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.     

Endovascular Treatment of Anterior Communicating Artery Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:Endovascular therapy has become an acceptable alternative to traditional clipping for the management of intracranial aneurysms. However, a limited number of studies have examined outcomes and complications specific to embolization of anterior communicating artery aneurysms.MATERIALS AND METHODS:A systematic review of the literature was conducted with the use of multiple data bases to identify reports on endovascular treatment of anterior communicating artery aneurysms between 1994 and 2012. Angiographic results, clinical outcomes, and complication rates were pooled across studies by using random-effects meta-analysis with subgroup analysis of outcomes by rupture status and time trend stratification.RESULTS:Fourteen studies, consisting of 1552 treated anterior communicating artery aneurysms, were included in this meta-analysis. The rate of immediate and long-term complete and near-complete angiographic occlusion was 88% (95% CI = 81–93%) and 85% (95% CI = 78–90%), respectively. Intraprocedural rupture rate was 4% (95% CI = 3–6%). The re-bleeding rate was 2% (95% CI = 1–4%) and the retreatment rate was 7% (95% CI = 5–12%). Morbidity or mortality caused by perioperative stroke occurred at a 3% (95% CI = 2–6%) rate. Overall procedure-related morbidity and mortality were 6% (95% CI = 4–8%) and 3% (95% CI = 2–4%), respectively. Outcomes did not differ between ruptured and unruptured aneurysms, nor did outcomes change over time, though these latter subanalyses were relatively underpowered.CONCLUSIONS:Endovascular therapy for anterior communicating artery aneurysms is associated with a high rate of complete angiographic occlusion. However, the procedure-related permanent morbidity and mortality are not negligible for aneurysms in this location.

The anterior communicating artery (AcomA) is the most common location for intracranial aneurysms in most series, and rupture of aneurysms in this location accounts for approximately 40% of aneurysmal subarachnoid hemorrhages in adults.^1–5 Aneurysms of the AcomA can be technically challenging from a surgical perspective because of complex regional flow dynamics, frequent anatomic variations, variable geometry, and the presence of critical perforators.^1,6–10 In the past 2 decades, the inherently less invasive endovascular approach has emerged as a feasible and acceptable treatment option for AcomA aneurysms.^11–14 Continual advancements in endovascular technique and adjuvant devices have led to an enlarging proportion of patients with AcomA aneurysms who are successfully treated with coil embolization.^10,11,15,16 A limited number of case series have detailed the clinical outcomes, angiographic results, and procedure-related complications specific for endovascular treatment in this location.^{10–13,15–24} We performed a systematic review of the published literature to better define safety and efficacy profiles for coil embolization of AcomA aneurysms beyond single-center experiences.     

Diffusion-Weighted Imaging–Detected Ischemic Lesions following Endovascular Treatment of Cerebral Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:Endovascular treatment of intracranial aneurysms is associated with the risk of thromboembolic ischemic complications. Many of these events are asymptomatic and identified only on diffusion-weighted imaging. We performed a systematic review and meta-analysis to study the incidence of DWI positive for thromboembolic events following endovascular treatment of intracranial aneurysms.MATERIALS AND METHODS:A comprehensive literature search identified studies published between 2000 and April 2016 that reported postprocedural DWI findings in patients undergoing endovascular treatment of intracranial aneurysms. The primary outcome was the incidence of DWI positive for thromboembolic events. We examined outcomes by treatment type, sex, and aneurysm characteristics. Meta-analyses were performed by using a random-effects model.RESULTS:Twenty-two studies with 2148 patients and 2268 aneurysms were included. The overall incidence of DWI positive for thromboembolic events following endovascular treatment was 49% (95% CI, 42%–56%). Treatment with flow diversion trended toward a higher rate of DWI positive for lesions than coiling alone (67%; 95% CI, 46%–85%; versus 45%; 95% CI, 33%–56%; P = .07). There was no difference between patients treated with coiling alone and those treated with balloon-assisted (44%; 95% CI, 29%–60%; P = .99) or stent-assisted (43%; 95% CI, 24%–63%; P = .89) coiling. Sex, aneurysm rupture status, location, and size were not associated with the rate of DWI positive for lesions.CONCLUSIONS:One in 2 patients may have infarcts on DWI following endovascular treatment of intracranial aneurysms. There is a trend toward a higher incidence of DWI-positive lesions following treatment with flow diversion compared with coiling. Patient demographics and aneurysm characteristics were not associated with DWI-positive thromboembolic events.

