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Summary

We describe a modified stent-assisted coiling technique, named the semi-deployment technique, in the endovascular treatment of wide-neck aneurysms. Thirty-one consecutive patients with 31 wide-necked or fusiform intracranial aneurysms were treated with the semi-deployment technique. The technical feasibility of the procedure, procedure-related complications, angiographic results, clinical outcome and follow-up angiography were evaluated. In every case, the semi-deployment technique was successfully deployed. Immediate angiography demonstrated complete occlusion in 24 cases (77.4%), neck remnant in four cases (12.9%), and incomplete occlusion in three cases (9.7%). Procedural-related morbidity occurred in one patient (3.2%) but no procedural-related mortality. A favorable clinical outcome (Modified Ran-kin Scale score 0-2) was observed in 90.3% of the patients (average follow-up time, 23.1 months). No rehemorrhage of treated aneurysms occurred. Angiography follow-up was obtained in 22 cases (71.0 %). Three aneurysms (13.6 % of the follow-up angiograms) demonstrated recanalization. No delayed coil or stent migration was found. One patient had in-stent stenosis as a delayed complication. We found that the semi-deployment technique was helpful in the treatment of wide-neck aneurysms.

Summary

Endovascular treatment of intracranial aneurysms by coiling has become an accepted alternative to surgical clipping1. In cases of wide-necked and sidewall aneurysms, selective embolization is difficult because of the risk of coil protrusion into the parent vessel. The use of three-dimensional coils, stents2, and balloon remodeling have all aided the attempt to adequately manage such lesions. However, compared with sidewall aneurysms, bifurcation aneurysms are more challenging from an endovascular standpoint. Because of their specific anatomy and hemodynamics, the tendency to recur and rerupture is higher. Several authors have reported successful treatment of these complex and wide-necked bifurcation aneurysms by using Y-configured dual stent-assisted coil embolization3,4, the double microcatheter technique5, a more compliant balloon remodeling technique6, the TriSpan neck-bridge device7, or the waffle cone technique8. We describe two cases of wide-necked bifurcation aneurysms in which the waffle cone technique was used for coil embolization. The waffle cone technique was first described in 2006; however, the small number of published cases and the lack of follow-up prevent one from assessing this technique's durability and the probability of recanalization. We report the cases of two patients harboring unruptured wide-necked bifurcation aneurysms that were treated and followed-up for six months.

Summary

We report a case of a 55-year-old man carrying two unruptured internal carotid artery (ICA) wide-neck aneurysms.

In the same session, the smaller aneurysm was treated by coils using the remodeling technique and the large aneurysm was treated by stent-assisted coil embolization. During the stent-assisted procedure for the large aneurysm, the microcatheter tip moved from the aneurysm into the parent artery causing a prolapse of some coil loops into the vessel lumen.

The distal part of the coil was tangled within the stent's struts, therefore, in order to introduce the entire coil, an attempt was made to withdraw the prolapsed loops of the coil within the microcatheter and concomitantly repositioning the microcatheter into the residual aneurysm neck through the stent struts. However this maneuver was unsuccessful.

An attempt to retrieve gently the coil also failed and the coil prematurely detached. For maintaining the patency of the arterial lumen and to reduce the embolic risk, a second stent was used to pin the free coil loops. The rescue stent was positioned within the coil loops and its deployment allowed a circumferential expansion of some loops around the stent perimeter while other loops were flattened against the wall of the artery. The parent artery remained patent at one-year follow-up angiographic study. No clinical complications were observed.

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.

