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Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR): rationale, design, and initial characterization of patient cohort

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Abstract

OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are rare lesions, hampering efforts to understand them and improve their care. To address this challenge, investigators with an established record of dAVF investigation formed an international, multicenter consortium aimed at better elucidating dAVF pathophysiology, imaging characteristics, natural history, and patient outcomes. This report describes the design of the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) and includes characterization of the 1077-patient cohort. METHODS Potential collaborators with established interest in the field were identified via systematic review of the literature. To ensure uniformity of data collection, a quality control process was instituted. Data were retrospectively obtained. RESULTS CONDOR comprises 14 centers in the United States, the United Kingdom, the Netherlands, and Japan that have pooled their data from 1077 dAVF patients seen between 1990 and 2017. The cohort includes 359 patients (33%) with Borden type I dAVFs, 175 (16%) with Borden type II fistulas, and 529 (49%) with Borden type III fistulas. Overall, 852 patients (79%) presented with fistula-related symptoms: 427 (40%) presented with nonaggressive symptoms such as tinnitus or orbital phenomena, 258 (24%) presented with intracranial hemorrhage, and 167 (16%) presented with nonhemorrhagic neurological deficits. A smaller proportion (224 patients, 21%), whose dAVFs were discovered incidentally, were asymptomatic. Many patients (85%, 911/1077) underwent treatment via endovascular embolization (55%, 587/1077), surgery (10%, 103/1077), radiosurgery (3%, 36/1077), or multimodal therapy (17%, 184/1077). The overall angiographic cure rate was 83% (758/911 treated), and treatment-related permanent neurological morbidity was 2% (27/1467 total procedures). The median time from diagnosis to follow-up was 380 days (IQR 120–1038.5 days). CONCLUSIONS With more than 1000 patients, the CONDOR registry represents the largest registry of cranial dAVF patient data in the world. These unique, well-annotated data will enable multiple future analyses to be performed to better understand dAVFs and their management.

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... The formation and methodology of the CONDOR database has been described in detail elsewhere. 12 All centers had institutional or ethics committee approval with waiver of written informed consent. Data of patients with dAVF and CVD were extracted. ...
Article
BACKGROUND Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2–14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3–5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7–12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4–37.7; P , 0.026). CONCLUSIONS The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.
... The infrastructure for CONDOR is described elsewhere in detail. 39 Briefly, collaborating institutions obtained individual institutional review board approval to conduct a retrospective analysis of all dAVFs treated at each institution. Details were collected from the clinical record and imaging databases, de-identified, and shared via a third-party host institution. ...
Article
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.
Chapter
Stereotaxic radiosurgery (SRS) is an important alternative, additive or salvage intervention for the treatment of dural arteriovenous fistulas (dAVF). Treatment with SRS can offer favorable rates of dAVF obliteration and offers a solution to dAVF not amenable or refractory to surgical or endovascular treatment. It is important to identify the factors associated with favorable outcomes following SRS. Recent studies suggest that anatomic location, angiographic and clinical criteria can affect the outcome of SRS. Established grading scales based on angiographic criteria are primarily focused on hemorrhage risk stratification and provide guidance regarding management but do not adequately predict effectiveness of SRS. The primary goal of this chapter is to outline the factors that predict dAVF obliteration as described in recent studies. We also describe a practical grading system by Nasser et al. that incorporates angiographic, anatomic and clinical parameters to specifically predict dAVF outcomes following SRS. Our goal is to help clinicians predict SRS outcomes on an individual basis and as such aid the decision-making process.KeywordsDural arteriovenous fistulaStereotaxic radiosurgeryGrading scalesPredictors
Article
Background Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs. Methods The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990–2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed. Results 60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs. Conclusion Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.
Chapter
Moyamoya Angiopathy (MMA) is an idiopathic, progressive intracranial occlusive vasculopathy leading to formation of abnormal vascular network of collaterals. Dural arteriovenous fistula (DAVF) has been rarely reported to co-exist with MMA. A paucity of literature has limited the elucidation of the pathophysiological association between the two conditions. It may be hypothesized that a chronic cerebral ischemic state in MMA and subsequent angiogenesis leading to the formation of collaterals might lead to the formation of DAVF. At present, there are no definite guidelines for treatment of DAVF in MMA. However, it may be reasonable to practice conservative management with close follow-up in case of asymptomatic DAVF or those without cerebral venous drainage, while high grade DAVF may be subjected to endovascular or open surgery to prevent future intracranial hemorrhage.
Article
Background and Purpose Dural arteriovenous fistulae can present with hemorrhage, but there remains a paucity of data regarding subsequent outcomes. We sought to use the CONDOR (Consortium for Dural Arteriovenous Fistula Outcomes Research), a multi-institutional registry, to characterize the morbidity and mortality of dural arteriovenous fistula–related hemorrhage. Methods A retrospective review of patients in CONDOR who presented with dural arteriovenous fistula–related hemorrhage was performed. Patient characteristics, clinical follow-up, and radiographic details were analyzed for associations with poor outcome (defined as modified Rankin Scale score ≥3). Results The CONDOR dataset yielded 262 patients with incident hemorrhage, with median follow-up of 1.4 years. Poor outcome was observed in 17.0% (95% CI, 12.3%–21.7%) at follow-up, including a 3.6% (95% CI, 1.3%–6.0%) mortality. Age and anticoagulant use were associated with poor outcome on multivariable analysis (odds ratio, 1.04, odds ratio, 5.1 respectively). Subtype of hemorrhage and venous shunting pattern of the lesion did not affect outcome significantly. Conclusions Within the CONDOR registry, dural arteriovenous fistula–related hemorrhage was associated with a relatively lower morbidity and mortality than published outcomes from other arterialized cerebrovascular lesions but still at clinically consequential rates.
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Article
Background: Anterior cranial fossa dural arterio-venous fistulas (DAVFs) represent 6% of all intracranial DAVFs; characteristically they show an aggressive behaviour with high risk of intracranial haemorrhage. Peculiar anatomical features, such as feeding by the ethmoidal arteries and the pattern of venous drainage (frequently with varices that mimic aneurysmal dilatation), can be evaluated in detail only by digital subtraction angiography (DSA), which represents the "gold standard" in the diagnosis of such cranial fistulas. Recent technological developments in endovascular management of this type of DAVF have partially reduced the morbidity risk related to this modality of treatment. Our purpose is to present our experience in the surgical management of 14 patients with anterior cranial fossa DAVFs, with attention paid to the possible role of preoperative embolisation in these cases and to the surgical technique. Method: Between 1999 and 2015, 14 patients with anterior cranial fossa DAVFs were submitted to surgery in two neurosurgical departments; the mean age was 63 years old; nine DAVFs caused intracranial haemorrhage (subarachnoid haemorrhage in three cases, intracerebral haemorrhage in six cases). Pre-operative embolisation was attempted in an early case and was successfully done in one recent case. In all patients, the surgical approach chosen was a pterional craniotomy with a low margin on the frontal bone in order to gain the exposure of the anterior cranial fossa and especially of the olphactory groove region; the resection of the falx at its insertion on the crista galli was needed in five cases in order to get access to the contralateral afferent vessels. Cauterisation of all the dural feeders on and around the lamina cribrosa was needed in all cases; venous dilatations were evident in eight patients (in seven out of nine patients with ruptured DAVF and in one out of five patients with unruptured DAVF) and were removed in all cases. One patient harboured an ophthalmic artery aneurysm, which was excluded by clipping. Results: One patient died 5 days after surgery due to the severity of the pre-operative haemorrhage. Postoperative DSA showed the disappearance of the DAVF and of the venous pseudo-aneurysms in all cases. Clinical outcome was favourable (without neurological deficits) in 11 patients; three patients presented an unfavourable clinical outcome, due to the severity of the initial haemorrhage. Conclusions: Surgical exclusion of the anterior cranial fossa DAVFs still represents the gold standard for such lesions, due to low post-operative morbidity and to complete protection against future rebleedings; endovascular techniques may help the surgeon in complex cases.
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Article
Ethmoidal dural arteriovenous fistulae are rare vascular malformations associated with a high risk of bleeding. We present a multicenter contemporary series of patients treated with microsurgical and endovascular techniques. Sixteen consecutive patients were evaluated and/or treated between 2008 and 2015 at four centers with large experience in the endovascular and surgical treatment of cerebrovascular diseases. We analyzed demographic and clinical data, risk factors for dural fistulas, treatment type, peri- and post-operative morbidity, clinical and radiological outcomes, rates of occlusion, and long-term neurological outcome. Sixteen patients (81 % men, mean age of 58 years) with ethmoidal dural fistulas were included in the analysis. Seven patients had suffered an intracranial hemorrhage; the remaining presenting with neurological signs and symptoms or the fistula was an incidental finding. Three patients were managed conservatively. Among patients who underwent intervention (n = 13), 46.1 % were treated with endovascular therapy and 53.9 % were treated surgically. Complete angiographic obliteration was achieved in 100 % immediately after treatment and at last follow-up evaluation. All patients experienced a favorable neurological recovery (mRS 0–2) at the last follow-up visit (12 months). Ethmoidal dural AVFs are found mostly in male patients. Nowadays, due to wider use of non-invasive imaging, AVFs are discovered with increasing frequency in patients with minimal or no symptoms. Traditionally, these fistulas were considered “surgical.” However, in the modern endovascular era, selected patients can be effectively and safely treated with embolization although surgical ligation continues to have an important role in their management.