Coil embolization and flow diversion have proved highly efficacious options for the endovascular treatment of intracranial aneurysms. However, both techniques are associated with potential periprocedural complications, including aneurysm rupture, transient ischemic attacks, and ischemic stroke. Small, silent infarcts caused by thromboemboli are often seen on postprocedural diffusion-weighted imaging. While many of these lesions remain ostensibly asymptomatic, the long-term effects of such tiny infarcts remain unclear.^1–3Previous studies have reported that the rate of ischemic lesions on postoperative DWI ranges from 10% to 77% following coil embolization^4–15 and 51% to 63% following therapy with flow diversion.^16–19 However, baseline clinical and angiographic risk factors for postoperative DWI lesions, to our knowledge, have not been fully elucidated previously. We performed a systematic review and meta-analysis for the following: 1) to determine the overall incidence of perioperative infarcts on DWI in patients undergoing endovascular treatment of intracranial aneurysms; and 2) to demonstrate the relationship between treatment type, patient demographics, and aneurysm characteristics with postoperative infarcts on DWI.     

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.     

Complications of Endovascular Repair of Abdominal Aortic Aneurysms: A Review

The endovascular procedure for repair of abdominal aortic aneurysms has had an enormous impact on the treatment of this challenging disease. Complications, however, do occur and it is important to have a thorough understanding of the array of complications and appropriate management strategies. In this review of endovascular complications, we describe early and late complications paying particular attention to preventive, treatment and surveillance strategies.     

Geographic Differences in Endovascular Treatment and Retreatment of Cerebral Aneurysms

BACKGROUND AND PURPOSE:Comparing outcomes between endovascular aneurysm coiling trials can be difficult because of heterogeneity in patients and end points. We sought to understand the impact of geography on aneurysm retreatment in patients enrolled in the Matrix and Platinum Science Trial.MATERIALS AND METHODS:Post hoc analysis was performed on data from the Matrix and Platinum Science trial. Patients were stratified as either North American or international. Baseline patient demographics, comorbidities, aneurysm characteristics, procedural complications, and clinical and angiographic outcomes were compared.RESULTS:We evaluated 407 patients from 28 North American sites and 219 patients from 15 international sites. Patient demographics differed significantly between North American and international sites. Aneurysms were well occluded postprocedure more often at international than North American sites (P < .001). Stents were used significantly more often at North American sites (32.7% [133 of 407]) compared with international sites (10.0% [22 of 219]; P < .001). At 455 days, there was no difference in the proportion of patients alive and free of disability (P = .56) or with residual aneurysm filling (P = .10). Ruptured aneurysms were significantly more likely to have been retreated at North American sites within the first year (P < .001) and at 2 years (P < .001). Among all patients for whom the treating physician believed there to be Raymond 3 aneurysm filling at follow-up, absolute rates of retreatment at international and North American sites were similar by 2-year follow-up.CONCLUSIONS:Data from the Matrix and Platinum Science Trial demonstrate that aneurysm retreatment occurs with different frequency and at different times in different regions of the world. This trend has critical value when interpreting trials reporting short-term outcomes, especially when judgment-based metrics such as retreatment are primary end points that may or may not take place within the defined study follow-up period. Though these variations can be controlled for and balanced within a given randomized trial, such differences in practice patterns must be accounted for in any attempt to compare outcomes between different trials. Despite these differences, endovascular-treated intracranial aneurysms around the world have similar clinical outcomes.

The International Subarachnoid Aneurysm Trial^1,2 was the landmark prospective randomized trial demonstrating the safety and effectiveness of endovascular treatment of ruptured aneurysms compared with surgical clipping. More recently, results from the Barrow Ruptured Aneurysm Trial³ further support coiling as a treatment technique associated with good patient outcomes comparable with clipping in the setting of SAH. Moreover, the results of several recently published multinational randomized controlled trials^4–6 demonstrated ruptured and unruptured aneurysms can be safely and effectively treated by using various coil types. Many comparisons generalizing results of these various trials have been made. However, comparing outcomes between trials can be difficult and misleading because of different trial designs and patient populations.⁷ Analyses of subgroups from different trials cannot overcome these problems.The very low bleeding or rebleeding rates of treated aneurysms has led most trial investigators to use angiographic outcomes to compare device performance. However, there are no agreed-upon standards for acceptable angiographic outcomes. Recently, the value of target aneurysm recurrence was explored as a new clinically relevant composite end point in a large-scale multicenter randomized trial comparing outcomes of patients with intracranial saccular aneurysms treated with 2 different embolic coil types.^4,8,9 In this study, target aneurysm recurrence was defined as clinically relevant aneurysm recurrence resulting in target aneurysm re-intervention, rupture/rerupture, and/or death from an unknown cause. The advantage of this end point is that it is definitive that the event has happened and that these events are of clear relevance to the patient. The disadvantage of these end points is the variability of the decision to retreat because physician judgment often varies with the training, economic incentives, and regulatory structure of the local health system.Both angiographic assessments and the decision to retreat aneurysms are subjective, leaving tremendous opportunity for individual or regional factors to influence trial results. We sought to understand the impact of geography on aneurysm retreatment in patients randomized in the Matrix and Platinum Science Trial.     

