Rate Of Complete Aneurysm Occlusion Research Articles

Flow diverter treatment of posterior circulation aneurysms. A meta-analysis.

IntroductionTreatment of complex anterior circulation aneurysms with flow diverters (FDs) has become common practice in neurovascular centers. However, this treatment method for posterior circulation aneurysms (PCAs) still remains controversial.MethodsThrough searches for reports on the treatment of PCAs with FDs, we conducted a systematic review of the literature on its clinical efficacy and safety using random-effect binomial meta-analysis.ResultsWe included 14 studies, which reported on a total of 225 PCAs in 220 patients. Procedure-related good outcome rate was 79 % (95 % confidence interval (CI), 72–84), with significantly lower odds among patients with ruptured aneurysms and basilar artery aneurysms. Procedure-related mortality rate was 15 % (95 % CI 10–21), with significantly higher rates among patients with giant aneurysms and basilar artery aneurysms. The rate of complete aneurysm occlusion at 6-month digital subtraction angiography (DSA) was 84 %. Ischemic stroke rate was 11 %. Perforator infarction rate was 7 %. Postoperative subarachnoid hemorrhage (SAH) rate was 3 %. Intraparenchymal hemorrhage (IPH) rate was 4 %.ConclusionsFlow diverter treatment of PCAs is an effective method, which provides a high rate of complete occlusion at 6-month DSA. However, compared with anterior circulation aneurysms, patients with PCAs are at significantly higher risk of mortality, ischemic stroke and perforator infarction. Our findings indicate that, in most clinical centers, flow diverter treatment of PCAs should be conducted in carefully selected patients with poor natural history and no optimal treatment strategy. For ruptured and giant basilar artery aneurysms, there is still no good treatment option.

The Derivo Embolization Device, a Second-Generation Flow Diverter for the Treatment of Intracranial Aneurysms, Evaluated in an Elastase-Induced Aneurysm Model.

In recent years, flow diverters have provided a promising alternative to treat complex intracranial aneurysms. In this study, we compare a second-generation flow-diverting device (Derivo Embolization Device) with its prototype flow diverter, in the treatment of elastase-induced aneurysms in New Zealand white rabbits. The Derivo Embolization Device is a self-expanding stent consisting of 48 nitinol wires. The device was implanted across the necks of 17 elastase-induced aneurysms in New Zealand white rabbits. One additional device was implanted in the abdominal aorta of each animal covering the origin of lumbar arteries. Follow-up was performed after 3 months (n = 8) and 6 months (n = 9) under continuous double antiplatelet therapy. Statuses of angiographic and histological aneurysm occlusion as well as patency of branch arteries and neointimal growth were evaluated and compared with its prototype flow diverter. The Derivo Embolization Device provided advanced visibility and flexibility, which led to more accurate navigation and placement. Complete aneurysm occlusion rates were noted in 15 cases (88 %), respectively, compared with 5 cases (28 %) with the first-generation device (p = 0.001). Neointimal growth and diameter stenosis were significantly less with the Derivo Embolization Device and declining after 6 months follow-up in the abdominal aorta. Extreme device oversizing led to distal occlusion of the parent vessel in three cases. Covered branch arteries remained patent throughout the entire period of observation. The Derivo Embolization Device provides excellent occlusion of elastase-induced aneurysms while preserving branch arteries.

The Use of the Pipeline Embolization Device in the Management of Recurrent Previously Coiled Cerebral Aneurysms.

The biggest downside of cerebral aneurysm coiling is the high rates of recurrence and retreatments. With the increasing number of aneurysm recurrences after failed coiling procedures, the best retreatment strategy remains unknown. To assess the efficacy and safety of the Pipeline Embolization Device (PED) in the treatment of recurrent previously coiled aneurysms. Thirty-three patients who underwent treatment with the PED of a recurrent previously coiled aneurysm were retrospectively identified. Efficacy was assessed in terms of angiographic occlusion at the latest cerebral angiogram, recurrence and retreatment rates after PED placement, and clinical outcome at the latest follow-up. Safety was assessed by looking at the complications, morbidity, and mortality after PED treatment. The mean patient age was 53 years. The mean percent recurrence from coiling to PED placement was 34%. The mean time from coiling to PED placement was 40 months. PED treatment resulted in complete aneurysm occlusion in 76.7% of patients and near-complete aneurysm occlusion (≥90%) in 10%, for a total rate of complete and near-complete aneurysm occlusion of 86.7%. All patients, including those with incomplete aneurysm occlusion, had a significant reduction in aneurysm size. Two aneurysms required another retreatment after PED placement (6.2%). Ninety-seven percent of patients had a good clinical outcome. Complications were observed in 1 patient (3%), who suffered an intracerebral hemorrhage. There were no mortalities. The use of the PED in the management of recurrent, previously coiled aneurysms is safe and effective in achieving aneurysm occlusion.

