EZ Stent Research Articles

Development of a bioresorbable self-expanding microstent for interventional applications - an innovative approach for stent-assisted coiling.

Objectives Stent-assisted coiling prevents coil migration in broad-based intracranial aneurysms. So far, only permanent metal stents are approved for intracranial use. Bioresorbable stents allow a new therapeutic approach that may prevent the need for lifelong anticoagulation. We developed a neurovascular bioresorbable microstent (NBRS) and compared it in vitro to the commercial Neuroform EZ stent. Materials and Methods The self-expanding NBRS design is oriented on the Neuroform EZ stent. Poly L-lactic acid (PLLA) was used to manufacture semi-finished products in a dipping process. For the compensation of the inferior material properties of PLLA, design adjustments were made. The NBRS were cut by means of femtosecond (fs) laser and were morphologically and mechanically compared in vitro to the Neuroform EZ stent. In vitro implantation of an NBRS was performed using a complex patient-specific 3D-printed aneurysm model. In addition, an in vitro coiling procedure to assess the stent’s ability to support a coil package was conducted. Results The NBRS could be reproducibly manufactured and had high quality regarding surface morphology. The radial force at the indicated vessel diameter of 3.0 mm was slightly higher for the Neuroform EZ stent compared to the NBRS. The self-expansion ability of the NBRS could be proven. The kink behavior of the NBRS was comparable to that of the Neuroform EZ stent, so no vessel lumen size reduction is expected. The stents showed identical deformation under local compression of 25 % based on the initial diameter, resulting in maximum forces of 24 ± 5 mN (Neuroform EZ) and 8 ± 2 mN (NBRS). The implanted NBRS expanded uniformly, and proper vessel wall adaptation was observed. The NBRS has the ability to retain a coil package. Conclusion This study reported a reproducible manufacturing process for the developed NBRS as well as mechanical and morphological in vitro tests. Furthermore, successful NBRS implantation into a complex patient-specific vessel model was presented as proof of concept. The promising results of this study, also considering the commercial Neuroform EZ stent, support the idea of fully biodegradable microstents for intracranial aneurysm treatment. Key Points

Short-term efficacy of stenting as a rescue therapy for acute atherosclerotic occlusion in anterior cerebral circulation.

The study aimed to explore the efficacy and safety of the Neuroform EZ stent in treating acute anterior circulation large artery occlusion. The clinical data of 42 consecutive patients with acute anterior circulation large atherosclerotic occlusion who were treated with the Neuroform EZ stent from January 2018 to August 2019 in our stroke care center, including baseline characteristics, images, therapeutic condition, and follow-up data were retrospectively analyzed. There were 42 mechanical thrombectomy (MT) failure cases of intracranial atherosclerotic stenosis with rescue Neuroform EZ stent implantation, of which 78.6% (33/42) had a good prognosis and 88.1% (37/42) showed no re-stenosis at follow-up. The average time from puncture to recanalization is 79.50 ± 14.19 min. The successful rate of intraoperative stent release is 97.6%, while there is one case of stent displacement, three cases of thrombus escape, and six cases of hemorrhage. Rescue therapy of the Neuroform EZ stent for acute anterior circulation large atherosclerotic occlusion can archive good short-term imaging and clinical results, while long-term follow-up is still needed to verify.

Bifurcated Aneurysm Location Predicts In-Stent Stenosis After Neuroform-EZ Stent-Assisted Coiling for Intracranial Aneurysm.

Background and PurposeThe Neuroform EZ stent system (Boston Scientific Corporation, Fremont, CA, United States) is a fourth-generation intracranial aneurysm stent designed specifically for the cerebrovasculature to support aneurysm treatment. In this study, we analyzed our consecutive series of patients with aneurysm treated with the Neuroform EZ stent, with special attention to the occurrence of in-stent stenosis (ISS).MethodsA retrospective review of our center's electronic database was conducted to identify all patients with intracranial aneurysms who underwent aneurysm treatment with the Neuroform EZ stent between January 2016 and October 2018. Patients with at least one digital subtraction angiography (DSA) follow-up in our hospital were enrolled in this study. In-stent stenosis (ISS) was graded as mild (<2–5%), moderate (25–50%), or severe (>50%).ResultsThe study included 114 patients (78 women, 68.4%; median age 57.2 ± 9 years) with a total of 116 aneurysms. Of the 116 lesions, 20 were identified with ISS (17.2%) at a mean follow-up of 6.9 ± 1.7 months, and ISS was mild in 30% (6/20), moderate in 50% (10/20), and severe in 20% (4/20). No patients were symptomatic or required further intervention. Patients who developed ISS were younger than those without ISS (52.6 ± 7.8 vs. 57.9 ± 9; p = 0.016). The proportion of aneurysms located at the artery bifurcation was significantly higher in patients with stenosis than located at the sidewall artery (37.9 vs. 10.3%; p = 0.002). In the multivariable analysis, the patients' age (OR = 0.94; 95% CI 0.88–0.998; p = 0.02) and bifurcated aneurysm location (OR = 4.59; 95% CI 1.54–13.67; p = 0.006) were independent predictors of ISS.ConclusionsIn this retrospective study, the incidence of ISS after Neuroform EZ stent placement was 17.2%, and all the ISS cases were asymptomatic. Patients with younger age and bifurcated aneurysm location are more likely to develop ISS. Although Neuroform EZ stent is particularly suitable for bifurcated aneurysms, the ISS for this location should be focused upon.

