Pipeline Embolization Device with or without Adjunctive Coil Embolization: Analysis of Complications from the IntrePED Registry

Clinical Outcomes On Tubridge Flow Diverter in Treatmenting Intracranial Aneurysms: a Retrospective Multicenter Registry Study

PURPOSE

In China, the application of nitinol Tubridge flow diverter (TFD) has become popular for treating intracranial aneurysms (IAs). In this study, we investigated the safety outcomes of the application of TFD for treating IAs in real-world scenarios.

METHODS

We retrospectively analyzed aneurysms treated with TFD in 235 centers throughout China between April 2018 and April 2020. The primary endpoint was the event-free survival rate at 12 months, defined as the occurrence of morbidity (spontaneous rupture, intraparenchymal hemorrhage (IPH), ischemic stroke, and permanent cranial neuropathy) or death. Univariate and multivariate analyses were performed to assess the risk factors. A good outcome was defined as a modified Rankin Score (mRS) of 0-2.

RESULTS

We included 1281 unruptured aneurysms treated with TFD. The overall neurological morbidity and death rates after 12 months were 5.4 and 2.8%, respectively. Ischemic strokes were the most common complication (4.2%, P < 0.001). Cranial neuropathy, IPH, and spontaneous rupture occurred in 0.3%, 0.3%, and 0.5% of aneurysms, respectively. Univariate and multivariate analyses indicated that the male gender, older age, larger aneurysm diameter, and aneurysm located on BA were the independent risk factors for neurologic events. Aneurysm located on BA was the independent risk factor for ischemic strokes. Most patients (1222) had access to the mRS, and 93.2% of them achieved good outcomes.

CONCLUSION

Treatment of IAs with TFD was associated with low morbidity and mortality, most of which were ischemic events. Large posterior aneurysms might be associated with a higher complication rate.

TRIAL REGISTRATION

Retrospectively registered.

Pipeline embolization device versus Atlas stent assisted coiling for intracranial aneurysm treatment: a retrospective, propensity score matched study with a focus on midterm outcomes and hospital costs

BACKGROUND

Stent assisted coiling (SAC) and flow diverters (FDs) are common endovascular treatments for wide necked cerebral aneurysms, but studies comparing the new generation Atlas SAC and FDs are scarce. We performed a propensity score matched (PSM) cohort study to compare the Atlas SAC and the pipeline embolization device (PED) for proximal internal carotid artery (ICA) aneurysms.

METHODS

Consecutive ICA aneurysms treated at our institution with either the Atlas SAC or PED were studied. PSM was used to control for age, sex, smoking, hypertension, and hyperlipidemia, and the rupture status, maximal diameter, and neck size of the aneurysm (aneurysms >15 mm and non-saccular aneurysms were excluded). Midterm outcomes and hospital costs were compared between these two devices.

RESULTS

A total of 309 patients with 316 ICA aneurysms were included. Following PSM, 178 aneurysms treated with the Atlas SAC and PED were matched (n=89 in each group). Aneurysms treated with the Atlas SAC required a slightly longer procedure time, but had lower hospital costs than those treated with the PED (115.2±24.6 vs 102.4±40.8 min, P=0.012; $27 650.2±$6961.4 vs $34 107.0±$3707.2, P<0.001). Atlas SAC and PED treatments showed equivalent aneurysm occlusion rates (89.9% vs 86.5%, P=0.486), complication rates (5.6% vs 11.2%, P=0.177), and a favorable functional outcome (96.6% vs 97.8%, P=1.0) at follow-up (8.2±3.0 vs 8.4±4.2 months, P=0.652).

CONCLUSION

In this PSM study, midterm outcomes of the PED and Atlas SAC in the treatment of ICA aneurysms were similar. However, SAC required a longer operation time, and the PED may increase the economic cost of inpatients in Beijing, China.

Flow diversion for unruptured fusiform aneurysms of the proximal middle cerebral artery

Background

Managing fusiform aneurysms of the proximal (M1) segment of the middle cerebral artery (MCA) is challenging due to difficulties in both surgical and endovascular treatment. In this study, we present our experience using flow diverter stents for managing unruptured M1 segment fusiform aneurysms.

Methods

We conducted a retrospective review of the database of our institution to identify all patients who underwent flow diversion treatment for unruptured M1 segment fusiform aneurysms. We collected data on patient demographics, aneurysm characteristics, complications, angiographic follow-up results, and clinical outcomes.

Results

A total of 10 patients (five male and five female patients) with 10 unruptured M1 segment fusiform aneurysms were included in the study. The average age of the patients was 48 years (range: 16-64 years); five patients had aneurysms smaller than 10 mm, four had aneurysms measuring between 10 and 25 mm, and one patient had an aneurysm larger than 25 mm. The successful deployment of flow-diverting stents was achieved in all cases. Procedure-related morbidity was observed in 10% of patients, but there were no deaths. All patients showed good outcomes (modified Rankin Scale score of 0-1); eight out of 10 patients had available follow-up angiography results with a mean follow-up period of 11.6 months (range: 6-24 months). Complete occlusion occurred in six out of eight reviewed cases (75%).

Conclusion

Our preliminary findings suggest that using flow diversion for treating unruptured fusiform aneurysms in the proximal MCA is feasible and safe, with a satisfactory rate of complete occlusion. However, further studies involving larger case series are needed to validate the durability and efficacy of this treatment approach.

Coiling embolization strategy for medium-to-giant-sized intracranial aneurysms treated with pipeline embolization device: a propensity score-weighted study

OBJECTIVES

We aim to investigate associations between different coil strategies and outcomes in the aneurysms treated by a pipeline embolization device (PED).

METHODS

Patients with medium-to-giant-sized aneurysms treated by PED were included. The total cohort was divided into PED-alone and PED-coiling groups, and the PED-coiling group was further divided into loose and dense packing subgroups. Multivariate logistic analyses and stabilized inverse probability of treatment weighting (sIPTW) were performed to investigate the relationships between coiling strategies and outcomes. Restricted cubic spline (RCS) curves were used to describe the coiling degree and angiographic outcome relationship.

RESULTS

A total of 398 patients with 410 aneurysms were included. Aneurysms treated with PED coiling had a lower incomplete occlusion rate (15.3% vs. 30.3%, p = 0.002), higher total perioperative complication rate (14.2% vs. 3.5%, p = 0.001), longer production time (142.14 min vs. 101.26 min, p < 0.001), and higher total cost ($45,158.63 vs. $34,680.91, p < 0.001) than those treated with PED alone. There were no differences in outcomes between the loose and dense packing subgroups. However, the total cost was higher in the dense packing group ($43,787.46 vs. $47,288.32, p = 0.001) than in the loose packing group. The result was still robust in the multivariate and sIPTW analyses. The RCS curves showed "L-shape" relationships between the coil degree and angiographic outcomes.

CONCLUSION

Compared with PED alone, PED coiling could improve aneurysm occlusion. However, it could also increase the total complication risk, prolong procedure time, and increase the total cost. Compared with loose packing, dense packing did not enhance the treatment effectiveness but increased the treatment cost.

CLINICAL RELEVANCE STATEMENT

The additional treatment effect from coiling embolization declines sharply after a certain point. Specifically, the aneurysm occlusion rate is roughly stable when the coil number is greater than 3 or the total coil length is longer than 150 cm.

KEY POINTS

• Compared with pipeline embolization device (PED) alone, PED combined with coiling can improve aneurysm occlusion. • Compared with PED alone, PED combined with coiling increases the total complication risk, cost, and prolongs procedure time. • Compared with loose packing, dense packing did not increase the treatment effectiveness but increased the cost.

Surpass embolization of intracranial aneurysms: Perspective from a 2-year longitudinal follow-up study across high volume comprehensive stroke centers

BACKGROUND

Surpass Streamline (SS; Stryker^©) is an over-the-wire first-generation flow diverter (FD). There is a scarcity of data on real-world outcomes and complications of this FD.

METHODS

A retrospective review of consecutive cases between January 2019 and July 2021 at two high-volume comprehensive stroke centers, involving SS was conducted.