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Introduction This study aims to review the diagnostic performance of computed tomography (CT) and magnetic resonance imaging (MRI) in symptomatic dural arteriovenous fistula (DAVF). Methods EMBASE, PubMed, and Cochrane Library were searched until April 2015 for studies which compared CT, MRI, or both with angiography for the detection of DAVF. The diagnostic performances of MRI and CT were indirectly compared using modality as a covariate in the analysis. Results Thirteen studies met our inclusion criteria. MRI had a sensitivity of 0.90 (95 % confidence interval (CI) = 0.83–0.94) and specificity of 0.94 (95 % CI = 0.90–0.96). CT had a sensitivity of 0.80 (95 % CI = 0.62–0.90) and specificity of 0.87 (95 % CI = 0.74–0.94). MRI showed better diagnostic performance than CT (p = 0.02). Contrast medium use and time-resolved MR angiography did not improve MRI diagnostic performance (p = 0.31 and 0.44, respectively). Conclusion Both CT and MRI had good diagnostic performance. MRI was better than CT on the detection of symptomatic intracranial dural arteriovenous fistula in the indirect comparison.
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Article
Background: The application of gamma knife radiosurgery (GKRS) alone has been expanded for dural arteriovenous fistulas (DAVFs). However, a standardized protocol delineating the appropriate circumstances for GKRS alone in cases of DAVF has yet to be determined. The purpose of this study was to report a single center's treatment algorithm for GKRS alone as a primary treatment for intracranial DAVFs and assess related clinical and radiological data. Method: Among 31 DAVF patients treated according to our institute's treatment algorithm between February 2009 and November 2014, 20 patients underwent GKRS alone. DAVF patients treated with GKRS alone fell in two main subgroups: DAVF patients without cortical venous reflux (CVR) but with symptoms (n = 8) and DAVF patients with CVR but without a high bleeding risk (defined as CVR with aggressive symptoms including hemorrhage or non-hemorrhagic neurological deficit, n = 11). One DAVF patient with a high bleeding risk had GKRS alone because of difficult endovascular access. Mean radiation volume was 4.8 cc (range, 0.7-14.2 cc), and mean maximal dose was 33.5 Gy (range, 28-38 Gy). Results: At mean follow-up of 29.1 months (range, 8-69 months), radiological findings demonstrated complete cures in 18 patients (90 %) and subtotal cures in 2 patients (10 %). One patient had a transient complication, but no neurologic sign. All symptomatic patients showed complete resolution. Conclusions: Our treatment algorithm showed GKRS alone may serve as a primary treatment for patients with DAVFs regardless of location and presence of CVR, unless there is a high bleeding risk. However, a multicenter, prospective study is necessary to generalize our treatment algorithm.
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Article
Object: The goal of this study was to evaluate the obliteration rate of intracranial dural arteriovenous fistulas (DAVFs) in patients treated with stereotactic radiosurgery (SRS), and to compare obliteration rates between cavernous sinus (CS) and noncavernous sinus (NCS) DAVFs, and between DAVFs with and without cortical venous drainage (CVD). Methods: A systematic literature review was performed using PubMed. The CS DAVFs and the NCS DAVFs were categorized using the Barrow and Borden classification systems, respectively. The DAVFs were also categorized by location and by the presence of CVD. Statistical analyses of pooled data were conducted to assess complete obliteration rates in CS and NCS DAVFs, and in DAVFs with and without CVD. Results: Nineteen studies were included, comprising 729 patients harboring 743 DAVFs treated with SRS. The mean obliteration rate was 63% (95% CI 52.4%-73.6%). Complete obliteration for CS and NCS DAVFs was achieved in 73% and 58% of patients, respectively. No significant difference in obliteration rates between CS and NCS DAVFs was found (OR 1.72, 95% CI 0.66-4.46; p=0.27). Complete obliteration in DAVFs with and without CVD was observed in 56% and 75% of patients, respectively. A significantly higher obliteration rate was observed in DAVFs without CVD compared with DAVFs with CVD (OR 2.37, 95% CI 1.07-5.28; p=0.03). Conclusions: Treatment with SRS offers favorable rates of DAVF obliteration with low complication rates. Patients harboring DAVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using SRS.
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Article
Background Dural arteriovenous fistulae can cause intracranial hemorrhage, but influences on this are unclear.Summary of reviewWe searched Ovid MEDLINE (from 1966), Embase (from 1980), and the Cochrane Library in September 2013 for studies of ≥50 adults with dural arteriovenous fistulae describing death or intracranial hemorrhage. Of 16 studies of retrospective associations between dural arteriovenous fistulae vascular anatomy and prior mode of presentation, fistula location in the cavernous sinus was consistently associated with nonhemorrhagic modes of presentation; in five studies involving 855 patients, fistulae with retrograde leptomeningeal (cortical) venous drainage were associated with prior presentation with intracranial hemorrhage (pooled odds ratio 23·2, 95% CI 13·8 to 39·0; I2 = 0%). Future intracranial hemorrhage during untreated clinical course was statistically significantly associated with the presence of venous varix in one study and with presentation with intracranial hemorrhage in patients with retrograde leptomeningeal venous drainage in another. In 19 observational studies of treatment of dural arteriovenous fistulae involving 2329 patients, the pooled risk of death was 1·2% (95% CI 0·6 to 1·8, I2 = 35%), that of nonfatal intracranial haemorrhage was 0·5% (95%CI 0·2 to 0·8, I2 = 9%), and that of nonfatal cerebral infarction was 0·7% (95% CI 0·3 to 1·4, I2 = 52%), for a combined risk of 2·5% (95% CI 1·4 to 3·9, I2 = 69%).Conclusions Retrograde leptomeningeal venous drainage seems strongly associated with intracranial hemorrhage at presentation of dural arteriovenous fistula, but its association with subsequent intracranial hemorrhage is less clear. Short-term complications of dural arteriovenous fistula treatment affect 2–3% of patients in published reports.
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Article
Rapidly increasing proptosis is rare in a newborn. The causes are diverse, and determining an exact etiology is difficult. We report a case of acute proptosis in a 26 day old infant due to dural fistula. To our knowledge, this is the youngest reported patient with a dural fistula. A multidisciplinary approach was essential to understanding the etiology of the proptosis in this child and providing adequate and successful treatment. © 2010 American Association for Pediatric Ophthalmology and Strabismus.
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A 59-year-old male presented with generalized seizure. The patient had not been aware of any traumatic head injuries or preceding infection, and had no contributory medical history. On admission, he was alert and well oriented, without neurological impairment or headache. He was afebrile and blood examination showed no abnormal findings. Computed tomography revealed an irregular intracerebral hematoma, 3 x 1.5 cm in diameter, in the left rectal gyrus. Cerebral angiography showed an arteriovenous fistula (AVF) in the anterior cranial fossa supplied only by the persistent primitive olfactory artery (PPOA) originating from the anterior cerebral artery, forming a shunt to an ascending cortical vein, and drained by the superior sagittal sinus. The patient underwent endovascular obliteration of the AVF via the transarterial route. Immediately after successful isolation, angiography showed that the bilateral anterior ethmoidal arteries supplied the AVF. The feeding branches from the left anterior ethmoidal artery were completely occluded via the ophthalmic artery, but introduction of the catheter into the right ophthalmic artery markedly decreased the stump pressure. Follow-up angiography performed at 3 and 8 weeks following embolization showed spontaneous resolution of the residual AVF without findings of recanalization or new abnormal channels. AVF arising in the anterior cranial fossa may be associated with an unusual pattern of the blood supply when including the PPOA.
