Platelet aggregation rate serves as a significant predictive indicator for thromboembolic events in the context of stent-assisted embolization for unruptured arterial aneurysms

Background

Perioperative cerebrovascular thromboembolic events are serious complications of stent-assisted embolization (SAE) for unruptured intracranial aneurysms (UIAs). To date, there have been no definitive clinical trial results to effectively predict and prevent the occurrence of this complication. This study aims to elucidate the correlation between platelet aggregation rate (PAR) and thromboembolic events (TEs), with the goal of predicting the occurrence of cerebrovascular TEs in these patients.

Methods

In this retrospective, single-center cohort study, we included 704 cases of unruptured intracranial aneurysms treated with stent-assisted intervention from 2016 to 2020. Cerebrovascular TEs were defined as cerebral ischemic events occurring within 7 days before or after the interventional procedure. Light Transmission Aggregometry (LTA) was used to detect PAR in patients. Clinical data, including patients' demographic information and perioperative PAR, were collected. Multivariate analysis was conducted to examine the correlation between these factors and the occurrence of TEs. Additionally, Lasso regression was employed to select clinical indicators associated with perioperative TEs. Receiver Operating Characteristic (ROC) curves were generated for prognostic indicators such as PAR, with the optimal cutoff value determined. A nomogram was then simulated, and predictive accuracy of the model was evaluated using Decision Curve Analysis (DCA).

Results

A total of 562 patients were included in the final analysis. Significant differences were observed in the incidence of thrombosis between the control group and the experimental group (9.38% vs. 4.96%). The ROC curve of platelet aggregation index, highly correlated with prognosis and derived from Lasso regression, identified the optimal cutoff value for the maximum preoperative PAR as 19.81. A nomogram was constructed based on selected clinical baseline data, and its calibration was assessed using data from the prediction group. The net benefit of the experimental group model's DCA curve was significantly improved.

Conclusion

For patients undergoing SAE for UIAs, utilizing PAR and other indicators as reference standards for treatment results in better prognosis compared to empirical treatment based on guidelines. Guiding antiplatelet therapy using PAR and other indicators is both meaningful and beneficial to clinical practice.

Risk Factors, Antithrombotic Management, and Long-Term Outcomes of Patients Undergoing Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND

 Patients receiving endovascular treatment for unruptured intracranial aneurysms (UIAs) face varying risks and benefits with antithrombotic management. This study aimed to evaluate the perioperative and long-term effects of antithrombotic strategies, identify the populations that would benefit, and explore the predictive factors affecting the long-term outcomes.

METHODS

 UIA patients undergoing endovascular treatment including stent-assisted coiling or flow diversion between June 2019 and June 2022 were enrolled. We compared perioperative and long-term complications between tirofiban and dual antiplatelet therapy groups. Optimal candidates for each antithrombotic treatment were identified using multivariate logistic regression. Nomograms were developed to determine the significant predictors for thromboembolic complications during follow-up.

RESULTS

 Among 181 propensity-score matched pairs, the tirofiban group showed a trend toward a lower rate of thromboembolic complications than the DAPT group without elevating major bleeding risk in either period. Homocysteine (Hcy) level ≥10 μmol/L was a significant independent factor associated with thromboembolic complication in both periods. Subgroup analysis highlighted that in patients with high Hcy levels, tirofiban and sustained antiplatelet treatment for ≥12 months were protective factors, while a history of stroke was an independent risk factor for thromboembolic events in follow-up. Four variables were selected to construct a prognostic nomogram, history of hypertension, prior stroke, Hcy level, and the duration of antiplatelet therapy.

CONCLUSION

 Perioperative low-dose tirofiban and extended antiplatelet therapy demonstrated a favorable trend in long-term outcomes for UIA patients with preoperative Hcy levels ≥10 μmol/L undergoing endovascular treatment. The prognostic model offers reliable risk prediction and guides antithrombotic strategy decisions.

Management strategies of unanticipated intracranial stenosis during mechanical thrombectomy for acute stroke: A survey of academic neurointerventionalists

BACKGROUND

The optimal approach to the management of intracranial atherosclerotic disease (ICAD) at the time of mechanical thrombectomy (MT) for large vessel occlusion (LVO) remains controversial. The goal of this study is to characterize current practices concerning this challenging clinical situation in a survey of practicing neurointerventionalists.

METHODS

An electronic questionnaire was sent to a cross-section of North American academic neurointerventionalists using publicly available contact information and departmental websites. Prior to analysis, responses were anonymized and categorized by region.

RESULTS

A total of 136/360 responses were recorded from the U.S. and Canada. The mean number of years of practicing as a neurointerventionalist among the respondents was 10.5 (± 6.2 years). ICAD was perceived as a causative factor during MT for LVO in 5-10% of thrombectomy cases. The most common first-line treatment approach for significant ICAD, assuming a TICI 2b or better reperfusion, was medical therapy (77.9% of respondents), followed by angioplasty + stent placement (8.8% of respondents). There were no significant differences in the first line treatment of ICAD in LVO between geographical regions (p = 0.815).

CONCLUSION

The approach to underlying ICAD in LVO varies widely; however, the majority of neurointerventionalists prefer medical therapy with DAPT as a first-line treatment approach. The current survey highlights the need for studies that better define the optimal timing and modality of treatment, along with an evidence-based framework for balancing the risks associated with these treatment approaches.

Intra-arterial injection of mesenchymal stem cells to accelerate neointima formation after endovascular stenting in a rabbit model

OBJECTIVE

Delayed neointima formation over a neurovascular stent is associated with thrombotic complications that can lead to stroke. The purpose of this study was to evaluate whether an intra-arterial injection of mesenchymal stem cells (MSCs) after stent placement leads to improved neointima and reduced thrombus formation over the device.

METHODS

Solitaire stents were placed into the aortas of rabbits that were divided into MSC and control groups. The MSC group received an intra-arterial injection of MSCs through the same microcatheter used for stent deployment. Optical coherence tomography (OCT) was used to evaluate and compare neointima and thrombus formation in a blinded fashion. Explanted specimens were also imaged with scanning electron microscopy (SEM) and evaluated by observers blinded to group allocation using an endothelialization scoring system.