RESULTS

Fifty-five patients harbored 69 treated aneurysms, of which 96% were in the internal carotid petrous to terminus segments and 88% were <10 mm in size, and 12% measuring 10-24 mm. Raymond Roy Grade 1 occlusion was noted in 55 aneurysms (79.7%) at 1 year. Median follow-up duration was 26 months (mean = 26.06). Major complications were seen in eight patients (14.5%; 95% CI 6.5-26.7) and mortality attributable to SS stenting complications occurred in two (4.3%) patients. Four (7.2%) had ophthalmologic thromboembolic complications and two had (3.6%) ischemic complications. Procedural complications occurred in 10 patients (18.18%; 95% CI 9.1-30.9). Technical complications during procedure (n = 3, 5.3%) were: "confirmed" distal middle cerebral artery (MCA) guidewire perforation; "suspected" distal MCA guidewire perforation causing post-procedural subarachnoid hemorrhage and internal carotid artery dissection causing ischemic stroke. Seizures were seen in 5 (9.09%) and carotid-cavernous fistula in 1 (1.8%). Multivariate regression analysis showed technical challenges significantly predicted occurrence of major complications (p = 0.001; R²= 0.39, F(13,43) = 2.15, p = 0.029). Univariate analysis showed technical challenges significantly predicted ophthalmological complications (R²= 0.06, F(1,55) = 4.04, p = 0.049) and major complications (R²= 0.21, F(1,55) = 15.11, p = 0.0002).

CONCLUSION

Large-scale future registry should focus on national data regarding SS safety, technical challenges, and procedural complications. We present one of the longest follow-ups for SS in literature.

Endovascular treatment of pediatric basilar artery aneurysms: case series and literature review

PURPOSE

Pediatric basilar artery aneurysms are rare and challenging to treat. Microsurgical options and standard endovascular coiling are often undesirable choices for treatment of this pathology. Additional endovascular strategies are needed.

METHODS

Presentation, diagnosis, and management of pediatric basilar aneurysms were reviewed, with an emphasis on endovascular treatment strategies. Our case series of 2 patients was presented in detail, one treated with flow diversion and vessel sacrifice and one treated with stent-assisted coiling. An extensive review of the literation was performed to find other examples of pediatric basilar artery aneurysms treated with endovascular techniques.

RESULTS

Twenty-nine studies met inclusion criteria. Fifty-nine aneurysms in 58 patients were treated using endovascular techniques. Mortality rate was 10.3% (6/58) and a poor outcome (GOS 1-3) occurred in 15.5% (9/58). There were 4 reported recurrences requiring retreatment; however, only 46.5% of patients had reported follow-up of at least 1 year. 71.1% (42/59) were dissecting aneurysms.

CONCLUSION

Basilar artery aneurysms in the pediatric population are rare, commonly giant and fusiform, and often not amenable to microsurgical or coiling techniques. The surrounding vasculature, location, size, and morphology of the aneurysm along with the durability of treatment must be considered in treatment decisions. With proper patient selection, stent-assisted coiling and flow diversion may increase the durability and safety of endovascular treatment in this population.

Tubridge flow diverter alone vs. Tubridge flow diverter and coils for the treatment of intracranial aneurysms: A propensity score matching analysis

Background

The study was designed to assess the clinical performance of a tubridge flow diverter (TFD) in the treatment of intracranial aneurysms and to compare the efficacy and safety between intracranial aneurysms treated with TFD alone and TFD combined with coiling.

Methods

In this retrospective study, patients treated with the TFD alone or TFD combined with coiling between June 2018 to November 2022 were included. The patient demographics, the characteristics of the aneurysm, and the treatment outcomes between the two groups were compared. Propensity score matching was performed to match the variables with a significant difference between groups.

Results

In the current study, data from 93 consecutive patients including 104 aneurysms treated with TFD were analyzed. In total, 43 patients with 49 aneurysms were treated with TFD alone, and 50 patients with 55 aneurysms were treated with TFD combined with coiling. Aneurysms in the TFD combined with the coiling group were larger (12.9 ± 8.6 vs. 8.7 ± 8.8 mm, P = 0.016) and more likely to be saccular (92.7% vs. 75.5%, P = 0.027) than in the TFD alone group. No significant difference was observed between the two groups in terms of perioperative complication rate. During the follow-up period, the complete occlusion rate in the TFD combined with the coiling group was higher (80.0% vs. 43.8%, P = 0.001) than in the TFD alone group. These results were further confirmed using a propensity score matching analysis.

Conclusion

TFD combined with coiling can be a safe and effective alternative option for the treatment of complex aneurysms. Given the potential risks of these therapeutic modalities, thus very careful consideration is required on an individual patient basis.

Coiling followed by staged flow diversion for large and giant intracranial aneurysms

Objective

Delayed aneurysm rupture is a fatal complication after flow diversion treatment for large and giant intracranial aneurysms. This study aimed to investigate the feasibility and safety of coiling first and followed by planned flow diversion to prevent delayed aneurysm rupture.

Methods

From January 2017 to December 2021 in two institutions, patients with unruptured intracranial aneurysms treated by coiling first and planned flow diversion were retrospectively collected. Data on demographic and aneurysmal characteristics, procedural details, and clinical and angiographic outcomes were reviewed.

Results

Thirty patients were included (7 Males and 23 Females; Median age 57 years). Aneurysmal size ranged from 11.8 to 26.8 mm, with a median value of 18.5 mm. All aneurysms were located within the intradural segment of internal carotid arteries. Coiling and planned flow diversion were successfully performed in all patients. The time interval between coiling and flow diversion was 3.9–6.7 weeks, with a median value of 5.2 weeks. No hemorrhagic or ischemic complications occurred during the procedures and follow-up. Complete or subtotal occlusion was achieved in 86.7% (26/30) at the last angiographic follow-up (median 6.7 months).

Conclusion

The preliminary data suggested that coiling unruptured intracranial aneurysms followed by planned flow diversion is both safe and effective. Further studies with larger cohorts are needed to verify the effect of this new strategy in preventing delayed rupture after flow diversion.

Thromboembolic Events Detected by Diffusion-Weighted Magnetic Resonance Imaging after Flow Diverter Treatment: The Impact of Procedure Time

BACKGROUND

Periprocedural thromboembolism is a serious complication of endovascular treatment for intracranial aneurysms. In addition to symptomatic ischemia, asymptomatic postprocedural diffusion-weighted image-positive lesions (DPLs) are considered important. However, few studies have reported significant risk factors associated with DPLs and symptomatic ischemic stroke after flow diverter (FD) treatment. This study aimed to investigate the frequency and risk factors associated with DPLs after FD treatment.

METHODS

Between November 2015 and December 2021, 84 patients harboring 85 untreated, unruptured intracranial aneurysms treated with FD were enrolled.

RESULTS

DPLs after FD treatment were confirmed in 74 patients (87.1%), among whom 69 (93.2%) were clinically asymptomatic. In the univariate analyses, age >55 years (P = 0.040), smoking (P = 0.023), preprocedural P2Y12 reaction unit value of >185 (P = 0.030), larger dome size of >9.3 mm (P = 0.013), and prolonged procedure time >80 minutes (P < 0.001) were significantly associated with postprocedural DPLs. In the multiple logistic regression model, only prolonged procedure time >80 minutes (odds ratio, 10.72; 95% confidence interval, 1.346-233.899; P = 0.023) was statistically significant. The mediator effect showed that the association between procedure time and the occurrence of DPLs was not significantly modified by any other factors, although only adjunctive coiling showed a tendency (P-value for interaction = 0.070).

CONCLUSIONS

Prolonged procedure time >80 minutes was the only identifiable factor related to postprocedural DPLs. Adjunctive coiling tended to mediate the effects of a prolonged procedure time on the occurrence of DPLs after FD treatment.

Treatment of ruptured intracranial aneurysms using the novel generation of flow-diverters with surface modification: A systematic review and meta-analysis

BACKGROUND

Surface modification of flow diverters (FDs) has been explored as a solution for reducing thrombotic risk of these devices, without necessarily using dual antiplatelet therapy (DAPT). If effective, this could pose a promising alternative for treatment of ruptured aneurysms not amenable to other modalities.

METHODS

We performed a comprehensive search of PubMed, MEDLINE, and Embase databases following Preferred Reporting Items for Systematic reviews and Meta-analyzes guidelines. We included articles reporting use of surface-modified FDs for treatment of ruptured aneurysms. Demographics, subarachnoid hemorrhage (SAH) severity, aneurysm characteristics, devices used, periprocedural complications, angiographic outcomes, and mortality were extracted for sample size-based weighted analysis.

