A dissecting aneurysm of a basilar perforating artery

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.

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.

Ruptured basilar artery perforator aneurysm: a novel mechanism of pure subarachnoid hemorrhage in moyamoya disease. Illustrative case

BACKGROUND

Pure subarachnoid hemorrhage (SAH) in patients with moyamoya disease is a rare occurrence. Three underlying mechanisms have been described previously, except for ruptured aneurysm of the circle of Willis. Herein, the authors describe a novel mechanism: rupture of a perforator aneurysm in moyamoya disease.

OBSERVATIONS

A 51-year-old man experienced sudden onset of severe headache and vomiting. Computed tomography showed diffuse SAH. Digital subtraction angiography (DSA) showed unilateral moyamoya disease without remarkable etiology of SAH. The patient underwent conservative management with antihypertensive agents. The second DSA on day 17 revealed a slow-filling aneurysm emerging from the basilar top perforating artery. The diagnosis of SAH due to unknown origin was changed to ruptured basilar artery perforator aneurysm (BAPA). The third follow-up DSA on day 159 revealed the resolution of BAPA.

LESSONS

In the case of pure SAH, it is crucial to consider the possibility of perforator aneurysms due to hemodynamic stress caused by moyamoya disease. Repeated DSA is essential for detecting the lesion.

Flow Diverter Treatment of Ruptured Basilar Artery Perforator Aneurysms

Purpose

Ruptured basilar artery perforator aneurysms (BAPAs) represent a very rare cause of subarachnoid hemorrhage and an under-reported subtype of cerebral aneurysm. There is no consensus for the optimal treatment strategy (conservative vs. surgical vs. various endovascular approaches). We aim to present a multicenter experience of BAPA treatment using flow-diverter (FD) stents.

Methods

At five tertiary neurovascular centers, all cases of ruptured BAPAs treated by FD were retrospectively collected. Baseline imaging and clinical characteristics, complications, as well as early and long-term angiographic and clinical outcome (mRS) were analyzed.

Results

Eighteen patients (mean age, 57 years; SD, ±10.7 years) with acute SAH related to a BAPA were treated using 18 FD stents. Aneurysms were detected on initial imaging study in 28%; delayed diagnosis was triggered by clinical deterioration due to rebleeding in 15%. No rebleeding after FD was seen, 28% developed FD-related ischemic complications. At long term (n = 16), overall mortality was 13% (2/16), and favorable outcome (mRS 0–2) was 81% (13/16). All BAPAs (n = 13) were completely occluded at long-term angiographic follow-up.

Conclusion

In our multicenter experience, FD treatment of ruptured BAPAs appears to have comparable safety and efficacy outcomes to FD treatment of other ruptured posterior circulation aneurysms as well as to the conservative management of BAPAs. This treatment strategy for a ruptured BAPA achieved a high rate of angiographic occlusion and favorable clinical outcome; however, as the conservative management also seems to offer similar clinical outcomes an individualized treatment decision is warranted. Future prospective studies comparing both approaches are required.

Supplementary Information

The online version of this article (10.1007/s00062-021-01133-y) contains supplementary material, which is available to authorized users.

Comparison between stenting and conservative management of posterior circulation perforator aneurysms: Systematic review and case series

PURPOSE

Posterior circulation perforator aneurysms (PCPAs) are a rare type of intracranial aneurysms whose natural history and optimal clinical management are still largely unexplored. This study aims to report our experience with treating ruptured PCPAs and to provide a systematic review of the literature to compare the two most established treatment options, endovascular stenting, and conservative management including administration of antifibrinolytic drugs and watchful waiting.

METHODS

We performed a systematic review of the literature following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Major databases were searched for case reports and case report series written in the English language between 1995 and 2020. Additionally, we retrospectively reviewed our stroke center database for cases of ruptured PCPAs between January 2014 and July 2020. Endovascular stenting and conservative treatment were compared using endpoints, including favorable outcome rate (mRS 0-2), occlusion rate, mortality rate, periinterventional complication rate, and re-hemorrhage rate.