Summary

Endovascular treatment of wide neck intracranial aneurysms is technically difficult and leads to less favorable treatment results and long term outcome. We participated in a multicenter prospective study to evaluate the safety and performance of a new self-expandable nitinol micro stent (Neuroform) in stent assisted coil occlusion of wide neck intracranial aneurysms. Eighteen patients were enrolled in the study in a single center. The anatomy of the target aneurysm and the parent vessel, technical details of the procedure, device functionality, anatomic and clinical results were evaluated. All enrolled aneurysms were either wide necked or showed an unfavorable neck-to-fundus ratio. In 16 out of 18 patients the Neuroform device allowed stent assisted coil occlusion of the aneurysm. The occlusion rate was 95% in eight patients and 100% in eight patients. The two failures were both due to anatomic reasons. Flexibility of the stent, behavior during deployment and subsequent ability to retain coils within the aneurysmal sac were considered as good as or better than the properties of previous balloon expandable stents. No device-related adverse events were encountered. Procedure-related clinical complications occurred in seven patients but caused no severe permanent neurological deficit. The Neuroform neurovascular stenting system is a safe and effective adjunct for the stent-assisted coil occlusion of wide necked intracranial aneurysms. The major advantages of this device are its self-expanding property and very high flexibility which allows safe navigation, easy sizing, as well as accurate positioning of the stent while providing sufficient bridging of the aneurysm neck for subsequent coil placement.

Introduction: Techniques for coil embolization of wide-neck cerebral aneurysms include the use of stents and temporary occlusion with compliant non-detachable balloons to safely allow dense packing of the aneurysm lumen with detachable coils. We describe the use of a new balloon device for assisting in wide-neck aneurysm coil treatment. Methods: A single institution neuroendovascular database was accessed to identify cases in which the Ascent balloon (Codman Neurovascular, Raynham, MA, USA) was used for aneurysm coil embolization. Clinical, demographic, and angiographic data were obtained through chart review. Results: Eleven cerebral aneurysm cases were treated using the Ascent balloon during the first 12-month period that the new device was available at our institution. Three of the patients presented with ruptured aneurysms. All aneurysms were large (maximum diameter 6 mm or greater), with an average maximum diameter of 9.4 mm, and an average neck diameter of 5.5 mm. Complete occlusion with coil embolization (Raymond class I) was achieved in all cases. The Ascent balloon was successfully positioned across the neck of the aneurysm in nine patients. Conclusion: This initial experience demonstrates the feasibility and immediate outcomes of the coaxial dual-lumen design Ascent balloon catheter used as an assistive device in coil embolization of wide-neck cerebral aneurysms. This device contributes to the growing number of assistive devices for the treatment of complex cerebral aneurysms.

Summary

In this paper, we report five cases with acutely ruptured wide-necked aneurysms, which were treated with coil embolization using a balloon or stent-assisted technique. Balloon-assisted coil embolization using Equinox balloon, Commodore balloon, and Hyperform balloon were performed for four patients and stent-assisted coil embolization using BX velocity for one patient. We discuss problems of coil embolization for acutely ruptured wide-necked aneurysms with a balloon or stent-assisted technique.

Summary

The endovascular treatment of very small aneurysms (lesions less than 3 mm in maximum diameter) with wide necks remains a challenge for saccular embolization. We retrospectively analyzed our data using Neuroform stent-assisted coiling for very small supraclinoid aneurysms with wide neck to evaluate the feasibility and efficacy of endovascular treatment of these lesions.

We conducted a review of our experience and results of endovascular treatments in six patients with seven very small aneurysms. All aneurysms were located at the side wall of the supraclinoid segment of the ICA. They were ruptured in two patients and unruptured in four. The technique of stent-assisted coiling was used in all cases with coiling before stenting and additional coils after deployment of the stent in the same session.

All patients were successfully embolized with stent-assisted coiling. The coils were introduced into the lumen for subtotal occlusion in five aneurysms and for partial occlusion in two. During one to two years follow-up angiography, all aneurysms were completely occluded and no recurrence occurred. No complications were observed.

Endovascular stent-assisted coil embolization of supraclinoid very small aneurysms with wide necks is effective and feasible. Subtotal aneurysm occlusion might progress to total occlusion.

Purpose

The optimal management of geometrically complex aneurysms remains challenging. The aim of this retrospective study was to evaluate the safety and feasibility of branch-selective technique (BT) in wide-necked aneurysms with an acute angle branch incorporated into the sac.

