Non-saccular vertebrobasilar aneurysms and dolichoectasia: a systematic literature review

Endovascular Management of Basilar Artery Aneurysms: A Consecutive Series of 124 Patients

BACKGROUND

Currently, there is no established criterion for determining when interventional treatment is necessary or which strategy is appropriate for basilar artery (BA) aneurysms. Through this study, we aimed to propose an algorithm that can effectively determine the optimal endovascular treatment (EVT) option for BA aneurysms.

METHODS

We enrolled patients with BA aneurysms from June 2016 to December 2022 and performed procedures based on the algorithm. The analysis included demographic, clinical, and aneurysmal characteristics, procedural details, complications, angiographic outcomes, and clinical outcomes.

RESULTS

This study included 124 patients (mean age 55.0 years) with a BA aneurysm who underwent EVT. Of these, 21 aneurysms were treated in the setting of subarachnoid hemorrhage. The majority of the aneurysms were located at the basilar apex (74), followed by the basilar trunk (30) and vertebrobasilar junction (20). Coiling was used in 18.5% of the cases, while stent-assisted coiling embolization was chosen for 58.9%. Overlapping stents were used in 12.9%, flow diverter implantation in 3.2%, Y/T stent techniques in 4.8%, and stent adjunctive coiling with unilateral vertebral artery occlusion in only 1.6%. Procedure-related complications occurred in 15 patients (12.1%). The patients had a modified Rankin Scale score of 0.74 ± 1.62; 98 (86.7%) had a good prognosis with modified Rankin Scale scores ranging from 0 to 2 at the last follow-up. Digital subtraction angiography was performed on 105 (84.7%) patients, revealing that 101 (81.5%) achieved complete or near-complete occlusion.

CONCLUSIONS

The criteria for EVT of BA aneurysms based on multi-characteristics were safe and effective. However, further evidence from large cohort studies is needed.

Relationships between intracranial arterial dolichoectasia and small vessel disease in patients with ischaemic stroke: a systematic review and meta-analysis

BACKGROUND

Intracranial arterial dolichoectasia (IADE) is a common arterial finding of dilation, elongation, or both, affecting large intracranial vessels, and associated with vascular risk factors, including hypertension. Associations of IADE with neuroimaging cerebral small vessel disease (CSVD) may be relevant for diagnosis and prognosis in patients with stroke. The study aimed to conduct an updated systematic review and meta-analysis of observational studies to investigate the relationships of IADE with well-defined CSVD markers in patients with ischaemic stroke.

METHODS

We systematically searched PubMed, Embase, and Scopus for studies on IADE in ischaemic stroke patients with fulfilling predefined inclusion criteria. We pooled data to conduct a meta-analysis to compare the prevalence of SVD markers between patients with and without IADE groups using risk ratios (RRs) and 95% confidence intervals (CIs).

RESULTS

From 157 retrieved abstracts, we included six studies from seven publications comprising 6102 patients with ischaemic stroke. The mean age of patients was 52.8 years, and 3691 (60.5%) were male. IADE was diagnosed in 11.4% (95% CI 8.9-13.9) (761) of included patients; 51.8% (3160) had hypertension. Compared to patients without IADE, individuals diagnosed with IADE had a significantly increased prevalence of lacune (RR 1.67, 95% CI 1.36-2.06, P < 0.01, I2 = 0.00%), cerebral microbleeds (CMBs) (RR 2.56, 95% CI 1.53-4.28, P < 0.01, I2 = 84.95%) and white matter hyperintensities (WMHs) (RR 2.17, 95% CI 1.84-2.56, P < 0.01, I2 = 0.00%).

CONCLUSIONS

In patients with ischaemic stroke, IADE is associated with a higher prevalence of CSVD markers, including lacunes, CMBs, and WMHs. Further studies are needed to clarify the mechanisms underlying these associations and their potential relevance for the understanding, diagnosis, and treatment of CSVD.

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.

Prognostic Factors in Patients with Unruptured Vertebral and Basilar Fusiform Aneurysms Treated with Endovascular Procedures : A Single Center Retrospective Analysis

PURPOSE

Large vertebral and basilar fusiform aneurysms (VFA) are sometimes difficult to cure by endovascular treatment (EVT). We aimed to elucidate indicators of poor outcomes of EVT in patients with VFAs.

METHODS

Clinical data from 48 patients with 48 unruptured VFAs in the Hyogo Medical University were retrospectively analyzed. The primary outcome was defined as satisfactory aneurysm occlusion (SAO) according to Raymond-Roy grading scale. The secondary and safety outcomes were a modified Rankin scale (mRS) score of 0-2 at 90 days, retreatment, major stroke, and aneurysm-related death after EVT.

RESULTS

The EVT included stent-assisted coiling (n = 24; 50%), flow diverter (n = 19; 40%), and parent artery occlusion (n = 5; 10%). The SAO was less frequently observed in large or thrombosed VFAs at 12 months (64%, p = 0.021 and 62%, p = 0.014, respectively), especially when the aneurysms were both large and thrombosed (50%, p = 0.0030). Retreatment was more common in large aneurysms (29%, p = 0.034), thrombosed (32%, p = 0.011), and large thrombosed aneurysms (38%, p = 0.0036). Although the proportion of mRS 0-2 at 90 days and major stroke showed no significant differences, that of post-treatment rupture was significantly larger in large thrombosed VFAs (19%, p = 0.032). Aneurysm-related death occurred by aneurysm rupture and was more frequent in large thrombosed VFA (19%, p = 0.032). Multivariate analysis showed SAO at 12 months was less common (adjusted odds ratio, OR: 0.036, 95% confidence interval, CI 0.00091-0.57; p = 0.018), and retreatment was more common (adjusted OR 43, 95% CI 4.0-1381; p = 0.0012) in large thrombosed VFA.

CONCLUSION

The large thrombosed VFAs were associated with poor outcomes after EVT including flow diverter.

Endovascular treatment of intracranial vertebral artery dissecting aneurysm, a case series study with two years follow up on complications

Background

This study is aimed to analyze the clinical outcomes of endovascular treatments for patients with intracranial vertebral artery dissecting aneurysms.

Methods

Clinical data of 32 patients with vertebral artery dissecting aneurysms who underwent endovascular procedures in the Department of Neurosurgery of our University from January 2016 to December 2019 were retrospectively analyzed. Nine cases were treated with endovascular occlusion; 23 cases received reconstructive treatment, including 20 cases of stent combined with coil embolization, and 3 cases of stent implantation. The angiography taken at 3-22 months after surgery was reviewed.

