Aggressive Dural Arteriovenous Fistulas Research Articles

Evaluation of multiple deep neural networks for detection of intracranial dural arteriovenous fistula on susceptibility weighted angiography imaging.

The natural history of intracranial dural arteriovenous fistula (DAVF) is variable and early diagnosis is crucial in order to positively impact the clinical course of aggressive DAVF. Artificial intelligence (AI) based techniques can be promising in this regard, and in this study, we used various deep neural network (DNN) architectures to determine whether DAVF could be reliably identified on susceptibility-weighted angiography images (SWAN). A total of 3965 SWAN image slices from 30 digital subtraction angiographically proven DAVF patients and 4380 SWAN image slices from 40 age-matched patients with normal MRI findings as control group were included. The images were categorized as either DAVF or normal and the data was trained using various DNN such as VGG-16, EfficientNet-B0, and ResNet-50. Various DNN architectures showed the accuracy of 95.96% (VGG-16), 91.75% (EfficientNet-B0), and 86.23% (ResNet-50) on the SWAN image dataset. ROC analysis yielded an area under the curve of 0.796 (p < .001), best for VGG-16 model. Criterion of seven consecutive positive slices for DAVF diagnosis yielded a sensitivity of 74.68% with a specificity of 69.15%, while setting eight slices improved the sensitivity to above 80.38%, with a decrease of specificity up to 56.38%. Based on seven consecutive positive slices criteria, EfficientNet-B0 yielded a sensitivity of 73.21% with a specificity of 45.92% and ResNet-50 yielded a sensitivity of 72.39% with a specificity of 67.42%. This study shows that DNN can extract discriminative features of SWAN for the classification of DAVF from normal with good accuracy, reasonably good sensitivity and specificity.

Differentiation between aggressive and benign intracranial non-cavernous dural arteriovenous fistulas using cortical venous reflux on susceptibility weighted images

PurposeThis study aimed to evaluate the ability of susceptibility-weighted imaging (SWI) to detect cortical venous reflux (CVR) in patients with intracranial non-cavernous dural arteriovenous fistulas (DAVFs), which can be helpful to differentiate benign and aggressive DAVFs. Material and MethodsTwenty-seven patients (8 women and 19 men) with 33 non-cavernous DAVFs were divided into benign and aggressive groups. Presence of CVR and pseudophlebitic pattern (PPP) and location of fistula on SWI were determined. Digital subtraction angiography was used as the reference standard. Interobserver agreement for the presence of CVR and PPP and location of DAVF on SWI was evaluated using the kappa statistic. Statistical comparisons between the benign and aggressive DAVFs were performed. ResultsSensitivity, specificity, positive predictive value, and negative predictive value of SWI for detecting CVR was 73.7%, 85.7%, 87.5%, and 70.6%, respectively. Corresponding values for detecting PPP were 95.2%, 83.3%, 95.2%, and 83.3%, respectively. SWI correctly identified DAVF location in 78.9%. Prevalence rates of CVR and PPP on SWI were significantly higher in aggressive DAVFs than benign ones. ConclusionSWI exhibited high sensitivity and specificity for detection of CVR, a characteristic used to differentiate benign and aggressive lesions. CVR and PPP on SWI are signs of aggressive DAVFs that guide to perform angiography confirmation and prompt treatment to avoid serious complication.

Non-invasive assessment of cerebral hemoglobin parameters in intracranial dural arteriovenous fistula using functional near-infrared spectroscopy-A feasibility study.

The purpose of this study was to assess the feasibility of non-invasive assessment of cerebral hemodynamics using functional near-infrared spectroscopy (fNIRS) in patients with intracranial dural arteriovenous fistula (DAVF) and to correlate the hemodynamic changes with definitive endovascular treatment. Twenty-seven DAVF patients and 23 healthy controls underwent 20-mins task-based functional near-infrared spectroscopy and neuropsychology evaluation. The mean change in the hemoglobin concentrations obtained from the prefrontal cortex was assessed for oxyhemoglobin, deoxyhemoglobin, and oxygen saturation (HbO, HbR, and SO2, respectively). The fNIRS data were analyzed and correlated with improvement in neuropsychology scores at 1-month follow-up. There was a significant reduction in HbO in the patient group, while it increased in controls (-2.57E-05 vs. 1.09E-04 mM, p < 0.001). The reduced HbO significantly improved after embolization (-2.1E-04 vs. 9.9E-04, p = 0.05, q = 0.05). In patients with aggressive DAVF (Cognard 2B and above), the change was highly significant (p < 0.001; q = 0.001). A moderate correlation was observed between MMSE scores and HbO changes (ρ = 0.4). fNIRS is a useful non-invasive modality for the assessment of DAVF, and could potentially assist in bedside monitoring of treatment response.

