Vertebrobasilar Fusiform Aneurysms

Open surgical treatment of basilar artery aneurysms in the interventional therapy era

PURPOSE

The purpose of this study was to describe the effectiveness and evaluation of open surgical treatment of basilar artery aneurysms in the context of interventional therapy era, including surgical clipping and blood reconstruction, by retrospectively analyzing the clinical data of basilar artery aneurysms in our center.

METHODS

Patients with basilar artery aneurysms who were treated at our center were retrospectively included according to the inclusion and exclusion criteria. The basic clinical data, surgical approach, clinical follow-up and prognosis of the enrolled patients were analyzed in detail. In this study, the mRS score was applied to assess the neurological prognosis of the patients, and the relevant data were statistically analyzed using SPSS.

RESULTS

A total of 104 eligible patients treated at our center from January 2010 to August 2023 were included in this study, of which 67 were treated by open surgery and 37 by bypass. For the 67 patients with open surgical clipping, the mean age was 60.0 (52.0, 65.0) years. The maximum diameter of the aneurysms ranged from 2.0 mm to 54.0 mm, with a mean of 13.9 (10.0, 19.0) mm. The mean follow-up time was 38 (20, 58) months. At the last follow-up, 61 (91.0%) completely obliterated aneurysms and 6 (9.0%) incompletely obliterated aneurysms were found. The prognosis was good in 59 (88.1%) patients and poor in 8 (11.9%). After surgical clipping, the difference between complete and incomplete postoperative aneurysm elimination was statistically significant between the favorable and poor prognosis groups (P < 0.001). For the 37 bypass group patients, the mean age was 52.0 (45.5, 59.0) years. The maximum diameter of the aneurysm ranged from 10.5 mm to 55.0 mm, with a mean of 28.55 ± 12.08 mm. Bypass combined with proximal occlusion was performed in 18 (48.6%) patients, and bypass only was performed in 19 (51.4%) patients. Clinical follow-up was 19.0 (10.5, 43.0) months. There were 19 (51.4%) patients with complete elimination of the aneurysm, 13 (35.1%) with incomplete elimination of the aneurysm, and 5 (13.5%) with aneurysm stabilization. The prognosis was good in 32 (86.5%) patients and poor in 5 (13.5%) patients.

CONCLUSION

Treatment of basilar artery aneurysms is challenging. In the context of the rapidly evolving interventional therapy era, open surgery including surgical clipping and bypass is an ideal option for complex basilar artery aneurysms not amenable to intervention.

Fusiform versus Saccular Intracranial Aneurysms-Hemodynamic Evaluation of the Pre-Aneurysmal, Pathological, and Post-Interventional State

Minimally-invasive therapies are well-established treatment methods for saccular intracranial aneurysms (SIAs). Knowledge concerning fusiform IAs (FIAs) is low, due to their wide and alternating lumen and their infrequent occurrence. However, FIAs carry risks like ischemia and thus require further in-depth investigation. Six patient-specific IAs, comprising three position-identical FIAs and SIAs, with the FIAs showing a non-typical FIA shape, were compared, respectively. For each model, a healthy counterpart and a treated version with a flow diverting stent were created. Eighteen time-dependent simulations were performed to analyze morphological and hemodynamic parameters focusing on the treatment effect (TE). The stent expansion is higher for FIAs than SIAs. For FIAs, the reduction in vorticity is higher (Δ35-75% case 2/3) and the reduction in the oscillatory velocity index is lower (Δ15-68% case 2/3). Velocity is reduced equally for FIAs and SIAs with a TE of 37-60% in FIAs and of 41-72% in SIAs. Time-averaged wall shear stress (TAWSS) is less reduced within FIAs than SIAs (Δ30-105%). Within this study, the positive TE of FDS deployed in FIAs is shown and a similarity in parameters found due to the non-typical FIA shape. Despite the higher stent expansion, velocity and vorticity are equally reduced compared to identically located SIAs.

Association Between Serum Homocysteine Concentration, Aneurysm Wall Inflammation, and Aneurysm Symptoms in Intracranial Fusiform Aneurysm

RATIONALE AND OBJECTIVES

The pathophysiology of fusiform intracranial aneurysm (FIA) involves inflammatory processes, and homocysteine plays a role in the inflammatory processes in the vessel wall. Moreover, aneurysm wall enhancement (AWE) has emerged as a new imaging biomarker of aneurysm wall inflammatory pathologies. To investigate the pathophysiological mechanisms of aneurysm wall inflammation and FIA instability, we aimed to determine the associations between the homocysteine concentration, AWE, and FIAs' related symptoms.