Overlapping Stents-Assisted Coiling for Vertebral Artery Dissecting Aneurysm : LVIS Stent within Neuroform EZ Stent.

ObjectiveTo evaluate the safety and efficacy of an overlapped stenting-assisted coiling technique in treating vertebral artery dissecting aneurysm (VADA) via Low-profile Visualized Intraluminal Support (LVIS) stent-within-Neuroform EZ stent. MethodsFrom January 2017 to June 2019, 18 consecutive patients with VADAs (ruptured : unruptured=5 : 13) were treated with the overlapping stents assisted-coiling technique in our center. The overlapping manner was a Neuroform EZ stent being deployed first, followed by LVIS stents placement using the ‘shelf’ technique. The patients’ clinical characteristics, technical feasibility and safety, and immediate and follow-up angiographic results were retrospectively reviewed. ResultsSeventeen (94.4%) procedures were technically successful with an exact deployment of the stents and patent parent or perforator arteries. The immediate angiographies after procedure confirmed Raymond class I, II, and III occlusion of VADAs were in 12 (66.7%), two (11.1%), and four cases (22.2%), respectively. Post-procedural complications developed in one patient (5.6%) with minor brainstem infarctions, which resulted from an in-stent thrombosis during the procedure. Angiographic follow-up at 5.7 months (range 3 to 9 months) demonstrated Raymond class I and II occlusion were in all cases (100%). The modified Rankin Scale scores at 21.3 months (range 15 to 42 months) 0–2 in 17 cases (94.4%) and three in one case (5.6%). ConclusionOverlapping stents via LVIS stent-within-Neuroform EZ stent combined with coiling is safe and effective for patients with VADA in the midterm results.

Application of the Neuroform Atlas Stent in Intracranial Aneurysms: Current Status.

The Neuroform Atlas stent (NAS) is the successor of the Neuroform EZ stent. The NAS is compatible with a low-profile 0.0165-inch microcatheter and is soft enough to pass through small and highly tortuous vessels. The NAS can be used in treating intracranial aneurysms at almost all locations, and its use is becoming increasingly common. However, there has not yet been a complete review of NAS applications. Therefore, we performed this review, which addresses several aspects of the NAS, mainly including its characteristics, clinical trials of its application in treating aneurysms, deployment techniques for the device, the prognosis and complications of its application in treating aneurysms, and antiplatelet requirements associated with its use. Based on the evidence reviewed here, as well as our experience, we found that the NAS is a promising device for treating intracranial aneurysms, especially complex and distal aneurysms. This stent can also be used as a powerful tool to assist in rescuing coil migration, completing dual-stent reconstruction, and coiling aneurysms via a transcirculation approach. The device may require antiplatelet therapy at a lower dose and over a shorter period than other stents. The deployment of the NAS to assist in aneurysm coiling can yield good clinical outcomes and an acceptable rate of complications. Thus, the NAS is a promising device.

