WingSpan Stent System in the endovascular treatment of intracranial aneurysms: clinical experience with midterm follow-up results

OBJECT: The WingSpan stent is a new self-expandable neurovascular stent designed for endovascular treatment of intracranial atheromatous lesions. The authors report their experience with the use of this stent for the endovascular treatment of intracranial aneurysms. METHODS: Thirty-seven patients with 40 wide-necked intracranial aneurysms were treated using the WingSpan stent. Twenty-two aneurysms (55%) were small and 18 (45%) were large or giant. In all but 4 aneurysms, embolization was completed by packing the aneurysm sac with platinum coils. In 4 dissecting aneurysms that were fusiform or too small and wide necked to be catheterized, the stent was used alone. In these cases, the stent bridged the aneurysm neck to allow for flow redirection and the potential stent-induced endothelization effect. RESULTS: Follow-up angiograms obtained in 3 of 4 aneurysms, treated with only stent placement, demonstrated aneurysmal thrombosis and parent artery remodeling in 2 patients and moderate decrease in size in 1. Follow-up angiography obtained at 6 months to 1 year in 31 aneurysms after stent-supported coil embolization demonstrated complete occlusion in 23 aneurysms (74.2%) with a progressive thrombosis rate of 66.7% (10 of 15 aneurysms), and a recanalization rate of 16.1%. CONCLUSIONS: In treating wide-necked intracranial aneurysms, the WingSpan Stent System is very flexible, secure, and effective. Its delivery system is very easy and exact in that it exerts higher outward radial force, thus providing an excellent conformability and a strong scaffold to hold the coils in place. It may offer an effective treatment when used alone in some fusiform or very wide-necked, small dissecting aneurysms in which other surgical or endovascular treatment strategies are not deemed feasible.     

Transluminal stent-assisted coil embolization of a vertebral confluence aneurysm: technique report

BACKGROUND: Recent advances in stent technology have allowed for negotiation of often tortuous posterior circulation intracranial vasculature. Stent-assisted coil embolization is a novel treatment for complex wide-necked aneurysms, as stents provide a buttress that allows for coil deposition while preventing coil herniation into the parent vessel lumen. We describe a case of stent-assisted coil embolization of a complex wide-necked vertebral confluence aneurysm. CASE DESCRIPTION: A 61-year-old woman presented with a Hunt-Hess III, Fisher Grade III subarachnoid hemorrhage secondary to a ruptured vertebral confluence aneurysm demonstrated on angiography. The patient underwent emergent angiography and attempted coiling of a vertebral confluence aneurysm. Because of the aneurysm's complex wide neck and the presence of subclavian steal syndrome, the coils repeatedly herniated into the left vertebral and basilar artery lumina. A flexible coronary stent was deployed across the aneurysm neck, preventing coil herniation and allowing for greater coil deposition. The patient tolerated the procedure and underwent repeat coiling 2 months postoperatively because of mild coil compaction. This resulted in 100% occlusion and the patient is neurologically normal except for a sixth nerve palsy which had been present after the hemorrhage. CONCLUSION: Recent advances in stent technology allow negotiation of the tortuous posterior circulation vasculature. Stent-assisted coil embolization of complex, wide-necked vertebral confluence aneurysms may be an alternative intervention for these surgically challenging lesions.     

Efficacy and current limitations of intravascular stents for intracranial internal carotid, vertebral, and basilar artery aneurysms.