Results

The endovascular treatments for all 32 cases were successful. Thirty-one cases had no postoperative complications during index hospital. Mid-term follow-up showed that: 27 cases (84%) had embolism; 5 cases (16%) had recurrence, of which 4 cases were treated again with endovascular procedures followed with no further complications and no recurrence, and 1 case received closely monitor but no reoperation. During an average follow-up of 10.5 months, except for one case that was self-discharged due to end-stage brainstem compression and respiratory failure, the rest of the patients were in stable conditions without bleeding or infarction.

Conclusion

Endovascular treatment of intracranial vertebral artery dissecting aneurysms is safe and effective. Recurrent vertebral artery dissecting aneurysms can be treated with endovascular reoperations with satisfactory outcomes.

Treatment of fusiform aneurysms with a pipeline embolization device: a multicenter cohort study

BACKGROUND

Intracranial fusiform aneurysms are less common than saccular aneurysms, but are associated with higher mortality and morbidity. We conducted this study to determine the safety and efficacy of the pipeline embolization device (PED) to treat intracranial fusiform aneurysms.

METHODS

This was a multicenter, retrospective, and observational study. Data for this study came from the PLUS study conducted from 2014 to 2019 across 14 centers in China. Univariate and multivariable logistic regression analyses were performed to evaluate predictors of the occlusion rate and complication.

RESULTS

A total of 1171 consecutive patients with 1322 intracranial aneurysms participated in this study. Among the participants, 104 patients with 109 fusiform aneurysms were eligible for this analysis (mean age 49 years, 36.5% women, aneurysm mean size 14.7 mm, 55% in the posterior circulation, and 6% in the basilar artery). Mean follow-up time was 9.0 months (range 3-36 months). The last DSA angiographic follow-up was available for 85 patients, and 58 aneurysms (68.2%) were completely occluded. The overall complication rate and mortality were 17.3% and 2.8%, respectively. Multivariate analysis demonstrated that age (OR=1.007, p=0.037) and cerebral atherosclerosis (OR=1.441, p=0.002) were associated with incomplete occlusion of fusiform aneurysms after PED treatment.

CONCLUSION

PEDs may be an effective treatment for intracranial fusiform aneurysms, with a favorable occlusion rate. However, because these treatments have a relatively high rate of complications, PED treatment for fusiform aneurysms should be carefully and strictly controlled. Our analysis showed that PEDs with adjunctive coiling did not significantly improve the occlusion rate of fusiform aneurysms.

Predictive Factors of Recurrence after Endovascular Treatment of Unruptured Vertebrobasilar Fusiform Aneurysms

PURPOSE

This study aimed to investigate the predictive factors of recurrence after endovascular treatment (EVT) for unruptured vertebrobasilar fusiform aneurysms (VBFA).

METHODS

This single-center retrospective study evaluated 36 patients who underwent EVT of unruptured VBFA between 2008 and 2020. Variables influencing recurrence, such as size, type, thrombus, preoperative symptoms, and treatment methods, were analyzed. All patients were followed up using vessel imaging.

RESULTS

In total, 7 of 36 patients (19.4%) developed recurrence. The mean time from EVT to recurrence was 9.2 months (range 2-26.9 months). Maximum aneurysmal diameter on magnetic resonance imaging was decreased, increased, and remained unchanged in 1, 7, and 28 patients, respectively. Transitional type VBFA, brain compression symptoms, large aneurysmal diameter and length, preoperative modified Rankin Scale (mRS) score ≥ 2, sole stenting technique, and intra-aneurysmal thrombus significantly influenced the risk of recurrence. Post-EVT, 7 (19.4%) patients showed complete occlusion of the aneurysm on the immediate postoperative angiogram, and 22 (61.1%) patients showed complete occlusion on the 1‑year follow-up imaging. Good outcomes were observed in 32 patients (88.9%) at the last follow-up, with a mRS score of 0-1 after EVT.

CONCLUSION

EVT achieves good outcomes in unruptured VBFA. Transitional type VBFA, brain compression symptoms, large aneurysmal diameter and length, preoperative mRS score ≥ 2, sole stenting technique, and intra-aneurysmal thrombus are risk factors for aneurysm recurrence after EVT.

Unruptured Intradural Posterior Circulation Dissecting/Fusiform Aneurysms Natural History and Treatment Outcome

BACKGROUND

The natural history and outcome of unruptured posterior circulation dissecting fusiform aneurysms is not fully understood. These have a high risk of morbidity and mortality, not only due to natural history but also due to the challenging and controversial treatment approaches currently available compared to other types of intracranial aneurysms.

METHODS

We performed a retrospective study of a prospectively collected aneurysm database at a quaternary neurovascular hospital. We included consecutive patients with unruptured intradural vertebrobasilar dissecting aneurysms between January 2000 and July 2016 who were followed to 2020. Description of baseline, procedural, and outcomes data was performed. Comparisons of patient who had aneurysm rupture on follow-up, increase in 2 or more points of mRS in follow-up and progression of the aneurysm was performed.

RESULTS

Seventy patients with 78 fusiform posterior circulation aneurysms were identified. Thirty-nine (55.7%) patients were male with a mean age of 51.7 years (SD ± 17.6). When multiple, aneurysms were more likely to be fusiform (60%) than saccular (40.0%). Baseline diameter (measured on CTA/MRA/DSA), length as well as symptomatic presentation were significantly higher in aneurysms which grew over time. Coronary disease, diabetes and growth were associated an >2 increase in mRS. Diabetes as well as initial symptomatic presentation were associated with rupture.

CONCLUSIONS

Unruptured dissecting/fusiform aneurysm are associated with a considerable rate of rupture during follow-up. Growth is associated with morbidity even in the absence of rupture. Initial large size, coronary disease, diabetes, and to a lesser extent female gender may merit closer follow-up and/or prophylactic treatment.

