Endovascular Treatment of Wide-Neck Bifurcation Aneurysm: Recent Trends in Coil Embolization with Adjunctive Technique

Wide-neck bifurcation aneurysms (WNBAs) are sometimes challenging to treat. During endovascular treatment, it is important to prevent coil deviation and preserve normal vessels. Adjunctive balloon- and stent-assisted techniques have been developed. A meta-analysis of endovascular treatments of WNBAs revealed that only 40% of patients had complete occlusion. Recently, novel devices have been developed to expand the range of treatment options. Flow-diverter stents and intra-aneurysmal flow disruption devices do not require coils; however, coil embolization remains the standard procedure used by many neurointerventionists. This review describes the recent trends in adjunctive techniques for supporting coil embolization for WNBAs. We referred to literature on balloon-assisted techniques, stent-assisted techniques, Y-stenting, PulseRider, Barrel stents, Comaneci temporary stents, pCONUS, and eCLIPs. These reports showed that adequate embolization rates were generally greater than 80%, and the complete occlusion rate was as high as 94.6%. All devices had a relatively high occlusion rate; however, it may be inaccurate to simply compare each device because of the heterogeneity of the studies. It is important to select the best treatment for each individual case by considering not only literature-based efficacy and safety but also patient background, aneurysm characteristics, and operator experience.

Some technical options for successful PulseRider procedures

Background

Unlike other conventional neck bridge stents, when using the PulseRider (PR), it is not necessary to introduce a microcatheter for stent delivery into the daughter branches from the neck, and it has less intraluminal metal. However, in some cases, securely introducing both leaflets into daughter vessels may be difficult, leading to coil herniation. This study aimed to present some technical issues in PR deployment.

Methods

Fourteen PR procedures were performed in our institution between August 2021 and June 2023, and T-type PRs were used in all procedures. Four technical points during PR procedures are presented from our experience, as "technical options (Options 1-4)". All procedures were carried out with T-type PR implants.

Results

The PR was successfully placed in all interventions; however, in seven cases (50%), some technique trials were necessary because the leaflets did not unfold in the optimal directions. In Option 1, an introduction procedure with transposition of the daughter artery using a microcatheter is presented. In Option 2, the method for correction of the unfolded leaflet angle is demonstrated. In Option 3, another method for correction of the leaflets is shown. In Option 4, an effective method for neck protection during PR procedures is shown.

Conclusion

Various options should be considered to achieve appropriate apposition of PR leaflets. These technical options may be safe and effective for successful PR deployment.

Six-month Outcomes after PulseRider- and Conventional Single Stent-assisted Embolization for Bifurcation Aneurysms: A Propensity-adjusted Comparison

Endovascular treatment of wide-necked bifurcation aneurysms (WNBAs) remains challenging despite using a stent. PulseRider is a novel device specifically designed to treat WNBAs, protecting both daughter branches, but the outcomes have not been compared with conventional single stent-assisted embolization. This study aimed to compare the six-month outcomes of PulseRider and single stent-assisted embolization for intracranial unruptured WNBAs using propensity score adjustment. Between February 2012 and October 2021, 46 unruptured WNBAs (34 basilar and 12 middle cerebral arteries) smaller than 10 mm in diameter were treated with PulseRider-assisted embolization (n = 17) or single stent-assisted embolization (n = 29). The immediate and six-month outcomes were compared using inverse probability of treatment weighting analysis. The immediate adequate occlusion rates for the PulseRider- and single stent-assisted embolization were similar (47.1% vs. 62.1%). At six months, adequate occlusion rates for the two groups were also similar (94.1% vs. 86.2%). However, the complete obliteration rate was significantly high after PulseRider-assisted embolization (88.2% vs. 41.4%, adjusted OR 10.54, 95% CI 1.93-57.63). The angiographical improvement rate was also significantly high after PulseRider-assisted embolization (70.6% vs. 37.9%, adjusted OR 6.06, 95% CI 1.54-23.76). The neurologic thromboembolic complication rate was 0% after PulseRider-assisted embolization and 3.4% after single stent-assisted embolization. PulseRider-assisted embolization of WNBAs smaller than 10 mm in diameter was associated with complete obliteration and angiographical improvement at six months. The unique shape of the PulseRider might contribute to the improved midterm aneurysm occlusion.