MATERIALS AND METHODS

We retrospectively reviewed the data of 53 patients with FIA who underwent both high-resolution magnetic resonance imaging and serum homocysteine concentration measurement. FIAs' related symptoms were defined as ischemic stroke or transient ischemic attack, cranial nerve compression, brainstem compression, and acute headache. The contrast ratio of the signal intensity of the aneurysm wall to the pituitary stalk (CRstalk) was used to indicate AWE. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to determine how well the independent factors could predict FIAs' related symptoms. Predictors of CRstalk were also investigated. Spearman's correlation coefficient was used to identify the potential associations between these predictors.

RESULTS

Fifty-three patients were included, of whom 23 (43.4%) presented with FIAs' related symptoms. After adjusting for baseline differences in the multivariate logistic regression analysis, the CRstalk (odds ratio [OR]=3.207, P = .023) and homocysteine concentration (OR=1.344, P = .015) independently predicted FIAs' related symptoms. The CRstalk was able to differentiate between FIAs with and without symptoms (area under the ROC curve [AUC]=0.805), with an optimal cutoff value of 0.76. The homocysteine concentration could also differentiate between FIAs with and without symptoms (AUC=0.788), with an optimal cutoff value of 13.13. The combination of the CRstalk and homocysteine concentration had a better ability to identify symptomatic FIAs (AUC=0.857). Male sex (OR=0.536, P = .018), FIAs' related symptoms (OR=1.292, P = .038), and homocysteine concentration (OR=1.254, P = .045) independently predicted the CRstalk.

CONCLUSION

A higher serum homocysteine concentration and greater AWE indicate FIA instability. Serum homocysteine concentration may be a useful biomarker of FIA instability; however, this needs to be verified in future studies.

Characteristics and evolution of cerebral aneurysms among adults living with HIV: A retrospective, longitudinal case series

OBJECTIVE

Previous research indicates an increased risk of cerebral aneurysm formation in adults living with human immunodeficiency virus (ALWH), however there are few longitudinal studies on the risk factors for and outcomes of cerebral aneurysms in this population. We aim to describe the characteristics and evolution of cerebral aneurysms in a large cohort of ALWH.

MATERIALS AND METHODS

A chart review was completed for all adults evaluated at an urban, safety-net U.S. hospital between January 1, 2000, and October 22, 2021, with history of both HIV and at least one cerebral aneurysm.

RESULTS

A total of 82 cerebral aneurysms were identified amongst 50 patients (52% female sex). Forty-six percent of patients with a nadir CD4 count less than 200 cells/mm³ (N=13) and 44% of patients with maximum viral load >10,000 copies/mL (N=18) developed new aneurysms or were found to have aneurysm growth over time compared with 29% of patients with a CD4 nadir above 200 cells/mm³ (N=21) and 22% of patients with maximum viral load </= 75 copies/mL (N=9). New aneurysms were found, or existing aneurysms grew in 67% of those not on antiretroviral therapy (ART) at time of aneurysm diagnosis (N=6), 38% of those with inconsistent ART use (N=8), and 21% of those with consistent ART (N=19).

CONCLUSIONS

Among ALWH, lower CD4 nadir, higher zenith viral load, and inconsistent ART use may contribute to aneurysm formation or growth. Further studies are needed to more thoroughly characterize the association between immunologic status and cerebral aneurysm formation.

Aneurysm wall enhancement, hemodynamics, and morphology of intracranial fusiform aneurysms

Background and objective

Intracranial fusiform aneurysms (IFAs) are considered to have a complex pathophysiology process and poor natural history. The purpose of this study was to investigate the pathophysiological mechanisms of IFAs based on the characteristics of aneurysm wall enhancement (AWE), hemodynamics, and morphology.

