Predictors of the Effects of Flow Diversion in Very Large and Giant Aneurysms

Treatment outcomes and effectiveness of FRED for fusiform vertebral artery aneurysms

BackgroundAt our hospital, we use the flow re-direction endoluminal device (FRED) to treat vertebral artery (VA) aneurysms. Some reports suggest that the treatment efficacy of FRED may be lower in patients with fusiform-type aneurysms. At our hospital, we compared the treatment outcomes of FRED for both fusiform- and saccular-type aneurysms occurring at the posterior inferior cerebellar artery bifurcation.MethodsWe included 29 of 245 patients treated with FRED for VA aneurysms (9 saccular and 20 fusiform) between June 2020 and November 2022. We assessed occlusion rates and background factors, including age, sex, hypertension, diabetes, dyslipidemia, and smoking history. Patients received 100 mg aspirin and 3.75 mg prasugrel for at least 7 days prior to surgery. Non-responders received a loading dose of aspirin or prasugrel before surgery. Follow-up evaluations included magnetic resonance angiography (MRA) at 3 and 9 months and digital subtraction angiography (DSA) at 6 and 12 months. For patients with contradictions to DSA, MRI was used for follow-up if the aneurysm was visible. Additional FRED procedures were considered for patients with poor occlusion evidence at 6 months.ResultsPatients with fusiform type were younger (P = 0.025), and their aneurysms were larger (P = 0.036) and had better obliteration rates (P = 0.007), compared with the saccular type. In the fusiform group, 18 out of 20 cases (90%) achieved good obliteration, whereas only 2 out of 9 cases (34%) in the saccular group did. Multivariate analysis indicated that fusiform aneurysm type was a significant predictor of good obliteration.ConclusionsThe treatment effect of FRED on the fusiform VA aneurysm appears to differ from the outcomes based on the pipeline device, suggesting the potential for achieving favorable results earlier in fusiform cases.

Intraoperative aneurysm flow analysis predicts intracranial large and giant aneurysm occlusion after flow diversion

OBJECTIVES

Incompletely occluded flow-diverter (FD)-treated aneurysms are at risk of rupture and thromboembolic complications; however, intraoperative prediction of FD treatment outcomes has not yet been established. In this study, we investigated the association between intraoperative aneurysm flow analysis, using optical flow imaging, and FD treatment outcomes.

MATERIALS AND METHODS

This retrospective study included patients with large unruptured internal carotid artery aneurysms (≥ 10 mm) who underwent FD treatment. During the procedure, a flow analysis method using optical flow digital subtraction angiography (DSA) was used to measure the flow within the aneurysm sac by calculating the mean aneurysm flow amplitude (MAFA) before and after stent deployment. Occlusion was assessed using the O'Kelly-Marotta (OKM) grading scale on DSA 12 months after FD. The patients were divided into a nearly complete occlusion group (OKM grades C and D) and an incomplete occlusion group (OKM grades A and B).

RESULTS

Eleven patients with 11 aneurysms (mean age, 67.5 [standard deviation, 8.3] years; 10 women, 88.9 %) were treated with FD. Nearly complete occlusion was observed in 6/11 (54.5 %) patients at 12-month follow-up imaging. The nearly complete occlusion group had significantly lower pre-MAFA and post-MAFA values than the incomplete occlusion group (P = 0.023 and P = 0.008, respectively). There was no difference in the MAFA ratio between the two groups (P = 0.315) CONCLUSIONS: Aneurysm flow analysis before and after FD deployment is a simple and beneficial approach to predict treatment outcomes, which would indicate the need for intraoperative strategy changes, such as adding FD layers or intrasaccular coils.

Performance assessment of the Surpass Evolve flow diverter for the treatment of intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

The Surpass Evolve (SE) has emerged as a promising alternative treatment from the flow diverter series. The utilization of the SE has gradually increased, however, there is a scarcity of comprehensive data on the solidity of this technology in the endovascular treatment of intracranial aneurysms (IAs). This meta-analysis aimed to evaluate the safety and effectiveness of the SE flow diverter.

METHODS

A systematic literature search from inception to April 2024 was conducted across five databases for studies involving IAs treated with the SE. The primary effectiveness outcome was the proportion of complete aneurysm occlusion at the final follow-up, and the primary safety outcome comprised a composite of early and delayed complications. Subgroup analyses based on aneurysm size, anatomical location, and rupture status were also conducted.