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.     

Treatment of Middle Cerebral Artery Aneurysms with Flow-Diverter Stents: A Systematic Review and Meta-Analysis

BACKGROUND:The safety and efficacy of flow-diversion treatment of MCA aneurysms have not been well-established.PURPOSE:Our aim was to evaluate angiographic and clinical outcomes after flow diversions for MCA aneurysms.DATA SOURCES:A systematic search of PubMed, MEDLINE, and Embase was performed for studies published from 2008 to May 2017.STUDY SELECTION:According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we selected studies with >5 patients describing angiographic and clinical outcomes after flow-diversion treatment of MCA aneurysms.DATA ANALYSIS:Random-effects meta-analysis was used to pool the following outcomes: aneurysm occlusion rate, procedure-related complications, rupture rate of treated aneurysms, and occlusion of the jailed branches.DATA SYNTHESIS:Twelve studies evaluating 244 MCA aneurysms were included in this meta-analysis. Complete/near-complete occlusion was obtained in 78.7% (95% CI, 67.8%–89.7%) of aneurysms. The rupture rate of treated aneurysms during follow-up was 0.4% per aneurysm-year. The rate of treatment-related complications was 20.7% (95% CI, 14%–27.5%), and approximately 10% of complications were permanent. The mortality rate was close to 2%. Nearly 10% (95% CI, 4.7%–15.5%) of jailed arteries were occluded during follow-up, whereas 26% (95% CI, 14.4%–37.6%) had slow flow. Rates of symptoms related to occlusion and slow flow were close to 5%.LIMITATIONS:Small and retrospective series could affect the strength of the reported results.CONCLUSIONS:Given the not negligible rate of treatment-related complications, flow diversion for MCA aneurysms should be considered an alternative treatment when traditional treatment methods are not feasible. However, when performed in this select treatment group, high rates of aneurysm occlusion and protection against re-rupture can be achieved.

Flow-diverter stents have become a feasible and effective treatment for most intracranial aneurysms, and their indications are constantly extended, including distal aneurysm locations.^1–3 Commonly, middle cerebral artery aneurysms present with a particularly complex anatomy because of the frequency of wide-neck configurations with incorporating MCA branches. Endovascular treatment of MCA aneurysms can be technically more challenging, and in many institutions, surgical treatment is considered the first option because of the high rate of long-term occlusion with low surgical morbidity.⁴ However, with the improvement of angiographic images, increased operator experience, and the use of more complex techniques, an increasing number of MCA aneurysms are treated with endovascular techniques.¹ Recently, flow diversion has been used as an alternative technique for complex wide-neck MCA aneurysms, incorporating ≥1 side branch or in cases of previous endovascular or surgical failure.^5–14 However, the role of flow diversion in this location is controversial, and the efficacy and safety of this technique remain unclear. We performed a systematic review and meta-analysis of all published series examining flow diversions for the treatment of MCA aneurysms with the aim of clarifying the following: 1) aneurysm occlusion rate, 2) treatment-related complications and clinical outcome, and 3) the fate of the MCA side branch covered with the device.     