RESULTS

Six studies comprising 59 patients with 64 aneurysms were included. Mean patient age was 56.6 ± 6.3 years and 60.6% (95% confidence interval [CI], 46.7-72.9%) were women. The anterior circulation was the location in 60.4% (95%CI, 45.5-73.5%) of aneurysms; 41.8% of the aneurysms were saccular (95%CI, 29.3-55.4%), 16.7% were fusiform (95%CI, 8.3-30.8%), 29.9% were dissecting (95%CI, 12.8-55.4%), 24.4% were blood-blister (95%CI, 15.2-36.7%), and 5.7% were mycotic (95%CI, 2-15.1%). Poor SAH grade was reported in 46.9% (95%CI, 33.3-60.9%). Adjunctive coiling was used in 33.2% (95%CI, 12.4-63.6%). Periprocedural thromboembolic and hemorrhagic complications occurred in 20% (95%CI, 7.1-45.1%) and 8.8% (95%CI, 3.7-19.5%), respectively. Complete occlusion was achieved in 76.4% (95%CI, 58.1-88.3%); no retreatments during follow-up were reported. Overall mortality was 15.1% (95%CI, 7.7-27.6%). There were no differences between single antiplatelet therapy (SAPT) and DAPT regimens with respect to periprocedural thromboembolic complications (P = 0.09), hemorrhagic (P = 0.834) complications, and mortality (P = 0.312).

CONCLUSION

Surface-modified FD treatment of ruptured aneurysms resulted in high rates of thromboembolic complications and acceptable rates of hemorrhagic complications. A considerable proportion of aneurysms were nonsaccular. Rates of complete occlusion were high and retreatment were low. Importantly, no statistically significant difference was found between SAPT and DAPT with respect to complications and mortality.

Pipeline flow diversion with adjunctive coil embolization for internal carotid artery aneurysms following an intradural component: results in 46 consecutive aneurysms from a Japanese single-center experience

In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6 mm; median neck width, 6.3 mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small (< 10 mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10 mm) aneurysms (P = .024). The median clinical follow-up was 22 months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively.

Vertebral artery dissection and associated ruptured intracranial pseudoaneurysm successfully treated with coil assisted flow diversion: A case report and review of the literature

Dissecting intracranial pseudoaneurysms (IPs) are associated with a high incidence of rupture and poor neurologic outcomes. Lesions in the posterior circulation are particularly malignant and pose even greater management challenges. Traditional management consists of microsurgical vessel sacrifice with or without bypass. Flow diversion (FD) in the setting of subarachnoid hemorrhage (SAH) represents a reconstructive treatment option and can be paired with coil embolization to promote more rapid thrombosis of the lesion. We report a case of a ruptured dissecting vertebral artery (VA) IP successfully acutely treated with coil-assisted FD. A 53-year-old male presented with a right V4 dissection spanning the origin of the posterior inferior cerebellar artery and associated ruptured V4 IP. The patient was treated with coil-assisted FD. Oral dual-antiplatelet therapy (DAPT) was initiated during the procedure, and intravenous tirofiban was used as a bridging agent. Immediate obliteration of the IP was achieved, with near-complete resolution of the dissection within 48 h. The patient made a complete recovery, and angiography at 6 weeks confirmed total IP obliteration, reconstruction of the VA, and a patent stent. The use of FD and DAPT in the setting of acute SAH remains controversial. We believe that coil-assisted FD in carefully selected patients offers significant advantages over traditional microsurgical and endovascular options. The risks posed by DAPT and potential for delayed thrombosis with FD can be effectively mitigated with planning and the development of protocols. We discuss the current literature in the context of our case and review the challenges associated with treating these often devastating lesions.

Postoperative occlusion degree after flow-diverter placement with adjunctive coiling: analysis of complications

BACKGROUND

Although coiling with a flow diverter may provide immediate dome protection, no studies have evaluated the effect on complications of postoperative occlusion degree immediately postoperatively. The purpose of this study was to determine whether postoperative occlusion degree immediately after flow-diverter placement with adjunctive coiling was associated with complications.

METHODS

All patients' data were collected from the post-market multi-center cohort study of embolization of intracranial aneurysms with a pipeline embolization device (PED) in China (PLUS) registry. We divided patients into those treated with a PED alone (PED-only (PO) group), those treated with a PED with coils and incomplete occlusion (PED + coils + incomplete occlusion (PCIO) group), and those treated with a PED with coils and complete occlusion (PED + coils + complete occlusion (PCCO) group).

RESULTS

We evaluated 1171 consecutive patients with 1322 aneurysms treated with a PED: 685 aneurysms were treated with PO, 444 with PCIO, and 193 with PCCO. The PCCO group had a higher rate of aneurysm occlusion at the last follow-up than the PCIO and PO groups (P<0.0001). Multivariate analysis of the predictors of ischemic stroke and modified Rankin Scale score (mRS) deterioration showed that PCCO was an independent predictor of ischemic stroke (HR, 2.03; 95% CI, 1.12 to 3.67; P=0.019) and mRS deterioration (HR, 2.59; 95% CI, 1.57 to 4.26; P<0.0001).

CONCLUSIONS

Although postoperative complete occlusion with a PED and adjunctive coiling can increase the rate of aneurysm occlusion, this approach may also increase the risk of ischemic stroke and lead to poor postoperative functional outcomes.

Pipeline Embolization Device for Intracranial Aneurysms in a Large Chinese Cohort: Complication Risk Factor Analysis

During intracranial aneurysm embolization with the Pipeline embolization device (PED), ischemic and hemorrhagic complications have been observed in cases among Western populations. The postmarket multicenter registry study on the embolization of intracranial aneurysms with the PED in China, i.e., the PLUS study, was performed to assess real-world predictors of complications and functional outcomes in patients treated with the PED in a Chinese population. All patients with intracranial aneurysms who underwent embolization using the PED between November 2014 and October 2019 across 14 centers in China were included. The study endpoints included preoperative and early postoperative (< 30 days) functional outcomes (modified Rankin scale [mRS] scores) and complications related to PED treatment at early postoperative and follow-up time points (3-36 months). Multivariate analysis was performed to identify risk factors for complications. A total of 1171 consecutive patients (mean age, 53.9 ± 11.4; female, 69.6% [813/1171]) with 1322 aneurysms were included in the study. Hypertension, basilar artery aneurysms, and successful deployment after adjustment or unsuccessful device deployment were found to be independent predictors of ischemic stroke, while the use of the Flex PED and incomplete occlusion immediately after treatment were protective factors. An aneurysm size > 10 mm, distal anterior circulation aneurysms, and adjunctive coiling were found to be independent predictors of delayed aneurysm rupture, distal intraparenchymal hemorrhage, and neurological compression symptoms, respectively. The rate of PED-related complications in the PLUS study was similar to that in Western populations. The PLUS study identified successful deployment after adjustment or unsuccessful device deployment and the degree of immediate postoperative occlusion as novel independent predictors of PED-related ischemic stroke in a Chinese population. ClinicalTrial.gov Identifier: NCT03831672.

Technical aspects of combined intrasaccular and endoluminal flow diversion

INTRODUCTION

The concurrent use of endoluminal flow diversion with coils is a viable option when treating complex or large aneurysms. Alternatives to coil embolization as an adjunctive treatment are currently limited. The Food and Drug Administration recently approved the Woven EndoBridge (WEB) device (Microvention, Aliso Viejo, California) as an intrasaccular flow diverter for wide-neck bifurcation aneurysms. We present the technical aspects of combined WEB device plus endoluminal flow diversion for the treatment of complex wide-necked intracranial aneurysms.

METHODS

A retrospective chart review of all patients treated via intrasaccular flow diversion at a single institution over the last 12 months was performed.

RESULTS

In total, seven patients underwent treatment of eight aneurysms via combined intrasaccular and endoluminal flow diversion. Of the seven patients, six were treated in a single setting. The most common aneurysm location was the posterior communicating artery. The majority of the aneurysms required steam shaping of the Via deployment catheter to place the WEB device orthogonally to the aneurysm dome. There were no complications.

CONCLUSIONS

We believe this is one of the first series reporting the combined use of the WEB device and endoluminal flow diversion for the treatment of intracranial aneurysms. This series demonstrates that the concurrent use of the WEB device with endoluminal flow diversion is safe for achieving immediate aneurysm treatment and may enhance the long-term durability in complex aneurysms.

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.

Pipeline Embolization Device With Adjunctive Coils for the Treatment of Unruptured Large or Giant Vertebrobasilar Aneurysms: A Single-Center Experience

Objective: To evaluate effectiveness and safety of Pipeline embolization device (PED) for large or giant verterbrobasilar aneurysms (LGVBAs), and to compare the therapeutic effects of PED with and without adjunctive coils. Methods: We retrospectively analyzed 21 cases of unruptured LGVBAs who were treated in our hospital with PED. These cases were divided into "PED group" and "PED with adjunctive coils group." We compared the aneurysm characteristics and treatment outcomes between the two groups. Results: The overall neurological complication rate was 28.6% (6/21) and the mortality rate was 4.8% (1/21). There were 12 patients in the PED group and nine in the PED with adjunctive coils group. There were no significant differences in age, smoking, hypertension, aneurysm size, aneurysm location, or operation time between the two groups. The complete aneurysm embolization rate and favorable outcome rate (modified Rankin Scale = 0,1) of the PED with adjunctive coils group was 78% (7/9) and 100% (9/9), respectively, which were both better compared with the PED group with 63.6% (7/11) and 83% (10/12), respectively. However, these differences were not statistically significant. Conclusion: The effectiveness and safety of PED for LGVBAs is acceptable. Treatment results did not differ between the PED and PED with adjunctive coils groups; therefore, whether coils should be used may depend the operator. Our results suggest that correct use of the coils does not increase complications. We suggest that PED with adjunctive coils should be used for some selected LGVBAs.

