Multiple anterior inferior cerebellar artery aneurysms associated with an arteriovenous malformation: case report

Anterior inferior cerebellar artery (AICA) aneurysms: a radiological study of 15 consecutive patients

Introduction

The aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions of the posterior circulation and to treat them is challenging. We aim to present anatomical and morphological characteristics of AICA aneurysms in a series of 15 patients.

Method

The DSA and CT angiography images of AICA aneurysms in 15 consecutive patients were analyzed retrospectively. Different anatomical characteristics were quantified, including morphology, location, width, neck width, length, bottleneck factor, and aspect ratio.

Results

Eighty percent of the patients were females. The age was 52.4 ± 9.6 (mean ± SD) years. 11 patients were smokers. Ten patients had a saccular aneurysm and five patients had a fusiform aneurysm. Aneurysm in 10 patients were located in the proximal segment, in three patients in the meatal segment, and in two patients in the distal segment. Ten out of 15 patients presented with a ruptured aneurysm. The size of AICA aneurysms was 14.8 ± 18.9 mm (mean ± SD). The aspect ratio was 0.92 ± 0.47 (mean ± SD) and bottleneck factor was 1.66 ± 1.65 (mean ± SD).

Conclusion

AICA aneurysms are rare lesions of posterior circulation predominantly found in females, present predominantly with subarachnoid hemorrhage, and are mostly large in size.

Treatment and Outcome of Anterior Inferior Cerebellar Artery (AICA) Aneurysms: Helsinki Series of 15 Consecutive Patients

Objective Anterior inferior cerebellar artery (AICA) aneurysms are rare posterior circulation lesions that are challenging to treat. This article presents the treatment and clinical outcome of AICA aneurysms in an unselected cohort of patients.

Methods A retrospective analysis of patient record files, digital subtraction angiography, and computed tomography angiography images of 15 consecutive patients harboring AICA aneurysms treated between 1968 and 2017.

Results Of the 15 AICA aneurysm patients reviewed, 12 (80%) were females. Twenty percent had intracerebral hemorrhage and 40% presented with intraventricular hemorrhage. Eleven out of 15 (73%) patients presented with subarachnoid hemorrhage (SAH); 82% of SAH patients had a good-grade SAH (Hunt and Hess grade 1–3). Eleven patients (73%) were treated surgically, three (20%) were treated conservatively, and one (7%) had coil embolization. In 27% of patients, a subtemporal approach with anterior petrosectomy was performed. A retrosigmoid approach was used in the remaining 73%. In 18% of the patients, a parent vessel occlusion was necessary to occlude the aneurysm. Five out of 11 (47%) of the patients developed postoperative cranial nerve deficits. Twenty-seven percent developed shunt-dependent hydrocephalus. All patients who presented with an unruptured AICA aneurysm had good clinical outcome (modified Rankin scale [mRS] 1–2). In patients with SAH, 82% achieved good clinical outcome and 18% had poor clinical outcome (mRS 3–6) after 1 year.

Conclusion Surgical treatment of AICA aneurysms has a high rate of cranial nerve deficits but most of patients have a good long-term clinical outcome.

Distal Aneurysms of Cerebellar Arteries-Case Series

(1) Background: Distal aneurysms of cerebellar arteries are very rare. The authors report their case series of distal aneurysms of the cerebellar arteries solved successfully by microsurgery or by endovascular treatment (Table 1) (2) Materials and Methods: Between January 2010 and March 2020, 346 aneurysms were treated in our institution. Eleven aneurysms in seven patients were located on distal cerebellar arteries and, in three patients, the aneurysms were combined with arteriovenous malformations. There were four women and three men, ranging from 50 to 72 years of age. Five patients presented with different grades of subarachnoid hemorrhage or intraventricular bleeding, and two patients were diagnosed because of headache. Aneurysm location was the posterior inferior cerebellar artery in six cases, the superior cerebellar artery in three cases, and the anterior inferior cerebellar artery in 2 cases. One patient had three aneurysms, and two patients had two aneurysms. (3) Results: Nine aneurysms were treated by microsurgery trapping or clipping and, in two patients, the associated arteriovenous malformation (AVM) was resected. Two aneurysms were treated by endovascular coiling, and one associated AVM was successfully embolized. Clinical follow-up was a mean of 11.5 months (range, 3-45 months). (4) Conclusion: The authors present their experience with the treatment of 11 peripheral aneurysms on distal branches of the cerebellar circulation in seven patients which were excluded from circulation by microsurgery or endovascular treatment. In three patients, the associated AVM was treated (two with microsurgery, one with embolization).

Pure Endovascular Management of an Arteriovenous Malformation and an Aneurysm Both Supplied by Anterio-Inferior Cerebellar Artery: A Case Report and a Review of Literature

Background and importance

The tendency of posterior fossa arteriovenous malformations (pfAVM) to develop associated aneurysms (AA) is a well-known phenomenon with an increased total risk of rupture. Most pfAVM and AA develop in the territory of the posterior inferior cerebellar artery while the involvement of the anterior inferior cerebellar artery (AICA) is extremely rare. We describe an unusual case of an arteriovenous malformation (AVM) supplied by the AICA with a “proximal” AA. This unique combination of vascular lesions has been reported in only four cases so far, limiting the available experience that can safely guide the therapeutic intervention.