Prospects and Dilemmas of Endovascular Treatment for Vertebrobasilar Dolichoectasia

Vertebrobasilar dolichoectasia (VBD) is characterized by significant expansion, elongation, and tortuosity of the basilar artery and vertebral artery. Certain highly selected cases of VBD can require intervention. Recent advances in endovascular treatment (EVT) have renewed hope for patients with VBD. However, which cases of VBD can benefit from EVT still needs to be determined. Currently, little is known regarding this matter. Therefore, we performed a review of the literature from a PubMed search and cataloged our experience regarding the classification and natural history of VBD and the prospects, prognosis and complications of EVT. The findings can be summarized as follows: for asymptomatic VBD, “wait and see” or medical management may be a reasonable strategy. EVT may only be effective in certain patients. For saccular aneurysms in VBD, especially ruptured aneurysms, EVT is reasonable. For fusiform aneurysms in VBD, EVT can carry high complication rates and should be recommended with caution. For stenting reconstruction in VBD, the effect is uncertain. For the future of EVT of VBD, randomized controlled trials and the development of neurointerventional products are worth pursuing, but EVT in VBD still has a long way to go.

Endovascular Treatment of Large or Giant Basilar Artery Aneurysms Using the Pipeline Embolization Device: Complications and Outcomes

Background

This study aimed to investigate clinical and angiographic outcomes of Pipeline embolization device (PED) treatment of large or giant basilar artery (BA) aneurysms and examine associated factors.

Methods

Clinical and angiographic data of 29 patients (18 men, 11 women) with large or giant BA aneurysms were retrospectively examined. Mean age was 44.1 ± 21.2 years (range, 30–68). Mean aneurysm size was 22.2 ± 8.3 mm (range, 12.0–40.1).

Results

Mean angiographic follow-up was 18.3 ± 3.4 months (range, 4.5–60). The rate of adequate aneurysmal occlusion (O'Kelly–Marotta grade C–D) was 87%. The overall complication rate was 44.8%; most complications (84.6%) occurred in the periprocedural period. Univariable comparison of patients who did and did not develop complications showed significant differences in aneurysm size (p < 0.01), intra-aneurysmal thrombus (p = 0.03), and mean number of PEDs used (p = 0.02). Aneurysm size (odds ratio, 1.4; p = 0.04) was an independent risk factor for periprocedural complications in multivariable analysis. Mean clinical follow-up was 23.5 ± 3.2 months (range, 0.1–65). Nine patients (31%) had a poor clinical outcome (modified Rankin scale score ≥3) at last follow-up, including 7 patients who died. Univariable comparisons between patients with favorable and unfavorable clinical outcomes showed that aneurysm size (p = 0.009) and intra-aneurysmal thrombus (p = 0.04) significantly differed between the groups. Multivariable analysis showed that aneurysm size (odds ratio, 1.1; p = 0.04) was an independent risk factor for poor clinical outcome.

Conclusion

PED treatment of large or giant BA aneurysms is effective and can achieve a satisfactory long-term occlusion rate. However, the treatment complications are not negligible. Aneurysm size is the strongest predictor of perioperative complications and poor clinical outcome.

[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.

Isolated clival subdural haemorrhage from a dolicoectactic vertebrobasilar aneurysm: Case report and overview of endovascular treatment strategies

Posterior fossa aneurysms presenting with isolated subdural haemorrhage (SDH) have scarcely been described with no cases attributed to a vertebrobasilar (VB) location. Non-saccular VB aneurysms are a distinct sub-group and in this report we also discuss the pathophysiology and treatment options for these difficult-to-manage lesions. We present a case of a 49 year-old man who presented with a 7-day history of severe headaches who was found to have an isolated acute clival SDH. Vascular imaging revealed a VB dolicoectatic segment with superimposed fusiform dilatations that contacted the dura adjacent to the SDH. A staged treatment was performed with initial parental vessel occlusion of the ruptured vertebral artery segment and subsequent insertion of a braided stent (LEO) with flow diverting properties into the progressively dilating basilar artery. A third procedure was performed to occlude a recurrent pouch at the lower basilar dilatation. Complete angiographic occlusion was achieved and the patient is under continued surveillance. To our knowledge, this is the first case of a ruptured non-saccular VB aneurysm presenting with radiologically isolated clival SDH. Clinical history will often inform the need for vascular imaging in such atypical presentations. Managing these lesions remains an endovascular challenge and requires a specialist multi-disciplinary approach.

Melittin-loaded Iron Oxide Nanoparticles Prevent Intracranial Arterial Dolichoectasia Development through Inhibition of Macrophage-mediated Inflammation

Rationale: In intracranial arterial dolichoectasia (IADE) development, the feedback loop between inflammatory cytokines and macrophages involves TNF-α and NF-κB signaling pathways and leads to subsequent MMP-9 activation and extracellular matrix (ECM) degeneration. In this proof-of-concept study, melittin-loaded L-arginine-coated iron oxide nanoparticle (MeLioN) was proposed as the protective measure of IADE formation for this macrophage-mediated inflammation and ECM degeneration.

Methods: IADE was created in 8-week-old C57BL/6J male mice by inducing hypertension and elastase injection into a basal cistern. Melittin was loaded on the surface of ION as a core-shell structure (hydrodynamic size, 202.4 nm; polydispersity index, 0.158). Treatment of MeLioN (2.5 mg/kg, five doses) started after the IADE induction, and the brain was harvested in the third week. In the healthy control, disease control, and MeLioN-treated group, the morphologic changes of the cerebral arterial wall were measured by diameter, thickness, and ECM composition. The expression level of MMP-9, CD68, MCP-1, TNF-α, and NF-κB was assessed from immunohistochemistry, polymerase chain reaction, and Western blot assay.

Results: MeLioN prevented morphologic changes of cerebral arterial wall related to IADE formation by restoring ECM alterations and suppressing MMP-9 expression. MeLioN inhibited MCP-1 expression and reduced CD68-positive macrophage recruitments into cerebral arterial walls. MeLioN blocked TNF-α activation and NF-κB signaling pathway. In the Sylvian cistern, co-localization was found between the CD68-positive macrophage infiltrations and the MeLioN distributions detected on Prussian Blue and T2* gradient-echo MRI, suggesting the role of macrophage harboring MeLioN.

Conclusions: The macrophage infiltration into the arterial wall plays a critical role in the MMP-9 secretion. MeLioN, designed for ION-mediated melittin delivery, effectively prevents IADE formation by suppressing macrophage-mediated inflammations and MMP activity. MeLioN can be a promising strategy preventing IADE development in high-risk populations.

Endovascular treatment of type 1 and type 4 non-saccular aneurysms of cerebral arteries - a single-Centre experience

AIM OF THE STUDY

The aim of this study was to evaluate our results regarding treatment options, complications, and outcomes in patients with non-saccular aneurysms of cerebral arteries belonging to type 1 and type 4 according to Mizutani's classification.

