Stent-to-vessel diameter ratio is associated with in-stent stenosis after flow-diversion treatment of intracranial aneurysms.

BACKGROUND AND PURPOSE: Flow-diversion treatment for intracranial aneurysms has been associated with the development of in-stent stenosis (ISS) for unclear reasons. We assess whether the size of the stent relative to that of the vessel (the stent-to-vessel diameter ratio, or SVR) may be predictive of the development of ISS after treatment with flow diverters. METHODS: We retrospectively reviewed patients with unruptured intracranial aneurysms who underwent flow-diversion treatment using either the Pipeline or Tubridge embolization device from September 2018 to September 2022. The relationship between SVR and ISS was analyzed. Multiple logistic regression models were used to determine the significant predictors. RESULTS: A total of 458 patients with 481 aneurysms were included. In a mean angiographic follow-up of 10.73 ± 3.97 months, ISS was detected in 68 cases (14.1 %). After adjusting for candidate variables, a higher distal SVR (DSVR) was associated with an increased risk of ISS (adjusted odds ratio [aOR] = 3.420, 95 % confidence interval [CI] = 1.182 - 9.889, p = 0.023). We conducted a subgroup analysis of the two different flow diverters to assess the effects of their individual characteristics. Our results showed a significant association between the DSVR and the incidence of ISS in both the Pipeline (aOR = 4.033, 95 % CI = 1.156-14.072, p = 0.029) and Tubridge groups (aOR = 11.981, 95 % CI=1.005-142.774, p = 0.049). CONCLUSION: A higher DSVR was associated with an increased risk of ISS. This may help neurointerventionalists select an appropriate stent size when conducting flow-diversion treatment for intracranial aneurysms.

Early and midterm results of treatment of giant internal carotid artery paraclinoid aneurysms with trapping and flow diverters.

BACKGROUND: Flow diverter devices (FDD) carry risks of postoperative complications when treating aneurysms with wide necks, stenosis, and severe tortuosity of the parent vessel. In this study, we evaluated early and midterm results for the treatment of giant paraclinoid aneurysms managed by trapping and endovascular deployment of FDD. METHODS: Medical records were analyzed for patients with giant paraclinoid aneurysms treated between July 2008 and December 2017 at National Centre for Neurosurgery with either a flow diverter or by trapping the aneurysm with or without extracranial-intracranial (EC-IC) bypass surgery. We recorded age, sex, clinical presentation, treatment modality, morbidity, and mortality. Clinical outcomes were assessed using a modified Rankin scale (mRS). RESULTS: Among 29 consecutive patients, 13 were treated with FDD, and 16 patients were managed by trapping the aneurysm, where 7/16 cases had preliminary EC-IC bypass. Of 16 trapping patients, six were trapped endovascularly and ten were trapped surgically. During the follow-up period (mean 33 months, range 6-96), total exclusion of the aneurysm from the circulation was observed 100% of aneurysms in the trapping group and 84.6% in the FDD group (P = 0.192). Early postoperative morbidity was observed in three (23%) cases in the FDD group, and four (25%) in trapping group (P = 0.525). The FDD group had one (7.7%) fatal complication due to stent occlusion and severe ischemic stroke after three months postoperatively, despite appropriate antiplatelet therapy. There were no mortalities in the trapping group (P = 0.149). The rate of mRS 0-2 did not differ significantly across groups at discharge (81.3% vs. 69.2%; P = 0.667), and all patients had mRS 0-2 at follow-up (P = 1.000). CONCLUSIONS: FDD deployment for giant paraclinoid aneurysms results in comparable angiographic and clinical outcomes to aneurysm trapping. Despite implementation of modern endovascular treatment methods, aneurysm trapping remains a valuable treatment option in carefully selected patients with giant paraclinoid aneurysms.

Postprocedural, midterm, and long-term results of cerebral aneurysms treated with flow-diverter devices: 7-year experience at a single center.