Methods

A total of 21 patients with 21 IFAs (seven fusiform types, seven dolichoectatic types, and seven transitional types) were included in this study. Morphological parameters of IFAs were measured from the vascular model, including the maximum diameter (Dmax), maximum length (Lmax), and centerline curvature and torsion of fusiform aneurysms. The three-dimensional (3D) distribution of AWE in IFAs was obtained based on high-resolution magnetic resonance imaging (HR-MRI). Hemodynamic parameters including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), gradient oscillatory number (GON), and relative residence time (RRT) were extracted by computational fluid dynamics (CFD) analysis of the vascular model, and the relationship between these parameters and AWE was investigated.

Results

The results showed that Dmax (p = 0.007), Lmax (p = 0.022), enhancement area (p = 0.002), and proportion of enhancement area (p = 0.006) were significantly different among three IFA types, and the transitional type had the largest Dmax, Lmax, and enhancement area. Compared with the non-enhanced regions of IFAs, the enhanced regions had lower TAWSS but higher OSI, GON, and RRT (p &lt; 0.001). Furthermore, Spearman’s correlation analysis showed that AWE was negatively correlated with TAWSS, but positively correlated with OSI, GON, and RRT.

Conclusion

There were significant differences in AWE distributions and morphological features among the three IFA types. Additionally, AWE was positively associated with the aneurysm size, OSI, GON, and RRT, while negatively correlated with TAWSS. However, the underlying pathological mechanism of the three fusiform aneurysm types needs to be further studied.

Destructive strategies in treating cerebrovascular pathology: Review and treatment algorithm

The goal of cerebrovascular pathology treatment is most often to angiographically eradicate a lesion with the lowest probability of morbidity. Destructive strategies using parent vessel occlusion are less commonly considered in the modern era. We review principles of parent vessel occlusion for treatment of cerebrovascular pathology and select cases to demonstrate these principles. Many common cerebrovascular conditions have been safely and effectively treated with destructive strategies including intracranial aneurysms, traumatic craniocervical vascular injuries, and oncologic indications such as carotid blowout. Avoiding procedural morbidity in these procedures involves assessment of collaterals distal to a planned parent vessel occlusion, determination of this arterial segment's eloquence, prevention of distal migration of endovascular devices or thrombus, and prevention of stump emboli. An algorithm for case selection and method of destructive technique versus a reconstructive approach can be used. Destructive strategies for treating cerebrovascular pathology are still relevant and can be applied safely in appropriately selected cases.

Interventional treatment of basilar trunk artery aneurysms associated with situs inversus totalis: A case report

Basilar trunk artery aneurysm (BTAA) has an overall low incidence in intracranial aneurysm, but its rupture is associated with high morbidity and mortality in older people. Situs inversus totalis (SIT) is a rare congenital abnormality characterized by visceral rotation and vascular abnormalities. It has been described in several uncommonly clinical cases, along with middle cerebral artery aneurysms and large carotid cavernous aneurysms. However, the association between interventional embolization for BTAA and SIT has not been reported. We described the angiography findings and interventional treatment of the association of BTAA with SIT.

Transient Ischemic Attack Due to Unruptured Basilar Artery Aneurysm

Intracranial aneurysms are typically asymptomatic. They are usually incidentally detected or detected only after rupture. Ischemic stroke or transient ischemic attack (TIA) due to unruptured intracranial aneurysms (UIAs) is rare. A 79-year-old male with well-controlled hypertension and hypothyroidism, presented with complaints of sudden-onset weakness of the right upper limb and lower limb, followed by altered sensorium and a fall. Two hours later, he had fully recovered. Neurologic examination was unremarkable. Computed tomography of the brain revealed a dilated and tortuous basilar artery, suggestive of an aneurysm compressing the left midbrain and pons, with no evidence of intracranial bleed. Further, magnetic resonance imaging with an angiogram revealed multiple lacunar infarcts in the posterior circulation, distal to the aneurysm. Finally, a cerebral angiogram confirmed a partially thrombosed, fusosaccular aneurysm, arising from the left vertebral and basilar arteries. In view of frailty and long vessel segment involvement, surgery was not advised. He was treated medically, with appropriate antiplatelets and prophylactic antiepileptics. On follow-up, he had no neurologic deficit and had suffered no later ischemic or hemorrhagic events. UIAs may cause brainstem strokes via thrombosis of the parent vessel, emboli from the thrombus, or compression of the parent artery. In our case, compression, the least common mechanism, appears to have caused the TIA, with emboli potentially responsible for the silent lacunar infarcts. Fusiform aneurysms of the vertebrobasilar system have a poor natural history. In elderly patients presenting with ischemic events due to UIAs of the vertebrobasilar system, surgical intervention can be risky. So, medical treatment with antiplatelets is recommended. UIAs should be considered in the differential diagnosis of patients with TIAs, and such patients should have a visualization of intracranial arteries.

