Treatment of a middle cerebral artery bifurcation aneurysm using a double neuroform stent "Y" configuration and coil embolization: technical case report

Y-stent-assisted coiling with Neuroform Atlas stents for wide-necked intracranial bifurcation aneurysms: A preliminary report

Objective

To report our experience on Neuroform Atlas Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms.

Methods

From March 2018 to January 2021, we treated 473 aneurysms in 436 patients with coil embolization, of which 15 cases with wide-necked bifurcation aneurysms were treated by Y-stent-assisted coiling with two Neuroform Atlas stents. We retrospectively reviewed the characteristics of patients and aneurysms, procedure-related complications, radiographic results, and clinical outcomes.

Results

All 15 cases using Neuroform Atlas Y-stenting were successful. Patients included 6 men and 9 women with a mean age ± standard deviation of 56.4±6.6 years. The mean dome and neck sizes were 6.4±3.1 mm and 4.7±1.8 mm, respectively. Immediate post-procedural angiograms showed complete occlusion in 46.7%, neck remnant in 13.3%, and incomplete occlusion in 40% of cases. No treatment-related morbidity or mortality occurred in any patients. All patients had good clinical outcomes (Glasgow Outcome Score 5) at both discharge and during a mean 12.3-month (range 1-28 months) follow-up. All aneurysms showed improved or stable occlusion on follow-up imaging. Further, the latest follow-up angiography showed complete occlusion in 73.3%, neck remnant in 6.7%, and incomplete occlusion in 20%.

Conclusions

Y-stent-assisted coiling with Neuroform Atlas stents might be a feasible and safe option for wide-necked bifurcation aneurysms.

The evolution of intracranial aneurysm treatment techniques and future directions

Treatment techniques and management guidelines for intracranial aneurysms (IAs) have been continually developing and this rapid development has altered treatment decision-making for clinicians. IAs are treated in one of two ways: surgical treatments such as microsurgical clipping with or without bypass techniques, and endovascular methods such as coiling, balloon- or stent-assisted coiling, or intravascular flow diversion and intrasaccular flow disruption. In certain cases, a single approach may be inadequate in completely resolving the IA and successful treatment requires a combination of microsurgical and endovascular techniques, such as in complex aneurysms. The treatment option should be considered based on factors such as age; past medical history; comorbidities; patient preference; aneurysm characteristics such as location, morphology, and size; and finally the operator’s experience. The purpose of this review is to provide practicing neurosurgeons with a summary of the techniques available, and to aid decision-making by highlighting ideal or less ideal cases for a given technique. Next, we illustrate the evolution of techniques to overcome the shortfalls of preceding techniques. At the outset, we emphasize that this decision-making process is dynamic and will be directed by current best scientific evidence, and future technological advances.

Endovascular coiling of proximal middle cerebral artery aneurysms: is it safe and durable?

BACKGROUND

Proximal middle cerebral artery (M1 segment) aneurysms are relatively deeply located in neighboring lenticulostriate arteries, which make them unsuitable for microsurgery. We aimed to investigate the clinical and radiological outcomes of endovascular coiling of M1 segment aneurysms.

METHODS

Between January 2003 and December 2014, we retrospectively reviewed the medical records of 52 patients (52 aneurysms) from four institutions who underwent endovascular coiling of M1 segment aneurysms. Patients who underwent clinical and radiologic follow-up for more than a year after the procedure were evaluated.

RESULTS

The aneurysms were located in the early frontal branch, early temporal branch, and lenticulostriate artery in 28, 15, and nine patients, respectively. Endovascular coiling was achieved in 51 cases and failed in one case. Of these 51 cases, 46 (90.2%) and five (9.8%) were non-ruptured and ruptured aneurysms, respectively. Initial angiographic results revealed complete occlusion in 26 (51.0%), residual neck in 16 (31.4%), and residual sac in nine (17.6%) cases. One failed case had a symptomatic procedural complication of thromboembolism. However, there was no permanent morbidity or mortality. Two major recanalization cases (3.9%) were retreated by endovascular coiling. On multivariable logistic regression analysis, aneurysmal recurrence was significantly related to aneurysm height (OR, 1.887; 95% CI, 1.107 to 3.217; p = 0.020), width (OR, 1.836; CI, 1.127 to 2.992; p = 0.015), and neck (OR, 4.017; CI, 1.220 to 13.232, p = 0.022).

CONCLUSION

Endovascular coiling of M1 segment aneurysms appeared to be a feasible treatment option with a relatively low-retreatment rate. Aneurysm size was statistically significantly associated with recurrence.

Y-configuration stenting for coiling of wide-neck bifurcation aneurysms using Low-profile Visualized Intraluminal Support Junior

Background

Little has been reported about the feasibility and durability of a Low-profile Visualized Intraluminal Support Junior (LVIS Jr) Y-stenting device for wide-neck bifurcation aneurysms.

Purpose

To evaluate the feasibility and durability of LVIS Jr Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms.

Methods

We identified patients in whom LVIS Jr Y-stenting was attempted for unruptured wide-neck bifurcation aneurysms from a prospectively maintained registry of a referral hospital. Procedural success rate, treatment-related morbidity, and clinical and angiographic outcomes were retrospectively assessed.

