Multiple Pipeline Embolization Devices for the Treatment of Complex Intracranial Aneurysm: A Multi-Center Study

Intracranial hemorrhagic events associated with flow diversion treatment: a retrospective analysis from a single academic institution

Intracranial hemorrhages are highly concerning but underreported complications related to flow diversion (FD) treatment of intracranial aneurysms. Herein, we aimed to characterize these complications and the factors influencing their occurrence. We retrospectively reviewed patients treated with FD from 2013 to 2023 at a single U.S. institution, analyzing aneurysm characteristics, comorbidities, antiplatelet and anticoagulation use, and hemorrhage imaging features. Risk factors for intraparenchymal hemorrhages (IPHs) were assessed with univariate analysis. There were 622 patients harboring 788 aneurysms treated in 690 procedures during the study period. Within 7 months of follow-up, 15 intracranial hemorrhages were identified (2.2%): 2 acute subdural hematomas (SDH), 7 IPH, 1 intraventricular hemorrhage (IVH), and 5 subarachnoid hemorrhages (SAH), most of which presented within the first 24 h after initial treatment. Patients experiencing hemorrhages exhibited lower rates of functional independence (mRS ≤ 2) compared to those without hemorrhage (66.7% vs. 93.3%; p < 0.01). IPHs were slightly higher in patients receiving aspirin-ticagrelor (1.2%) compared to those on aspirin-clopidogrel (0.9%) or aspirin-prasugrel (0.0%). A univariate logistic regression model demonstrated an aneurysmal diameter ≥ 12 mm (OR = 8.98; 95% CI = 1.98-16.03) and aneurysms with prior treatment (OR = 7.20; 95% CI = 1.59-32.60) as factors influencing IPHs after treatment. The incidence of hemorrhage decreased over the time interval of study. Intracranial hemorrhages related to FD are rare but highly morbid complications. Treatments involving larger aneurysms and those with prior interventions are associated with a higher risk of IPHs.

Flow diversion for the treatment of intracranial bifurcation aneurysms: a systematic review and meta-analysis

BACKGROUND

Flow diversion (FD: flow diversion, flow diverter) is an endovascular treatment for many intracranial aneurysm types; however, limited reports have explored the use of FDs in bifurcation aneurysm management. We analyzed the safety and efficacy of FD for the management of intracranial bifurcation aneurysms.

METHODS

A systematic review identified original research articles that used FD for treating intracranial bifurcation aneurysms. Articles with >4 patients that reported outcomes on the use of FDs for the management of bifurcation aneurysms along the anterior communicating artery (AComA), internal carotid artery terminus (ICAt), basilar apex (BA), or middle cerebral artery bifurcation (MCAb) were included. Meta-analysis was performed using a random effects model.

RESULTS

19 studies were included with 522 patients harboring 534 bifurcation aneurysms (mean size 9 mm, 78% unruptured). Complete aneurysmal occlusion rate was 68% (95% CI 58.7% to 76.1%, I2=67%) at mean angiographic follow-up of 16 months. Subgroup analysis of FD as a standalone treatment estimated a complete occlusion rate of 69% (95% CI 50% to 83%, I2=38%). The total complication rate was 22% (95% CI 16.7% to 28.6%, I2=51%), largely due to an ischemic complication rate of 16% (95% CI 10.8% to 21.9%, I2=55%). The etiologies of ischemic complications were largely due to jailed artery hypoperfusion (47%) and in-stent thrombosis (38%). 7% of patients suffered permanent symptomatic complications (95% CI 4.5% to 9.8%, I2=6%).

CONCLUSION

FD treatment of bifurcation aneurysms has a modest efficacy and relatively unfavorable safety profile. Proceduralists may consider reserving FD as a treatment option if no other surgical or endovascular therapy is deemed feasible.

Complex intracranial aneurysms: a DELPHI study to define associated characteristics

PURPOSE

Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA.

METHODS

An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability.

RESULTS

In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac.