[Diagnosis and treatment of non-saccular vertebrobasilar aneurysms]

OBJECTIVE

To systematize the data on diagnosis and treatment of non-saccular vertebrobasilar aneurysms.

MATERIAL AND METHODS

We have analyzed modern and fundamental studies in the PubMed database for the period 1969-2020. The following keywords were used: non-saccular aneurysm, dolichoectasia, vertebrobasilar pool. Fifty-nine studies including 1 meta-analysis, 9 case reports, 24 reviews and 25 original articles were selected.

RESULTS

Analysis of literature data indicates various unresolved problems associated with difficult diagnosis and choice of treatment that results high rates of disability and mortality.

CONCLUSION

Data on anatomical features of non-saccular aneurysms, such as presence or absence of perforating arteries within the affected arterial segment, analysis of electrophysiological changes following brainstem compression by aneurysm can serve as factors that will improve treatment outcomes in these patients.

Microsurgical Treatment Strategy of Vertebral Artery Fusiform Aneurysm-From the Standpoint of Hemodynamic Integrity and Perforator Preservation

During treatment of vertebral artery (VA) fusiform aneurysms, it is critical to preserve peripheral perforators and anterograde blood flow of the VA and to reduce hemodynamic load to the contralateral VA. Even in the era of endovascular treatment, there are still many benefits to using microsurgical treatments with appropriate clip application and preservation of the perforators around the aneurysm, in conjunction with various bypass techniques. The ideal microsurgical technique involves reconstructive clipping that obliterates the aneurysm but preserves anterograde blood flow of the VA, followed by isolation of the aneurysm and VA reconstruction. If these two methods are unavailable, proximal clipping of the aneurysm combined with flow-augmentation bypass to the distal branch can be considered as an alternative surgical management. We discuss the microsurgical treatment of unruptured VA fusiform aneurysms in our surgical cases on the basis of a review of the current literature.

Optical Coherence Tomography for Neurovascular Disorders

Diagnosis of cerebrovascular disease includes vascular neuroimaging techniques such as computed tomography (CT) angiography, magnetic resonance (MR) angiography (with or without use of contrast agents) and catheter digital subtraction angiography (DSA). These techniques provide mostly information about the vessel lumen. Vessel wall imaging with MR seeks to characterize cerebrovascular pathology, but with resolution that is often insufficient for small lesions. Intravascular imaging techniques such as ultrasound and optical coherence tomography (OCT), used for over a decade in the peripheral circulation, is not amendable to routine deployment in the intracranial circulation due to vessel caliber and tortuosity. However, advances in OCT technology including the probe profile, stiffness and unique distal rotation solution, holds the promise for eventual translation of OCT into the clinical arena. As such, it is apropos to review this technology and present the rationale for utilization of OCT in the cerebrovasculature.

Giant Vertebrobasilar Fusiform Aneurysm Mass Effect Heralds Rapid in Situ Thrombosis and Ischemic Stroke in the Setting of Ulcerative Colitis

Here we describe a case of brainstem infarction secondary to rapid thrombus formation in a giant vertebrobasilar fusiform aneurysm (GVBFA) that was preceded clinically by several months of headaches and dizziness initially attributable to mass effect. Less than a month after initial identification of the aneurysm, a large partially-occluding thrombus formed leading to infarction of the brainstem. Interestingly, this patient also had ulcerative colitis, which has been associated with acquired hypercoagulability. Balancing risk versus benefit in the management of GVBFA to prevent morbidity and mortality is very challenging; thus more information is needed to better stratify treatment options for patients, particularly those that may have an accelerating clinical course or co-morbidities that increase clotting risk.