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Article
Intracranial dural arteriovenous fistulas (AVFs) have been recognized as acquired lesions that can behave aggressively depending on the pattern of venous drainage. Based on the type of venous drainage, they can be classified as fistulas drained only by venous sinuses, those drained by venous sinuses with retrograde flow in arterialized leptomeningeal veins, and fistulas drained solely by arterialized leptomeningeal veins. Serious symptoms, including hemorrhage and focal deficit, are related to the presence of arterialized leptomeningeal veins. In this paper, the authors report a consecutive series treated between 1988 and 1993 of 20 cases of intracranial dural AVFs with "pure leptomeningeal drainage." All patients underwent surgical interruption of the leptomeningeal draining veins. Based on the arterial supply, nine patients were managed by direct surgery, whereas 11 patients were prepared for surgery by means of preoperative arterial embolization. Radioanatomical cure of the fistula and good neurological recovery were achieved in 18 cases. Complete obliteration of the fistula was documented angiographically in two cases, but fatal hemorrhage occurred, probably due to partial thrombosis of the venous drainage. Based on this experience, the authors believe that surgical interruption of the draining veins is the best treatment option for intracranial dural AVFs. However, surgical results may be affected by the extension of postoperative thrombosis, which in turn may be related to the degree of preoperative venous engorgement.
Article
OBJECTIVE The risk-to-benefit profile of treating an unruptured high-grade dural arteriovenous fistula (dAVF) is not clearly defined. The aim of this multicenter retrospective cohort study was to compare the outcomes of different interventions with observation for unruptured high-grade dAVFs. METHODS The authors retrospectively reviewed dAVF patients from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with unruptured high-grade (Borden type II or III) dAVFs were included and categorized into four groups (observation, embolization, surgery, and stereotactic radiosurgery [SRS]) based on the initial management. The primary outcome was defined as the modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were good outcome (mRS scores 0–2) at final follow-up, symptomatic improvement, all-cause mortality, and dAVF obliteration. The outcomes of each intervention group were compared against those of the observation group as a reference, with adjustment for differences in baseline characteristics. RESULTS The study included 415 dAVF patients, accounting for 29, 324, 43, and 19 in the observation, embolization, surgery, and SRS groups, respectively. The mean radiological and clinical follow-up durations were 21 and 25 months, respectively. Functional outcomes were similar for embolization, surgery, and SRS compared with observation. With observation as a reference, obliteration rates were higher after embolization (adjusted OR [aOR] 7.147, p = 0.010) and surgery (aOR 33.803, p < 0.001) and all-cause mortality was lower after embolization (imputed, aOR 0.171, p = 0.040). Hemorrhage rates per 1000 patient-years were 101 for observation versus 9, 22, and 0 for embolization (p = 0.022), surgery (p = 0.245), and SRS (p = 0.077), respectively. Nonhemorrhagic neurological deficit rates were similar between each intervention group versus observation. CONCLUSIONS Embolization and surgery for unruptured high-grade dAVFs afforded a greater likelihood of obliteration than did observation. Embolization also reduced the risk of death and dAVF-associated hemorrhage compared with conservative management over a modest follow-up period. These findings support embolization as the first-line treatment of choice for appropriately selected unruptured Borden type II and III dAVFs.
Article
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.
Article
OBJECTIVE Current evidence suggests that intracranial dural arteriovenous fistulas (dAVFs) without cortical venous drainage (CVD) have a benign clinical course. However, no large study has evaluated the safety and efficacy of current treatments and their impact over the natural history of dAVFs without CVD. METHODS The authors conducted an analysis of the retrospectively collected multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database. Patient demographics and presenting symptoms, angiographic features of the dAVFs, and treatment outcomes of patients with Borden type I dAVFs were reviewed. Clinical and radiological follow-up information was assessed to determine rates of new intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit (NHND), worsening of venous hyperdynamic symptoms (VHSs), angiographic recurrence, and progression or spontaneous regression of dAVFs over time. RESULTS A total of 342 patients/Borden type I dAVFs were identified. The mean patient age was 58.1 ± 15.6 years, and 62% were women. The mean follow-up time was 37.7 ± 54.3 months. Of 230 (67.3%) treated dAVFs, 178 (77%) underwent mainly endovascular embolization, 11 (4.7%) radiosurgery alone, and 4 (1.7%) open surgery as the primary modality. After the first embolization, most dAVFs (47.2%) achieved only partial reduction in early venous filling. Multiple complementary interventions increased complete obliteration rates from 37.9% after first embolization to 46.7% after two or more embolizations, and 55.2% after combined radiosurgery and open surgery. Immediate postprocedural complications occurred in 35 dAVFs (15.2%) and 6 (2.6%) with permanent sequelae. Of 127 completely obliterated dAVFs by any therapeutic modality, 2 (1.6%) showed angiographic recurrence/recanalization at a mean of 34.2 months after treatment. Progression to Borden-Shucart type II or III was documented in 2.2% of patients and subsequent development of a new dAVF in 1.6%. Partial spontaneous regression was found in 22 (21.4%) of 103 nontreated dAVFs. Multivariate Cox regression analysis demonstrated that older age, NHND, or severe venous-hyperdynamic symptoms at presentation and infratentorial location were associated with worse prognosis. Kaplan-Meier curves showed no significant difference for stable/improved symptoms survival probability in treated versus nontreated dAVFs. However, estimated survival times showed better trends for treated dAVFs compared with nontreated dAVFs (288.1 months vs 151.1 months, log-rank p = 0.28). This difference was statistically significant for treated dAVFs with 100% occlusion (394 months, log-rank p < 0.001). CONCLUSIONS Current therapeutic modalities for management of dAVFs without CVD may provide better symptom control when complete angiographic occlusion is achieved.
Article
OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are often treated with endovascular therapy, but occasionally a multimodality approach including surgery and/or radiosurgery is utilized. Recurrence after an initial angiographic cure has been reported, with estimated rates ranging from 2% to 14.3%, but few risk factors have been identified. The objective of this study was to identify risk factors associated with recurrence of dAVF after putative cure. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) data were retrospectively reviewed. All patients with angiographic cure after treatment and subsequent angiographic follow-up were included. The primary outcome was recurrence, with risk factor analysis. Secondary outcomes included clinical outcomes, morbidity, and mortality associated with recurrence. Risk factor analysis was performed comparing the group of patients who experienced recurrence with those with durable cure (regardless of multiple recurrences). Time-to-event analysis was performed using all collective recurrence events (multiple per patients in some cases). RESULTS Of the 1077 patients included in the primary CONDOR data set, 457 met inclusion criteria. A total of 32 patients (7%) experienced 34 events of recurrence at a mean of 368.7 days (median 192 days). The recurrence rate was 4.5% overall. Kaplan-Meier analysis predicted long-term recurrence rates approaching 11% at 3 years. Grade III dAVFs treated with endovascular therapy were statistically significantly more likely to experience recurrence than those treated surgically (13.3% vs 0%, p = 0.0001). Tentorial location, cortical venous drainage, and deep cerebral venous drainage were all risk factors for recurrence. Endovascular intervention and radiosurgery were associated with recurrence. Six recurrences were symptomatic, including 2 with hemorrhage, 3 with nonhemorrhagic neurological deficit, and 1 with progressive flow-related symptoms (decreased vision). CONCLUSIONS Recurrence of dAVFs after putative cure can occur after endovascular treatment. Risk factors include tentorial location, cortical venous drainage, and deep cerebral drainage. Multimodality therapy can be used to achieve cure after recurrence. A delayed long-term angiographic evaluation (at least 1 year from cure) may be warranted, especially in cases with risk factors for recurrence.
Conference Paper
Background Current evidence suggests that intracranial dural arteriovenous fistulas (dAVFs) lacking cortical venous drainage (CVD) have a benign clinical course. However, there is no large study evaluating the safety/efficacy of current treatments and their impact over the natural history of no-CVD dAVFs. Methods We conducted an analysis of the retrospectively collected multi-center Consortium for dAVF Outcomes Research (CONDOR) database. Demographics, presenting symptoms, dAVFs’ angiographic features and therapeutic intervention/complications data of patients with Borden-Shucart type 1 dAVFs were reviewed. Clinical and radiological follow-up information was assessed to determine rates of new intracranial hemorrhage or non-hemorrhagic neurological deficit (NHND), worsening of venous hyperdynamic symptoms (VHS), angiographic recurrence, progression or spontaneous regression of dAVFs over time. Results A total of 368 patients/Borden-Shucart type I dAVFs were identified. For patients with multiple dAVFs, only the largest one was included in the analysis. Mean age was 57.9±15.6 years, and 60.9% were women. Mean follow-up time was 40.1±45.2 months. The most common location was the transverse/sigmoid sinus (50.3%). Of 240 treated dAVFs, 224 (93.3%) underwent endovascular embolization, 11 (4.9%) radiosurgery alone and 5 (2.1%) open surgery as primary modality. After first embolization, most dAVFs (45.5%) achieved only partial reduction in early venous filling. Multiple complementary interventions increased complete obliteration rates from 37.5% after first embolization to 45.5% after 2 or more embolizations, and 53.8% after complimentary radiosurgery/open surgery. Immediate post-procedural complications occurred in 38 treated dAVFs (15.8%) and 7 with permanent sequelae. Of 129 completely obliterated dAVFs by any therapeutic modality, 3 (2.3%) showed angiographic recurrence/recanalization in a mean time of 10 months after treatment. Progression to Borden-Shucart types II-III was documented in 2.4% and subsequent development of new dAVF in 1.5%. Partial spontaneous regression was found in 24 out of 115 non-treated dAVFs with follow-up available (20.9%). Multivariate Cox regression analysis demonstrated that NHND or severe VHS at presentation and infratentorial location were associated with worse prognosis. Kaplan-Meier curves demonstrated no significant difference for stable/improved symptoms survival probability in treated versus non-treated dAVFs. However, estimated survival times showed better trends for treated dAVFs compared with non-treated dAVFs (179.2 months vs 163 months, Log-rank p-value = 0.12). This difference was statistically significant for treated dAVFs with 100% occlusion compared with partially-occluded dAVFs (173.2 months vs 143.9 months, Log-rank p-value < 0.001). • Download figure • Open in new tab • Download powerpoint Abstract E-031 Figure 1 Subgroup Kaplan-Meier survival analysis for treated type I dAVFs that achieved complete angiographic obliteration Conclusion Current therapeutic modalities for management of dAVFs without CVD are safe and may provide better symptom control when complete angiographic occlusion can be achieved. Disclosures E. Samaniego 1; C; SVIN 2019, Bee Foundation 2019. 2; C; Medtronic, MicroVention. J. Roa None. M. Hayakawa None. S. Ortega-Gutierrez 2; C; Stryker, Medtronic. R. Guniganti None. D. Bulters None. A. Alaraj None. S. Amin-Hanjani None. G. Lanzino None. G. Zipfel None. D. Hasan None. C. Derdeyn None.