Results

LVIS Jr Y-stenting was attempted for a total of 21 aneurysms in 21 patients (mean age 60±8.9 years; M:F=6:15): nine basilar artery, six anterior communicating artery, four middle cerebral artery, one internal carotid artery, and one vertebrobasilar fenestration aneurysms. The mean dome and neck size were 7.9±2.7 mm and 5.7±1.8 mm, respectively. All attempts were successful. Treatment-related morbidity occurred in one individual with a modified Rankin Scale (mRS) score of 2. Immediate postprocedural angiograms showed complete occlusion in 15 (71.4%) and neck remnant in 6 (28.6%) patients. All 21 patients had good outcomes (mRS score 0–2) for a mean of 12 months' follow-up (range 6–27 months); mRS score 0 in 20 patients and mRS score 2 in one patient, respectively. Follow-up imaging over a mean of 11 months (range 6–18 months) was available in 18 patients (85.7%). All aneurysms showed complete occlusion at follow-up.

Conclusions

LVIS Jr Y-stenting and coiling for wide-neck bifurcation aneurysms seems to be feasible with acceptable safety and to provide durable aneurysm occlusion for wide-neck bifurcation aneurysms.

The LUNA aneurysm embolization system for intracranial aneurysm treatment: short-term, mid-term and long-term clinical and angiographic results

BACKGROUND AND PURPOSE

Intrasaccular aneurysm flow disruption represents an emerging endovascular approach to treat intracranial aneurysms. The purpose of this study was to determine the clinical and angiographic outcomes of using the LUNA aneurysm embolization system (AES) for treatment of intracranial aneurysms.

MATERIALS AND METHODS

The LUNA AES Post-Market Clinical Follow-Up study is a prospective, multicenter, single-arm study that was designed to evaluate device safety and efficacy. Bifurcation and sidewall aneurysms were included. Aneurysm occlusion was assessed using the Raymond-Roy classification scale. Disability was assessed using the Modified Rankin Scale (mRS). Morbidity was defined as mRS >2 if baseline mRS ≤2, increase in mRS of 1 or more if baseline mRS >2, or mRS >2 if aneurysm was ruptured at baseline. Clinical and angiographic follow-up was conducted at 6, 12 and 36 months.

RESULTS

Sixty-three subjects with 64 aneurysms were enrolled. Most aneurysms were unruptured (60/63 (95.2%)); 49 were bifurcation or terminal (49/64 (76.6%)). Mean aneurysm size was 5.6±1.8 mm (range, 3.6-14.9 mm), and mean neck size was 3.8±1.0 mm (range, 1.9-8.7 mm). Though immediate postoperative adequate occlusion was low (11/63, 18%), adequate occlusion was achieved in 78.0% (46/59) and 79.2% (42/53) of the aneurysms at 12 months and 36 months, respectively. Four patients were retreated by the 12-month follow-up (4/63 (6.3%)) and three patients were retreated by the 36-month follow-up (3/63 (4.8%)). There were two major strokes (2/63 (3.2%)), one minor stroke (1/63 (1.6%)) and three incidents of intracranial hemorrhage in two subjects (2/63 (3.2%)) prior to the 12-month follow-up. There was one instance of mortality (1/63, 1.6%). Morbidity was 0% (0/63) and 1.8% (1/63) at the 12-month and 36-month follow-ups, respectively.

CONCLUSIONS

LUNA AES is safe and effective for the treatment of bifurcation and sidewall aneurysms.

CLINICAL TRIAL REGISTRATION

ISRCTN72343080; Results.

An Update on the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction Trial: 1-Year Safety and Angiographic Results

BACKGROUND AND PURPOSE

The safety and efficacy of the PulseRider for the treatment of wide-neck, bifurcation aneurysms at the basilar and carotid terminus locations were studied in a prospective trial, the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction (ANSWER) trial, reporting on initial 6-month angiographic and clinical results. This report provides insight into the longer term durability and safety with 12-month data.

MATERIALS AND METHODS

Aneurysms treated with the PulseRider among enrolled sites were prospectively studied. Updated 12-month data on clinical and imaging end points are included.

RESULTS

Thirty-four patients were enrolled (29 women, 5 men) with a mean age of 60.9 years. The mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range, 2.3-11.6 mm). At 1 year, there were no device migrations or symptomatic in-stent stenoses. Raymond-Roy I occlusion was achieved in 53% of cases at the time of treatment and progressed to 61% and 67% at 6 and 12 months, respectively. Adequate occlusion (Raymond-Roy I/II) progressed from 88% at 6 months to 90% at 12 months. No recanalizations were observed. There was 1 delayed ischemic event. Good outcome (mRS 0-2) was achieved in 90% of patients.

CONCLUSIONS

The updated 1-year results from the ANSWER trial demonstrate aneurysm stability and an acceptable safety profile for aneurysms treated at the basilar apex and carotid terminus. Prospective data from a larger set of aneurysms treated at other locations are required to assess how treatment with PulseRider compares with alternatives for treating wide-neck bifurcation aneurysms.