RESULTS

The 3-day MSC group was similar to the 7-day controls in terms of stent strut coverage ratio and maximum neointimal thickness, but these values were significantly higher than the 3-day control group based on a hierarchical mixed-effects linear regression analysis. SEM revealed a significantly higher endothelialization score for the MSC group compared with controls at the same time point. There was no difference in thrombus formation between any of the groups.

CONCLUSIONS

The intra-arterial injection of MSCs after endovascular stenting accelerated early neointima formation but had no effect on thrombus formation in this study. Larger studies are required to verify these findings and determine the durability and mechanism of this effect.

Imaging Intracranial Aneurysms in the Endovascular Era: Surveillance and Posttreatment Follow-up

While most intracranial aneurysms (IAs) remain asymptomatic over a patient's lifetime, those that rupture can cause devastating outcomes. The increased usage and quality of neuroimaging has increased detection of unruptured IAs and driven an increase in surveillance and treatment of these lesions. Standard practice is to treat incidentally discovered unruptured IAs that confer high rupture risk as well as ruptured IAs to prevent rehemorrhage. IAs are increasingly treated with coil embolization instead of microsurgical clipping; more recently, flow diversion and intrasaccular flow disruption have further expanded the versatility and utility of endovascular IA treatment. Imaging is increasingly used for posttreatment IA follow-up in the endovascular era. While cerebral angiography remains the standard for IA characterization and treatment planning, advances in CT and CT angiography and MR angiography have improved the diagnostic accuracy of noninvasive imaging for initial diagnosis and surveillance. IA features including size, dome-to-neck ratio, location, and orientation allow rupture risk stratification and determination of optimal treatment strategy and timing. The radiologist should be familiar with the imaging appearance of common IA treatment devices and the expected imaging findings following treatment. In distinction to clipping and coil embolization, flow diversion and intrasaccular flow disruption induce progressive aneurysm obliteration over months to years. Careful assessment of the device; the treated IA; adjacent brain, bone, meninges; and involved extracranial and intracranial vasculature is crucial at posttreatment follow-up imaging to confirm aneurysm obliteration and identify short-term and long-term posttreatment complications. An invited commentary by Chatterjee is available online. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ^©RSNA, 2022.

Longitudinal Cost Profiles of Pipeline Embolization Device Versus Stent-Assisted Coiling in Propensity-Matched Unruptured Small Anterior Circulation Aneurysms

BACKGROUND

The cost profiles of stent-assisted coiling (SAC) vs Pipeline embolization device (PED) in small unruptured anterior circulation aneurysms have not been studied.

OBJECTIVE

To compare the 2 modalities cost profiles in a propensity-matched cohort controlling for potential technical complexity confounders including size and location.

METHODS

Patients treated with either SAC or PED at our institution were identified. Following propensity-score algorithm, 46 patients, 23 in each group were matched. The procedural and follow-up costs in each group were analyzed and compared.

RESULTS

Median maximal aneurysm size in the SAC and PED cohort were 5.3 vs 5.1 mm, respectively. Costs of access guide materials were significantly higher in the SAC group (P < .01). The average implant cost was not significantly different between the SAC and PED cohorts (${\$}$13973.2 ± ${\$}$2886.2 vs ${\$}$14,760.7 ± ${\$}$3782.1, respectively; P = .43). Similarly, total procedural costs were not different (${\$}$18341.5 ± 4104 vs ${\$}$17484.3 ± 2914.1, respectively, P = .42). Although there were significantly more total follow-ups (P = .02) and longer follow-up duration (P = .01) in SAC cohort, no significant difference in follow-up costs between the 2 groups was identified (${\$}$20557 ± ${\$}$9247 vs ${\$}$18958 ± ${\$}$9171.9, P = .56). Overall cost was similar between the SAC (${\$}$38898.9 ± ${\$}$9645.5) and PED groups (${\$}$36442.4 ± ${\$}$9076) (P = .38).

CONCLUSION

In small unruptured anterior circulation aneurysms (excluding anterior communicating artery aneurysms) matched for technical complexity confounders, SAC and PED offer an overall equivalent economic cost profile. Postprocedural noninvasive imaging was more frequent in the SAC group. However, follow-up costs and total costs were not significantly different.

Y-stent assisted coiling of ruptured wide neck intracranial aneurysm in the acute phase

BACKGROUND

The objective of the present study is to analyze the outcomes of patients with subarachnoid hemorrhage (SAH) in the acute phase after treatment with Y-stent-assisted coiling (YSAC) embolization.

METHODS

This retrospective study assessed of 30 patients with acutely ruptured wide-neck aneurysms following YSAC treatment between April 2013 and October 2019. The demographic data, aneurysm occlusion grade, procedural and periprocedural complications, and clinical outcomes were assessed.

RESULTS

The procedure was completed in 30 cases (90.1%) and technical failure occurred in 3 cases (9.1%). Immediate control angiography revealed that total occlusion Raymond-Ray Class 1 (RR1) was achieved in 21 (70%), neck filling (RR2) in eight (26.6%) and sac filling (RR1) in one (3.3%) aneurysm. Upon angiographic follow-up, RR1 occlusion was observed in 15 (71.4%) patients, RR2 in three (14.3%) patients and RR3 in three (14.3%) patients. In-stent thrombus developed in five (16.6%) patients; procedural ischemic events were observed in four (13.3%) patients; and two (6.6%) patients were symptomatic. A periprocedural asymptomatic intracranial hemorrhage was detected in two patients. At discharge, 17 (56.6%) patients were in good clinical condition, six (20%) were in a severe disability condition, and seven (23.3%) patients had died. At the final follow-up visit (mean: 18.9 months), 16 (76,2%) of 21 patients were in a good clinical condition and five (23.8%) had severe disabilities.

CONCLUSIONS

Y-stent assisted coiling in might be a feasible and promising option for treatment in acute phase in selected wide-necked ruptured intracranial aneurysms.