OBJECT: Results of previous in vitro and in vivo experimental studies have suggested that placement of a porous stent within the parent artery across the aneurysm neck may hemodynamically uncouple the aneurysm from the parent vessel, leading to thrombosis of the aneurysm. For complex wide-necked aneurysms, a stent may also aid packing of the aneurysm with Guglielmi detachable coils (GDCs) by acting as a rigid scaffold that prevents coil herniation into the parent vessel. Recently, improved stent system delivery technology has allowed access to the tortuous vascular segments of the intracranial system. The authors report here on the use of intracranial stents to treat aneurysms involving different segments of the internal carotid artery (ICA), the vertebral artery (VA), and the basilar artery (BA). METHODS: Ten patients with intracranial aneurysms located at ICA segments (one petrous, two cavernous, and three paraclinoid aneurysms), the VA proximal to the posterior inferior cerebellar artery origin (one aneurysm), or the BA trunk (three aneurysms) were treated since January 1998. In eight patients, stent placement across the aneurysm neck was followed (immediately in four patients and at a separate procedure in the remaining four) by coil placement in the aneurysm, accomplished via a microcatheter through the stent mesh. In two patients, wide-necked aneurysms (one partially thrombosed BA trunk aneurysm and one paraclinoid segment aneurysm) were treated solely by stent placement; coil placement may follow later if necessary. No permanent periprocedural complications occurred and, at follow-up examination, no patient was found to have suffered symptoms referable to aneurysm growth or thromboembolic complications. Greater than 90% aneurysm occlusion was achieved in the eight patients treated by stent and coil placement as demonstrated on immediate postprocedural angiograms. Follow-up angiographic studies performed in six patients at least 3 months later (range 3-14 months) revealed only one incident of in-stent stenosis. In the four patients originally treated solely by stent placement, no evidence of aneurysm thrombosis was observed either immediately postprocedure or on follow-up angiographic studies performed 24 hours (two patients), 48 hours, and 3 months later, respectively. CONCLUSIONS: A new generation of flexible stents can be used to treat complex aneurysms in difficult-to-access areas such as the proximal intracranial segments of the ICA, the VA, or the BA trunk. The stent allows tight coil packing even in the presence of a wide-necked, irregularly shaped aneurysm and may provide an endoluminal matrix for endothelial growth. Although convincing experimental evidence suggests that stent placement across the aneurysm neck may by itself promote intraluminal thrombosis, the role of this phenomenon in clinical practice may be limited at present by the high porosity of currently available stents.     

Percutaneous intracranial stent placement for aneurysms

OBJECT: Intracranial stent placement combined with coil embolization is an emerging procedure for the treatment of intracranial aneurysms. The authors report their results using intracranial stents for the treatment of intracranial aneurysms. METHODS: A prospectively maintained database was reviewed to identify all patients with intracranial aneurysms that were treated with intracranial stents. Ten lesions, including eight broad-based aneurysms and two dissecting aneurysms, were treated in 10 patients. Four lesions were located in the cavernous segment of the internal carotid artery, two at the vertebrobasilar junction, two at the basilar trunk, one at the basilar apex, and one in the intracranial vertebral artery. Attempts were made to place stents in 13 patients, but in three the stents could not be delivered. Altogether, intracranial stents were placed in 10 patients for 10 lesions. Results that were determined to be satisfactory angiographically were achieved in all 10 lesions. Two patients suffered permanent neurological deterioration related to stent placement. In two patients, the aneurysm recurred after stent-assisted coil embolization. In one case of recurrence a second attempt at coil embolization was successful, whereas in the second case of recurrence parent vessel occlusion was required and well tolerated. CONCLUSIONS: Intracranial stents can be a useful addition to coil embolization by providing mechanical, hemodynamic, and visual benefits in the treatment of complex, broad-based aneurysms.     

Double-stent method: therapeutic alternative for small wide-necked aneurysms. Technical note

The authors present two cases of patients with small, acutely ruptured, wide-necked aneurysms of the distal vertebral artery that were not amenable to conventional coil embolization and were instead treated by means of a double-stent method in which one stent was placed inside another. Angiography performed immediately after the procedure revealed a significant reduction in aneurysm filling; total occlusion of the lesion was observed after 7 days and confirmed 6 months later in both aneurysms. By placing one stent inside the other, stent permeability can be reduced, which may result in significant hemodynamic changes with accelerated aneurysm thrombosis. This double-stent method may represent a therapeutic alternative, especially in cases of small, wide-necked aneurysms in which conventional endovascular techniques or stent-supported coil embolization is not considered feasible or is believed to be too dangerous, and surgical treatment is contra-indicated.     