METHODS

A total of 26 aneurysms in 26 patients were treated between 2014 and 2019. There were 13 males (mean age 42.77 ± 11.73 years) and 13 females (mean age 50.84 ± 9.37 years). In 23 cases the onset was haemorrhagic and in three cases non-haemorrhagic. A combination of conventional stents and coils was used in 10 cases, conventional stents and flow diverters in three cases, flow diverters and coils in five cases, and flow diverters only were used in eight cases. Radiological results of treatment were assessed after eight months and clinical after one year.

RESULTS

In 24 patients, aneurysms were occluded at the end of the follow-up period. An iatrogenic dissection and two haemorrhagic complications were registered. In three cases, parent arteries were occluded due to re-growth of the aneurysm, which caused middle cerebral artery infarction in one case. A favourable clinical outcome was registered in 19, patients, and non-favourable in five. Two patients died in the early postoperative period due to extensive damage to the brain parenchyma caused by initial bleeding.

CONCLUSION

Our results indicate that treatment of type 1 and type 4 non-saccular aneurysms with various combination of stents and flow diverters, with or without coils, is promising, although very challenging and technically demanding.

Expanding the Indications for Flow Diversion: Treatment of Posterior Circulation Aneurysms

Posterior circulation aneurysms are often associated with a higher risk of rupture and compressive symptoms compared to their anterior circulation counterpart. Due to high morbidity and mortality associated with microsurgical treatment of those aneurysms, endovascular therapy gained ascendance as the preferred method of treatment. Flow diversion has emerged as a promising treatment option for posterior circulation aneurysms with a higher occlusion rate compared to other endovascular techniques and a lower complication rate compared to microsurgery. While treatment of saccular and dissecting aneurysms is often associated with comparatively good outcomes, fusiform and dolichoectatic aneurysms should be carefully selected prior to treatment to avoid devastating thromboembolic complications. Occlusion of covered posterior circulation branches showed no correlation with ischemic complications, and appropriate antiplatelet regimen and switching Clopidogrel nonresponders to different antiplatelet agents were associated with lower complication rates following flow diversion of posterior circulation aneurysms.

Absence of pontine perforators in vertebrobasilar dolichoectasia on ultra-high resolution cone-beam computed tomography

Background

Vertebrobasilar dolichoectasia (VBDE) is a rare type of non-saccular intracranial aneurysm, with poor natural history and limited effective treatment options. Visualizing neurovascular microanatomy in patients with VBDE has not been previously reported, but may yield insight into the pathology, and provide important information for treatment planning.

Objective

To carry out a retrospective analysis of ultra-high resolution cone-beam computed tomography (UHR-CBCT) in patients with fusiform basilar aneurysms, visualizing neurovascular microanatomy of the posterior circulation with a special focus on the pontine perforators.

Methods

UHR-CBCT was performed in seven patients (mean age 59 years; two female) with a VBDE, and in 14 control patients with unrelated conditions.

Results

The mean maximum diameter of the fusiform vessel segment was 28 mm (range 19–36 mm), and the mean length of the segment was 39 mm (range 15–50 mm). In all patients with VBDE, UHR-CBCT demonstrated an absence of perforating arteries in the fusiform arterial segment and a mean of 3.7 perforators arising from the unaffected vessel segment. The network of interconnected superficial circumferential pontine arteries (brainstem vasocorona) were draping around the aneurysm sac. In controls, a mean of 3.6, 2.5, and 1.2 perforators were demonstrated arising from the distal, mid-, and proximal basilar artery, respectively.

Conclusions

The absence of pontine perforators in the fusiform vessel segment of VBDE is counterbalanced by recruitment of collateral flow from pontine perforators arising from the unaffected segment of the basilar artery, as well as collaterals arising from the anterior inferior cerebellar artery/posterior inferior cerebellar artery and superior cerebellar artery. These alternative routes supply the superficial brainstem arteries (brainstem vasocorona) and sustain brainstem viability. Our findings might have implications for further treatment planning.

Vertebrobasilar Dolichoectasia as a Rare Cause of Simultaneous Abducens and Vestibulocochlear Nerve Symptoms: A Case Report and Literature Review

Vertebrobasilar dolichoectasia (VBD) can lead to cranial nerve symptoms. However, multiple cranial nerve symptoms associated with VBD in one case remain extremely rare. We here present the case of a 33-year-old male with VBD diagnosed by multimodality imaging, who developed simultaneous abducens and vestibulocochlear nerve symptoms and subsequently improved after blood pressure control treatment. To our knowledge, this is the first report of such a vascular disorder resulting in simultaneous symptoms of the abducens and vestibulocochlear nerves. This study highlights that such a vascular anomaly should be considered when cranial nerve symptom is encountered, especially when multiple cranial nerves involved. Meanwhile, radiological evalurrrrrrrrrrrrrrrrrrration of such neurovascular conflict using three-dimensional constructive interference in steady-state imaging is recommended.

Sixth cranial nerve palsy secondary to compression by dolichoectatic vertebrobasilar artery

Dolichoectasia refers to distinct elongation, dilatation and tortuosity of an artery. We present a rare well-illustrated case of dolichoectatic vertebrobasilar artery compressing the cisternal portion of the sixth cranial nerve resulting in chronic sixth nerve palsy. High spatial resolution, three-dimensional, heavily T2-weighted MRI sequences are uniquely positioned to assess the cranial nerves especially in their cisternal and canalicular portions and need to be performed for all patients with non-resolving cranial nerve palsies. Dolichoectatic vessels can be the cause of neurovascular conflict and cause non-resolving oculomotor palsies.

