Intraspinal canal platform system for coil embolization of anterior spinal artery aneurysm associated with spinal cord arteriovenous malformation: a case report and literature review.

BACKGROUND: The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature. CASE PRESENTATION: A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications. CONCLUSIONS: Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

Management of spinal aneurysms associated with arteriovenous malformations: systematic literature review and illustrative case.

PURPOSE: Spinal aneurysms are rare vascular malformations, commonly associated with spinal AVMs. AVM-associated spinal aneurysms are burdened by significant morbidity. The purpose of our study is to evaluate the best treatment strategy for these uncommon vascular lesions and to report an illustrative case. METHODS: We reviewed clinical and radiological data of a patient surgically treated at our institution for a spinal AVM with an associated prenidal aneurysm. According to PRISMA guidelines, a systematic literature review has been performed in order to discuss the best management AVM-associated prenidal aneurysms. RESULTS: In the reported case, the aneurysm showed spontaneous regression at follow-up after surgical removal of the AVM. Only 6 articles reported management of spinal prenidal AVM-associated aneurysms. Basing on our experience and data from literature, surgical treatment of the aneurysm may be indicated along with the resection of the AVM if the aneurysm is close to the nidus. Conversely, if the aneurysm is far away from the nidus or in an unfavorable position, resection of the nidus only may lead to aneurysm regression as in the reported case. CONCLUSIONS: The treatment strategy for AVM-associated spinal aneurysms should be tailored on the single patient. In presence of large aneurysms that cause mass-effect symptoms, when rupture of the aneurysm is suspected or when treatment of the AVM is not proposable, direct treatment of the aneurysm should be considered. Otherwise, when complete resection of the nidus is performed, the eventually associated unruptured aneurysms located in challenging positions can be safely managed conservatively.

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.

Parent artery occlusion for flow-related aneurysms at the proximal segment of the main feeding arteries of cerebellar arteriovenous malformations.

BACKGROUND: Flow-related aneurysms (FRAs) associated with cerebellar arteriovenous malformations (AVMs) are complicated, and their management is difficult. We performed a retrospective study to explore the efficacy and outcome of parent artery occlusion (PAO) for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs. MATERIALS AND METHODS: A retrospective study was performed for patients admitted for a cerebellar AVM between January 2015 and December 2019. Patients were included if (a) they presented with a ruptured or symptomatic FRA at the proximal segment of the main feeding arteries of the cerebellar AVM, (b) the cerebellar AVM did not bleed before admission, (c) the FRA was secured via PAO of the parent feeding artery, and (d) the cerebellar AVM was not intentionally managed or embolized through other feeding arteries during hospitalization. RESULTS: Eight patients aged between 27 and 72 (48.6 ± 14.3) years were identified. Eight ruptured and symptomatic FRAs at the proximal segment of the main feeding arteries of the cerebellar AVMs underwent PAO with coils or Onyx while preserving the arteries distal to the aneurysms. All the patients achieved a favorable recovery after treatment in a follow-up ranged from 8 to 48 months. One patient experienced FRA recurrence and underwent a second PAO. CONCLUSIONS: PAO for FRAs at the proximal segment of the main feeding arteries of cerebellar AVMs is a feasible option. This method is effective in preventing re-rupture of the FRAs and relieving the symptoms in the short term, allowing sufficient time for the patients to receive subsequent treatment.

A single-institution study of predisposing factors of patients with BAVMs to flow-related aneurysm.

BACKGROUND AND PURPOSE: The goal of this study was to assess the potential risk factors leading to flow-related aneurysm (FA) formation in patients with brain arteriovenous malformations (BAVMs) in Taiwanese. METHODS: We recruited 890 patients with BAVMs: 72 had FA(s) and 818 did not. Several factors were assessed including patient's age, gender, BAVM volume and location, and Spetzler-Martin grade. RESULTS: The 890 patients with BAVM had a mean age of 30 years (range: 2-84), mean BAVM volume of 10.6 mL (range: 0.13-91.4). BAVMs were ruptured in 42% of patients. Compared to BAVM patients without FAs, the 72 patients with FAs had older age (mean 41 yrs vs 31 yrs, p < 0.001); larger average BAVM volume (39.6 mL vs 16.1 mL, p < 0.001). No statistical significance in Spetzler-Martin grades (χ2 value = 8.687 and p = 0.122) was found in terms of formation of FA. FA demonstrated similar gender distribution and BAVM location distribution (the χ2-value was 0.242 and 0.812, respectively). CONCLUSION: Patients with older age and large BAVM volume are more prone to FA. Gender, BAVM location, and BAVM grade are not statistically significant predisposing factors for FA.

Management of intracranial aneurysms associated with arteriovenous malformations.