OBJECTIVE Flow diversion has emerged as a viable treatment option for selected intracranial aneurysms and recently has been gaining traction. The aim of this study was to evaluate the safety and effectiveness of flow-diverter devices (FDDs) over a long-term follow-up period. METHODS The authors retrospectively reviewed all cerebral aneurysm cases that had been admitted to the Division of Neurosurgery of the Università degli Studi di Napoli between November 2008 and November 2015 and treated with an FDD. The records of 60 patients (48 females and 12 males) harboring 69 cerebral aneurysms were analyzed. The study end points were angiographic evidence of complete aneurysm occlusion, recanalization rate, occlusion of the parent artery, and clinical and radiological evidence of brain ischemia. The occlusion rate was evaluated according to the O'Kelly-Marotta (OKM) Scale for flow diversion, based on the degree of filling (A, total filling; B, subtotal filling; C, entry remnant; D, no filling). Postprocedural, midterm, and long-term results were strictly analyzed. RESULTS Complete occlusion (OKM D) was achieved in 63 (91%) of 69 aneurysms, partial occlusion (OKM C) in 4 (6%), occlusion of the parent artery in 2 (3%). Intraprocedural technical complications occurred in 3 patients (5%). Postprocedural complications occurred in 6 patients (10%), without neurological deficits. At the 12-month follow-up, 3 patients (5%) experienced asymptomatic cerebral infarction. No further complications were observed at later follow-up evaluations (> 24 months). There were no reports of any delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, ischemic complications, or procedure- or device-related deaths. CONCLUSIONS Endovascular treatment with an FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. In the present study, the authors observed effective and stable aneurysm occlusion, even at the long-term follow-up. Data in this study also suggest that ischemic complications can occur at a later stage, particularly at 12-18 months. On the other hand, no other ischemic or hemorrhagic complications occurred beyond 24 months.

Safety and efficacy of flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms: a single center experience.

BACKGROUND: Experience with the endovascular treatment of cerebral aneurysms by the Flow Re-Direction Endoluminal Device (FRED) is still limited. The aim of this study is to discuss the results and complications of this new flow diverter device (FDD). METHODS: Between November 2013 and April 2015, 20 patients (15 female and five male) harboring 24 cerebral aneurysms were treated with FRED FDD in a single center. RESULTS: Complete occlusion was obtained in 20/24 aneurysms (83 %) and partial occlusion in four (17 %). Intraprocedural technical complication occurred in one case (4 %) and post-procedural complications in three (12 %). None reported neurological deficits (mRS = 0). All FRED were patent at follow-up. No early or delayed aneurysm rupture, no subarachnoid (SAH) or intraparenchymal hemorrhage (IPH) no ischemic complications and no deaths occurred. CONCLUSIONS: Endovascular treatment with FRED FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. The FRED is substantially equivalent to the other known FDDs, which show similar functions and technical profiles.

Ongoing Geometric Remodeling of the Parent Artery After Flow-Diverter Stent Reconstruction in Cerebral Aneurysms: The Device Design Matters.

OBJECTIVE: Configuration changes of the parent artery (PA) after flow-diverter (FD) stent reconstruction, caused by the bending force of the device, may have an additional role in aneurysm occlusion as a result of the secondary alteration of intra-aneurysmal hemodynamics related to the geometry alteration of the vessel. To determine the degree of PA deformation and aneurysm occlusion rates after deployment of 2 different types of FD. METHODS: Patients treated with 2 different designs of cobalt-chromium braid (48 and 64 wire braid) structure FD were subject to analysis. Vascular angle changes at the level of the reconstructed segment immediately after FD deployment and at 1 year follow-up were measured and the potential relationship with aneurysmal occlusion rate was analyzed. RESULTS: Forty-two patients harboring 48 aneurysms were included in the present study. The aneurysms were divided into side wall (85.4%) and bifurcation types (14.6%). Twenty-six aneurysms were treated using the Pipeline FD (48 wire braid; 54.2%) and 22 using the Evolve FD (64 wire braid; 45.8%). Of the 48 aneurysms, 42 (87.5%) met the primary end point of complete occlusion at 12 months. The median postdeployment angle change was 7.04°± 4.59° for the Pipeline and 5.05°± 2.49° for the Evolve, whereas the median 12 months follow-up angle change was 15.49°± 10.99° and 10.01°± 8.83°, respectively. PA angle changes were significantly higher in the bifurcation group compared with the side wall group both during procedure and at 12 months follow-up. Angle change had a statistically nonsignificant association with complete aneurysm occlusion. CONCLUSIONS: PA deformation starts immediately after deployment and remodeling continues for 1 year after. Aneurysms located in the vessel bifurcation were more prone to PA straightening after FD deployment than were side wall aneurysms. Furthermore, Pipeline seemed to be more prone to inducing vascular deformation, compared with Evolve.