RESULTS

We identified 31 patients treated endovascularly using stents and 33 patients treated conservatively, with the administration of antifibrinolytic drugs in 3 of them. Our analysis showed no statistically significant difference between the groups, except for the occlusion rate.

CONCLUSIONS

The optimal management strategy of PCPAs is still unknown, but stenting can be considered as an effective occlusion method with an acceptable complication rate. Preventive ventricular drainage may be necessary due to the high hydrocephalus rate encountered in ruptured PCPAs.

Ruptured Basilar Artery Perforator Aneurysm: A Case Report and Review of the Literature

Basilar artery perforator aneurysms (BAPAs) are a rare cause of subarachnoid hemorrhage (SAH), and the natural history is still unknown. Herein, we report a case of ruptured BAPA that appeared during the observation period and then spontaneously disappeared; we have also conducted a review of the literature and performed an analysis based on the type of management. This case of BAPA had a unique course, and our observations may help establish a treatment strategy. A 60-year-old man presented with acute diffuse SAH, World Federation of Neurosurgical Societies (WFNS) Grade II and Fisher Grade 3. Initial three-dimensional digital subtraction angiography (DSA) did not show the source of the hemorrhage. DSA performed on day 39 showed a BAPA with a diameter of 3 mm at the posterior surface of the upper third of the basilar artery. Conservative treatment was chosen. DSA performed on day 64 showed complete resolution of the aneurysm. BAPAs are likely pseudoaneurysms, and not saccular aneurysms, caused due to dissection of basilar perforator arteries. BAPAs are often not recognized on initial imaging, and hence, it is necessary to repeat the DSA examination. Considering the relatively high rate of spontaneous resolution, we chose conservative management. When BAPAs enlarge or do not disappear after conservative treatment, additional therapy such as multiple stents should be considered.

Conservative Management and Natural History of Ruptured Basilar Perforator Artery Aneurysms: Two Cases and Literature Review

BACKGROUND

Basilar perforator aneurysms are rare causes of subarachnoid hemorrhage and their natural history is poorly characterized. Although various treatment strategies have been reported, conservative management is an option that has been associated with a high likelihood of spontaneous resolution.

CASE DESCRIPTION

Here we present 2 cases of subarachnoid hemorrhage, 1 diffuse and the other perimesencephalic, due to small ruptured basilar perforator artery aneurysms. These aneurysms were only identified after repeat angiography. Conservative management with serial imaging was pursued. Both patients did well clinically and repeat imaging demonstrated spontaneous resolution of the ruptured aneurysms. We also provide a literature review of ruptured basilar perforator aneurysms, showing a ~10% re-rupture rate within the early post-rupture period but otherwise a high rate of spontaneous resolution.

CONCLUSIONS

Although basilar perforator aneurysms can re-rupture, there is also a high likelihood of spontaneous resolution. Given the challenges of treatment, conservative management is an option that can be considered.

A systematic review of non-trunk basilar perforator aneurysms: is it worth chasing the small fish?

BACKGROUND AND PURPOSE

Non-trunk basilar artery perforator aneurysms (BAPAs) are rare intracranial vascular pathologies that have long been underdiagnosed, under-reported, and under-analyzed. We performed a systematic review of the efficacy and safety endpoints between conservative and active treatment approaches for non-trunk BAPAs.

METHODS

Major databases were analyzed for relevant publications between 1995 and 2019. Studies comparing the outcomes between conservative and active treatment approaches such as coiling, stenting, clipping, liquid embolization, and flow diversion were included. Mortality rate, rate of permanent neurological deficit as determined by the modified Rankin Score (mRS), rate of second treatment occurrence, and perioperative complication rate were also assessed.