Usefulness of Y-shaped PulseRider-assisted coil embolization for basilar artery tip aneurysm with a misaligned axis: A case report

Background

Endovascular treatment of wide-necked bifurcation aneurysms remains challenging. Although the advent of PulseRider and Web has expanded treatment options, aneurysms with a large deviation from the parent artery axis remains difficult to treat. We present the case of a wide-necked bifurcation aneurysm that was misaligned with the angle between the long axis of the parent artery and the aneurysm and was successfully treated with Y-shaped PulseRider-assisted coil embolization.

Case Description

A 64-year-old woman presented with an unruptured basilar tip aneurysm. Cerebral angiography showed a wide-necked aneurysm measuring 8.1 mm × 6.1 mm, neck 5.7 mm. The aneurysm was strongly tilted to the right and posterior relative to the basilar artery, and the bilateral posterior cerebral artery (PCA) and superior cerebellar artery (SCA) diverged from the aneurysm body. PulseRider-assisted coil embolization was performed. A Y-shaped PulseRider was selected to be placed in a hybrid fashion with the right arch in the aneurysm and the left arch in the branch. Adequate coil embolization with preservation of the bilateral PCA and SCA was possible, and cerebral angiography immediately after the treatment showed slight dome filling. Cerebral angiography 6 months after the procedure showed that the embolic status had improved to complete occlusion.

Conclusion

For wide-neck bifurcation aneurysms with a misaligned axis, a Y-shaped PulseRider used in a hybrid fashion, in which the leaflet on the side with the tilted axis is placed in the aneurysm, allows the PulseRider to be deployed more closely to the aneurysm, thereby enabling good coil embolization.

Enterprise Treatment for Recurrent Basilar Tip Aneurysm after PulseRider-assisted Coil Embolization: A Case Report

PulseRider (Cerenovus, Irvine, CA, USA) is a relatively novel device used for the treatment of wide-neck aneurysms with a coil-assisted effect. However, treatment options for recurrent aneurysms after PulseRider-assisted coil embolization remain controversial. Here we report a case of recurrent basilar tip aneurysm (BTA) treated with Enterprise 2 after PulseRider-assisted coil embolization. A woman in her 70s underwent coil embolization for a subarachnoid hemorrhage with ruptured BTA 16 years ago. Recurrence was detected at 6-year follow-up, and an additional coil embolization was performed. Nevertheless, gradual recurrence still occurred, and PulseRider-assisted coil embolization was performed without any complications 9 years after the second treatment. However, recurrence was detected once more at 6-month follow-up. Thus, stent-assisted coil embolization using Enterprise 2 (Cerenovus) through PulseRider was selected for angular remodeling. Enterprise 2 was deployed between the right P2 segment of the posterior cerebral artery (PCA) and basilar artery (BA) after an effective coil embolization, which achieved effective angular remodeling between the right PCA and BA. The patient's postoperative course was uneventful, and no recanalization was detected after half a year. Although PulseRider is effective for wide-neck aneurysm treatment, recurrence remains a possibility. Additional treatment using Enterprise 2 is safe and effective with the expectation of angular remodeling.

Endovascular therapy versus microsurgical clipping of unruptured wide-neck aneurysms: a prospective multicenter study with propensity score analysis

OBJECTIVE

Numerous techniques have been developed to treat wide-neck aneurysms (WNAs), each with different safety and efficacy profiles. Few studies have compared endovascular therapy (EVT) with microsurgery (MS). The authors' objective was to perform a prospective multicenter study of a WNA registry using rigorous outcome assessments and to compare EVT and MS using propensity score analysis (PSA).

METHODS

Unruptured, saccular, not previously treated WNAs were included. WNA was defined as an aneurysm with a neck width ≥ 4 mm or a dome-to-neck ratio (DTNR) < 2. The primary outcome was modified Rankin Scale (mRS) score at 1 year after treatment (good outcome was defined as mRS score 0-2), as assessed by blinded research nurses and compared with PSA. Angiographic outcome was assessed using the Raymond scale with core laboratory review (adequate occlusion was defined as Raymond scale score 1-2).