Indications for alternative endovascular techniques in carotid-cavernous fistulas: A 20-year single-center experience.

BACKGROUND: While coiling is considered the standard treatment for carotid-cavernous fistulas (CCFs), studies demonstrating excellent results using new materials, especially flow diverter (FD) stents and liquid embolisates, are becoming more frequent. The indications and effectiveness of these alternative endovascular techniques remain unclear. METHODS: A total of 22 direct and 20 indirect CCFs were included in the study. These were further subdivided based on the embolic material used: coils versus FD stents for direct and coils versus liquid embolisates for indirect CCFs. The subgroups were subjected to statistical analysis. RESULTS: An angiographic cure was achieved in 88% of all CCFs, 93% of patients' experienced clinical improvement or remained stable. Direct CCFs were treated with coiling (41%) or with both coils and FD stents (55%). One (4%) patient with a direct CCF was treated with FD stent alone. Statistical analysis comparing these subgroups revealed a significantly higher complete occlusion rate immediately after treatment in the coiling subgroup (67% vs. 23%, p = 0.0409). The occlusion rates at the last follow-up were similar (89% vs. 85%). Indirect CCFs were treated with coiling (35%) or liquid embolisates (65%). All three periprocedural ischemic complications were recorded within the liquid subgroup, resulting in a significantly higher clinical deterioration rate (p = 0.0333). CONCLUSION: FD stents in direct and liquid embolisates in indirect fistulas did not demonstrate better angiographic or clinical outcomes compared to convetional coiling. Liquid agents carried a higher risk of ischemic complications. Alternative embolization materials should be reserved for CCFs that cannot be treated with simple coiling.

Comparative Efficacy of Flow Diverter Devices in the Treatment of Carotid Sidewall Intracranial Aneurysms: a Retrospective, Multicenter Study.

BACKGROUND: The comparative efficacy and safety of first-generation flow diverters (FDs), Pipeline Embolization Device (PED) (Medtronic, Irvine, California), Silk (Balt Extrusion, Montmorency, France), Flow Re-direction Endoluminal Device (FRED) (Microvention, Tustin, California), and Surpass Streamline (Stryker Neurovascular, Fremont, California), is not directly established and largely inferred. PURPOSE: This study aimed to compare the efficacy of different FDs in treating sidewall ICA intracranial aneurysms. METHODS: We conducted a retrospective review of prospectively maintained databases from eighteen academic institutions from 2009-2016, comprising 444 patients treated with one of four devices for sidewall ICA aneurysms. Data on demographics, aneurysm characteristics, treatment outcomes, and complications were analyzed. Angiographic and clinical outcomes were assessed using various imaging modalities and modified Rankin Scale (mRS). Propensity score weighting was employed to balance confounding variables. The data analysis used Kaplan-Meier curves, logistic regression, and Cox proportional-hazards regression. RESULTS: While there were no significant differences in retreatment rates, functional outcomes (mRS 0-1), and thromboembolic complications between the four devices, the probability of achieving adequate occlusion at the last follow-up was highest in Surpass device (HR: 4.59; CI: 2.75-7.66, p < 0.001), followed by FRED (HR: 2.23; CI: 1.44-3.46, p < 0.001), PED (HR: 1.72; CI: 1.10-2.70, p = 0.018), and Silk (HR: 1.0 ref. standard). The only hemorrhagic complications were with Surpass (1%). CONCLUSION: All the first-generation devices achieved good clinical outcomes and retreatment rates in treating ICA sidewall aneurysms. Prospective studies are needed to explore the nuanced differences between these devices in the long term.