The preliminary study of Neuroform EZ stent in the treatment of severe intracranial atherosclerotic stenosis

Objective: To evaluate the safety and clinical efficacy of Neuroform EZ stent in the treatment of severe intracranial atherosclerotic stenosis (ICAS). Methods: A total of 36 patients with severe ICAS receiving Neuroform EZ stent angioplasty were retrospectively analyzed at Beijing Anzhen Hospital from July 2018 to January 2020. Digital subtraction angiography (DSA) before endovascular intervention confirmed the diagnosis. Follow-up information was reviewed by neurologists at 30 days and 6 months after the procedure. The primary endpoints were transient ischemic attack (TIA), ischemic or hemorrhagic stroke and death caused by any reason within 30 days. Results: The overall technical success rate was 100%. The median stenosis rate was reduced from 93.6%±4.5% to 18.8%±11.2% (t=37.36,P<0.001).Primary endpoint event was not reported. During follow-up, one patient developed TIA and no death or ischemic stroke was observed. No in-stent restenosis at six months occurred. Conclusion: Neuroform EZ stent is safe and effective in patients with severe ICAS. However, perspective studies need to be operated for further validation via long-term follow-up.

The safety and efficacy of the Neuroform EZ stent for the treatment of symptomatic atherosclerotic stenosis in the middle cerebral artery

ObjectiveTo evaluate the safety and efficacy of Neuroform EZ stent placement for patients with symptomatic atherosclerotic stenosis of the middle cerebral artery (MCA). MethodWe retrospectively reviewed the clinical data of 70 patients (36 males and 34 females; mean age: 62.5 ± 1.25 years) with symptomatic atherosclerotic stenosis of the MCA who underwent Neuroform EZ stent insertion between January 2018 and June 2020. We reviewed the clinical data of each patient so that we could evaluate outcomes and angiographic findings at follow-up. ResultsThe technical success rate for the 70 patients was 100%. The mean rate of stenosis improved from 82.6 ± 6.5% (pre-stenting) to 21.11 ± 2.6% (post-stenting). During the post-stenting follow-up period, the 1-year frequencies of stroke, transient ischemic attack, and death, were all 0%. 42 patients were reviewed in hospital by DSA or CTA. Of the patients undergoing DSA or CTA review, four patients were found to have in-stent restenosis. ConclusionOur analysis indicates that the Neuroform EZ stent represents a valuable endovascular treatment option for patients with severe stenosis of the MCA. Additional studies are now needed to evaluate the long-term outcomes arising from the use of this technique.

Stent-assisted coiling of cerebral aneurysms: Head to head comparison between the Neuroform Atlas and EZ stents.

The Neuroform Atlas stent is thought to have features allowing for an improved stent delivery system. We aimed to provide a comparison of the Atlas and Neuroform EZ stents in patients treated with stent-assisted coiling. Seventy-seven aneurysms treated with the Atlas stent and 77 aneurysms with similar characteristics treated with the EZ stent were retrospectively compared. Outcomes included angiographic occlusion per the Raymond-Roy (RR) scale, recanalization, retreatment and procedural complications. With the Atlas stent, technical success was 100% and immediate RR1 occlusion was 81.8%. Follow-up RR1 was achieved in 83.7%. The recanalization rate was 7% and the retreatment rate was 4.6%. The complication rate was 6.5% (new neurological deficit in 1.3%). With the EZ stent, technical success was 96%, immediate RR1 occlusion was 67.6% and follow-up RR1 was 67.6%. The recanalization rate was 12.7% and the retreatment rate was 14.1%. The complication rate was 10.4% (new neurological deficit in 2.6%). The rate of immediate RR1 occlusion was significantly higher with the Atlas stent (p = 0.03), and the rate of follow-up RR1 was nonsignificantly higher with the Atlas stent (p = 0.08). The retreatment rate was significantly lower with the Atlas stent (p = 0.009). There were no significant differences in the rates of recanalization (p = 0.5) and complications (p = 0.6). Stent-assisted coiling with the Atlas stent is safe and effective and shows better immediate results as compared to the EZ stent, with improved overall follow-up outcomes.

Application of Neuroform EZ stent in the treatment of severe intracranial arterial stenosis with complex symptomatic