The Prophylactic Use of Tirofiban versus Oral Antiplatelet Medications in Stent-Assisted Coiling of Intracranial Aneurysms: A Meta-analysis

BACKGROUND

The protocol for optimal antiplatelet therapy to prevent thromboembolic and hemorrhagic complications in patients with cerebral aneurysms using an endovascular approach is not clear.

PURPOSE

Our study analyzed the safety and efficacy of prophylactic tirofiban administration compared with oral antiplatelet drug therapy.

DATA SOURCES

We used the PubMed, EMBASE, MEDLINE, and Cochrane library data bases.

STUDY SELECTION

Our study consisted of all case series with >5 patients that reported treatment-related outcomes of patients undergoing endovascular procedures pretreated with tirofiban or oral antiplatelet drug therapy.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of complications, perioperative mortality, and good clinical outcomes.

DATA SYNTHESIS

Fifteen studies with 1981 patients were registered. Thromboembolic complications were significantly lower in the tirofiban group (3.6%; 95% CI, 1.9%-5.8%) compared with the dual-antiplatelet therapy group (8.5%, 95% CI, 4.5%-13%; P = .04). Pretreatment with tirofiban did not remarkably increase the rate of hemorrhagic complications (3.5%; 95% CI, 1.8%-5.6%) compared with dual-antiplatelet therapy (5.1%; 95% CI, 2.6%-8.5%; P = .371). There was a trend toward lower perioperative mortality with tirofiban (0.8%; 95% CI, 0.2%-1.6%) compared with dual-antiplatelet therapy (1.2%; 95% CI, 0.7%-2.0%; P = .412). There was no significant difference in the safety and efficacy between the tirofiban bolus plus drip and drip alone.

LIMITATIONS

The limitations are selection and publication biases.

CONCLUSIONS

Prophylactic therapy with tirofiban resulted in significantly lower rates of thromboembolic complications with no increase in hemorrhagic events or mortality than the prophylactic use of dual-antiplatelet therapy.

Open-cell stent-assisted coiling for the treatment of paraclinoid aneurysms: traditional endovascular treatment is still not out of date

PURPOSE

Before we enter the era of flow diverter stents (FDS), the standard stent-assisted coiling technique is a well-established treatment option for routine paraclinoid aneurysms. We assess the clinical safety and efficacy of stent-assisted coiling with open-cell stent in the treatment of paraclinoid aneurysms and evaluate the association between clinical factors and follow-up aneurysm occlusion.

METHODS

The clinical and radiographic data of 110 consecutive patients with 122 paraclinoid aneurysms treated with open-cell stent between April 2015 and April 2019 were analyzed retrospectively at our center. We assessed the immediate and progressive occlusion rates, complications, and clinical outcome. Multivariate analysis was performed to investigate the risk factors of angiographic incomplete occlusion.

RESULTS

Among 110 patients, stent-assisted coiling was successfully performed in all cases. Four (3.6%) thromboembolic events were reported during the procedure, which resulted in transient morbidity. Immediate angiography demonstrated complete occlusion in 64 (52.5%) aneurysms and no occlusion of ophthalmic artery. Angiographic follow-up at 6 months demonstrated an increase in the complete occlusion rate to 92.9%. No delayed in-stent stenosis was observed, and three aneurysms recurred. Clinical follow-up was completed in 102 patients (92.7%), and favorable outcomes were achieved in 101 (99%) patients at 6 months. Multivariate analysis showed that aneurysm size (p < 0.001) was associated with incomplete aneurysm occlusion at follow-up.

CONCLUSION

Stent-assisted coil embolization with open-cell stents is safe and effective for the treatment of paraclinoid aneurysms and provides progressive occlusion without significant in-stent stenosis events.

Failure of Flow Diverter Therapy: Predictors and Management Strategies

Flow diversion is a safe and effective treatment for many types of brain aneurysms. Even so, there remain some aneurysms that persist despite initial treatment. In studies with the longest follow-up (5 yr), at least 5% of aneurysms persist with this treatment modality. As the cumulative experience and clinical indications for flow diversion continue to expand, the anatomic and functional characteristics that are associated with aneurysm persistence are increasingly described. Identification of these factors preoperatively can help to guide initial treatment decisions, enhance monitoring protocols in the follow-up period, and establish best practices for re-treatment when necessary. Herein, we review published clinical series and provide examples to highlight variables implicated in aneurysm persistence after treatment with flow diversion.

Safety of stent-assisted coiling for the treatment of wide-necked ruptured aneurysm: A systematic literature review and meta-analysis of prevalence

BACKGROUND

Stent-assisted coil embolization of ruptured wide-necked aneurysms is a controversial treatment modality due to concerns on the peri-procedural safety of anti-platelet therapy in the setting of acute subarachnoid hemorrhage. Our aim was to systematically review the literature on stent-assisted coil embolization of acutely ruptured wide-neck aneurysms to calculate the pooled prevalence of clinical outcome, thromboembolic and hemorrhagic complication rates and overall mortality.

METHODS

We searched PubMed and Google Scholar for articles published between 2009 and 2019 and stratified selected articles based on risk of publication bias. Data on thromboembolic and hemorrhagic complications, clinical outcomes and mortality rates were analyzed using quality-effects model and double arcsine transformation.

RESULTS

24 articles were included featuring a total of 1582 patients. Thromboembolic and hemorrhagic complication rates were witnessed in 9.1% [95% CI: 6.0% - 12.7%; I² = 72.8%] and 8.7% [95% CI: 5.4 - 12.6%; I² = 77.2%] of patients, respectively. 245 patients received external ventricular drains, of which 33 (13.5%) had EVD-related hemorrhages. Total complication rate was 20.8% [95% CI: 14.2 - 28.1%; I² = 87.0%]. 57% of aneurysms were completely occluded and a favorable clinical outcome was reported in 74.7% [95% CI: 66.4 - 82.2%; I² = 86.0] of patients. Overall mortality rate came at 7.8% [95% CI: 4.8 - 11.6%; I² = 76.9%].