Single antiplatelet regimen in flow diverter treatment of cerebral aneurysms: The drug matters. A systematic review and meta-analysis.

BACKGROUND: Hemorrhagic and thromboembolic complications (TECs) are the main concerns in the endovascular treatment of intracranial aneurysms using flow diverter devices (FDs). The clinical demand for single antiplatelet therapy (SAPT) is increasing especially with the development of devices with lower thrombogenicity profile. However, the safety of SAPT is not well established. OBJECTIVE: To analyze the safety and efficacy of SAPT in terms of ischemic and hemorrhagic complications in patients undergoing FDs treatment for cerebral aneurysms. METHODS: A systematic literature search and meta-analysis were conducted in PubMed, Ovid MEDLINE, Ovid Embase, and Web of Science from January 2010 until October 2022. Twelve articles which reported SAPT and data on hemorrhagic, TECs, and mortality following FDs treatment were included. RESULTS: Overall, the 12 studies involved 237 patients with 295 aneurysms. Five investigated the safety and efficacy of SAPT in 202 unruptured aneurysms. Six studies focused on 57 ruptured aneurysms. One study included both ruptured and unruptured aneurysms. Among the 237 patients, prasugrel was most often used as SAPT in 168 cases (70.9%), followed by aspirin in 42 (17.7%) patients, and by ticagrelor in 27 (11.4%). Overall, the hemorrhagic complication rate was 0.1% (95% CI 0% to 1.8%). The TEC rate was 7.6% (95% CI 1.7% to 16.1%). In the subgroup analysis, the TEC rates of prasugrel monotherapy of 2.4% (95% CI 0% to 9.3%) and ticagrelor monotherapy of 4.2% (95% CI 0.1% to 21.1%) were lower than of aspirin monotherapy 20.2% (95% CI 5.9% to 38.6%). The overall mortality rate was 1.3% (95% CI 0% to 6.1%). CONCLUSION: According to the available data, SAPT regimen in patients undergoing FDs treatment for cerebral aneurysms has an acceptable safety profile, especially with the use of ADP-receptor antagonists.

Flow-diverter stents combined with flow-T stenting-assisted coiling for the treatment of a large basilar apex aneurysm: a case report with a 9-month follow-up.

Background: Endovascular or surgical treatment of wide-neck, large basilar apex aneurysms is challenging. We present a novel concept for the treatment of complex basilar apex aneurysms using flow-diverter devices combined with the flow-T stenting-assisted coiling technique. Assess the efficacy and safety profile of the technique in this complex aneurysm. Case description: A patient with multiple unruptured intracranial aneurysms underwent staged treatment. A large basilar apex aneurysm was treated with a flow-diverter stent combined with a flow-T stenting-assisted coiling technique in the first stage, and a giant supraclinoid aneurysm was treated with a flow-diverter stent applied in the second stage. Clinical presentations, technical details, intra- and perioperative complications, and clinical and angiographic outcomes were recorded, with a 9-month follow-up. Results: The patient achieved full neurologic recovery postoperatively. Cerebral angiography performed postoperatively showed revascularization, good laminar flow, and no in-stent or adjacent stenosis. Conclusion: Flow-diverter stents combined with flow-T stenting-assisted coiling for the treatment of giant basilar apex aneurysms is a feasible technique with efficacy demonstrated at a 9-month follow-up. Staged endovascular treatment of multiple intracranial aneurysms may be a safe and viable option.