Article
OBJECTIVE The rarity of cerebral dural arteriovenous fistulas (dAVFs) has precluded analysis of their natural history across large cohorts. Investigators from a considerable proportion of the few reports that do exist have evaluated heterogeneous groups of untreated and partially treated lesions. In the present study, the authors exclusively evaluated the untreated course of dAVFs across a multi-institutional data set to delineate demographic, angiographic, and natural history data. METHODS A multi-institutional database of dAVFs was queried for demographic and angiographic data as well as untreated disease course. After dAVFs were stratified by Djindjian type, annual nonhemorrhagic neurological deficit (NHND) and hemorrhage rates were derived, as were risk factors for each. A multivariable Cox proportional-hazards regression model was used to calculate hazard ratios. RESULTS Two hundred ninety-five dAVFs had at least 1 month of untreated follow-up. For 126 Type I dAVFs, there were no episodes of NHND or hemorrhage over 177 lesion-years. Respective annualized NHND and hemorrhage rates were 4.5% and 3.4% for Type II, 6.0% and 4.0% for Type III, and 4.5% and 9.1% for Type IV dAVFs. The respective annualized NHND and hemorrhage rates were 2.3% and 2.9% for asymptomatic Type II–IV dAVFs, 23.1% and 3.3% for dAVFs presenting with NHND, and 0% and 46.2% for lesions presenting with hemorrhage. On multivariate analysis, NHND presentation (HR 11.49, 95% CI 3.19–63) and leptomeningeal venous drainage (HR 5.03, 95% CI 0.42–694) were significant risk factors for NHND; hemorrhagic presentation (HR 17.67, 95% CI 2.99–117) and leptomeningeal venous drainage (HR 10.39, 95% CI 1.11–1384) were significant risk factors for hemorrhage. CONCLUSIONS All Type II–IV dAVFs should be considered for treatment. Given the high risk of rebleeding, lesions presenting with NHND and/or hemorrhage should be treated expediently.
Article
Intracranial dural arteriovenous fistulae (dAVFs) are typified by pathological anastomoses between meningeal arteries and dural venous sinuses or cortical veins. These fistulae frequently reside within the dural leaflets surrounding a venous sinus, characteristically at the transverse-sigmoid junction but also at the cavernous sinus (CS), superior sagittal sinus, anterior cranial fossa, tentorium, and other locations. dAVFs are distinguished from their pial counterparts (eg, arteriovenous malformations) by their arterial supply from vessels that perfuse the dura mater and lack of a parenchymal nidus.1 dAVFs are rare lesions, accounting for 10% to 15% of all intracranial vascular malformations: 6% of supratentorial and 35% of infratentorial vascular malformations.2 Most frequently, dAVFs affect patients in their middle-to-later years of life (eg, 50–60 years of age).3 Less commonly, dAVFs occur in younger age groups, including children. There is neither a clear sex predilection nor genetic component to these lesions. Clinical manifestations vary widely and depend on both the hemodynamic properties and location of the fistula. Multiple classification systems have been proposed in an effort to predict which dAVFs are at high risk for new neurological events. Most of these schemes stratify risk based on angiographic appearance of the dAVFs, in particular involvement of a venous sinus and presence or absence of retrograde cortical venous drainage (CVD). Other schemes combine angiographic appearance with mode of presentation, given the impact symptoms related to intracerebral hemorrhage (ICH) and nonhemorrhagic neurological deficits (NHND) have on dAVF natural history.4–6 In the following review and synthesis, the authors describe the pathophysiology, classification, mode of presentation, imaging characteristics, natural history, and therapeutic armamentarium for intracranial dAVFs. Particular attention will be given to recent evidence that certain clinical and angiographic features of dAVFs can be used to help stratify risk of future ICH and NHND in an effort …
Article
Background and purpose: The introduction of liquid embolic agents has revolutionized endovascular approach to cranial vascular malformations. The aim of the study was to retrospectively assess the efficacy and safety of Precipitating Hydrophobic Injectable Liquid (PHIL), a new nonadhesive liquid embolic agent, in the treatment of patients with cranial dural arteriovenous fistulas. The primary end point was the rate of complete occlusion of dural arteriovenous fistulas. Secondary end points included the incidence of adverse events and clinical status at 3-month follow-up. Materials and methods: This was a retrospective multicenter study. Twenty-six consecutive patients with dural arteriovenous fistulas (de novo or previously treated) treated by injection of PHIL only or with PHIL in combination with other embolization products (such as Onyx or detachable coils) were included in the study. Recruitment started in August 2014 and ended in September 2015. Results: Twenty-two (85%) patients were treated with PHIL only, with 3 patients treated with both PHIL and Onyx, and 1, with both PHIL and coils. Immediate complete angiographic occlusion was achieved in 20 (77%) patients. Of the 6 patients with residual fistulas, 3 were retreated with PHIL and 1 achieved angiographic cure. An adverse event was seen in 1 patient who developed worsening of preexisting ataxia due to acute thrombosis of the draining vein. Conclusions: PHIL appears to be safe and effective for endovascular treatment of cranial dural arteriovenous fistulas. Short-term angiographic and clinical results are comparable with those of Onyx, with the added advantage of easier preparation and improved homogeneous cast visualization. The use of iodine as a radio-opacifier also produces considerably less artifacts on CT compared with tantalum-based embolic materials.
Chapter
Background and Purpose There are few reports describing the prevalence of dural arteriovenous fistulas (dAVFs). We conducted a nation-wide retrograde survey on the clinical frequency and the status of treatment of dAVFs in Japan. Methods The first questionnaire was sent to 1,236 certified neurosurgery clinics in Japan to ask about the number of patients treated and the location of dAVF during the 5 years from 1998 to 2002. The second questionnaire was sent to 102 large-volume centers to ask the patients’ ages, gender, location of the fistula, clinical presentation, treatment modalities, clinical and radiological results, and recurrence. Results In the first survey, 1,815 cases were chosen from 338 clinics, including 826 cavernous sinus, 514 transverse-sigmoid sinus, 105 spinal, and 370 lesions in other places. The estimated detection rate was 0.29 per 100,000 persons per year in Japan. In the second survey, there were 1,490 cases (mean age: 62.7 ; 628 men and 850 women) that were culled from 68 high-volume centers. The initial clinical presentation was ocular symptoms (45 % of the cases), tinnitus (20 %), intracranial hemorrhage (16 %), and non-hemorrhagic neurological deficits (20 %). Treatment modality was endovascular therapy (76 % of the patients), open surgery (13 %), irradiation (3.4 %), and conservative therapy (11 %). Angiographic results were total obliteration in 59 % of the patients and subtotal obliteration in 16 %. Clinical symptoms disappeared in 54 % of the patients, improved in 16 %, unchanged in 7 %, worsened in 1.5 %, and death occurred in 1.2 %. Recurrence was reported in 5.9 % of the patients. Conclusions This survey delineated the clinical frequency and the epidemiologic features of dAVF in Japan.