Parent vessel Guglielmi detachable coil herniation during wide-necked aneurysm embolization: treatment with intracranial stent placement: two technical case reports

OBJECTIVE AND IMPORTANCE: Despite recent advances in technology, parent vessel coil herniation occasionally complicates successful Guglielmi detachable coil embolization, particularly in wide-necked aneurysms. We report endovascular stent deployment performed in two patients specifically to treat this complication. CLINICAL PRESENTATION: Two patients underwent Guglielmi detachable coil embolization of cavernous segment aneurysms. Both developed coil herniation into the internal carotid artery. In one patient, the herniation occurred during the initial procedure; in the other, it was discovered in a delayed fashion during a follow-up examination for ocular symptoms. INTERVENTION: In both patients, endovascular stent deployment was performed to isolate the herniated portion of the coil from the internal carotid lumen. Follow-up angiography at 6 months demonstrated no aneurysm recanalization and no stenosis of the parent internal carotid artery in the stented region in either patient. CONCLUSION: The use of intraluminal stents has been reported to be a helpful technical adjunct to the conventional endovascular treatment of aneurysms and balloon angioplasty. One additional indication for the use of this technology is sequestering herniated coils from the lumen of the parent artery to reduce potential embolic or occlusive sequelae.     

Balloon-assisted coil placement in wide-necked cerebral aneurysms: preliminary clinical experience

Endovascular treatment of wide-necked cerebral aneurysms with Guglielmi detachable coils (GDCs) has been limited due to coil protrusion into the artery. Seven patients with wide-necked cerebral aneurysms were treated with GDCs with temporary balloon inflation for mechanical protection during coil placement. Transarterial embolization of the aneurysm with GDCs had failed due to coil protrusion into the parent artery. The use of simultaneous temporary balloon protection achieved more dense intra-aneurysmal coil packing, especially in the neck, without compromising the parent artery.     

Single-center experience with the Neuroform stent for endovascular treatment of wide-necked intracranial aneurysms

Background

Stent-assisted coiling is an accepted endovascular treatment (EVT) for wide-necked intracranial aneurysms. The Neuroform stent (Target Therapeutics, Fremont, Calif) is a flexible nitinol self-expandable stent that was designed to potentially overcome the limitations of balloon expandable coronary stents in the intracranial circulation. The aim of this study was to reenforce the use of this stent for EVT of wide-necked cerebral aneurysms.

Methods

Between March 2005 and March 2008, 24 patients harboring wide-necked cerebral aneurysms were treated with stent reconstruction of the aneurysm neck. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate postprocedure angiography studies were performed to determine successful coil occlusion of the aneurysm as well as patency of the parent vessel. We assessed the clinical history, aneurysm dimensions, and technical detail of the procedures, including any difficulties with stent placement and deployment, degree of aneurysm occlusion, and complications. Clinical outcome was assessed with the Glasgow Outcome Scale (GOS).

Results

The stent was easily navigated and precisely positioned in 24 of 26 cases. However, technical difficulties occurred in 9 patients, including difficulties in crossing the stents interstice in 6 cases, inadvertent stent delivery (n = 1), and incapacity of stent delivery (n = 1) and incapacity of crossing the neck (n = 1). These latter 2 cases were classified as failures of the stent-assisted technique. A single procedural complication occurred, involving transient nonocclusive intrastent thrombus formation, which was treated uneventfully with abciximab. Seventeen patients experienced excellent clinical outcomes (GOS 5), with good outcomes (GOS 4) in 5 patients and a poor outcome (GOS 3) in 2 patients. There were no treatment-related deaths or neurologic complications (mean clinical follow-up, 12 months). Angiographic results consisted of 17 complete occlusions, 4 neck remnants, and 3 incomplete occlusions.

Conclusions

The Neuroform stent is very useful for EVT of wide-necked intracranial aneurysms because it is easy to navigate and to deploy accurately. In most cases, the stent can be deployed precisely, even in very tortuous carotid siphons. Although in some cases delivery and deployment was challenging, clinically significant complications were not observed.     

Stent-assisted Gugliemi detachable coil repair of wide-necked renal artery aneurysm using 3-D angiography

PURPOSE: To report a wide-necked renal artery aneurysm treated successfully with stent-assisted Gugliemi detachable coil occlusion, assisted by three-dimensional (3-D) angiography. CASE REPORT: A 56-year-old woman with history of hypertension presented with a 2.5-cm wide-necked saccular aneurysm involving her distal right renal artery. A balloon-expandable stent was positioned across the neck of the aneurysm and multiple Gugliemi detachable coils were deployed through a microcatheter inserted through the interstices of the stent into the aneurysm sac, guided by 3-D angiography. Follow-up 3-D angiography at 6 months revealed a patent renal artery with continued exclusion of the aneurysm and preservation of renal blood flow. CONCLUSION: Stent-assisted coil occlusion assisted by 3-D angiography is a potential renal-sparing endovascular approach to treating wide-necked renal artery aneurysms with complex vascular anatomy.     

