Received: Wed 23, Apr 2025
Accepted: Wed 21, May 2025
Abstract
The Woven EndoBridge (WEB) device has gained popularity for treating wide-necked aneurysms, demonstrating safety and efficacy. This case report presents diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and clinical data for an adult woman who underwent WEB treatment for an unruptured anterior communicating artery aneurysm. An adult female patient developed right-sided limb weakness after treatment for an anterior communicating artery aneurysm using the WEB device. DWI and SWI revealed micro-embolisms and microbleeds in the left hemisphere. Following treatment with antiplatelet medication, the patient’s muscle strength returned to normal. Six months later, follow-up DWI and SWI indicated that the micro-embolisms had disappeared. DWI combined with SWI is highly sensitive for detecting micro-embolisms and microbleeds, proving crucial for identifying postoperative complications associated with WEB devices. Further large-scale prospective studies are needed to define better the optimal antiplatelet regimen for managing intracranial aneurysms with WEB devices.
Keywords
WEB device, diffusion-weighted imaging, susceptibility-weighted imaging, case report
1. Background and Importance
Microstroke events are serious complications that can arise during embolization treatment for intracranial aneurysms (IAs), potentially resulting in permanent neurological disability or even death [1, 2]. Over time, the Woven EndoBridge (WEB) device has gained widespread acceptance for treatment of IAs [3, 4]. Previous studies have emphasized the importance of diffusion weighted imaging (DWI) in detecting micro-embolism following endovascular treatment for IAs [5]. Additionally, susceptibility weighted imaging (SWI) is highly sensitive in detecting deoxyhemoglobin in cerebral microbleeds, and its application has significantly expanded [2]. However, there are currently no reports documenting postoperative DWI micro-embolism or SWI microbleeds associated with the use of WEB devices in endovascular treatment. In this report, we present imaging findings and case data from a patient with an unruptured anterior communicating artery (ACA) aneurysm who underwent endovascular treatment with a WEB device, which demonstrated positive results on both DWI and SWI.
2. Clinical Presentation
An adult female patient was admitted to the Department of Neurosurgery with the chief complaint of an anterior communicating artery (ACA) aneurysm persisting for over one month. Neurological examination revealed a Glasgow Coma Scale (GCS) score of 15 and a modified Rankin Scale (mRS) score of 0, and no significant abnormal findings. The patient's medical and family histories were unremarkable. Preoperative imaging, including head computer tomography angiography (CTA) and digital subtraction angiography (DSA), confirmed the presence of an unruptured ACA aneurysm (ovoid, 6.11 mm × 4.43 mm, neck 3.91 mm) (Figures 1A-1C). Laboratory examinations showed no abnormalities. Consequently, a WEB device (SL 5 × 3 mm, MicroVention, USA) was successfully implanted.
Postoperative imaging confirmed the successful placement of the WEB, demonstrating contrast retention within the aneurysm and normal flow in the parent artery and distal blood vessels (Figure 1D). On the night following the WEB device placement, the patient maintained a GCS score of 15 and an mRS score of 0. However, on the second postoperative day, the patient reported weakness in the right lower extremity. Examination indicated muscle strength of grade 3 in the right lower limb, while the GCS remained 15 and the mRS increased to 4. On the same day, head CT showed no significant abnormalities, while DWI and SWI showed several micro-embolisms and microbleeds in the left hemisphere (Figures 1E-1G). Postoperatively, the patient was treated with dual antiplatelet therapy (aspirin 100 mg daily and ticagrelor 90 mg twice daily) and began rehabilitation.
By the third postoperative day, the patient's right lower limb strength gradually improved, and she was discharged in good condition on the fifth day after surgery. Six months postoperatively, follow-up DWI and SWI scans demonstrated that the micro-embolisms and microbleeds in the left middle cerebral hemisphere had disappeared (Figures 1H-1I). This case report was approved by the patient, and all identifying information was anonymized.
3. Discussion
One of the most serious complications in the endovascular treatment of IA is perioperative thromboembolism [5]. The incidence of micro-embolism events following endovascular treatment of IAs has been reported to be high, with risk factors including older age, dyslipidemia, diabetes mellitus, previous ischemic stroke, white matter lesions, aneurysm rupture, multiple aneurysms, larger necks of aneurysms, and prolonged duration [6]. Previous studies have shown that DWI is effective for visualizing micro-embolic lesions [5-7]. For instance, Kang DH et al. reported that the number of DWI-positive lesions in patients with symptomatic ischemic stroke was significantly higher compared to asymptomatic patients.
Notably, individuals aged 65 and older exhibited a trend toward increased risk of symptomatic ischemic stroke postoperatively, identifying older age as an independent risk factor predictive of DWI-positive findings indicating postoperative ischemic stroke [5]. Additionally, Iosif C et al. noted that DWI lesions related to surgical procedures often present asymptomatically. Regardless of the endovascular techniques employed, these lesions do not appear to correlate significantly correlate with surgical complications or adversely affect clinical outcomes [8]. Furthermore, Tokunaga K et al. found that in the endovascular treatment of unruptured IAs, older age, the use of flow-diverting (FD) stents, and longer procedure times were associated with postoperative DWI-positive lesions [6].
