Endovascular Coiling versus Surgical Clipping for Poor-Grade Ruptured Intracranial Aneurysms: Postoperative Complications and Clinical Outcome in a Multicenter Poor-Grade Aneurysm Study

BACKGROUND AND PURPOSE:Endovascular coiling is an alternative to surgical clipping for ruptured intracranial aneurysms. However, no large multicenter prospective study has compared coiling and clipping in patients with poor-grade ruptured aneurysms. We aimed to determine differences in postoperative complications and clinical outcome between the 2 treatments in this group of patients.MATERIALS AND METHODS:A Multicenter Poor-Grade Aneurysm Study was a prospective, multicenter, observational registry of consecutive patients who presented with poor-grade ruptured aneurysms. Three hundred sixty-six patients were enrolled from October 2010 to March 2012. “Poor-grade aneurysm” was defined as a World Federation of Neurosurgical Societies grade of IV or V at the time of aneurysm treatment. Two hundred sixty-two patients received aneurysm treatment within 21 days and were included. Clinical outcomes were assessed at discharge and at 6 and 12 months by the modified Rankin Scale.RESULTS:One hundred thirty-three (50.8%) patients underwent endovascular coiling. Unadjusted analysis showed that the outcome rate (mRS 0–1 or mRS 0–2) at 6 and 12 months in patients undergoing coiling was higher than that in patients undergoing clipping. In adjusted analyses, there was no statistically significant difference in outcomes at 6 and 12 months between the 2 groups. The risk of radiologic hydrocephalus was higher in patients treated with coiling than that in those treated with clipping (adjusted OR, 3.36; 95% CI, 1.13–10.01; P = .030).CONCLUSIONS:The long-term outcome in selected patients was similar between endovascular coiling and clipping for poor-grade ruptured aneurysms. The risk of radiologic hydrocephalus was higher after endovascular treatment of poor-grade aneurysms.

Intracranial aneurysm rupture leading to aneurysmal subarachnoid hemorrhage (aSAH) is a devastating condition. Poor-grade ruptured aneurysms account for approximately 30% of all cases of aSAH.^1,2 Traditionally, patients with poor-grade aneurysms have been managed medically. In the past 2 decades, aggressive treatment has been proposed to improve outcomes in selected patients.^1,3,4 Despite recent advances in the treatment of aSAH, patients with poor-grade aneurysms have high rates of long-term morbidity and mortality.^1,3–6The International Subarachnoid Aneurysm Trial (ISAT) has demonstrated that for ruptured aneurysms suitable for endovascular embolization and clipping, patients treated with coiling had better outcomes than those treated with clipping.^7,8 However, only a few patients (4.4%) in ISAT had poor-grade aneurysms. The results may not directly apply to poor-grade patients. Currently, case series have shown that endovascular coiling is a viable alternative to clipping for poor-grade aneurysms.^5,9,10 However, to date, no randomized, controlled study has been performed to evaluate the efficacy of coiling versus clipping for poor-grade ruptured aneurysms, to our knowledge. There has been no large multicenter prospective study regarding the effects of different treatments on postoperative complications and clinical outcome in these patients.A Multicenter Poor-Grade Aneurysm Study (AMPAS) was a prospective, multicenter, observational registry of consecutive patients who presented with poor-grade ruptured aneurysm.¹¹ The primary purpose of this report was to determine differences in postoperative complications and clinical outcome between patients treated with coiling and those treated with clipping in the AMPAS after adjustment for differences in baseline confounders.     

Complications in Stent-Assisted Endovascular Therapy of Ruptured Intracranial Aneurysms and Relevance to Antiplatelet Administration: A Systematic Review

BACKGROUND AND PURPOSE:Despite the increasing use of stent-assisted coiling for ruptured intracranial aneurysms, there is little consensus regarding the appropriate antiplatelet administration for this. The objectives of this systematic review were to provide an overview of complications and their association with the method of antiplatelet administration in stent-assisted coiling for ruptured intracranial aneurysms.MATERIALS AND METHODS:A comprehensive search of the literature in the data bases was conducted to identify studies reporting complications of stent-assisted coiling for ruptured intracranial aneurysms. The pooled event rate of preprocedural thromboembolisms, hemorrhages, and mortality was estimated from the selected studies. Subgroup analyses were performed by the method of antiplatelet administration (pre-, postprocedural, and modified). Meta-analysis was conducted to compare periprocedural complications and mortality between ruptured intracranial aneurysms and unruptured intracranial aneurysms.RESULTS:Of the 8476 studies identified, 33 with 1090 patients were included. The event rates of thromboembolism and intra- and postprocedural hemorrhage were 11.2% (95% CI, 9.2%–13.6%), 5.4% (95% CI, 4.1%–7.2%), and 3.6% (95% CI, 2.6%–5.1%), respectively. Subgroup analyses of thromboembolism showed a statistically significant difference between groups (P < .05). In the preprocedural and modified antiplatelet groups, the risk for thromboembolism in stent-assisted coiling for ruptured intracranial aneurysm was not significantly different from that for unruptured intracranial aneurysm, though this risk of the postprocedural antiplatelet group was significantly higher in ruptured intracranial aneurysms than in unruptured intracranial aneurysms.CONCLUSIONS:On the basis of current evidence, complications of stent-assisted coiling for ruptured intracranial aneurysm may be affected by the method of antiplatelet administration.

