Real-Time Monitoring of Aneurysm Catheterization During Stent-Assisted Coiling for Irregularly Shaped Intracranial Aneurysms: The Scope Technique

OBJECTIVE

Stent-assisted coiling (SAC) using the jailing technique is a well-established treatment for wide-neck intracranial aneurysms. However, low-volume packing, which is a key factor for aneurysm recanalization, can occur in patients with irregularly shaped aneurysms. We have devised a real-time monitoring system for aneurysm catheterization that allows the intentional placement of the jailed coil-delivery microcatheter and deployed stent, referred to as the "scope" technique. Herein, we present a case of irregularly shaped anterior communicating artery (ACoA) aneurysm successfully treated with SAC using this technique.

METHODS

A 72-year-old woman diagnosed with an unruptured wide-neck ACoA aneurysm that was eccentric to the parent ACoA and overhanging posteriorly underwent SAC using this technique. Bilateral transradial quadraxial systems (6-Fr Simmons guiding sheath/6-Fr intermediate catheter/3.2-Fr intermediate catheter/microcatheter) were established via right and left internal carotid artery. The stent-delivery microcatheter was advanced into the left A2 via the right A1, leaving a 0.014″ microguidewire for visualization under fluoroscopic guidance. To place the coil-delivery microcatheter in the middle of the aneurysm after stent deployment, the coil-delivery microcatheter was cannulated into the aneurysm via the left A1, intendedly through the posterior side of the stent-delivery microcatheter in the down-the-barrel view of the parent ACoA (the scope technique).

RESULTS

After stent deployment, SAC of the aneurysm was successfully achieved.

CONCLUSIONS

Using this technique, the coil-delivery microcatheter was cannulated into the aneurysm, while monitoring its positional relationship with the stent-delivery microcatheter in real time. This technique is a useful treatment option for irregularly shaped and wide-neck aneurysms.

Stent-Assisted Embolization for Acutely Ruptured Aneurysm

Objective

The purpose of this study was to report the results of stent-assisted embolization performed at our hospital for acutely ruptured aneurysms.

Methods

This study consisted of 19 patients (4 men and 15 women) with acutely ruptured wide neck aneurysm who underwent stent-assisted coil embolization in acute stage between December 2016 and October 2020. Stent-assisted embolization in the acute stage was performed for very wide neck ruptured aneurysm only when balloon-assisted embolization was failed or was thought to be impossible. Factors related to poor clinical outcome were examined.

Results

There were nine internal carotid artery (ICA) aneurysms, four anterior communicating artery (AcomA) aneurysms, three basilar artery (BA) aneurysms, two vertebral artery (VA) aneurysms and one anterior cerebral artery (ACA) aneurysm. The stents used were one Neuroform EZ and 18 Neuroform Atlas (Stryker). The contrast of the bleb disappeared in all cases with obvious bleb. Complete obliteration was achieved in two cases, neck remnant was in ten, and body filling was in seven. Both of the complete obliteration cases developed thrombotic complications. Modified Rankin score of 0-2 was observed in eight patients (good clinical outcome), whereas that of 4-6 was observed in 11 patients (poor clinical outcome). Several factors possibly affected to poor clinical outcome were examined and only age over 80 years was statically different. Complications related to procedure occurred in five patients; two cases of in-stent thrombosis, one case each of MCA perforation, stent occlusion, and coil fracture.

Conclusion

Stent-assisted coil embolization using Neuroform EZ and Neuroform Atlas could be considered as an emergency treatment for acutely ruptured cerebral aneurysms with very wide neck. It is rarely indicated in patients with age over 80 years.

Initial Experience of Coil Embolization for Unruptured Intracranial Aneurysm Combined with Neuroform Atlas and Undersized Flexible Coils

Objective

Intraprocedural rupture (IPR) is a rare complication that can occur during endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). However, it leads to high morbidity and mortality rates. Others have showed that coil flexibility is a risk factor for IPR. Neuroform Atlas (NA) stents can be deployed with 0.0165-inch microcatheters to enable stent assisted coiling (SAC) with a high likelihood. Undersized flexible coils can be inserted initially during SAC. This study aimed to determine whether SAC using NA and highly flexible coils for UIAs can be conducted without IPR.

