Cerebral arteriovenous malformations associated with flow-related and circle of Willis aneurysms

The influence of hemorrhage presentation on clinical outcomes of curative embolisation in 125 cerebellar arteriovenous malformations

BACKGROUND

This study investigated the influence of periprocedural hemorrhage and clinical outcomes with an endovascular therapeutic strategy for cerebellar arteriovenous malformations (cAVMs).

METHODS

From December 2006 to January 2018, 125 cAVMs were classified as types I-IV and received endovascular embolization via Onyx or Glubran 2. The risk factors of hemorrhage were analyzed using univariate and multivariate logistic analyses. A modified Rankin Scale (mRS) score was used to evaluate the neurological function before and 1 year after the operation. Results Of 125 patients, 63 had type I cAVMs, 2 type II cAVMs, 48 type III cAVMs, and 12 type IV cAVMs. A total of 88 (70.4%) patients had clinical manifestations of intracranial hemorrhage. Multivariate logistic regression analysis showed that age (OR, 2.276; 95% CI, 1.132 - 5.663), flow-related aneurysm (OR, 2.845; 95% CI, 1.265 - 6.248), lesion size (OR, 3.005; 95% CI, 1.119 - 5.936), and the number of feeding arteries (OR, 0.105; 95% CI, 0.081 - 0.312) were still the significant independent risk factors of intracranial hemorrhage. During a 1-year follow-up, 109 patients (87.2%) had good outcomes (mRS 0 - 2), 12 patients (9.6%) had poor outcomes (mRS 3 - 4), 4 patients (3.2%) died, and 3 patients had intracranial hemorrhage due to the incomplete embolization of cAVMs.

CONCLUSIONS

Endovascular embolization is a feasible treatment for cAVMs. Age, flow-related aneurysm, lesion size, and the number of feeding arteries are the significant risk factors of periprocedural hemorrhage. Moreover, the lesion characteristics must be given full consideration when using Onyx or Glubran 2 before cAVMs embolization.

Solid vs. cystic predominance in posterior fossa hemangioblastomas: implications for cerebrovascular risks and patient outcome

BACKGROUND

Hemangioblastomas (HGBs) are highly vascular benign tumors, commonly located in the posterior fossa, and 80% of them are sporadic. Patients usually present with features of raised intracranial pressure and cerebellar symptoms. HGB can be classified as either mostly cystic or solids. Although the solid component is highly vascularized, aneurysm or hemorrhagic presentation is rarely described, having catastrophic results.

METHODS

We identified 32 consecutive patients with posterior fossa HBG who underwent surgery from 2008 through 2020 at our medical center. Tumors were classified as predominantly cystic or solid according to radiological features. Resection was defined as gross total (GTR) or subtotal (STR).

RESULTS

During the study period, 32 posterior fossa HGBs were resected. There were 26 cerebellar lesions and 4 medullar lesions, and in 2 patients, both structures were affected. Predominant cystic tumors were seen in 15 patients and solids in 17. Preoperative digital subtraction angiography (DSA) was performed in 8 patients with solid tumors, and 4 showed tumor-related aneurysms. Embolization of the tumors was performed in 6 patients, including the four tumor-related aneurysms. GTR was achieved in 29 tumors (91%), and subtotal resection in 3 (9%). Three patients had postoperative lower cranial nerve palsy. Functional status was stable in 5 patients (16%), improved in 24 (75%), and 3 patients (9%) deteriorated. One patient died 2 months after the surgery. Two tumors recurred and underwent a second surgery achieving GTR. The mean follow-up was 42.7 months (SD ± 51.0 months).

CONCLUSIONS

Predominant cystic HGB is usually easily treated as the surgery is straightforward. Those with a solid predominance present a more complex challenge sharing features similar to arteriovenous malformations. Given the important vascular association of solid predominance HGB with these added risk factors, the preoperative assessment should include DSA, as in arteriovenous malformations, and endovascular intervention should be considered before surgery.