Intracranial or brain arteriovenous malformations (BAVMs) are some of the most interesting and challenging lesions treated by the cerebrovascular neurosurgeon. It is generally believed that the combination of BAVMs and intracranial aneurysms (IAs) is associated with higher hemorrhage rates at presentation and higher rehemorrhage rates and thus with a more aggressive course and natural history. There is wide variation in the literature on the prevalence of BAVM-associated aneurysms (range 2.7%-58%), with 10%-20% being most often cited in the largest case series. The risk of intracranial hemorrhage in patients with unruptured BAVMs and coexisting IAs has been reported to be 7% annually, compared with 2%-4% annually for those with BAVM alone. Several different classification systems have been applied in an attempt to better understand the natural history of this combination of lesions and implications for treatment. Independent of the classification used, it is clear that a few subtypes of aneurysms have a direct hemodynamic correlation with the BAVM itself. This is exemplified by the fact that the presence of a distal flow-related or an intranidal aneurysm appears to be associated with an increased hemorrhage risk, when compared with an aneurysm located on a vessel with no direct supply to the BAVM nidus. Debate still exists regarding the etiology of the association between those two vascular lesions, the subsequent implications for patients' risk of hemorrhagic stroke, and finally the determination of which patients warrant treatment and when. The ultimate goals of the treatment of a BAVM associated with an IA are to prevent hemorrhage, avoid stepwise neurological deterioration, and eliminate the mortality risk associated with recurrent hemorrhagic events. The treatment is only justifiable if the risks associated with an intervention are lower than or equivalent to the long-term risks of disability or mortality caused by the lesion itself. When faced with this difficult decision, a few questions need to be answered by the treating neu-rosurgeon: What is the mode of presentation? What is the symptomatic lesion? Which one of the lesions bled? What is the relationship between the BAVM and IA? Is it possible to safely treat both BAVM and IA? The objective of this review is to discuss the demographics, natural history, classification, and strategies for management of BAVMs associated with IAs.

Long-term hemodynamic changes in cerebral proliferative angiopathy presenting with intracranial hemorrhage: illustrative case.

BACKGROUND: Cerebral proliferative angiopathy (CPA) is a rare vascular proliferative disease; however, long-term follow-up reports are scarce. The authors report a rare case and document a patient's medical history over 20 years. OBSERVATIONS: A 5-year-old girl developed left frontal lobe hemorrhage, presenting with headache. At 8 years of age, angiography showed diffuse capillary ectasia without an arteriovenous shunt. Single-photon emission computed tomography (SPECT) showed normal cerebral blood flow (CBF). She had normal growth without systemic disease. At 25 years of age, an intraventricular hemorrhage occurred, presenting with sudden headache. Angiography revealed vascular lesion enlargement, increased feeding arteries, dural supply to the nidus and peri-nidal lesion, and flow-related aneurysm. SPECT showed remarkable decreases in CBF in the nidus and peri-nidal lesion. Cerebral proliferative angiopathy (CPA) was diagnosed, and the aneurysm arising at the lateral posterior choroidal artery caused the hemorrhage. Coil embolization of the aneurysm was performed with a flow-guide catheter and extremely soft platinum coils. New aneurysms were not noted 1.5 years after the procedure. LESSONS: This is the first report to demonstrate hemodynamic changes in CPA on angiography and SPECT over 17 years. The development of endovascular devices has enabled the embolization of ruptured aneurysms at the peripheral cerebral artery.

Disappearance of a Ruptured Feeding Artery Fusiform Aneurysm After the Resection of a Large Subependymoma: A Case Report.

Aneurysm formation on the tumor-feeding artery is rare, and its treatment strategies are not yet settled. We herein report the case of a 49-year-old female with a large subependymoma in the left lateral ventricle presenting remote intracerebral hemorrhage at the left posterior cingulate gyrus. Digital subtraction angiography (DSA) revealed the presence of a 5.5 mm fusiform tumor-feeding artery aneurysm on the left parieto-occipital branch of the posterior cerebral artery, considered to be the source of the hemorrhage. Three months after total tumor resection, the aneurysm subsequently disappeared on the follow-up angiography. Subependymomas are generally known as tumors with low vascularity and seldom present with symptoms such as intracerebral hemorrhage. From the subsequent disappearance of the aneurysm after the complete tumor resection, the pathophysiological cause of the aneurysm formation is assumed to be flow-related hemodynamic vessel wall stress of the feeding artery. Tumor resection alone may be a favorable first treatment strategy to avoid unnecessary brain damage since subsequent disappearance of the aneurysm can be expected. The coexistence of feeding artery aneurysms should be kept in mind, especially in cases with remote hemorrhage.

Role of Endovascular Approach as Diagnostic Technique and First-Line Therapy for the Patients with Micro-Arteriovenous Malformations: A Case Report and Literature Review.