Endovascular treatment of wide-neck intracranial bifurcation aneurysms with 'Y'-configuration, double Neuroform® stents-assisted coiling technique: Experience in a single center

Background Intracranial wide-neck aneurysms at the arterial bifurcations, especially in the aneurysms where the bifurcating branches emanate directly from the base of the aneurysm, have been particularly difficult on which to perform endovascular treatment. The 'Y'-configuration, double stent-assisted coil embolization is an option for the treatment of these difficult aneurysms, allowing the closure of the aneurysm, preserving the parent arteries. Material and methods In a nine-year period, 546 intracranial aneurysms in 493 patients were treated at our center by endovascular approach. We have reviewed the medical records and arteriographies from November 2007 to January 2017 of 45 patients who were treated using 'Y'-configuration double Neuroform® stent-assisted coil embolization. Results All patients were successfully treated. The location of the aneurysms were: middle cerebral artery (MCA) 20 (44.4%), anterior communicating artery (AComA) 17 (37.7%), basilar four (8.9%), internal carotid artery (ICA) bifurcation three (6.6%) and posterior communicating artery (PComA) one (2.2%). The mRS at hospital discharge was: mRS 0: 42 (93.3%), mRS 1: 1 (2.2%), mRS 2: 1 (2.2%) and mRS 5: 1 (2.2%). The Modified Raymond-Roy Occlusion Classification, in the control at six months, was: Class I: 41 (91.1%), Class II: 2 (4.4%), Class IIIa: 1 (2.2%) and Class IIIb: 1 (2.2%). Forty-four (97.8%) patients had a good outcome (mRS < 2) at six months. One (2.2%) patient had a poor outcome (mRS > 2) at six months that was due to sequelae of SAH. There was no mortality at six months. Conclusions This technique is safe and effective for the endovascular treatment of difficult wide-neck bifurcation aneurysms, allowing the stable closure of the aneurysm, preserving the parent arteries.

Middle cerebral artery aneurysm surgery after stent misplacement: A case report

Stent misplacement during endovascular treatment of middle cerebral artery (MCA) aneurysms can cause challenges and be problematic, if clipping becomes necessary. This article reports on a 56-year-old woman with an unruptured, multi-lobulated MCA aneurysm, whom primarily refused surgery; therefore, she was scheduled for stent-assisted coiling. After successful deployment of the stent, it unfortunately then became snagged by the microcatheter and was pulled backwards. The subsequent surgical procedure (i.e. clipping of the MCA aneurysm) was challenging, due to the position of the dislodged stent. Such as misplacement of the stent is rarely documented: It resulted in the difficult handling of a MCA aneurysm. Aneurysms of the MCA should primarily be considered for surgical clipping. In conclusion, an increased risk for eventual surgery should be considered, in cases where endovascular treatments with stents are performed.

Hybrid, Y-configured, dual stent-assisted coil embolization in the treatment of wide-necked bifurcation aneurysms

In Y-stenting, stabilization of the first stent may be problematic as in some cases it migrates during second stent insertion. This report evaluates the safety and effectiveness of the technique and presents the long-term results of hybrid, Y-configured, dual stent-assisted coil embolization in the treatment of wide-necked bifurcation aneurysms. We retrospectively evaluated the patients treated endovascularly due to cerebral aneurysms. Twenty patients treated with hybrid Y-stent-assisted coil embolization were enrolled in the study. In hybrid stenting, an open-cell intracranial stent (Neuroform) was used as a first stent to prevent stent migration. A closed-cell stent (Enterprise or Acclino) was used as a second stent and the aneurysm was embolized with coils between the stent struts. In all patients, hybrid Y-stenting and coil embolization were accomplished successfully. No stent migration occurred. Clinically, neither symptomatic neurologic complication nor death was seen. Of 20 wide-necked bifurcation aneurysms, nine were at the basilar tip, while seven were at the middle cerebral artery and three at the anterior communicating artery. In one patient, the aneurysm was at the A2-3 junction of the anterior cerebral artery. One of the patients had a subarachnoid hemorrhage. The mean angiographic follow-up was 25.6 months. No in-stent stenosis was seen in any of the patients and recanalization in only one. Hybrid, Y-configured, dual stent-assisted coil embolization is a safe and effective method in the treatment of wide-necked bifurcation aneurysms to prevent stent migration and aneurysm recanalization, and is a viable alternative to microsurgery.

Transfundal stent placement for treatment of complex basilar tip aneurysm: technical note

We describe a case where a complex unruptured basilar tip aneurysm was treated with a unique method of stent-assisted coil embolization. The aneurysm was considered to have a complex anatomy since both the left posterior cerebral artery and left superior cerebellar artery originated from the dome of the aneurysm. Also, the right posterior cerebral artery was incorporated in the aneurysm neck and needed to be protected prior to coil embolization. This case describes placement of a stent across the span of the aneurysm fundus in order to preserve the two branches arising from it, and the aneurysm dome was coiled without any complication. Using modifications of existing strategies for stent-assisted coil embolization, the aneurysm was treated without any complications and all of the vessels at risk were preserved.

Transfundal stent placement for treatment of complex basilar tip aneurysm: technical note

We describe a case where a complex unruptured basilar tip aneurysm was treated with a unique method of stent-assisted coil embolization. The aneurysm was considered to have a complex anatomy since both the left posterior cerebral artery and left superior cerebellar artery originated from the dome of the aneurysm. Also, the right posterior cerebral artery was incorporated in the aneurysm neck and needed to be protected prior to coil embolization. This case describes placement of a stent across the span of the aneurysm fundus in order to preserve the two branches arising from it, and the aneurysm dome was coiled without any complication. Using modifications of existing strategies for stent-assisted coil embolization, the aneurysm was treated without any complications and all of the vessels at risk were preserved.