Pipeline Embolization device for intracranial aneurysms in a large Chinese cohort: factors related to aneurysm occlusion

Background and Purpose:

The Pipeline Embolization Device (PED, Covidien/Medtronic) is widely used to treat intracranial aneurysms. This PED in China post-market multi-center registry study (PLUS) investigated safety and effectiveness of the PED for intracranial aneurysms in the Chinese population.

Methods:

This was a panoramic, consecutive, real-world cohort registry study. Patients treated with PED with or without coils between November 2014 and October 2019 at 14 centers in China were included, and those treated by parent vessel occlusion or other stents were excluded. Study outcomes included angiographic evaluation of aneurysm occlusion, complications, in-stent stenosis, and predictors of aneurysm occlusion. A central committee reviewed all imaging and endpoint events.

Results:

In total, 1171 patients with 1322 intracranial aneurysms were included. The total occlusion rate was 81.4% (787/967) at mean follow-up of 8.96 ± 7.50 months, with 77.1% (380/493) occlusion in the PED alone and 85.9% (407/474) in the PED plus coiling group. On multi-variate analysis, female sex, hyperlipidemia, vertebral aneurysms, PED plus coiling, and blood flow detained to venous phase were significant predictors of aneurysm occlusion. In posterior circulation cohort, there was no variable associated with aneurysm occlusion. In-stent stenosis predictors included current smoking and cerebral sclerosis/stenosis.

Conclusion:

In the largest series on PED of multi-center date of China, data suggest that treatment with the flow-diverting PED in intracranial aneurysms was efficacious. The treatment of PED combined coiling and blood flow detained to venous phase after PED implant were associated with aneurysmal occlusion. The occlusion rate of vertebral aneurysms was higher than other location aneurysms.

Clinical Trial Registration:

ClinicalTrials.gov identifier: NCT03831672.

Flow diversion of fusiform intracranial aneurysms

Fusiform aneurysms are less common than saccular aneurysms, but have higher associated mortality and rebleeding rates. Recently, flow diversion has emerged as a possible treatment option. The purpose of this study was to determine the safety and efficacy of the Pipeline Embolization Device (PED) for the treatment of ruptured and unruptured fusiform aneurysms. This was a retrospective analysis of patients with fusiform intracranial aneurysms treated with a PED at a quaternary care center between January 2012 and September 2019. Occlusion rates, neurologic morbidity/mortality, and other clinical variables were analyzed. Twenty-nine patients with 30 fusiform aneurysms were treated with a PED. Sixteen aneurysms (53%) were located in the anterior circulation and 14 aneurysms (47%) were in the posterior circulation. The mean maximal diameter of the aneurysms was 10.1 ± 5.6 mm (range 2.3-25 mm). Angiographic and clinical follow-up were available for 28 aneurysms (93%). The median follow-up was 17.4 months (IQR 4.8 to 28 months) and occlusion rates were graded according to the O'Kelly-Marotta (OKM) scale. Of patients with DSA follow-up, 15 aneurysms (60%) were completely occluded (OKM D) and 19 aneurysms (76%) had a favorable occlusion result (OKM C1-3 and D). The overall complication rate was 26.7% with a neurological morbidity rate of 6.7% and neurological mortality rate of 3.4%. Flow diversion can be an effective treatment for both ruptured and unruptured fusiform aneurysms. Nevertheless, complete occlusion rates are lower than for saccular aneurysms. Therefore, flow diversion should be considered only if other more direct treatment options, such as clipping or stent/coiling are not applicable. Flow diversion should be used cautiously in patients presenting with rupture.

Endovascular Treatment of Giant Intracranial Aneurysms

Objective

Giant intracranial aneurysms (GIAs) are associated with a high risk of rupture and have a high mortality rate when they rupture (65-100%). The traditional microsurgical approach to secure these lesions is challenging, and as such endovascular embolization has been increasingly selected as a treatment option.

Methods

We performed a retrospective analysis of consecutive patients with ruptured and unruptured GIAs at three medical centers from October 2008 to April 2016. Clinical follow-up and digital subtraction angiography were conducted at six months post-treatment. Chi-square analysis was used to determine differences in outcomes between anterior and posterior circulation aneurysms and if a pipeline embolization device (PED) provided favorable outcomes in unruptured GIAs.

Results

A total of 45 consecutive patients (mean/median age = 57/59; range: 16-82 years) were included. The mean/median aneurysm size was 29.9/28.3 mm (range: 25-50 mm). Eight (18%) patients presented with aneurysmal subarachnoid hemorrhage and 37 (82%) with unruptured GIAs. Twenty-eight (62%) were treated with a PED: 11 (24.4%) with one PED, 1 (2.2%) with PED + coils, 11 (24.4%) with more than one PED, and 5 (13.5%) with multiple PED + coils. The overall mortality rate was 3/45 (6.7%). No deaths were procedure-related. Five (11.1%) patients experienced ischemic stroke but only 2 had a 90-day modified Rankin Scale (mRS) score of ≥3. Of 33 patients available for six-month angiography, Raymond scale (RS) scores were 1, 2, and 3 for 23/45 (70%), 7/45 (20.9%), and 3/45 (9.1%), respectively. Chi-square test demonstrated that overall, anterior circulation GIAs had better clinical (mRS score) and radiographic (RS score) outcomes than posterior GIAs. PED alone provided similar clinical mRS outcomes but had a higher rate of complete occlusion at six months compared with PED + coils and coils alone in unruptured GIAs (p < 0.05).

Conclusions

Endovascular embolization using PED or PED + coils appears to be a moderately safe and effective treatment option for patients with GIAs.

Immediate Postoperative Angiographic Stagnation of Contrast Media and T2-Weighted Magnetic Resonance Imaging Features within Aneurysmal Sac Are Associated with Early Regression of Large or Giant Aneurysm After Flow Diversion Only

BACKGROUND

We hypothesized that the immediate postoperative imaging features would be associated with early regression of flow-diverted aneurysms. We compared the imaging features from digital subtraction angiography and spin echo T2-weighted magnetic resonance imaging between those with early total regression and partial regression.

METHODS

A total of 30 consecutive patients with large and giant aneurysms were treated with pipeline embolization devices and divided into 2 groups according to the follow-up angiographic findings at 3-6 months. Of the 30 patients, 20 had had total or near total regression and 10 had had partial regression of the aneurysmal sac. The baseline characteristics, percent area of stagnated iodine contrast agent on anteroposterior and lateral angiographic views just after installation of the pipeline device, and median, minimal, and 10-percentile signal intensity of the aneurysmal sac on T2-weighted spin echo images 1 day after the procedure were compared between the 2 groups.

RESULTS

A comparison of the demographic data between the 2 groups showed no significant differences. The volume of the treated aneurysmal sac also did not differ significantly (2559.28 ± 3021.45 mm³ vs. 2551.76 ± 6550.58 mm³; P = 0.455). The total or near total regression group had a larger percent area of iodine stagnation on the lateral angiographic view compared with the partial regression group (52.26% vs. 23.35%; P = 0.002). The median, minimal, and 10-percentile signal intensity of the volume of interest were higher in the total or near total regression group than in the partial regression group (1.29 vs. 0.93 [P = 0.025]; 0.07 vs. 0.00 [P = 0.042]; 0.57 vs. 0.24 [P = 0.005]).

CONCLUSIONS

The percent area of contrast media stagnation on lateral angiograms and the median, minimal, and 10th-percentile signal intensity of the volume of interest of treated aneurysmal sacs on T2-weighted images can be used to predict early regression of aneurysmal sacs.