Clinical presentation

This study describes a 59-year-old female presented with a subarachnoid hemorrhage, Hunt and Hess grade 4. Angiography demonstrated an AVM fed mainly by the right AICA and draining superficially into the transverse sinus (Spetzler–Martin grade II). In addition, there was a ruptured proximal AICA aneurysm. An endovascular approach was chosen to coil the aneurysm and obliterate the AVM using ONYX in a multi-staged process. The patient recovered well without residual deficit at 6-month follow-up.

Conclusion

To the best of our knowledge, this is the first report describing a proximal AICA aneurysm and AVM treated by endovascular means. The outcome was very good, considering the technically demanding location. All previously reported cases with exactly similar lesions were managed surgically, with inconclusive outcomes. The data presented in this study are meant to help in decision-making process for similar cases till more data are available.

Endovascular treatment of AICA flow dependent aneurysms. A report of three cases and review of the literature

Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare, accounting for less than 1% of all cerebral aneurysms. To our knowledge 34 flow-related cases including the present study have been reported in the literature. Three patients harbouring four flow dependent aneurysms were referred to our institution. Two patients presented with subarachnoid hemorrhage, one presented with cerebellar manifestations. They were all treated by endovascular embolization of the aneurysm as well as the parent artery using liquid embolic material. Two cases were embolized using NBCA, Onyx was used in the third case. No bleeding or rebleeding were encountered during the follow-up period which ranged from five to nine months. One patient developed facial palsy, cerebellar symptoms and sensorineural hearing loss. The remaining two cases did not develop any post treatment neurological complications. Endovascular management of flow-dependent AICA aneurysms by parent artery occlusion is feasible and efficient in terms of rebleeding prevention. Post embolization neurological complications are unpredictable. This depends upon the adequacy of collaterals from other cerebellar arteries.

Endovascular treatment of cerebral aneurysms associated with arteriovenous malformations

BACKGROUND AND PURPOSE

In univariate survival analysis, coexisting aneurysms was associated with a significantly increased risk of hemorrhage in AVMs. We report here on our clinical experience with AVMs associated with arterial aneurysms that were managed by endovascular treatment.

METHODS

To determine the incidence of associated aneurysms, the authors reviewed 366 consecutive patients with AVMs managed between 1999 and 2009. In 86 (23.5%) of these 366 patients, 55 intranidal aneurysms and 40 proximal aneurysms were observed. Targeted endovascular treatment with coils, n-butylcyanoacrylate(NBCA) and Onyx was performed for patients in this series, using a standard protocol. We reviewed the treatment plans, radiological findings and clinical courses of 86 patients suffering AVM associated with aneurysm.

RESULTS

Ninety-five aneurysms in 86 patients with AVMs were enrolled in this study. Hemorrhage was the most frequent presenting symptom (69 patients, 80.2%). Bleeding was caused by an AVM nidus in 44 cases, aneurysm rupture in 20 and an undetermined origin in 5. Four patients were treated for associated aneurysm with coils followed by AVM embolization and 82 patients were treated with NBCA or Onyx embolization. There were total of 3 complications (3.5%) clinically significant complications in this series. Excellent or good outcomes (Glasgow Outcome Scale ≥ 4) were observed in 63 (73.3%) patients at discharge. Neurological deficits (Glasgow Outcome Scale 1-4) were 16.6% at discharge.

CONCLUSION

Endovascular treatment can be adequately used for cerebral aneurysms associated with AVMs as an adjunct to microsurgery and radiosurgery.

Ruptured intrameatal aneurysm of the anterior inferior cerebellar artery accompanying an arteriovenous malformation: a case report

The distal anterior inferior cerebellar artery (AICA) aneurysms located inside the internal auditory canal are rare. The association of the distal AICA aneurysms and an arteriovenous malformation (AVM) on the same arterial trunk is exceptional. Eight reports of a total of ten cases have been published and all of the reported aneurysms were located in the meatal or postmeatal segment of the AICA. Herein, we report a case of ruptured aneurysm in the intrameatal portion of the AICA accompanying an AVM fed by the same artery. A 55-year-old man suffering from subarachnoid hemorrhage due to a ruptured intrameatal aneurysm with a small AVM underwent surgical trapping of the meatal loop, resulting in uneventful recovery. Follow-up angiography demonstrated neither aneurysm nor residual AVM nidus. We propose that trapping of the meatal loop could be a safe and feasible alternative to unroofing followed by neck clipping in selected patients with an intrameatal aneurysm of the AICA. We also review here the relevant literature.

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

BACKGROUND

To evaluate the characteristics of brain arteriovenous malformations (AVMs) with coexisting flow-related and Willis circle aneurysms.

