Assessing the rate, natural history, and treatment trends of intracranial aneurysms in patients with intracranial dural arteriovenous fistulas: a Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) investigation

OBJECTIVE

There is a reported elevated risk of cerebral aneurysms in patients with intracranial dural arteriovenous fistulas (dAVFs). However, the natural history, rate of spontaneous regression, and ideal treatment regimen are not well characterized. In this study, the authors aimed to describe the characteristics of patients with dAVFs and intracranial aneurysms and propose a classification system.

METHODS

The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database from 12 centers was retrospectively reviewed. Analysis was performed to compare dAVF patients with (dAVF+ cohort) and without (dAVF-only cohort) concomitant aneurysm. Aneurysms were categorized based on location as a dAVF flow-related aneurysm (FRA) or a dAVF non-flow-related aneurysm (NFRA), with further classification as extra- or intradural. Patients with traumatic pseudoaneurysms or aneurysms with associated arteriovenous malformations were excluded from the analysis. Patient demographics, dAVF anatomical information, aneurysm information, and follow-up data were collected.

RESULTS

Of the 1077 patients, 1043 were eligible for inclusion, comprising 978 (93.8%) and 65 (6.2%) in the dAVF-only and dAVF+ cohorts, respectively. There were 96 aneurysms in the dAVF+ cohort; 10 patients (1%) harbored 12 FRAs, and 55 patients (5.3%) harbored 84 NFRAs. Dural AVF+ patients had higher rates of smoking (59.3% vs 35.2%, p < 0.001) and illicit drug use (5.8% vs 1.5%, p = 0.02). Sixteen dAVF+ patients (24.6%) presented with aneurysm rupture, which represented 16.7% of the total aneurysms. One patient (1.5%) had aneurysm rupture during follow-up. Patients with dAVF+ were more likely to have a dAVF located in nonconventional locations, less likely to have arterial supply to the dAVF from external carotid artery branches, and more likely to have supply from pial branches. Rates of cortical venous drainage and Borden type distributions were comparable between cohorts. A minority (12.5%) of aneurysms were FRAs. The majority of the aneurysms underwent treatment via either endovascular (36.5%) or microsurgical (15.6%) technique. A small proportion of aneurysms managed conservatively either with or without dAVF treatment spontaneously regressed (6.2%).

CONCLUSIONS

Patients with dAVF have a similar risk of harboring a concomitant intracranial aneurysm unrelated to the dAVF (5.3%) compared with the general population (approximately 2%-5%) and a rare risk (0.9%) of harboring an FRA. Only 50% of FRAs are intradural. Dural AVF+ patients have differences in dAVF angioarchitecture. A subset of dAVF+ patients harbor FRAs that may regress after dAVF treatment.

Clinical importance of the posterior meningeal artery: a review of the literature

The posterior meningeal artery, which arises from the vertebral artery, is a critical artery in neurological lesions. However, a comprehensive review of the importance of the posterior meningeal artery is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the posterior meningeal artery to increase our understanding of its role in vascular lesions. The posterior meningeal artery provides the main blood supply to the paramedial and medial portions of the dura covering the cerebellar convexity. The posterior meningeal artery is often involved in dural arteriovenous fistulas occurring near the posterior fossa, and the posterior meningeal artery can be the path for transarterial embolisation or a path through which to monitor the degree of dural arteriovenous fistula embolisation. In posterior circulation ischaemia and moyamoya disease, the posterior meningeal artery can form transdural anastomoses with pial arteries at the surface of the brain, and these can help prevent ischemia. The posterior meningeal artery can also develop aneurysms, most of which are traumatic pseudoaneurysms; patients should therefore be treated in a timely manner or followed up carefully in cases of rebleeding. In addition, during a craniotomy, the posterior meningeal artery should be protected intraoperatively to avoid damaging any transdural anastomosis that may be present. In addition, when the posterior meningeal artery is the main feeding artery of an intracranial tumour, that artery is a satisfactory path for preoperative embolisation. Briefly, the posterior meningeal artery is a very important artery in neurosurgery.