Ultra-small diameter coils for treatment of intracranial aneurysms.

This study reports our initial clinical experience treating very small intracranial aneurysms using only Target® Nano™ coils. Retrospective angiographic and clinical analysis was performed on a non-randomized single arm registry of all intracranial aneurysms treated with only Target® Nano™ coils (1 mm and 1.5 mm diameter only) during a 12 month period at two academic hospitals. Fourteen patients with 14 intracranial aneurysms were treated. The maximum diameter of saccular aneurysms treated ranged from 1.5 to 3.5 mm; minimum aneurysm diameter was 1.1 to 2 mm. The immediate complete aneurysm occlusion rate was 86% (12/14), and a small residual within the aneurysm was seen in 14% (2/14) of cases. Packing density from coils ranged between 24% and 83% (mean 51%). The immediate complication rate was 0% (0/14). The angiographic/MR angiography follow-up period was 22 to 70 weeks (mean 37 weeks) with an overall complete occlusion rate of 9/11 (81%), recurrence in 18% (2/11), and lack of follow-up in three cases, two due to death during hospitalization and one procedure not yet due for imaging follow-up. Both patients who died presented with brain aneurysm ruptures prior to treatment. Both recurrences were retreated with repeat coiling procedures. Our initial results using only Target® Nano™ coils for the endovascular treatment of very small intracranial aneurysms have demonstrated initial good safety and efficacy profiles.

Impact of Endovascular Technique on Fluoroscopy Usage: Stent-Assisted Coiling versus Flow Diversion for Paraclinoid Internal Carotid Artery Aneurysms.

Flow diversion is increasingly being utilized for the treatment of internal carotid artery (ICA) aneurysms. The purpose of this study was to evaluate the impact of endovascular technique--flow diversion versus stent-assisted coiling (SAC) on fluoroscopy time in patients treated for wide-neck paraclinoid ICA aneurysms. A retrospective review identified the 20 most recent consecutive patients treated for wide-neck paraclinoid ICA aneurysms by flow diversion and SAC respectively. Fluoroscopy time, cumulative dose area-product (DAP), contrast usage, intra-procedural complications, and total procedure time were collected and compared between the two treatment techniques. Treatment groups were comparable in terms of demographics, contrast usage, and clinical and angiographic outcomes. Flow diversion was associated with a significant reduction in fluoroscopy time (52.0 minutes versus 77.4 minutes), and demonstrated a strong trend towards shorter total procedure time (172 minutes versus 202 minutes). Average patient radiation exposure as measured by DAP was lower in the flow diversion group, 13225 mGy(x)cm(2) versus 15124 mGy(x)cm(2), although this finding was not statistically significant. There was no significant difference in contrast usage between the two groups, 152 ml and 159 (flow diversion and SAC respectively). The rate of complete aneurysm occlusion was higher in the flow diversion group (80% versus 60%). Endovascular treatment of paraclinoid ICA aneurysms with flow diversion is associated with shorter fluoroscopy times compared to stent-assisted coiling. There is also a likely reduction in overall procedure time. These results should be considered when recommending a treatment course for patients with such lesions.

Experimental testing of a new generation of flow diverters in sidewall aneurysms in rabbits.