METHODS

The 302 consecutive retrospectively reviewed patients from the Beijing Tiantan Hospital were analyzed in this study. The presence of cerebral aneurysms was confirmed by pretreatment selective and superselective angiography. Univariate and multivariate analyses were performed for patient age, sex, history of rupture, associated aneurysms, AVM size, and deep and superficial venous drainage.

RESULTS

Of the 302 patients, 41 (13.6%) had AVMs associated with intranidal aneurysms, and 33 (10.9%) had AVMs associated with extranidal aneurysms. Of the 33 patients, 24 (72.7%) had a flow-related and 9 (27.3%) had a Willis circle aneurysm. Flow-related and Willis circle aneurysms correlated positively with intracranial hemorrhage (P = 0.003), patient age (P = 0.003), and infratentorial AVMs (P = 0.040) in multiple univariate analysis.

CONCLUSIONS

Flow-related and Willis circle aneurysms coexisting with cerebral AVMs frequently are associated with initial hemorrhage presentation, patient age, and infratentorial AVM location.

Characteristics of arteriovenous malformations associated with cerebral aneurysms

OBJECTIVE

To analyze the characteristics of brain arteriovenous malformations (AVMs) associated with cerebral aneurysms.

METHODS

A total of 302 consecutive, retrospectively reviewed patients from the Beijing Tiantan Hospital were analyzed in this study. The presence of cerebral aneurysm was confirmed by pretherapeutic selective and superselective angiography. Clinical presentation was categorized as intracranial hemorrhage or nonhemorrhagic presentation. Univariate and multivariate statistical models were applied to test the effect of age, sex, AVM size and location, and venous drainage pattern.

RESULTS

Of the 302 patients, 74 (24.5%) had AVMs associated with cerebral aneurysms. AVMs coexisting with aneurysms were significantly associated with hemorrhage at initial presentation (2.27; 95% confidence interval 1.31-3.95; P = 0.003). Infratentorial AVM location was significantly associated with AVMs coexisting with aneurysms (2.31; 95% confidence interval 1.02-5.24; P = 0.040). Deep or superficial venous drainage, female sex, or AVM size were not significantly associated with AVMs coexisting with aneurysms. The regression model showed significant effect was found for initial presentation with hemorrhage (P = 0.003), age (P = 0.003), and infratentorial AVM location (P = 0.040).

CONCLUSIONS

Our findings suggest that AVMs associated with cerebral aneurysms are frequently associated with initial hemorrhage presentation and infratentorial AVM location.

Management of anterior inferior cerebellar artery aneurysms: endovascular treatment and clinical outcome

BACKGROUND AND PURPOSE

AICA aneurysms are rare and a challenge to treat surgically. We present our experience of the angiographic results and the clinical outcomes for 9 AICA aneurysms treated by EVT.

MATERIALS AND METHODS

Between 1997 and 2009, EVT was attempted for 9 AICA aneurysms. Six patients presented with SAH, and 3 aneurysms were found incidentally. The location of the aneurysms was the proximal AICA in 7 and the distal AICA in 2. Five aneurysms originated from an AICA-PICA variant. Clinical outcomes and procedural complications were evaluated, and angiography was performed 6, 12, and 24 months after embolization to confirm recanalization of the coiled aneurysm.

RESULTS

EVT was technically successful in 7 patients (78%). Surgical trapping was performed in 1 patient after failure of EVT, and another aneurysm occluded spontaneously, along with the parent artery during EVT. In 7 patients, the AICAs had good patency on postoperative angiography. Stent-assisted coiling was performed in 3 patients. Follow-up angiographies were performed in 7 patients and showed no evidence of recanalization or progressive occlusion with further thrombosis except in 1 patient. There was no evidence of aneurysm rupture during the follow-up period, and 8 patients were able to perform all usual activities (mRS score, 0-1).

CONCLUSIONS

EVT may provide a feasible and safe option as an alternative, though a microsurgical option is initially considered for the management of AICA aneurysms. Further follow-up and more experience are also necessary.

A case of ruptured peripheral aneurysm of the anterior inferior cerebellar artery associated with an arteriovenous malformation : a less invasive image-guided transcortical approach

A 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system. The association of a peripheral AICA aneurysm and a cerebellar AVM by the same artery is unique. The reported cases of conventional surgery for this disease complex are not common and their results are variable. Less invasive surgery using image-guided neuronavigation system would be helpful and feasible for a peripheral aneurysm combining an AVM of the posterior fossa in selective cases.

Parent artery occlusion for peripheral anterior inferior cerebellar artery aneurysm. A case report and review of the literature

Most cases of aneurysms associated with the distal portion of the anterior inferior cerebellar artery resulted in a hearing disturbance from the surgical procedure, although aneurysms far from the auditory artery had no deficit from trapping. We describe a patient with an aneurysm at the distal segment of the anterior inferior cerebellar artery (AICA) treated endovascularly by parent artery occlusion.