Flow Diverter Treatment of Ruptured Basilar Artery Perforator Aneurysms: A Multicenter Experience

Treatment of ruptured intracranial aneurysms with parent artery flow diverter devices: A comprehensive systematic review and meta-analysis

BACKGROUND

Surgical clipping and endovascular coiling are well-established treatments for acutely ruptured intracranial aneurysms leading to acute subarachnoid hemorrhage (aSAH). However, these modalities have limitations, particularly in cases involving wide-necked, bifurcating, or dissecting aneurysms. Flow diverter (FD) devices, initially used for unruptured aneurysms, have emerged as an alternative treatment for ruptured aneurysms despite concerns about hemorrhagic complications.

AIMS

This study aimed to perform a comprehensive systematic review and meta-analysis to assess the efficacy and safety of parental artery FD devices in treating ruptured intracranial aneurysms.

METHODS

A systematic search was conducted in Medline, Embase, and Cochrane databases from inception to July 2024. The inclusion criteria focused on studies involving patients with acutely ruptured aneurysms treated with parental artery FDs, with or without adjunctive coiling. Studies were required to report clear, stratified data specific to the population of interest, and include more than five patients. Exclusion criteria included studies on non-ruptured aneurysms, intrasaccular flow diversion devices, or previously clipped aneurysms treated with FD. Data extraction was performed independently by two authors, and statistical analysis included single proportion analysis with 95% confidence intervals under a random-effects model, using R Studio. The primary outcome was the rate of aneurysm occlusion at follow-up.

SUMMARY OF REVIEW

A total of 60 studies encompassing 1300 patients were included. The primary outcome analysis revealed a 90% (95% CI: 87-92%; I2 = 51%) rate of total occlusion at follow-up. Subgroup analysis indicated an occlusion rate of 89% for anterior circulation aneurysms and 96% for posterior circulation aneurysms. Intraoperative complications occurred in 6% of cases, while postoperative complications were observed in 13%. Rebleeding rates were low at 1%, with a 2% need for retreatment. Good functional outcomes (mRS ⩽ 2) were achieved in 82% of patients, and the overall mortality rate was 4%.

CONCLUSIONS

FD devices demonstrated high rates of aneurysm occlusion and favorable functional outcomes in patients with acutely ruptured intracranial aneurysms. However, the low mortality rate and favorable outcomes observed may reflect selection bias toward patients with less severe SAH. Despite a modest complication rate, the overall safety and efficacy of FD devices suggest they may be a viable alternative to traditional treatments for specific aneurysm types. Further studies, including a broader spectrum of SAH severities, are warranted to optimize their use in clinical practice.

Benign versus sinister aetiologies underlying basal cistern subarachnoid haemorrhage: a case series

BACKGROUND

Subarachnoid hemorrhage in the basal cisterns is usually identified on an unenhanced computed tomography scan of the head in patients presenting acutely with a characteristic sudden onset headache.

CASE PRESENTATION

Using imaging examples from our tertiary neurosciences center, we present six cases demonstrating a variety of causes for subarachnoid hemorrhage in the basal cisterns, ranging from benign to sinister causes. These include a venous perimesencephalic hemorrhage (35 years, female), pontine perforator aneurysm (54 years, male), vertebral artery dissection (69 years, male), cervical dural arteriovenous fistula (65 years, male), posterior fossa arteriovenous malformation (45 years, male), and vertebral artery aneurysm (78 years, female). Ethnically, all these patients were white. Specific imaging features are described and demonstrated.

CONCLUSION

A balance between avoiding excessive investigation and overlooking what may be a mimic of a venous perimesencephalic hemorrhage is important. To refine and establish more definitive indications on when to perform computed tomography angiogram, digital subtraction angiography, delayed angiography and magnetic resonance imaging in this context requires future research to focus on large-scale prospective multicenter studies with robust data.