The development of new generation flow-diverting devices will improve the result of flow diversion in challenging aneurysms. The Flow-Redirection Endoluminal Device system is a dual-layer flow-diversion device. The purpose of this study was to evaluate the effectiveness and safety of the Flow-Redirection Endoluminal Device in a sidewall aneurysm model and in the abdominal aorta in rabbits. Single Flow-Redirection Endoluminal Devices were implanted in the right common carotid artery across sidewall, vein-pouch aneurysms and within the abdominal aorta in 22 New Zealand white rabbits and followed for 1 (n = 5), 3 (n = 5), 6 (n = 4), and 12 months (n = 8). Aneurysm occlusion was graded on a 3-point scale based on digital subtraction angiography (grade I, complete occlusion; grade II, near-complete occlusion; and grade III, incomplete occlusion). Toluidine blue and basic fuchsin staining was used for the evaluation of thrombus organization within the aneurysm and neck coverage with neointima. A scanning electron microscope was used for confirmation of the patency of branch vessels along with DSA. Grades I and II occlusion rates were noted in 19 (86%) and 3 (14%) aneurysms, respectively, which indicated a 100% rate of complete or near-complete occlusion. No parent artery and branch artery occlusion was shown on DSA. Histologic images indicated partial or complete intraluminal thrombus organization and neointima coverage across the aneurysm neck. A scanning electron microscope indicated that all the vessel branches along the length of the device remained patent. The Flow-Redirection Endoluminal Device in experimental aneurysms demonstrated high rates of progressive and complete aneurysm occlusion while preserving the patency of branch vessels.

Endovascular treatment of 346 middle cerebral artery aneurysms: results of a 16-year single-center experience.

The endovascular treatment of middle cerebral artery (MCA) aneurysms has been controversial because of the frequency of complex anatomy and the relative ease of surgical clipping in this location. To present a large single-center experience with the endovascular treatment of MCA aneurysms. The neurointerventional database at our institution was reviewed for all endovascular treatments of MCA aneurysms. Demographics, aneurysm characteristics, treatment modality, intraprocedural hemorrhagic and thromboembolic events, 30-day neurological events, and follow-up angiographic studies were recorded. From December 1996 to April 2013, 292 patients underwent endovascular treatment of 346 MCA aneurysms. Of these, 341 (98.6%) were successfully completed. Balloon neck remodeling was used in 230 procedures (66.5%). Ninety-five procedures (27.4%) were for ruptured aneurysms. The rate of intraprocedural hemorrhage was 2.6% (9 of 346). The overall rate of intraprocedural thromboembolic events was 13.6% (47 of 346), significantly more common in patients with acute subarachnoid hemorrhage (27.4%; P < .001). The 30-day major (modified Rankin Scale score > 2) neurological event rate was 2.9% (10 of 346), significantly more common in patients with subarachnoid hemorrhage (8.4%) compared with those without (0.8%; P < .001). The rate of complete or near-complete aneurysm occlusion at was 90.6% ≥ 6 months and 91.8% at ≥ 2 years, with an average of 24 months of follow-up available for 247 procedures. Endovascular treatment of MCA aneurysms can be safe and effective. However, it is associated with a high asymptomatic thromboembolic event rate that is more frequent in the setting of acute subarachnoid hemorrhage.

P-013 Predicting Mass Effect Exacerbation after Pipeline Embolization of Intracranial Aneurysms

IntroductionIn this study, we investigated the clinical and procedural predictors associated with interval growth manifested as new or worsened mass effect after Pipeline Embolization Device (PED) placement for treatment of...

Safety and long-term efficacy of endovascular treatment of small posterior communicating artery aneurysms by coiling with or without stent: A single center retrospective study

ObjectivesEndovascular stents have been widely used in intracranial aneurysm embolization. In this work, we compared the safety and long-term efficacy of stent-assisted coiling with those of conventional coiling for small posterior communicating artery aneurysms, aiming at a better understanding of the related safety and efficacy profiles. MethodsBetween January 2008 and December 2011, 114 small PcomA aneurysms (defined as 3mm≤maximum diameter<10mm in this study) in 108 patients were treated by endovascular treatment in our department. Patient demographics, aneurysm characteristics, angiographic results (initial and follow-up), and procedural complications were assessed. ResultsEmbolization was successfully performed in all the patients. Complications occurred in 7.4% of patients in both groups. There was no associated mortality. Based on initial post-procedural angiography, the rate of complete aneurysm occlusion, neck remnant and residual sac in the stented group were 37.9%, 24.1%, and 37.9%, while in the conventional group the figures were 42.9%, 48.2%, and 8.9%, respectively. The initial angiographic results were significantly better in the conventional group, compared with the stented group (P=0.038). The follow-up results showed that the rate of improvement in the stented group was significantly higher (53.3% vs. 14.0%; P<0.001) and the recurrence rate was significantly lower than that in the conventional group (4.4% vs. 3.02%; P=0.001). ConclusionCompared with conventional coiling, stent-assisted coiling of the small posterior communicating artery aneurysms does not increase the risk. Stents bear an advantage in reducing the recurrence rate, increasing progressive occlusion rate, and improving long-term prognosis in endovascular treatment of intracranial aneurysms.

