Diagnosis of intracranial dural arteriovenous fistulas by carotid duplex sonography

Detection and Differentiation of Dural Arteriovenous Fistulas in the Transverse Sinus/Sigmoid Sinus and Cavernous Sinus Using Carotid Ultrasound: Importance of Evaluation of the Occipital Artery

OBJECTIVES

Dural arteriovenous fistula (DAVFs) in the transverse sinus (TS)/sigmoid sinus (SS) and cavernous sinus (CS) are observed frequently in the clinic. This study aimed to detect DAVFs with ultrasound and compare carotid ultrasound findings between these conditions.

METHODS

We retrospectively reviewed 26 patients with either a TS/SS DAVF or a CS DAVF who were admitted to our hospital for evaluation of DAVFs from 2014 to 2018. The shunt site decision was made by neuroendovascular experts, whereas carotid ultrasound examinations were performed by ultrasound specialists. The flow velocity of the ipsilateral external carotid artery was reviewed in all 26 patients, whereas that of the occipital artery (OA) was examined in 20 patients. Blood flow velocities were compared between the TS/SS DAVF and CS DAVF groups.

RESULTS

The study included 18 patients with a TS/SS DAVF (11 women and 7 men; mean age ± SD, 65.3 ± 18.6 years) and 8 patients with a CS DAVF (7 women and 1 man; mean age, 70.4 ± 9.3 years). Evaluations of feeder arteries on cerebral angiography showed that all patients had dural branches from the internal carotid and middle meningeal arteries as feeders of CS DAVFs, whereas the OA was the major feeder source of all TS/SS DAVF cases. The end-diastolic velocity (EDV) of the external carotid artery was significantly higher in patients with a TS/SS DAVF compared with those with a CS DAVF (P = .004). The EDV of the OA was significantly elevated in TS/SS DAVF cases compared with CS DAVF cases (P < .001).

CONCLUSIONS

Duplex ultrasound parameters are significantly different between patients with TS/SS and CS DAVFs. An increased EDV of the OA can predict the presence of a TS/SS DAVF.

Value of external carotid artery resistive index for diagnosis of cavernous sinus dural arteriovenous fistula and determination of malignant type

PURPOSE

Cavernous sinus dural arteriovenous fistula (CSDAVF) causes hemodynamic disturbance in the arteries, which is detected by carotid Doppler sonography (CDS). The objective of the study was designed for validation of CDS in the diagnosis of CSDAVF.

MATERIAL AND METHODS

42 CSDAVF patients confirmed by angiography were enrolled. All patients were performed CDS before angiography. Evaluations of CDS parameters were compared with control subjects.

RESULTS

The ECA resistive index (RI) shows the best performance. The highest yield shown on left ECA RI and increased from 78.6% to 91.7% on malignant-typed.

CONCLUSION

CDS may be beneficial as the screening tool for CSDAVF.

Diagnostic performance of CT and MRI on the detection of symptomatic intracranial dural arteriovenous fistula: a meta-analysis with indirect comparison

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.

Atypical Feeding and Drainage of Dural AV Fistula

Dural arteriovenous fistulas (DAVF) are frequent causes of pulsatile tinnitus. Color Doppler sonography may play a useful, complementary role to CTA/MRA and digital subtraction angiography (DSA) in the assessment of these anomalies' characteristics, such as an ipsilateral increased flow volume and a low resistive index. In this article, we report a case of DAVF first detected with Color Doppler sonography that displayed an uncharacteristic venous drainage pattern.

