical and radiographic outcomes in early follow-up suggests that the device is feasible and safe. SAC of aneurysms on the middle cerebral artery or anterior communicating artery may require more attention to prevent possible procedure-related complications.