To assess the safety and efficacy of Neuroform EZ stent used in treatment of symptomatic complex severe intracranial atherosclerotic stenosis (ICAS). Clinical data of 18 patients with symptomatic complex severe ICAS undergoing Neuroform EZ stent angioplasty from January 2016 to December 2017 were retrospectively analyzed. All the lesions of the patients in this group were considered as complex ICAS, i.e. with severe tortuous access, long (>10 mm) or occlusive or bifurcation lesions, with concurrent aneurysms near the stenotic lesion. The primary outcome was defined as any stroke (including ischemic or hemorrhagic) or deaths from any cause after stenting procedure within 30 days. The secondary outcome was defined as successful revascularization and occurrence of >50% in-stent restenosis during the follow-up period. All the 18 patients achieved technical success (100%) and mean stenosis rate was reduced from 85%±7% to 18%±6%. Of the 18 patients included, the 30-day stroke or death was 5.6% (1/18), which presented as basal ganglia region infarction in a patient with tandem lesions on the left vertebral artery. There was no hemorrhagic and death complications that occurred in the patients of this group. One concurrent aneurysm was embolized with micro coil (stent assisted) by stages after 1 month. In this group 12 patients were followed up with digital subtraction angiography (DSA) after hospital discharge. The follow-up period ranged from 8 months to 26 months [mean: (16±8) months]．During the follow-up period 2 patients in the 12 patients (2/12, 16.7%) developed in-stent restenosis (ISR) confirmed by DSA, and one of them was symptomatic restenosis and restored unobstructed blood flow after balloon angioplasty. Neuroform EZ stent for the treatment of highly screened symptomatic complex severe ICAS is safe and effective. It has its advantages over traditional stent.

Neuroform EZ Stenting for Symptomatic Intracranial Artery Stenosis: 30 Days Outcomes in a High-Volume Stroke Center.

Objective: To test whether Neuroform EZ stent placement combined with the modified techniques in symptomatic severe intracranial stenosis (ICAS) would result in lower rates of peri-procedural complications of intracranial stenting.Methods: We retrospectively reviewed the clinical data from 71 consecutive patients who underwent Neuroform EZ stent placement combined with the modified techniques for symptomatic severe ICAS at our institute between January 2016 and October 2017. The primary outcomes were ipsi-lateral ischemic stroke, intra-cerebral hemorrhage, or death within 30 days after stenting. The secondary outcome was technical success.Results: The technical success rate was 100%. The mean pre and post-stent stenoses were 84.2% ± 9.1% (median 85%, IQR75% to 90%) and 16.9% ± 10.2 % (median 15%, IQR 10% to 25%). The frequency of ipsi-lateral stroke, intra-cerebral hemorrhage, or death within 30 days was 0%.Conclusions: The combined use of Neuroform EZ stent placement and the modified techniques for symptomatic severe ICAS is technically feasible and safe, with very low peri-procedural complications. Further studies are required to assess the long-term results of this approach.

Weighing in on the Off-Label Use: Initial Experience of Neuroform EZ Stenting for Intracranial Arterial Stenosis in 45 Patients.

Background: The role of stenting for intracranial arterial stenosis (ICAS) has been increasingly debated due to negative results of randomized trials. Thus, exploration of more appropriate devices may hopefully shed light on the endovascular approach, especially for patients with recalcitrant ICAS related to a high risk of stroke. We sought to present and analyze the data of Neuroform EZ stenting for medically refractory ICAS in a single-center series.Materials and methods: Between November 2016 and January 2018, 45 consecutive patients treated with the Neuroform EZ stent were included in our retrospective study. Outcomes evaluation included successful procedure rate, vascular event within 30 days and recurrent stenosis for at least 6 months after the procedure.Results: The technical success rate was 100% for all 46 stenotic lesions. Mean pre-stent stenosis was 86.5 ± 8.7%, improving to 23.7 ± 18.1% after stenting. Combined procedure related vascular event rate was 2.2% (n = 1) within 30 days after the procedure. No in-stent restenosis was observed during an average follow-up period of 7.3 months.Conclusion: The Neuroform EZ stent system could serve as an off-label but promising optional device for ICAS stenting in a carefully selected subgroup of patients. Further longer-term clinical follow-up is mandatory to validate our initial results.

Preliminary experience with the application of Neuroform EZ stent for Y stent assisted coiling in the treatment of wide necked bifurcation aneurysm

Objective To evaluate the clinical effects and advantages of Neuroform EZ in constructing Y configured stent in the treatment of wide necked bifurcation aneurysm (WNBA). Methods Retrospective data was retracted regarding 6 cases of WNBA treated with Neuroform EZ in a Y configuration from October 2016 to March 2017 at Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University. Intraoperative DSA was performed in all cases and immediate results of embolization were assessed based on Raymond scale. Clinical follow-up was conducted at 30 days post surgery based on modified Rankin scale. Results The success rate of operation in 6 patients was 100% without surgery-related complications. Intraoperative DSA indicated complete embolization in 6 aneurysms which were classified as grade Ⅰ according to Raymond scale. Postoperative cerebral infarction occurred in 2 cases including 1 reporting symptomatic relief following fluid infusion and heparin anticoagulant therapy before discharge and the other undergoing heparin anticoagulant therapy and developing no neurological deficits at discharge. All patients had the mRS score of 0-1 assessed at the follow-up 30 days post surgery. Conclusion Y-configuration double-stent-assisted coiling, using either 2 Neuroform EZ stents or 1 EZ and some other stent, could be important and effective in treatment of WNBA.But the long-term curative effect remains to be further research. Key words: Intracranial aneurysm; Embolization, therapeutic; Stents; Treatment outcome; Wide necked bifurcation aneurysm

Use of self-expanding stents for better intracranial flow diverter wall apposition.