CONCLUSION

Stent-assisted coiling of ruptured intracranial aneurysm is a technically feasible procedure with controlled thromboembolic complication rate but may be associated with higher hemorrhagic and total complication rates compared to coiling alone. While stent-assisted coiling of ruptured wide-necked aneurysm seems to yield a lower rate of favorable clinical outcome, overall mortality is comparable to that of endovascular coiling alone.

Stent and flow diverter assisted treatment of acutely ruptured brain aneurysms

OBJECTIVE

We present our experience with stent techniques in the management of acutely ruptured aneurysms, focusing on aneurysm occlusion rates, intraprocedural complications, and late outcomes.

METHODS

We retrospectively reviewed the clinical records of patients treated by stent techniques during the early acute phase of aneurysmal rupture, from June 2011 to June 2016. Patients who underwent stenting for the management of unruptured aneurysms, or in a delayed fashion for a ruptured lesion, were excluded.

RESULTS

47 patients met inclusion criteria, including 46 with subarachnoid hemorrhage (SAH). There were 27 men and 20 women, mean age 38 years (range 23-73). They harbored 71 aneurysms, including 56 treated in the acute phase. Aneurysmal dome and neck width averaged 4.7 mm (range 1.7-12.1) and 3.2 mm (range 1.5-7.1), respectively. Single stent techniques were used in 39 patients and dual stent techniques in 17. External ventricular drains (EVDs) were placed before embolization in 35 patients (92%) and after in 3. Intraprocedure thromboembolic complications due to a hyporesponse to antiplatlets in 4 patients (8.5%) were successfully managed with intra-arterial antiplatelet agents. In 45 surviving patients (96%), there was complete aneurysm occlusion at the 9-12 month follow-up in 26/29 aneurysms treated by stent-assisted coiling (90%), in 2/3 aneurysms treated by flow diverter-assisted coiling (66%), and in 19/22 aneurysms treated by flow diverter alone (86%); 42/45 patients (93%) presented with a modified Rankin Scale score of 0-2.

CONCLUSION

Stenting techniques in ruptured aneurysms can be performed with good technical success; however, procedural thromboembolic complications related to the antiplatelet strategy merit investigation. EVD placement before stenting must be considered.

Evaluation of ischemic lesion prevalence after endovascular treatment of intracranial aneurysms, as documented by 3-T diffusion-weighted imaging: a 2-year, single-center cohort study

OBJECTIVE

Even though published data exist concerning the prevalence of ischemic lesions detected by diffusion-weighted imaging (DWI) following endovascular treatment of intracranial aneurysms, a single-center cross-evaluation of the different endovascular techniques has been lacking. The authors sought to prospectively evaluate the prevalence and clinical significance of ischemic lesions occurring after endovascular treatment of intracranial aneurysms and to compare the safety and effectiveness of a broad spectrum of currently accepted endovascular techniques in a single-center setting.

METHODS

This was a prospective cohort study involving consecutive patients treated for intracranial aneurysms exclusively by endovascular means, excluding treatments in the acute rupture phase, in a center featuring an endovascular-only treatment policy for intracranial aneurysms. All patients underwent MRI, including a 3-directional DWI sequence, before treatment, 24 hours postprocedure, and 6 months following endovascular embolization. Selective angiography was performed at 6 months’ follow-up.

RESULTS

From January 2012 through December 2013, 164 aneurysms were treated in 128 consecutive patients. Endovascular techniques included coiling (14.6%), balloon-assisted coiling (20.1%), stent-assisted coiling (3.7%), low-profile stent-assisted coiling, flow diversion (38.4%), and very complex treatments (6.1%) involving 2 stents in Y or T configurations. On postprocedure MRI, the rates of occurrence of new DWI-positive lesions were 64.3% for coiling, 54.5% for remodeling, 61.1% for stent-assisted coiling, 53.7% for flow-diverting stents, and 75% for very complex treatments (p = 0.4962). The 6-month procedure-related morbidity and mortality rates were 6.25% and 0%, respectively. At 6 months’ follow-up, 93% of the patients had modified Rankin Scale (mRS) scores of 0–2. Very complex treatments offered a higher complete occlusion rate (100%) than all other techniques (66.7%–88.9%). Age and length of procedure were independent factors for DWI lesion occurrence. The diameter of DWI lesions on 24-hour postprocedure MRI was positively correlated with mRS score at discharge. Among the DWI-positive lesions measuring less than 2 mm in diameter on the 24-hour MRI, 44.12% had regressed at 6 months.

CONCLUSIONS

Procedure-related DWI lesions are far more often encountered in silent forms than they are clinically evident. They do not seem to be significantly correlated with procedure-related complications, nor do they seem to impair clinical outcome, regardless of the endovascular technique. Small lesions (< 2 mm in diameter) may regress within 6 months. The use of the most adapted technique, in terms of aneurysm configuration, results in significant total occlusion rates, with acceptable safety.

Antiplatelet Premedication-Free Stent-Assisted Coil Embolization in Acutely Ruptured Aneurysms

OBJECTIVE

Stent-assisted coil embolization (SAC) is one of the treatment options for patients with intracranial aneurysms. The purpose of this study was to assess clinical outcomes of patients who underwent coil embolization for acutely ruptured aneurysms without antiplatelet premedication.

METHODS

A total of 449 patients with acutely ruptured aneurysms underwent endovascular treatment without antiplatelet premedication between April 2006 and October 2015. Among them, 55 patients underwent SAC (SAC group) and 394 underwent coiling without stent assistance (non-SAC group). Periprocedural complications and clinical outcomes at postictal 6 months were compared between the 2 groups.

RESULTS

The rate of hemorrhagic complications showed no significant difference (SAC group vs. non-SAC group, 9.1% vs. 4.8%). Although procedural thromboembolism occurred more frequently in the SAC group (25.5% vs. 12.4%; P = 0.01), poor clinical outcomes (modified Rankin scale score ≥3) were comparable (30.9% vs. 22.1%). In the multivariate analysis, Hunt-Hess grade (odds ratio [OR] = 4.22; P < 0.001), hemorrhagic complications (OR = 4.01; P = 0.018), and age (OR = 1.04, P = 0.001) were independent predictors of poor clinical outcomes, but stent-assisted coil embolization and procedural thromboembolism were not.