RESULTS

Our analysis included nine studies with 645 patients and 722 IAs. Effectiveness outcomes revealed an overall complete aneurysm occlusion rate of 69% (95% confidence interval (CI) = 58%-78%; I2 = 72%) and a favorable aneurysm occlusion rate of 91% (95% CI = 82%-96%; I2 = 49%). Safety outcomes demonstrated an overall complications rate of 6% (95% CI = 3%-12%; I2 = 66%), with an early complications rate of 6% (95% CI = 4%-11%; I2 = 0%), and a delayed complications rate of 0% (95% CI = 0%-7%; I2 = 0%).

CONCLUSIONS

Our findings suggest a favorable outcome with a high rate of complete aneurysm occlusion at the last follow-up, with acceptable rates of neurological complications. Future research efforts should focus on larger, prospective studies with standardized outcome measures to further elucidate the clinical utility of the SE flow diverter in the management of IAs.

Flow Diversion for Cerebral Aneurysms: A Decade-Long Experience with Improved Outcomes and Predictors of Success

BACKGROUND

Flow diversion has significantly improved the management of cerebral aneurysms. Technological advancements and increased clinical experience over the past decade have led to better outcomes and fewer complications. This study provides updated results and examines the factors that influence the success of flow diversion.

METHODS

We reviewed records of 115 patients with 121 intracranial aneurysms treated from July 2014 to August 2023. All patients had unruptured aneurysms in the anterior and posterior circulation.

RESULTS

Complete aneurysm occlusion was achieved in 72.7% of cases, with a complication rate of 9.1%. Significant predictors of complete occlusion included aneurysm diameter (OR = 0.89, 95% CI 0.82-0.97, p = 0.009) and the presence of incorporated branches (OR = 0.22, 95% CI 0.08-0.59, p = 0.003). Cox analysis identified neck diameter (HR = 0.92, 95% CI 0.87-0.98, p = 0.009) and incorporated branch (HR = 0.40, 95% CI 0.24-0.69, p = 0.001) as significant for occlusion. Multivariable analysis identified aneurysm diameter (OR = 1.21, 95% CI 1.09-1.37, p = 0.001) as significant for safety outcomes. Improved outcomes were observed in recent treatments, with higher occlusion rates (79.7% vs. 61.7%, p = 0.050) and lower complication rates (4.1% vs. 14.9%, p = 0.011).

CONCLUSIONS

Enhanced technical proficiency, better devices, and refined patient selection have significantly improved the efficacy and safety of flow diversion for cerebral aneurysms. Identifying significant predictors for treatment success and safety outcomes can inform clinical practice, aiding in patient selection.

Prediction of obliteration of unruptured cerebral aneurysm by residual aneurysm volume after flow diverter stent treatment

Introduction There is no methodology to predict aneurysm occlusion using residual volume after flow diverter stent treatment. We retrospectively examined whether residual aneurysm volume at 6 months postoperatively can predict the degree of aneurysm obliteration at 1 year after flow diverter stent treatment. Materials and Methods This single institution study included 101 consecutive patients who underwent flow diverter stent treatment for unruptured cerebral aneurysm. Based on pre-treatment aneurysm volume, the percentage residual volume was calculated 6 months postoperatively. The volume of the aneurysm was determined using the volume calculation function of the cerebral angiography equipment. 1 year postoperatively, patients were classified into two groups: the good obliteration group (GG; O'KellyMarotta [OKM] grading scale: C and D) and the poor obliteration group (PG; OKM: A and B). Statistical analysis was performed to determine if there was a difference in residual aneurysm volume percentage at 6 months postoperatively between the two groups. Results A total of 20 patients were studied: 6 in the GG and 14 in the PG. Mean residual aneurysm volume at 6 months postoperatively in the GG was 33.1% (±34.7), while that in the PG was 80.6% (±24.8) (P=0.018). A residual aneurysm volume of ≥35.2% at 6 months postoperatively was significantly associated with poor aneurysm obliteration at 1 year postoperatively (AUC=0.88, P=0.008). Conclusions Residual aneurysm volume percentage at 6 months after flow diverter stent treatment might be able to predict the likelihood of aneurysm occlusion at 1 year postoperatively.