Transarterial Embolization of Intracranial Arteriovenous Fistulas with Large Venous Pouches in the Form of Venous Outlet Ectasia and Large Venous Varix or Aneurysm : Two Centers Experience.

ObjectiveThere are different types of cerebral vascular malformations. Pial arteriovenous fistulas (PAVFs) and dural arteriovenous fistulas (DAVFs) are two entities; they consist of one or more arterial connections to a single venous outlet without a true intervening nidus. The high turbulent flow of PAVFs and aggressive DAVFs with cortical venous reflux can result in venous outflow varix and aneurysmal dilatation. They pose a significant challenge to transvenous embolization (TVE), stereotactic radiosurgery, and surgical treatment. We aim to share our centers’ experience with the transarterial embolization (TAE) for arteriovenous fistulas (AVFs) with large venous pouches and to report the outcome. MethodsThe authors’ two institutions’ databases were retrospectively reviewed from February 2017 to February 2021. All patients with intracranial high flow PAVFs and aggressive DAVFs with venous outlet ectasia and large venous varix and were treated by TAE were included. ResultsFifteen patients harboring 11 DAVFs and four PAVFs met our inclusion criteria. All patients underwent TAE in 17 sessions. Complete angiographic obliteration was achieved after 14 sessions in 12 patients (80%). Four patients (25%) had residual after one TAE session. Technical failure was documented in one patient (6.7%). Fourteen patients (93.3%) had favorable functional outcome (modified Rankin score 0–2). ConclusionsTAE for high flow or aggressive intracranial AVFs is a safe and considerable treatment option, especially for those associated with large venous pouches that are challenging and relatively high-risk for TVE.

Clinical and radiological response of aggressive dural arteriovenous fistula after combined glue embolization and hypofractionated helical TomoTherapy

AbstractPurpose:We reported the clinical and radiological outcome of an aggressive dural arteriovenous fistula (DAVF) after combined glue embolization and hypofractionated helical TomoTherapy (Hypo-HT).Materials and methods:Eleven patients whose radiological examinations are consistent with aggressive DAVF were treated with combined glue embolization and Hypo-HT 30–36 Gy in 5–6 fractions. The dosimetric analysis, clinical response and radiological imaging obliteration rate by magnetic resonance angiography or computed tomography angiography were investigated.Results:There were eight males and three females with a male and female ratio of 2·67. The mean age was 51·2 years old (range 37–69). Anatomical imaging sites of disease included transverse-sigmoid sinuses (n = 7), superior sagittal sinus (n = 3) and tentorium cerebelli (n = 1). The mean pitch and MF of treatment plans were 0·273 ± 0·032 and 1·70 ± 0·31, respectively. The average size of PTV were 15·39 ± 7·74 cc whereas the Reff,PTV was 1·50 ± 0·25 cm. The average Dmax and Dmin were 37·52 ± 3·34 and 31·77 ± 2·64 Gy, respectively. HI, CI and CI50 were 0·16 ± 0·06, 1·80 ± 0·56 and 7·85 ± 4·16, respectively. The Reff,Rx and Reff,50%Rx were 1·80 ± 0·24 and 2·90 ± 0·45 cm, respectively. The Reff between 50%Rx and 100%Rx was 1·10 ± 0·28 cm on average. With a mean follow up of 28·5 months (range 9–48), the complete recovery of symptoms was found in 72·7 % (eight patients) within 2–12 months after completion Hypo-HT. Partial recovery was reported in 18·2% (two patients). No clinical response was found in 9·1% (one patient). The total radiographic obliteration rate was 27·3% (three patients), subtotal obliteration was 27·3% (three patients) and partial obliteration was 45·4% (five patients).Conclusions:Satisfactory clinical response of aggressive DAVF was found in all treated patients by combining glue embolization and Hypo-HT. All dosimetric parameters were acceptable. We still need an extended follow up time to assess further radiographic obliteration rate and late side effects of the treatment.