Basilar artery dolichosis is associated with a poor 90-day outcome in acute isolated pontine infarction

Basilar artery (BA) dolichosis is not uncommon in patients with acute isolated pontine infarction. The effect of this abnormal BA geometrical form on the outcomes of pontine infarction has not been closely examined. This study aims to elucidate whether BA dolichosis contributes to a poor 90-day outcome in acute isolated pontine infarction. A total of 101 patients were enrolled with a median age of 65 years. The BA diameter (p = 0.026), basilar artery length (BAL) (p < 0.001), bending length (BL) (p < 0.001) and the proportion of BA bending (p < 0.001) were significantly higher in the BA dolichosis group. A poor outcome was closely associated with the baseline National Institute of Health Stroke Scale (NIHSS) score (p < 0.001), and BL (p = 0.042) as well as the proportions of BA dolichosis (p = 0.007) and BA bending (p = 0.010) in univariate analysis. Multivariate logistic regression analysis determined that BA dolichosis (adjusted OR = 4.724, 95% CI: 1.481~15.071, p = 0.009) and baseline NIHSS score (adjusted OR = 1.805, 95% CI: 1.296~2.513, p < 0.001) were independently associated with a poor outcome at 90 days. In conclusion, BA dolichosis may be a predictor of concern for a poor 90-day outcome in patients with acute isolated pontine infarction.

Morbidity and Mortality in Patients With Posterior Circulation Aneurysms Treated With the Pipeline Embolization Device: A Subgroup Analysis of the International Retrospective Study of the Pipeline Embolization Device

BACKGROUND

The safety of PipelineTM Embolization Device (PED; Medtronic Inc, Dublin, Ireland) in posterior circulation aneurysms is still controversial.

OBJECTIVE

To study complications associated with the treatment of posterior circulation aneurysms by conducting a subgroup analysis from the International Retrospective Study of PED registry.

METHODS

Data from 91 consecutive patients with 95 posterior circulation aneurysms at 17 centers between July 2008 to February 2013 were analyzed. The primary endpoint was defined as any complication leading to neurological morbidity or death. The outcome predictors were calculated using Kaplan-Meier and Cox regression methods.

RESULTS

The mean aneurysm size was 13.8 mm. Aneurysm types were saccular (36.8%), fusiform (29.5%), dissecting (28.4%), and others (5.3%). The median follow-up was 21.1 mo. Twelve (13.2%) patients encountered a primary endpoint event. In multivariate analysis for the primary endpoint, use of ≥3 PEDs and fusiform shape compared with other shapes had hazard ratios (HRs) of 7.77 (95% confidence interval [CI], 2.48-25.86; P = .0007) and 3.48 (95% CI, 1.06-13.39; P = .0488), respectively. The multivariate HR of aneurysm size for neurological morbidity after PED implantation was 1.11 (95% CI, 1.04-1.18; P = .0015), and HRs of ruptured aneurysm and age for neurological mortality were 8.1 (95% CI, 1.31-41.26; P = .0197) and 1.07 (95% CI, 1.02-1.15; P = .0262), respectively. Basilar artery aneurysm had an HR of 3.54 (95% CI, 1.12-14.18, P = .0529) in the univariate analysis for major outcomes.

CONCLUSION

PED implantation may be considered for the treatment of posterior circulation aneurysms, especially of saccular or dissecting type. Our major complications appear to be comparable to those reported previously after clipping and coiling in the literature. Neurointerventionists should consider the shape, size, rupture, and location of complex posterior circulation aneurysms as well as age and PED number before the PED placement.

Recurrent risk of ischemic stroke due to Vertebrobasilar Dolichoectasia

Background

Patients with vertebrobasilar dolichoectasia usually have persistent hemodynamic abnormalities, and therefore, may bear an increased risk of stroke. This study aimed to identify risk factors for stroke recurrence in patients with vertebrobasilar dolichoectasia.

Methods

Patients with acute ischemic stroke were screened and evaluated for eligibility. Enrolled patients were followed via scheduled clinical visits or telephone interviews. Ischemic stroke recurrence was proposed with clinical symptoms and confirmed with cranial Magnetic Resonance Imaging or Computerized Tomography scans. Baseline characteristics and vascular geometry were compared between patients with and without stroke recurrence. Significant parameters were introduced into COX proportional hazard model to detect possible predictors of stroke recurrence.

Results

A total of 115 stroke patients with vertebrobasilar dolichoectasia were enrolled, of which 22 (19.1%) had recurrence during 22 ± 6 months follow-up. Basilar artery diameter ≥ 5.3 mm (HR = 4.744; 95% CI, 1.718–13.097; P = 0.003), diffuse intracranial dolichoectasia (HR = 3.603; 95% CI, 1.367–9.496; P = 0.010) and ischemic heart disease history (HR = 4.095; 95% CI, 1.221–13.740; P = 0.022) had increased risk of recurrence.

Conclusions

Stroke patients with vertebrobasilar dolichoectasia may have a high risk of recurrence. Larger basilar artery diameter or diffuse intracranial dolichoectasia may increase the risk of recurrence.

The safety and efficacy of using large woven stents to treat vertebrobasilar dolichoectasia

OBJECTIVES

To characterize the safety and efficacy of large woven stents in the treatment of vertebrobasilar dolichoectasia (VBD).

METHODS

We retrospectively reviewed 19 consecutive patients with VBD treated with large woven intracranial stent (Leo stents) between January 2016 and December 2018. The clinical symptoms and angiograms of all the patients were recorded.

RESULTS

The patients were treated with 1-3 large Leo stents (5.5 mm x 75 mm, 5.5 mm x 50 mm, or 4.5 mm x 40 mm), with or without coiling. They had follow-up angiography and MRI between 3 months and 1 year. Digital subtraction angiography showed 16 patients with complete reconstruction of the target vessels, one patient with almost complete reconstruction, and two patients with partial reconstruction. All patients had symptomatic improvement shortly after treatment, but two patients developed recurrent dysphagia at 8 and 18 months, respectively.

CONCLUSIONS

Deployment of woven stents with or without supportive coiling may offer symptom relief and reconstruction in patients with VBD.

Intracranial arterial dolichoectasia and skull damage in a girl with Jaffe-Campanacci syndrome: a case report

ᅟJaffe-Campanacci is a rare syndrome characterised by axillary freckles, multiple non-ossifying fibromas of the long bones and jaw, and café-au-lait spots, associated with some features of neurofibromatosis type 1 (NF1). Cherix et al. and Colby and Saul suggested that Jaffe-Campanacci syndrome (JCS) might be a distinct form of NF1. Intracranial arterial dolichoectasia (IADE) is defined as an increase in the length and diameter of at least one intracranial artery. Affected intracranial arteries are dilated, elongated and sometimes tortuous. But in this rare disease of JCS, neither skull damage nor IADE has been previously reported. Here, we introduce the case of an 11-year-old Chinese girl with IADE, skull damage and features of JCS.