The Evolution of Flow-Diverting Stents for Cerebral Aneurysms; Historical Review, Modern Application, Complications, and Future Direction

In spite of the developing endovascular era, large (15–25 mm) and giant (>25 mm) wide-neck cerebral aneurysms remained technically challenging. Intracranial flow-diverting stents (FDS) were developed to address these challenges by targeting aneurysm hemodynamics to promote aneurysm occlusion. In 2011, the first FDS approved for use in the United States market. Shortly thereafter, the Pipeline of Uncoilable or Failed Aneurysms (PUFS) study was published demonstrating high efficacy and a similar complication profile to other intracranial stents. The initial FDA instructions for use (IFU) limited its use to patients 22 years old or older with wide-necked large or giant aneurysms of the internal carotid artery (ICA) from the petrous segment to superior hypophyseal artery/ophthalmic segment. Expanded IFU was tested in the Prospective Study on Embolization of Intracranial Aneurysms with PipelineTM Embolization Device (PREMIER) trial. With further post-approval clinical data, the United States FDA expanded the IFU to include patients with small or medium, wide-necked saccular or fusiform aneurysms from the petrous ICA to the ICA terminus. However, IFU is more restrictive in South Korea than in United States. Several systematic reviews and meta-analyses have sought to evaluate the overall efficacy of FDS for the treatment of cerebral aneurysms and consistently identify FDS as an effective technique for the treatment of aneurysms broadly with complication rates similar to other traditional techniques. A growing body of literature has demonstrated high efficacy of FDS for small aneurysms; distal artery aneurysms; non-saccular aneurysms posterior circulation aneurysms and complication rates similar to traditional techniques. In the short interval since the Pipeline Embolization Device was first introduced, FDS has been firmly entrenched as a powerful tool in the endovascular armamentarium. As new FDS are developed, established FDS are refined, and delivery systems are improved the uses for FDS will only expand further. Researchers continue to work to optimize the mechanical characteristics of the FDS themselves, aiming to optimize deploy ability and efficacy. With expanded use for small to medium aneurysms and posterior circulation aneurysms, FDS technology is firmly entrenched as a powerful tool to treat challenging aneurysms, both primarily and as an adjunct to coil embolization. With the aforementioned advances, the ease of FDS deployment will improve and complication rates will be further minimized. This will only further establish FDS deployment as a key strategy in the treatment of cerebral aneurysms.

Introduction: History and Development of Flow Diverter Technology and Evolution

The introduction of flow diverter technology to the field of neurointervention has revolutionized the treatment of intracranial aneurysms. The therapy approach has shifted from intrasaccular aneurysm treatment to exclusion of the aneurysm from the blood circulation with remodeling of the parent artery. Previously, “difficult”-to-treat aneurysms including fusiform and blister aneurysms, but also aneurysms arising from a diseased vessel segment, can now be safely and permanently treated with flow diverters.

 A little over a decade ago, after extensive bench testing and refinement of the flow diverter concept, the device was eventually available for clinical use and today it has become a standard treatment for intracranial aneurysms. Currently, United States Food and Drug Administration (FDA)-approved flow diverters are the Pipeline Embolization Device (Medtronic) and the Surpass Streamline Flow Diverter (Stryker).

 The devices can either be delivered or deployed via a standard femoral artery approach or a radial artery approach. Other considerations for catheter setup and device deployment strategies depending on aneurysm location or vessel anatomy are described.

Sequential Coiling-Assisted Deployment of Flow Diverter for Treatment of Fusiform Middle Cerebral Artery Aneurysms

BACKGROUND AND IMPORTANCE

Fusiform intracranial aneurysms remain challenging lesions to treat. These aneurysms have historically required bypass procedures or clip remodeling constructs for cure. Recently, endovascular specialists have reported experience with flow diversion for complex fusiform aneurysms of the vertebrobasilar system, with mixed results. Vascular anatomy for anterior circulation fusiform aneurysms may make these lesions more amenable to flow diversion and embolization procedures; however, published experience with these techniques is lacking. In this report, we describe a sequential coiling-assisted deployment of flow diverter for the treatment of fusiform middle cerebral artery (MCA-M1) aneurysms in 2 cases, 1 presenting acutely with subarachnoid hemorrhage and another with progressive aneurysm enlargement.

CLINICAL PRESENTATION

Two patients, a 36-yr-old male presenting with subarachnoid hemorrhage and a 60-yr-old female presenting with aneurysm enlargement were treated for fusiform aneurysms of the M1 segment of the MCA using a sequential, partial deployment of coils and flow diverter through 2 microcatheters to facilitate mutual mechanical support for both coil and flow diverter (Pipeline Embolization Device; Medtronic Inc, Dublin, Ireland). Both patients achieved favorable outcomes and follow-up angiography demonstrated complete vessel reconstruction in both cases.

CONCLUSION

The treatment of complex, fusiform, large vessel aneurysms remains challenging. As experience with new endovascular technologies and techniques grows, these lesions may be treated safely with interventional methods. The technique of partial flow diverter deployment and stabilization with coils with sequential delivery of both devices using dual microcatheter was both safe and effective.

Two- to five-year follow-up of 78 patients after treatment with the Flow Redirection Endoluminal Device

BACKGROUND AND PURPOSE

Flow-diverter stents are well-established for the treatment of cerebral aneurysms. Flow Redirection Endoluminal Device differs from other flow-diverter stents by its dual-layer design and has proved equality to other devices in numerous short-term surveys. However, follow-up data covering substantially more than one year are still limited for this device. We present our long-term experience with Flow Redirection Endoluminal Device.

MATERIALS AND METHODS

Seventy-eight patients harboring distal internal carotid artery (91%) or vertebrobasilar (9%) cerebral aneurysms treated with Flow Redirection Endoluminal Device with or without adjunctive coiling met the inclusion criteria. All cases were evaluated for aneurysm occlusion (according to Modified Raymond Roy Classification, MRRC), for flow-diverter stents patency and configuration and for procedure- and device-related morbidity and mortality.

RESULTS

Mean follow-up interval was 36.9 ± 9.5 months (<30 months: n = 18; 31-42 months: n = 31; >42 months: n = 24). Total and subtotal aneurysm occlusion after six months was assessed in 92.0% (MRRC₁ = 77.3%, MRRC₂ = 14.7%, MRRC_3a =2.7%, MRRC_3b = 4.1%) and increased to 95.9% (MRRC₁ = 90.5%, MRRC₂ = 5.4%, MRRC_3a = 2.7%). There was one case of aneurysm growth requiring early re-treatment. Procedure-related morbidity was observed in three cases (3.8%; one transient hemiparesis, one suspected foreign-body reaction, and one micro-wire perforation). There was no procedure- or device-related mortality. In-stent stenosis due to intimal hyperplasia was observed in two cases and fish-mouthing in three cases.

CONCLUSIONS

Our long-term data covering two to five years after flow diversion confirm that Flow Redirection Endoluminal Device is a safe and effective device for the treatment of cerebral aneurysms with progressive high aneurysm occlusion rates; recurrence rates were very low. Overall device-related morbidity was low and was not observed later than six months after intervention.

Initial Treatment for Unruptured Intracranial Aneurysm and Its Follow-up: A Cost Analysis of Pipeline Flow Diverters versus Coiling

Purpose

Intracranial aneurysms are relatively common epidemiological problems for which the surveillance, treatment, and follow-up are costly. Although multiple studies have evaluated the treatment cost of aneurysms, the follow-up costs are often not examined. In our study, we analyzed how follow-up costs after treatment affected the overall cost of different endovascular techniques for treating aneurysms.

Materials and methods

An institutional database was used to evaluate the upfront and follow-up costs incurred by patients who underwent elective coiling or placement of a pipeline embolization device (PED) for the treatment of unruptured intracranial aneurysms from July 2011 to December 2017.

Results

A total of 114 patients (coiling, n = 37; PED, n = 77 ) were included in the study. There was no significant difference among patients in mean age [61.3 (±12.8 years) vs. 57.0 (±14.5 years); probability value (p) = 0.2], sex (male: 32.4% vs. 22.1%; p = 0.2), American Society of Anesthesiologists (ASA) grade (p = 0.5), discharge disposition (p = 0.1), mean length of stay [3.1 days (±5.5) vs. 2.4 days (±2.6); p = 0.2) or follow-up period [22.7 months (±18.5) vs. 18.6 months (±14.9); p = 0.2). There were no differences in costs during admission (p = 0.5) or in follow-up (p = 0.3) between coiling and PED treatments. Initial costs were predominantly related to supplies/implants (56.1% vs. 63.7%) for both treatments. Follow-up costs mostly comprised facility costs (68.2% vs. 67.5%), and there were no differences in costs of subgroups such as supplies/implants (10.5% vs. 9.4%), imaging (17.0% vs. 17.8%), or facilties between coiling and PED.

Conclusion

These results suggest that the upfront and follow-up costs are mostly similar for the treatment of intracranial aneurysms irrespective of whether the providers used coiling or PED endovascular techniques. Hence, we conclude that follow-up costs should not be a deciding factor when considering these treatments.