Computational fluid dynamics analysis of intracranial aneurysms treated with flow diverters: A case report

IntroductionIntracranial aneurysms (IAs) are localized dilatations of intracranial arteries due to weaknesses of the endothelial layer. IAs may be treated by flow diverters (FDs), alternatively to stents and coils combination. FD is a method for the treatment of IAs especially for large, wide-necked or fusiform aneurysms. In this case report, we described a 65-year-old woman with IA who were treated by FD.Case presentationA 65-year-old woman was diagnosed with a giant aneurysm at the posterior inferior cerebellar artery segment of the left internal carotid artery. Then based on the computed tomography data of this woman, aneurysm vascular stent model was constructed before and after FD, and internal pressure, velocity, wall shear stress (WSS) of aneurysms were determined by CFD analysis. Standard boundary conditions were applied. It was found that a single FD stent and double FD stents decreased the blood flow and WSS of aneurysm. The effect of single FD stent + 30% filling on blood flow was more obvious, but the aneurysm rupture was caused by excessive coil packing. So, a single stent + 10% coil packing rate was the best option for treating aneurysms.ConclusionsCFD analysis for flow velocity and WSS have protection on aneurysms.     

Endovascular management of a ruptured cavernous carotid artery aneurysm associated with a carotid cavernous fistula with an intracranial self-expanding microstent and hydrogel-coated coil embolization: case report and review of the literature

BACKGROUND: Ruptured CCAs are traditionally treated with endovascular management. Advances in microstent and coil technology have allowed improved intracranial navigation, increased coil packing density, and coil volume expansion to facilitate complete coil embolization of aneurysms/fistulae. We report a case of a ruptured CCA with an associated CCF treated with an intracranial, self-expanding microstent in combination with coil embolization using hydrogel-coated platinum coils. CASE DESCRIPTION: A 50-year-old woman presented with a 7-day history of severe headache and 2 days of progressive left-sided ptosis, ophthalmoplegia, and facial dysesthesias. A cerebral angiogram demonstrated a left ruptured wide-necked CCA with an associated CCF. An intracranial, self-expanding microstent (Neuroform(3), Boston Scientific, Natick, MA) was placed across the aneurysmal neck. The aneurysm was subsequently embolized with hydrogel-coated platinum coils (HydroCoil). A 3-month follow-up angiogram showed complete resolution of arteriovenous shunting with near-complete occlusion of the CCA. The patient's ocular pain and facial dysesthesias resolved completely, with near-complete resolution of ophthalmoplegia. CONCLUSIONS: This case demonstrates near-complete occlusion of a ruptured CCA and obliteration of an associated CCF using endovascular combinational therapy of an intracranial, self-expanding microstent with hydrogel-coated platinum coils. Use of this newer-generation stent-coil combination may allow more complete and durable lesion occlusion because of increased coil packing density and coil volume expansion without the need for parent artery sacrifice or balloon-remodeling techniques, thus avoiding the potential complications of such therapies.     

Endovascular occlusion of wide-necked aneurysms with a new intracranial microstent (Neuroform) and detachable coils