Aneurysmal neck remodeling with stents has recently emerged as an effective treatment option. This method is beneficial for treating aneurysms with wide necks or for situations in which coils unexpectedly herniate into the parent vessel, requiring rescue with a device that can reconstrain the coil within the lesion.¹ Currently, various stents specialized for aneurysmal neck remodeling are used during endovascular treatment of intracranial aneurysms. However, physicians are often reluctant to apply stents to acutely ruptured aneurysms due to the necessity of antiplatelet medications. During implantation of stents within an intracranial artery, antiplatelet agents should be administrated and maintained postoperatively to prevent in-stent thrombosis and subsequent ischemic events.² In the setting of acutely ruptured aneurysms, antiplatelet medications may lead to complications such as intraprocedural rebleeding, the need for a ventriculostomy, co-occurrence of an intraparenchymal hematoma, and a high likelihood of future invasive procedures.^3–7Despite the chance of complications, administration of antiplatelet agents is an important element of management when using an intracranial stent, regardless of the presence of an acute aneurysm rupture. The type and/or method of antiplatelet agent might affect the periprocedural complication rate of endovascular aneurysm treatment.^8,9 Despite many previous studies of stent-assisted aneurysm management, no published recommendations or large randomized clinical trials provide a consensus as to the appropriate method of antiplatelet medication in stent-assisted endovascular treatment for ruptured intracranial aneurysms (RIAs). The medication method usually varied depending on the institution or the rationales of clinicians in most published case series. Some review articles suggested a higher risk of complications in endovascular therapy for acutely ruptured aneurysms.^3,10,11 However, these reviews did not analyze independent factors affecting the risk of complications in stent-assisted coiling for RIA, including the application of antiplatelet agents.The purposes of this systematic review were to calculate the accumulated complication risk during stent-assisted coiling for RIA and to assess whether the risk of complications would be affected by the method of antiplatelet administration. This information will guide selection of safer antiplatelet administration for stent-assisted coiling of RIA.     

Safety and Efficacy of Intravenous Tirofiban as Antiplatelet Premedication for Stent-Assisted Coiling in Acutely Ruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE:Stent-assisted coiling of intracranial aneurysms requires antiplatelet therapy, typically aspirin and clopidogrel to prevent thromboembolic complications. There is a substantial concern that tirofiban may increase the risk of hemorrhage when used as an antiplatelet premedication in ruptured intracranial aneurysms. Our aim was to evaluate the safety and efficacy of intravenous tirofiban administration, instead of oral dual antiplatelet agents, as an antiplatelet premedication for stent-assisted coiling in patients with acutely ruptured intracranial aneurysms.MATERIALS AND METHODS:We conducted a retrospective review of a data base containing a consecutive series of patients who underwent stent-assisted coiling for acutely ruptured intracranial aneurysms between March 2010 and January 2015. Intravenous tirofiban was administered to all patients before stent-assisted coiling, instead of premedication with loading doses of aspirin or clopidogrel.RESULTS:Forty patients with 41 aneurysms received intravenous tirofiban and underwent stent-assisted coiling. None of the patients had a newly developed intracerebral hemorrhage, subarachnoid hemorrhage, or intraventricular hemorrhage. Intraprocedural aneurysmal rupture occurred in 2 patients (5%). Cerebral infarction developed in 2 patients (5%). Ventriculostomy-related hemorrhage was seen in 2 of 10 patients in whom ventriculostomy was performed before or after coiling. Thirty-four (85%) patients had a good outcome (Glasgow Outcome Score of 4 or 5) at the time of discharge, but 1 patient died of cardiac arrest. None of the patients developed thrombocytopenia, retroperitoneal, gastrointestinal, or genitourinary bleeding related to tirofiban administration.CONCLUSIONS:In our study, tirofiban showed a low risk of symptomatic hemorrhagic or thromboembolic complications. Tirofiban may offer a safe and effective alternative as an antiplatelet premedication during stent-assisted coiling of acutely ruptured intracranial aneurysms.

Results from the International Subarachnoid Aneurysm Trial showed that the endovascular management of intracranial aneurysm is a safe, effective, and sometimes preferable treatment option.¹ However, endovascular treatment of ruptured wide-neck aneurysms is still a challenge to neurointerventionalists because of the controversy surrounding the use of stent placement as an adjuvant therapy for the coiling of acutely ruptured aneurysms, due to the need for antiplatelet medications. Stent-assisted procedures are particularly prone to thromboembolic complications, with a reported rate of thromboembolic events of 7%–15% during stent-assisted coiling.^2–4 Therefore, there is a need for preoperative antiplatelet therapy with optimal anticoagulation during the procedures, even with subarachnoid hemorrhage. However, there is no consensus about when and how patients should be loaded with antiplatelet medication before the procedure.Glycoprotein IIb/IIIa antagonists have attracted attention for the prevention or treatment of thromboembolism during coiling of intracranial aneurysms,^5–7 but the increased risk of intracranial hemorrhage following glycoprotein IIb/IIIa inhibition remains a substantial concern. Moreover, the safety and efficacy data regarding the use of tirofiban in endovascular aneurysm treatment are lacking.The objective of our study was to evaluate the safety and efficacy of intravenous tirofiban, instead of clopidogrel and aspirin, as an antiplatelet premedication for stent-assisted coiling in patients with acutely ruptured intracranial aneurysms.     

WEB Treatment of Ruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE:The Woven EndoBridge (WEB) device was recently introduced for intrasaccular treatment of wide-neck aneurysms without the need for adjunctive support. We present our first experience in using the WEB for small ruptured aneurysms.MATERIALS AND METHODS:During 11 months, 32 of 71 (45%) endovascularly treated acutely ruptured aneurysms were treated with the WEB. The patients were 12 men and 20 women, with a mean age of 61 years (range, 34–84 years). The mean aneurysm size was 4.9 mm, and 14 were ≤4 mm. Of 32 aneurysms, 24 (75%) had a wide neck.RESULTS:All 32 aneurysms were adequately occluded after WEB placement. There were no procedural ruptures and no complications related to the WEB device. No adjunctive stents or balloons were needed. In 3 patients, thromboembolic complications occurred. One patient developed an infarction, and 2 patients were asymptomatic. The procedural complication rate was 3%. Seven patients admitted in poor clinical grade conditions died during hospital admission due to the sequelae of SAH. In 18 patients with angiographic follow-up at 3 months, 16 aneurysms remained adequately occluded. Two aneurysms showed slight compression of the WEB without reopening. Clinical follow-up in the 25 patients who survived the hospital admission period revealed mRS 1–2 in 24 and mRS 4 in 1. There were no rebleeds from the ruptured aneurysms during follow-up.CONCLUSIONS:WEB treatment of small ruptured aneurysms was safe and effective without the need for anticoagulation, adjunctive stents, or balloons. Our preliminary experience indicates that the WEB may be a valuable alternative to coils in the treatment of acutely ruptured aneurysms.