"Y" and "X" stent-assisted coiling of complex and wide-neck intracranial bifurcation aneurysms

BACKGROUND AND PURPOSE

Stent-assisted coiling with two stents has been described in some series for the treatment of complex and wide-neck bifurcation aneurysms. Our aim was to report our experience of a stent-assisted coiling technique with double stents in "Y" and "X" configurations, with emphasis on safety, feasibility, and efficacy.

MATERIALS AND METHODS

Clinical and angiographic outcomes of patients for whom the strategic therapeutic option was the stent-assisted coiling technique in a Y or X configuration for neck scaffolding from June 2006 to June 2013 were retrospectively analyzed.

RESULTS

One hundred five aneurysms in 97 patients were treated during 100 consecutive procedures. There were 54.2% (57/105) MCA, 28.6% (30/105) anterior communicating artery, 16.2% (17/105) basilar tip, and 1.0% (1/105) ICA termination aneurysms. A Y stent placement was used to treat 87 aneurysms in 85 procedures; an X stent placement was used to treat 7 aneurysms in 6 procedures, while 9 procedures failed for 11 aneurysms. There were 10.0% (10/100) procedure-related permanent neurologic deficits and 1.0% (1/100) death. The immediate angiographic controls showed a complete occlusion in 47.6% (50/105) of the aneurysms and a partial (neck or sac remnant) occlusion in 52.4% (55/105). To date, 81.0% (85/105) of the aneurysms have been followed up (mean, 17 months) with angiography, disclosing a recanalization in 5.9% (5/85) and an improvement in 42.4% (36/85). At discharge and follow-up, the mRS score was 0 in 83.5% (81/97) of patients, 1 in 4.1% (4/97), 2 in 3.1% (3/97), 3 in 4.1% (4/97), 4 in 3.1% (3/97), and 6 in 2.1% (2/97).

CONCLUSIONS

Y and X stent-assisted coiling of complex and wide-neck intracranial bifurcation aneurysms is an effective technique.

Y-Stenting for Bifurcation Aneurysm Coil Embolization: What is the Risk?

The use of two stents in a “Y” configuration (Y-stenting) to assist with coil embolization of complex bifurcation aneurysms has been accepted as an alternative to clip reconstruction of a select subset of challenging aneurysms. We review the risks associated with Y-stenting, including its procedural complication rates, angiographic occlusion rates, rerupture, and retreatment rates.

Bacterial cellulose membranes used as artificial substitutes for dural defection in rabbits

To improve the efficacy and safety of dural repair in neurosurgical procedures, a new dural material derived from bacterial cellulose (BC) was evaluated in a rabbit model with dural defects. We prepared artificial dura mater using bacterial cellulose which was incubated and fermented from Acetobacter xylinum. The dural defects of the rabbit model were repaired with BC membranes. All surgeries were performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering. All animals were humanely euthanized by intravenous injection of phenobarbitone, at each time point, after the operation. Then, the histocompatibility and inflammatory effects of BC were examined by histological examination, real-time fluorescent quantitative polymerase chain reaction (PCR) and Western Blot. BC membranes evenly covered the surface of brain without adhesion. There were seldom inflammatory cells surrounding the membrane during the early postoperative period. The expression of inflammatory cytokines IL-1β, IL-6 and TNF-α as well as iNOS and COX-2 were lower in the BC group compared to the control group at 7, 14 and 21 days after implantation. BC can repair dural defects in rabbit and has a decreased inflammatory response compared to traditional materials. However, the long-term effects need to be validated in larger animals.

Balloons and stents in the endovascular treatment of cerebral aneurysms: vascular anatomy remodeled

Wide-neck intracranial aneurysms were originally thought to be either untreatable or very challenging to treat by endovascular means because of the risk of coil protrusion into the parent vessel. The introduction of the balloon remodeling technique (BRT) and later stents specifically designed for intracranial use has progressively allowed these lesions to be endovascularly treated. BRT and stent-assisted coiling technique (SACT) were first designed to treat sidewall aneurysms but, with gained experience and further technical refinement, bifurcation complex-shaped wide-neck aneurysms have been treated by coiling enhanced by BRT and SACT. In this article, we will review and describe the inherent benefits and drawbacks of BRT as well as SACT.

Y-crossing of braided stents with stents and flow diverters does not cause significant stenosis in bench-top studies

Y-stent placement to treat bifurcation aneurysms requires the second device to cross the confines of the first stent, with concerns regarding the formation of stenosis of the second device at the site of crossing. Various braided stents and flow diverters (FDs) were deployed to cross through a high porosity braided stent, in a Y configuration, with the ends of the devices inserted in plastic tubes of various diameters, leaving the mid-portion free to expand. The ensuing constructs were photographed, paying attention to the degree of stenosis, if any, created where the second device crosses the first stent. Experiments were repeated selecting different zones of the first stent as the site of crossing for the second device, different tube diameters, and changing the angle of the bifurcation. Crossing the first stent did not cause the second stent to become significantly stenosed in any case. Crossing through the transition or expansion zone of the first device had no influence on results. Different bifurcation angles had no influence on the occurrence of stenosis. Y-stent placement to treat arterial bifurcations using braided self-expanding stents and FDs does not lead to significant stenosis in bench-top studies.