Article
Tentorial dural arteriovenous fistulas are characterized by a high hemorrhagic risk. We evaluated trends in outcomes and management of tentorial dural arteriovenous fistulas and performed a meta-analysis evaluating clinical and angiographic outcomes by treatment technique. We performed a comprehensive literature search for studies on surgical and endovascular treatment of tentorial dural arteriovenous fistulas. We compared the proportion of patients undergoing endovascular, surgical, and combined endovascular/surgical management; the proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas; and proportion of patients with good neurologic outcome across 3 time periods: 1980-1995, 1996-2005, and 2006-2014. We performed a random-effects meta-analysis, evaluating the rates of occlusion, long-term good neurologic outcome, perioperative morbidity, and resolution of symptoms for the 3 treatment modalities. Twenty-nine studies with 274 patients were included. The proportion of patients treated with surgical treatment alone decreased from 38.7% to 20.4% between 1980-1995 and 2006-2014. The proportion of patients treated with endovascular therapy alone increased from 16.1% to 48.0%. The proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas decreased from 64.4% to 43.6%. The rate of good neurologic outcome increased from 80.7% to 92.9%. Complete occlusion rates were highest for patients receiving multimodality treatment (84.0%; 95% CI, 72.0%-91.0%) and lowest for endovascular treatment (71.0%; 95% CI, 56.0%-83.0%; P < .01). Long-term good neurologic outcome was highest in the endovascular group (89.0%; 95% CI, 80.0%-95.0%) and lowest for the surgical group (73.0%; 95% CI, 51.0%-87.0%; P = .03). Patients with tentorial dural arteriovenous fistulas are increasingly presenting with unruptured lesions, being treated endovascularly, and experiencing higher rates of good neurologic outcomes. Endovascular treatment was associated with superior neurologic outcomes but lower occlusion rates. © 2015 American Society of Neuroradiology.
Article
A 43-year-old man presented with acute subarachnoid hemorrhage. He was investigated and found to have a rare posterior condylar canal dural arteriovenous fistula (DAVF). DAVFs of the posterior condylar canal are rare. Venous drainage of the DAVF was through a long, tortuous, and aneurysmal bridging vein. We describe the clinical presentation, cross sectional imaging, angiographic features, and endovascular management of this patient. The patient was treated by transarterial embolization of the fistula through the ascending pharyngeal artery. This is the first report of an acutely bled posterior condylar canal DAVF treated by transarterial Onyx embolization with balloon protection in the vertebral artery. The patient recovered without any neurological deficit and had an excellent outcome. On 6 month follow-up angiogram, there was stable occlusion of the dural fistula.
Article
We developed the Japanese Registry of Neuroendovascular Therapy 2 (JR-NET2) database and used the information for a retrospective, nation-wide multicenter, observational study to clarify the clinical characteristics, current status of procedures, and outcome of patients treated by neuroendovascular therapy in Japan. In this report, we analyzed the clinical characteristics of dural arteriovenous fistulas (dAVFs) in the JR-NET2 database. All patients with dAVFs treated with endovascular therapy in 150 Japanese hospitals were included. Patient characteristics, clinical presentations, and imaging characteristics were analyzed. A total of 1,075 patients with dAVFs underwent 1,520 endovascular procedures. Of 1,075 patients, 45% were men and 55% were women. The mean age was 65 ± 13 years. The most frequent location of dAVFs was the cavernous sinus (43.6%), followed by the transverse-sigmoid sinus (TSS) (33.4%). Twelve percent of the patients had intracranial hemorrhage, 9% had venous infarction, and 3% had convulsion. The statistically significant independent risk factors of intracranial hemorrhage were TSS, superior sagittal sinus (SSS), tentorium, anterior cranial fossa, cranio-cervical junction, cortical venous reflux (CVR), and varix. Risk factors of venous infarction were age older than 60 years, male sex, TSS, SSS, and CVR. Risk factors of convulsion were male sex, SSS, and CVR. This is the largest nationwide report, to date, of the clinical characteristics of dAVFs treated by neuroendovascular therapy. CVR was a major risk factor of aggressive symptoms.
Article
51-year-old man with a history of hyperlipidemia presented to the outpatient internal medicine clinic with a 3-week history of tinnitus. He described a “whoosh-whoosh” sound in his right ear that was constant and that increased in intensity with exertion. It was increasing in severity duringtheprevious3weeksandwasassociated with a new-onset, progressive, right-sided headache.Theheadachewasstabbinginnature and occasionally awakened him from sleep. He denied hearing loss, vertigo, vision changes, syncope, and recent illness or trauma. His medications included acetaminophen and naproxen as needed. He had a smoking history of10pack-years,withcessation13yearsbefore presentation; acknowledged drinking 1 to 2 alcoholic beverages per day; denied illicit drug use; and worked as a salesman driving 250 miles per day. On examination, the patient was afebrile, with a blood pressure of 129/82 mm Hg, a pulse rate of 68 beats/min, and a respiratory rate of 18 breaths/min. He appeared comfortable and in no acute distress. He had no scleral injection, and results of funduscopic examination were normal. The external auditory canals and tympanic membranes were visualized and normal bilaterally. Results of Weber and Rinne testing were normal. Cranial nerves II to XII were otherwise intact bilaterally, and the results of the remainder of the neurologic examination were within normal limits. No carotid bruits were auscultated. Heart, lung, abdominal, and lymphatic examination findings were unremarkable.
Article
Object: In this paper the authors' goal was to review the clinical features and outcome of patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with hemorrhage. Methods: A retrospective study of 28 patients with DAVFs who presented with intracranial hemorrhage to 2 separate institutions was performed. The information reviewed included clinical presentation, location and size of hemorrhage, angiographic features, treatment, and clinical and radiologically documented outcomes. Clinical and radiological follow-up were available in 27 of 28 patients (mean follow-up 17 months). Results: The vast majority of patients were male (86%), and the most common presenting symptom was sudden-onset headache. All DAVFs had cortical venous drainage, and about one-third were associated with a venous varix. The most common location was tentorial (75%). Treatment ranged from endovascular (71%), surgical (43%), Gamma Knife surgery (4%), or a combination of modalities. The majority of fistulas (75%) were completely obliterated, and most patients experienced excellent clinical outcome (71%, modified Rankin Scale score of 0 or 1). There were no complications in this series. Conclusions: Case series, including the current one, suggest that the vast majority of patients who present with intracranial hemorrhage from a DAVF are male. The most common location for DAVFs presenting with hemorrhage is tentorial. Excellent outcomes are achieved with individualized treatment, which includes various therapeutic strategies alone or in combination. Despite the hemorrhagic presentation, almost two-thirds of patients experience a full recovery with no or minimal residual symptoms.
Article
Dural arteriovenous fistulas (DAVFs) are rare lesions. The most common locations of DAVFs are cavernous, sigmoid and transverse sinuses. Anterior cranial fossa is one of the less frequent placement for DAVFs and the risk of hemorrhage in this region is increased. Reported hemorrhage risks have been ranged from 62 to 91 %, and an aggressive clinical course is more likely than a benign clinical course. A 47-year-old man was admitted to our emergency room with headache and the computed tomography revealed frontal hemorrhage. Neurological examination was normal. We applied cerebral angiography in our interventional neurology department and an anterior cranial fossa DAVFs, supplied by bilateral ophthalmic-ethmoidal arteries, was determined. DAVFs are a rare cause of intracranial hemorrhages and in the literature anterior cranial fossa DAVFs have been reported scarcely, so that we aimed to present this rare entity.
Article
Object: Management of dural arteriovenous fistulas (DAVFs) has changed during the last decades due to increased knowledge of their pathophysiology and natural history as well as advances in treatment modalities. The authors describe the characteristics and long-term outcome of a large consecutive series of patients with DAVFs. Methods: Altogether 251 patients with 261 DAVFs were treated in 2 of the 5 neurosurgery departments at Helsinki and Kuopio University Hospitals between 1944 and 2006. Clinical data and radiological examinations were reviewed to assess patients' overall long-term clinical outcome. Results: The detection rate of DAVFs increased markedly in the 1970s and again in the 1990s when digital subtraction angiography was introduced. The incidence of DAVFs in a defined southern Finnish population was 0.51 per 100,000 individuals per year, which represents 32% of all the brain arteriovenous malformations. In the early part of the series, DAVFs were treated by proximal ligation of the feeding arteries. Later, most of the patients underwent preoperative embolization and subsequent craniotomy, and since 2000 stereotactic radiosurgery has been increasingly used in the treatment of DAVFs. Fifty-nine percent of the 261 fistulas were totally occluded. Treatment-related major complications were seen in 21 patients. Conclusions: The advances in diagnostic methods (digital subtraction angiography, CT, and MRI) increased the detection rate of DAVFs, and as treatment modalities developed, the results of treatment and outcome of patients markedly improved with the introduction of endovascular techniques and stereotactic radiosurgery. Microsurgery is of limited use in DAVFs resistant to other treatment modalities.