Materials and Methods

Eight consecutive patients harboring wide-necked cerebral aneurysms with an incorporated, acute angle branch (mean, 30.4°) underwent coiling over an 18-month period. Dome-to-neck ratio ranged from 0.9 to 1.8 (mean, 1.2). Every procedure utilized BT, i.e., stent- or catheter-assisted coiling through the incorporated branch.

Results

Technical success was achieved in all cases. With the aim to avoid the risk of aneurysmal rupture during struggling intraaneurysmal wire navigation, a 'looping method' and retrograde approach of a preshaped 0.014' microcatheter (C or J) was used for branch access in five cases and a 'looping method' and antegrade approach in one case. In the remaining one, just the C-preshape was enough to directly enter the branch without intraaneurysmal wire navigation. Overall, stent-assisted coiling was performed in seven cases, while catheter-assisted coiling was undertaken in one. The only complication was thrombotic posterior inferior cerebellar artery occlusion in one case, which was recanalized after tirofiban infusion. New neurological deficits were not identified in any cases.

Conclusion

BT seems safe and feasible for wide-necked aneurysms with an acute angle branch incorporated into the sac. The looping method may offer safe access to the incorporated, acute angle branch and should be considered for replacement of the fearful intra-aneurysmal wire navigation.

Summary

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.

We present a case of stent-assisted coil embolization of a wide-necked renal artery aneurysm performed at our institution. The technique involved a stent being delivered over the neck of the aneurysm. Subsequently a catheter was placed into the aneurysm through the stent mesh and the aneurysm was then filled with detachable coils. Complete aneurysm occlusion was obtained and there was no evidence to suggest renal infarction on a follow-up contrast CT scan 6 months later. Our preliminary experience suggests that stent-assisted coil embolization of wide-necked renal artery aneurysms is a technically challenging but potentially effective renal-sparing endovascular approach.

Background:

Large wide-necked arterial bifurcation aneurysms present a unique challenge for endovascular coil embolization treatment. One technique described in the literature deploys a Neuroform stent into the neck of the aneurysm in the shape of a waffle-cone, thereby acting as a scaffold for the coil mass. This case series presents four patients with large wide-necked bifurcation aneurysms treated with the closed-cell Enterprise stent using the waffle-cone technique.

Case Description:

Four patients (59 ± 18 years of age) with large wide-necked arterial bifurcation aneurysms (three basilar apex and one MCA bifurcation) were treated with the waffle-cone technique using the Enterprise stent as a supporting device for stent-assisted coil embolization. Three of the patients presented with aneurysmal subarachnoid hemorrhage (Hunt-Hess 2-3; Fisher Grade 3-4). There was no procedural morbidity or mortality associated with treatment itself. One aneurysm was completely obliterated, and three had small residual necks. One patient developed an area of PCA infarct and visual field cut one month after the procedure and required recoiling of the residual neck. The flared ends of the Enterprise stent remodeled the aneurysm neck by conforming to the shape of the neck without any technical difficulty, resulting in a stable scaffold holding the coils into the aneurysm.

Conclusion:

The closed cell construction, flexibility, and flared ends of the Enterprise stent allow it to conform to the waffle-cone configuration and provide a stable scaffold for coil embolization of large wide-necked arterial bifurcation aneurysms. We have had excellent initial results using the Enterprise stent with the waffle-cone technique. However, this technique is higher risk than standard treatment methods and therefore should be reserved for large wide-necked bifurcation aneurysms where Y stenting is needed, but not possible, and surgical clip ligation is not an option.