Acute Subdural Hematomas in Ruptured Brain Arteriovenous Malformations: Association with Distal Flow-Related Aneurysms

PURPOSE

Non-traumatic acute subdural hematomas (SDH) are rare and have seldom been reported in ruptured brain arteriovenous malformations (BAVM). The aim of this study was to report the frequency of acute SDH in BAVM-related hemorrhage and to determine the relationship of SDHs with BAVM angioarchitectural features.

METHODS

This was a retrospective monocentric study of patients admitted for BAVM rupture between 2003 and 2017. Patients with rupture complicating or closely following partial embolization procedures were excluded. Univariate followed by multivariate logistic regression analysis was used to determine factors significantly and independently associated with SDHs and distal flow-related aneurysms.

RESULTS

A total of 181 patients with 188 BAVM ruptures admitted during the study period were included, eleven cases of acute SDH were identified (6%) and 2 cases of isolated SDH were found. The presence of a distal flow-related aneurysm was the only feature independently and significantly associated with SDH (odds ratio [OR] 8.1, 95% confidence interval, CI 1.9-34.5, P = 0.003). Distal flow-related aneurysms were associated with proximal flow-related aneurysms (OR 28, 95%CI 4.9-163.8, P < 0.001), were more frequent in infratentorial BAVMs (OR 3.7, 95%CI 1.3-10.2, P = 0.01) and more often found in cases of acute SDH (OR 16.9, 95%CI 3.6-79.6, P < 0.001) and subarachnoid hemorrhage (SAH) (OR 4.5, 95%CI 1.7-12.2, P = 0.003).

CONCLUSION

Ruptured BAVMs can rarely present with acute SDH and SDH in ruptured BAVMs are often associated with distal flow-related aneurysms. This finding may impact acute management of ruptured BAVMs with SDH by eliciting an emergent and thorough imaging work-up to identify distal flow-related aneurysm(s), in turn leading to treatment.

Early Rebleeding after Brain Arteriovenous Malformation Rupture, Clinical Impact and Predictive Factors: A Monocentric Retrospective Cohort Study

Background: Brain arteriovenous malformations (BAVMs) are a leading cause of intracranial hemorrhage in young adults. This study aimed to identify individual predictive factors of early rebleeding after BAVM rupture and determine its impact on prognosis. Methods: Early rebleeding was defined as a spontaneous intracranial hemorrhage within 30 days of BAVM rupture in patients with nonobliterated BAVMs. One hundred fifty one patients with 158 BAVM hemorrhagic events admitted to a tertiary care center during 14 years were included. Univariate followed by multivariate logistic regression was performed to assess the impact of early rebleeding on in-hospital mortality and modified Rankin Scale (mRS) score beyond 3 months and to identify independent predictors of early rebleeding. Results: Eight early rebleeding events were observed, 6 of which occurred during the first 7 days. Early rebleeding was independently and significantly associated with poor outcome (mRS ≥3 beyond 3 months, p = 0.004) but not with in-hospital mortality (p = 0.9). Distal flow-related aneurysms (p = 0.009) and altered consciousness with a Glasgow coma scale score of 3 (p = 0.01) were independently associated with early rebleeding. Conclusions: Early rebleeding is a severe complication that can occur after BAVM-related hemorrhage. Distal flow-related aneurysms and initial altered consciousness are associated with early rebleeding.

Endovascular treatment of arteriovenous malformations

Cerebral arteriovenous malformations (AVM) are tangles of blood vessels that permit shunting of blood from the arterial to venous phase without intervening capillaries. The malformation's arterialization of a low-pressure system creates a risk of rupture that is substantially higher when associated with an aneurysm. The annual hemorrhage rate is 2.2% per year as reported in the randomized trial of unruptured brain AVMs (ARUBA; rupture risk is increased after the first event. Ruptured AVMs have a 10% mortality rate and 20%-30% morbidity rate. The treatment of choice for AVMs is microvascular resection with or without preoperative embolization. Surgical risk can be stratified based on the Spetzler-Martin grading system. Liquid embolic material and coils may be used for the treatment of AVM associated aneurysms, especially in the setting of acute rupture as a bridge to delayed surgical resection. There is some limited reported success in total endovascular treatment of AVMs, but this is not considered standard therapy at this time. Stereotactic radiosurgery (SRS) has been recently described but mainly limited to AMVs deemed too risky to approach in an open fashion and limited to 2.5cm-3cm in size. The delayed protection from hemorrhage (approximately 2-3 years) and high marginal failure/recurrence rate are the greatest concerns.