Article
The goal of this study was to determine the clinical course of Borden-Shucart Type I cranial dural arteriovenous fistulas (DAVFs) and to calculate the annual rate of conversion of these lesions to more aggressive fistulas that have cortical venous drainage (CVD). A retrospective chart review was conducted of all patients harboring DAVFs who were seen at the authors' institution between 1997 and 2009. Twenty-three patients with Type I DAVFs who had available clinical follow-up were identified. Angiographic and clinical data from these patients were reviewed. Neurological outcome and status of presenting symptoms were assessed during long-term follow-up. Of the 23 patients, 13 underwent endovascular treatment for intolerable tinnitus or ophthalmological symptoms, and 10 did not undergo treatment. Three untreated patients died of unrelated causes. In those who were treated, complete DAVF obliteration was achieved in 4 patients, and palliative reduction in DAVF flow was achieved in 9 patients. Of the 19 patients without radiographic cure, no patient developed intracranial hemorrhage or nonhemorrhagic neurological deficits (NHNDs), and no patient died of DAVF-related causes over a mean follow-up of 5.6 years. One patient experienced a spontaneous, asymptomatic obliteration of a partially treated DAVF in late follow-up, and 2 patients experienced a symptomatic conversion of their DAVF to a higher-grade fistula with CVD in late follow-up. The annual rate of conversion to a higher-grade DAVF based on Kaplan-Meier cumulative event-free survival analysis was 1.0%. The annual rate of intracranial hemorrhage, NHND, and DAVF-related death was 0.0%. A small number of Type I DAVFs will convert to more aggressive DAVFs with CVD over time. This conversion to a higher-grade DAVF is typically heralded by a change in patient symptoms. Follow-up vascular imaging is important, particularly in the setting of recurrent or new symptoms.
Article
Hemorrhage from cerebral dural arteriovenous fistulae (dAVF) is a considerable source of neurological morbidity and even mortality. To evaluate the natural history of cerebral dAVF. We reviewed our own cohort of 70 dAVF and incorporated results from the literature, synthesizing pooled hemorrhage rates and evaluating risk factors for 395 dAVF in 6 studies. No hemorrhages occurred during 409 lesion-years of follow-up of Borden type I dAVF; however, cortical venous drainage developed in 1.4%. Like type I dAVF, type II dAVF demonstrated a female predilection and were most commonly transverse-sigmoid or cavernous. Eighteen percent of type II dAVF presented with hemorrhage (95% confidence interval [CI]: 8%-36%), and the annual hemorrhage rate was 6% (95% CI: 0.1%-19%). Borden type III dAVF demonstrated a male predilection and were most commonly tentorial or petrosal. Thirty-four percent presented with hemorrhage (95% CI: 0.4%-49%), with an annual hemorrhage rate of 10% (95% CI: 4%-20%), increasing to 21% for those with venous ectasia (95% CI: 4%-66%). The hemorrhage rate decreased to 2% for asymptomatic or minimally symptomatic type II or III dAVF (95% CI: 0.2%-8%), and increased to 10% for those presenting with nonhemorrhagic neurological deficits (95% CI: 0.9%-41%) and to 46% for those presenting with hemorrhage (95% CI: 11%-130%). Venous ectasia is a significant risk factor for hemorrhage among dAVF with cortical venous drainage. In addition, those with hemorrhagic presentation, even compared with nonhemorrhagic neurological deficit presentation, as well as Borden type III dAVF compared with type II dAVF demonstrated a trend toward greater hemorrhage rates.
Article
A 61-year-old woman presented with painful ophthalmoplegia, Tolosa-Hunt syndrome. The patient had undergone a placement of dental implant 5 months before the presentation and had a local maxillary sinusitis 1 month later. She had not been aware of any preceding head trauma or infection. On examination, the patient showed serious right oculomotor nerve paresis and retro-orbital pain. Blood examination showed normal findings. Magnetic resonance imaging identified abnormal structure in the right cavernous sinus with flow void signals. Angiography revealed a carotid cavernous sinus fistula fed by the intracavernous branches of the internal carotid artery on both sides, right internal maxillary and middle meningeal arteries, and left ascending pharyngeal artery. The patient underwent coil embolization via both external carotid arteries. We assumed that local maxillary sinusitis caused by dental implant might spread hematogenously into the sphenoid and cavernous sinuses and formed a carotid cavernous sinus fistula, which presented with Tolosa-Hunt syndrome. Implant-associated infection has to be managed promptly with adequate manner before it spreads.
Article
The quoted risk of hemorrhage from dural arteriovenous fistulae with cortical venous reflux varies widely, and the influence of angiographic grade on clinical course has not previously been reported. To assess the risk of hemorrhage and the influence of angiographic grade on this risk, compared with known predictors of hemorrhage such as presentation. Seventy-five fistulae with cortical venous reflux identified in our arteriovenous malformations clinic between 1992 and 2007 were followed up clinically, and their angiograms were reviewed. There were 8 hemorrhages in 90 years of follow-up. The annual incidence of hemorrhage before any treatment was 13%, and 4.7% after partial treatment, giving an overall incidence of 8.9% before definitive treatment. Borden and Cognard grades were poor discriminators of risk for lesions with the exception of Cognard type IV lesions. These lesions, characterized by venous ectasia, had a 7-fold increase in the incidence of hemorrhage (3.5% no ectasia vs 27% with ectasia). Patients presenting with hemorrhage (20%) or nonhemorrhagic neurological deficit (22%) had a higher incidence of hemorrhage than those with a benign presentation (4.3%), but this may be directly linked to the presence of venous ectasia. In this series untreated dural arteriovenous fistulae with cortical venous reflux had a 13% annual incidence of hemorrhage after diagnosis. There was a significant difference between those with and without venous ectasia. This should be confirmed by further studies, but probably defines a high-risk subgroup of patients that requires rapid intervention.
Article
A 58-year-old man presented with sudden onset of severe headache. Computed tomography demonstrated subarachnoid hemorrhage and right acute subdural hematoma. He had no neurological deficits. Cerebral angiography showed an anterior cranial fossa dural arteriovenous fistula (AVF) supplied by the bilateral ethmoidal arteries. A fistula was suggested on the right side, and the dural AVF drained into the superior sagittal sinus via the bilateral frontal cortical veins. Venous varix was observed at both drainage sites. Bifrontal craniotomy with right-side dural incision was performed and the fistula was interrupted. Postoperative angiography demonstrated a persistent fistula draining into the left cortical vein. Nineteen days later, bifrontal craniotomy with left-side dural incision was performed and the draining vein was completely coagulated with the aid of intraoperative angiography. Postoperatively, there was no detectable residual fistula. He was discharged without neurological deficits 2 weeks after surgery. The present case of anterior cranial fossa dural AVF with bilateral cortical drainers shows that drainer occlusion at two points may be needed for complete obliteration of the drainers because the fistulous connection may not be simple.
Article
This is the first report of an aggressive dural arteriovenous fistula presenting with rhinorrhea. It demonstrates the importance of recognizing increased intracranial pressure, and its underlying cause, as the predisposing factor to a spontaneous cerebrospinal fluid leak because this carries implications for management. Ten years after minor trauma and directly after an intercontinental flight, a 43-year-old woman presented with rhinorrhea. Right-sided pulsatile tinnitus had been present for the past 9 years. Imaging demonstrated an intracranial dural arteriovenous fistula of the right transverse sinus with cortical venous reflux. Magnetic resonance imaging findings indicated long-standing increased intracranial pressure. The fistula was treated by endovascular means, using both transvenous and transarterial approaches, which led to immediate relief of the tinnitus and resolution of the rhinorrhea within 4 days. A dural arteriovenous fistula should be included in the differential diagnosis of underlying causes of increased intracranial pressure when examining a patient with a cerebrospinal fluid leak. Treatment of the fistula should precede attempts to treat the rhinorrhea, especially if the fistula has cortical venous reflux.
Article
We describe a case of an acute confusional state associated with a right parietal dural arteriovenous fistula. A 67-year-old man in his usual state of health experienced an acute confusion episode preceded by a valsalva maneuver. The episode lasted approximately 60 minutes. Afterward he was able to remember everything that occurred. A magnetic resonance imaging scan suggested a right parietal dural arteriovenous fistula, which was confirmed by angiography. A seizure was ruled out by clinical examination and an electroencephalogram. The patient underwent therapeutic embolization and surgical ligation of the fistula. Feeding vessels to the malformation were cauterized within the leaves of the falx, and the draining vein was clipped with a titanium aneurysm clip and divided. An intraoperative angiogram was then performed, which showed obliteration of the fistula. There was no demonstrable confusion or memory loss noted postoperatively. We propose that venous hypertension from the dural arteriovenous fistula in combination with a valsalva maneuver caused ischemia in the right parietal lobe, eliciting a deficit in attention.