A report of 2 cases of aggressive dural arteriovenous fistula of the transverse-sigmoid sinus presented different clinical course: angiographic and symptomatologic assessment

A report of 2 cases of aggressive dural arteriovenous fistula of the transverse-sigmoid sinus presented different clinical course: angiographic and symptomatologic assessment

Reconsidering an important subclass of high-risk dural arteriovenous fistulas for stereotactic radiosurgery.

Aggressive dural arteriovenous fistulas (dAVFs) with cortical venous drainage (CVD) are known for their relatively high risk of recurrent neurological events or hemorrhage. However, recent natural history literature has indicated that nonaggressive dAVFs with CVD have a significantly lower prospective risk of hemorrhage. These nonaggressive dAVFs are typically diagnosed because of symptomatic headache, pulsatile tinnitus, or ocular symptoms, as in low-risk dAVFs. Therefore, the viability of stereotactic radiosurgery (SRS) as a treatment for this lesion subclass should be investigated. The authors evaluated their institutional experience with SRS for dAVFs with CVD for the period from 1991 to 2016, assessing angiographic outcomes and posttreatment hemorrhage rates. They subsequently pooled their results with those published in the literature and stratified the results based on the mode of clinical presentation. In an institutional cohort of 42 dAVFs with CVD treated using SRS, there were no complications or hemorrhages after treatment in 19 patients with nonaggressive dAVFs, but there was 1 radiation-induced complication and 1 hemorrhage among the 23 patients with aggressive dAVFs. In pooling these cases with 155 additional cases from the literature, the authors found that the hemorrhage rate after SRS was significantly lower among the patients with nonaggressive dAVFs (0% vs 6.8%, p = 0.003). Similarly, the number of radiation-related complications was 0/124 in nonaggressive dAVF cases versus 6/73 in aggressive dAVF cases (p = 0.001). The annual rate of hemorrhage after SRS for aggressive fistulas was 3.0% over 164.5 patient-years, whereas none of the nonaggressive fistulas bled after radiosurgery over 279.4 patient-years of follow-up despite the presence of CVD. Cortical venous drainage is thought to be a significant risk factor in all dAVFs. In the institutional experience described here, SRS proved to be a low-risk strategy associated with a very low risk of subsequent hemorrhage or radiation-related complications in nonaggressive dAVFs with CVD.

Radiosurgery for Dural Arteriovenous Fistulas.

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous connections within the dura, in which meningeal arteries shunt blood directly into the dural sinus or leptomeningeal veins. Among all the treatment options for the treatment of DAVFs, stereotactic radiosurgery (SRS) is a safe and effective modality. SRS provides a minimally invasive therapy for patients who harbor less aggressive DAVFs without cortical vein drainage (CVD), but who suffer from intolerable headache, bruit, or ocular symptoms. For more aggressive DAVFs with CVD associated with immediate risks of hemorrhage, initial treatment with endovascular embolization or surgery for the prompt elimination of the aggressive components of DAVFs is necessary. In such cases, radiosurgery may serve as a secondary treatment for further management of residual nidus after initial intervention. The latent period for the effects of radiation to occur and the longer time for cure compared to surgery and endovascular therapy remains a major drawback for radiosurgery. However, the gradual obliteration of a DAVF after radiosurgery can avoid the immediate risk of aggravated venous hypertension or infarction, which sometimes complicates endovascular embolization and surgery.

Factors Predicting Spontaneous Thrombosis of Aggressive Cranial Dural Arteriovenous Fistulas.

Dural arteriovenous fistula (DAVF) with cortical venous drainage is known to be aggressive in clinical course and is usually managed promptly. Spontaneous resolution of DAVF is a rare phenomenon and usually occurs in benign fistulas. Spontaneous thrombosis of aggressive DAVF is an extremely rare occurrence. The present study aimed to identify the incidence and factors determining spontaneous resolution of aggressive DAVF. All patients presenting to our institution with suspected DAVF during the study period (July 2013 to December 2015) were prospectively enrolled into a database. Different clinical, demographic, and angiographic factors were compared between the control cohort who showed spontaneous resolution and the interventional cohort who underwent endovascular intervention for definite cure. The potential determinants reported in the literature were also included in this detailed analysis. Thirty-two patients were included in the final analysis. Five patients (15.7%) showed spontaneous resolution in the follow-up period while awaiting definitive treatment. Univariate analysis showed 3 variables (DAVF architecture, thrombosis of draining vein, and transit time) to be statistically significant (P < 0.05). However, multivariate logistic regression analysis showed that only sparse fistulous network was significantly associated with acceptable outcome of spontaneous disappearance of DAVF. Spontaneous thrombosis of aggressive DAVF is a known phenomenon in the natural evolution ofcerebral dural arteriovenous malformation. DAVF architecture could categorize this particular subset of DAVF, which had an overall good prognosis. Further observations in large multi-institutional cohorts are needed to validate this finding and to ascertain other factors precipitating this outcome.