Clinical impact of Sim & Size® simulation software in the treatment of patients with cerebral aneurysms with flow-diverter Pipeline stents.

OBJECTIVES: This study evaluated the clinical impact of the Sim&Size® simulation software on the endovascular treatment with flow-diverter stents of patients with unruptured saccular intracranial aneurysms. METHODS: This monocentric retrospective study evaluated a cohort of patients treated with flow-divert stents between June 1, 2014, and December 31, 2019, for cerebral aneurysms. Patients belonged to two groups, patients treated with and without the Sim&Size® simulation software. Univariate, bivariate, and multivariate analyses were used to evaluate the clinical impact of simulation software. RESULTS: Out of the 73 interventions involving 68 patients analyzed by the study, 76.7% were simulated using the Sim&Size® simulation software, and 23.3% were not. Patients treated with the simulation software had shorter stent lengths (16.00 mm vs. 20.00 mm p-value = 0.001) and surgical time (100.00 min vs. 118.00 min p-value = 0.496). Also, fewer of them required more than one stent (3.6% vs. 17.6% p-value = 0.079). Three patients belonging to the non-stimulated group presented hemorrhagic complications. CONCLUSIONS: Using the Sim&Size® simulation software for the endovascular treatment of intracranial aneurysms with pipeline flow-diverter stents reduces the stent length.

Failure of tandem flow diversion for intracranial aneurysms: Literature review and illustrative case.

Background: Flow diverters are becoming one of the main endovascular procedures used to treat aneurysms. Flow diverter devices (FDDs) have multiple types approved for endovascular procedure use. Although their indications are not well described, they are usually used for large or giant, wide-necked, and recurrent aneurysms. Multiple FDDs can be deployed to treat giant aneurysms to ensure and accelerate aneurysm occlusion and mitigate complications. We report a case of endovascular treatment of an intracranial aneurysm using three silk FDDs complicated by a delayed migration of the stents along the parent artery, along with a literature review of the related cases. Methods: We conducted a PubMed Medline database search by the following combined formula of subjects headings: ((((((intracranial aneurysm[MeSH Terms]) AND (endovascular procedure[MeSH Terms])) OR (endovascular technique[MeSH Terms])) AND (endovascular[Title/Abstract]) AND (Flow diverter[Title/ Abstract])) OR (flow diversion[Title/Abstract])) OR (Pipeline[Title/Abstract])) AND (Multiple[Title/Abstract]). Results: The result was eight cases of endovascular treatment of intracranial aneurysms with multiple FDD. The male-to-female ratio in these cases was 5:3, and there is a wide age range from 22 months to 69 years old. The cases differed in the type and number of FDDs used, yet, they all had similar results with aneurysm occlusion and recovery of the patient with no observed complications. Conclusion: Tandem flow diverter deployment has technical challenges and complications such as complete obstruction can occur. Planning and learning from experience with those new technologies are the typical way to overcome such complications in the future.

Treatment of carotid cavernous sinus fistulas with flow diverters. A case report and systematic review.

INTRODUCTION: Carotid cavernous fistulas (CCFs) are rare, usually follow head trauma or aneurysmal rupture. Recent treatment options include endovascular techniques such as flow diversion devices (FDDs). OBJECTIVE: To present our case treated with FDD application with transarterial cavernous-sinus coiling and present a systematic review on the use and effectiveness of FDDs in CCF treatment. MATERIALS AND METHODS: We present our case of CCF treatment with FDD. A search was also conducted in PubMed, EMBASE and Cochrane until November 2020. Reference lists were also cross-checked. RESULTS: Including our case, thirty-eight patients were identified with a CCF that was treated with FDDs in sixteen studies. Twenty-two patients were females, nine were males and the rest unidentified. The mean age was 52,6 years (range 17-86, SD± 19.28). Thirty-six patients suffered from direct and two from indirect CCFs. Single FDD was used in four cases, single FDD with embolic materials in eleven cases, multiple overlapping FDDs were used in six cases and multiple overlapping FDDs with embolic materials were used in seventeen cases. Thirty-five patients (92,1%) had clinical improvement, immediate angiographic occlusion was seen in 44,7% of the cases, while long-term occlusion rate was 100% but with variable follow-up periods. One patient (2,6%) presented with a neurological deficit related to FDD deployment. CONCLUSION: Targeted treatment of CCFs with single or overlapping FDDs with or without adjunct embolic agents offers a high success rate, both clinically and long-term angiographically compared to other endovascular methods alone. However, further research with multi-center prospective trials is warranted.

