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

Ruptured proximal pontine artery aneurysm and association with cerebellopontine angle cistern arterial venous malformation fed by the same artery: A surgical challenge

Background

The coexistence of hyper-inflow aneurysms and cerebellopontine angle cistern (CPAc) arterial venous malformations (AVMs) have been rarely reported and most commonly associated with high risk of bleeding.

Case Descriptions

We present two cases of CPAc AVMs admitted for acute subarachnoid hemorrhage from rupture of a parent right pontine artery aneurysm. Admission history, neurology at presentation, pre/post-operative imaging, approach selection, and results are thoroughly reviewed and presented. The acute origin angle of the vessel from the basilar artery made both malformations unsuitable for endovascular treatment. The surgical strategy was differently tailored in the two patients, respectively, using a Le Fort I/transclival and a Kawase approach. The aneurysm was clipped in the first case, and the AVM was excised in the second one, as required by the anatomical context. Aneurysm exclusion and AVM size reduction were obtained in the first case, while complete AVM removal and later aneurysm disappearance were obtained in the second one. A high-flow cerebrospinal fluid leak in the first case was successfully treated by an endoscopic approach. Both patients experienced a satisfactory neurological outcome in the follow-up.

Conclusion

Pontine artery aneurysms, especially when associated with CPAc AVMs, represent a surgical challenge, due to their rarity and anatomical peculiarity, which typically requires complex operative approaches. Multimodal preoperative imaging, appropriate timing, and accurate target selection, together with versatile strategies, are the keys to a successful treatment.

Evaluation of theTherapeutic Effect of the Hybrid Operation on Patients with Aneurysms Associated with Cerebral Arteriovenous Malformations with different Redekop Classifications

BACKGROUND

Intracranial aneurysms associated with cerebral arteriovenous malformations (AVMs) are a rare condition in the clinic, and treatment is very difficult due to their particular anatomical features. We present our experience in the treatment of intracranial aneurysms with AVMs and evaluate the effectiveness and safety of endovascular treatment combined with microsurgical resection (the hybrid operation).

METHODS

This was a single-center retrospective study in our neurosurgical department from January 2015 to January 2021. We collected clinical data from 48 patients with intracranial aneurysms associated with AVMs and categorized them according to Redekop classifications according to the results of cerebral imaging examination to compare the therapeutic effects of endovascular embolization and the hybrid operation.

RESULTS

Compared to nonaneurysmal AVMs, intracranial aneurysms with AVMs more often presented with intracranial hemorrhage (P<0.05). Massive hematoma and severe neurological impairment were more often found in patients with intracranial aneurysms with AVMs (P<0.05). For flow-related aneurysms, the hybrid surgery had a higher one-stage cure rate than endovascular embolization alone (P<0.05). Both treatment methods had similar effects on intranidal aneurysms (P>0.05). There were no significant differences in prognostic indicators between the two treatments. However, the recurrence rate of AVMs with proximal flow-related aneurysms was lower in patients who underwent the hybrid operation (P<0.05).

CONCLUSION

The hybrid operation was safe and effective for patients with intracranial aneurysms associated with AVMs. For flow-related aneurysms, the one-stage cure rate was higher and the recurrence rate was lower with the hybrid operation than with endovascular embolization alone.

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.

Ruptured distal AICA pseudoaneurysm presenting years after vestibular schwannoma resection and radiation

Distal anterior inferior cerebellar artery (AICA) pseudoaneurysms are very rare lesions. Although cases have been previously reported, only a few have been reported as a result of vestibular schwannoma (VS) radiation, none have been reported as a result of VS resection, and only one has been reported as treated with parent vessel occlusion (PVO) with n-butyl cyanoacrylate (nBCA). We report a case of a 65-year-old man with a history of right-sided VS surgery and radiation who presented years later with a ruptured pseudoaneurysm of the distal right AICA and was treated with endovascular PVO using nBCA. The aneurysm was completely obliterated and the patient had no worsening of symptoms or neurological exam. The case illustrates a very rare complication of VS surgery and radiation as well as an effective treatment for distal AICA aneurysms.

Ruptured distal AICA pseudoaneurysm presenting years after vestibular schwannoma resection and radiation

Distal anterior inferior cerebellar artery (AICA) pseudoaneurysms are very rare lesions. Although cases have been previously reported, only a few have been reported as a result of vestibular schwannoma (VS) radiation, none have been reported as a result of VS resection, and only one has been reported as treated with parent vessel occlusion (PVO) with n-butyl cyanoacrylate (nBCA). We report a case of a 65-year-old man with a history of right-sided VS surgery and radiation who presented years later with a ruptured pseudoaneurysm of the distal right AICA and was treated with endovascular PVO using nBCA. The aneurysm was completely obliterated and the patient had no worsening of symptoms or neurological exam. The case illustrates a very rare complication of VS surgery and radiation as well as an effective treatment for distal AICA aneurysms.

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.