RESULTS

The analysis included 224 unruptured aneurysms in the EVT cohort (n = 140) and MS cohort (n = 84). There were no differences in baseline demographic characteristics, such as proportion of patients with good baseline mRS score (94.3% of the EVT cohort vs 94.0% of the MS cohort, p = 0.941). WNA inclusion criteria were similar between cohorts, with the most common being both neck width ≥ 4 mm and DTNR < 2 (50.7% of the EVT cohort vs 50.0% of the MS cohort, p = 0.228). More paraclinoid (32.1% vs 9.5%) and basilar tip (7.1% vs 3.6%) aneurysms were treated with EVT, whereas more middle cerebral artery (13.6% vs 42.9%) and pericallosal (1.4% vs 4.8%) aneurysms were treated with MS (p < 0.001). EVT aneurysms were slightly larger (p = 0.040), and MS aneurysms had a slightly lower mean DTNR (1.4 for the EVT cohort vs 1.3 for the MS cohort, p = 0.010). Within the EVT cohort, 9.3% of patients underwent stand-alone coiling, 17.1% balloon-assisted coiling, 34.3% stent-assisted coiling, 37.1% flow diversion, and 2.1% PulseRider-assisted coiling. Neurological morbidity secondary to a procedural complication was more common in the MS cohort (10.3% vs 1.4%, p = 0.003). One-year mRS scores were assessed for 218 patients (97.3%), and no significantly increased risk of poor clinical outcome was found for the MS cohort (OR 2.17, 95% CI 0.84-5.60, p = 0.110). In an unadjusted direct comparison, more patients in the EVT cohort achieved a good clinical outcome at 1 year (93.4% vs 84.1%, p = 0.048). Final adequate angiographic outcome was superior in the MS cohort (97.6% of the MS cohort vs 86.5% of the EVT cohort, p = 0.007).

CONCLUSIONS

Although the treatments for unruptured WNA had similar clinical outcomes according to PSA, there were fewer complications and superior clinical outcome in the EVT cohort and superior angiographic outcomes in the MS cohort according to the unadjusted analysis. These results may be considered when selecting treatment modalities for patients with unruptured WNAs.

Long-term outcomes of Y-stent-assisted coil embolization using Low-profile Visualized Intraluminal Support Junior (LVIS Jr) for intracranial bifurcation aneurysms

OBJECTIVE

Y-stent-assisted coil embolization is indicated for the treatment of complex intracranial bifurcation aneurysms. However, the long-term outcomes associated with this technique remain unclear. The purpose of this study was to evaluate the long-term outcomes of Y-stent-assisted coil embolization using the Low-profile Visualized Intraluminal Support Junior (LVIS Jr) device.

METHODS

We retrospectively reviewed our databases to identify patients treated with Y-stent-assisted coiling using LVIS Jr. Digital subtraction angiography, silent magnetic resonance angiography (MRA), and time-of-flight MRA were performed at 1 year after the procedure. Patients also received an annual follow-up using MRA. Aneurysm occlusion status was classified into complete occlusion (CO), neck remnant (NR), and body filling (BF). Clinical outcomes were assessed using the modified Rankin Scale.

RESULTS

Twenty-one patients (22 aneurysms) were included in this study. All procedures were performed successfully. Immediate postprocedural angiograms showed CO in 13 aneurysms (59.1%), NR in two aneurysms (9.1%), and BF in seven aneurysms (31.8%). One-year follow-up angiograms revealed CO in 86.4% of patients. Only one patient had a major recurrence and required retreatment. The mean follow-up duration was 43.5 months. The last angiographic studies demonstrated CO in 18 aneurysms (81.8%), NR in three aneurysms (13.6%), and BF in one aneurysm (4.5%). Periprocedural and delayed complications occurred in two patients and one patient, respectively. There was no permanent morbidity or death. The modified Rankin Scale scores at last clinical follow-up were equal to those before the procedures in all patients.

CONCLUSION

Y-stent-assisted coil embolization using LVIS Jr for intracranial bifurcation aneurysms has favorable long-term angiographic and clinical outcomes.

Endovascular treatment for large (> 10 mm) basilar tip aneurysms: a retrospective case series

PURPOSE

To report the long-term clinical and angiographic outcomes of the endovascular treatment of large/giant basilar tip aneurysms (BTAs) in our institutions.

METHODS

We retrospectively reviewed cases of BTA larger than 10 mm that received endovascular treatment between January 2009 and December 2019. Data on the demographic and clinical characteristics and radiologic severity were obtained from the patients' medical records. The collected clinical follow-up data included neurological evaluation. Magnetic resonance angiography (MRA) was performed 6 to 12 months after the procedure, followed by once every 1 to 2 years as needed.

RESULTS

A total of 12 patients with BTA were included in this study. The median age was 60.08 years (27-80 years), and the mean clinical follow-up was 66.78 months (19.00-142.87 months). Almost half of the patients presented with unruptured BTAs (58.33%, n = 7). The median maximum aneurysm diameter was 13.00 mm (10.46-20.90 mm) and the mean neck size was 8.34 mm (4.82-13.04 mm). A Modified Raymond Roy Classification (MRRC1) of 1 or 2 was observed in 66.67% of the patients (n = 8) immediately after the first procedure. Procedural morbidity and mortality were 33.33% and 8.33%, respectively. Major recanalization occurred in two patients, one of whom underwent additional coiling with the other being merely observed due to older age.