The Art of Basilar Apex Aneurysm Surgery: Is It Sustainable in the Future?

There has been a massive shift in the balance toward endovascular therapy for basilar artery (BA) aneurysms in the modern era.We retrospectively reviewed clinical and radiologic data from patients with BA aneurysms who were treated in a single medical center during a 10-year period from August 2006 to May 2016.Thirty-five consecutive patients with 46 aneurysms during the 10-year period were included. The rate of complete aneurysm occlusion in 35 cases using a 1-stage operation was 58.8% (20/34). The graft patency rates of 13 bypass surgeries were 84.6% (11/13) within 1 week and 69.2% (9/13) at 3 months after surgery. The cut flow index for all bypass cases was 0.79. The overall survival was 94% at discharge (2 patients died). The 3-month outcome was favorable (modified Rankin Scale score 0–2) for 27 patients (77.1%) and poor (modified Rankin Scale score 3–5) for 5 patients (14.2%), and 3 patients died (8.6%). The survival for patients with BA apex aneurysms was higher than the survival observed for patients with BA trunk/vertebrobasilar junction aneurysms.Microsurgical treatments for BA aneurysms can be effective, with good patient outcomes in the early stage after operation. Patients with wide-necked, fusiform, or dolichoectatic aneurysms seem to exclude the aneurysm, preventing unnecessary retreatments with bypass techniques. The potential for a poor prognosis of patients with BA trunk/vertebrobasilar junction aneurysms was higher than that for patients with basilar apex aneurysms who presented with unfavorable subsequent events.

Pipeline for Uncoilable or Failed Aneurysms: Results from a Multicenter Clinical Trial

To evaluate the safety and effectiveness of the Pipeline Embolization Device (PED; ev3/Covidien, Irvine, Calif) in the treatment of complex intracranial aneurysms. The Pipeline for Uncoilable or Failed Aneurysms is a multicenter, prospective, interventional, single-arm trial of PED for the treatment of uncoilable or failed aneurysms of the internal carotid artery. Institutional review board approval of the HIPAA-compliant study protocol was obtained from each center. After providing informed consent, 108 patients with recently unruptured large and giant wide-necked aneurysms were enrolled in the study. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and absence of major stenosis at 180 days. The primary safety endpoint was occurrence of major ipsilateral stroke or neurologic death at 180 days. PED placement was technically successful in 107 of 108 patients (99.1%). Mean aneurysm size was 18.2 mm; 22 aneurysms (20.4%) were giant (>25 mm). Of the 106 aneurysms, 78 met the study's primary effectiveness endpoint (73.6%; 95% posterior probability interval: 64.4%-81.0%). Six of the 107 patients in the safety cohort experienced a major ipsilateral stroke or neurologic death (5.6%; 95% posterior probability interval: 2.6%-11.7%). PED offers a reasonably safe and effective treatment of large or giant intracranial internal carotid artery aneurysms, demonstrated by high rates of complete aneurysm occlusion and low rates of adverse neurologic events; even in aneurysms failing previous alternative treatments.