Endovascular treatment with coils of wide-neck intracranial aneurysms remains a technical challenge. To prevent extrusion of coils from the aneurysmal sac, a temporary protection balloon or a stent can be used. However, this makes the procedure more complicated with a higher chance of complications.^1,2 With the use of stents, periprocedural dual-antiplatelet therapy is required and has to be prolonged for 3–6 months. With this anticoagulation, stent-assisted coiling in ruptured aneurysms has a higher inherent risk for early rebleed or hemorrhage in the postoperative period.³Recently, an intrasaccular flow disruptor, Woven EndoBridge (WEB; Sequent Medical, Aliso Viejo, California), has been developed. The primary use of the WEB is the treatment of bifurcation or wide-neck aneurysms without the need of adjunctive devices. There is a growing body of literature on the use of the WEB device with excellent safety and efficacy profiles. Most of the published series comprised wide-necked, unruptured aneurysms.^4–16 When the WEB became available in our hospital, our initial results in unruptured aneurysms were encouraging, and we decided to expand the indications to both ruptured and unruptured aneurysms suitable for accommodating a WEB device, regardless of neck size. Our intention was to avoid using stents or balloons in ruptured aneurysms. In this article, we present our first results of the use of the WEB device in small ruptured aneurysms.     

支架结合弹簧圈在栓塞颅内复杂动脉瘤中的应用

目的 探讨支架结合弹簧圈在栓塞颅内复杂动脉瘤中的应用价值以及急性期使用支架的安全性.资料与方法 29例患者,32个动脉瘤.采用Neuroform支架,弹簧圈主要采用Matrix、Orbit圈,分析栓塞效果.急性期支架辅助栓塞宽颈动脉瘤20例.择期栓塞患者术前3天予以强抗血小板聚集药物,所有患者术后予强抗血小板聚集药物及5天抗凝治疗.术后复查21例.结果 所有病例栓塞操作均顺利完成,无手术并发症;除1例巨大动脉瘤为次全栓塞外,其他均致密栓塞.其中1枚支架覆盖2个动脉瘤并栓塞3例,支架辅助栓塞巨大宽颈动脉瘤3例,支架置入行二期动脉瘤颈残留弹簧圈再栓塞2例,动脉瘤常规弹簧圈栓塞后3年复发再以支架辅助栓塞1例.急症支架辅助微弹簧圈栓塞动脉瘤未发现支架内血栓形成或狭窄堵塞.复查21例中,除1例次全栓塞的巨大动脉瘤出现动脉瘤腔部分显影外,其余20例均未见动脉瘤显影.结论 支架结合不同型号弹簧圈栓塞有助于提高颅内复杂动脉瘤的治疗成功率;急性期可以使用支架,但在未行抗血小板聚集药物准备的前提下,其安全性有待进一步研究.     

颅内宽颈动脉瘤的介入治疗

介入治疗已成为颅内动脉瘤治疗的重要手段。电解可脱卸弹簧圈（GDC）栓塞颅内动脉瘤具有微创、安全、效果可靠的优点。但宽颈动脉瘤的致密栓塞率低，复发率高，如何提高颅内动脉瘤的致密栓塞是该技术的要点和难点。动脉瘤微导管的双弯塑型、横向成篮、篮外填塞、分部填塞及瘤颈重塑型技术可明显提高动脉瘤的致密栓塞率。常见的并发症有术中出血、血栓栓塞、血管痉挛等，迅速继续填塞动脉瘤是处理术中出血最有效的措施；实施腰蛛网膜下腔持续引流，释放血性脑脊液，辅以抗凝及“3H”治疗是防治脑血管痉挛和血栓栓塞的关键。对于特别宽颈及梭形动脉瘤，无法单纯采用GDC治疗，血管内支架结合GDC是治疗颅内梭形及宽颈动脉瘤的有效方法。正确的支架选择，防止支架移位，是手术成功的关键，但确切疗效需进一步长期随访。     

Hemorrhagic Complications after Endovascular Treatment of Cerebral Arteriovenous Malformations

BACKGROUND AND PURPOSE:Intracranial hemorrhage is the most severe complication of brain arteriovenous malformation treatment. We report our rate of hemorrhagic complications after endovascular treatment and analyze the clinical significance and potential mechanisms, with emphasis on cases of delayed hemorrhage after uneventful embolization.MATERIALS AND METHODS:During a 10-year period, 846 embolization procedures were performed in 408 patients with brain AVMs. Any cases of hemorrhagic complications were identified and divided into those related or unrelated to a periprocedural arterial tear (during catheter navigation or catheter retrieval). We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM, number of embolized pedicles, microcatheter used, type and volume of liquid embolic agent injected, and the presence of a premature venous occlusion. Univariate and multivariate multiple regression analyses were performed to identify risk factors for hemorrhagic complications.RESULTS:A hemorrhagic complication occurred in 92 (11%) procedures. Forty-four (48%) complications were related to a periprocedural arterial perforation, and 48 (52%) were not. Hemorrhagic complications unrelated to an arterial perforation were located more commonly in the cerebral parenchyma, caused more neurologic deficits, and were associated with worse prognosis than those in the arterial perforation group. Only premature venous occlusion was identified as an independent predictor of hemorrhagic complication in the nonperforation group. Premature venous occlusion was significantly related to the ratio of Onyx volume to nidus diameter.CONCLUSIONS:Higher injected volume of embolic agent and deposition on the venous outflow before complete occlusion of the AVM may account for severe hemorrhagic complications.

Treatment of cerebral arteriovenous malformation is challenging and requires a multidisciplinary approach involving surgery with AVM removal, endovascular treatment (EVT) with embolization, or radiosurgery. Each technique can be combined and has its own advantages and complications. A conservative approach is an important aspect of the management of AVMs. EVT can be used for presurgical or preradiosurgical treatment of AVMs or as a stand-alone procedure for curative purposes. Onyx (Covidien, Irvine, California) is currently the most commonly used embolic agent; in some instances, cyanoacrylate glue can be used. The most serious complication of AVM embolization is hemorrhage, reported in 4%–15% of patients treated by EVT.^1–3 The group of patients who experience delayed hemorrhage after EVT remains poorly understood, with multiple classifications^4–6 and explanations^7–9 and deserves further study. To investigate the potential mechanisms of hemorrhages following EVT, we report our rate of hemorrhagic complications (HCs) and their clinical significance and focus on those not related to an arterial lesion secondary to navigation or microcatheter retrieval.     