OBJECTIVE: The long-term durability of the endovascular occlusion of cerebral aneurysms is one of the major factors limiting the more widespread use of this technique. Long-term occlusion of wide-necked aneurysms has improved with new assistive devices that seem to improve aneurysm occlusion while protecting the parent vessel. We report the use of a new intracranial stent--the Neuroform microstent--in the treatment of patients with wide-necked cerebral aneurysms. METHODS: Patients identified as harboring wide-necked intracranial aneurysms were evaluated for stent-assisted coiling. After appropriate anticoagulation was performed, depending on whether the aneurysm was ruptured or unruptured, the Neuroform stent was delivered across the neck of the aneurysm and deployed with a coil pusher. After stent placement, standard coil occlusion of the aneurysm was achieved in the majority of cases. RESULTS: Fifty-six patients were identified as having wide-necked intracranial aneurysms suitable for stent-assisted coiling. A total of 49 aneurysms in 48 patients were treated with this procedure. In eight cases, stent deployment failed. Forty-one of the aneurysms were initially stented, followed by coil placement. Six aneurysms were stented only, and one aneurysm was initially coiled, followed by stent placement. There were five deaths (8.9%), one of which occurred secondary to a stroke after the procedure (1.8%). Four patients (7%) experienced thromboembolic events, three of which were considered to have been secondary to the procedure (5.3%). In addition, there were two femoral pseudoaneurysms. The overall complication rate was 10.7%. Five patients were available for follow-up angiographic evaluation, and their cases are discussed. CONCLUSION: Intracranial stenting may overcome important technical limitations in current endovascular therapy by improving the occlusion of wide-necked aneurysms while protecting the parent vessel.     

Contralateral vertebral approach for stenting and coil embolization of a large, thrombosed vertebral-posterior inferior cerebellar artery aneurysm. Case report

The authors report the successful staged stenting and coil embolization of a large vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm using the contralateral VA for access. A 67-year-old woman presented with a large ruptured VA-PICA aneurysm. Initial attempts to stent the wide-necked aneurysm from the ipsilateral side failed, so coil embolization of the dome was performed. During a second endovascular session, the aneurysm neck was successfully stented from the contralateral VA into the PICA. Six weeks later, coils were inserted into the aneurysm from the ipsilateral side. The coil result was stable at the 3-month follow-up examination.     

Combined endovascular stent implantation and coil embolization for the treatment of a vertebro-basilar fusiform aneurysm: technical case report

We describe a case of the combined application of endovascular stent implantation and Guglielmi detachable coil packing for the treatment of a vertebro-basilar fusiform aneurysm and review the literature on stent placement to treat cerebral aneurysms. A 70-year-old female presented with an acute headache from subarachnoid hemorrhage. A fusiform aneurysm with a broad-based neck and dome, measuring 15 mm, involving the union of the vertebral arteries and the proximal basilar artery was demonstrated on cerebral angiography. The aneurysm was judged to be inoperable and treated conservatively. Twelve days later the patient was transferred to our hospital for endovascular therapy. An intravascular stent (MultiLink) was placed across the base of the aneurysm through the right vertebral artery. After this, coil placement in the aneurysm around the stent was performed via a microcatheter guided from the left vertebral artery. After that a microcatheter was guided from the right vertebral artery through the interstices of the stent into the aneurysm, and additional coils were placed. Final angiography showed subtotal occlusion of the aneurysm and excellent blood flow of the parent artery through the stent. There were no new neurological deficits. Neither rerupture nor ischemic event has occurred. The use of stents provides another treatment for managing the difficult entity of intracranial aneurysms.     

Emerging concepts in the treatment of intracranial aneurysms: stents, coated coils, and liquid embolic agents

Endovascular techniques for the treatment of intracranial aneurysms are rapidly evolving. Modifications of more traditional coils have been introduced. Such modifications include newer coils coated with various polymers to increase both coil thrombogenicity and degree of aneurysm packing. In addition, newer coil designs aimed at improving the conformability of the coil to the aneurysm have been used with promising preliminary results. The availability of a newer generation of stents specifically designed for intracranial navigation allows for more effective treatment of aneurysms with wide necks, which usually have been considered unsuitable for optimal endovascular treatment. Endovascular alternatives to coil embolization, such as liquid embolic materials, also have been explored for the treatment of intracranial aneurysms, with varying results. We summarize the rationale for use of these newer devices and early clinical experiences. Areas of current research and future directions of endovascular aneurysm treatment also are discussed.     