CONCLUSION

It is very difficult to cure a large BTA completely at once and recanalization occurred often after endovascular treatment. Conducting long-term follow-up studies at short intervals is warranted, as well as improving existing treatment methods and developing new approaches.

Horizontal stent deployment via extracranial-intracranial bypass in coil embolization of basilar apex aneurysms: technical report

BACKGROUND

The endovascular treatment of large, wide-necked basilar apex aneurysms (BAAs) remains challenging. Although horizontal stent deployment across both P1 segments of the posterior cerebral arteries (PCAs) would be an optimal strategy in coil embolization of wide-necked BAAs, this is only feasible in cases with anatomically favorable access. In rare circumstances, large-diameter conduits of extracranial-intracranial (EC-IC) bypass can also provide a good access route for endovascular treatment of complex intracranial aneurysms.

METHODS

We describe the technique of accessing the PCA via EC-IC bypass grafts and deploying a stent horizontally across the neck of BAA and its coil embolization. We provide a detailed technical review and describe some pitfalls of the procedure.

RESULTS

Two patients underwent EC-IC bypass surgery prior to the treatment of a large, wide-necked BAA. The radial artery and saphenous vein were used as grafts, respectively. To facilitate coil embolization for a large BAA, a PCA-to-PCA horizontal stent was deployed via the bypass graft. Trans-cell and jailing techniques were used, respectively. Both aneurysms were completely occluded, and the patients were discharged without any neurological deficit.

CONCLUSION

Horizontal stent deployment via EC-IC bypass grafts can be performed safely, providing proper closure of the aneurysmal neck and apposition to both PCAs, facilitating complete coil embolization.

Brainstem Infarctions Caused by a Proximal Marker of the PulseRider Device Obstructing the Origin of a Perforator

The PulseRider (Cerenovus, Johnson & Johnson Medical Devices, New Brunswick, NJ, USA) is a neck reconstruction device that is used for the treatment of unruptured wide-necked bifurcation aneurysms. Herein, we describe the case of a 51-year-old male patient with a basilar apex aneurysm who was treated with PulseRider but had post-procedural brainstem infarctions caused by one of the proximal markers covering the origin of a perforator. In such cases, repositioning of the PulseRider should be performed to avoid infarctions.

Atypical Incomplete Detachment Following PulseRider Deployment

Objective

Owing to the limited time since the introduction of the PulseRider (PR), inconsequential or rare complications that clinicians should be aware of remain unreported yet. Here, we report a rare complication of incomplete detachment.

Case Presentation

A 50-year-old male underwent PR-assisted coil embolization for a basilar tip aneurysm. Coiling was completed, and the detachment procedure was performed using a detachment machine; the success signal was observed. The delivery microcatheter was subsequently advanced back up to the proximal markers, and no reapproximation of the proximal markers, which indicates successful detachment, was observed. However, only one of the proximal markers returned to the microcatheter, and incomplete detachment of only one leg was detected. Ultimately, electrical detachment was not possible, and physical separation by tension was achieved.

Conclusion

Our case report presents a rare case of a detachment problem in the PR. The PR could not be detached, although the signal revealed successful detachment. Therefore, careful withdrawal of the delivery wire by checking not only the proximal markers but also the behavior of the entire PR and coil complex is important.

Safety, Efficacy, and Durability of Stent Plus Balloon-Assisted Coiling for the Treatment of Wide-Necked Intracranial Bifurcation Aneurysms

BACKGROUND

Wide-necked bifurcation aneurysms remain a challenge for endovascular surgeons. Dual-stent-assisted coiling techniques have been defined to treat bifurcation aneurysms with a complex neck morphology. However, there are still concerns about the safety of dual-stenting procedures. Stent plus balloon-assisted coiling is a recently described endovascular technique that enables the coiling of wide-necked complex bifurcation aneurysms by implanting only a single stent.

OBJECTIVE

To investigate the feasibility, efficacy, safety, and durability of this technique for the treatment of wide-necked bifurcation aneurysms.

METHODS

A retrospective review was performed of patients with wide-necked intracranial bifurcation aneurysms treated with stent plus balloon-assisted coiling. The initial and follow-up clinical and angiographic outcomes were assessed. Preprocedural and follow-up clinical statuses were assessed using modified Rankin scale.