Methods

We retrospectively analyzed nine consecutive patients (mean age, 73.2 years; female, n = 6) who underwent SAC for UIAs combined with NA stents and undersized flexible coils between January 2017 and December 2019. Two aneurysms were located at the internal carotid artery (ICA), and one each was located at the ICA-posterior communicating, anterior communicating, middle cerebral, vertebral, vertebra-posterior inferior cerebral and basilar arteries. The mean size of the aneurysms was 4.6 (range, 3.1-8.6) mm. SAC proceeded using the jailing technique. All coils were selected from among the most flexible coils available. We retrospectively assessed technical success rates, aneurysm occlusion at final digital subtraction angiography (DSA), volume embolization ratios (VERs), rates of IPR and symptomatic stroke within 30 days, angiographic findings of aneurysm occlusion at 3 months post-procedure and late adverse events (frequency of aneurysmal rupture, ipsilateral ischemic stroke, and retreated targeted aneurysms).

Results

The technical success rate was 100%. Complete occlusion (CO) was immediate in 8 (89%) patients and a neck remnant persisted in 1 (11%). No IPR or symptomatic stroke developed within 30 days. During a mean follow-up period of 11.8 months, CO persisted in 8 (89%) patients. No late adverse events occurred.

Conclusion

The early clinical and angiographic findings of SAC for UIAs combined with an NA stent and undersized flexible coils were favorable for this series.

Treatment of Recurrent Aneurysm of the Internal Carotid Artery-poster Communicating Artery Using the Marathon Microcatheter: A Case Report

Objective

We report the case of an aneurysm of the recurrent internal carotid artery (ICA)-posterior communicating artery (PCoA) treated using a liquid embolic delivery microcatheter (MC; Marathon).

Case Presentation

A 66-year-old female previously presented with subarachnoid hemorrhage, which had been treated using coil embolization for a ruptured ICA-PCoA aneurysm. She was referred to our hospital because the aneurysm recurred 13 years after treatment. Angiography revealed a de novo lobulated aneurysm at the ICA-PCoA bifurcation with a relatively thickened PCoA branching from the neck of the aneurysm. We performed coil embolization after stent placement with the Neuroform Atlas in the range of the ICA terminus and the PCoA. However, the coils were unequally distributed and it was necessary to navigate the MC to the aneurysm within the stent through the PCoA. We successfully approached the aneurysm using the Marathon. We additionally inserted six ED coils into the aneurysm and achieved favorable embolization.

Conclusion

The Marathon is useful for passage of a stent deployed in a small-caliber artery.

Stent-Assisted Coiling of Intracranial Aneurysms Using a Nitinol-Based Stent (Neuroform Atlas): A Systematic Review and Meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to synthesize the latest evidence on the efficacy and safety of Neuroform Atlas-assisted coiling of intracranial aneurysms.

METHODS

We performed a comprehensive search for articles that assessed the efficacy and safety of Neuroform Atlas-assisted coiling of intracranial aneurysms. The outcome measurement was adequate occlusion, defined as Raymond-Roy Class I (RR1) + Raymond-Roy Class II (RR2) by previous studies.

RESULTS

A total of 557 patients (568 aneurysms) from 13 studies were included. The rate of adequate occlusion after the procedure was 88% (83-94%, I²: 72.21%), and the rates of RR1 and RR2 were 68% (60-77%, I²: 81.87%) and 21% (15-27%, I²: 66.10%), respectively. The adequate occlusion rate at 6 months was 90% (81-99%, I²: 58.04%) and 93% (91-96%, I²: 0%) at the end of a mean of 9.03 ± 1.03 months of follow-up. Periprocedural complications occurred in 35 patients [5% (3-8%, I²: 21.28%)]. Subgroup analysis of unruptured aneurysms showed that the rates of adequate occlusion were 85% (78-93%), 90% (79-100%) (6-month follow-up), and 93% (90-96%) (at the end of follow-up). For the wide-necked aneurysm subgroup, the rate of adequate occlusion was 86% (80-93%) and was 93% (89-97%) at the end of follow-up. Meta-regression showed that initial adequate occlusion was influenced by mean aneurysm neck size (p = 0.034).