A multicenter retrospective controlled study of the Pipeline™ and Tubridge™ Flow Diverter devices for intracranial wide-necked aneurysms.

Purpose: To compare the safety and efficacy of PipelineTM and TubridgeTM Flow Diverter devices (FDs) in the treatment of intracranial wide-necked aneurysms. Methods: We retrospectively analyzed the clinical data of 92 patients with intracranial wide-necked aneurysms who were treated with those two flow-diverter devices (FDs) at four participating centers between July 2012 and December 2020. Results: This study included 92 patients who underwent endovascular therapy using either Pipeline™ (n = 39) or TubridgeTM (n = 53) for treating intracranial wide-necked aneurysms. The periprocedural complication developed in 2.56% (1/39) patients of Pipeline group and 3.77% (2/53) patients of the TubridgeTM group. During perioperative period, one patient in Pipeline™ group showed subarachnoid hemorrhage (2.56%, 1/39) and two ischemic complications in the Tubridge™ group (3.77%, 2/53). Follow-up assessments were conducted on 31 patients (79.49%) in the Pipeline™ group (the mean follow-up period was 9.7 ± 3.3 months). The rate of complete aneurysm occlusion at the final angiographic follow-up was 77.42%. Patients with a modified Rankin scale (mRS) score of 0.44 ± 0.31. Follow-up assessments were conducted on 42 patients (79.25%) in the TubridgeTM group (the mean follow-up period was 9.1 ± 4.4 months). The rate of complete aneurysm occlusion at the final angiographic follow-up was 85.71%. Patients with mRS score of 0.52 ± 0.28. Three patients showed parent artery stenosis, and one showed parent artery occlusion. Conclusion: Both the PipelineTM and TubridgeTM are safe and effective for the treatment of intracranial wide-necked aneurysms, with no significant difference in the rate of complete aneurysm occlusion and perioperative complications between the two FDs.

Anterior Circulation Fusiform Aneurysms Have a Lower Occlusion Rate After Pipeline Embolization Device Treatment Than Posterior Circulation Fusiform Aneurysms: A Multicenter Cohort Study.

Objective: Intracranial fusiform aneurysms are uncommon and can occur in vessels of the anterior circulation (AC) or posterior circulation (PC). While flow diversion is one treatment option, research into Pipeline Embolization Device (PED) treatment is lacking. This study explored the efficacy and safety of PED treatment for intracranial fusiform aneurysms, and compared therapeutic effects between AC and PC aneurysms. Methods: In the post-market multi-center cohort study of embolization of intracranial aneurysms with PED in China (PLUS) registry study, we retrospectively analyzed 71 fusiform aneurysms in 67 patients among 1,171 patients treated with a PED from November 2014 to October 2019. The general characteristics, perioperative status, aneurysm occlusion rate at the last follow-up angiography, and changes in modified Rankin Scale scores were analyzed. Aneurysms were divided into AC and PC groups, and univariate and multivariate analyses were conducted. Results: The study included 26 AC (25 patients) and 45 PC (42 patients) aneurysms. A total of 75 PEDs were used, an average of 1.1 PEDs were used, and the median follow-up was 6.7 months. Fifty aneurysms (71.4%) were occluded and twenty (28.5%) were incompletely occluded. There were significantly more occluded aneurysms in the PC group than in the AC group (12 vs. 38; P = 0.001). Risk factors for incomplete occlusion were AC aneurysms (P = 0.001) and a perforating artery originating from the aneurysm (P = 0.006). The mean modified Rankin Scale score was significantly lower at the last follow up than preoperatively (0.58 vs. 0.21; P = 0.0001). Conclusion: Non-overlapping PED is a safe and effective treatment for both AC and PC fusiform aneurysms. The occlusion rate of AC fusiform aneurysms is lower than that of PC.