Treatment of giant intracranial aneurysms using the Pipeline flow-diverting stent: Long-term results from the International Retrospective Study of the Pipeline Embolization Device (IntrePED) study

BACKGROUND

Traditional endovascular treatments of giant intracranial aneurysms are associated with high rates of complications and retreatment. Our objective was to examine the safety and long-term efficacy of the Pipeline Embolization Device for treatment of these aneurysms.

METHODS

This retrospective study using the IntrePED database included all patients with giant intracranial aneurysms treated with the Pipeline device between July 2008 and February 2013. Efficacy outcomes were stratified by using the Raymond-Roy Occlusion Classification. Predefined safety outcomes included spontaneous rupture of the target aneurysm; ipsilateral intracranial hemorrhage; ischemic stroke; parent artery stenosis; and sustained cranial neuropathy.

RESULTS

Sixty-six embolizations were performed to treat 63 giant intracranial aneurysms (including 2 ruptured): 49 (77.8%) in the anterior and 14 (22.2%) in the posterior circulation. The median follow-up was 22.4 (0.1-60.5) months. Class I angiographic occlusion was achieved in 72.0% (36/50). The neurological morbidity/mortality rate was 23.8% (15/63), with higher rates in the posterior circulation than in the anterior circulation (22.4% vs. 28.6%). Among seven deaths, five had neurological causes. The procedure-related neurological morbidity and mortality rates were 22.7% (15/66) and 7.6% (5/66), respectively. The spontaneous rupture rate was 4.5% (3/66). Two spontaneous ruptures (1 death), 4/4 postprocedural intracranial hemorrhages, and 6/9 ischemic events occurred within 30 days. In-stent stenosis and new-onset cranial neuropathy were not observed during the angiographic follow-up period.

CONCLUSIONS

Although procedure-related neurological morbidity/mortality rates were not insignificant, this study confirms the feasibility and long-term efficacy of the Pipeline Embolization Device to treat giant intracranial aneurysms.

Safety and efficacy of Surpass Evolve Flow diverter for intracranial aneurysms: A study of 116 patients

BACKGROUND AND PURPOSE

Flow diverter embolization is a recognized method for treating intracranial aneurysms. This study evaluates the safety and efficacy of the Surpass Evolve flow diverter in treating intracranial aneurysm.

MATERIAL AND METHODS

From May 2019 to June 2022, our center prospectively enrolled patients presenting with both ruptured and unruptured intracranial aneurysms. We assessed aneurysm occlusion, along with the occurrence of ischemic and hemorrhagic complications, and mortality at 6-months. The 3-month occlusion rate was determined using MR angiography, while the 6-month occlusion rate employed the O'Kelly-Marotta (OKM) grading scale on DSA.

RESULTS

A total of 116 patients with 120 aneurysms received treatment with the Surpass Evolve device. The average aneurysm size was 6.6 mm (range: 2-30 mm). All patients were administered two loading doses of ticagrelor (180 mg) one day before the procedure and 2 h pre-embolization. A procedural complication occurred in one case, involving wire-related perforation of an M3 branch distant from the giant aneurysm; however, this evolved favorably. There were no reported deaths linked to the treatment. Permanent neurological deficits were observed in 3 (2.5%) patients, primarily due to early in-stent thrombosis. MR angiography results at 3 months indicated complete occlusion for 87 out of 115 (75.6%) monitored aneurysms. The 6-month DSA showed neck remnant or complete occlusion (OKM grade C or D) in 86 out of the 107 (80.4%) patients who underwent follow-up.

CONCLUSION

The Surpass Evolve stands out as a reliable and effective flow diverter for the management of intracranial aneurysms.

Evaluation of the Significance of Persistent Remnant Filling and Enlargement After Flow Diversion for Intracranial Aneurysms

BACKGROUND

This study aimed to evaluate the clinical course after flow diversion (FD) treatment with a focus on aneurysms with remnant sac filling, by analyzing angiographic outcomes, aneurysm volume, and clinical events.

METHODS

We retrospectively reviewed the medical records of 61 patients who underwent FD for intracranial aneurysms between July 2014 and June 2021.