CONCLUSIONS

The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach.

Comparison of pipeline embolization device and tubridge flow diverter for posterior circulation aneurysms: A multicentre propensity score matched study

Rationale and objectives

The off-label use of flow diverters (FDs) has broadened to include treating aneurysms in posterior circulation (PC). A novel flow diverter, the Tubridge flow diverter (TFD), has been created in China specifically for treating PC aneurysms. However, studies comparing between pipeline embolization device (PED) and TFD are rare. Thus, our study aimed to explore the effectiveness of PED and TFD in the treatment of PC aneurysms using a propensity score matched cohort design.

Methods

Retrospective data collection was conducted on patients who underwent treatment with either PED or TFD over the period from 2015 through 2020. Propensity score matching (PSM) was employed to calibrate for patient age; history of ischemic stroke; aneurysm size; morphology; location and neck; number of FDs; parent vessel diameter; and the employment of assisted coiling and balloon techniques. Data on previously ruptured aneurysms was not included in the analysis. A comparison was conducted between the two devices to assess perioperative complications, aneurysm occlusion rates, and functional outcomes.

Results

A total of 252 PC aneurysms were treated in 248 patients. Clinical and imaging follow-ups were lost in 26 and 47 patients, respectively. Major perioperative complications occurred in 7.5% of the cases, with favorable clinical outcomes in 91.0% and complete occlusion in 79.1%. Eighty-two (32.5%) aneurysms were treated with TFD, while 170 (67.5%) aneurysms were treated with PED. PSM was used to account for these significant variations, producing 82 matched pairs of unruptured aneurysms treated with PED or TFD. In terms of functional and angiographic outcomes, no significant differences were found between PED and TFD (functional outcome, p = 0.594 and angiographic outcome, p = 0.415). However, more perioperative major complications were found in patients treated with TFD (p = 0.005) compared with those receiving PED.

Conclusion

The comparative study of PED and TFD in the treatment of PC aneurysms resulted in positive clinical results and sustained occlusion rates, with acceptable perioperative complications. However, higher quality studies are needed to enhance our understanding of the use of FDs for treating of PC aneurysms.

Visualization balloon occlusion-assisted technique in the treatment of large or giant paraclinoid aneurysms: A study of 17 cases series

Objective

Although balloon-assisted techniques are valuable in aneurysm clipping, repeated angiography and fluoroscopy are required to understand the location and shape of the balloon. This study investigated the value of visualization balloon occlusion-assisted techniques in aneurysm hybridization procedures.

Methods

We propose a visualization balloon technique that injects methylene blue into the balloon, allowing it to be well visualized under a microscope without repeated angiography. This study retrospects the medical records of 17 large or giant paraclinoid aneurysms treated by a visualization balloon occlusion-assisted technique in a hybrid operating room. Intraoperative surgical techniques, postoperative complications, and immediate and long-term angiographic findings are highlighted.

Results

All 17 patients had safe and successful aneurysm clipping surgery with complete angiographic occlusion. Under the microscope, the balloon injected with methylene blue is visible through the arterial wall. The position and shape of the balloon can be monitored in real time without repeated angiography and fluoroscopic guidance. Two cases of intraoperative visualization balloon shift and slip into the aneurysm cavity were detected in time, and there were no cases of balloon misclipping or difficult removal. Of 17 patients, four patients (23.5%) experienced short-term complications, including pulmonary infection (11.8%), abducens nerve paralysis (5.9%), and thalamus hemorrhage (5.9%). The rate of vision recovery among patients with previous visual deficits was 70% (7 of 10 patients). The mean follow-up duration was 32.76 months. No aneurysms or neurological deficits recurred among all patients who completed the follow-up.

Conclusion

Our study indicates that microsurgical clipping with the visualization balloon occlusion-assisted technique seems to be a safe and effective method for patients with large or giant paraclinoid aneurysms to reduce the surgical difficulty and simplify the operation process of microsurgical treatment alone.