Objective: We describe a rare case report of micro-arteriovenous malformation (micro-AVM) treated by the endovascular approach in addition with literature review. Case Presentation: A 12-year-old boy presenting with a spontaneous intracerebral hematoma in the left occipital lobe underwent conventional diagnostic workups. The results of initial catheter angiography were considered to be equivocal as the AVM. Superselective angiography (SA) demonstrated a micro or small AVM (single feeder and single drainer type) with an aneurysmal dilatation. Immediate transarterial embolization (TAE) might fail to occlude the whole of nidus area completely, and subsequently, we switched to the surgical exploration of AVM lesion. Intraoperative findings demonstrated that the whole of AVM lesion had already been occluded completely, indicating the complete occlusion by TAE only. Pathological findings of the surgical specimen showed an aneurysmal dilatation was a venous aneurysm with vulnerable vascular wall structure, which was certainly the source of bleeding. Based on the above results, the retrospective revaluation of superselective angiogram permitted us to understand that the nidus of AVM was micro nidus type and TAE had resulted in the complete nidus occlusion. Conclusion: SA is the most useful diagnostic modality to clarify the angioarchitecture of micro-AVM and AVM-related aneurysms. If SA is successfully performed and relatively safe TAE is expected to be possible, the subsequent attempt to do curative embolization as a first-line treatment may be worthy of consideration. However, the surgical procedure should be fully reserved for the possible incomplete obliteration and hemorrhagic complications.

Multiple flow-related intracranial aneurysms in the setting of contralateral carotid occlusion: Coincidence or association?

The prevalence of intracranial aneurysms (IAs) is higher in patients with internal carotid artery (ICA) stenosis, likely due to alterations in intracranial hemodynamics. Severe stenosis or occlusion of one ICA may result in increased demand and altered hemodynamics in the contralateral ICA, thus increasing the risk of contralateral IA formation. In this article, we discuss a relevant case and a comprehensive literature review as it pertains to the association of ICA stenosis and IA. Our patient was a 50-year-old female with a chronic asymptomatic right ICA occlusion who presented with diffuse subarachnoid hemorrhage. Emergent angiography revealed left-sided A1-A2 junction, paraclinoid, left middle cerebral artery (MCA) bifurcation, and left anterior temporal artery aneurysms. Brisk filling of the right anterior circulation through the anterior communicating artery was also identified, signifying increased demand on the left ICA circulation. Complete obliteration of all aneurysms was achieved with coil embolization and clipping. For our literature review, we searched the PubMed and EMBASE databases for case reports and case series, as well as references in previously published review articles that described patients with concurrent aneurysms and ICA stenosis. We selected articles that provided adequate information about the case presentations to compare aneurysm and patient characteristics. Our review revealed a higher number of patients with multiple aneurysms contralateral (25%) to rather than ipsilateral to (6%), the ICA stenosis. We discuss the pathogenesis and management of multiple flow-related IA in the context of the existing literature related to concurrent ICA stenosis and IA.

Endovascular treatment for the flow-related aneurysm originating from an anterior inferior cerebellar artery supplying the cerebellar arteriovenous malformation.

BACKGROUND: When a flow-related aneurysm originates from an anterior inferior cerebellar artery (AICA) supplying the cerebellar arteriovenous malformation (AVM), the management becomes very complicated. Endovascular treatment (EVT) was an option, but no consensus has been achieved.Methods and materials: A retrospective investigation was performed for patients with flow-related aneurysm originating from an AICA supplying the cerebellar AVM. RESULTS: Ten patients, harboring 13 aneurysms, were identified. Of the 5 a1 aneurysms, 2 underwent stent assisted coiling, 2 underwent parent artery occlusion (PAO), and 1 was intact. Of the 8 a2 aneurysms, 3 underwent coiling with preservation of the AICA, 3 underwent PAO with Onyx, 1 underwent PAO with coils, and 1 was intact. Seven patients underwent partial embolization of the cerebellar AVM, 3 were intact. One patient died 6 hours postoperatively for cerebellar AVM rebleeding. During a follow-up from 6 months to 6 years, 9 patients had favorable recovery. CONCLUSION: For the flow-related aneurysm originating from an AICA supplying the cerebellar AVM, the EVT depends on the specific circumstances. When the aneurysm is located at the a1 segment, coiling of the aneurysm with preservation of the parent AICA should be performed. PAO is the last resort. When the a2 aneurysm is proximal to the internal auditory artery, coiling of the aneurysm with preservation of the AICA is preferred. When the aneurysm is distal to the internal auditory artery, PAO can be safely performed.

Anterior Spinal Artery Steal Syndrome Complicated by Ruptured Flow-Related Aneurysm of the Anterior Radiculomedullary Artery.