TARGET® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis of Peri-Procedural and Long-Term Safety and Efficacy Results

Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.

Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A secondary analysis investigated the influence of the use of 100% 360-complex coils on clinical and angiographic outcomes.

Results: 148 patients with 157 aneurysms met the inclusion and exclusion criteria. 58 (39.2%) patients with ruptured and 90 (61.8%) with unruptured aneurysms were treated using TARGET 360°, helical Coils, or both. Median age was 58.3 (IQR 48.1–67.4), 73% female, and 71.6% were Caucasian. Median follow-up time was 5.9 (IQR 4.0–6.9) months. The majority were treated with TARGET 360-coils (63.7%), followed by mixed and helical coils only. Peri-procedural morbidity and mortality was seen in 2.7% of patients. A good outcome at discharge (mRS 0–2) was seen in 89.9% of the full cohort, and in 84.5 and 93.3% in the ruptured and unruptured patients, respectively. The median packing density was 28.8% (IQR 20.3–41.1). Long-term complete and near complete occlusion rate was seen in 90.4% of aneurysms and complete obliteration was seen in 66.2% of the aneurysms. No significant difference in clinical and angiographic outcomes were noted between the pure 360-complex coiling vs. mixed 360-complex/Helical coiling strategies. In a multivariate analysis, predictors for long-term aneurysm occlusion were aneurysm location, immediate occlusion grade, and aneurysm size. The long-term independent functional outcome was achieved in 128/135 (94.8%) patients and all-cause mortality was seen in 3/148 (2%) patients.

Conclusion: In the multicenter TARGET Registry, two-thirds of aneurysms achieved long-term complete occlusion and 91.0% achieved complete or near complete occlusion with excellent independent functional outcome.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT01748903

Predictors of Clinical Outcome After Treatment of Intracranial Aneurysms with the Pipeline Embolization Device

BACKGROUND

Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED).

METHODS

A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed.

RESULTS

We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (≤10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (≥25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events.

CONCLUSIONS

The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.

Effect of aneurysm morphologic parameters on occlusion rates following pipeline embolization

OBJECTIVE

Treatment failures with the use of Pipeline Embolization Device (PED) continue to be observed in up to 18% of patients in large case series. Adjunctive coiling and layering of multiple devices have been shown to improve occlusion rates; however, the optimal treatment strategy with the use of PED has not been established. The purpose of this study is to identify morphological characteristics predictive of treatment failure after PED.

PATIENT AND METHODS

A case control design was used to evaluate the association of aneurysm morphologic parameters with failure after PED placement. Retrospective analysis of patients undergoing PED for elective aneurysm treatment between 2014 and 2017 was performed. Patients who underwent PED placement with at least 12 months follow-up using conventional cerebral angiography were included for further review.

RESULTS

84 patients met inclusion criteria for further analysis. ten patients (11.9%) experienced treatment failure defined by retained flow within the aneurysm and of those eight patients (9.5%) required additional retreatment. On multivariate analysis decreasing aspect ratio and increasing neck width were significant parameters that predicted treatment failure.

CONCLUSION

Aneurysms with small aspect ratio and large neck width may be more likely to experience treatment failure after PED embolization. This subset of aneurysms may therefore benefit from adjunctive coiling to improve occlusion rates. Future prospective studies are needed to validate these findings.

Predicting Outcomes for Cerebral Aneurysms Treated with Flow Diversion: A Comparison Between 4 Grading Scales

OBJECTIVE

Despite the development of 4 grading scales of angiographic outcome after flow diversion for cerebral aneurysms, none have been widely adopted in the neurosurgical literature, nor have any been validated in an independent dataset. We evaluated the reported grading scales for their ability to predict aneurysm occlusion at follow-up.

METHODS

Four reported grading scales were applied in a retrospective analysis of our prospectively maintained institutional database of patients with intracranial aneurysms treated with flow-diverting stents. Analysis of patient factors, aneurysm factors, and outcomes was made to compare the grading scales' ability to predict aneurysm occlusion.

RESULTS

Ninety-nine aneurysms in 90 patients treated at our institution between 2011 and 2018 were included in the analysis. Lower Flow-Diverting Stent Score (FDSS) scores were associated with higher rates of aneurysm occlusion at final follow-up (P=0.004). The OKM, Kamran-Byrne, and SMART scales scores were not associated with aneurysm occlusion at final follow-up even after adjustments for baseline differences. Area under the receiver operating characteristic curve for the FDSS was 0.675 (0.534-0.816).

CONCLUSIONS

Although the FDSS was the only reported grading scale that was significantly associated with occlusion at follow-up, its ability to predict occlusion fell below the typical level for widespread clinical utility. The high rate of eventual occlusion of most aneurysms after flow diversion likely limits the clinical utility of a grading score for this application.

Aneurysm Remnants after Flow Diversion: Clinical and Angiographic Outcomes

BACKGROUND AND PURPOSE

Flow diversion is an established method to treat complex intracranial aneurysms. The natural history of flow-diversion treatment failure resulting in aneurysm remnants is not well-defined. We aimed to delineate the clinical and angiographic features of this entity.

MATERIALS AND METHODS

Review of a prospectively maintained Pipeline Embolization Device data base from inception to October 2017 was performed for aneurysms that demonstrated residual filling on follow-up imaging. Procedural and follow-up clinical details were recorded. Independent, blinded, angiographic assessment of occlusion was performed on the basis of the O'Kelly-Marotta scale. Aggregated outcomes were analyzed using the Fisher exact and Mann-Whitney U tests for categoric and continuous variables, respectively (statistical significance, α = .05).

RESULTS

During the study period, 283 sequential patients were treated; 87% (246/283) were women. The median patient age was 55 years (interquartile range, 47-65 years). Six-month follow-up imaging was available in 83.7% (237/283) of patients, which showed 62.4% (148/237) complete occlusion (class D, O'Kelly-Marotta grading scale). Adjunctive coiling (P = .06), on-label Pipeline Embolization Device use (P = .04), and multiple device constructs (P = .02) had higher rates of complete occlusion at 6 months. Aneurysm remnants were identified in 25 cases on long-term follow-up imaging (median, 16 months; interquartile range, 12-24 months). No patient with an aneurysm remnant after flow diversion presented with delayed rupture or other clinical sequelae, with a median clinical follow-up of 31 months (interquartile range, 23-33 months).

CONCLUSIONS

Aneurysm remnants after flow diversion are infrequent with minimal clinical impact. When appropriate, the presence of overlapping devices and possibly adjunctive coiling may result in higher rates of complete occlusion.

Endovascular Reconstruction of Intracranial Aneurysms with the Pipeline Embolization Device in Pediatric Patients: A Single-Center Series

Background

Pediatric intracranial aneurysms tend to differ in etiology, size, and location from their adult counterparts, and they are often less amenable to microsurgical clip reconstruction techniques. Endovascular treatment with detachable coils is an accepted treatment technique for pediatric patients, though high recurrence rates have been reported with coil embolization of large and giant aneurysms in this population. While the Pipeline Embolization Device (PED) is FDA-approved for adult intracranial aneurysms, the use of PEDs in pediatric patients is considered off-label.

Case Descriptions

We present 3 cases of pediatric intracranial aneurysms in a 5-year-old male, a 12-year-old male, and a 12-year-old female who presented with symptoms including seizure, headache, and blurred vision. The 2 male patients were found to have intradural vertebral artery saccular aneurysms, while the female patient had a paraophthalmic right internal carotid complex aneurysm. After endovascular reconstruction of the aneurysms with PEDs, follow-up angiography showed complete occlusion of the previous aneurysms with no residual aneurysm filling in all 3 cases.

Conclusion

While further investigation is needed, the evidence presented here supports the conclusion that the PED can be an effective and viable treatment strategy in the pediatric population.

The Role of Collateral Circulation in Branch Vessel Occlusion After Flow Diversion

BACKGROUND

Flow diversion for treatment of intracranial aneurysms frequently necessitates covering adjacent branch vessels. Although branch vessel occlusion is common, associated clinical deficits are rare. It has been hypothesized that clinically silent branch vessel occlusion is due to underlying collateral circulation. To study the role of collateral circulation in covered branch vessel occlusion, we assessed collateral vessels and altered branch vessel flow on transfemoral catheter angiography in patients undergoing flow diversion of intracranial aneurysms.

METHODS

Angiograms obtained before treatment, immediately after treatment, and during follow-up were evaluated for branch vessel flow patterns and associated collateral circulation in a consecutive retrospective cohort of 84 patients from 2011 to 2017 with branch vessel coverage related to aneurysm flow diversion using the Pipeline embolization device.