Pipeline Embolization Device With Adjunctive Coils for the Treatment of Unruptured Large or Giant Vertebrobasilar Aneurysms: A Single-Center Experience

Objective: To evaluate effectiveness and safety of Pipeline embolization device (PED) for large or giant verterbrobasilar aneurysms (LGVBAs), and to compare the therapeutic effects of PED with and without adjunctive coils. Methods: We retrospectively analyzed 21 cases of unruptured LGVBAs who were treated in our hospital with PED. These cases were divided into "PED group" and "PED with adjunctive coils group." We compared the aneurysm characteristics and treatment outcomes between the two groups. Results: The overall neurological complication rate was 28.6% (6/21) and the mortality rate was 4.8% (1/21). There were 12 patients in the PED group and nine in the PED with adjunctive coils group. There were no significant differences in age, smoking, hypertension, aneurysm size, aneurysm location, or operation time between the two groups. The complete aneurysm embolization rate and favorable outcome rate (modified Rankin Scale = 0,1) of the PED with adjunctive coils group was 78% (7/9) and 100% (9/9), respectively, which were both better compared with the PED group with 63.6% (7/11) and 83% (10/12), respectively. However, these differences were not statistically significant. Conclusion: The effectiveness and safety of PED for LGVBAs is acceptable. Treatment results did not differ between the PED and PED with adjunctive coils groups; therefore, whether coils should be used may depend the operator. Our results suggest that correct use of the coils does not increase complications. We suggest that PED with adjunctive coils should be used for some selected LGVBAs.

Rerupture Following Flow Diversion of a Dissecting Aneurysm of the Vertebral Artery: Case Report and Review of the Literature

BACKGROUND

Dissecting aneurysms of the posterior cerebral circulation can wield significant treatment challenges with devastating clinical outcomes. Despite an expanded therapeutic armamentarium, these vascular lesions remain relatively difficult to diagnose and portend high associated morbidity and mortality.

METHODS

A ruptured, fusiform, dissecting aneurysm of the mid V4 segment of the right vertebral artery (VA) distal to the posterior inferior cerebellar artery origin resulted in a Hunt and Hess grade 5, Fisher scale score 4 subarachnoid hemorrhage. The lesion incorporated 360 degrees of the vessel wall and extended across an area measuring 11 mm in length and 6.8 mm in width at maximum dimension. The vascular lesion was treated with 2 overlapping Pipeline Embolization Devices.

RESULTS

Digital subtraction angiography demonstrated an origin of the right posterior inferior cerebellar artery mildly stenosed by the dissecting aneurysm. The left VA was markedly hypoplastic. After deployment of 2 overlapping Pipeline Embolization Devices, the aneurysm neck was well covered with appropriate positioning of the stent construct with good apposition to the vessel wall. There was contrast stasis within the aneurysm. The patient was managed with dual antiplatelet therapy. He demonstrated initial clinical and radiographic improvement. However, on the night of the second postprocedure day, the patient succumbed to rerupture of the aneurysm.

CONCLUSIONS

The literature posits that nonsaccular, fusiform, and dissecting aneurysms of the vertebrobasilar circulation can be occluded with consistency and success using flow diversion techniques. Endovascular treatment of a ruptured dissecting aneurysm of the VA is technically feasible and can be performed with or without parent artery occlusion. Outcomes following flow diversion of the posterior circulation may depend on the location of the dissection and viability of collateral circulation. In the present case, adequate coverage of the aneurysm did not portend a positive outcome.

Basilar trunk artery aneurysm presenting with brainstem stroke

Basilar trunk artery aneurysms are extremely rare lesions that account for only 2.1% of all intracranial aneurysms. They are mostly recognized in patients around the age of 60, show a slight male predominance, and are associated with high morbidity and mortality. Chronic mural bleeding ectasia is the most common subtype of basilar trunk artery aneurysms. Its median maximum diameter ranges between 11 and 21 mm and is incidentally detected in more than half of the cases. Herein, we present a 58-year-old male patient who presented with brain stem stroke due to a chronic mural bleeding ectasia with a maximum diameter of 27 mm and died in the first week after admission.