Temporary Solitaire Stent–Assisted Coiling: A Technique for the Treatment of Acutely Ruptured Wide-Neck Intracranial Aneurysms

BACKGROUND AND PURPOSE:Wide-neck intracranial aneurysms in patients with acute SAH are often challenging lesions to treat by neurosurgical and endovascular approaches. The aim of this study was to investigate the feasibility, safety, and efficacy of the use of temporary Solitaire AB stent–assisted technique with coiling for the treatment of acutely ruptured wide-neck aneurysms without perioperative antiplatelet therapy.MATERIALS AND METHODS:A retrospective review of our endovascular data base identified all patients treated in the acute phase with a temporary stent–assisted technique by use of a fully resheathable Solitaire AB stent and coiling. One-year clinical and angiographic outcomes were evaluated.RESULTS:Eight patients (5 women and 3 men; mean age, 57.5 years) with 8 ruptured wide-neck aneurysms were treated. There were 3 complications without clinical impact. Postoperative complete occlusion was achieved in 5 aneurysms, and 3 had a neck remnant. Three patients had an mRS score of 0, and 1 an mRS score of 3. Among the 4 patients admitted with a World Federation of Neurological Societies grade of V, 1 died, 1 improved to an mRS score of 1, and the other 2 achieved mRS scores of 4 and 5. Five had a stable occlusion, and 2 of the 3 incompletely occluded aneurysms underwent recanalization.CONCLUSIONS:In this small series, temporary placement of the Solitaire AB stent during coiling was a feasible and effective treatment for acutely ruptured wide-neck aneurysms. This technique, avoiding the need for perioperative antiplatelet therapy, could be a valuable option for the treatment of such lesions when the balloon remodeling technique is either not an option or unsuccessful.

Endovascular treatment of ruptured intracranial aneurysms is an established technique,¹ but it can be technically challenging when the neck is large. Numerous devices, including remodeling balloons^2–4 and stents,⁵ have been developed to assist the endovascular treatment of wide-neck aneurysms. However, such techniques carry a great risk of hemorrhagic complications if they are applied in the acute phase of SAH because of the need for dual antiplatelet therapy.^6,7 In the recent review of acutely ruptured aneurysms treated with stent-assisted coiling (SAC) performed by Bodily et al,⁷ clinically significant intracranial hemorrhagic complications occurred in 27 (8%) of 339 patients, including 9 (10%) of 90 patients known to have external ventricular drains (EVDs) who had ventricular drain–related hemorrhages.To avoid the use of antiplatelet therapy in patients with acute SAH, the technique of temporary stent–assisted neck remodeling has been reported with the Enterprise stent (Codman & Shurtleff, Raynham, Massachusetts)⁸ and recently with the support of the Solitaire AB stent (Covidien, Irvine, California) in 3 cases.⁹ However, all patients received aspirin before the procedure, and 1 of 3 patients required antiplatelet therapy after the intervention.⁹ The aim of this study was to investigate the feasibility, safety, and efficacy of the use of temporary Solitaire AB SAC for the treatment of acutely ruptured wide-neck aneurysms without perioperative antiplatelet therapy.     

Morphologic and Hemodynamic Risk Factors in Ruptured Aneurysms Imaged before and after Rupture

BACKGROUND AND PURPOSE:Due to limited information about aneurysm natural history, choosing the appropriate management strategy for an unruptured aneurysm is challenging. By comparing unruptured and ruptured cases, studies have identified a variety of aneurysm morphologic and hemodynamic properties as risk factors for rupture. In this study, we investigated changes in 4 ruptured aneurysms before and after rupture and tested whether previously published risk factors identified a risk before rupture.MATERIALS AND METHODS:A retrospective review of ruptured aneurysms based on the inclusion criteria of documenting angiographic images before and after rupture was performed. Such cases are extremely rare. To minimize hemodynamic influence due to location, we selected 4 cases at the posterior communicating artery. 3D morphologic and hemodynamic analyses were applied to examine qualitative and quantitative risk factors in aneurysms before and after rupture.RESULTS:When we compared aneurysms before and after rupture, all increased in size. Volume, surface area, and morphology changed in both high and low wall shear stress areas. Aneurysm surface ratio, nonsphericity index, and pulsatility index were the only risk factors to consistently identify risk before and after aneurysm rupture for all aneurysms.CONCLUSIONS:Although changes in shape and flow properties were found before and after aneurysm rupture, in this small study, we found that some risk factors were evident as early as 2 years before rupture.

Due to limited information about aneurysm natural history, one of the biggest challenges in clinical aneurysm management is determining the risk of rupture for incidentally found aneurysms. Currently, size guidelines identified by the International Study of Unruptured Intracranial Aneurysms are the dominant criteria guiding treatment decisions.¹ Studies have suggested that the mechanisms underlying aneurysm rupture are multifactorial, and they have likewise identified different types of risk factors. For example, researchers have found that certain aneurysm shapes are risk factors that may associate aneurysm morphology with rupture.^2–4 By analyzing blood flow properties in groups of ruptured and unruptured aneurysms, reports have also shown that certain hemodynamic factors may play an important role in aneurysm rupture.^5–9 However, the morphologic and hemodynamic risk factors analyzed in these studies have generally been identified by analyzing ruptured aneurysms after rupture. Because clinical reports also suggest that aneurysms change due to rupture, how well these risk factors can actually help predict rupture has been controversial.^10–12In general, it is expected that the predictive ability of any aneurysm rupture risk factor will be higher as an aneurysm is closer to rupture. The fundamental rationale in aneurysm risk analysis based on comparing ruptured and unruptured aneurysm groups is that aneurysms that rupture have the same risk characteristics in the unruptured and ruptured states.^5–9,13 In that case, the results obtained by comparing ruptured with unruptured aneurysms can help assess the risk of rupture in as-yet-unruptured aneurysms. However, there are limited studies testing this hypothesis.In this study, we re-examined morphologic and hemodynamic risk factors that have been reported in the literature by using a unique dataset of aneurysms imaged in both their unruptured and ruptured states.^{4,6–8,14–17} Our objective was to investigate morphology and flow properties of aneurysms before and after rupture and find whether previously identified risk factors were present in aneurysms before rupture. We sought to identify risk factors that consistently existed in ruptured aneurysms in both unruptured and ruptured states to guide early determination of aneurysm rupture risk.     