RESULTS

A total of 61 patients (mean age: 54.6 ± 10.4 yr) were included in the study. The immediate postprocedural digital subtraction angiography revealed complete aneurysm occlusion in 86.9% of the cases. A periprocedural complication developed in 11.5% of the cases. We observed a delayed ischemic complication in 4.9%. There was no mortality in this study. The permanent morbidity rate was 3.3%. The follow-up angiography was performed in 55 of 61 patients (90.1%) (the mean follow-up period was 25.5 ± 27.3 mo). The rate of complete aneurysm occlusion at the final angiographic follow-up was 89.1%. The retreatment rate was 1.8%.

CONCLUSION

The results of this study showed that stent plus balloon-assisted coiling is a feasible, effective, and relatively safe endovascular technique for the treatment of wide-necked bifurcation aneurysms located in the posterior and anterior circulation.

Y-Configuration Stenting for Coil Embolization of Complex Intracranial Aneurysms: Distinguishing Between Use of Crossing-Y and Kissing-Y

OBJECTIVE

Coil embolization with Y stenting is recognized as a suitable treatment for complex wide-necked aneurysms. Y stenting comprises crossing-Y stenting, in which a stent is passed through the interstices of another stent, and kissing-Y stenting, in which 2 stents are arranged in parallel. The purpose of this study was to elucidate how to distinguish between use of the 2 Y-stenting techniques.

METHODS

Clinical and angiographic data of patients who underwent coil embolization with Y stenting at our department from 2015 to 2019 were retrospectively analyzed. Basic characteristics, endovascular procedure, complications, and outcomes were compared between kissing-Y and crossing-Y stenting groups.

RESULTS

Thirty-eight intracranial aneurysms in 38 consecutive patients were included in this study. Nineteen patients (50%) were treated with coil embolization with kissing-Y stenting and 19 (50%) with crossing-Y. Endovascular procedures were successfully performed in all but 1 patient, in the kissing-Y group, who had stent migration. One hemorrhage (2.6%) recurred 12 months after coiling with kissing-Y stenting. Angiographic follow-up (mean, 15.8 months) was available in 35 patients. Adequate occlusion was shown in 14 patients (77.8%) and 13 patients (76.5%) in the kissing-Y and crossing-Y groups, respectively. Larger, wider-necked, and more proximal aneurysms were treated with kissing-Y stenting than with crossing-Y stenting, although there were no significant differences between the groups in complication rates or clinical outcomes.

CONCLUSIONS

Kissing-Y and crossing-Y stenting of intracranial aneurysms were both feasible and yielded reasonable angiographic and clinical results. The choice between the kissing-Y or crossing-Y-stenting technique should be decided according to the angioarchitecture of targeted aneurysms.

Efficacy and safety of PulseRider for treatment of wide-necked intracranial aneurysm-A systematic review and meta-analysis

OBJECTIVE

PulseRider is a novel self-expanding nickel-titanium (nitinol) stent for treatment of wide-necked aneurysms, which is commonly located at the arterial branches in the brain. This systematic review and meta-analysis aims to assess the efficacy and safety of PulseRider for treatment of wide-necked intracranial aneurysm.

METHOD

We performed a systematic literature search on articles that evaluate the efficacy and safety of PulseRider-assisted coiling of the wide-necked aneurysm from several electronic databases. The primary endpoint was adequate occlusion, defined as Raymond-Roy Class I + Raymond-Roy Class II upon immediate angiography and at six-month follow-up.

RESULTS

There were a total of 157 subjects from six studies. The rate of adequate occlusion on immediate angiography was 90% (95% CI, 85%-94%) and 91% (95% CI, 85%-96%) at six-month follow-up. Of these, Raymond-Roy Class I can be observed in 48% (95% CI, 41%-56%) of aneurysms immediately after coiling, and 64% (95% CI, 55%-72%) of aneurysms on six-month follow-up. Raymond-Roy Class II was found in 30% (95% CI, 23%-37%) of aneurysms immediately after coiling, and 25% (17-33) after six-month follow-up. Complications occur in 5% (95% CI, 1%-8%) of the patients. There were three intraoperative aneurysm rupture, three thrombus formation, three procedure-related posterior cerebral artery strokes, one vessel dissection, and one delayed device thrombosis. There was no procedure/device-related death.

CONCLUSIONS

PulseRider-assisted coiling for treatment of patients with wide-necked aneurysm reached 90% adequate occlusion rate that rises up to 91% at sixth month with 5% complication rate.