RESULTS

A total of 24 studies, including 54 patients with 56 non-trunk BAPAs, were included. The mean maximum aneurysm diameter was 2.70 mm (range 1-10). A diagnosis was achieved with the initial DSA in 50.0% (27/54) of the patients. A conservative approach was used in 16 patients while active treatment was used in the other 38. Thirteen of 15 (86.7%) patients in the conservative group and 27/34 (79.4%) in the active treatment group had an mRS score 0-2. A non-significant higher odds of a positive outcome was observed in the conservative group (OR 1.51, 95% CI 0.50 to 4.54). The event-related mortality rate was 3.55% (3/54) with one procedure-related death in the active treatment group.

CONCLUSIONS

In patients with non-trunk BAPAs unamenable to active treatment, conservative approaches may result in acceptable functional outcomes and low morbidity. Small sample sizes and under-reporting of outcomes warrant further study.

Basilar artery perforator aneurysms: Report of 9 cases and review of the literature

Basilar perforator artery aneurysms (BAPA's) are an under-recognised cause of sub-arachnoid haemorrhage (SAH). We present our single centre experience of BAPA's and review of the literature. We performed a retrospective review of our prospectively maintained database to identify all BAPA's that presented acute SAH between February 2009 and February 2018. We identified 9 patients (male = 7), each with a single aneurysm, and average age 55 ± 9.7 years. All aneurysms were small, 2.1 ± 0.5 mm (range 1-3 mm). Three aneurysms were not detected on initial angiography. Six aneurysms were treated with flow diversion, 3 were managed conservatively. No repeat haemorrhage occurred in the flow diverted patients. One patient treated conservatively suffered a repeat haemorrhage and died (mRS 6). Follow up imaging (n = 7), at average 5.6 months (range 3-12 months), showed complete occlusion in all the flow-diverted aneurysms and no change in one conservatively managed patient. There was no evidence of perforator infarction on the follow-up post treatment imaging. Clinical follow-up data was available in 8 patients, 6 of whom (75%) had a good outcome (mRS ≤ 2). A high index of suspicion is required to diagnose BAPA. Flow diversion can be used to treat BAPA's with acceptable risk of perforator infarction and low risk of repeat haemorrhage.

Should we treat aneurysms in perforator arteries from the basilar trunk? Review of 49 cases published in the literature and presentation of three personal cases

Basilar trunk perforator artery aneurysms are rare. Their diagnosis and treatment are difficult, controversial, and challenging. Analysis of 52 cases (49 documented in the literature and three personal cases) clearly shows a re-bleeding rate of 15% in patients whose aneurysm has not been occluded and 0% in treated patients ( p < 0.05). The most effective treatment, and the one that presents the least complication, is double-stenting across the basilar trunk.

Basilar Perforator Aneurysms: Presentation of 4 Cases and Review of the Literature

OBJECTIVE

Basilar perforator aneurysms (BPAs) are rare lesions that present a therapeutic challenge. We present 4 cases of ruptured BPAs treated either conservatively or by flow diverter deployment and review the literature.

METHODS

Patients (age 78, 59, 53, and 62 years) presented with World Federation of Neurological Societies grade I-IV and Fisher grade 3-4 subarachnoid hemorrhage. Initial angiography results were normal in 3 patients and necessitated a second angiography. BPA diameter was 0.5-3 mm; BPAs were located in the mid-third of the basilar artery in 2 patients and the upper third in 2 patients.

RESULTS

All patients were managed conservatively. One patient experienced rebleeding 10 days after initial ictus, which required the deployment of a flow diverter in the basilar artery. One patient developed a severe spontaneous pontine ischemic stroke with severe quadriparesis and refused further imaging. He was clinically stable at 1-year clinical follow-up. The other 3 patients showed complete resolution of BPAs on control follow-up imaging.

CONCLUSIONS

Ruptured BPAs are rare lesions that may heal spontaneously or be associated with spontaneous ischemic brainstem stroke or rerupture. These lesions can be managed conservatively initially with flow diverter deployment the most suitable therapeutic alternative in selected cases. Larger studies are needed to fully understand the natural history and refine the therapeutic strategy for these lesions.