Pipeline Embolization of Vertebrobasilar Aneurysms—A Multicenter Case Series

BACKGROUND

The Pipeline Embolization Device (PED) has been increasingly used for the treatment of posterior circulation aneurysms. The purpose of the present study was to examine the clinical and angiographic outcomes of patients with vertebrobasilar aneurysms treated with the PED.

METHODS

We performed a retrospective review of vertebrobasilar aneurysms treated with the PED at 4 high-volume neurovascular centers. Patient, aneurysm, and procedural data were collected, including perioperative and delayed complications. Aneurysm occlusion on follow-up imaging studies was defined as complete (100%), near-complete (>90%), or incomplete (<90%) occlusion.

RESULTS

The cohort included 35 patients with 37 vertebrobasilar aneurysms who underwent 36 treatment sessions. Of the 35 patients, 10 were men (29%), and the mean patient age was 54.1 years (range, 32-75). Eight patients (23%) underwent urgent treatment because of a ruptured aneurysm (n = 6), brainstem perforator stroke (n = 1), or post-traumatic pseudoaneurysm (n = 1). Of the 37 aneurysms, 22 arose from the vertebral artery (59%) and 15 from the basilar artery (41%). Also, 19 were saccular aneurysms (51%), with a mean size of 7.7 mm (range, 1.7-38.0); 17 were fusiform aneurysms (46%), with a mean size of 11.0 mm (range, 4.3-34); and 1 was a 2.9-mm blister aneurysm. The overall procedural complication rate was 14% (5 of 36), including 3 neurologically symptomatic complications. At a mean follow-up period of 14 months (range, 3-59), 24 of 34 aneurysms (71%) were completely occluded and 29 of 34 (85%) were completely or near-completely occluded.

CONCLUSION

Our results show that Pipeline embolization of vertebrobasilar aneurysms is associated with acceptable occlusion and complication rates.

Radial Artery Access for Treatment of Posterior Circulation Aneurysms Using the Pipeline Embolization Device: Case Series

BACKGROUND

The treatment of selected wide-neck and fusiform posterior circulation aneurysms is challenging for clipping as well as for endovascular route.

OBJECTIVE

To describe an endovascular approach for vertebral artery aneurysm treatment using transradial access (TRA) instead of the conventional transfemoral access.

METHODS

We collected cases from two institutions in which TRA was used for posterior circulation Pipeline Embolization Device (Medtronic, Dublin, Ireland) deployment.

RESULTS

A total of four patients were treated. TRA was useful in the setting of extreme vessel tortuosity. We utilized 5F Terumo Glidesheath (Terumo Medical, Somerset, New Jersey), intermediate catheter, and a 027 microcatheter for Pipeline deployment. TRA was not associated with any access or deployment difficulties.

CONCLUSIONS

Early experience suggests that TRA for Pipeline Embolization Device placement for posterior circulation aneurysm is a safe and efficient alternative to standard transfemoral access. While this approach was initially applied to patients with vascular anatomy that may not allow for safe femoral access or navigation, experience so far argues for considering a radial approach towards some posterior circulation aneurysm treatment.

Sixth cranial nerve palsy and ipsilateral trigeminal neuralgia caused by vertebrobasilar dolichoectasia

Purpose

To report an unusual case of vertebrobasilar dolichoectasia causing both trigeminal neuralgia and ipsilateral sixth cranial nerve palsy.

Observations

A patient had undergone surgical decompression of trigeminal neuralgia caused by dolichoectatic vertebral and basilar arteries years before presenting with ipsilateral sixth nerve palsy. Brain MRI showed deviant vertebrobasilar arteries that presumably now compressed the sixth cranial nerve. The unaffected left sixth cranial nerve was visible on MRI, but the affected right sixth cranial nerve was not. The central spinal fluid space in Dorello's canal on the affected side was relatively ample, suggesting atrophy of the affected sixth cranial nerve. On follow-up examination one year after presentation, the patient's diplopia was palliated with spectacle prism.

Conclusions and importance

This is the tenth reported case of dolichoectasia causing sixth cranial nerve palsy, but only the second to occur with dolichoectatic trigeminal neuralgia. It provides more detailed imaging that previously reported cases. Review of reported cases of dolichoectatic compression of cranial nerves indicates that vascular decompression may be effective for trigeminal neuralgia, but is not indicated for dolichoectatic sixth nerve palsy, which will resolve spontaneously or can be effectively managed with prism or eye muscle surgery.

Hemodynamic characteristics of stable and unstable vertebrobasilar dolichoectatic and fusiform aneurysms

Background and purpose

Vertebrobasilar dolichoectatic and fusiform aneurysms (VBDAs) are known to have a poor natural history, with high rates of growth, rupture, and stroke. The purpose of this study was to identify hemodynamic characteristics that differ between VBDAs associated with growth, rupture, and stroke.

Materials and methods

VBDAs with CT angiography or MR angiography followed longitudinally without treatment were studied. Unstable aneurysms were defined as those that grew or ruptured during follow-up. Aneurysms associated with stroke were defined as those associated with posterior circulation infarct at follow-up. Baseline data, including demographics, comorbidities, and aneurysm morphology and size were collected. Image based computational fluid dynamics models were created and run under pulsatile flow conditions. Relevant hemodynamic and geometric variables were calculated and compared between groups (stable vs unstable and no stroke vs stroke) using the Wilcoxon test.

Results

A total of 37 VBDAs were included (24 stable, 13 unstable; 30 no stroke, 7 stroke). Unstable aneurysms had lower shear rates (P=0.05), blood flow velocity (P=0.03), and lower vorticity (P=0.049) than stable aneurysms. In addition, unstable aneurysms had higher mean oscillatory shear indices (P=0.001). There were no differences in the hemodynamic characteristics of aneurysms in the stroke group compared with the non-stroke group.

Conclusion

This small study suggests there may be hemodynamic differences between unstable and stable VBDAs. Unstable VBDAs appear to be under lower flow conditions with lower velocity, vorticity, and shear rates, and have more oscillatory flow. There was no difference in the hemodynamic characteristics of aneurysms in the stroke and no stroke group.

Efficacy and Outcomes of Posterior Inferior Cerebellar Artery (PICA) Bypass for Proximal PICA and Vertebral Artery-PICA Aneurysms: A Case Series

BACKGROUND

Nonsaccular vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms have high morbidity and mortality rates and are difficult to treat using standard microsurgical or endovascular techniques. Definitive revascularization can require clip trapping and/or vessel sacrifice, with PICA bypass. The published surgical experience with these approaches is limited. We herein review our recent surgical experience with PICA revascularization for complex PICA and VA/PICA aneurysms.