Double stent-assisted coil embolization treatment for bifurcation aneurysms: immediate treatment results and long-term angiographic outcome

BACKGROUND AND PURPOSE

The goal of endovascular treatment of cerebral bifurcation aneurysms is to achieve safe coiling of the sac along with preserving patency of the diverging branches. Our purpose was evaluate procedural safety and efficacy as well as the long-term durability of endovascular treatment of bifurcation aneurysms with double stent-assisted coiling.

MATERIALS AND METHODS

One hundred ninety-one consecutive patients with bifurcation aneurysms were included in this series. Technical failure occurred in 3 aneurysms (1.5%); 188 patients with 193 aneurysms treated with double stent-assisted coiling were retrospectively evaluated; 113 aneurysms were located at middle cerebral artery bifurcation, 42 at the anterior communicating artery, 22 at the basilar artery bifurcation, and the remaining 16 at the internal carotid artery bifurcation; 132 were small (<10 mm), 56 were large (10-25 mm), and 5 were giant (>25 mm).

RESULTS

The technical success rate of double-stent application was 98.5% (193 aneurysms). In total, there were 5 procedural complications with an associated rate of 2.7%, one of which led to death (0.5%). Delayed ischemic stroke occurred in 2 patients (1.1%). Overall, permanent morbidity occurred in 2 patients, with associated rate of 1.1%. Follow-up was obtained in 186 aneurysms (96.4%), and recanalization occurred in 4 aneurysms (2.2%). In subgroup analysis, the recanalization rate was 3.8% for large aneurysms and 40% for giant aneurysms. No recanalization occurred in small aneurysms.

CONCLUSIONS

Dual stent-assisted coiling of cerebral aneurysms is a feasible and safe procedure. It may offer a curative solution with long-term durability for treatment of wide-neck small and large aneurysms.

Simple coiling using single or multiple catheters without balloons or stents in middle cerebral artery bifurcation aneurysms

Introduction

We evaluated the outcomes of middle cerebral artery bifurcation (MCAB) aneurysms treated with simple coiling using single or multiple catheters without stents or balloons.

Methods

This study included 100 patients with 103 MCAB aneurysms who underwent a simple coiling procedure without the adjuvant use of stents or balloons. The angiographic clinical outcomes and recurrence of these aneurysms were evaluated.

Results

Of the 103 aneurysms, 102 (99.0 %) aneurysms were successfully treated with simple coiling. One patient died from the consequences of a procedural aneurysm rupture. The treatment-associated permanent morbidity and mortality rates were 0 and 1.0 %, respectively. Post-coiling angiograms showed 28 complete occlusions (27.2 %), 60 neck remnants (58.3 %), and 14 partial occlusions (13.6 %). A follow-up angiography (median duration, 30 months; range, 3–73 months) was performed in 80 lesions. Recanalisation was found in 28 lesions (35.0 %), of which 6 were complete occlusions, 18 were neck remnants, and 4 were partial occlusions, as determined by post-coiling angiograms. Among these lesions, 14 major recurrences were retreated with coiling (n = 12) and clipping (n = 2) without complications. Age (odds ratio [OR], 0.93; 95 % confidence interval [CI], −0.11 to −0.01; p = 0.03), the presence of a rupture (OR, 3.89; 95 % CI, 0.12 to 2.60; p = 0.03), and a wide aneurysm neck (OR, 6.40; 95 % CI, 0.57 to 3.14; p = 0.005) were significantly associated with the aneurysm recurrence, as determined by multivariable analyses.

Conclusion

Our study suggests that simple coiling of MCAB aneurysms is feasible and safe; however, it has limitations in durability, particularly in ruptured or wide-necked aneurysms and in young patients.

Y-stenting endovascular treatment for ruptured intracranial aneurysms : a single-institution experience in Korea

Objective

Stent-assisted coiling on intracranial aneurysm has been considered as an effective technique and has made the complex aneurysms amenable to coiling. To achieve reconstruction of intracranial vessels with preservation of parent artery the use of stents has the greatest potential for assisted coiling. We report the results of our experiences in ruptured wide-necked intracranial aneurysms using Y-stent coiling.

Methods

From October 2003 to October 2011, 12 patients (3 men, 9 women; mean age, 62.6) harboring 12 complex ruptured aneurysms (3 middle cerebral artery, 9 basilar tip) were treated by Y-stent coiling by using self-expandable intracranial stents. Procedural complications, clinical outcome, and initial and midterm angiographic results were evaluated. The definition of broad-necked aneurysm is neck diameter over than 4 mm or an aneurysm with a neck diameter smaller than 4 mm in which the dome/neck ratio was less than 2.

Results

In all patients, the aneurysm was successfully occluded with no apparent procedure-related complication. There was no evidence of thromboembolic complication, arterial dissection and spasm during procedure. Follow-up studies showed stable and complete occlusion of the aneurysm in all patients with no neurologic deficits.

Conclusion

The present study did show that the Y-stent coiling seemed to facilitate endovascular treatment of ruptured wide-necked intracranial aneurysms. More clinical data with longer follow-up are needed to establish the role of Y-stent coiling in ruptured aneurysms.