Association between Postprocedural Infarction and Antiplatelet Drug Resistance after Coiling for Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE:Procedure-related thromboembolism is a major limitation of coil embolization, but the relationship between thromboembolic infarction and antiplatelet resistance is poorly understood. The purpose of this study was to verify the association between immediate postprocedural thromboembolic infarction and antiplatelet drug resistance after endovascular coil embolization for unruptured intracranial aneurysm.MATERIALS AND METHODS:This study included 338 aneurysms between October 2012 and March 2015. All patients underwent postprocedural MR imaging within 48 hours after endovascular coil embolization. Antiplatelet drug resistance was checked a day before the procedure by using the VerifyNow system. Abnormal antiplatelet response was defined as >550 aspirin response units and >240 P2Y12 receptor reaction units. In addition, we explored the optimal cutoff values of aspirin response units and P2Y12 receptor reaction units. The primary outcome was radiologic infarction based on postprocedural MR imaging.RESULTS:Among 338 unruptured intracranial aneurysms, 134 (39.6%) showed diffusion-positive lesions on postprocedural MR imaging, and 32 (9.5%) and 105 (31.1%) had abnormal aspirin response unit and P2Y12 receptor reaction unit values, respectively. Radiologic infarction was associated with advanced age (65 years and older, P = .024) only with defined abnormal antiplatelet response (aspirin response units ≥ 550, P2Y12 receptor reaction units ≥ 240). P2Y12 receptor reaction unit values in the top 10th percentile (>294) were associated with radiologic infarction (P = .003). With this cutoff value, age (adjusted odds ratio, 2.29; 95% confidence interval, 1.28–4.08), P2Y12 receptor reaction units (>294; OR, 3.43; 95% CI, 1.53–7.71), and hyperlipidemia (OR, 2.05; 95% CI, 1.04–4.02) were associated with radiologic infarction in multivariate analysis.CONCLUSIONS:Radiologic infarction after coiling for unruptured aneurysm was closely associated with age. Only very high P2Y12 receptor reaction unit values (>294) predicted postprocedural infarction. Further controlled studies are needed to determine the precise cutoff values, which could provide information regarding the optimal antiplatelet regimen for aneurysm coiling.

Endovascular coil embolization is a well-established treatment method for intracranial aneurysms. Recent evidence suggests that this procedure can be considered a first-line treatment for both ruptured and unruptured intracranial aneurysms.^1,2 However, endovascular coil embolization still has major drawbacks, including procedural rupture, thromboembolic complications, and durability issues. Among these shortcomings, thromboembolism is the most common problem.^3–5 To reduce thromboembolic complications, many studies investigated the association between thromboembolism and aneurysm and/or patient factors.^5–8 Previous studies have demonstrated that 30%–60% of endovascular coil embolizations for unruptured aneurysms show ischemic lesions on postprocedural diffusion-weighted images. Although most of the lesions seem to be benign, some could result in permanent neurologic sequelae. Recent studies demonstrated that antiplatelet resistance was associated with ischemic complications after coil embolization and that drug adjustment could lower the risk.^9,10 Still, these results are controversial, and the association between antiplatelet drug resistance and diffusion lesions has not yet been fully elucidated.^11,12Therefore, the purpose of this study was to verify the association between thromboembolic infarction and antiplatelet drug resistance after endovascular coil embolization for unruptured intracranial aneurysms. We also explored other risk factors for thromboembolic complications.     

Treatment of Multiple Intracranial Aneurysms with 1-Stage Coiling

BACKGROUND AND PURPOSE:Although multiple intracranial aneurysms are frequent, determining treatment strategy and methods for them is often complicated. The aim of this study was to evaluate the safety and effectiveness of 1-stage coiling for multiple intracranial aneurysms.MATERIALS AND METHODS:All patients who underwent 1-stage coiling for ≥2 aneurysms were identified from a prospectively registered neurointerventional data base during 10 years. The patient characteristics and clinical and angiographic outcomes at discharge and follow-up were retrospectively evaluated.RESULTS:One hundred sixty-seven patients (male/female ratio, 30:137; mean age, 58 years) with multiple aneurysms (418 aneurysms; mean, 2.5 aneurysms/patient) underwent attempted 1-stage coiling for ≥2 aneurysms (359 aneurysms; mean, 2.1 aneurysms/patient). In 131 patients (78.4%), all detected aneurysms were treated with coiling only. Treatment-related morbidity and mortality at discharge were 1.8% and 0.6% per patient, respectively. Of the 132 patients without subarachnoid hemorrhage, 129 (97.7%) had favorable outcomes (mRS 0–2) at discharge; of the 35 patients with SAH, 27 (77.1%) had favorable outcomes at discharge. Of the 162 patients (97%) for whom clinical follow-up was available (mean, 35.8 months), 154 patients (95.1%) had favorable outcomes. Immediate posttreatment angiography showed complete occlusion in 186 (51.8%) aneurysms, neck remnants in 134 (37.3%), sac remnants in 33 (9.2%), and failure in 6 (1.7%). Of the 262 (73.9%) aneurysms that underwent follow-up imaging (mean, 24.8 months), 244 (93.1%) showed a stable or improved state, with 12 (4.6%) minor and 6 (2.3%) major recurrences.CONCLUSIONS:One-stage coiling of multiple aneurysms seems to be safe and effective, with low morbidity and mortality.