Background Flow diverter (FD) malapposition is associated with stroke-related complications. We document the use of self-expanding nitinol stents to remove/reduce the ledge of a FD deployed for aneurysm treatment. Methods We identified five patients who were treated with the Pipeline embolization device (PED) in conjunction with a Neuroform EZ stent for inadequate wall apposition of the ends of the FD at our institution between May 2014 and July 2015. Among other parameters, angiographic results, cone-beam computed tomography assessment of wall apposition and patient clinical outcome were evaluated. Results Incomplete device end apposition was seen in three cases, and precarious positioning of the distal end of the PED over the aneurysm neck was seen in two cases. In all five cases, successful treatment with good wall apposition and proper pinning of the PED distal edge was achieved using an additional Neuroform EZ stent. Appropriate aneurysm neck coverage and flow stagnation was seen in all cases. The combination of high radial outward force and open-cell design permits the Neuroform EZ stent to jail the malappositioned edges of the FD while maintaining good vessel-wall apposition itself and prevent migration of the PED. Short-term follow-up angiography showed device patency and complete aneurysm obliteration in all cases. Conclusions Preliminary results of this small case series suggest that the Neuroform EZ stent allows for effective treatment of FD malapposition in selected patients amenable for this endovascular approach. Long-term and larger cohort studies are needed to validate these results.

The Interference Phenomenon of Microcatheters in the Jailing Treatment for Internal Carotid Artery Side Wall Aneurysms with an Open Cell Stent System.

ObjectiveExcelsior XT-27 (Stryker Neurovascular, Fremont, CA, USA) or Rebar 27 (eV3 Covidien, Irvine, CA, USA) microcatheters have recently been used to overcome the limitations of the Renegade Hi-Flo microcatheter such as interference between two microcatheters (one for stent delivery and the other for cerebral aneurysm coiling) during the jailing technique. We evaluated differences and influential factors related to the interference phenomenon according to these two microcatheters group.Materials and MethodsBetween June 2011 and September 2013, the jailing technique was applied to 94 internal cerebral artery (ICA) aneurysms. The jailing technique with the Neuroform EZ stent system was performed using Renegade (n = 22), Rebar (n = 35), and XT-27 microcatheters (n = 37). In the Renegade Hi-Flo microcatheter group, the jailing technique was successful in 19/22 patients (86.4%) and interference between the two microcatheters occurred in 6/21 patients (28.6%). In the Rebar and XT-27 microcatheter group, the jailing technique was successful in 71/72 patients (98.6%) and interference between the two microcatheters occurred in 1/72 patients (1.4%).ResultsThere was a significant difference in the interference between the two delivered microcatheters group (p-value < 0.000) and the carotid siphon angle (p-value: 0.004) in the univariate analysis. In the multiple logistic regression analysis, the Rebar and XT-27 microcatheter group (odds ratio [OD] [95% confidence interval (CI)]; 31.277 [3.138-311.729], p-value: 0.003) and the carotid siphon angle (OD [95%CI]; 0.959 [0.922-0.997], p-value: 0.035) were found to be influential factors in the interference phenomenon.ConclusionThe Rebar 27 and XT-27 microcatheters were more successful and exhibited less interference between the two microcatheters than the Renegade Hi-Flo microcatheter.

