Intrasaccular Flow Disruptor-Assisted Coiling of Intracranial Aneurysms Using the Novel Contour Neurovascular Systems and NEQSTENT: A Single-Center Safety and Feasibility Study

Neqstent coil-assisted flow diverter (NQS) for the treatment of bifurcation aneurysms: the coil-assisted flow diversion safety and performance study (CAFI)

BackgroundThe Neqstent coil-assisted flow diverter (NQS) is a neck bridging device to facilitate coil occlusion of intracranial aneurysms. CAFI is a prospective, single-arm, multicenter study on the safety and performance of the NQS adjunctive therapy device together with platinum coils for treatment of unruptured intracranial aneurysms.

METHODS

Thirty-eight patients were enrolled. Primary endpoints were occlusion at 6 months for efficacy, and any major stroke or non-accidental death up to 30 days or major disabling stroke within 6 months for safety. Secondary endpoints were re-treatment rate, procedure time, and procedure/device-related adverse events. Procedural and follow-up imaging was reviewed by an independent core laboratory. Adverse events were reviewed and adjudicated by a clinical events committee.

RESULTS

The NQS was successfully implanted in 36/38 aneurysms, 2/38 in the intention-to-treat group did not receive a NQS and were excluded from follow-up after 30 days. In the per protocol group (PP), 33/36 patients were available for angiographic follow-up. Device related adverse events were recorded in 4/38 (10.5%) patients, one hemorrhagic and three thromboembolic. In the PP group, immediate post-treatment adequate occlusion (RR1 and RR2) was seen in 9/36 (25%) and progressed to 28/36 (77.8%) at 6 months. Complete occlusion (RR1) was achieved in 29/36 (80.6%) at the last available angiogram (3/36 were post procedure). The mean procedure time was 129 min (50-300 min, median 120 min).

CONCLUSION

The NQS in conjunction with coils appears to be effective in the treatment of intracranial wide-neck bifurcation aneurysms, but its safety remains to be proved in larger series.

TRIAL REGISTRATION NUMBER

NCT04187573.

Large Single-Center Experience with Short-Term Follow-up of Neqstent-Assisted Coiling

BACKGROUND AND PURPOSE

Endovascular treatment of wide-neck bifurcation aneurysms has historically proved difficult with variable outcomes. Different endovascular techniques such as balloon-assisted coiling, stent-assisted coiling, or intrasaccular devices provide a varied range of efficacy and safety. Neqstent-assisted coiling is a new device and technique that aim to provide a maximum of both. We analyzed the early clinical and radiologic outcomes after the use of this new technique and device in our practice.

MATERIALS AND METHODS

This study was a retrospective analysis of ruptured and unruptured intracranial aneurysms treated with the Neqstent. The primary radiologic outcomes were quantified on DSA, CTA, or MRA using the modified Raymond-Roy criteria. The outcomes were defined as immediate complete occlusion (modified Raymond-Roy criteria 1) and complete (modified Raymond-Roy criteria 1) and adequate occlusion (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2) at 6 months posttreatment. The primary safety outcome was the rate of device-related adverse events. Secondary safety outcomes included time to discharge and change in the mRS score at 6-month follow-up.

RESULTS

Twenty patients were treated with the Neqstent from November 2020 to January 2023. Nine had unruptured aneurysms, and 11 were patients with subarachnoid haemorrhage due to ruptured aneurysms. Eighteen of 20 aneurysms (90%) treated demonstrated complete occlusion (modified Raymond-Roy criteria 1) on immediate postembolization angiograms. Sixteen of 17 aneurysms treated (94.1%) remained adequately occluded on 6-month follow-up (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2). Immediate postoperative complications occurred in 2 patients; only 1 patient had residual neurologic deficits at 6 months (mRS = 2).

CONCLUSIONS

Management of large, wide-neck aneurysms remains difficult, with high rates of recurrence and complications. The use of the Neqstent shows promising short-term results for the treatment of complex wide-neck aneurysms. Initial complication rates for our cohort were relatively high. However, this result is likely related to the initial learning experience of device deployment and the use of antiplatelets.

Evaluating Efficacy and Complications of Contour Intrasaccular Device in Cerebral Aneurysm Management: A Multicenter Analysis

BACKGROUND

Intrasaccular devices provide a method for treating complex aneurysms without leaving metallic materials in the parent artery. Compared to other well-studied devices in neurointervention, the Contour device is relatively new as an intrasaccular flow diverter. This study examines its use in cases of incidental aneurysms and its application in the acute treatment of ruptured aneurysms. Additionally, it covers potential complications that may arise and methods for prevention.

METHODS

We conducted a retrospective analysis of 25 patients who underwent treatment with the Contour device at 3 hospital centers. We collected data related to age, gender, baseline modified Rankin Scale, personal habits, medical history, procedure details, and angiographic results according to the Woven endobridge occlusion scale.