Intracranial aneurysm is the most important cause of subarachnoid hemorrhage, resulting in 8%–20% dependent morbidity and 37%–57% mortality.¹ Strategies and methods for treating intracranial aneurysms have been extensively studied. Multiple intracranial aneurysms are frequent, with a reported incidence of 19%–34% of patients who present with SAH.^2–5 Determining treatment strategy and methods for multiple aneurysms is often complicated. Coiling is currently accepted as a standard treatment for ruptured or unruptured intracranial aneurysms and has been increasingly used, regardless of the location of the intracranial aneurysm.⁶ Nevertheless, while many cases of clipping for multiple aneurysms have been reported,^7–12 there were only 2 small case series using coiling for multiple aneurysms.^13,14 The purpose of this study was to evaluate the safety and effectiveness of 1-stage coiling for multiple intracranial aneurysms.     

One-Year Angiographic Follow-Up after WEB-SL Endovascular Treatment of Wide-Neck Bifurcation Intracranial Aneurysms

BACKGROUND AND PURPOSE:Endovascular coiling of wide-neck intracranial aneurysms is associated with low rates of initial angiographic occlusion and high rates of recurrence. The WEB intrasaccular device has been developed specifically for this indication. To date, there has been no report of the long-term follow-up of a series of patients with aneurysms treated with this type of device, to our knowledge. Our aim was to evaluate a 1-year follow-up of angiographic results in a prospective single-center series of patients treated with the WEB-Single-Layer (SL) device.MATERIALS AND METHODS:All patients treated with the WEB-SL device in our center between August 2013 and May 2014 were prospectively included. One-year angiographic outcomes were assessed. Results at follow-up were graded as complete occlusion, neck remnant, or residual aneurysm.RESULTS:Eight patients with 8 unruptured wide-neck aneurysms were enrolled in this study. Average dome width was 7.5 mm (range, 5.4–10.7 mm), and average neck size was 4.9 mm (range, 2.6–6.5 mm). One-year angiographic follow-up obtained in all aneurysms included 1 complete aneurysm occlusion (12.5%), 6 neck remnants (75%), and 1 aneurysm remnant (12.5%). Of 8 aneurysms, worsening of aneurysm occlusion was observed in 2 (25%) by compression of the WEB device. There was no angiographic recurrence of initially totally occluded aneurysms. No bleeding was observed during the follow-up period.CONCLUSIONS:Endovascular therapy of intracranial aneurysms with the WEB-SL device allows treatment of wide-neck aneurysms with a high rate of neck remnant at 1 year, at least partially explained by WEB compression. Initial size selection and technologic improvements could be an option for optimization of aneurysm occlusion in WEB-SL treatment.

The WEB aneurysm embolization system (Sequent Medical, Aliso Viejo, California) is an intrasaccular braided device specifically developed for endovascular treatment of wide-neck intracranial aneurysms with the goal of disrupting flow at the aneurysm neck and promoting aneurysmal thrombosis without the need for reconstruction of the entire parent artery segment with a stent. Several types of WEB devices are currently available¹: the WEB-Dual-Layer (DL), which is made of 2 layers held together and creating 2 compartments, and the WEB-Single-Layer (SL), which is a single-layer device creating only 1 compartment. Only a few studies on the treatment of intracranial aneurysms by using the WEB-DL have been published,^2–5 and to date, only a single published article on aneurysms treated with WEB-SL reported a series including any anatomic follow-up.⁶ We recently published the 6-month clinical and anatomic outcomes of WEB-SL endovascular treatment.⁷The purpose of this study was to evaluate the 1-year angiographic results of patients managed with the WEB-SL device in a prospective single-center series.     

Simultaneous Endovascular Treatment of Ruptured Cerebral Aneurysms and Vasospasm

ObjectiveThe management of patients with ruptured cerebral aneurysms and severe vasospasm is subject to considerable controversy. We intended to describe herein an endovascular technique for the simultaneous treatment of aneurysms and vasospasm.ResultsThis technique was applied to 11 ruptured aneurysms accompanied by vasospasm (anterior communicating artery, 6 patients; internal carotid artery, 2 patients; posterior communicating and middle cerebral arteries, 1 patient each). Aneurysmal occlusion by coils and nimodipine-induced angioplasty were simultaneously achieved, resulting in excellent outcomes for all patients, and there were no procedure-related complications. Eight patients required repeated nimodipine infusions.ConclusionOur small series of patients suggests that the simultaneous endovascular management of ruptured cerebral aneurysms and vasospasm is a viable approach in patients presenting with subarachnoid hemorrhage and severe vasospasm.     

微弹簧圈血管内介入治疗颅内动脉瘤

目的总结颅内动脉瘤血管内介入治疗的经验,探讨微弹簧圈栓塞颅内动脉瘤的技巧、效果及相关并发症的防治。方法回顾性分析我院介入治疗颅内动脉瘤31例,32个动脉瘤的临床资料,其中单纯用弹簧圈栓塞25例,宽颈动脉瘤球囊辅助弹簧圈栓塞4例,支架结合弹簧圈栓塞1例,载瘤动脉闭塞1例。结果栓塞程度:致密栓塞27例,疏松栓塞3例,闭塞载瘤动脉1例;术中动脉瘤破裂3例,术后完全康复22例,不同程度神经功能障碍8例,死亡1例。结论电解脱弹簧圈栓塞颅内动脉瘤,具有微创、安全、效果可靠等优点。选择合适的技术和方法,对提高栓塞率,减少并发症具有重要的意义。     

Endovascular Coil Embolization of Very Small Intracranial Aneurysms

Objective

We aimed to evaluate the results of endovascular coil embolization for very small aneurysms (≤ 3 mm).

Materials and Methods

Between March 2005 and December 2008, a total of 31 very small aneurysms in 30 patients were treated by coil embolization. Of the 31 aneurysms, five (16%) were ruptured, as opposed to 26 (84%) that were not. We assessed the procedural complications, immediate angiographic outcome after coiling, clinical outcome, and follow-up MR angiography (MRA).