Stent-Assisted Coiling Versus Balloon Remodeling of Wide-Neck Aneurysms: Comparison of Angiographic Outcomes

Stent-assisted coiling and balloon-assisted coiling are 2 well-established techniques for treatment of wide-neck intracranial aneurysms. A direct comparative analysis of angiographic outcomes with the 2 techniques has not been available. We compare the angiographic outcomes of wide-neck aneurysms treated with stent-assisted coiling versus balloon-assisted coiling. A retrospective review was conducted on 101 consecutive patients treated at our institution, 69 with stent-assisted coiling and 32 with balloon-assisted coiling. Two multivariate logistic regression analyses were performed to determine predictors of aneurysm obliteration and predictors of progressive aneurysm thrombosis at follow-up. The 2 groups were comparable with respect to all baseline characteristics with the exception of a higher proportion of ruptured aneurysms in the balloon-assisted coiling group (65.6%) than in the stent-assisted coiling group (11.5%, P < .001). Procedural complications did not differ between the stent-assisted coiling group (6%) and the balloon-assisted coiling group (9%, P = .5). The rates of complete aneurysm occlusion (Raymond score 1) at the most recent follow-up were significantly higher for the stent-assisted coiling group (75.4%) compared with the balloon-assisted coiling group (50%, P = .01). Progressive occlusion of incompletely coiled aneurysms was noted in 76.6% of aneurysms in the stent-assisted coiling group versus 42.8% in the balloon-assisted coiling group (P = .02). Retreatment rates were significantly lower with stent-assisted coiling (4.3%) versus balloon-assisted coiling (15.6%, P = .05). In multivariate analysis, stented aneurysms independently predicted both complete aneurysm obliteration and progression of occlusion. Stent-assisted coiling may yield lower rates of retreatment and higher rates of aneurysm obliteration and progression of occlusion at follow-up than balloon-assisted coiling with a similar morbidity rate.

Biodegradable flow-diverting device for the treatment of intracranial aneurysm: short-term results of a rabbit experiment

One main complication of a flow-diverting device (FD) in treating intracranial aneurysm is stenosis of parent artery (PA) or occlusion of side branches. The use of a biodegradable device may satisfy the need for aneurysm occlusion and eliminate potential complications. Twenty elastase-induced aneurysm rabbit models were divided into three groups: in group 1 (n = 7), polyglycolic acid FDs (PGA-FDs) were implanted across the necks of aneurysms and the abdominal aortas (AA), covering the ostium of a lumbar artery; in group 2 (n = 7), the PGA-FDs were replaced by metal FDs; and in group 3 (n = 6), the PGA-FDs were only implanted across the necks of aneurysms. Animals in group 3 underwent angiography at 6weeks; those in groups 1 and 2 underwent angiography at 3months. The status of aneurysm embolization and patency of side branches were assessed. Complete aneurysm occlusion rates in groups 1 and 3 were 83.3 and 66.7%, respectively, compared with 0% in group 2. No side branch occlusions were noted. PA neointimal hyperplasia was minimal, and there were no significant differences between groups 1 and 2 (P = 0.233). The neointimal coverage ratio of the branch ostium in AA in group 1 was not significantly different from that in group 2 (P = 0.605). The neointima comprised predominantly smooth muscle cells and collagen fibers. The PGA-FD was an effective device for the treatment of aneurysms and was safe for side branches at the 3-month follow-up.

Intracranial Aneurysms: Midterm Outcome of Pipeline Embolization Device—A Prospective Study in 143 Patients with 178 Aneurysms