Endovascular Treatment of Femoropopliteal Aneurysms: A Five-Year Experience

Purpose To assess the effectiveness of endovascular treatment of femoropopliteal aneurysms (FPAs). Methods In the last 5 years, we have treated 17 FPAs (diameter 21–75 cm, mean 38.4 cm; length 27–100 cm, mean 72.5 cm) in 15 patients (age 57–80 years, mean 70.9 years). The diagnosis was obtained by color Doppler ultrasound (CDU) and the procedure was planned by CT angiography (CTA) and preprocedural angiography. Eight FPAs were excluded with only one stent-graft; in 8 patients, two stent-grafts were positioned; and in 1 patient, three stent-grafts were used. In 14 cases we used a Wallgraft endoprosthesis, in 2 cases a Hemobahn, and in 1 case an Excluder contralateral leg. The patients were followed up with CDU and occasionally with CTA. Results Immediate technical success was obtained in 17 of 17 cases (100%). One patient died during the first year. During a mean follow-up of 26.9 months (range 3–60 months) we observed 6 of 16 (38%) stent-graft occlusions (3 of which were recanalized with locoregional thrombolysis and 3 with mechanical thrombectomy). Two stent-grafts were patent at 12 and 24 months. Four patients experienced subsequent occlusions and recanalizations until corrected by surgical bypass (1 at 14 months, 2 at 18 months, and 1 at 36 months). Therefore the primary patency was 63% and assisted patency was 73%. Conclusion The endovascular approach is a minimally invasive treatment option for FPAs. Moreover endovascular stent-grafting does not necessarily preclude conventional surgical repair, but it can delay it. Longer follow-up will be needed to determine the long-term patency rate.     

Endovascular Treatment of Middle Cerebral Artery Aneurysms for 120 Nonselected Patients: A Prospective Cohort Study

BACKGROUND AND PURPOSE:Multiple technologies have developed the endovascular approach to MCA aneurysms. We assess the safety and the efficacy of a systematic endovascular approach in nonselected patients with MCA aneurysms and determine predictors of treatment outcomes.MATERIALS AND METHODS:We analyzed data collected between January 2007 and January 2012 in a prospective clinical registry. All patients with MCA aneurysms treated by means of the endovascular approach were included. A multivariate analysis was conducted to identify predictors of complications, recanalization, and outcome.RESULTS:A total of 120 patients with 131 MCA aneurysms were included. Seventy-nine patients (65.8%) were treated electively and 41 (34.2%) in the setting of subarachnoid hemorrhage. Thirty-three of 131 aneurysms (25.2%) were treated with simple coiling, 79 aneurysms (60.3%) with balloon-assisted coiling, and 19 aneurysms (14.5%) with stent-assisted coiling. Complications occurred in 13.7% of patients. Stent-assisted coiling was significantly associated with more complications (P = .002; OR: 4.86; 95% CI, 1.60–14.72). At 1 month after treatment, both the permanent morbidity (mRS ≤2) and mortality rates were 3.3%, without any significant difference according to the endovascular techniques. Mean angiographic follow-up was 16.3 months. The rate of recanalization was 15.6% without a statistical difference, according to the technique. Larger aneurysms were a predictor of recanalization (P = .016; OR: 1.183; 95% CI, 1.02–1.36). Retreatment was performed in 10 of 131 aneurysms (7.6%).CONCLUSIONS:Even though stent-assisted coiling significantly increases the risk of procedural complications, endovascular treatment of MCA aneurysms is safe, effective, and provides durable aneurysm closure in nonselected patients.

Endovascular treatment (EVT) of intracranial aneurysms is an established technique for both ruptured and unruptured aneurysms.^1,2 Nevertheless, many institutions still use surgical clipping (rather than coiling) as the first treatment for MCA aneurysms because they are accessible, even with complex anatomic features, which is not usually considered suitable for EVT with standard coiling.^3–5 In a systematic review of endovascular series of MCA aneurysms, the rates of combined permanent morbidity and mortality were 5.1% and 6.0% for unruptured and ruptured aneurysms, respectively.⁶ However, most of these series were highly focused on selected patients.^7–10 To date, with the advent of new endovascular tools such as balloons and stents designed specifically for the intracranial circulation, MCA aneurysms can be managed by means of the endovascular approach. However, the safety and efficacy of EVT for all patients are not well known yet.We assess the safety and the efficacy of a systematic endovascular approach in nonselected patients with MCA aneurysms in a prospective cohort. Predictors of complications, recanalization, and clinical outcome were determined.     