CONCLUSIONS

Although procedure-related thromboembolism occurred more frequently, comparable treatment outcomes could be achieved with antiplatelet premedication-free SAC in patients with acutely ruptured aneurysms. The use of stents and thromboembolic complications were not significant risk factors for poor clinical outcome.

Intravenous administration of tirofiban versus loading dose of oral clopidogrel for preventing thromboembolism in stent-assisted coiling of intracranial aneurysms

Background Thromboembolic complications after stenting of intracranial aneurysms may be affected by antiplatelet administration. Aims This retrospective study aimed to assess the safety of intravenous tirofiban versus loading dose of oral clopidogrel for preventing thromboembolism in stent-assisted coiling of intracranial aneurysms. Methods From January 2006 to December 2013, 281 patients with cerebral aneurysms were treated with stent-coiling using two antiplatelet strategies in comparison: the initial strategy (a loading dose of ≥300 mg clopidogrel followed by dual antiplatelet, clopidogrel group) and the modified strategy (intravenous administration of tirofiban 8 µg/kg over 3 min followed by a maintenance dose of 0.1 µg/kg/min for 24 h, tirofiban group). The end points were rates of perioperative thromboembolic events and intracranial hemorrhages. Results Thromboembolic events were observed more often in the clopidogrel group (13/120 aneurysms, 10.83%) than the tirofiban group (6/178 aneurysms, 3.37%; P = 0.010), with no increase in the rate of intracranial hemorrhages ( P = 0.164). In the ruptured subgroups, thromboembolic events were significantly fewer in the tirofiban subgroup (5/128, 3.91%) compared with the clopidogrel subgroup (7/53, 13.21%; P = 0.043) with no increase in the rate of hemorrhage ( P = 0.360). Conclusions Intravenous administration of tirofiban is safe in intracranial aneurysms treated with stent-assisted coiling.

Comparison of Stent-Assisted Coiling and Balloon-Assisted Coiling in the Treatment of Ruptured Wide-Necked Intracranial Aneurysms in the Acute Period

OBJECTIVE

The purpose of this study was to compare the efficacy, stability, and safety of stent-assisted coiling (SAC) and balloon-assisted coiling (BAC) in the treatment of ruptured wide-necked aneurysms in the acute period.

METHODS

Consecutive patients including 65 cases treated with SAC and 32 with BAC were reviewed at the authors' institution between November 2011 and December 2014. The efficacy of these 2 approaches and the incidence of periprocedural complications were retrospectively evaluated.

RESULTS

Morphologic analysis showed a lower fundus/neck ratio (1.2 vs. 1.6) in the aneurysms treated with SAC versus BAC (P < 0.001). The mean neck width of aneurysms was 4.0 mm in the patients treated with SAC versus 3.4 mm in those treated with BAC (P < 0.04). Coil protrusion into the parent vessels during embolization was an independent risk factor for cerebral ischemic events (odds ratio [OR], 4.08; 95% confidence interval [CI], 1.03-16.2). Neck width (OR, 0.65; 95% CI, 0.44-0.97) and aneurysm perforation during procedure (OR, 6.24; 95% CI, 1.21-32.3) were independent predictors of complete occlusion (Raymond 1) by immediate postembolization angiography. There was no statistical difference between the 2 techniques regarding the rate of aneurysm occlusion at the end of procedure, periprocedural complications, and favorable outcome at discharge and follow-up.

CONCLUSIONS

These findings suggested that SAC was more appropriate than BAC for ruptured wide-necked aneurysms with lower fundus/neck ratio or wider neck size. However, periprocedural complications, occlusion rates, and favorable outcomes did not differ between the 2 techniques.

Balloon remodeling may improve angiographic results of stent-assisted coiling of unruptured intracranial aneurysms

BACKGROUND

Endovascular treatment of wide-necked and complex aneurysms may require stent-assisted coiling, either as primary stenting or combined with the balloon remodeling technique (BRT).

OBJECTIVE

To compare the angiographic results and clinical outcomes of both strategies in the Safety and Efficacy of Neuroform for Treatment of intracranial Aneurysms (SENAT) registry.

METHODS

SENAT was a prospective, multicenter registry that allowed BRT in conjunction with stenting and coiling with bare platinum coils. Clinical and angiographic outcomes of 97 patients with unruptured aneurysms treated with stenting, 51 after BRT (BRT+) and 46 without balloon assistance (BRT-), were retrieved from the SENAT database. Technical, clinical, and angiographic outcomes were compared between the 2 groups.

RESULTS

Periprocedural morbimortality and midterm clinical outcomes were not different between groups. Residual aneurysms were observed in 7.8% of BRT+ and in 21.7% of BRT- (P = .08) at the end of the stenting procedure. Four retreatments were performed during the follow-up period (2 BRT+, 2 BRT-). Twelve- to 18-month anatomic results showed a significant difference between groups, with a residual aneurysm being observed in 6.1% of BRT+ as compared to 22.7% of BRT- patients (P = .03).

CONCLUSION

Primary BRT followed by stent-assisted coiling may be associated with fewer residual aneurysms at 12 to 18 months as compared to stent-assisted coiling alone.

The combined treatment of stenting and surgery in a giant unruptured aneurysm of the middle cerebral artery

BACKGROUND

This case study reports on a combined therapy of stenting and surgery for a giant unruptured middle cerebral artery (MCA) aneurysm with the aim of preserving the patency of the vessel during surgery.