RESULTS

A total of 15 patients (65.5%) achieved a satisfactory angiographic result (grade 0-0') 1 year after embolization. Contrast stagnation was observed in 14 patients (58.3%). Intraprocedural complications, such as device displacement, were documented in 3 patients (12%), while 2 patients (8%) had aggregates attached to the device. Regarding late complications, 5 patients (20%) experienced device displacement and 1 patient had a minor stroke (4%). Retreatment was necessary for 3 patients (12%), involving a flow diverter, stenting, and coiling.

CONCLUSIONS

In summary, the Contour device offers a viable option for treating complex aneurysms. While initial results are promising, it is crucial to acknowledge a learning curve to minimize complications and achieve satisfactory angiographic results without the need for additional treatments.

Endovascular treatment of middle cerebral artery aneurysms: current status and future prospects

Middle cerebral artery (MCA) aneurysms are complex and widely distributed throughout the course of the MCA. Various types of aneurysms can occur in the MCA. Ruptured as well as unruptured MCA aneurysms may require treatment to avoid bleeding or rebleeding. Currently, clipping is regarded as the first-line choice for the treatment of MCA aneurysms. However, endovascular treatment (EVT) is emerging as an alternative treatment in selected cases. EVT techniques vary. Therefore, it is necessary to review EVT for MCA aneurysms. In this review, the following issues were discussed: MCA anatomy and anomalies, classifications of MCA aneurysms, the natural history of MCA aneurysms, EVT status and principle, deployments of traditional coiling techniques and flow diverters (FDs), and deployments and prospects of intrasaccular flow disruptors and stent-like devices. According to the review and our experience, traditional coiling EVT is still the preferred therapy for most MCA aneurysms. FD deployment can be used in selective MCA aneurysms. Parent artery occlusion (PAO) can be used to treat distal MCA aneurysms. In addition, new devices can be used to treat MCA aneurysms, such as intrasaccular flow disruptors and stent-like devices. In general, EVT is gaining popularity as an alternative treatment option; however, there is still a lack of evidence regarding EVT, and longer-term data are not currently available for most EVT devices.

In vitro and in silico assessment of flow modulation after deploying the Contour Neurovascular System in intracranial aneurysm models

BACKGROUND

The novel Contour Neurovascular System (Contour) has been reported to be efficient and safe for the treatment of intracranial, wide-necked bifurcation aneurysms. Flow in the aneurysm and posterior cerebral arteries (PCAs) after Contour deployment has not been analyzed in detail yet. However, this information is crucial for predicting aneurysm treatment outcomes.

METHODS

Time-resolved three-dimensional velocity maps in 14 combinations of patient-based basilar tip aneurysm models with and without Contour devices (sizes between 5 and 14 mm) were analyzed using four-dimensionsal (4D) flow MRI and numerical/image-based flow simulations. A complex virtual processing pipeline was developed to mimic the experimental shape and position of the Contour together with the simulations.

RESULTS

On average, the Contour significantly reduced intra-aneurysmal flow velocity by 67% (mean w/ = 0.03m/s; mean w/o = 0.12m/s; p-value=0.002), and the time-averaged wall shear stress by more than 87% (mean w/ = 0.17Pa; mean w/o = 1.35Pa; p-value=0.002), as observed by numerical simulations. Furthermore, a significant reduction in flow (P<0.01) was confirmed by the neck inflow rate, kinetic energy, and inflow concentration index after Contour deployment. Notably, device size has a stronger effect on reducing flow than device positioning. However, positioning affected flow in the PCAs, while being robust in effectively reducing flow.

CONCLUSIONS

This study showed the high efficacy of the Contour device in reducing flow within aneurysms regardless of the exact position. However, we observed an effect on the flow in PCAs, which needs to be investigated further.

Endovascular treatment of wide-necked intracranial aneurysms using the Nautilus Intrasaccular System: initial case series of 41 patients at a single center

BACKGROUND

Endovascular treatment of intracranial wide-necked and bifurcation aneurysms (WNBA) is technically challenging. The Nautilus Intrasaccular System is designed to provide a mechanical barrier at the aneurysm neck to support coil embolization. We report the results of a single-center series of patients treated for intracranial aneurysms with the Nautilus.

METHODS

Clinical and radiological data were retrospectively collected for all patients treated with the Nautilus for an unruptured or ruptured intracranial aneurysm at our center between March 2021 and March 2022. Clinical outcomes (modified Rankin Scale (mRS) scores), Raymond-Roy angiographic occlusion, recanalization, and complications were measured immediately post-procedure and at 3-6-month follow-up.