In 2024, Rodriguez-Erazú F et al. reported a total of 35 thromboembolic events among 266 patients treated with WEB devices; among these, 23 were intraoperative thromboembolic events and 12 were postoperative thromboembolic events, with 16 cases classified as symptomatic thromboembolic events [9]. It is important to note that postoperative thromboembolic in the context of WEB device reports is defined as any new neurologic deficit that develops within three months of the procedure, following thrombus formation in the arterial lumen during WEB embolization. However, these reports did not include imaging assessments using DWI, which may have led to the underreporting of many asymptomatic thromboembolic lesions [9]. In this case, the patient developed right-sided limb weakness, which was initially attributed to microembolisms and microbleeds seen on DWI and SWI. However, it is essential to consider alternative causes for the observed symptoms. Delayed thromboembolism, unrelated to the WEB device, remains a plausible differential diagnosis. Thromboembolic events can occur in the setting of any endovascular intervention and might not always be directly related to the device used. These events can be attributed to factors such as vessel injury, manipulation of the artery during the procedure, or the formation of thrombus in the parent artery or distal vessels.
Studies have reported the occurrence of microbleeds following aneurysm surgery, which may be associated with variety factors. SWI is a combination of specialized sequences and processing techniques designed to enhance contrast in T2-weighted images. Initially developed to visualize deoxyhemoglobin in veins and cerebral microbleeds, SWI's applications have since expanded significantly [2]. Previous studies have suggested that using SWI to evaluate intracerebral microbleeds may assist in predicting the condition of infective endocarditis in patients [10]. For example, King RM et al. found a significant difference in the average number of SWI-positive lesions between the uncoated and coated flow-diverting (FD) stent groups during a one-week follow-up [11]. In this report, the patient showed SWI-positive lesions postoperatively. However, based on the patient's clinical presentation, these lesions were not currently considered responsible for the patient's limb weakness. However, it is important to acknowledge that both DWI and SWI have certain limitations in postoperative interpretation. These imaging modalities may not always detect subtle or asymptomatic lesions, and their sensitivity can be influenced by factors such as the timing of the scan post-surgery and other underlying patient conditions.
The placement of the WEB device into the aneurysm cavity, much like spring coil embolization, raises ongoing controversies regarding the optimal antiplatelet regimen for treating IAs. In 2013, Spelle and Liebig recommended administering preoperative aspirin at a dosage of 100 mg per day for 3 to 5 days when using the WEB device, suggesting that continuation of antiplatelet therapy postoperatively is unnecessary [12]. However, Pierot L et al. observed a statistically significant difference in the incidence of thromboembolic events between patients receiving one or two antiplatelet medications and those not receiving any antiplatelet therapy when treated with the WEB device [13]. Some centers currently refrain from using preoperative antiplatelet therapy with WEB devices, a practice that may influence the occurrence of micro-embolism post-treatment and warrants further investigation in large prospective studies.
A retrospective review of patient data at our hospital undergoing WEB treatment for IAs revealed that most were treated with antiplatelet drugs, which were discontinued one month postoperatively, and had non-experienced clinical complications during the one-month follow-up period. Nevertheless, further studies are essential to evaluate the role of antiplatelet therapy in WEB treatment for IAs. Additionally, we are in the process of registering a prospective study aimed at to identifying the risk factors and developing clinical prediction models for micro-embolism and microbleed following WEB device treatment. In conclusion, while this case provides valuable insights, it is important to note that it does not yet have broad applicability, and further prospective studies are needed to explore and validate these findings in a larger patient population.
4. Conclusion
We are reporting the case of positive DWI and SWI following WEB treatment for an IA. While the therapeutic efficacy of the WEB device for IA is well established, concerns regarding associated complications persist. The combination of DWI and SWI is highly sensitive in detecting micro-embolisms and microbleeds, making it a crucial tool for identifying postoperative complications related to the use of WEB devices. To optimize patient management, further large-scale prospective studies are necessary to better define the ideal antiplatelet regimen for patients undergoing IA treatment with WEB devices.
Disclosures
The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
Ethics Approval and Consent to Participate
This case report does not include specific patient information and was published with the consent and notification of the patient and all authors.
Consent for Publication
This case report does not include specific patient information and was published with the consent and with the informed consent of the patient and all authors.
Availability of Data and Materials
Not applicable.
Competing Interests
None.
Funding
This study was supported by the National Natural Science Foundation of China (No. 81571202), Clinical Research 5010 Program of Sun Yat-Sen University (No. 2021001), the "five-five" project construction project of the Third Hospital of Sun Yat-sen University (2023WW504), Clinical High-tech Projects in Guangzhou Area (20247-GX30), 2023 Guangdong Provincial Natural Science Foundation General Project (2024A1515012906), National Administration of Traditional Chinese Medicine Foundation of China (No. CXZH202404015), Clinical Research Programme, the Fundamental Research Funds for the The Eighth Affiliated Hospital, Sun Yat-sen University (No. 5).
Acknowledgements
We acknowledge the patient for allowing us the permission to share this rare case.
Author Contributions
Hui Wang and Chuan Chen contributed to provide this case. Li-Xin Huang, Tao Sun, Jun Sun, and Zhi-Min Wu wrote the main manuscript text and prepared figures. All authors participated in the interpretation and collection of the data. All authors reviewed the manuscript.
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