Endovascular Treatment of Noncavernous Dural Arteriovenous Fistulas: Analysis of Outcomes with and without Ethylene Vinyl Alcohol

Noncavernous dural arteriovenous fistulas (DAVFs) are uncommon lesions that can be treated from an endovascular approach using various embolic materials. The purpose of this study was to evaluate our outcomes for endovascular treatment of DAVFs with and without the use of ethylene vinyl alcohol (EVOH). We performed a retrospective analysis of 65 patients treated for DAVF at our institution from January 1995 to May 2015. Lesions were classified as aggressive or benign, based on angiography according to Cognard classification. Demographic data, medical comorbidities, presenting symptoms, treatment modality, treatment outcomes, and complications were evaluated for each group. Primary outcome was defined as angiographic occlusion for an aggressive DAVF, and resolution of clinical symptoms for a benign DAVF. The primary outcome was met in 47 (82.5%) of 57 cases with endovascular therapy alone; 23 (69.7%) of 33 aggressive fistulas; and 24 (100.0%) of 24 benign fistulas. There was a 5% overall complication rate. The primary outcome was achieved via endovascular approach in 80.0% (24 of 30) of cases with EVOH, and 85.2% (23 of 27) of cases without EVOH (P = .73). There was a 6% complication rate for procedures using EVOH versus 3% for cases without EVOH (P = 1.00), a 13% clinical recurrence rate for cases using EVOH compared to .0% when EVOH was not used (P = .24), and no angiographic recurrences in either group (P = 1). There were no procedure-related mortalities. Endovascular treatment of DAVFs has a high success rate and low complication rate. Our experience demonstrated no difference in outcomes between lesions treated with EVOH and those treated without EVOH.

The application of susceptibility-weighted MRI in pre-interventional evaluation of intracranial dural arteriovenous fistulas

Background and purposeDetection and characterization of intracranial dural arteriovenous fistula (DAVF) is important to plan appropriate therapeutic management. The aim of this study was to analyze the utility of susceptibility-weighted...

Temporary clamping of bilateral external carotid arteries for surgical excision of a complex dural arteriovenous fistula

Background:Some complex dural arteriovenous fistulas (DAVFs) are lesions that typically have numerous arterial feeders. Surgery, including resection of fistulas or skeletonization of the diseased sinus, is still one of the important treatments for these lesions. However, major blood loss is usually encountered during craniotomy because of abundant arterial feeders from the scalp and transosseous vessels. We present a novel approach for obliteration of the fistulas with less blood loss.Methods:Our first case was a 52-year-old male who suffered from syncope and seizure. Cerebral digital subtraction angiography (DSA) revealed complex DAVFs with numerous arterial feeders from bilateral external carotid arteries (ECAs) and drainage into the superior sagittal sinus with cerebral venous reflux. The second case was a 48-year-old male presenting with chronic headache. His DSA also showed complex DAVFs along the superior sagittal sinus with cerebral venous reflux. In both cases, we performed the surgical procedure to obliterate the pathological fistulas after temporary clamping of bilateral ECAs and noted less blood loss than in the conventional surgery.Results:The follow-up DSA showed successful obliteration of the complex DAVFs on the first case and partial improvement on the second case followed by transarterial embolization (TAE). The symptoms of the both patients were relieved after surgery with good recovery.Conclusion:Temporary clamping of bilateral ECAs can improve the safety and ease the surgical excision for complex DAVFs. By using this technique, neurosurgeons can deal with aggressive DAVFs more confidently and calmly.

Borden-Shucart Type I dural arteriovenous fistulas: clinical course including risk of conversion to higher-grade fistulas

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.