Flow diverter embolization device for endovascular treatment of ruptured blister and wide necked very small aneurysms.

PURPOSE: Ruptured blood blisters (BBA) and very small, wide necked aneurysms (VSA) remain challenging lesions to treat due to their small size, wide necks, and thin, fragile walls. In the present study, we reviewed our experience with these aneurysms treated by flow diversion. METHODS: A total of 18 patients with hemorrhage due to a ruptured BBAs and VSAs, treated with flow diversion between July 2014 and March 2016 were included in this study. We analyzed clinical and radiographic outcomes. RESULTS: A total of 12 (66.7%) VSAs and 6 (33.3%) BBAs were treated with flow diversion. Fifteen (83.3%) and three (16.7%) aneurysms were located on the internal carotid artery and the basilar artery, respectively. On admission, a GCS score of 15 and WFNS grade 1 were found in 14 (77.7%) patients, 3 patients had an admission GCS of 13 and WFNS grade 2, one had an admission GCS of 8 and WFNS of 4. Fisher CT grades 2, 3, and 4 were observed in 11 (61.1%), 1 (5.6%), and 6 (33.3%) patients, respectively. Flow diversion was performed on average 5.6 days after onset of hemorrhage. 6 months post-intervention angiography showed complete obliteration of the aneurysms in all patients. CONCLUSION: Our findings indicate that flow diversion in the acute and subacute phase of hemorrhage is a reliable treatment for reducing complications in patients with BBAs and VSAs. In patients with poor clinical presentation it might be reasonable to delay treatment until the first signs of recovery become apparent.

Meta-Analysis of the Efficiency and Prognosis of Intracranial Aneurysm Treated with Flow Diverter Devices.

Flow diverter devices (FDDs) are increasingly used in the treatment of intracranial aneurysm. The safety and feasibility of FDD were assessed in published literature. In accordance with strict inclusion criteria, Medline, Embase, Cochrane, China National Knowledge Infrastructure, and Web of Science databases were searched for literature that covers a period until February 2015. The baseline characteristics of patients, aneurysms, aneurysm occlusion, morbidity, and mortality were also collected. A meta-analysis was conducted using STATA 12.0, and a chi-squared test was performed to evaluate whether statistically significant differences existed between complications and mortality of aneurysm patients. Finally, a total of 48 studies were selected, including 2508 patients with 2826 aneurysm cases. The mean follow-up interval is 6.3 months, and the aneurysm occlusion rate is 77.9 % (95 % CI 73.8-81.9, I (2) = 43.4 %). The total morbidity and mortality rates are 9.8 and 3.8 %, respectively. The rates of spontaneous rupture and intraparenchymal hemorrhage are 2.0 and 2.5 %, respectively. The rate of ischemic stroke is 5.5 %. The morbidity and mortality rates of giant aneurysms are significantly higher than those of small and large aneurysms (χ (2) = 56.96, p < 0.05; χ (2) = 14.88, p < 0.05). The morbidity rates of posterior aneurysms are significantly higher than those of anterior (χ (2) = 11.29, p < 0.05) and unruptured aneurysms (χ (2) = 10.36, p < 0.05), respectively. The publication bias of aneurysm occlusion was detected by Begg's rank, and the corrected result is less than 0.05. Our meta-analysis suggests that the treatment of intracranial aneurysm with FDD is feasible and effective with a high occlusion rate, acceptable morbidity, and mortality. However, the morbidity or mortality of giant aneurysms is still high.

Endovascular treatment of cerebral aneurysms using flow-diverter devices: A systematic review.