CASE DESCRIPTION

A 51-year-old male presented with a sudden onset of moderate left hemiparesis and dysarthria. Neuro-radiological evaluations showed a giant right unruptured MCA aneurysm without subarachnoid hemorrhage (SAH). The cerebral angiography confirmed the presence of such an aneurysm producing compression of both M2 branches with consequent slowing of the blood flow. Two weeks later, the patient underwent the positioning of an Enterprise stent and inside this, a flow diverter Silk stent. They were placed across the aneurysm and in one of the two M2 branches with the aim of protecting them during surgical manipulation. The patient went immediately to surgery, where the aneurysm was resected and both M2 branches decompressed.

CONCLUSION

The combined placement of the stents allowed safe and successful surgical dissection of the M2 branches and clipping of the aneurysm without interrupting the blood flow.

Concurrent use of the Pipeline Embolization Device and coils for intracranial aneurysms: technique, safety, and efficacy

OBJECT

The use of the Pipeline Embolization Device (PED) as a sole endovascular modality has been described for the treatment of brain aneurysms. The benefit of using coils concurrently with a limited number of PEDs is not well documented. The authors describe their experience with this technique as well as their midterm clinical and angiographic results.

METHODS

This is a retrospective review of patients treated between 2011 and 2014. The authors placed a minimal number of PEDs with the addition of coils using a "jailed" microcatheter technique. A partially dense coil mass was obtained. Immediate and midterm clinical and angiographic results are reviewed.

RESULTS

The authors treated 27 patients harboring 28 aneurysms using this technique. The mean aneurysm size was 11.9 mm, and the mean neck size was 5.4 mm. A mean of 1.48 PEDs were placed per patient, and a mean of 1.33 PEDs per aneurysm were placed. The Raymond score immediately after PED placement was 2 or 3 in 82.1% of the patients. There were no intraprocedural or postprocedural complications. All PEDs were successfully deployed. No clinical or technical adverse effects related to the coil mass were observed. There were no clinical or radiographic signs of ischemia in this group. At follow-up imaging, complete aneurysm occlusion was demonstrated on the first MR angiogram (3-5 months) in all patients who reached this milestone. Follow-up digital subtraction angiography (5-13 months) confirmed complete occlusion in all patients who reached this milestone. All patients maintained their baseline clinical status.

CONCLUSIONS

The deployment of PEDs with concurrent partially dense coiling is safe and efficacious. This technique achieved early complete occlusion and endovascular reconstruction of the parent vessel, without inducing mass effect. Favorable midterm clinical results were observed in all patients.

Ocular thrombosis after stent-assisted coiling of a c7 (paraclinoid) internal carotid artery aneurysm. A report of two cases and literature review

Stent-assisted coiling of paraclinoid aneurysms is widely performed in neurointerventional surgery. The most common adverse event related to this procedure is cerebral thromboembolism. However, reports on ocular thromboembolism are scarce. We report our experience with two patients who developed ocular thromboembolism following Enterprise stent-assisted coiling of paraclinoid aneurysms. We then review the available literature for the possible pathomechanism of ocular thrombosis. Ocular thromboembolism may be a risk of stent-assisted coiling when the stent traverses the orifice of the ophthalmic artery or the stent is placed in the C3 internal carotid artery. Further study is needed to clarify how to avoid this disabling complication.

Stent-assisted coil embolization of ruptured wide-necked aneurysms in the acute period: incidence of and risk factors for periprocedural complications

OBJECT.: The purpose of this study was to report the authors' experiences in stent-assisted coil embolization (SAC) of ruptured wide-necked aneurysms in the acute period and to evaluate the incidence of and risk factors for periprocedural complications.

METHODS

A total of 72 patients were recruited for this study between March 2007 and June 2012. All patients met the following criteria: 1) the presence of ruptured intracranial wide-necked saccular aneurysms, and 2) the patient underwent SAC for treatment of those aneurysms within 72 hours of rupture. All of the patients with clinically poor grades or acute hydrocephalus underwent external ventricular drainage (EVD) before SAC. The incidence of and risk factors for periprocedural complications were retrospectively evaluated.

RESULTS

Of the 72 patients included in this study, periprocedural complications occurred in 14 (19.4%), including asymptomatic complications in 4 (5.6%) and symptomatic complications in 10 (13.9%); there were symptomatic thromboembolic complications in 5 patients (6.9%), and symptomatic hemorrhagic complications in 5 (6.9%). The authors observed no subacute or delayed thromboembolic complications during the follow-up period of 18.8 months. Use of EVD (OR 1.413, 95% CI 0.088-2.173; p = 0.046) was the only independent risk factor for periprocedural complications on multivariate logistic regression analysis.

CONCLUSIONS

The periprocedural complication rate during SAC was 19.4% among 72 patients. Because of the high complication rate, microsurgical clipping or endovascular treatment with another technique (multiple-microcatheter or balloon-assisted technique) may be a more appropriate option for first-line treatment than SAC, especially in patients requiring EVD.

Advances in Endovascular Approaches to Cerebral Aneurysms

Recent advancements in all phases of endovascular aneurysm treatment, including medical therapy, diagnostics, devices, and implants, abound. Advancements in endovascular technologies and techniques have enabled treatment of a wide variety of intracranial aneurysms. In this article, technical advances in endovascular treatment of cerebral aneurysms are discussed, with an effort to incorporate a clinically relevant perspective. Advancements in diagnostic tools, medical therapy, and implants are reviewed and discussed.

Extending the Indications of Flow Diversion to Small, Unruptured, Saccular Aneurysms of the Anterior Circulation

Background and Purpose—

Flow diverters are currently indicated for treatment of large and complex intracranial aneurysms. The purpose of this study was to determine whether the indications of flow diversion can be safely extended to unruptured, small, saccular aneurysms (<10 mm) of the anterior circulation.

Methods—

Forty patients treated with the pipeline embolization device (PED) were matched in a 1:4 fashion with 160 patients treated with stent-assisted coiling based on patient age, sex, aneurysm location, and aneurysm size. Procedural complications, angiographic results, and clinical outcomes were analyzed and compared.