Clinical utility and versatility of the petrous segment of the internal carotid artery in revascularization

Direct approaches to high cervical lesions, including tumors and aneurysms, carry significant risks. This renders alternative approaches desirable, with vascular disease amenable to exclusion and revascularization to the intracranial circulation, including the petrous or supraclinoid segments of the internal carotid artery (ICA). The cervicopetrous ICA bypass via saphenous venous grafting has proven an effective strategy for treating and excluding these lesions. In current practice, this is performed via an extradural subtemporal approach to access the petrous segment of the ICA and a cervical incision for access to the cervical ICA. The venous graft is alternately tunneled subcutaneously or in situ through the cervical ICA, with the latter eschewing external compression, kinking, and torsion, which increases risk of graft thrombosis with the former. Maxillary or middle meningeal arteries may also serve as donors to the petrous ICA. Moreover, the petrous ICA may be used as a donor in revascularization procedures, to the supraclinoid segment of the ICA and the middle cerebral artery, with petrous supraclinoid and petrous-MCA bypasses described. Clinical utility and operative approaches bypassing to or from the petrous ICA in revascularization procedures are reviewed and discussed.

Wall enhancement of intracranial saccular and fusiform aneurysms may differ in intensity and extension: a pilot study using 7-T high-resolution black-blood MRI

PURPOSE

To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7 T.

METHODS

Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms.

RESULTS

In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0 mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002).

CONCLUSION

Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology.

KEY POINTS

• Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

Nonsaccular aneurysms: A wide comparison between the four main types

Background:

The present study aims to present the most important considerations when it comes to patients features, clinical presentation, localization, morphology, pathogenesis, and the best treatment for each type of the nonsaccular aneurysms.

Methods:

We performed a literature review using PubMed. The search was limited to the studies published in English, from 2010 to 2017.

Results:

Data about the clinical presentation; the aneurysm pathogenesis, morphology, and localization; the patient features; and about the surgical or endovascular approach were analyzed for the four types of nonsaccular aneurysms presented.

Conclusion:

All types of nonsaccular aneurysms have a higher prevalence in young adults. Men are more affected by fusiform and mycotic aneurysms while women suffer more with blister-like aneurysms (BLAs). The mycotic and the BLAs affect more the anterior circulation while the fusiform affects more the posterior circulation. Mycotic and blister-like has as its major complication and clinical presentation the hemorrhage; however, the fusiform aneurysms usually present ischemia and/or mass effect. The reconstructive endovascular techniques for all types of nonsaccular aneurysms presented as the treatment with the best outcomes. Among this technique, the flow diversion presented good results in all types of aneurysms and it seems to promote the best outcomes.

Fusiform aneurysms: A review from its pathogenesis to treatment options

Background

This study aims to present the most important considerations when it comes to patients features, clinical presentation, localization, and morphology of the aneurysm and the treatments outcomes of the fusiform aneurysms.

Methods

We performed a literature review using PubMed. The search was limited to the studies published in English, from 2003 to 2017.

Results

The studies analyzed that showed data about the patient features, clinical presentation, the aneurysm localization, morphology, and pathogenesis didn't present much divergence. The surgical and the endovascular approach showed similar treatments outcomes. The reconstructive techniques seem to be safer than the deconstructive. The flow diversion is a technique that showed great results.

Conclusion

Most of the patients are men, younger than 50 years old, pediatric patients are the most affected. Surgical procedures still have an important place in this field. Reconstructive and deconstructive techniques are both effective; the reconstructive techniques are possibly safer than deconstructive techniques. The most important feature of an aneurysm to predict a bad prognose is to determine if the aneurysm is ruptured. The reconstructive EVT accompanied by dual antiplatelet after and before the procedure showed the best results to treat the basilar fusiform aneurysms. Deconstructive treatment including posterior inferior cerebellar artery occlusion should be considered.

Natural History of Vertebrobasilar Dolichoectatic and Fusiform Aneurysms: A Systematic Review and Meta-Analysis