[Assisted techniques for the endovascular treatment of complex or atypical cerebral aneurysms]

In the last ten years, the endovascular approach to the management of cerebral aneurysms has gone from being an alternative to surgery to being the first-choice technique in the vast majority of cases. The continuous development of new assisted techniques and of new materials for embolization have multiplied its therapeutic possibilities, so that safe and efficacious endovascular treatment is now possible for aneurysms that would have required surgery only a few years ago. These continuous technological advances require the professionals that treat patients with cerebral aneurysms to achieve a high degree of specialization and to keep up to date through continuous training. In this article, we review some of the most widely used assisted techniques in the endovascular treatment of cerebral aneurysms, discussing their main indications, their advantages over conventional embolization techniques, and their possible limitations.

Stent-assisted coiling of intracranial bifurcation aneurysms leads to immediate and delayed intracranial vascular angle remodeling

BACKGROUND AND PURPOSE

Wide-neck bifurcating aneurysms are increasingly treated with intracranial stent-assisted coiling by using shape-memory alloy microstents. We sought to investigate the short- and long-term effects of intracranial stent implantation on the geometry and angular conformation of the stent-coiled vascular bifurcation.

MATERIALS AND METHODS

Thirty patients underwent stent-mediated coiling for 31 bifurcation aneurysms by using 31 self-expanding Neuroform (n = 14) and Enterprise (n = 17) stents (17 women; mean age, 56 years). The angle (δ) between the stented mother and daughter vessels at the bifurcation was measured by using multiplanar imaging of reconstructed rotational conventional angiography volumes and was compared by using matched-pair statistics. Neuroform and Enterprise longitudinal stent stiffness was measured in vitro at an increasing bending angle θ (θ = 180°-δ).

RESULTS

Stent deployment increased the bifurcation angle δ from 101.5° to 119.8° postprocedurally and to 137.3° (P < .0001) at latest follow-up, resulting in effective straightening; the angular remodeling was greater in distal-versus-proximal arteries (anterior cerebral > MCA > BA > ICA), inversely proportional to mother-vessel diameter and proportional to pretreatment bending angle θ. At follow-up, angle δ continued to significantly expand, with remodeling being greater in the early period (1-6 versus >7 months) and more pronounced with the longitudinally stiffer closed-cell Enterprise compared with the open-cell Neuroform stent.

CONCLUSIONS

Stent placement across bifurcation aneurysms leads to a significant biphasic angular remodeling related to stent type and vessel caliber, altering morphology to mimic sidewall lesions, a phenomenon needing consideration during procedural planning. Future work is needed to uncover the hemodynamic implications of this structural change and any possible effect on aneurysm-recurrence rates.

Stent-assisted coil embolization of complex wide-necked bifurcation cerebral aneurysms using the "waffle cone" technique. A review of ten consecutive cases

Endovascular treatment of complex, wide-necked bifurcation cerebral aneurysms is challenging.  Intra/extra-aneurysmal stent placement, the "waffle cone" technique, has the advantage of using a single stent to prevent coil herniation without the need to deliver the stent to the efferent vessel. The published data on the use of this technique is limited. We present our initial and follow-up experience with the waffle cone stent-assisted coiling (SAC) of aneurysms to evaluate the durability of the technique. We retrospectively identified ten consecutive patients who underwent SAC of an aneurysm using the waffle cone technique from July 2009 to March 2011. Clinical and angiographic outcomes after initial treatment and follow-up were evaluated. Raymond Class I or II occlusion of the aneurysm was achieved in all cases with the waffle cone technique. No intraoperative aneurysm rupture was noted. The parent arteries were patent at procedure completion. Clinical follow-up in nine patients (median 12.9 months) revealed no aneurysm rupture. Two patients had a transient embolic ischemic attack at 18 hours and three months after treatment, respectively. Catheter angiography or MRA at six-month follow-up demonstrated persistent occlusions of aneurysms in seven out of eight patients. Another patient had stable aneurysm occlusion at three-month follow-up study. Our experience in the small series suggests the waffle cone technique could be performed on complex, wide-necked aneurysms with relative safety, and it allowed satisfactory occlusions of the aneurysms at six months in most cases.

Initial Experience with Neuroform EZ in the Treatment of Wide-neck Cerebral Aneurysms

Purpose

Stent-assisted coiling allows embolization and parent vessel reconstruction of wide-necked intracranial aneurysms. The Neuroform EZ (Boston Scientific, Fremont, CA, U.S.A.) stent delivery system offers deployment of a Neuroform stent with fewer steps and improved operator control. Initial experience, technical considerations, and treatment outcomes using the Neuroform EZ stent delivery system in combination with coil embolization are reported.

Materials and Methods

Seventeen consecutive patients harboring 21 wide-necked saccular cerebral aneurysms were treated with stent reconstruction. Twenty aneurysms were unruptured; one was treated within 24 hours of diagnosis of rupture. Twenty aneurysms were located in the anterior circulation; one was in the posterior circulation. Immediate and six-month post-treatment angiography and clinical assessment were performed.

Results

In all cases, the stents were delivered and positioned without difficulty in deployment. Technical complications occurred in 4 patients, but none were directly related to the stent delivery system. On immediate post-treatment angiography, 5 of 21 aneurysms showed complete occlusion, 5 of 21 showed residual neck, and 11 of 21 showed residual contrast filling of the aneurysm sac. At six month follow-up, all 17 patients were clinically stable. Angiography of 18 of the aneurysms showed total occlusion in 12, residual neck in 3, and residual aneurysm filling in 3. Retreatment was performed in the three with residual aneurysm.