Article
This article presents a modification to the existing classification scales of intracranial dural arteriovenous fistulas based on newly published research regarding the relationship of clinical symptoms and outcome. The 2 commonly used scales, the Borden-Shucart and Cognard scales, rely entirely on angiographic features for categorization. The most critical anatomical feature is the identification of cortical venous drainage (CVD; Borden-Shucart Types II and III and Cognard Types IIb, IIa + b, III, IV, and V), as this feature identifies lesions at high risk for future hemorrhage or ischemic neurological injury. Yet recent data has emerged indicating that within these high-risk groups, most of the risk for future injury is in the subgroup presenting with intracerebral hemorrhage or nonhemorrhagic neurological deficits. The authors have defined this subgroup as symptomatic CVD. Patients who present incidentally or with symptoms of pulsatile tinnitus or ophthalmological phenomena have a less aggressive clinical course. The authors have defined this subgroup as asymptomatic CVD. Based on recent data the annual rate of intracerebral hemorrhage is 7.4-7.6% for patients with symptomatic CVD compared with 1.4-1.5% for those with asymptomatic CVD. The addition of asymptomatic CVD or symptomatic CVD as modifiers to the Borden-Shucart and Cognard systems improves their accuracy for risk stratification of patients with high-grade dural arteriovenous fistulas.
Article
The authors report their preliminary experience using a balloon-assisted technique (BAT) in the transarterial embolization of intracranial dural arteriovenous fistulas (DAVFs). The authors reviewed the prospectively collected data obtained in 7 consecutive patients with DAVFs in whom embolization was achieved using transarterially injected Onyx with either the venous or arterial BAT. Procedures were performed at the Division of Interventional Neuroradiology at the University of California at Los Angeles Medical Center between September 2005 and January 2008. Three patients presented with cortical venous reflux and 4 did not. Three patients underwent transarterial Onyx-based embolization combined with transvenous balloon protection; the balloon was inflated in the transverse sinus in 2 of these patients and in the superior sagittal sinus in the third. One of them underwent an additional transarterial Onyx embolization with arterial BAT, whereas 4 other patients were treated with arterial BAT alone. The occipital artery was temporarily occluded with the balloon in 4 of these cases, whereas in the fifth, the authors used temporary balloon occlusion of the middle meningeal artery. Angiograms obtained immediately after embolization demonstrated complete or near-complete obliteration of the fistula in 6 patients and partial occlusion in 1 patient. There were no immediate or postprocedural complications. Two patients who presented with intracranial hemorrhage never suffered a second hemorrhage, and all other patients experienced either complete resolution or significant improvement of their symptoms. The BAT provides a new complementary method in the transarterial embolization of DAVFs that are not amenable to transvenous embolization. The venous BAT protects the patency of critical venous pathways, whereas the arterial BAT provides better control of the Onyx-based embolization.
Article
Dural arteriovenous fistula (DAVF) is generally recognized as an acquired lesion; however, its epidemiology, etiology, and natural history are yet to be completely elucidated. Recently, an epidemiological survey of the detected DAVF cases in Japan between 1998 and 2002 was conducted. The detection rate of DAVF per 100,000 adults per year is 0.29 for DAVF. Furthermore, unlike Europe and North America where cases of transverse-sigmoid sinus DAVF are predominantly detected, in Japan, a higher number of cases of cavernous sinus lesions are detected, indicating racial difference in the presentation of DAVF. Our study indicates that dural sinus thrombosis, which is generally considered as a causative factor of DAVF, is less likely to precede the detection of DAVF. A possible mechanism underlying the formation of DAVF is as follows: subtle changes, including minor trauma, cause the formation of an abnormal arteriovenous shunt in the dura and promote progressive steno-occlusive change in its venous drainage.
Article
The natural history of cranial dural arteriovenous malformations (AVM's) is highly variable. The authors present their clinical experience with 17 dural AVM's in adults, including 10 cases with an aggressive neurological course (strictly defined as hemorrhage or progressive focal neurological deficit other than ophthalmoplegia). Two of these 10 patients died prior to surgical intervention and a third was severely disabled by intracerebral hemorrhage. Six patients underwent surgical resection of their dural AVM, with preparatory embolization in two cases. One patient received embolization and radiation therapy without surgery. Six of the seven cases without an aggressive neurological course were treated conservatively, and the seventh patient underwent embolization of a cavernous sinus dural AVM because of worsening ophthalmoplegia. In order to clarify features associated with aggressive behavior, a comprehensive meta-analysis was performed on 360 additional dural AVM's reported in the literature with sufficiently detailed clinical and angiographic information. The location and angiographic features of 100 aggressive cases were compared to those of 277 benign cases. No location of dural AVM's was immune from aggressive neurological behavior; however, an aggressive neurological course was least often associated with cases involving the transverse-sigmoid sinuses and cavernous sinus and most often associated with cases at the tentorial incisura. Contralateral contribution to arterial supply and rate of shunting (high vs. low flow) did not correlate with aggressive neurological behavior as defined. Leptomeningeal venous drainage, variceal or aneurysmal venous dilations, and galenic drainage correlated significantly (p less than 0.05) with aggressive neurological presentation. The latter three angiographic features often coexisted in the same dural AVM. It is concluded that these features significantly increase the natural risk of dural AVM's, and warrant a more vigilant therapeutic strategy.
Article
Twenty-eight patients with dural arteriovenous malformations, mostly located along the cranial base and in the occipitomastoid region, were studied angiographically. It was often possible to define a relationship between the clinical syndrome and the angiographic pattern of venous drainage. Intracranial hemorrhages occurred in those patients in whom the venous drainage of the arteriovenous malformation was limited to the pial veins, while the syndrome of a cavernous sinus fistula was present when retrograde venous drainage from the anomaly extended through the distensible ophthalmic veins. If the venous outflow was antegrade through the usual channels, the clinical syndrome reflected only the presence and volume of the arteriovenous shunt.
Article
A classification is proposed that unifies and organizes spinal and cranial dural arteriovenous fistulous malformations (AVFMs) into three types based upon their anatomical similarities. Type I dural AVFMs drain directly into dural venous sinuses or meningeal veins. Type II malformations drain into dural sinuses or meningeal veins but also have retrograde drainage into subarachnoid veins. Type III malformations drain into subarachnoid veins and do not have dural sinus or meningeal venous drainage. The arterial supply in each of these three types is derived from meningeal arteries. The anatomical basis of the proposed classification is presented with several cases that illustrate the three types of dural AVFMs. A rationale for the treatment of spinal and cranial dural AVFMs according to their anatomical characteristics is discussed.
Article
To review the symptoms and progression of dural arteriovenous fistulas (AVFs) and correlate the findings with various angiographic patterns. Patterns of venous drainage allowed classification of dural AVFs into five types: type I, located in the main sinus, with antegrade flow; type II, in the main sinus, with reflux into the sinus (IIa), cortical veins (IIb), or both (IIa + b); type III, with direct cortical venous drainage without venous ectasia; type IV, with direct cortical venous drainage with venous ectasia; and type V, with spinal venous drainage. Type I dural AVFs had a benign course. In type II, reflux into the sinus induced intracranial hypertension in 20% of cases, and reflux into cortical veins induced hemorrhage in 10%. Hemorrhage was present in 40% of cases of type III dural AVFs and 65% of type IV. Type V produced progressive myelopathy in 50% of cases. This classification provides useful data for determination of the risk with each dural AVF and enables decision-making about the appropriate therapy.
Article
Cranial dural arteriovenous fistulae (AVF's) of the tentorial incisura or the dura of the middle fossa have a much higher incidence of draining via leptomeningeal veins than do AVF's of the transverse-sigmoid sinuses or the cavernous sinus. Such a drainage pattern is associated with an increased incidence of intracranial hemorrhage and progressive focal neurological deficits. Patients with cranial dural AVF's often undergo surgical excision and/or endovascular embolization for elimination of the AVF. Since these lesions are frequently large and involve the skull base or adjacent dural sinuses, extensive surgery is often required. In contrast, spinal dural AVF's with only intradural venous drainage to the medullary venous system are treated successfully by simply interrupting the vein that drains the dural AVF as it enters the subarachnoid space. The authors identified a subgroup of patients with cranial dural AVF's in whom the AVF was drained only by leptomeningeal veins, and sought to establish whether simple interruption of the vein draining the blood from the AVF into the subarachnoid space is effective and lasting treatment in this subgroup of patients, as it is in patients with spinal dural AVF's. Four adult patients with symptomatic cranial dural AVF's (two petrotentorial, one middle fossa floor, and one posterior fossa base) were identified on arteriography as having fistulae that were supplied by the internal and/or external carotid arteries and drained only via leptomeningeal veins (two entered the petrosal vein, one a cerebellar hemispheric vein, and one a mesencephalic vein). All patients underwent interruption of the vein draining the dural AVF as it penetrated the dura to enter the subarachnoid space, and experienced neurological improvement after surgery. Repeat arteriography at 1 to 2 weeks (three patients), 3 months (3 patients), 12 to 15 months (three patients), and 4 years (two patients) revealed no residual AVF and no evidence of abnormal blood flow. Many cranial dural AVF's with leptomeningeal venous drainage (the type with the most aggressive behavior) are drained only by leptomeningeal veins. This subgroup of patients can be identified by selective arteriography and requires only interruption of the draining vein as it enters the subarachnoid space for successful, lasting elimination.