Open Microsurgical Versus Endovascular Management of Unruptured and Ruptured Brain Aneurysms

Open microsurgical and endovascular techniques are the 2 primary strategies for treating intracranial aneurysms. Microsurgical clipping and adjuvant technical maneuvers are well-established techniques with a track record for high occlusion rates and durable repairs. Endovascular, endosaccular, and extrasaccular therapies are associated with lower peri-procedural morbidity but with generally higher rates of retreatment. We discuss key clinical and anatomic considerations in treatment decision-making and compare the risks and benefits of microsurgical vs endovascular treatment within each context.

Neuroanatomy of the vertebrobasilar perforators: implications for aneurysm treatment

The anatomy of vertebrobasilar perforators has been widely studied in human cadavers, with most reports found in the neurosurgical literature. These arterial perforators are extremely hard to visualize consistently with traditional two-dimensional digital subtraction angiography, but are reliably visible with cross sectional cone beam CT techniques. A clear understanding of this specific neurovascular anatomy and pathology is essential for informed treatment decisions. This review analyzes the anatomy of vertebrobasilar perforators with a focus on practical implications for aneurysm treatment, particularly flow diversion.

Current research status and future of endovascular treatment for basilar artery aneurysms

Aneurysms occurring along the basilar artery (BA) account for <1% of all intracranial aneurysms. Endovascular treatment (EVT) in particular is recommended for large unruptured BA aneurysms and ruptured BA aneurysms. Given that EVT techniques vary, a detailed review of EVT for BA aneurysms is necessary. In this review, the following issues were discussed: the anatomy and anomalies of the BA, the classification of BA aneurysms, the natural history of BA aneurysms, the status of open surgery, the use of EVT for various types of BA aneurysms and the deployment of new devices. According to the findings of this review and based on our experience in treating BA aneurysms, traditional coiling EVT is still the optimal therapy for most BA aneurysms. However, in some BA aneurysms, flow diverter (FD) deployment can be used. In addition, there are also some new devices, such as intrasaccular flow disruptors and stent-like devices that can be used to treat BA aneurysms. In general, EVT can yield good clinical and angiographic outcomes for patients with BA aneurysms. In addition, recent new devices and techniques, such as new-generation FDs generated via surface modification and virtual reality simulation techniques, show promise for EVT for BA aneurysms. These devices and techniques may further improve EVT outcomes for BA aneurysms.

Two Cases of Subarachnoid Hemorrhage with Microaneurysmal Changes and Spontaneous Disappearance in the Basilar Artery

A 79-year-old woman presented at our hospital with sudden headache and vomiting. Computed tomography revealed diffuse subarachnoid hemorrhage. Although digital subtraction angiography (DSA) performed on admission and on the following day revealed no vascular abnormalities, DSA on Day 22 revealed microaneurysmal changes in the dorsal basilar artery. However, the aneurysmal changes gradually became smaller during follow-up, and DSA on Day 73 revealed complete disappearance. A 53-year-old man also presented to our hospital with sudden headache and vomiting. Computed tomography revealed perimesencephalic subarachnoid hemorrhage. DSA on Days 9 and 16 revealed microaneurysmal changes in the dorsal basilar artery. Conservative treatment was continued, and DSA on Day 42 revealed spontaneous disappearance of the lesion. It has been reported that basilar artery perforating aneurysms cause angiogram-negative subarachnoid hemorrhage, which disappears spontaneously. The fact that lesions previously reported as basilar artery perforating aneurysms may include cases of acute dissection of the main trunk or perforating branches of the basilar artery implies that surgical or endovascular treatment may worsen the condition. Therefore, conservative treatment may be an important option.

An unusual etiology of subarachnoid hemorrhage, basilar artery perforator aneurysms, in Macao: Three case reports and review of literature

BACKGROUND

Subarachnoid hemorrhage is a severe neurological condition that requires prompt and appropriate treatment to prevent complications. Aneurysms are the most common cause of spontaneous subarachnoid hemorrhage. Conversely, basilar artery perforator aneurysms (BAPAs) are a rare etiology. There is no consensus on the optimal management of ruptured BAPAs in the acute setting.