Conclusion

The Neuroform EZ stent system offers improved anchoring and support in stent delivery, which is particularly useful when multiple stents are overlapped to further protect the parent vessel and increase flow diversion away from the aneurysm sac. The only significant problem encountered was coil prolapse, which could be treated with a second stent when necessary. The ease of deployment improves upon the already clinically successful Neuroform design.

A novel "Y" stent flow diversion technique for the endovascular treatment of bifurcation aneurysms without endosaccular coiling

BACKGROUND AND PURPOSE

Stent-assisted endovascular treatment and flow diversion techniques are increasingly used for the management of wide-neck intracranial aneurysms. We report our initial clinical experience using a new flow diversion technique for the endovascular management of bifurcation aneurysms.

MATERIALS AND METHODS

Eight bifurcation aneurysms were treated by placing 2 stents in Y-configuration with no accompanying endosaccular packing. This treatment technique aimed at flow diversion was selected in these cases because 1) the aneurysm was giant and causing mass effect, 2) the emanating branches were incorporated within the sac, or 3) the aneurysm was too small. Aneurysms were located at middle cerebral (5 aneurysms) and basilar artery bifurcations (3 aneurysms). Five aneurysms were small, 1 was large, and 2 were partially thrombosed giant. Closed-cell stents were used in all Y-stent placement procedures.

RESULTS

In all aneurysms, both stents could be placed at the intended locations without any procedural complication. Follow-up angiograms obtained at 3 months to 2 years demonstrated that all stents were patent except for one with asymptomatic P1 occlusion. Complete occlusion with remodelled bifurcation was observed in all middle cerebral artery bifurcation aneurysms and the large basilar tip aneurysm. Residual filling despite reduction in size was observed in both of the partially thrombosed giant aneurysms at 2-year and 3-month follow-up angiograms, respectively.

CONCLUSIONS

Flow diversion with double stent placement in Y-configuration provided successful and stable aneurysm occlusion. The technical and clinical results achieved are highly encouraging that this technique may contribute to the endovascular treatment of these complex bifurcation aneurysms.

Y-stent-assisted coil embolization of wide-neck intracranial aneurysms. A single center experience

This report evaluated the short and midterm results of the safety and effectiveness of the treatment technique with hybrid and non-hybrid Y-configured, dual stent-assisted coil embolization of wide-neck intracranial aneurysms, and reviewed the literature concerning this technique. Nine patients, eight with unruptured and one with ruptured aneurysms were included in the study. Of aneurysms embolized with a hybrid (with two different stents) and non-hybrid (with two identical stents) technique, three were located in the anterior communicating artery, three at the tip and one at the distal site of basilar artery, and two in the middle cerebral artery. All aneurysms included the orifices of bifurcation vessels. All aneurysms were stented and embolized during the same session. While Neuroform and Enterprise stents were used in the hybrid technique, two Enterprise stents were used in the non-hybrid technique. Dual Y-stent assisted coil embolization was performed successfully in eight of nine patients (88.9%), including five patients (55.6%) with hybrid and three patients (33.3%) with non-hybrid technique. No procedural complication, no mortality and no minor or major neurological complications were seen during the angiographic or clinical follow-up. When an attempt was made at passing the second stent through the first Enterprise stent, the stent protruded inside the aneurysm in one patient (11.1%). Hybrid or non-hybrid dual Y-stent-assisted coil embolization in the treatment of ruptured or unruptured wide-neck and complex intracranial aneurysms is a safe and effective method from the viewpoint of short and midterm results.

Endovascular treatment of complex intracranial aneurysms using intra/extra-aneurysmal stent

BACKGROUND

Intra/extra-aneurysmal stent placement for treatment of complex and wide-necked bifurcation aneurysms has been previously described. However, this technique has been rarely reported in the treatment of dissecting aneurysms with incorporated vessels. We assess the feasibility and effectiveness of intra/extra-aneurysmal stent-assisted coil embolization in the treatment of those complex intracranial aneurysms.

METHODS

Between January 2009 and April 2010, nine consecutive patients with wide-necked or dissecting aneurysms with incorporated vessels underwent endovascular treatment using intra/extra-aneurysmal stent-assisted coiling at our institution. We assessed the clinical history, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

All Neuroform stents were successfully deployed in this series. Of the nine aneurysms treated with stent-assisted embolization, complete occlusion was achieved in seven aneurysms, nearly complete in one, and incomplete was present in one. There was no procedure-related complication in this series. Angiographic follow-up results of eight patients (mean, 8.6 months) showed continued obliteration of the aneurysms in six patients, incomplete occlusion in two patients, and the two patients received second treatment. On the modified Rankin Scale applied in follow-up, all patients were assessed as functionally improved or of stable clinical status.

CONCLUSIONS

Intra/extra-aneurysmal stent placement and subsequent coil embolization may be effective for the treatment of selected patients with complex intracranial aneurysms. Short-term follow-up data indicate good durability of stent-assisted aneurysm occlusion. However, further study with longer follow-up and larger case series is necessary for validation of the efficacy of this treatment modality.

Flow changes after endovascular treatment of a wide-neck anterior communicating artery aneurysm by using X-configured kissing stents (cross-kissing stents) technique

Endovascular treatment for a wide-neck anterior communicating artery (AcomA) aneurysm remains technically challenging. Stent-assisted embolization has been proposed as an alternative of treatment of complex aneurysms. The X-configuration double-stent-assisted technique was used to achieve successful coiling of wide-neck AcomA aneurysm. Implanted stent can alter intra-arterial flow. Follow-up angiograms 4 months later showed flow changes due to used X-technique of stents implantation and filling of the anterior cerebral artery from the opposite internal carotid artery.