Patient Age, Hemorrhage Patterns, and Outcomes of Arteriovenous Malformation

BACKGROUND

The angioarchitecture and presentation of arteriovenous malformations (AVMs) associated with AVM hemorrhage may vary with patient age. Our aim was to determine the influence of patient age at diagnosis on hemorrhage patterns and outcomes.

METHODS

A consecutive case series of 267 cases of ruptured AVMs was retrospectively analyzed. Hemorrhage patterns (intracerebral hemorrhage, subarachnoid hemorrhage, and intraventricular hemorrhage) were confirmed based on computed tomography imaging at initial diagnosis. Clinical outcomes were classified with a modified Rankin Score. These cases were analyzed with respect to age at diagnosis, hemorrhage patterns, Spetzler-Martin grades, and their clinical outcomes.

RESULTS

During a mean 22.2 months follow-up time (range, 7 hours to 10 years), 212 cases (79.4%) were favorable (modified Rankin Score ≤2) and 55 cases (21.6%) were unfavorable (modified Rankin Score ≥3). The mean age was higher in patients with an unfavorable outcome at follow-up. In univariate analyses, different age groups were significantly associated with bleeding patterns (P = 0.022). Unfavorable outcome was associated with intracerebral hemorrhage (odds ratio, 0.330; 95% confidence interval, 0.142-0.768; P = 0.008) and evacuation of hematoma (odds ratio, 0.195; 95% confidence interval, 0.044-0.867; P = 0.025), whereas intraventricular hemorrhage, subarachnoid hemorrhage, and intraventricular drainage were significantly associated with a favorable outcome. Different age groups were not significantly associated with bleeding patterns, sex, and the location of the AVM, and Spetzler-Martin grades did not show a significant association with the severity of outcomes.

CONCLUSIONS

Different age groups were significantly associated with bleeding patterns. Higher patient age, intracerebral hemorrhage, and evacuation of hematoma seem to be associated with an unfavorable outcome after AVM rupture.

Frequency, risk of hemorrhage and treatment considerations for cerebral arteriovenous malformations with associated aneurysms

BACKGROUND

Data on arteriovenous malformations (AVMs) of the brain with AVM-associated aneurysms (AAA) are scarce. This study addresses the incidence, rate of hemorrhage, treatment strategies and stability during follow-up in a neurovascular center.

METHODS

We retrospectively reviewed patients harboring an AVM with at least one AAA treated at our neurovascular center between 2002 and 2013.

RESULTS

Of 216 patients, 59 (27.3%) had at least one AAA (n = 92 aneurysms total). Compared to patients without AAA, hemorrhagic presentation occurred more frequently (61.0% versus 43.9%, p = 0.025), and the rate of infratentorial AVMs was higher (37.3% versus 16.6%, p = 0.001). The aneurysm was the origin of the bleeding in most cases, most often categorized as a feeding artery aneurysm. Overall, the first and recurrent hemorrhage were associated with a high mortality and morbidity (15.3% and 39%, respectively). Aneurysms were treated by coiling (n = 21), surgery (n = 18), or embolizaton with liquid embolization agents (n = 11). All aneurysms treated by embolization and surgery remained occluded during follow-up (mean follow-up 39.0 ± 45.0 months). However, in incomplete AVM obliteration, significant recurrence of the treated aneurysm was noted after endovascular coiling (37.5%), which may be related to the persistence of pathological blood flow.