Review of endovascular stent‐assisted embolization for management of intracranial aneurysms

Objective: This was a retrospective review of the results using stent‐assisted coil embolization for management of intracranial aneurysms. Methods: The records of seven patients treated with stent‐assisted Gugliemi detachable coil (GDC) embolization were retrieved from the authors’ prospectively maintained database. The clinical presentation, site and type of aneurysms, treatment procedure and complications, and outcome of these identified cases were reviewed. Results: Between January 2002 and May 2004, seven patients with intracranial aneurysms, four of which were ruptured, were treated by stent‐assisted GDC embolization. Four aneurysms were located at the anterior circulation and three were at the posterior circulation. The indications for stent use were: giant aneurysm (>2.5 cm), dissecting pseudo‐aneurysm, broad‐necked aneurysm and the need for preservation of important parent arteries or branches. Concerning the technical aspect, all except one had successful stent deployment. One stent dislodged after apparent successful deployment. GDC embolization was continued and the aneurysm was partially occluded. More than 90% occlusion of aneurysm sac was achieved in six aneurysms. Intraoperative complications included over‐coagulation, failure in stent deployment, displacement of stent, coil entrapment and thromboembolism. One patient had added focal neurological deficit after the procedure, and one became vegetative due to an unrelated cause. The patient in whom the stent was dislodged suffered another subarachnoid haemorrhage 4 months later and died. Conclusion: Percutaneous intracranial stent is a new and useful device to assist embolization of cerebral aneurysms that were previously not amenable to endovascular therapy. These preliminary results suggest that this procedure could achieve satisfactory outcomes without significant complications.     

颅内动脉瘤囊内栓塞治疗中并发症的分析

目的 探讨颅内动脉瘤囊内治疗中并发症的发生原因及预防和处理的方法。方法 用可控性弹簧圈栓塞治疗的动脉瘤120例（125个）,其中22例（23个动脉瘤）发生并发症25例次（包括动脉瘤破裂、载瘤动脉血栓形成或其它原因所致的闭塞以及弹簧罪状脱出动脉瘤）,对其发生的原因及预防和治疗方法进行了回顾性分析。结果 22例出现并发症的动脉瘤患者中,动脉瘤破裂出血9例次,过度栓塞7例次,弹簧圈脱出7例次,血栓形成2例次,因并发症而死亡4例（3.33%),永久性神经功能障碍2例（1.67%);一过性神经功能障碍4例（3.33%)。栓塞技术、术中判断和处理的正确与否、动脉瘤和载瘤动脉的特点以及栓塞材料与并发症的发生和结局相关。结论 栓塞技术的提高,动脉瘤和载瘤动脉解剖的深入理解,术中发生情况的正确处理、栓塞材料的改进,有助于降低并发症的发生率改善其预后。     

A case of a vertebral artery fusiform aneurysm treated with stent assisted coil embolization: technique to prevent coil migration

Placement of a stent over the aneurysm neck and secondary coil embolization prevents coil migration and allows attenuated packing of the coils. However, during the course of the embolization, coils project over and obscure the parent vessel. Here we report a novel technique for endovascular parent vessel reconstruction with aneurysm embolization. A 73-year-old male had an incidental fusiform aneurysm at the V4 segment of the left vertebral artery. The size of the aneurysm increased from 7 mm to 8 mm in diameter. Since the right vertebral artery was hypoplastic, endovascular parent vessel reconstruction with coil embolization was performed. A flexible balloon-expandable coronary stent was navigated to the lesion and deployed successfully followed by coil embolization using a microcatheter through the stent. The balloon was inflated intermittently during coil insertion avoiding coil migration to inside the stent. Furthermore, the angle of the image intensifier was manipulated to visualize the inside of the stent. Postoperative course was uneventful and follow-up MRI three moths later demonstrated obliteration of the aneurysm and patency of the parent artery. This technique provides a practical treatment strategy for the management of a circumferential aneurysm.     

支架结合电解可脱弹簧圈治疗宽颈后交通动脉瘤的初步体会

目的 总结血管内支架结合电解可脱弹簧圈(Guglielmi detachable coil,GDC)治疗宽颈后交通动脉瘤的临床体会。方法 32例宽颈后交通动脉瘤,均先植入冠脉支架覆盖动脉瘤颈,再将微导管通过支架网孔超选进入动脉瘤腔,填塞GDC。结果 32例患者,动脉瘤完全填塞26例,90％以上填塞4例,60～70％填塞2例。所有载瘤动脉通畅,临床效果优良。结论 血管内支架结合GDC是治疗宽颈后交通动脉瘤的有效方法,长期疗效有待进一步随访。