CASE SUMMARY

We present a case series of 3 patients with ruptured BAPAs who were treated at our institution. Two patients had a modified Fisher grade of I, and one had a grade of IV on initial presentation. The aneurysms were detected by computed tomography angiography in two cases and conventional angiography in one case. The 3 patients underwent endovascular treatment with Guglielmi detachable coils. Post-treatment, the patients had good clinical outcomes, and follow-up brain computed tomography scans showed reduced subarachnoid hemorrhage without any new hemorrhage. However, one patient experienced a cerebral infarction 2 months later and eventually succumbed to the condition. The other 2 patients showed progressive recovery, and no aneurysm recurrence was observed at the 2-year follow-up.

CONCLUSION

Endovascular treatment may be a preferable approach for managing ruptured BAPAs compared with surgical intervention or conservative management. Early detection and prompt treatment is important to achieve favorable patient outcomes.

Basilar artery perforator aneurysms: a comparison with non-perforator saccular aneurysms

BACKGROUND

Basilar artery perforator aneurysms (BAPAs) are rare. There is no systematic description of their presentation, imaging, natural history and outcomes and how these compare to conventional non-perforator aneurysms. Thus, the authors in this study aimed to compare BAPAs to non-perforator aneurysms.

METHODS

Cases were identified from a prospective neurovascular database, notes and imaging retrospectively reviewed and compared to a consecutive series of patients with non-perforator aneurysms. Blood volume on CT and vessel wall imaging (VWI) were compared to controls.

RESULTS

9/739 patients with aneurysmal subarachnoid haemorrhage (aSAH) harboured BAPAs. Compared to 103 with aSAH from posterior circulation aneurysms, they were more likely to be male (6/9, p = 0.008), but of equal severity (4/9 poor grade, p = 0.736) and need of CSF drainage (5/9, p = 0.154). Blood volume was similar to controls (30.2 ml vs 26.7 ml, p = 0.716). 6/9 BAPAs were initially missed on CTA. VWI showed thick (2.9 mm ± 2.7) bright enhancement (stalk ratio 1.05 ± 0.12), similar to controls with ruptured aneurysms (0.95 ± 0.23, p = 0.551), and greater than unruptured aneurysms (0.43 ± 0.11, p < 0.001). All were initially managed conservatively. Six thrombosed spontaneously. Three grew and had difficult access with few good endovascular options and were treated through a subtemporal craniotomy without complication. None rebled. At 3 months, all presenting in poor grade were mRS 3-4 and those in good grade mRS 1-2.

CONCLUSIONS

Despite their small size, BAPAs present with similar volume SAH, WFNS grade and hydrocephalus to other aneurysms. They are difficult to identify on CTA but enhance strikingly on VWI. The majority thrombosed. Initial conservative management reserving treatment for growth was associated with no rebleeds or complications.

Susceptibility weighted imaging for ruptured basilar artery perforator aneurysms in the setting of angiographically negative subarachnoid hemorrhage

BACKGROUND

Ruptured basilar artery perforator aneurysms (BAPAs), defined as microaneurysms which develop in basilar perforator arteries without direct involvement of the basilar trunk, represent a rare cause of subarachnoid hemorrhage (SAH). The diagnosis of BAPAs is difficult because of their small size, with high rates of negative angiography. The development of high-resolution MRI could increase the diagnostic performance. In this study we describe the usefulness of susceptibility weighted imaging (SWI) for the diagnosis of ruptured BAPAs.

METHODS

In a case series, we retrospectively collected data of patients admitted to our institution from 2018 to 2021 for SAH with negative CT angiography who underwent MRI (including SWI) and DSA during hospitalization.