Endovascular Treatment of Internal Carotid Artery Bifurcation Aneurysms: A Single-Center Experience and a Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:Endovascular coiling of internal carotid artery bifurcation aneurysms can be challenging due to unfavorable morphologic features. With improvements in endovascular techniques, several series have detailed the results and complications of endovascular treatment of aneurysms at this location. We performed a systematic review and meta-analysis of published series on the endovascular treatment of ICA bifurcation aneurysms, including a tertiary referral center experience.MATERIALS AND METHODS:We performed a comprehensive literature search for reports on contemporary endovascular treatment of ICA bifurcation aneurysms from 2000 to 2013, and we reviewed our experience. We extracted information regarding periprocedural complications, procedure-related morbidity and mortality, immediate angiographic outcome, long-term clinical and angiographic outcome, and retreatment rate. Event rates were pooled across studies by using random-effects meta-analysis.RESULTS:Including our series of 37 patients, 6 studies with 158 patients were analyzed. Approximately 60% of the aneurysms presented as unruptured; 88.0% (95% CI, 68.0%–96.0%) of aneurysms showed complete or near-complete occlusion at immediate postoperative angiography compared with 82.0% (95% CI, 73.0%–88.0%) at last follow-up. The procedure-related morbidity and mortality were 3.0% (95% CI, 1.0%–7.0%) and 3.0% (95% CI, 1.0%–8.0%), respectively. The retreatment rate was 14.0% (95% CI, 8.0%–25.0%). Good neurologic outcome was achieved in 93.0% (95% CI, 86.0%–97.0%) of patients.CONCLUSIONS:Endovascular treatment of ICA bifurcation aneurysms is feasible and effective and is associated with high immediate angiographic occlusion rates. However, retreatment rates and procedure-related morbidity and mortality are non-negligible.

Internal carotid artery bifurcation aneurysms represent between 2.4% and 4% of all intracranial aneurysms.^1–4 The presence of multiple perforators in this area along with the angle of origin (often skewed toward the MCA or the anterior cerebral artery primarily) can make treatment challenging.³ Additionally, the increased hemodynamic stress at this level translates into a higher rate of recurrence compared with aneurysms in other locations.^4,5 Several studies have focused on the surgical management of ICA bifurcation aneurysms.^2,3,6–10 However, to our knowledge, there is limited evidence regarding their treatment by using endovascular techniques. To better understand the safety and efficacy of endovascular treatment for ICA bifurcation aneurysms, we report both our own experience and the results of a meta-analysis of the literature.     

pCONus Device for the Endovascular Treatment of Wide-Neck Middle Cerebral Artery Aneurysms

BACKGROUND AND PURPOSE:Endovascular treatment of bifurcation middle cerebral artery aneurysms with a wide neck could be challenging, and many lesions are still treated by a surgical approach. The pCONus is a newly emerging device for wide-neck bifurcation intracranial aneurysms. To date, a single report on the treatment of intracranial aneurysms including all locations has been published. We report our experience with pCONus in the treatment of wide-neck MCA aneurysms.MATERIALS AND METHODS:MCA aneurysms treated with pCONus in 4 European centers were retrospectively reviewed.RESULTS:Forty MCA aneurysms (mean dome size, 7.7 mm; mean neck size, 5.6 mm) were treated in 40 patients (mean age, 62 years). Aneurysm coiling was performed after deployment of 1 pCONus in 95% (38/40) of cases and after deployment of 2 pCONus devices in 5% (2/40). No procedural angiographic complications were observed. Reversible neurologic complications were noted in 5% (2/40), and permanent neurologic complication, in 2.5% (1/40) at 1 month. There was no mortality. No aneurysms bled or rebled after treatment. Immediate angiographic results were complete aneurysm occlusion in 25% (10/40), neck remnant in 47.5% (19/40), and aneurysm remnant in 27.5% (11/40). Follow-up (mean, 6.8 months) was available for 33 aneurysms (82.5%). Stable or improved results were observed in all except 3 cases, including 48.5% complete occlusions (16/33), 30.3% neck remnants (10/33), and 21.2% aneurysm remnants (7/33). There was no in-stent stenosis or jailed branch occlusion. There was no angiographic recurrence of initially totally occluded aneurysms.CONCLUSIONS:MCA aneurysms with a wide neck are amenable to treatment with pCONus.

Although the superiority of endovascular treatment compared with surgery appears unaffected by aneurysm location in the randomized International Subarachnoid Aneurysm Trial,¹ management of middle cerebral artery aneurysms remains a matter of debate. Nevertheless many institutions still use surgical clipping as the first treatment for MCA aneurysms.^2,3 Balloon and stent-assisted techniques have widened the indications for endovascular treatment of MCA aneurysms with a wide neck and/or unfavorable anatomy that were otherwise unsuitable for coiling.^4,5 However, the risk of procedure-related morbidity and mortality is not negligible, especially with double-stent placement in Y and X configurations.^4,6,7 The widespread adoption of endovascular treatment for MCA aneurysms with unfavorable anatomy requires an improvement of the safety of the endovascular approach. A new device, the pCONus aneurysm implant (phenox, Bochum, Germany), has recently been developed to improve the safety of endovascular treatment of these challenging aneurysms. To date, a single published article on intracranial aneurysms treated with pCONus reported a series including some cases of MCA aneurysms.⁸ The aim of this study was to evaluate the results in the treatment of wide-neck MCA aneurysms with the pCONus device.     