Results—

The rate of periprocedural complications was 5% in the PED group and 3% in the stent-coil group ( P =0.7). In multivariable analysis, increasing age was the only predictor of complications. At follow-up, a higher proportion of aneurysms treated with PED (80%) achieved complete obliteration compared with stent-coiled aneurysms (70%) but the difference did not reach statistical significance ( P =0.2). In multivariable analysis, increasing aneurysm size and aneurysm location were predictors of nonocclusion. The rate of favorable outcome (modified Rankin Scale, 0–2 and modified Rankin Scale, 0–1) was similar in the PED group and the coil group.

Conclusions—

The PED was associated with similar periprocedural risks, clinical outcomes, and angiographic results compared with stent-assisted coiling. These findings suggest that the indications of PED can be safely extended to small intracranial aneurysms that are amenable to conventional endovascular techniques. Larger studies with long-term follow-up are necessary to determine the optimal treatment that leads to the highest rate of obliteration and best clinical outcomes.

Endovascular treatment of ruptured intracranial aneurysms

Aneurysmal subarachnoid hemorrhage (SAH) is a catastrophic neurologic event. Early triage of patients with SAH should include cardiopulmonary stabilization, neurologic assessment, and imaging. Conventional angiography with 3-dimensional rendering is necessary to accurately assess aneurysm morphology and location, so that treatment can be planned appropriately. Current evidence suggests that coil embolization can be beneficial for aneurysms amenable to endovascular treatment. The use of remodeling techniques has expanded the range of aneurysms treatable by endovascular means. Balloon remodeling can be a powerful technique for treating ruptured aneurysms with unfavorable morphology. However, stent-assisted technique is associated with significantly higher complication rates in ruptured aneurysms and requires dual antiplatelet agents, and should therefore be considered with great caution for ruptured aneurysms. Complications of ruptured aneurysm embolization include aneurysm perforation, which should be addressed with immediate occlusion of the aneurysm, and thromboembolism, which can be managed most effectively with glycoprotein IIb/IIIa inhibitors.

Neuroform Intracranial Stenting for Aneurysms Using Simple and Multi-stent Technique Is Associated With Low Risk of Magnetic Resonance Diffusion-Weighted Imaging Lesions

BACKGROUND:

Detection of procedural thromboembolism by diffusion-weighted magnetic resonance imaging (MR-DWI+) can help identify and mitigate endovascular risk factors. Data remain scant on procedural MR-DWI+ following the use of the Neuroform open-cell design stent in aneurysm embolization.

OBJECTIVE:

We sought to evaluate the incidence of MR-DWI+ in Neuroform simple and multi-stent construct stenting for intracranial aneurysms in an attempt to delineate baseline risk and identify possible associated procedural factors.

METHODS:

Seventy-six patients receiving 97 Neuroform stents in the treatment of intracranial aneurysm were identified from a prospective database and eligible for inclusion in the study. Diffusion-weighted magnetic resonance imaging (MR-DWI) was obtained in all patients within 48 hours of the procedure and reviewed for the presence of MR-DWI+ with patient records reviewed for analysis of factors predisposing to these lesions.

RESULTS:

Patients were treated with single-stent Neuroform constructs in 57 cases (73%) and multi-stent Neuroform constructs in 21 cases (27%). Y-stent technique was used in 16 cases. MR-DWI+ was identified in 7 of 78 cases (9.0%), with MR-DWI+ in 0 of 10 subarachnoid hemorrhage cases. No MR-DWI lesions led to a permanent neurological deficit at discharge. There was no MR-DWI+ in patients treated with Y-stenting or multi-stent Neuroform constructs. The only factor associated with ipsilateral MR-DWI+ was target aneurysm location on an arterial sidewall over bifurcation (P = .01).

CONCLUSION:

The Neuroform stent carries a very low risk of MR-DWI+ compared with its closed-cell design counterpart. Subarachnoid hemorrhage and deployment of multiple stents in the same anatomical region in configurations such as the Y-stent construct did not increase the risk of acute procedural thromboembolism.

Stent-assisted coiling of intracranial aneurysms: predictors of complications, recanalization, and outcome in 508 cases

BACKGROUND AND PURPOSE

Self-expanding stents are increasingly used for treatment of complex intracranial aneurysms. We assess the safety and the efficacy of intracranial stenting and determine predictors of treatment outcomes.

METHODS

A total of 508 patients with 552 aneurysms were treated with Neuroform and Enterprise stents between 2006 and 2011 at our institution. A multivariate analysis was conducted to identify predictors of complications, recanalization, and outcome.

RESULTS

Of 508 patients, 461 (91%) were treated electively and 47 (9%) in the setting of subarachnoid hemorrhage. Complications occurred in 6.8% of patients. In multivariate analysis, subarachnoid hemorrhage, delivery of coils before stent placement, and carotid terminus/middle cerebral artery aneurysm locations were independent predictors of procedural complications. Angiographic follow-up was available for 87% of patients at a mean of 26 months. The rates of recanalization and retreatment were, respectively, 12% and 6.4%. Older age, previously coiled aneurysms, larger aneurysms, incompletely occluded aneurysms, Neuroform stent, and aneurysm location were predictors of recanalization. Favorable outcomes were seen in 99% of elective patients and 51% of subarachnoid hemorrhage patients. Patient age, ruptured aneurysms, and procedural complications were predictors of outcome.

CONCLUSIONS

Stent-assisted coiling of intracranial aneurysms is safe, effective, and provides durable aneurysm closure. Higher complication rates and worse outcomes are associated with treatment of ruptured aneurysms. Stent delivery before coil deployment reduces the risk of procedural complications. Staging the procedure may not improve procedural safety. Closed-cell stents are associated with significantly lower recanalization rates.

Safety and efficacy of neuroform for treatment of intracranial aneurysms: a prospective, consecutive, French multicentric study

BACKGROUND AND PURPOSE

Endovascular embolization of wide-neck intracranial aneurysms can be technically challenging, especially when the anatomy is complex. Stent reconstruction of the parent artery is commonly used to treat wide-neck and bifurcated aneurysms. The main objective of this study was to investigate the periprocedural and midterm morbidity and mortality results of this procedure.