Summary

We report a patient with a wide-necked aneurysm arising at the bifurcation of the right internal carotid artery and the persistent primitive trigeminal artery (PPTA) treated successfully by Matrix detachable coil occlusion and assisted by a Neuroform intracranial stent. First, a Neuroform self-expanding intracranial stent was delivered via a 5-F Guider Softtip XP and placed as desired, then the aneurysm dome was embolized with two Matrix detachable coils through the interstices of the stent. The aneurysm was 80% occluded angiographically and the parent artery was patent. DSA imaging six months after the procedure showed the aneurysm to be obliterated at angiography and the neck tissue thickness of the aneurysm to be increased, but the parent artery diameter was not impacted. We describe the case in detail and discuss our preliminary experience of using the Neuroform stent and Matrix detachable coils for the treatment of a PPTA wide-necked aneurysm.

A prospective study was performed to evaluate the efficacy of neurophysiological monitoring (NPM) techniques in the detection of ischemic changes that may be seen during endovascular treatment of cerebral aneurysms. Sixty three patients underwent NPM during first-stage endovascular treatment of cerebral aneurysms. The endovascular procedures included coil embolization (26 patients), balloon-remodeling coiling (16 patients), stent-assisted coiling (10 patients), balloon-stent-assisted coiling (9 patients), and balloon test occlusion (2 patients). NPM included electroencephalography, somatosensory evoked potentials, and brain stem auditory evoked potentials, depending on the location of the aneurysm and its associated vascular territory. NPM changes were seen in 3 (4.8%) patients and the procedures were altered immediately. No neurological changes were found postendovascularly. Ten patients demonstrated abnormal angiographic findings without concurrent NPM changes, of which 5 patients developed visual disturbance or hemiparesis. It is concluded that NPM is a valuable monitoring tool for endovascular treatment of cerebral aneurysms.

Summary

Endovascular treatment of ruptured intracranial aneurysms with detachable coils has proven a favorable alternative to surgical clipping. However, coiling has limitations in the treatment of complex or broad neck aneurysms because of possible coil prolapse or coil migration into the parent vessel and long-term angiographic recurrences. To achieve reconstruction of intracranial vessels with preservation of the parent artery, the use of stents has the greatest potential for assisted coil embolization. Three-dimensional coils and reconstructive techniques such as balloon-assisted remodeling may overcome these problems. But these methods had some drawbacks.

The Neuroform stent is the most recently developed endovascular stent with self-expandable and micro-delivery properties that are specially designed for the treatment of unruptured intracranial broad neck aneurysms.

Aim of the following working is to report a single center experience of stent-assisted coiling on ruptured intracranial aneurysms with assessment of its efficacy and safety, and follow-up findings.

Summary

To elucidate focal successive histological responses of the neck of wide-necked aneurysm after single stent implantation and stent-assisted coiling, an experimental wide-necked aneurysm model was surgically created in bilateral common carotid arteries of adult dogs. Balloon-expandable porous stents were positioned across the aneurysm necks on both sides. The aneurysm cavity of one side was additionally loosely coiled with Gugliemi detachable coils after stent implantation. The dogs were followed up with ultrasonography and angiography, then sacrificed at two days, one month, and one year and the aneurysm specimen was subjected to macro, micro, and electron microscopic observation. Stent implantation and coiling was successful in eight dogs. This investigation observed that single stent implantation slowed down the blood flow within the aneurysm, but barely induced thrombosis within the aneurysm. There was neointima formation over the stent mesh without thrombus within the aneurysm cavity, but it did not cover the whole aneurysm neck at one year. Aneurysms treated with stent-assisted coiling showed thrombosis within the aneurysms and neointima formation over the whole aneurysm orifice. These results suggest that the neointima could develop over bare stent filament without thrombus within the aneurysm cavity, coils could enhance thrombosis within the aneurysm cavity and facilitate neointima formation over the aneurysm orifice. Stent-assisted coiling may be an alternative option for the treatment of wide-necked aneurysms.

Summary

A 30-year-old man was referred in our department for treatment of a midbasilar trunk aneurysm. His presenting symptoms included headache and dizziness. A CT scan at another hospital showed no significant findings whereas a digital subtraction angiogram disclosed a dissecting aneurysm in the midbasilar trunk, and there was severe stenosis in the basilar artery. After discussion, we planned to use stent-assisted-coil embolization technique. During the procedure, a LEO stent (Balt, Montmorency, France) was implanted into the basilar artery across the aneurysm neck, but fearing acute basilar artery occlusion because of stent collapse or thrombus we did not fill coils into the aneurysm.