BACKGROUND: Flow-diverter devices (FDDs) are new-generation stents placed in the parent artery at the level of the aneurysm neck to disrupt the intra-aneurysmal flow thus favoring intra-aneurysmal thrombosis. OBJECTIVE: The objective of this review article is to define the indication and results of the treatment of intracranial aneurysms by FDD, reviewing 18 studies of endovascular treatment by FDDs for a total of 1704 aneurysms in 1483 patients. METHODS: The medical literature on FDDs for intracranial aneurysms was reviewed from 2009 to December 2014. The keywords used were: "intracranial aneurysms," "brain aneurysms," "flow diverter," "pipeline embolization device," "silk flow diverter," "surpass flow diverter" and "FRED flow diverter." RESULTS: The use of these stents is advisable mainly for unruptured aneurysms, particularly those located at the internal carotid artery or vertebral and basilar arteries, for fusiform and dissecting aneurysms and for saccular aneurysms with large necks and low dome-to-neck ratio. The rate of aneurysm occlusion progressively increases during follow-up (81.5% overall rate in this review). The non-negligible rate of ischemic (mean 4.1%) and hemorrhagic (mean 2.9%) complications, the neurological morbidity (mean 3.5%) and the reported mortality (mean 3.4%) are the main limits of this technique. CONCLUSION: Treatment with FDDs is a feasible and effective technique for unruptured aneurysms with complex anatomy (fusiform, dissecting, large neck, bifurcation with side branches) where coiling and clipping are difficult or impossible. Patient selection is very important to avoid complications and reduce the risk of morbidity and mortality. Further studies with longer follow-up are necessary to define the rate of complete occlusion.

Treatment of intracranial aneurysms by flow diverter devices: long-term results from a single center.

OBJECTIVES: Flow-Diverter Devices (FDD) are a new generation stents designed for the treatment of the intracranial aneurysms. This article reports the long-term results (2-4 years) of this treatment from a single-center. METHODS: From November 2008 to January 2012, 35 patients (29 females and 6 males; mean age 53.9 y) with 39 intracranial aneurysms were treated by FDD. Five patients (14.3%) had ruptured aneurysms and 30 (85.7%) had no previous hemorrhage. The procedures were performed in 5 patients (14.3%) with SILK and in 30 (85.7%) with PED. In 3 patients FDDs were used as a second treatment after failure of previous coiling (2 cases) or stenting (one case). The 39 aneurysms were in supraclinoid ICA in 26 (66.7%), cavernous ICA in 2 (5.1%), PCoA in 4 (10.2%), MCA in 5 (12.9%), SCA in 1 (2.6%) and PICA in 1 (2.6%). The aneurysms were small (<10mm) in 32 cases (82%), large (11-25mm) in 6 (15.3%) and giant in 1 (2.6%). The occlusion rate according to the aneurysm location, size and neck and the complications were evaluated. RESULTS: Peri-procedural complications included transient dysarthria (2 patients), vasospasm with acute intra-stent aggregation (one), microwire rupture (one) and failure of the stent opening (one). The follow-up was made between 24 and 62 months (mean 41 months); clinical examination and CTA were performed at 1, 3, 6 and 12 months after the procedure. The complete occlusion was confirmed by CTA and DSA. MRI with angiographic-studies was taken every year. Complete occlusion was obtained in 35 aneurysms (92.1%) and subtotal in 3 (7.9%). Complete occlusion occurred at 3 months in 24 cases (68.6%), within 3 and 6 months in 9 (25.7%). The rate and time of complete occlusion were not correlated with the aneurysm size. MCA aneurysms mainly showed partial occlusion (2/3 cases). Besides, large-neck aneurysms and those with a vessel arising from the sac mainly showed late (>6 months) or partial occlusion. CONCLUSION: FDD are a safe and efficacious treatment of intracranial aneurysms, resulting in high occlusion rate and low incidence of complications. It should be the treatment of choice for the large-neck aneurysm of the ICA.