MATERIALS AND METHODS

SENAT is a consecutive, prospective, multicentric study. Patients with unruptured cerebral aneurysms who underwent endovascular treatment with the Neuroform stent system were recruited and recorded. Technical outcomes and complications were also assessed. The midterm anatomic results were re-evaluated at 12-18 months.

RESULTS

A total of 113 stents were used to treat the 107 aneurysms in 107 patients. The mean width of the aneurysm sac was 6.2 mm, and the mean diameter of aneurysm neck was 4.5 mm. The complete occlusion rate postprocedure was 66.4%. The rate of progressive occlusion at 12-18 months was 14%, and the rate of recurrence was 9.7%. The rate of subsequent treatment was 4%. The thromboembolic rate in the periprocedural period was 3.7%, and the rate of delayed TE events was 3%. Overall, the mortality rate at 12-18 months was 1%, and the permanent morbidity rate was 1%.

CONCLUSIONS

Stent-assisted coiling with the Neuroform stent system provides a high level of occlusion with low rates of subsequent treatment despite a predominant population of patients with wide-neck aneurysms. Morbidity and thromboembolic rates were comparable to studies investigating stand-alone coiling.

Stent-assisted coil emboilization of ruptured intracranial aneurysms: A retrospective multicenter review

Background:

The purpose of this study is to retrospectively review our experience with stent-assisted embolization of patients with an acutely ruptured cerebral aneurysm.

Methods:

Medical records and imaging were reviewed for 36 patients who underwent stent-assisted embolization of a ruptured cerebral aneurysm.

Results:

Seventeen patients (47%) received a preprocedural loading dose of clopidogrel and five patients (14%) received an intraprocedural dose of clopidogrel. The remaining 14 patients (36%) were treated with antiplatelet therapy following the procedure. Six (17%) stent related intraprocedural thromboembolic complications were encountered; four of these resolved (one partial, three complete) following treatment with abciximab and/or heparin during the procedure. Five of the six thromboembolic events occurred in patients who were not pretreated with clopidogrel (P = 0.043). Two patients in this series (6%) had a permanent thrombotic complication resulting in mild hemiparesis in one patient, and hemianopsia in the second. No procedure related hemorrhagic complications occurred in any patient. One patient had a spontaneous parenchymal hemorrhage contralateral to the treated aneurysm discovered 10 days after treatment. Twenty-eight patients (78%) had a Glasgow Outcome Score of 4 or better at discharge. Seven of 21 patients (33%) with angiographic follow-up required further treatment of the coiled aneurysm.

Conclusion:

Stent-assisted coil embolization is an option for treatment of ruptured wide neck ruptured aneurysms and for salvage treatment during unassisted embolization of ruptured aneurysms but complications and retreatment rates are higher than for routine clipping or coiling of cerebral aneurysms. Pretreatment with clopidogrel appears effective in reducing thrombotic complications without significant increasing risk of hemorrhagic complications.

Delayed ipsilateral parenchymal hemorrhage following flow diversion for the treatment of anterior circulation aneurysms

BACKGROUND AND PURPOSE

The PED is a flow-diverting stent designed for the treatment of cerebral aneurysms. We report 4 cases of delayed ipsilateral IPH following the technically successful treatment of anterior circulation aneurysms with the PED.

MATERIALS AND METHODS

Clinical and imaging data from all patients undergoing aneurysm treatment with the PED at 2 institutions were analyzed to assess the incidence of delayed IPH after treatment with the PED.

RESULTS

A total of 66 patients (47 anterior circulation) with cerebral aneurysms underwent treatment with a PED between January 2008 and November 2010. Four patients experienced delayed periprocedural IPH, all after the treatment of anterior circulation aneurysms (8.5%, 4/47). The aneurysm size ranged from 5 to 21 mm. All IPHs occurred within the cerebral hemisphere, ipsilateral to the treated aneurysm, and were anatomically remote from the treated aneurysms. All procedures were uncomplicated, and patients emerged from general anesthesia at neurologic baseline. The hemorrhages became clinically evident between 1 and 6 days after the procedure. Two patients had unfavorable outcomes (mRS scores, 4 and 6).

CONCLUSIONS

Delayed IPH may occur after the treatment of anterior circulation aneurysms with flow diverters. This complication does not seem to be restricted to a specific aneurysm subtype and does not seem to be related to an intraprocedural complication or solely attributable to DAT.

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

Purpose

Stent-assisted coiling allows embolization and parent vessel reconstruction of wide-necked intracranial aneurysms. The Neuroform EZ (Boston Scientific, Fremont, CA, U.S.A.) stent delivery system offers deployment of a Neuroform stent with fewer steps and improved operator control. Initial experience, technical considerations, and treatment outcomes using the Neuroform EZ stent delivery system in combination with coil embolization are reported.

Materials and Methods

Seventeen consecutive patients harboring 21 wide-necked saccular cerebral aneurysms were treated with stent reconstruction. Twenty aneurysms were unruptured; one was treated within 24 hours of diagnosis of rupture. Twenty aneurysms were located in the anterior circulation; one was in the posterior circulation. Immediate and six-month post-treatment angiography and clinical assessment were performed.

Results

In all cases, the stents were delivered and positioned without difficulty in deployment. Technical complications occurred in 4 patients, but none were directly related to the stent delivery system. On immediate post-treatment angiography, 5 of 21 aneurysms showed complete occlusion, 5 of 21 showed residual neck, and 11 of 21 showed residual contrast filling of the aneurysm sac. At six month follow-up, all 17 patients were clinically stable. Angiography of 18 of the aneurysms showed total occlusion in 12, residual neck in 3, and residual aneurysm filling in 3. Retreatment was performed in the three with residual aneurysm.

Conclusion

The Neuroform EZ stent system offers improved anchoring and support in stent delivery, which is particularly useful when multiple stents are overlapped to further protect the parent vessel and increase flow diversion away from the aneurysm sac. The only significant problem encountered was coil prolapse, which could be treated with a second stent when necessary. The ease of deployment improves upon the already clinically successful Neuroform design.