RESULTS

We identified 142 branch vessels covered by the Pipeline device construct for treatment of 89 aneurysms, predominately in the anterior circulation (>90%). Collateral circulation was observed in approximately one third of these vessels and was associated with diminished (P < 0.001) or absent (P < 0.001) flow on follow-up angiography. Only 2 of 80 terminal branch vessels (no collaterals) were occluded, and these occurred in a patient with Pipeline device construct thrombosis. Altered branch vessel flow was not associated with vascular risk factors, treatment technique, or outcome measures, including new or worsening neurologic deficit.

CONCLUSIONS

Altered flow in branch vessels covered during flow diversion reflects underlying collateral circulation and is not associated with downstream ischemic deficits.

Pipeline-assisted coiling versus pipeline in flow diversion treatment of intracranial aneurysms

BACKGROUND AND PURPOSE

Flow-diversion therapy (FDT) for large and complex intracranial aneurysms is effective and considered superior to primary coil embolization. Data evaluating common treatment with both FDT and coiling continues to emerge, but information on outcomes remains scarce. This study aims to examine further the efficiency and outcomes correlated with joint FDT using pipeline embolization device (PED) and coiling compared to PED-alone in treating intracranial aneurysms.

MATERIALS AND METHODS

Comparative review and analysis of aneurysm treatment with PED in 416 subjects were conducted. Joint modality, PED, and coiling were compared to PED-alone for aneurysm occlusion, recurrence, retreatment, thromboembolic or hemorrhagic events, and functional outcome using the modified Rankin Scale. Data on patient demographics, aneurysm characteristics, clinical and angiographic follow up, were also collected. Both univariate analysis and multivariate logistic regression modeling using mixed-effects were performed.

RESULTS

Total of 437 aneurysms were treated using PED of which 74 were managed with both PED and coiling. Average patient-age was 56 years, the majority were men (85%), an average aneurysm size was 9 mm, and the majority were saccular aneurysms (84%). Larger aneurysm size was associated with a poor outcome in patients with unruptured aneurysms (OR = 1.06). Adjusted regression analyses revealed no differences between treatment groups in thromboembolic or hemorrhagic events, aneurysm occlusion rate, residual flow on follow up angiography, or functional outcome.

CONCLUSIONS

Treatment of intracranial aneurysms with joint PED and coiling was safe with no increase in complications when compared to PED alone. Aneurysm occlusion rates and functional outcome with PED and coiling stays comparable to treatment with PED-alone.

A new method to statistically describe microcatheter tip position in patient-specific aneurysm models

BACKGROUND AND PURPOSE

Evidence on how to select microcatheters to facilitate aneurysm catheterization during coil embolization is sparse. We developed a new method to define microcatheter tip location inside a patient-specific aneurysm model as a 3-dimensional probability map. We hypothesized that precision and accuracy of microcatheter tip positioning depend on catheter tip shape and aneurysmal geometry.

MATERIALS AND METHODS

Under fluoroscopic guidance two to three operators introduced differently shaped microcatheters (straight, 45°, 90°) into eight aneurysm models targeting the anatomic center of the aneurysm. Each microcatheter position was recorded with flat-panel CT, and 3-dimensional probability maps of the microcatheter tip positions were generated. Maps were assessed with histogram analyses and compared between tip shapes, aneurysm locations and operators.

RESULTS

Among a total of 530 microcatheter insertions, the precision (mean distance between catheter positions) and accuracy (mean distance to target position) were significantly higher for the 45° tip (1.10±0.64 mm, 3.81±1.41 mm, respectively) than for the 90° tip (1.27±0.57 mm, p=0.010; 4.21±1.60 mm p=0.014, respectively). Accuracy was significantly higher in posterior communicating artery aneurysms (3.38±1.20 mm) than in aneurysms of the internal carotid artery (4.56±1.54 mm, p<0.001).

CONCLUSION

Our method can be used tostatistically describe statistically microcatheter behavior in patient-specific anatomy, which may improve the available evidence guiding microcatheter shape selection. Experience increases the ability to reach the intended position with a microcatheter (accuracy) that is also dependent on the aneurysm location, whereas catheter tip choice determines the variability of catheter tip placements versus each other (precision). Clinical validation is required.

Single-stage flow diversion with adjunctive coiling for cerebral aneurysm: outcomes and technical considerations in 72 cases

Background

Adjunctive coiling may improve occlusion outcomes when combined in a single stage with cerebral aneurysm flow diversion. This technique has not been well described.

Objective

To present a series of aneurysm patients treated by single-stage flow diversion with adjunctive coiling, describing technical considerations and outcomes.

Methods

This was a retrospective cohort study using an IRB-approved database of procedures performed at a single institution. Treatment selection was based on large aneurysm size, morphological irregularity, branch vessel location, and wide neck.

Results

A total of 72 Pipeline with adjunctive coiling (PAC) procedures were performed on 69 patients. Average aneurysm size was 11.0 mm and 86% were wide-necked. Three progressively complex techniques were performed approximately equally: 27 sequential (38%), 23 jailed single-intermediate (32%), and 22 bifemoral jailed microcatheter (31%) cases. Aneurysm dome (P=0.0223) and neck size (P=0.001) increased with procedural complexity and there was a trend toward increased procedure length, radiation exposure, and stent thrombosis. A ‘light’ coil pack was used with an average packing density of 14% that did not vary by technique. Of the three major complications (4.2%), none were observed with the sequential approach (0%), one with the jailed single-intermediate (4.3%), and two with bifemoral cases (9.1%) (P=0.116). Complete occlusion was achieved in 85% of PAC cases at 6 months and 96% at 12-month follow-up angiography.

Conclusions

There are multiple approaches to flow diversion with adjunctive coiling, each with technical challenges, suitable to different types of aneurysms. Flow diversion with coiling can expedite and improve occlusion outcomes without a significant increase in morbidity.

Flow diversion of tandem cerebral aneurysms: a multi-institutional retrospective study

OBJECTIVE Flow diversion has proven to be an efficacious means of treating cerebral aneurysms that are refractory to other therapeutic means. Patients with tandem aneurysms treated with flow diversion have been included in larger, previously reported series; however, there are no dedicated reports on using this technique during a single session to treat this unique subset of patients. Therefore, the authors analyzed the outcomes of patients who had undergone single-session flow diversion for the treatment of tandem aneurysms. METHODS The authors conducted a retrospective review of flow diversion with the Pipeline embolization device (PED) for the treatment of tandem aneurysms in a single session at 2 participating medical centers: University of Utah, Salt Lake City, Utah, and Barrow Neurological Institute, Phoenix, Arizona. Patient demographic data, aneurysm characteristics, treatment strategy and results, complications, and follow-up data were collected from the medical record and analyzed. RESULTS Between January 2011 and December 2015, 17 patients (12 female, 5 male) with a total of 38 aneurysms (mean size 4.7 ± 2.7 mm, mean ± SD) were treated. Sixteen patients had aneurysms in the anterior circulation, and 1 patient had tandem aneurysms in the posterior circulation. Twelve patients underwent only placement of a PED, whereas 5 underwent adjunctive coil embolization of at least 1 aneurysm. One PED was used in each of 9 patients, and 2 PEDs were required in each of 8 patients. There were 2 intraprocedural complications; however, in both instances, the patients were asymptomatic at the last follow-up. The follow-up imaging studies were available for 15 patients at a mean of 7 months after treatment (216 days, range 0-540 days). The mean initial Raymond score after treatment was 2.7 ± 0.7, and the mean final score was 1.3 ± 0.7. CONCLUSIONS In this series, the use of flow diversion for the treatment of tandem cerebral aneurysms had an acceptable safety profile, indicating that it should be considered as an effective therapy for this complicated subset of patients. Further prospective studies must be performed before more definitive conclusions can be made.

Surgical Reconstruction to Allow Endovascular Access for Flow Diversion of Giant Cavernous Aneurysm: A Combined Approach

Giant cavernous aneurysms of the internal carotid artery (ICA) are challenging lesions associated with high surgical morbidity. Prior to the past several years, these were treated by surgical reconstruction, proximal ligation, or stent-assisted coiling techniques. Flow diversion has become the standard of care for these lesions, providing a high rate of obliteration with a much better safety profile. However, flow diverters rely upon a navigable vasculature and, usually, a tri-axial support system. Cases in which such access is difficult require unique approaches to combine the strengths of both surgical and endovascular therapy. A woman with a giant cavernous ICA aneurysm and an ophthalmic artery aneurysm presented for treatment, but access was challenging due to cervical ICA tortuosity and pseudoaneurysms. We elected a staged, combined approach with surgical reconstruction of the cervical ICA followed by flow diverter placement for the intracranial aneurysms. Our case features an “outside-the-box” approach that synergistically applied both microsurgical and endovascular techniques to treat a challenging pathology. Classic microsurgical techniques remain important in cases that are refractory or not amenable to endovascular therapy alone.