Results

Two thromboembolic complications occurred during the procedure, but did not lead to any persistent neurologic deficit. No procedural aneurysmal rupture was observed and procedure-related morbidity and mortality were both 0%. Occlusion was adequate in 25 aneurysms (81%) and incomplete in six aneurysms (19%). The clinical outcomes of five patients with ruptured aneurysms were good (Glasgow outcome scale ≥ 4), with no bleeding of the treated aneurysms during a mean follow-up period of 13.3 months. On 27 follow-up MRA, there was no recurrence, and the five incompletely occluded aneurysms showed a spontaneous amelioration resulting in an adequate occlusion.

Conclusion

Coil embolization of very small aneurysms is technically feasible with good results. The long-term efficacy and the potential as a standard treatment strategy remain to be determined by randomized large trials.     

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis

BACKGROUND:Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear.PURPOSE:To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices.DATA SOURCES:Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion.STUDY SELECTION:One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion.DATA ANALYSIS:Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05).DATA SYNTHESIS:Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001).LIMITATIONS:Observational studies and case reports may be affected by reporting bias.CONCLUSIONS:Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Endovascular treatment of intracranial aneurysms with detachable coils was first described in 1991¹ and has since become an established method of aneurysm treatment. The International Study of Unruptured Intracranial Aneurysms² and Analysis of Treatment by Endovascular Approach of Nonruptured Aneurysms (ATENA)³ demonstrated the effectiveness and relative safety of endovascular coiling for unruptured aneurysms. Similarly, the International Subarachnoid Aneurysm Trial (ISAT), the Barrow Ruptured Aneurysm Trial, and other trials^4–7 have demonstrated the effectiveness and relative safety of endovascular coiling in ruptured aneurysms.In recent years, flow diverters (FDs) have emerged as a new endovascular treatment option for intracranial aneurysms. FDs are a reconstructive treatment in which altered flow within an aneurysm induces gradual remodeling and eventual thrombosis of the aneurysm. Several studies have demonstrated good safety and efficacy of FDs for the treatment of unruptured intracranial aneurysms,^8–17 though the safe use of these devices requires the use of dual antiplatelet therapy.^18–20Understandably, the need for antiplatelet medications and the delayed nature of aneurysm thrombosis have tempered enthusiasm for using FDs for ruptured aneurysms. Nevertheless, several reports have described the use of FDs to treat recently ruptured aneurysms, particularly those that are difficult to treat by other endovascular or open microsurgical techniques.In this meta-analysis, we review the outcomes associated with the use of FDs for the treatment of ruptured intracranial aneurysms. Specifically, we review aneurysm characteristics and endovascular treatment strategies in relation to the rates of angiographic occlusion and good clinical outcome, with the overall goal of guiding FD use in ruptured aneurysms when other treatment options are not viable.     

Risk Factors for Growth of Intracranial Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:Understanding risk factors for intracranial aneurysm growth is important for patient management. We performed a meta-analysis examining risk factors for intracranial aneurysm growth in longitudinal studies and examined the association between aneurysm growth and rupture.MATERIALS AND METHODS:We searched the literature for longitudinal studies of patients with unruptured aneurysms. We examined the associations of demographics, multiple aneurysms, prior subarachnoid hemorrhage, family history of aneurysm or subarachnoid hemorrhage, smoking, and hypertension; and aneurysm shape, size, and location with aneurysm growth. We studied the association between aneurysm growth and rupture. A meta-analysis was performed by using a random-effects model by using summary statistics from included studies.RESULTS:Twenty-one studies including 3954 patients with 4990 aneurysms with 13,294 aneurysm-years of follow-up were included. The overall proportion of growing aneurysms was 3.0% per aneurysm-year (95% CI, 2.0%–4.0%). Patient risk factors for growth included age older than 50 years (3.8% per year versus 0.9% per year, P < .01), female sex (3.2% per year versus 1.3% per year, P < .01), and smoking history (5.5% per year versus 3.5% per year, P < .01). Characteristics associated with higher growth rates included cavernous carotid artery location (14.4% per year), nonsaccular shape (14.7% per year versus 5.2% per year for saccular, P < .01), and aneurysm size (P < .01). Aneurysm growth was associated with a rupture rate of 3.1% per year compared with 0.1% per year for stable aneurysms (P < .01).CONCLUSIONS:Observational evidence provided multiple clinical and anatomic risk factors for aneurysm growth, including age older than 50 years, female sex, smoking history, and nonsaccular shape. These findings should be considered when counseling patients regarding the natural history of unruptured intracranial aneurysms.

Unruptured intracranial aneurysms have a fairly high prevalence in the general population, with estimates of aneurysm prevalence ranging from 2% to 8%.^1,2 However, the incidence of subarachnoid hemorrhage is substantially lower, estimated to be 10–30 per 100,000 per year.³ In addition to rupture, aneurysms can result in substantial morbidity secondary to cranial nerve palsies, headache, and even anxiety.⁴ Overall, there has been a trend toward increased treatment of unruptured intracranial aneurysms with surgical clipping and endovascular coiling.⁵ With improvement in operative and endovascular techniques as well as postoperative care, the morbidity and mortality related to these procedures has decreased with time.⁶ When counseling patients with unruptured aneurysms, many practitioners discuss the risks of surgical or endovascular treatment in the context of the natural history of their aneurysms.⁴ Results from long-term follow-up studies, such as the International Study of Unruptured Intracranial Aneurysms, the Small Unruptured Intracranial Aneurysm Verification study (UCAS), are often used in discussing the natural history of unruptured aneurysms with patients.^7–11Risk factors for aneurysm growth are relatively understudied compared with those of aneurysm rupture. However, many longitudinal observational studies may not follow patients long enough to witness aneurysm rupture but will see aneurysm growth during their short follow-up time. In addition, aneurysms that grow on surveillance imaging are generally treated; this factor potentially decreases the rupture rate in many longitudinal studies. Because growth itself may be a risk factor for rupture, an understanding of the clinical and anatomic risk factors for aneurysm growth is important.¹² Therefore, we performed a systematic review and meta-analysis of all published studies examining the clinical and anatomic risk factors for aneurysm growth. In addition, we performed a separate analysis to determine the rupture rate of growing aneurysms. We hypothesized that factors known to be associated with aneurysm rupture (ie, Japanese or Finnish population, hypertension, older age, increasing aneurysm size, previous SAH, and location) would also be associated with growth.     