CONCLUSION

In our series, AAA was a significant risk factor for hemorrhage and was associated with a poor outcome. It seems worthwhile to consider whether the aneurysm itself is a risk factor or only an epiphenomenon of severely altered hemodynamics induced by these special AVMs and therefore only the most common site of rupture. As the complication rate was low for aneurysm occlusion, we recommend treating these aneurysms whenever possible. Furthermore, obliteration of the AVM should be strived for as this subtype may be associated with an increased risk of hemorrhage.

Successful treatment of a ruptured flow-related aneurysm in a patient with hemangioblastoma: Case report and review of literature

Background:

No cerebral aneurysms on the feeder associated with hemangioblastomas that ruptured before resection have been reported. We report a patient with a ruptured flow-related aneurysm associated with cerebellar hemangioblastoma and a tumor feeder treated simultaneously by a single procedure of embolization using N-butyl cyanoacrylate before tumor removal.

Case Description:

A 36-year-old female with a cerebellar tumor was admitted to our institute. Four days later, she suffered a massive subarachnoid hemorrhage mainly in the posterior fossa. Left vertebral angiograms showed an aneurysm on the feeding artery, posterior inferior cerebellar artery. Both the aneurysm and its main feeder were simultaneously treated by a single procedure of embolization using N-butyl cyanoacrylate. Their complete obliteration was confirmed angiographically. Four days after the procedure, we removed the tumor and the embolized aneurysm. The pathological diagnosis was hemangioblastoma and flow-related ruptured aneurysm.

Conclusion:

Cerebral angiography should be performed to rule out vascular abnormalities such as cerebral aneurysms adjacent to the tumor in patients with hemangioblastoma who present with intracranial hemorrhage. We emphasize the usefulness of embolization with N-butyl cyanoacrylate for hemangioblastoma with ruptured feeder aneurysm, by which the aneurysm and the feeder could be simultaneously embolized.

Secondary histomorphological changes in cerebral arteries of normotensive and hypertensive rats following a carotid-jugular fistula induction

Haemodynamic changes in cerebral circulation are associated with the natural ageing process and associated pathology, leading to the development of incapacitating neurological and neurovascular diseases. Due to inherent biological limitations, current literatures mostly aimed at studying the correlation descriptively or quantifying the relationship in vitro or using computational models. In this paper, a model of a carotid-jugular fistula in the rat was used to create a haemodynamic insult to the intracranial arterial circulation and subsequent venous drainage. An arterial-venous (AV) fistula was created in 12 rats, 6 of which are normotensive Wistar-Kyoto strain (WKY) and the rest spontaneously hypertensive strain (SHR) with an additional 6 in each strains designed as controls without previous surgery. After 4 weeks of convalescence, all 24 rats were euthanised and their cerebral circulation was examined histomorphologically. We confirmed an intrinsic morphological difference between normotensive WKY and hypertensive SHR and found a modest but significant arterial shrinkage in both strains induced with AV fistula. We also reported that alterations in blood flow are also associated with marked extracellular matrix changes. We concluded that the model was suitable for studying the relative contributions of altering haemodynamic patterns and venous drainage on cerebrovascular changes. We also found that hypertension modulated cerebral vascular changes in addition to disrupted blood flow.

A rare association of cerebral dural arteriovenous fistula with venous aneurysm and contralateral flow-related middle cerebral artery aneurysm

The association of cerebral dural arteriovenous fistula (DAVF) and ipsilateral flow related aneurysm has infrequently been reported. We describe a male patient who presented with an acute haemorrhagic stroke and was found to have a large right fronto-parietal intra-parenchymal haemorrhage from the ruptured Borden type II DAVF in addition to a large venous aneurysm and a flow related intraosseous aneurysm of the contralateral middle meningeal artery (MMA) all clearly delineated by CT and DSA. He underwent emergency stereotactic evacuation of the intraparenchymal haemorrhage and successful surgical treatment of all the vascular lesions at the same time with residual neurological deficit. To our knowledge, this is the first such reported case. We discuss the challenging surgical treatment, emphasising the role of CT/DSA in management, and provide a literature review.