Endovascular Treatment of 300 Consecutive Middle Cerebral Artery Aneurysms: Clinical and Radiologic Outcomes

BACKGROUND AND PURPOSE:There is controversy as to the best mode of treating MCA aneurysms. We report the results of a large endovascular series of patients treated at our center.MATERIALS AND METHODS:This study was a retrospective analysis of a prospectively acquired data base. All patients with saccular MCA aneurysms treated between November 1996 and June 2012 were included. World Federation of Neurosurgical Societies grade, aneurysm site, size, and aneurysm neck size were recorded, along with clinical outcome assessed with the Glasgow Outcome Scale and radiographic occlusion assessed with the Raymond classification at 6 months and 2.5 years.RESULTS:A total of 295 patients with 300 MCA aneurysms were treated including 244 ruptured aneurysms (80.7%). The technical failure rate was 4.3% (13 patients). Complete occlusion or neck remnant was achieved in 264 (91.4%). Complications included rupture in 15 patients (5%), thromboembolism in 17 patients (5.7%), and early rebleeding in 3 patients (1%). Overall permanent procedural-related morbidity and mortality were seen in 12 patients (7.8%). Of the ruptured aneurysms, 189 (79.4%) had a favorable clinical outcome (Glasgow Outcome Scale score, 4–5). A total of 33 patients (13.6%) died. On initial angiographic follow-up, aneurysm remnant was seen in 18 aneurysms (8.1%). A total of 13 patients (4.3%) were re-treated.CONCLUSIONS:Our experience demonstrates that endovascular treatment of MCA aneurysms has an acceptable safety profile with low rates of technical failure and re-treatment. Therefore, coiling is acceptable as the primary treatment of MCA aneurysms.

The International Subarachnoid Aneurysm Trial (ISAT) demonstrated an absolute 6.9% reduction in the rate of death or dependency at 1 year for patients treated with endovascular coiling (EVC).¹ ISAT did not, however, address the specific issue of patients with MCA aneurysms, who represented only 303 (14.1%) of the 2143 enrolled patients. This has resulted in controversy as to the best mode of treatment of aneurysms at this location. Surgical clipping remains the standard treatment in many institutions. The anatomic location aids surgical access, and in some cases, surgery facilitates hematoma evacuation. There is also a perceived increased risk for EVC at this site because these aneurysms are often wide-neck and have branches arising from the neck.^2,3 Recently, several surgical series have been published that demonstrate excellent clinical results with low rates of morbidity and mortality.^4–7 Therefore, we analyzed the strategy at our institution where EVC is the first-line therapy for aneurysm treatment at any location and focused on the more controversial MCA aneurysms.     

Mechanical Recanalization Using Solitaire AB Device for Severe Thromboembolic Events in Endovascular Treatment of Intracranial Aneurysms

Introduction

Severe thromboembolism with complete occlusion of the proximal arteries during or after coil embolization can cause serious neurologic deficits. The study aimed to assess the effectiveness and safety of Solitaire AB device as a rescue therapy for severe thromboembolic complications in the endovascular treatment of intracranial aneurysms.

Materials and Methods

Between February 2013 and April 2016, 1047 intracranial aneurysms treated with endovascular procedures were retrospectively reviewed in our center. Severe thromboembolisms occurred in ten patients and were treated by Solitaire AB device including clot retriever and permanent stent deployment.

Results

The location of arterial occlusion was distal to the aneurysm rather than the coil/parent artery interface or in-stent area. Four patients had distal thromboembolic events before coil embolization, and six patients had it after coiling. The complete arterial recanalization (TICI 3) was achieved in all patients, and no cerebral hemorrhage was related to the procedure after the rescue therapy. Among these patients with the aforementioned neurovascular procedures, the mean Glasgow Outcome Scale (GOS) score was 4.5 (ranging 3–5) and eight cases had good outcome with a score of GOS 4–5 at discharge, while eight patients presented mRS ≤2 at 3-month follow-up.

Conclusions

These results demonstrate that mechanical recanalization using Solitaire AB device seems to be effective and safe as a rescue therapy for severe thromboembolic events during cerebral aneurysm embolization.