Arterial aneurysms associated with intracranial dural arteriovenous fistulas: epidemiology, natural history, and management. A systematic review

Arterial aneurysms are uncommon among patients with dural arteriovenous fistulae (DAVFs), and there is limited information available to guide treatment decisions in such cases. We performed a systematic review of the literature, including a case of a DAVF associated with a flow-related intraorbital ophthalmic artery (OA) aneurysm that we have recently managed. The purpose of our study was to clarify epidemiology, natural history, and management of these lesions. A total of 43 published cases of DAVF associated aneurysms were found in 26 studies on the topic. Anterior cranial fossa was the most common location (40%), and ethmoidal branches were the most common arterial feeders (55%). In about 63% of cases, the aneurysm was located on artery unrelated to DAVF supply. Approximately 10% of intracranial DAVFs were associated with aneurysms located in the intraorbital OA. Overall, 70% of lesions were Borden type III, and 50% of patients presented with hemorrhage. In approximately 17% of cases, the source of bleeding was a feeding artery aneurysm. All of the reported intraorbital OA aneurysms associated with DAVFs remained stable during follow-up. DAVF associated aneurysms are fairly rare. Anterior cranial fossa location and direct cortical venous drainage are common among these lesions. The aneurysms are less likely to be located on feeding arteries, and hemorrhagic presentation related to flow-related aneurysm rupture is uncommon.

Rupture of an aneurysm of the superior cerebellar artery feeding a dural arteriovenous fistula

We experienced a very rare case of bleeding from an aneurysm of a branch of the superior cerebellar artery, which feeds a dural arteriovenous fistula (DAVF) of the posterior fossa. The aneurysm was not detected on initial angiography and 2 episodes of rebleeding resulted in deterioration of the patient's condition. Although rare, aneurysms of the pial feeding arteries should be considered as a cause of bleeding in cases of DAVF.

Aneurysm of the posterior meningeal artery embedded within a dorsal exophytic medullary hemangioblastoma: surgical management and review of literature

Hemangioblastomas are World Health Organization (WHO) Grade I neoplasms of the hindbrain and spinal cord, whose management can be complicated by preoperative hemorrhage. We report on a case of a young female in extremis with posterior fossa hemorrhage following rupture of a fusiform posterior meningeal artery aneurysm embedded within a medullary hemangioblastoma. We discuss management options, including operative staging and embolization, and review similar cases of hemangioblastoma associated with aneurysm.

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.

Cerebral dural arteriovenous fistulas and aneurysms

Object

The association of aneurysms and cerebral arteriovenous malformations is well established in the literature. Aside from a small number of case reports and small patient series, this association has not been well explored with cerebral dural arteriovenous fistulas (DAVFs). This study was designed to elucidate this relationship in the authors' own patient cohort with DAVFs.

Methods

Cerebral angiograms of 56 patients with 70 DAVFs were reviewed for the presence of cerebral aneurysms. Background patient demographics, mode of presentation, and DAVF and aneurysm angiographic characteristics were noted.

Results

Twelve patients (21%) had aneurysms in addition to their DAVF. Three patients had multiple aneurysms. Of a total of 15 aneurysms, 5 (33%) occurred on DAVF feeding arteries and 10 (67%) were in remote locations. These patients more commonly presented with hemorrhage (58% vs 20% for those without aneurysms). Aneurysms were associated with DAVFs in any location (feeding artery or remote), but flow-related feeding artery aneurysms were more likely to be associated with Borden Type III DAVFs.

Conclusions

Twenty-one percent of patients with cerebral DAVFs also had aneurysms in this patient cohort. It is thus prudent to perform 6-vessel digital subtraction angiography on patients with DAVFs to rule out potential feeding artery and remote aneurysms. This association may be explained by flow-related phenomena, the initial inciting event leading to DAVF formation, as well as a potential genetic component or predisposition to develop these lesions.