Thromboembolic Complications in Patients with Clopidogrel Resistance after Coil Embolization for Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE:Antiplatelet resistance is known to be associated with symptomatic ischemic complication after endovascular coil embolization. The purpose of our study was to evaluate the relationship between antiplatelet resistance and clinically silent thromboembolic complications using DWI in patients who underwent coil embolization for unruptured intracranial aneurysm.MATERIALS AND METHODS:Between October 2011 and May 2013, 58 patients with 62 unruptured aneurysms who were measured for antiplatelet response using VerifyNow assay and underwent elective coil embolization for an unruptured aneurysm with posttreatment DWI were enrolled. Diffusion-positive lesions were classified into 3 groups according to the number of lesions (n = 0 [grade 0], n < 6 [grade I], and n ≥ 6 [grade II]). The relationship between antiplatelet resistance and diffusion-positive lesions was analyzed.RESULTS:Sixty-two endovascular coiling procedures were performed on 58 patients. Clopidogrel resistance was revealed in 23 patients (39.7%) and diffusion-positive lesions were demonstrated in 28 patients (48.3%); these consisted of 19 (32.8%) grade I and 9 (15.5%) grade II lesions. Clopidogrel resistance was not relevant to the development of any diffusion-positive lesion (grade I and II, P = .789) but was associated with the development of multiple diffusion-positive lesions (grade II, P = .002). In the logistic regression prediction model, clopidogrel resistance showed significant correlation with the development of grade II lesions (P = .001).CONCLUSIONS:Multiple diffusion-positive lesions (≥6 in number) occurred more frequently in patients with clopidogrel resistance after endovascular coiling for unruptured aneurysms.

Since it was demonstrated that clopidogrel resistance is associated with thromboembolic events after cardiovascular stent placement, many studies in patients undergoing neurovascular stent placement have revealed a similar relationship between antiplatelet drug resistance and thromboembolic complications.^1,2 Furthermore, recently published reports have documented that clopidogrel resistance had an effect on the occurrence of symptomatic ischemic infarcts in patients undergoing endovascular treatment with or without adjunctive devices for intracranial aneurysms.^3,4The widespread and routine application of DWI after coil embolization has revealed that clinically silent thromboembolic phenomena occur in up to one-third of cases.⁵ Several clinical and procedural factors have been proposed as being associated with those postprocedural diffusion abnormalities.⁶ However, the relationship between the antiplatelet drug reactivity and the thromboembolic complication delineated on DWI has not been well-characterized in patients undergoing coil embolization. The aim of the present study was to evaluate the frequency of posttreatment diffusion-positive lesions associated with coil insertion for treatment of unruptured intracranial aneurysms in patients with antiplatelet drug resistance. In addition, other clinical, aneurysmal, and procedural factors were assessed to reveal the association with the occurrence of posttreatment diffusion-positive lesions.     

Endovascular Treatment of Very Small Intracranial Aneurysms: Meta-Analysis

BACKGROUND AND PURPOSE:Outcomes of endovascular treatment of very small intracranial aneurysms are still not well-characterized. Recently, several series assessing coil embolization of tiny aneurysms have presented new promising results. Thus, we performed a systematic review and meta-analysis of studies evaluating endovascular treatment of very small intracranial aneurysms.MATERIALS AND METHODS:We conducted a computerized search of Scopus, Medline, and the Web of Science for studies on endovascular treatment of very small (≤3 mm in diameter) intracranial aneurysms published between January 1996 and May 2015. Using a random-effects model, we evaluated clinical and angiographic outcomes.RESULTS:Twenty-two studies with 1105 tiny aneurysms (844 ruptured and 261 unruptured) endovascularly treated were included. Postoperative and long-term complete occlusion was achieved in 85% (95% CI, 78%–90%) and 91% (95% CI, 87%–94%) of aneurysms, respectively. The recanalization rate was 6% (95% CI, 4%–11%) and retreatment occurred in 7% (95% CI, 5%–9%) of cases. Seventy-nine percent (95% CI, 64%–89%) of patients had good neurologic outcome at long-term follow-up. Intraprocedural rupture occurred in 7% (95% CI, 5%–9%) of the coiling procedures, while thromboembolic complications occurred in 4% (95% CI, 3%–6%).CONCLUSIONS:Coil embolization of very small intracranial aneurysms can be performed safely and effectively. In the case of unruptured aneurysms, procedure-related complications are not negligible. Patients and providers should consider such risks when engaged in a shared decision-making process.

Endovascular treatment is now the standard of care for most intracranial aneurysms (IAs).^1,2 Despite endovascular treatment being safe with low morbidity and mortality rates, in certain groups of aneurysms, a detailed risk-benefit assessment of this treatment must be considered.³ Coil embolization of very small IAs (≤3 mm) is particularly challenging due to the thin fragile wall of small IAs, with limited space to obtain a stable microcatheter position for coil deployment.^4–6 In the Barrow Ruptured Aneurysm Trial, very small aneurysm size was one of the main reasons for the high crossover rate from the coiling to the clipping group.² A previous meta-analysis that included only 7 studies observed a relatively high complication rate, especially in terms of periprocedural rupture risk.⁷ Since then, several technologic improvements, including better microcatheters and steerable soft microguidewires, compliant and easier-to-navigate balloons, and the availability of newer distal access catheters and very small endovascular coils have been developed, which may have enhanced our ability in coiling very small aneurysms. Since publication of the previous meta-analysis, many recent series have outlined results and complications in this specific subset of aneurysms.In an attempt to examine the current safety and efficacy of endovascular treatment of tiny intracranial aneurysms, we performed an updated systematic review and meta-analysis of the literature addressing the endovascular treatment of very small intracranial aneurysms. We also compared results from studies included in a previously published meta-analysis from 2010⁷ with more recently published studies to determine whether there have been improvements in outcomes with time. We hypothesized that recently published studies would demonstrate lower intraoperative rupture rates and higher rates of aneurysm occlusion.