     

Endovascular Coiling of Wide-Neck and Wide-Neck Bifurcation Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:We present the results of a systematic review and meta-analysis examining outcomes of endovascular coiling of wide-neck and wide-neck bifurcation aneurysms with and without stent assistance. The aim of our study was to assess angiographic and clinical outcomes.MATERIALS AND METHODS:We performed a comprehensive literature search for all articles on the endovascular coiling of wide-neck and wide-neck bifurcation aneurysms. Studies meeting our inclusion criteria and abstracted data were selected by 2 independent reviewers. Primary outcomes were >6-month complete or near-complete angiographic occlusion, aneurysm recanalization, and aneurysm retreatment. Secondary outcomes included initial complete or near-complete occlusion, long-term good neurologic outcome, procedure-related morbidity, and procedure-related mortality. Data were analyzed by using random-effects meta-analysis.RESULTS:In total, 38 studies including 2446 patients with 2556 aneurysms were included. For all wide-neck aneurysms, immediate complete or near-complete occlusion rate was 57.4% (95% CI, 48.1%–66.8%). Follow-up near-complete occlusion rate was 74.5% (95% CI, 68.0%–81.0%). Recanalization and retreatment rates were 9.4% (95% CI, 7.1%–11.7%) and 5.8% (95% CI, 4.1%–7.5%), respectively. Long-term good neurologic outcome was 91.4% (95% CI, 88.5%–94.2%). For wide-neck bifurcation aneurysms, initial complete or near-complete occlusion rate was 60.0% (95% CI, 42.7%–77.3%), long-term complete or near-complete occlusion rate was 71.9% (95% CI, 52.6%–91.1%), and the recanalization and retreatment rates were 9.8% (95% CI, 7.1%–12.5%) and 5.2% (95% CI, 1.9%–8.4%), respectively.CONCLUSIONS:Our study of angiographic and clinical outcomes for patients with wide-neck aneurysms demonstrates that endovascular coiling with or without stent-assisted coiling is safe, with low rates of perioperative morbidity and mortality. Initial and long-term angiographic outcomes were generally satisfactory, but not ideal. These data provide some baseline comparisons against which emergent technologies can be assessed.

With the advent of stent-assisted and balloon-assisted coiling, wide-neck and wide-neck bifurcation intracranial aneurysms are increasingly treated with endovascular techniques to prevent hemorrhage or recurrent bleeding. Both stent-assisted and balloon-assisted coiling have been shown to be safe and effective in the treatment of these aneurysms by allowing for increased packing density and lower rates of parent artery occlusion compared with conventional coiling alone.^1–5 Even in the era of endoluminal and intrasaccular flow diverters, many wide-neck and wide-neck bifurcation aneurysms will continue to be treated with conventional coiling, particularly with stent assistance.^6–8We present the results of a systematic review and meta-analysis examining outcomes of endovascular coiling of wide-neck and wide-neck bifurcation aneurysms with and without stent-assisted coiling. The aim of our study was to assess both angiographic and clinical outcomes in order to provide overall data against which current and future emergent techniques can be compared.     

大脑后动脉动脉瘤的血管内治疗

目的 评价血管内方法治疗大脑后动脉动脉瘤的安全性和效果.方法 回顾性分析8例经血管内栓塞治疗的大脑后动脉动脉瘤的治疗效果、并发症以及随访情况.结果 8例患者均成功进行治疗,3例闭塞载瘤动脉,5例选择性栓塞动脉瘤,均无严重并发症.2例巨大动脉瘤患者闭塞载瘤动脉后头痛加重,2周后缓解.全部患者术后随访症状均消失,无动脉瘤破裂发生.结论 血管内方式治疗大脑后动脉动脉瘤,是安全有效的方法.     

腹主动脉瘤的腔内治疗

腹主动脉瘤（AAA）常发生于老年人，破裂是其最常见、最凶险的并发症，病死率可高达63%。传统开腹性手术是治疗AAA十分有效的手段，但对于高危患者其病死率显著增加。因此，发展一种微创方法治疗AAA对于降低病死率十分必要。经股动脉放置血管内支架-移植物是治疗AAA的一个重要里程碑，尤其对于那些高危患者。这一新技术作为外科修复的替代疗法已经得到广泛的应用。内支架-移植物植入后的常见并发症包括内漏、移植物移位或变形和移植物血栓形成，以内漏最常见且最重要。内漏是指移植物植入后仍有持续性血液进入动脉瘤囊，主要通过某些影像学技术证实，螺旋CT增强检查是检出内漏的首选方法。术后30天内发生的或早期内漏可通过一段时期观察，然后对待持续性内漏进行血管内介入治疗，30天后的晚发内漏应及时进行介入处理，无观察期。     