To evaluate the midterm clinical and angiographic outcomes after pipeline embolization device (PED) placement for treatment of intracranial aneurysms. This prospective nonrandomized multicenter study was approved by the review boards of all involved centers; informed consent was obtained. Patients (143 patients, 178 aneurysms) with unruptured saccular or fusiform aneurysms or recurrent aneurysms after previous treatment were included and observed angiographically for up to 18 months and clinically for up to 3 years. Study endpoints included complete aneurysm occlusion; neurologic complications within 30 days and up to 3 years; clinical outcome of cranial nerve palsy after PED placement; angiographic evidence of occlusion or stenosis of parent artery and that of occlusion of covered side branches at 6, 12, and 18 months; and clinical and computed tomographic evidence of perforator infarction. There were five (3.5%) cases of periprocedural death or major stroke (modified Rankin Scale [mRS] > 3) (95% confidence interval [CI]: 1.3%, 8.4%), including two posttreatment delayed ruptures, two intracerebral hemorrhages, and one thromboembolism. Five (3.5%) patients had minor neurologic complications within 30 days (mRS = 1) (95% CI: 1.3%, 8.4%), including transient ischemic attack (n = 2), small cerebral infarction (n = 2), and cranial nerve palsy (n = 1). Beyond 30 days, there was one fatal intracerebral hemorrhage and one transient ischemic attack. Ten of 13 patients (95% CI: 46%, 93.8%) completely recovered from symptoms of cranial nerve palsy within a median of 3.5 months. Angiographic results at 18 months revealed a complete aneurysm occlusion rate of 84% (49 of 58; 95% CI: 72.1%, 92.2%), with no cases of parent artery occlusion, parent artery stenosis (<50%) in three patients, and occlusion of a covered side branch in two cases (posterior communicating arteries). Perforator infarction did not occur. PED placement is a reasonably safe and effective treatment for intracranial aneurysms. The treatment is promising for aneurysms of unfavorable morphologic features, such as wide neck, large size, fusiform morphology, incorporation of side branches, and posttreatment recanalization, and should be considered a first choice for treating unruptured aneurysms and recurrent aneurysms after previous treatments. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120422/-/DC1.

Treatment results for complex middle cerebral artery aneurysms. A prospective single-center series

The objective was to assess the surgical results in complex middle cerebral artery (MCA) aneurysms. From 1999 to 2009 the data of 330 patients with ruptured and unruptured MCA aneurysms were included into a prospective database. Degree of aneurysm occlusion and clinical outcomes were analysed after 271 surgical and 59 endovascular treatments assigned in an interdisciplinary approach. Aneurysms of large size and/or broad base, calcifications, and incorporation of M1 or M2 segments into the aneurysm base were defined as complex. At least one of the criteria for complexity mentioned above was met in 97.8% of the MCA aneurysms that were treated surgically and in 76.3% that were treated endovascularly. In MCA aneurysms treated surgically, complete occlusion was achieved in 264 of the 271 (97.4%) aneurysms. Aneurysms with remnants after surgical treatment were significantly larger in size (17 ± 3mm vs 7 ± 5mm), and exhibited significantly more often parent vessel involvement (M1: 86% vs 27%; M2: 100% vs 67%) compared with the group of aneurysms that could be treated without remnant. Compared with our institutional data (52.5% complete occlusion rate) and data of the literature (up to 46.1% complete occlusion rate), the occlusion rates of endovascularly treated MCA aneurysms were significantly lower compared with MCA aneurysms treated surgically. Surgical treatment of ruptured and unruptured MCA aneurysms results in a significantly higher rate of complete aneurysm occlusion compared with endovascular treatment, despite a high rate of complex aneuryms in the surgically treated group.

Single-Center Experience of Surgical and Endovascular Treatment of Ruptured Intracranial Aneurysms

ISAT provided valuable data on patient outcome after endovascular coiling and surgical clipping of ruptured aneurysms. The purpose of this study was to retrospectively review the ≥1-year outcome (in terms of survival, independence, and rebleeding) of patients who were treated in a routine clinical setting. Records of patients presenting with an SAH from a ruptured aneurysm between 2000 and 2008 were reviewed. The 403 patients who met the inclusion criteria harbored 443 treated aneurysms; 173 were managed surgically and 230 by endovascular means. Mean clinical follow-up was 33.9 months (range, 12-106 months). The pretreatment clinical condition according to the HH was significantly better in the surgically treated patients (P = .018). Death occurred in 11.6% after surgery and in 17.4% after endovascular treatment (P = .104). Of the surviving patients in the surgical and endovascular groups, 80.3% and 87.2%, respectively, were able to live independently with grades 0-2 on the mRS (P = .084). Complete aneurysm occlusion was achieved significantly more often after surgical treatment (P < .001). Rebleeding occurred in 3.1% and 2.3% of the patients after surgical treatment and endovascular coiling, respectively. The occurrence of a residual aneurysm at the end of a coiling procedure was significantly related to the frequency of rebleeding (P = .007). The management of patients with intracranial aneurysms in a routine clinical setting shows good and comparable rates of mortality and independence. Coiling results in lower rates of complete aneurysm occlusion. Postcoiling angiography showing a residual aneurysm is a good predictor of the risk of rebleeding.