After the procedure, the completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. The patient awoke from general anaesthesia after the procedure and had no additional neurological symptoms, he was discharged three days later and used clopidogrel and aspirin for antiplatelet therapy. Six months later when he was admitted for a recheck, a DSA showed the basilar artery was occluded completely and the aneurysm had disappeared even though the patient remained neurologically normal.

Endovascular treatment of wide-necked aneurysms poses a challenge for the endovascular therapist. The Y-stent–assisted technique has been used for stent-assisted coil embolisation for wide-necked bifurcation aneurysms. This technique has been described for basilar tip aneurysms and middle cerebral artery bifurcation aneurysms using Neuroform and Enterprise stents. We report 2 cases of wide-necked bifurcation aneurysms that were treated with Y-stent–assisted coil embolisation using a new, fully retrievable and detachable intracranial stent (Solitaire AB™). We describe the advantages of a fully retrievable and detachable stent and its feasibility of forming a Y configuration.

Background:

To evaluate the safety and efficacy of stent-assisted coiling of ruptured intracranial wide-necked aneurysms in a setting of acute subarachnoid hemorrhage, without compromising on the antiplatelet regimen.

Methods:

Forty-two consecutive patients who underwent stent-assisted coiling for ruptured wide-necked intracranial aneurysms from August 2008 to May 2012 were studied. Demographic data like age, sex, Hunt & Hess grade, Fischer scale, and location, and size of the aneurysms were noted. Complications such as aneurysmal rupture, bleeding complications, thromboembolic events, etc. were documented. Also, 30-day and 1-year outcome was measured using modified Rankin scale (mRS).

Results:

Forty-four wide-necked aneurysms were treated in 42 patients with stent-assisted coiling from August 2008 to May 2012 in our institution, out of a total of 248 aneurysms treated endovascularly in the same period. All these patients presented with subarachnoid hemorrhage (SAH) with varying grades and were treated in the acute phase, i.e. within 1 week of the ictus. There were 24 males and 18 females in the age group ranging from 12 to 78 years, with a mean of 45 years. Technical success was achieved in 39 patients with complete angiographic cure (93%). Intraprocedural stent thrombosis was seen in two patients, which resolved with intra-arterial bolus of tirofiban, and both the patients did not have any neurological deficit. Rebleed occurred in two patients of which one patient succumbed.

Six patients required external ventricular drain because of worsening hydrocephalus on computed tomography (CT) scan with clinical deterioration. There was one death in our series due to rebleed. Three other patients died in a period of 1 month due to complications not related to the coiling procedure which include vasospasm, pulmonary embolism, and respiratory infection. All the patients were clinically followed up at 1 month, 3 months, 6 months, and 1 year. Also, angiographic follow- up was done at 1 year in 25 patients (72%). All the patients were maintained on clopidogrel 75 mg per day and ecospirin 150 mg per day for a period of 1 year and were advised to continue ecospirin 150 mg per day lifelong.

Conclusion:

Even in a setting of acute SAH, stent-assisted coiling can be an effective and safe treatment option with acceptable risks in experienced hands.

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.

ABSTRACT

Endovascular aneurysm repair (EVAR) is an important treatment option for abdominal aortic aneurysms, with lower perioperative morbidity and mortality rates than open surgical aneurysm repair. However, EVAR is associated with several unique complications that are not encountered with surgical repair such as endoleaks, graft migration, and renal artery occlusion. Preservation of the morbidity and mortality advantages of EVAR relies on the successful treatment of these complications by minimally invasive, endovascular approaches. Some of the techniques used to treat EVAR complications include balloon dilation and stenting, deployment of additional stent-graft pieces, coil embolization, and thrombolysis. Although the employment of these endovascular salvage techniques is common, data regarding their intermediate- to long-term efficacy is sparse, and further studies are needed to determine their efficacy in preventing conversion to open aneurysm repair and aneurysm rupture.