CONCLUSION

Neuroform Atlas-assisted coiling is associated with an initial adequate occlusion rate of 88% and a periprocedural complication rate of 6%. The rate of initial adequate occlusion was 85% in unruptured aneurysms and 86% in wide-necked aneurysms.

LEVEL OF EVIDENCE

Level 2, Systematic review of non-randomized and single-arm studies.

Low-Profile Laser-Cut Stents for Endovascular Treatment of Intracranial Aneurysms : Incidence, Clinical Presentation and Risk Factors of Thromboembolic Events

PURPOSE

Low-profile intracranial stents are characterized by a miniaturized design that enables deployment via a 0.0165″ or 0.017″ internal diameter microcatheter, which is typically intended for coil delivery. This study analyzed the incidence, clinical relevance and risk factors of thromboembolic events (TEE) occurring during low-profile stent-assisted coiling of intracranial aneurysms.

METHODS

This was a retrospective, multicenter analysis of consecutive patients who underwent stent-assisted aneurysm coiling (SAC) with the laser-cut Acandis Acclino and Neuroform Atlas stents. The study evaluated the incidence of symptomatic and asymptomatic TEEs and the impact on functional outcome. Risk factors for TEEs were determined by univariate and bivariate logistic regression analyses.

RESULTS

Among 131 procedures (mean patient age 56.5 ± 12.8 years, mean aneurysm size: 6.7 ± 3.9 mm) TEEs occurred in 14 cases (10.7%) of which 2 patients (1.5%) developed ischemic stroke, while the remaining TEEs remained asymptomatic. Multivariate analysis revealed Y‑stenting as potential risk factor for TEEs (odds ratio: 3.9, 95% confidence interval: 1.0-16.5; p = 0.08).

CONCLUSION

The use of SAC with low-profile intracranial stents is associated with a favorable safety profile; however, Y‑stenting may carry an increased risk of TEEs, which needs to be considered during treatment planning.

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

OBJECTIVES

Although stent-salvage technique has been well-known to rescue the situation of coil protrusion into the parent artery aggravating to make thromboembolism, the smallest profiled Neuroform Atlas stent can be expected to handle those situations easily compared to previously used intracranial stents. Thus, the purpose of this study was to report our series of stent salvage using the Neuroform Atlas stent for procedure-related complications during coil embolization of intracranial aneurysms.

PATIENTS AND METHODS

In March 2018, the Neuroform Atlas was approved for use in our country. Since then, we have treated 541 aneurysms in 502 patients with coil embolization. There were 15 consecutive cases (14 unruptured and 1 ruptured) with procedure-related complications, such as coil protrusion or parent artery thrombosis, rescued by the Neuroform Atlas stent. Follow-up angiography was performed in 14 of the 15 patients between 6-12 months (mean 8.2 months) after the procedure, and clinical follow-up was performed from 2 to 18 months (mean 11.2 months) after the procedure.

RESULTS

Procedure-related complications included parent artery thrombosis due to coil herniation (n = 5) and coil protrusion floating in the parent artery (n = 10). There was no complication related to delivery or deploy of Neuroform Atlas stents. In 12 (80.0 %) of the 15 cases, the stent was deployed via the same microcatheter for coil delivery. In 3 cases of wide neck aneurysms, the stent was deployed via another microcatheter per the scheduled stent-assisted or double microcatheter techniques. Initial angiographic results showed 11 (73.3 %, 11/15) cases of complete occlusion, and 12 (85.7 %, 12/14) cases achieved complete occlusion in follow-up angiographies.

CONCLUSIONS

Facing with procedure-related complications during coil embolization of intracranial aneurysms, the smallest profiled Neuroform Atlas stent might be a time-saving and feasible option for the salvage technique by using the same microcatheter to deliver coils.