Management of giant middle cerebral artery aneurysms with incorporated branches: partial endovascular coiling or combined extracranial-intracranial bypass--a team approach

OBJECTIVE

Our goal was to assess the long-term anatomic and clinical outcomes in patients with giant middle cerebral artery (MCA) aneurysms treated by endovascular coil embolization alone or in combination with cerebral revascularization.

METHODS

One hundred twenty-six patients with giant intracranial aneurysms were endovascularly treated at the University of California, Los Angeles, between 1990 and 2007. Of these, 9 patients had partially thrombosed MCA aneurysms with incorporated branches. Five patients presented with symptoms of mass effect, 3 had seizures, 2 had episodes of brain ischemia, and 1 presented with acute subarachnoid hemorrhage.

RESULTS

Three wide-neck saccular aneurysms were almost completely coil occluded, leaving only small neck remnants that were intended to preserve the patency of incorporated MCA branches. The other 6 fusiform aneurysms were effectively treated by superficial temporal artery-MCA or occipital artery-MCA bypass, followed by complete coil occlusion of these aneurysms. Immediate angiograms and mid- or long-term neuroradiological imaging follow-up examinations revealed complete obliteration or near-complete occlusion (90%-99%) of the aneurysms in all 9 patients. Seven patients had a favorable long-term clinical outcome, and 1 patient died as a result of unrelated congestive heart failure. One patient required emergent surgical aneurysm thrombectomy because of inadvertent coil occlusion of the frontal opercular artery, which was not protected by the bypass, and the patient subsequently sustained a moderate neurological disability.

CONCLUSION

Giant MCA aneurysms with branch incorporations and other unfavorable features such as intraluminal thrombus, mural calcification, and fusiform configuration can be effectively treated with a team approach, using coil embolization after protective surgical bypass. When aneurysms with MCA branches incorporated into the neck rather than the dome are treated by endovascular techniques alone, long-term angiographic follow-up is necessary to assess and further treat any significant remnant.

Treatment of intracranial aneurysms by functional reconstruction of the parent artery: the Budapest experience with the pipeline embolization device

BACKGROUND AND PURPOSE

Aneurysm treatment by intrasaccular packing has been associated with a relatively high rate of recurrence. The use of mesh tubes has recently gained traction as an alternative therapy. This article summarizes the midterm results of using an endoluminal sleeve, the PED, in the treatment of aneurysms.

MATERIALS AND METHODS

A total of 19 wide-neck aneurysms were treated in 18 patients: 10 by implantation of PEDs alone and 9 by a combination of PED and coils. Angiographic and clinical results were recorded immediately and at 6 months following treatment.

RESULTS

Immediate angiographic occlusion was achieved in 4 and flow reduction, in another 15 aneurysms. Angiography at 6 months demonstrated complete occlusion in 17 and partial filling in 1 of 18 patients. There was no difference between coil-packed and unpacked aneurysms. Of 28 side branches covered by > or =1 device, the ophthalmic artery was absent immediately in 1 and at 6 months in another 2 cases. One patient experienced abrupt in-stent thrombosis resulting in a transient neurologic deficit, and 1 patient died due to rupture of a coexisting aneurysm. All giant aneurysms treated with PED alone were demonstrated by follow-up cross-sectional imaging to have involuted by 6 months.

CONCLUSIONS

Treatment of large, wide-neck, or otherwise untreatable aneurysms with functional reconstruction of the parent artery may be achieved with relative safety using dedicated flow-modifying devices with or without adjunctive use of intrasaccular coil packing.

Endovascular treatment of wide-neck middle cerebral artery aneurysms with stents: a review of 16 cases

BACKGROUND AND PURPOSE

MCA aneurysms are common and often pose technical challenges to interventionalists. Intracranial stents are widely used in treating wide-neck aneurysms in other locations. To evaluate the feasibility, effectiveness, and safety of stent placement in MCA aneurysms, we performed this retrospective study.

MATERIALS AND METHODS

Between October 2003 and May 2009, 16 patients with 16 wide-neck MCA aneurysms were treated with stents at our institution. We retrospectively collected and analyzed the data for these patients, including demographics, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

Seventeen stents, including 12 Neuroform, 4 LEO, and 1 Enterprise, were successfully deployed in this series. Of the 13 aneurysms treated with stent-assisted embolization, complete occlusion was achieved in 9 aneurysms; residual neck remained in 1, and residual aneurysm was present in 3. Contrast stasis in the aneurysm sac was observed in the other 3 aneurysms treated with stent alone. Procedure-related complication occurred in 1 patient, leading to no permanent effect. The mRS score at discharge was 0-2 in 14 patients and 3-6 in 2. The angiographic follow-up results of 9 patients (mean, 5.6 months) showed that all aneurysms remained stable or improved; there was no in-stent stenosis, recurrence, or retreatment. The clinical follow-up (mean, 20.1 months) demonstrated no neurologic deterioration or rebleeding.

CONCLUSIONS

Our preliminary experience demonstrates that stent placement for the treatment of selected wide-neck MCA aneurysms is feasible. However, its safety and efficacy should be further evaluated by larger case series and more adequate follow-up.