RESULTS

The majority of aneurysms (52.5%) were located in the internal carotid artery, with a median diameter of 16.6 mm and neck size of 9.3 mm. Remnant filling was observed in 17 aneurysms (27.9%) more than 18 months after FD, 10 (16.4%) of these aneurysms underwent enlargement, which occurred only in cases with subtotal filling or entry remnant states. Eleven patients experienced major adverse events, and three exhibited unfavorable functional outcomes. The incidence of major adverse events and unfavorable functional outcomes was significantly higher in the aneurysm enlargement group than that in the no-filling or stable remnant filling groups (P < 0.001). Aneurysmal diameter and the presence of incorporated branches were independent predictors of aneurysm enlargement, while the presence of incorporated branches was the only independent predictor of persistent remnant filling.

CONCLUSIONS

Aneurysm enlargement after FD is not uncommon, particularly when the aneurysm is large, has incorporated vessels, or does not undergo occlusion within 12 months, often culminating in major adverse events and unfavorable functional outcomes. In addition to investigating angiographic results, it is necessary to evaluate the changes in aneurysm size and clinical events when assessing the efficacy of FD.

Parent artery occlusion after pipeline embolization device implantation of intracranial saccular and fusiform aneurysms

BACKGROUND

Studies reporting parent artery occlusion (PAO) after pipeline embolization device (PED) implantation are limited. The aim of this study was to investigate the incidence rate and risk factors of PAO after PED implantation.

METHODS

In this retrospective study, we enrolled consecutive patients with intracranial saccular and fusiform aneurysms treated with PED implantation at our institution. Multivariate logistic regression analysis was subsequently performed to determine the risk factors for PAO.

RESULTS

A total of 588 saccular and fusiform aneurysms were finally enrolled in the study. PAO was found in 14 (2.38%) aneurysms. The aneurysm complete occlusion rate was 79.6%. Compared with the non-PAO group, aneurysms in the PAO group were larger in size (20.08 vs 9.61 mm; p<0.001), had a greater neck diameter (9.92 vs 6.15 mm; p=0.001), and had higher frequencies of adjunctive coils (64.3% vs 35.7%; p=0.028). In the multivariate logistic analysis, aneurysm size (OR 1.12, 95% CI 1.02 to 1.24; p=0.016) and the presence of poor wall apposition after balloon angioplasty (OR 7.74, 95% CI 1.28 to 46.82; p=0.026) were associated with PAO occurrence after adjusting for confounding factors.

CONCLUSIONS

In this study, the incidence rate of PAO following PED implantation was 2.38% in intracranial saccular and fusiform aneurysms. Aneurysm size and residual presence of poor wall apposition after balloon angioplasty were risk factors for PAO. Further research is required to better understand the mechanisms of PAO.

Treatment Outcomes of 94 Cases of Pipeline Embolization Device in a Single Center: Predictive Factors of Incomplete Aneurysm Occlusion

Objective

This study aimed to report the outcome of an endovascular treatment with a pipeline embolization device (PED) at a single center. We also examined the predictive factors for an incomplete occlusion after the PED placement.

Methods

The subjects were 94 patients with 109 aneurysms who underwent the PED placement at our single center from June 2015 to September 2022. As treatment outcomes, we investigated the PED placement success rate, perioperative morbidity and mortality, postoperative cranial nerve improvement rate, and the classification of angiographic result at 6 months after the PED placement. Furthermore, the predictors of an incomplete occlusion were investigated in detail.

Results

One hundred nine aneurysms locations were: C1 (9), C2 (30), C3 (15), C4 (53), and C5 (2) in the internal carotid artery segments. Perioperative morbidity, including the asymptomatic ones, occurred in 10 cases (10.6%). Among these 10 cases, the modified Rankin Scale (mRS) improved to preoperative mRS after 90 days in 9 cases except 1 case. On the other hand, no perioperative mortality was observed. The postoperative cranial nerve improvement rate was 84.4%, and 61.7% of patients had a complete occlusion in the follow-up angiography, 6 months after the PED placement. Predictive factors for an incomplete occlusion after the PED placement were the elderly aged 70 years or older (P-value = 0.0214), the elderly aged 75 years or older (P-value = 0.0009), and the use of anticoagulants (P-value = 0.0388) in an univariate analysis. Further, the multivariate analysis revealed that the elderly aged 75 years or older was a predictive factor of an incomplete occlusion in this study.

Conclusion

We summarized the outcomes of the PED treatment at our single center. In this study, the elderly aged 75 years or older was a predictive factor of an incomplete occlusion after the PED placement.