RESULTS

A total of 41 patients of mean age 56.7 years (range 37-83 years) were treated with the Nautilus, with 41 saccular aneurysms (18 (43.9%) unruptured and 23 (56.1%) ruptured). The majority of aneurysms (39/41 (95.1%)) were located in the anterior circulation. We experienced no technical complications. One patient had an asymptomatic post-procedural minor stroke related to the procedure. Immediate Class I occlusion was achieved in 30 (73.1%) patients. The rate of all-cause mortality was 7.3% (3/41). One patient was lost to follow-up. At follow-up, 94.5% (35/37) of patients achieved Class I occlusion and 94.5% (35/37) had an mRS score of 0. There were no procedural-related deaths or permanent morbidities at discharge or follow-up.

CONCLUSION

This study demonstrates good safety and effectiveness using the Nautilus Intrasaccular System to treat both ruptured and unruptured intracranial aneurysms. Larger studies are needed to confirm these findings.

Rescue stenting after artery occlusion as a complication of an intrasaccular device-assisted coiling embolization: illustrative case

BACKGROUND

Endovascular embolization of wide-necked aneurysms can be challenging. The development of intrasaccular devices like the Contour has enabled us to approach these aneurysms effectively by reducing recanalization rates and eliminating the need for dual antiplatelet therapy, which is particularly beneficial in the case of ruptured aneurysms. Although complications from using these devices are rare, it is crucial to address them properly. In this case, the authors highlight how to manage artery thrombosis caused by device protrusion during aneurysm embolization.

OBSERVATIONS

This report describes a complication in a male patient with a ruptured anterior communicating artery wide-necked aneurysm. Following Contour-assisted coiling of the aneurysm, a realignment of the detachable apex of the device occluded the A2 segment of the right anterior cerebral artery. After the failure of intra-arterial and intravenous tirofiban infusion as well as mechanical thrombectomy, a self-expanding open-cell stent was deployed in the involved vessel, achieving successful reperfusion.

LESSONS

The Contour device has a detachable zone that can cause occlusion of the parent vessel after deployment. The use of a stent as a rescue maneuver may be useful if reperfusion of the vessel cannot be achieved through other methods such as aspiration or full-dose antiplatelet therapy.

A review and journey in intrasaccular treatment of intracranial aneurysms

The invested effort and collaboration of clinicians and medical device companies to improve occlusion rates and clinical outcomes for patients with intracranial aneurysms treated via less invasive endovascular means led to the development of the concept of intrasaccular devices. Intrasaccular devices were introduced to offer simple treatment options, offering easier navigation through difficult anatomy, simpler and quicker deployment into large and wide-neck aneurysms. Additionally, they offer easier sizing, whilst offering a wide range of options suitable for aneurysms of different sizes. The concept of most intrasaccular devices is to occupy the aneurysm neck, however offering better stability than simple coiling, therefore increasing the chance of long-term aneurysm occlusion. This is achieved without a sizable metal content within the parent vessel, contrary to flow diverters, theoretically reducing the risk of thromboembolic events. This review aims to discuss the history and latest developments of intrasaccular intracranial devices, which offer an exciting and potentially successful option for treatment of complex intracranial aneurysms.

The safety and effectiveness of the Contour Neurovascular System for the treatment of wide-necked aneurysms: A systematic review and meta-analysis of early experience

BACKGROUND

The Contour is a new generation intrasaccular flow disruption tool that aims to cover the aneurysm neck and is sized according to the neck diameter. While several case series have been published, no literature review has been performed on this promising device.

OBJECTIVE

To assess the safety and effectiveness profile of the Contour Neurovascular System for wide-necked aneurysms.

METHODS

We followed the recommendations of the PRISMA checklist Four databases were searched with a supplemental manual search. All data were analyzed using R software version 4.2.1.

RESULTS

We finally included six studies with 131 treated aneurysms. The overall procedural time was 97.27 (95% CI = 70.07-124.47) minutes, ranging from 78.9 to 136.0 min. The pooled adequate occlusion rate was 84.21% (95% CI = 75.45-90.25), and the overall functional independence rate was 94.74% (87.97-97.79). The overall adverse event rate was 4.70 (95% CI = 3.24-6.76), varying among different events from 0.78 to 8.53%. Thromboembolic events were the most commonly encountered in 8.53% of the patients (95% CI = 4.78-14.74), followed by headache and minor stroke with incidence rates of 5.88 (95% CI = 2.83-11.83) and 4.35 (95% CI = 1.41-12.63), respectively. The overall procedural time in studies using the Contour system only was 86.17 (95% CI = 68.70-10.64) minutes, while it was 136 (95% CI = 90.96-181.04) in the Contour-assisted coiling procedures. However, both techniques were comparable regarding adequate occlusion rates and functional independence.

CONCLUSION

With the anticipation of future studies, the Contour Neurovascular System is a safe and effective treatment option for wide-necked intracranial aneurysms.