Background and Purpose: Vertebrobasilar non-saccular and dolichoectatic aneurysms (VBDA) are a rare type of aneurysm and are generally associated with poor prognosis. In order to better characterize the natural history of VBDAs, we performed a systematic review and meta-analysis of the literature to determine rates of mortality, growth, rupture, ischemia, and intraparenchymal hemorrhage. Materials and Methods: We searched the literature for longitudinal natural history studies of VBDA patients reporting clinical and imaging outcomes. Studied outcomes included annualized rates of growth, rupture, ischemic stroke, intracerebral hemorrhage (ICH), and mortality. We also studied the association between aneurysm morphology (dolichoectatic versus fusiform) and natural history. Meta-analysis was performed using a random-effects model using summary statistics from included studies. Results: Fifteen studies with 827 patients and 5,093 patient-years were included. The overall annual mortality rate among patients with VBDAs was 13%/year (95% CI 8–19). Patients with fusiform aneurysms had a higher mortality rate than those with dolichoectatic aneurysms, but this did not reach statistical significance (12 vs. 8%, p = 0.11). The overall growth rate was 6%/year (95% CI 4–13). Patients with fusiform aneurysms had higher growth rates than those with dolichoectatic aneurysms (12 vs. 3%, p < 0.0001). The overall rupture rate was 3%/year (95% CI 1–5). Patients with fusiform aneurysms had higher rupture rates than those with dolichoectatic aneurysms (3 vs. 0%, p < 0.0001). The overall rate of ischemic stroke was 6%/year (95% CI 4–9). Patients with dolichoectatic aneurysms had higher ischemic stroke rates than those with fusiform aneurysms, but this did not reach statistical significance (8 vs. 4%, p = 0.13). The overall rate of ICH was 2%/year (95% CI 0–8) with no difference in rates between dolichoectatic and fusiform aneurysms (2 vs. 2%, p = 0.65). Conclusion: In general, the natural history of ­VBDAs is poor. However, dolichoectatic and fusiform ­VBDAs appear to have distinct natural histories with substantially higher growth and rupture associated with fusiform aneurysms. These findings suggest that these aneurysms should be considered separate entities. Further studies on the natural history of vertebrobasilar dolichoectatic and fusiform aneurysms with more complete follow-up are needed to better understand the risk factors for progression of these aneurysms.

Endovascular management of fusiform aneurysms in the posterior circulation: the era of flow diversion

Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

Imaging Characteristics of Growing and Ruptured Vertebrobasilar Non-Saccular and Dolichoectatic Aneurysms

Background and Purpose—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms generally have a poor natural history. We performed a study examining the natural history of vertebrobasilar, nonsaccular, and dolichoectatic aneurysms receiving serial imaging and studied imaging characteristics associated with growth and rupture.

Methods—

We included all vertebrobasilar dolichoectatic, fusiform, and transitional aneurysms with serial imaging follow-up seen at our institution over a 15-year period. Two radiologists and a neurologist evaluated aneurysms for size, type, mural T1 signal, mural thrombus, daughter sac, mass effect, and tortuosity. Primary outcomes were aneurysm growth or rupture. Univariate analysis was performed with chi-squared tests for categorical variables and Student’s t test or analysis of variance for continuous variables. Multivariate logistic regression analysis was performed to identify variables independently associated with aneurysm growth or rupture.

Results—

One hundred and fifty-two patients with 542 patient-years (mean 3.6±3.5 years) of imaging follow-up were included. Aneurysms were fusiform in 45 cases (29.6%), dolichoectatic in 75 cases (49.3%), and transitional in 32 cases (21.1%). Thirty-five aneurysms (23.0%) grew (growth rate=6.5%/year). Eight aneurysms (5.3%) ruptured (rupture rate=1.5%/year). Variables associated with growth and rupture on univariate analysis were size >10 mm (57.6% versus 16.0%, P <0.0001), mural T1 signal (39.7% versus 16.3%, P =0.001), daughter sac (56.3% versus 21.3%), and mural thrombus (45.5% versus 13.4%, P <0.0001). 26.7% of fusiform aneurysms, 9.3% of dolichoectatic aneurysms, and 59.4% of transitional aneurysms grew or ruptured ( P <0.0001). The only variable independently associated with rupture was transitional morphology ( P =0.003).

Conclusions—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms are associated with a poor natural history with high growth and rupture rates. Further research is needed to determine the best treatments for this disease.

Relationship between Postmenopausal Estrogen Deficiency and Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is one of the most severe forms of stroke, which results from the rupture of a cerebral aneurysm. SAH is the only type of stroke with a female predominance, suggesting that reproductive factors may play a significant role in the etiology. Estrogen has important effects on vascular physiology and pathophysiology of cerebral aneurysm and SAH and, thus, potential therapeutic implications. There have been growing bodies of epidemiological and experimental studies which support the hypothesis of a significant relationship between estrogen deficiency and cerebral aneurysm formation with subsequent SAH. This hypothesis is the focus of this review as well as possible pathology-based therapeutics with regard to aspects of molecular pathophysiology, especially related to women's health.