OBJECTIVE

To determine the efficacy and outcomes of PICA bypass for revascularization of nonsaccular PICA and VA/PICA aneurysms.

METHODS

Retrospective analysis of an institutional review board-approved, prospective database was performed to identify patients with PICA and VA/PICA aneurysms treated with PICA bypass at a single institution. Demographic information, aneurysm characteristics, temporary clip time, and neurological outcomes were recorded.

RESULTS

Ten cases of PICA revascularization were performed for both ruptured (n = 8) and unruptured (n = 2) nonsaccular proximal PICA or VA/PICA aneurysms. Seven cases were performed without vessel grafts; 3 cases required harvest of the descending branch of the lateral femoral circumflex artery. Mean temporary clip time was 38 min (range 27-50 min). Good outcomes (Glasgow Outcomes Scale score of 5) were achieved in 70% (n = 7) of patients at time of discharge; the remaining patients had a Glasgow Outcomes Scale of 3. Two bypass-related complications occurred in this series; a hematoma at the graft harvest site requiring evacuation, and severe bypass graft spasm requiring multiple endovascular treatments.

CONCLUSION

PICA bypass can be a safe, effective, and highly customizable tool for the revascularization of patients with nonsaccular proximal PICA and VA/PICA aneurysms.

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.

Meta-analysis of treatment outcomes of posterior circulation non-saccular aneurysms by flow diverters

INTRODUCTION

Non-saccular aneurysms of the posterior circulation are uncommon but highly dangerous lesions. Flow diverter stents have been demonstrated to be effective treatments of various anterior circulation aneurysms, particularly large and giant proximal internal carotid artery aneurysms. However, evidence regarding the treatment of non-saccular posterior circulation aneurysms with flow diverters is lacking.

METHODS

A systematic literature review of the English language literature since 2007 was conducted using PubMed, MEDLINE, and Embase. Keywords and MeSH terms included flow diversion, flow diverter, pipeline, surpass, intracranial aneurysm, vertebrobasilar, and non-saccular. Case reports were excluded. Angiographic and clinical outcomes were pooled using a random effects meta-analysis.

RESULTS

13 retrospective non-comparative studies reporting 129 patients and 131 aneurysm treatments were included. The average number of flow diverters per aneurysm was 4.33. Immediate complete or near complete occlusion of the aneurysm occurred in 25% (95% CI 1% to 60%), and long term occlusion in 52% (29-76%). Periprocedural stroke occurred in 23% of cases. Good long term neurologic outcome (modified Rankin Scale score ≤2) was achieved in 51% (95% CI 31% to 71%). Overall mortality was 21% (95% CI 7% to 38%) and morbidity was 26% (12%-42%). Retreatment was required in 5% (95% CI 0% to 14%). Good neurologic outcome rate was higher in vertebral artery aneurysms (83%) than other locations (18-33%).

CONCLUSIONS

Flow diversion is a feasible and efficacious treatment for non-saccular aneurysms in the posterior circulation. However, the intervention carries a significant risk of periprocedural stroke, and is still associated with high overall mortality. Further studies are needed to identify significant treatment risk factors and optimize patient selection.

Virtual endovascular treatment of intracranial aneurysms: models and uncertainty

Virtual endovascular treatment models (VETMs) have been developed with the view to aid interventional neuroradiologists and neurosurgeons to pre-operatively analyze the comparative efficacy and safety of endovascular treatments for intracranial aneurysms. Based on the current state of VETMs in aneurysm rupture risk stratification and in patient-specific prediction of treatment outcomes, we argue there is a need to go beyond personalized biomechanical flow modeling assuming deterministic parameters and error-free measurements. The mechanobiological effects associated with blood clot formation are important factors in therapeutic decision making and models of post-treatment intra-aneurysmal biology and biochemistry should be linked to the purely hemodynamic models to improve the predictive power of current VETMs. The influence of model and parameter uncertainties associated to each component of a VETM is, where feasible, quantified via a random-effects meta-analysis of the literature. This allows estimating the pooled effect size of these uncertainties on aneurysmal wall shear stress. From such meta-analyses, two main sources of uncertainty emerge where research efforts have so far been limited: (1) vascular wall distensibility, and (2) intra/intersubject systemic flow variations. In the future, we suggest that current deterministic computational simulations need to be extended with strategies for uncertainty mitigation, uncertainty exploration, and sensitivity reduction techniques. WIREs Syst Biol Med 2017, 9:e1385. doi: 10.1002/wsbm.1385 For further resources related to this article, please visit the WIREs website.

Surpass Flow Diverter for Treatment of Posterior Circulation Aneurysms

BACKGROUND AND PURPOSE

Flow diverters for the treatment of posterior circulation aneurysms remain controversial. We aimed to identify factors contributing to outcome measures in patients treated with the Surpass flow diverter for aneurysms in this location.

MATERIALS AND METHODS

We conducted an observational study of 53 patients who underwent flow-diverter treatment for posterior circulation aneurysms at 15 centers. Key outcome measures were mortality, complete aneurysm occlusion, and modified Rankin Scale score at follow-up.

RESULTS

At follow-up (median, 11.3 months; interquartile range, 5.9-12.7 months), 9 patients had died, resulting in an all-cause mortality rate of 17.3% (95% CI, 7%-27.6%); 7 deaths (14%) were directly related to the procedure and none occurred in patients with a baseline mRS score of zero. After adjusting for covariates, a baseline mRS of 3-5 was more significantly (P = .003) associated with a higher hazard ratio for death than a baseline mRS of 0-2 (hazard ratio, 17.11; 95% CI, 2.69-109.02). After adjusting for follow-up duration, a 1-point increase in the baseline mRS was significantly (P < .001) associated with higher values of mRS at follow-up (odds ratio, 2.93; 95% CI, 1.79-4.79). Follow-up angiography in 44 patients (median, 11.3 months; interquartile range, 5.9-12.7 months) showed complete aneurysm occlusion in 29 (66%; 95% CI, 50.1%-79.5%).

CONCLUSIONS

Clinical results of flow-diverter treatment of posterior circulation aneurysms depend very much on patient selection. In this study, poorer outcomes were related to the treatment of aneurysms in patients with higher baseline mRS scores. Angiographic results showed a high occlusion rate for this subset of complex aneurysms.