Dural arteriovenous fistulas presenting with brainstem dysfunction: diagnosis and surgical treatment

A cerebral dural arteriovenous fistula (DAVF) is an acquired abnormal arterial-to-venous connection within the leaves of the intracranial dura with a wide range of clinical presentations and natural history. The Cognard classification correlates venous drainage patterns with neurological course, identifying 5 DAVF types with increasing rates of symptomatic presentation. A spinal DAVF occurs when a radicular artery makes a direct anomalous shunt with a radicular vein within the dural leaflets of the nerve root sleeve. A cervical DAVF is a rare entity, as most spinal DAVFs present as thoracolumbar lesions with myelopathy. In this paper the authors present 2 patients presenting initially with brainstem dysfunction rather than myelopathy secondary to craniocervical DAVF. The literature is then reviewed for similar rare aggressive DAVFs at the craniocervical junction presenting with brainstem symptomatology.

Mechanism of the Formation of Dural Arteriovenous Fistula — The Role of the Emissary Vein

Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis.First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. Although EV communicating with dural arteries might play a role as draining routes at first, they start to degrade due to compression of enlarged emissary arteries or to a hemodynamic shift to the drainage pathway of least resistance. Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance. In sinus type DAVF, the sinus is progressively compartmentalized and finally occludes due to thrombogenesis with activated coagulopathy or to hemodynamic hypertrophy of the sinus wall. This progression results in the mature, aggressive DAVF with drainage impairments. Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. Although the etiology of DAVF may be concerned by the thrombo-occlusive change of sinus, the unique theory presented in this report may enable an understanding of the common etiology of both types of DAVF.

Management, risk factors and outcome of cranial dural arteriovenous fistulae: a single-center experience

The role of endovascular interventions in managing dural arteriovenous fistulas (DAVFs) is increasing. Furthermore, in patients with aggressive DAVFs, different surgical interventions are required for complete obliteration or disconnection. Our objective was to evaluate the management of patients with intracranial DAVFs treated in our institution to identify the parameters that may help guide the long-term management of these lesions. The hospital records of 53 patients with intracranial DAVFs were reviewed. We then conducted a systematic telephone interview to obtain long-term follow-up information. The main presenting symptoms were tinnitus and headache. Nineteen (35%) patients presented with intracranial bleeding, 84% of patients scored between 0 and 2 using a modified Rankin Scale at the last follow-up visit. Twenty-four patients were treated surgically. Overall postoperative complications occurred in seven (29%) surgically treated patients, but only two patients permanently worsened. For patients with Borden type II and III fistulas, the annual incidence of hemorrhage was 30%. Two patients had late recurrences of surgically and endovascularly occluded DAVFs. Long-term follow-up showed that compared with spinal DAVFs, only 50% of intracranial DAVFs showed complete remission of symptoms, 41% partial remission, 6% no remission and 4% deterioration of symptoms that led to treatment of the DAVF. In general, intracranial DAVFs can be successfully surgically managed by simple venous disconnection in many cases. However, half of the patients do not show complete remission of symptoms. Age and the occurrence of perioperative complication were the most important determinants of outcome.

AGGRESSIVE INTRACRANIAL DURAL ARTERIOVENOUS FISTULA PRESENTING WITH CEREBROSPINAL FLUID RHINORRHEA

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.

Thrombosis of aggressive dural arteriovenous fistula after incomplete embolization

We report the cases of three patients diagnosed with dural arteriovenous fistula (DAVF) and cortical venous reflux (CVR). All were treated by transarterial endovascular embolization. Residual shunting and cortical venous drainage continued to be present at the end of the treatment procedure, despite the fact that during endovascular embolization glue penetration into the proximal venous component of the fistula had been achieved. Subsequently, follow-up angiography showed total obliteration of the fistulas and absent associated CVR. The fistulas were no longer opacified, and no additional treatment was performed. We demonstrate that residual aggressive DAVF may progress to total thrombosis if strategic deposition of the glue into the venous side has been achieved. Early follow-up angiogram is recommended prior to a planned complementary surgical approach.

Selective disconnection of cortical venous reflux as treatment for cranial dural arteriovenous fistulas.

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.

Benign cranial dural arteriovenous fistulas: outcome of conservative management based on the natural history of the lesion.

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.