Blood Flow Diversion as a Primary Treatment Method for Ruptured Brain Aneurysms-Concerns, Controversy, and Future Directions

Flow diversion is a novel treatment for brain aneurysms that works by redirecting blood flow away from the aneurysm. Immediately after placement of the stent, blood flow stagnates within the aneurysm dome and it undergoes thrombosis. Over time, a new endothelium develops across the neck, thereby reconstructing the parent vessel and curing the aneurysm. The use of this treatment method for ruptured aneurysms has two specific concerns: 1) risk of hemorrhage from the aneurysm after treatment because of potential delayed aneurysm occlusion; and 2) hemorrhagic complications from antiplatelet use, which is required to prevent thromboembolic complications from the device. In this review, we explore these two concerns based on the emerging published literature. Optimal peri-procedural management of these issues in the neurocritical care setting is vital to improving outcomes. We also identify ongoing clinical trials of flow diversion for the treatment of ruptured aneurysms. Flow diversion is an alternative to clipping or coiling for many ruptured aneurysms and may be potentially more efficacious in certain aneurysm subtypes.

Experience using pipeline embolization device with Shield Technology in a patient lacking a full postoperative dual antiplatelet therapy regimen

Utilization of flow diverting devices is accompanied with dual antiplatelet therapy to reduce the risk of thromboembolic events, even though this increases the risk of hemorrhagic complications. The updated Pipeline Flex embolization device with Shield Technology has been created using a phosphorylcholine coating that reduces thrombogenicity and possibly reduces the need for dual antiplatelet therapy. However, because of the potential risk to patients of utilizing a pipeline embolization device without dual antiplatelet therapy, the pipeline embolization device with Shield Technology has not been tested in human subjects without dual antiplatelet therapy, and its contribution to preventing thromboembolic events is therefore unknown. We report a case in which a patient, following complications that limited his absorption of dual antiplatelet therapy, had low levels of dual antiplatelet therapy medications in his bloodstream following treatment for an intracranial aneurysm with a pipeline embolization device with Shield Technology. The patient recovered without signs of luminal stenosis or thromboembolic event.

Pipeline Embolization Device in Treatment of 50 Unruptured Large and Giant Aneurysms

INTRODUCTION

Treatment of large (≥20 mm) and giant (≥25 mm) intracranial aneurysms is challenging and can be associated with a high rate of morbidity and mortality. The Pipeline Embolization Device (PED) has been used effectively for the treatment of intracranial aneurysms achieving a high rate of complete occlusion. However, its safety and efficacy in treatment of large and giant aneurysms has not been evaluated fully.

METHODS

A retrospective analysis of consecutive aneurysms treated with PED between 2009 and 2016 at 3 academic institutions within the United States was performed. Large (≥20 mm) and giant aneurysms (≥25 mm) were selected for evaluation of occlusion and complication rates following treatment with PED.

RESULTS

A total of 50 large and giant aneurysms were individually treated using PED. Aneurysms were fusiform (74%) or saccular (26%) in morphology. PED alone was used for treating 78% of the aneurysms, whereas PED with adjunctive coiling was used for treating 22%. The median length of angiographic follow-up was 13 months (mean follow up 20.4 months). At last follow-up, complete or near-complete occlusion (90-100%) was achieved in 76.9% of aneurysms. Symptomatic thromboembolic complications were encountered in 12% of procedures and symptomatic hemorrhagic complications in 8%.

CONCLUSIONS

The use of PED for the treatment of large and giant intracranial aneurysms is associated with good occlusion rates, but also a greater complication rate compared to aneurysms of smaller size. There was no significant difference in occlusion rate based on aneurysm shape or size, number of PEDs placed, or adjunctive coiling.

Matched Comparison of Flow Diversion and Coiling in Small, Noncomplex Intracranial Aneurysms

BACKGROUND: Flow diversion is typically reserved for large, giant, or morphologically complex aneurysms. Coiling remains a first-line treatment for small, morphologically simple aneurysms.

OBJECTIVE: To compare coiling and flow diversion in small, uncomplicated intracranial aneurysms (typically amenable to coiling).

METHODS: Forty patients treated with the pipeline embolization device (PED) for small (&lt;10 mm), morphologically simple aneurysms that would have also been amenable to coiling were identified. These patients were matched in a 1:1 fashion with 40 patients with comparable aneurysms treated with coiling. Matching was based on age, gender, aneurysm size, and aneurysm morphology.

RESULTS: The 2 groups were comparable with regard to baseline characteristics including age, gender, and aneurysm size. The complication rate did not differ between the 2 groups (2.5% with coiling vs 5% with PED; P = .6). Multivariate analysis did not identify any predictor of complications. Complete occlusion (100%) at follow-up was significantly higher in patients treated with PED (70%) than coiling (47.5%, P = .04). In multivariate analysis, treatment with PED predicted aneurysm obliteration (P = .04). A significantly higher proportion of coiled patients (32.5%) required retreatment compared with flow diversion (5%, P = .003). In multivariate analysis, coiling predicted retreatment (P = .006). All patients achieved a favorable outcome (modified Rankin Scale: 0-2) regardless of group.

CONCLUSION: This matched analysis suggests that flow diversion provides higher occlusion rates, lower retreatment rates, and no additional morbidity compared with coiling in small, simple aneurysms amenable to both techniques. These results suggest a potential benefit for flow diversion over coiling even in small, uncomplicated aneurysms.

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis

BACKGROUND

Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear.

PURPOSE

To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices.

DATA SOURCES

Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion.

STUDY SELECTION

One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion.

DATA ANALYSIS

Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05).

DATA SYNTHESIS

Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001).

LIMITATIONS

Observational studies and case reports may be affected by reporting bias.

CONCLUSIONS

Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Evaluation of Pipeline Flex delivery system for the treatment of unruptured aneurysms

INTRODUCTION

Refinements in endovascular technology have revolutionized the treatment of intracranial aneurysms (IAs) with the development of flow-diversion technology. The first generation of the Pipelin Embolization Device (PED) has demonstrated its safety and efficacy. However, the deployment technique was a difficult task that often led to complex maneuvers. The Pipeline Flex Embolization Device (PED Flex) is the second generation and its introduction has arrived with high expectations due to a completely redesigned delivery system that intends to overcome deployment difficulties seen in the previous generation. Areas covered: Preclinical studies, mechanism of action of flow-diverters, technical aspects and deployment system of the PED Flex, and clinical outcomes with both PED generations. Expert commentary: Flow diversion has allowed us to treat lesions that would be otherwise challenging for surgical clipping or unsuitable for other endosaccular strategies. Although the experience with PED Flex is limited, initial results suggest its safety and short-term efficacy.

Carotid cavernous fistula after Pipeline placement: a single-center experience and review of the literature

Objective

Carotid cavernous fistula (CCF) development after Pipeline Embolization Device (PED) treatment of cavernous carotid aneurysms (CCA) can be a challenging pathology to treat for the neurointerventionalist.

Methods

A database of all patients whose aneurysms were treated with the PED since its approval by the Food and Drug Administration in 2011 was retrospectively reviewed. Demographic information, aneurysm characteristics, treatment technique, antiplatelet regimen, and follow-up data were collected. A literature review of all papers that describe PED treatment of CCA was then completed.

Results

A total of 44 patients with 45 CCAs were identified (38 women, 6 men). The mean age was 59.9±9.0 years. The mean maximal aneurysm diameter was 15.9±6.9 mm (mean neck 7.1±3.6 mm). A single PED was deployed in 32 patients, with two PEDs deployed in 10 patients and three PEDs in 3 patients. Adjunctive coiling was performed in 3 patients. Mean follow-up duration based on final imaging (MR angiography or digital subtraction angiography) was 14.1±12.2 months. Five patients (11.4%) developed CCFs in the post-procedural period after PED treatment, all within 2 weeks of device placement. These CCFs were treated with a balloon test occlusion followed by parent artery sacrifice. Our literature review yielded only three reports of CCFs after PED placement, with the largest series having a CCF rate of 2.3%.

Conclusions

CCF formation is a known risk of PED treatment of CCA. Although transvenous embolization can be used for treating CCFs, parent artery sacrifice remains a viable option on the basis of these data. Studies support the view that adjunctive coiling may have a protective effect against post-PED CCF formation. None of the coiled aneurysms in our database or in the literature have ruptured. Follow-up data will lead to a better understanding of the safety profile of the PED for CCA.