Treatment of posterior circulation non-saccular aneurysms with flow diverters: a single-center experience and review of 56 patients

BACKGROUND AND PURPOSE

Non-saccular aneurysms of the posterior fossa are an uncommon pathology with no clear treatment strategy. The use of flow-diverting stents (FDS) has had mixed results. We sought to evaluate our experience of FDS for the treatment of this pathology.

METHODS

We retrospectively reviewed our database of prospectively collected information for all patients treated only with flow diversion for an unruptured non-saccular aneurysm of the posterior circulation between February 2009 and April 2016. The aneurysms were classified as dolichoectasia, fusiform or transitional, and imaging characteristics including maximal diameter, disease vessel segment, MRI features (intra-aneurysmal thrombus, T1 hyperintensity in the aneurysmal wall, infarctions in the territory of the posterior circulation, and mass effect) were recorded alongside clinical and follow-up data.

RESULTS

We identified 56 patients (45 men) with 58 aneurysms. The average age of the patients was 63.5 years. Twenty-two patients were symptomatic from the aneurysms at presentation. The majority of the lesions were vertebrobasilar in location (44.8%) with isolated vertebral lesions representing 29.3% of aneurysms. Transitional aneurysms were the most common (48.2%). The mean maximal diameter of the aneurysms was 11 mm. Angiographic exclusion of the aneurysms was seen in 57.4% of aneurysms with follow-up (n=47). During the follow-up period nine patients died.

CONCLUSIONS

Treatment of non-saccular aneurysms of the posterior fossa is technically possible. Early treatment, particularly of the fusiform and transitional subtypes, is recognized, as is treatment prior to the development of symptoms. A 'watch and wait' strategy with regular imaging follow-up could be employed for asymptomatic dolichoectasia.

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.

Pathophysiology, presentation, prognosis, and management of intracranial arterial dolichoectasia

Up to 12% of patients with stroke have intracranial arterial dolichoectasia (IADE) and the basilar artery is affected in 80% of these cases. Diagnostic criteria and prognosis studies of IADE are based on basilar artery diameter, which is a good quantitative marker for the severity of the disease. The pathophysiology is largely unknown, but IADE can be viewed as a common final pathway of arterial wall response or damage in the tunica media due to various mechanisms, such as matrix metalloproteinase dysfunction or muscle cell or elastic fibre injury. No randomised controlled trials have been undertaken in IADE and thus little high-level evidence is available on which to base treatment guidelines. IADE management depends on clinical presentation and disease severity, and includes blood pressure control, antithrombotic treatments, endovascular procedures, and surgery. Further studies are needed to better define IADE in the general population, to establish its prevalence and pathophysiology, to identify subgroups at risk of life-threatening complications, and to offer effective treatment options.

Treatment of vertebrobasilar fusiform aneurysms with Pipeline embolization device

OBJECT

Treatment of complex intracranial aneurysms with Pipeline embolization device (PED) (ev3/Covidien Vascular Therapies) has gained recent popularity. One application of PEDs that is not well described in the literature is the utility and long-term safety in treatment of vertebrobasilar fusiform (VBF) aneurysms. Despite the advancements in endovascular therapy, VBF aneurysms continue to challenging pathology. The authors provide long-term follow-up of VBF aneurysms treated with PEDs.

METHODS

We retrospectively reviewed four patients that were treated at Louisiana State University Health Sciences Center in Shreveport with PEDs for VBFs from 2012 to 2014. Each patient was discussed in a multidisciplinary setting between neurosurgeons and neurointerventionalists. Each patient underwent platelet function tests to ensure responsiveness to anti-platelet agents and was treated by one neurointerventionalist (HC). All patients were placed on aspirin and Plavix and were confirmed for therapeutic response prior to discharge.

RESULTS

Follow-up ranged from 12 to 25 months, with a mean of 14.25 months. Two cases presented with a recurrence after the initial treatment, both of which required subsequent treatment. Of the four patients treated, one patient developed hemiparesis and three died.

CONCLUSION

Despite reports describing successful treatment of VBF aneurysms with PEDs, delayed complications after obliteration and remodeling can occur. We describe our institutional experience of VBFs treated with PEDs. Treatment of holobasilar fusiform aneurysms may carry a worse prognosis after treatment. Further long-term follow-up will provide a better understanding of this pathology.

Natural history and outcome after treatment of unruptured intradural fusiform aneurysms

BACKGROUND AND PURPOSE

Management of unruptured fusiform intracranial aneurysms is controversial because of the paucity of natural history data. We studied their natural history and outcome after treatment.

METHODS

We reviewed our neurovascular database from January 2000 to October 2013. Inclusion criteria were unruptured, intradural fusiform aneurysms with a diameter of <2.5 cm. Criteria were developed to define atherosclerotic aneurysms. For outcome assessment, we used the modified Ranking Scale and aneurysm measurements on serial imaging. Mann-Whittney (continuous) and Fisher exact (categorical) tests were used for risk factor analysis.

RESULTS

For nonatherosclerotic aneurysms (96 patients; 193 person-years follow-up), 1 patient died (rupture) during follow-up (mortality, 0.51% per year) and 8 patients (10%) showed aneurysm progression (risk, 1.6% per year). Risk factors for progression were maximum diameter (>7 mm; odds ratio, 12; 95% confidence interval, 1.4-104) and symptomatic clinical presentation (odds ratio, 16; 95% confidence interval, 3.1-81.4). Of the 23 treated patients, 3 had died (mortality, 12.5%) and 3 had serious disability (modified Ranking Scale, ≥3; 12.5%). For the atherosclerotic aneurysms (25 patients; 97 person-years follow-up), 5 had died (mortality, 5.2% per year) and 13 of 20 (65%) had aneurysm progression (risk, 12% per year). When compared with patients with nonatherosclerotic aneurysms, case fatality (odds ratio, 19.2; 95% confidence interval, 2.1-172) and aneurysm progression (odds ratio, 17.8; 95% confidence interval, 5.3-56) were higher.

CONCLUSIONS

Nonatherosclerotic fusiform intradural aneurysms have a low risk of adverse outcome within the first few years after diagnosis and remain stable unless symptomatic on presentation or >7 mm in maximum diameter. High risks of treatment should be balanced against this benign natural history. Atherosclerotic aneurysms have a worse natural history and may represent a different disease entity.