BACKGROUND: Anterior spinal artery steal syndrome, radiculomedullary artery aneurysms, and pulmonary arteriovenous malformations with a systemic origin are each, considered individually, exceptional conditions. CASE DESCRIPTION: We describe the coexistence of all these conditions and their pathophysiologic relationship by presenting the case of a woman who referred to the emergency department for loss of consciousness and a history of 2 days of medullary symptoms and a subsequent acute respiratory failure. Detailed imaging revealed a subarachnoid hemorrhage due to the rupture of a spinal aneurysm located in a C8 radiculomedullary artery that had its flow reversed toward the deep cervical artery from which a systemic to pulmonary arteriovenous malformation originated. CONCLUSIONS: Eventually, the lesion was treated with the exclusion of the left C8 spinal segmental branch and embolization of the arteriovenous malformation.

Pipeline Flex Embolization of Flow-Related Aneurysms Associated with Arteriovenous Malformations: A Case Report.

BACKGROUND: An estimated 0.1% of the population harbors brain arteriovenous malformations (AVMs). Diagnosis and workup of AVMs include thorough evaluation for characterization of AVM angioarchitecture and careful assessment for concomitant aneurysms. The presence of coexisting aneurysms is associated with an increased risk of intracranial hemorrhage, with a published risk of 7% per year compared to patients with AVMs alone with a risk of 3%. Comprehensive AVM management requires recognition of concomitant aneurysms and prioritizes treatment strategies to mitigate the aggregate risk of intracranial hemorrhage associated with AVM rupture in patients with coexisting aneurysms. Endovascular treatment of these flow-related aneurysms can offer a cure, while avoiding open surgery. Successful flow-diverting embolization techniques, efficacy, and outcomes have been previously described for a variety of aneurysm types and locations. However, use of a flow diverter has not been previously described for the treatment of high-flow aneurysms on AVM-feeding vessels. CASE PRESENTATION: We report 2 cases of large AVMs within eloquent cortex associated with flow-related aneurysms in patients presenting initially with suspected intracerebral hemorrhage secondary to AVM rupture. DISCUSSION: No consensus currently exists to guide treatment of intracranial aneurysms associated with AVMs. Surgical management addressed AVM embolization initially, as the vasculopathology with the highest rupture risk. Subsequently, Pipeline embolization of the associated aneurysms with adequate antiplatelet treatment was performed before scheduled radiosurgery to decrease the risk of AVM rupture or rebleed. This represents a novel and promising use of the Pipeline Embolization Device. Additional cases and longer follow-up will be needed to further assess the efficacy of this technique.

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.

Disappearance of a Ruptured Distal Flow-Related Aneurysm after Arteriovenous Malformation Nidal Embolization.

Aneurysms associated with arteriovenous malformations (AVMs) are well represented in the literature. Their exact etiology is poorly understood, but likely global hemodynamic changes coupled with vascular wall pathology play into their formation. Flow-related and intranidal aneurysms, in particular, appear to have an increased risk for hemorrhagic presentation. Treatment strategies for these aneurysms are particularly challenging. We report the case of an AVM-associated aneurysm causing intraventricular hemorrhage that disappeared after embolization of unrelated, distal feeding pedicles to the nidus, at a site distant from the aneurysm. We also review the literature with regards to these so-called "disappearing aneurysms" in the context of AVMs and other vascular pathologies.

Fatal rupture of a brain arteriovenous malformation flow-related aneurysm during microcatheter removal: a rare complication.

Intracranial aneurysms are relatively frequently encountered in patients with brain arteriovenous malformations (BAVMs). They may be located on the circle of Willis, on arterial feeders, or even inside the nidus. Because BAVM-associated aneurysms represent a risk factor of bleeding, the question of the timing and modality of their management remains a matter of debate in unruptured BAVMs. The authors present a case of fatal periprocedural rupture of a flow-related aneurysm (FRA) during the removal of the microcatheter after injection of a liquid embolic agent. A 40-year-old man was treated at the authors' institution for the management of a Spetzler-Martin Grade III left unruptured frontal BAVM, revealed by seizures and a focal neurological deficit attributed to flow steal phenomenon. After a multidisciplinary meeting, endovascular treatment was considered to reduce the flow of the BAVM. A proximal FRA located on the feeding internal carotid artery (ICA) was purposely left untreated because it did not meet the criteria of the authors' institution for preventative treatment (i.e., small size [2.5 mm]). During embolization, at the time of microcatheter retrieval, and after glue injection, the aneurysm unexpectedly ruptured. The aneurysm's rupture was attributed to the stress (torsion/flexion) on the ICA caused by the microcatheter removal. Despite the attempts to manage the bleeding, the patient eventually died of the acute increase of intracranial pressure related to the massive subarachnoid hemorrhage. This case highlights a previously unreported mechanism of FRA rupture during BAVM embolization: the stress transmitted to the parent artery during the removal of the microcatheter.