Endovascular Treatment of Ruptured Blister-Like Aneurysms: A Systematic Review and Meta-Analysis with Focus on Deconstructive versus Reconstructive and Flow-Diverter Treatments

BACKGROUND AND PURPOSE:Various endovascular techniques have been applied to treat blister-like aneurysms. We performed a systematic review to evaluate endovascular treatment for ruptured blister-like aneurysms.MATERIALS AND METHODS:We performed a comprehensive literature search and subgroup analyses to compare deconstructive versus reconstructive techniques and flow diversion versus other reconstructive options.RESULTS:Thirty-one studies with 265 procedures for ruptured blister-like aneurysms were included. Endovascular treatment was associated with a 72.8% (95% CI, 64.2%–81.5%) mid- to long-term occlusion rate and a 19.3% (95% CI, 13.6%–25.1%) retreatment rate. Mid- to long-term neurologic outcome was good in 76.2% (95% CI, 68.9%–8.4%) of patients. Two hundred forty procedures (90.6%) were reconstructive techniques (coiling, stent-assisted coiling, overlapped stent placement, flow diversion) and 25 treatments (9.4%) were deconstructive. Deconstructive techniques had higher rates of initial complete occlusion than reconstructive techniques (77.3% versus 33.0%, P = .0003) but a higher risk for perioperative stroke (29.1% versus 5.0%, P = .04). There was no difference in good mid- to long-term neurologic outcome between groups, with 76.2% for the reconstructive group versus 79.9% for the deconstructive group (P = .30). Of 240 reconstructive procedures, 62 (25.8%) involved flow-diverter stents, with higher rates of mid- to long-term complete occlusion than other reconstructive techniques (90.8% versus 67.9%, P = .03) and a lower rate of retreatment (6.6% versus 30.7%, P < .0001).CONCLUSIONS:Endovascular treatment of ruptured blister-like aneurysms is associated with high rates of complete occlusion and good mid- to long-term neurologic outcomes in most patients. Deconstructive techniques are associated with higher occlusion rates but a higher risk of perioperative ischemic stroke. In the reconstructive group, flow diversion carries a higher level of complete occlusion and similar clinical outcomes.

Blister-like aneurysms (BLAs) are intracranial arterial lesions originating at nonbranching sites of the dorsal supraclinoid internal carotid artery and basilar artery. BLAs account for 0.3%–1% of intracranial aneurysms and 0.9%–6.5% of ruptured aneurysms.^1–6 They are attributed to subadventitial dissections resulting in a focal wall defect with absence of internal elastic lamina and media, leading, in most cases, to acute subarachnoid hemorrhage. The arterial gap is only covered with adventitia and thin fibrinous tissue.^4,7–10Ruptured BLAs have a high mortality rate. Furthermore, treatment of these lesions is technically difficult because they often lack a defined neck and the aneurysm sac has a very thin wall.^4,11–13 Thus, ruptured BLAs are associated with high rates of spontaneous or treatment-induced rebleed and death, regardless of treatment type.^2,4,13,14Many surgical techniques such as wrapping or trapping with bypass have been described for the treatment of these lesions. However, such techniques are often associated with high perioperative morbidity and mortality rates.^{8,10,11,13,15–20} Because of these results, endovascular techniques, both reconstructive and deconstructive, have emerged as the treatment of choice due to perceived lower rates of treatment-related morbidity and higher efficacy.^{2–4,12,21–25} However, because of the rarity of these lesions, most series on endovascular treatment of BLAs are small retrospective single-center case series. Thus, the efficacy and safety of endovascular treatment of these lesions have not been well-established.⁴ In addition, little is known regarding whether reconstructive techniques with parent artery preservation are associated with similar rates of angiographic occlusion and improved clinical outcomes compared with deconstructive parent artery sacrifice.¹³ Therefore, we performed a systematic review of the literature examining the overall efficacy of endovascular treatments for ruptured BLAs and comparing outcomes of reconstructive techniques such as stent placement, flow diversion, and stent-assisted coiling with deconstructive techniques such as parent artery occlusion and trapping. We also performed a subgroup analysis comparing the safety and efficacy of flow-diverter treatment with other reconstructive techniques.