Article
Meta-analyses are now widely used to provide evidence to support clinical strategies. However, large randomized, controlled trials are considered the gold standard in evaluating the efficacy of clinical interventions. We compared the results of large randomized, controlled trials (involving 1000 patients or more) that were published in four journals (the New England Journal of Medicine, the Lancet, the Annals of Internal Medicine, and the Journal of the American Medical Association) with the results of meta-analyses published earlier on the same topics. Regarding the principal and secondary outcomes, we judged whether the findings of the randomized trials agreed with those of the corresponding meta-analyses, and we determined whether the study results were positive (indicating that treatment improved the outcome) or negative (indicating that the outcome with treatment was the same or worse than without it) at the conventional level of statistical significance (P<0.05). We identified 12 large randomized, controlled trials and 19 meta-analyses addressing the same questions. For a total of 40 primary and secondary outcomes, agreement between the meta-analyses and the large clinical trials was only fair (kappa= 0.35; 95 percent confidence interval, 0.06 to 0.64). The positive predictive value of the meta-analyses was 68 percent, and the negative predictive value 67 percent. However, the difference in point estimates between the randomized trials and the meta-analyses was statistically significant for only 5 of the 40 comparisons (12 percent). Furthermore, in each case of disagreement a statistically significant effect of treatment was found by one method, whereas no statistically significant effect was found by the other. The outcomes of the 12 large randomized, controlled trials that we studied were not predicted accurately 35 percent of the time by the meta-analyses published previously on the same topics.
Article
Cranial dural arteriovenous fistulas (DAVFs) can be classified into benign or aggressive, based on their patterns of venous drainage. A benign condition requires the absence of cortical venous drainage (CVD). The clinical and angiographic features of a consecutive single-center group of 117 patients harboring benign cranial DAVFs were evaluated over time to validate the behavior and appropriate management of these lesions. At the initial assessment four patients were asymptomatic. Two infants presented with congestive heart failure. All other patients presented with other benign symptoms: chronic headache, bruit, or orbital phenomena. Observational management was instituted in 73 patients (62%). Intolerable bruit or ophthalmological sequelae were deemed indications for palliative embolization in 43 patients and surgical treatment in one patient. A median follow-up period of 27.9 months (range 1 month-17.5 years) was available in 112 patients (95.7%), among whom repeated angiography was performed in 50. Overall, observational and palliative management resulted in a benign and tolerable level of disease in 110 (98.2%) of 112 cases. In two cases managed conservatively CVD developed. In both of these cases the conversion from benign to aggressive DAVF was associated with spontaneous progressive thrombosis of venous outlets. The disease course of a cranial DAVF without CVD is indeed benign, obviating the need for a cure of these lesions. Symptoms are well tolerated with either observation or palliative treatment. After a long-term follow-up review of 68 patients, this conservative management resulted in a benign and tolerable level of disease in 98.5% of cases. It is noteworthy, however, that a benign DAVF carries a 2% risk of developing CVD, mandating close clinical follow-up review in such cases and renewed radiological evaluation in response to any deterioration in the patient's condition.
Article
A single-institution series of 119 consecutive patients with a dural arteriovenous fistula (DAVF) and cortical venous reflux was reviewed to assess the overall clinical outcome of multidisciplinary management after long-term follow up. The selective disconnection of the cortical venous reflux compared with the obliteration of the entire DAVF was evaluated. Dural arteriovenous fistulas in patients in this series were diagnosed between 1984 and 2001, and treatment was instituted in 102 of them. The outcome of adequately treated patients was compared with that of a control group consisting of those with persistent cortical venous reflux and with data found in the literature. In cases of combined dural sinus drainage and cortical venous reflux, a novel treatment concept of selective disconnection of the cortical venous reflux that left the sinus drainage intact, and thus converted the aggressive DAVF into a benign lesion, was evaluated. Endovascular treatment, which was instituted initially in 78 patients, resulted in an obliteration or selective disconnection in 26 (25.5%) of 102 cases. In 70 cases (68.6%) the DAVFs were surgically obliterated or disconnected. In six cases (5.9%), patients were left with persistent cortical venous reflux. No lasting complications were noted in this series. Follow-up angiography confirmed a durable result in 94 (97.9%) of 96 adequately treated cases, at a mean follow up of 27.6 months (range 1.4-138.3 months). Selective disconnection was performed in 23 DAVFs with combined sinus drainage and cortical venous reflux. These patients' long-term outcomes were equal to those with obliterated DAVFs, and the complication rate was lower. Considering the ominous course of DAVFs with patent cortical venous reflux, multidisciplinary treatment of these lesions is highly effective and the complication rate is low. Selective disconnection provides a valid treatment option of DAVFs with combined dural sinus drainage and cortical venous reflux, as has been shown in cranial DAVFs with direct cortical venous reflux.
Article
The aim of this study was to assess the clinical efficacy of gamma knife surgery (GKS) in the treatment of dural arteriovenous shunts (DAVSs). From a database of more than 1600 patients with intracranial arteriovenous shunts that had been treated with GKS, the authors retrospectively and prospectively identified 53 patients with 58 DAVSs from the period between 1978 and 2003. Four patients were lost to follow-up evaluation and were excluded from the series. Thus, this study is based on the remaining 49 patients with 52 DAVSs. Thirty-six of the shunts drained into the cortical venous system, either directly or indirectly, and 22 of these were associated with intracranial hemorrhage on patient presentation. The mean prescription radiation dose was 22 Gy (range 10-28 Gy). All patients underwent a clinical follow-up examination. In 41 cases of DAVS a follow-up angiography study was performed. At the 2-year follow-up visit, 28 cases (68%) had angiographically proven obliteration of the shunt and in another 10 cases (24%) there was significant flow regression. Three shunts remained unchanged. There was one immediate minor complication related to the administration of radiation. Furthermore, one patient had a radiation-induced complication 10 years after treatment, although she recovered completely. There was one posterior fossa bleed 2 months after radiosurgery; a hematoma, as well as a lesion, was evacuated, and the patient recovered uneventfully. A second patient had an asymptomatic occipital hemorrhage approximately 6 months postradiosurgery. The clinical outcome after GKS was significantly better than that in patients with naturally progressing shunts (p < 0.01, chi-square test); figures on the latter have been reported previously. Gamma knife surgery is an effective treatment for DAVSs, with a low risk of complications. Major disadvantages of this therapy include the time elapsed before obliteration and the possibility that not all shunts will be obliterated. Cortical venous drainage from a DAVS, a risk factor for intracranial hemorrhage, is therefore a relative contraindication. Consequently, GKS can be used in the treatment of both benign DAVSs with subjectively intolerable bruit and aggressive DAVSs not responsive to endovascular treatment or surgery.
Article
Intracranial dural arteriovenous fistulae (DAVFs) can present as disabling intracranial hemorrhage. The aim of this study was to investigate the independent effects of specific demographic and clinical variables on hemorrhagic presentation in patients with DAVFs. All patients with DAVFs evaluated at the University of California at San Francisco from July 1988 through June 2004 were identified. Clinical and radiographic characteristics were recorded using a detailed abstraction form. A total of 402 patients with DAVFs were identified, 73 (18%) of whom presented with intracranial hemorrhage. Men were twice as likely to present with hemorrhage (men 70% versus women 30%, P < 0.001). Cortical venous drainage (85 versus 22%; P < 0.001), retrograde venous drainage (59 versus 36%; P < 0.001), and sinus occlusion (33 versus 18%; P = 0.004) were also more common in patients with DAVF with hemorrhagic presentation. In multivariate logistic regression analysis, cortical venous drainage (odds ratio [OR], 10.5; P < 0.001), focal neurological deficits (OR, 4.7; P < 0.001), DAVFs in the posterior fossa (OR, 4.0; P = 0.005), male sex (OR, 3.4, P = 0.001), and age older than 50 years were found to be independently associated with hemorrhagic presentation. Although DAVFs are less frequent in men than in women, they are more likely to present with hemorrhage. In addition to cortical venous drainage, a well-known risk factor for intracranial hemorrhage, posterior fossa location, older age at presentation, and focal neurological deficits were independently associated with hemorrhagic presentation in patients with DAVFs.
Characteristics and long-term outcome of 251 patients with dural arteriovenous fistulas in a defined population
  • A Piippo
  • M Niemelä
  • J Van Popta
  • Piippo A