Endovascular stenting for treatment of mycotic intracranial aneurysms

Mycotic intracranial aneurysms (MIA) are a rare form of cerebrovascular pathology for which obliteration must be undertaken when they present with rupture or fail to respond to antibiotic therapy. Intracranial stents provide the unique ability to simultaneously preserve parent vessel integrity while obliterating the aneurysmal sac, but their use for the treatment of MIA has only been reported in a few instances for proximally located lesions. We report a patient with a MIA treated with endovascular stenting and review the literature for similar cases. Three case reports of four MIA treated with either stent monotherapy or stent-assisted coil embolization were identified. The clinical and radiographic features of each case were detailed. A 35-year-old with bacterial endocarditis from Streptococcus mitis was diagnosed with a ruptured 3mm MIA of the pericallosal anterior cerebral artery after episodic diplopia. The MIA was successfully treated with stent-assisted coil embolization utilizing a Neuroform EZ stent (Stryker Neuroendovascular, Kalamazoo, MI, USA). Follow-up magnetic resonance angiography at 3months demonstrated complete aneurysm obliteration, and the patient was neurologically intact. In the literature, a M1 segment middle cerebral artery MIA, bilateral cavernous carotid MIA, and a unilateral cavernous carotid MIA were also successfully treated with Neuroform, Helistent (Hexacath, Rueil-Malmaison, France), and SILK (BALT Extrusion, Montmorency, France) stents, respectively. We present the first patient with a pericallosal MIA treated with stent-assisted coil embolization. Proper treatment of the causative organism with antibiotics minimizes the risk of infectious seeding of the stent. Intracranial stenting may be safely and effectively utilized to treat select cases of MIA.

Jailing Technique Using a Catheter-based Open-cell Stent System in Internal Carotid Artery Sidewall Aneurysms Unfeasible to Simple Coiling

ObjectiveAn open cell stent system may offer better apposition of cell struts to vessel wall than a closed cell stent system in acute vasculature. The purpose of this study was to evaluate the feasibility of coiling using the jailing technique with the Neuroform EZ stent system.MethodsThe jailing technique using the open-cell stent system of the Neuroform EZ stent was planned in 22 consecutive patients with 22 cerebral aneurysms. We retrospectively evaluated the technical success of the jailing technique and the occurrence of interference between two microcatheters as well as the factors influencing this interference.ResultsThe jailing technique was successful in 19/22 patients (86.4%), and interference between two microcatheters occurred in 6/21 (28.6%). The jailing technique failed in 3/22 patients, with problems that included failure of the stent delivery system to advance into the positioned microcatheter in one, interference between the microcatheters during the advancement of the stent delivery system in one, and failure of microcatheter insertion into the aneurysm sac in the remaining patient. Interference between the two microcatheters developed during the advance of the stent delivery system into the positioned microcatheter in all cases. One factor that influences interference between two microcatheters more than expected by chance is the carotid siphon angle (p = 0.019).ConclusionThe acuteness of the carotid siphon angle influences the interference between two microcatheters. Therefore, the jailing technique using the Neuroform EZ stent should be performed carefully in cerebral aneurysms with an acute carotid siphon angle because the procedure may possibly fail.

Neuroform-EZ Stent Modification for Facilitated Delivery during Intracranial Aneurysm Embosurgery

The Neuroform EZ Stent System is a fourth generation intracranial aneurysm stent that utilizes an integrated navigation guidewire. While designed to facilitate stent delivery, the guidewire can rarely impede proper positioning of the stent. In this technical case report, severing the guidewire from the stent delivery system with surgical scissors was required for successful stent implantation.

Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction

ObjectLittle is known about how much protection a flow diversion stent provides to a non-thrombosed aneurysm without the adjunctive use of coils.MethodsA three-dimensional anatomically realistic computation aneurysm model was created...

Double‐Barrel Stent‐Assisted Coiling of a Basilar Artery Fenestration Aneurysm

Basilar artery fenestration aneurysms are rare aneurysms, posing unique challenges for endovascular treatment. We report a case of successful treatment of a wide-necked basilar artery fenestration aneurysm with a novel double-barrel stent-assisted coiling technique. A 50-year-old woman presented with headaches. Evaluation revealed an unruptured 7-mm broad-based basilar artery fenestration aneurysm that incorporated both limbs of the basilar fenestration and both distal vertebral arteries. A 4.5 mm × 22 mm Enterprise stent (Codman Neurovascular, Raynham, MA, USA) was deployed from the right limb of the basilar fenestration into the right distal vertebral artery. Similarly, a 2.5 mm × 20 mm Neuroform EZ stent (Boston Scientific, Natick, MA, USA) was placed from the left limb of the basilar fenestration into the left distal vertebral artery. Following stent deployment, the aneurysm was treated with coil-embolization through a jailed microcatheter. In the case presented, a double-barrel stent configuration enabled dense coil embolization of the aneurysm as well as preservation of both basilar fenestration limbs and both distal vertebral arteries.

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

PurposeStent-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 MethodsSeventeen 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.ResultsIn 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.ConclusionThe 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.