RESULTS

Eight patients with a definitive diagnosis of ruptured BAPA and five patients with a definitive diagnosis of angiogram-negative SAH were included. In all of the patients with BAPAs MRI showed a focal, thick, semi-circumferential SWI hypointensity covering the vessel wall at the level of the BAPA subsequently revealed on DSA; this phenomen is known as 'SWI capping'. No SWI capping was observed in the five patients with a definitive diagnosis of angiogram-negative SAH.

CONCLUSION

SWI capping appears to be a reliable indirect sign for the diagnosis and localization of ruptured BAPAs, a rare form of microaneurysm easily misdiagnosed on DSA in initial angiogram-negative SAH.

Utility of flow diverters in treatment of acutely ruptured uncoilable aneurysms of the posterior circulation of the brain

PURPOSE

Aim of this study is to evaluate safety and efficacy of flow diverters (FDs) in treatment of acutely ruptured posterior circulation aneurysms MATERIALS AND METHODS: Databases of three participating institutions were retrospectively scanned for patients in whom FD placement was attempted for treatment of acutely ruptured vertebrobasilar aneurysms. An interval of 14 days or fewer between the latest ictus and treatment was used as inclusion criterion. Patients with dolichoectasia of vertebrobasilar arteries were excluded. If necessary, adjunctive techniques including coiling or stenting were utilized. Clinical outcomes were graded using mWFNS (modified World Federation of Neurosurgical Societies Scale) and mRS (modified Rankin Scale). Aneurysmal occlusion was defined as Raymond-Roy Class 1. Spearman's (ρ) test was used to assess the correlation between variables. Univariate and multivariate logistic regression were used to assess outcomes.

RESULTS

31 patients (25 women, mean age: 52.7 ± 15.2) harboring 32 aneurysms (16 non-saccular, mean size: 11.4 ± 7 mm) were included. Mean number of FDs used was 1.22 ± 0.42. In six cases, adjunctive coiling and in five cases, apposing stent placement were used. Overall mortality rate and procedure-related mortality rates were 22.5% (7/31) and 9.6% (3/31), respectively. At a mean imaging follow-up of 17.2 ± 12.6 months, total occlusion was achieved in 22 aneurysms (91.6%). Univariate analysis showed that mortality was positively correlated with vasospasm (ρ = 0.600, p < 0.05), higher mWFNS Scale (ρ = 0.685, p < 0.05), higher modified Fischer Score (ρ = 0.609, p < 0.05), higher mRS (ρ = 0.594, p < 0.05) on admission and negatively correlated with saccular morphology (ρ = -0.529, p < 0.05). Multivariate logistic regression identified mWFNS on admission as a significant predictor. (OR: 7.148, 95% CI 1.777-28.758, p: 0.01). Adjunctive coiling positively correlated with aneurysm occlusion. (ρ = 0.522, p < 0.05).

CONCLUSION

The procedure-related morbidity and mortality is not negligible. However, the risks and efficacy associated with FDs are acceptable, especially when adjunctive coiling is possible, given the lack of treatment alternatives.

Spontaneous subarachnoid hemorrhage caused by ruptured aneurysm of basilar trunk perforator: a case report and literature review

Background

Aneurysm of basilar perforator was rarely reported in the literature. It is difficult to treat due to its small size and deep-seated location. Excessive treatment may cause complications that resulted from ischemic events of parent perforators. Therefore, it is important to make clinical strategy for such patients to improve the prognosis.

Case presentation

One case, who presented as spontaneous subarachnoid hemorrhage, despite the negative result in computed tomography angiography firstly, was diagnosed angiographically as a ruptured aneurysm of the basilar perforator. A good clinical outcome of the case was achieved during the follow-up after conservative observation for 2 months, as well as the disappearance of previous lesion from angiography.

Conclusions

Aneurysm located at perforator of basilar trunk was rare and difficult to treat. Conservative observation for certain cases with periodic angiography follow-up was considered in order to prevent the patients from potential iatrogenic effects.