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.

As part of its Medical Technologies Evaluation Programme, the National Institute of Health and Clinical Excellence (NICE) invited the manufacturer, Covidien, to provide clinical and economic evidence for the evaluation of the Pipeline™ embolization device (PED) for the treatment of complex intracranial aneurysms. Cedar; a consortium between Cardiff and Vale University Health Board and Cardiff University, was commissioned to act as an External Assessment Centre (EAC) for NICE to independently critique the manufacturers’ submissions. This article gives an overview of the evidence provided, the findings of the EAC and the final guidance published by NICE.

The scope issued by NICE considered PED as the intervention in a patient population with complex unruptured intracranial aneurysms (IAs), specifically large/giant, wide-necked and fusiform aneurysms. The comparator treatments identified were stent-assisted coiling, parent vessel occlusion, neurosurgical techniques and conservative management. The manufacturer claimed that PED fulfils a currently unmet clinical need in the treatment of large or giant, wide-necked or fusiform IAs.

Thirteen studies were identified by the manufacturer as being relevant to the decision problem, with two of these included for data extraction. The EAC identified 16 studies as relevant, three of which had been published after the manufacturer’s search. Data extraction was carried out on these studies as, although many were low level research comprising of case reports and case series, they provided useful, pertinent safety and outcome data.

No relevant economic studies of the device were identified; therefore, a new economic model was designed by the manufacturer. The base-case scenario provided recognized the costs of PED to be higher than the costs for endovascular parent vessel occlusion, neurosurgical parent vessel occlusion, neurosurgical clipping and conservative management. However, PED was found to be cost saving compared with stent-assisted coiling, with a saving of £13,110 per patient.

Analysis of the clinical data suggested that treatment with PED has high rates of clinical success with high rates of aneurysm occlusion and acceptable adverse events for the patient population. Economic evidence suggested that the costs in the base-case for PED may have been underestimated, meaning that PED would only become cost saving in patients who would otherwise require treatment with 32 coils or more. NICE Medical Technologies Guidance MTG10, issued in May 2012, recommends the adoption of PED in selected patients within the UK National Health Service (NHS).

Summary

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.

Objective

To assess the feasibility, safety, and effectiveness of the balloon-assisted technique with HyperForm balloon in the endovascular treatment of wide-necked intracranial aneurysms.

Methods

A total of 34 patients with 34 wide-necked intracranial aneurysms were treated with endovascular coil embolization using balloon-assisted technique with Hyperform balloon. Twenty-nine aneurysms (85.3%) were located in the anterior circulation. The group of patients was comprised of 16 men and 18 women, aged 33 to 72 years (mean : 60.6 years). The size of aneurysms was in the range of 2.0 to 22.0 mm (mean 5.5 mm) and one of neck was 2.0 to 11.9 mm (mean 3.8 mm). The dome to neck ratio was ranged from 0.83 to 1.43 (1.15). Sixteen patients were treated for unruptured aneurysms and the remaining 18 presented with a subarachnoid hemorrhage.

Results

In the 34 aneurysms treated by the remodeling technique with HyperForm balloon, immediate angiographic results consisted of total occlusion in 31 cases (91.2%) and partial occlusion in three cases (8.8%). There were five procedure-related complications (14.7%), including two coil protrusions and three thromboembolisms; Except one patient, all were successfully resolved without permanent neurologic deficit. No new bleeding occurred during the follow-up. Twenty patients (59%) underwent angiographic follow-up from 2 to 33 months (mean 9.2 months) after treatment. Focal recanalization with coil compaction of the neck portion was observed in 5 cases (25%). Only one case showed major recanalization and underwent stent-assisted coil embolization.

Conclusion

The balloon-assisted technique with Hyperform balloon is a feasible, safe, and effective endovascular treatment of wide-necked cerebral aneurysms.