Diagnosis and management of intracranial dural arteriovenous fistulas

Dural arteriovenous fistula (DAVF) is a rare type of acquired intracranial vascular malformation. Recent progress in neuroimaging technology, such as advanced MRI and CT, provides non-invasive methods to accurately diagnose DAVF, including evaluation of the hemodynamics of the drainage veins. The clinical manifestations of DAVFs vary widely and depend on the location and venous drainage pattern of arteriovenous shunting. Patients with high grade DAVFs having cortical venous reflux should receive aggressive treatment to prevent the occurrence of intracranial hemorrhage and other neurological deficits related to venous congestion. Intra-arterial or intravenous endovascular embolization remains the primary therapy for high grade DAVF, while open surgery and stereotactic radiosurgery can serve as alternative treatment options. Early and accurate diagnosis with appropriate treatment is the goal for clinical management of DAVFs to reduce symptoms and prevent the development of venous congestion and stroke.

Validity of Carotid Duplex Sonography in Screening for Intracranial Dural Arteriovenous Fistula among Patients with Pulsatile Tinnitus

Pulsatile tinnitus may result from intracranial dural arteriovenous fistula (DAVF), which requires early diagnosis and management. This study validated the role of carotid duplex sonography in screening for DAVF in patients with pulsatile tinnitus. The criteria used for DAVF screening were low resistance index of the external carotid artery or occipital artery (OA). Patients then underwent head magnetic resonance imaging to confirm the diagnosis. Of the 155 patients with pulsatile tinnitus who were prospectively screened, 25 (16.1%) had a low resistance index in either the external carotid artery or occipital artery. All were proven to have DAVF. The diagnostic sensitivity, specificity, positive predictive value and negative predictive value were 96%, 100%, 100% and 98%, respectively. Thus, carotid duplex sonography focusing on low resistance indexes of the external carotid and occipital arteries may be a valuable tool in screening for DAVF in patients with pulsatile tinnitus.

The role of the occipital artery in the diagnosis of intracranial dural arteriovenous fistula using duplex sonography

BACKGROUND AND PURPOSE

The occipital artery is usually a main feeding artery of an intracranial dural arteriovenous fistula. The aim of this study was to establish the role of the OA in the diagnosis of DAVFs by using duplex sonography.

MATERIALS AND METHODS

We first compared the clinical features between patients with DAVFs having and not having the OA as one of feeding arteries in 181 consecutive patients with DAVFs. Second, we investigated the OA by using duplex sonography in 60 control subjects to test the accessibility. Finally, we studied 24 DAVF and 60 non-DAVF patients to validate the diagnostic performances of duplex sonography. Hemodynamic parameters, including the resistance index and flow velocity, were analyzed.

RESULTS

Half of the DAVFs (51%) had the OA as one of feeding arteries. DAVFs with the OA as one of the feeders were more likely located at noncavernous sinuses; to belong to types IIb, IIa+b, III, IV, or V; and to be associated with aggressive manifestations compared with DAVFs without the OA as a feeder (P < .05). Accessibility of the OA by using duplex sonography was 100%. The resistance index was lower and flow velocity was higher in the OA among patients with DAVFs compared with control subjects (P < .001). An OA resistance index <0.76 yielded a sensitivity and specificity of 96% and 97%, respectively, for the diagnosis of a DAVF.

CONCLUSIONS

The OA resistance index can be used to screen for DAVFs having the OA as one of feeding arteries, and this kind of DAVF was usually associated with nonbenign clinical courses.

Selective Occipital Artery Sonography for Dural Arteriovenous Fistulas

Carotid duplex sonography is a useful method for evaluation of dural arteriovenous fistulas. The resistance index of the external carotid artery has been reported to correlate with the efficacy of treatment and recurrence or aggravation of dural arteriovenous fistulas. Herein, we describe a case of dural arteriovenous fistulas mainly supplied by the occipital artery and show that the resistance index of the occipital artery was more sensitive than that of the external carotid artery. To the best of our knowledge, this is the first report to describe the feasibility of occipital artery detection by carotid duplex sonography and clinical application of the resistance index of the occipital artery for dural arteriovenous fistulas.

Pulsatile tinnitus in a case of traumatic temporal extradural arteriovenous fistula: carotid duplex sonography findings before and after embolization

Carotid duplex sonography (CDS) is regarded as a screening tool for lateral dural arteriovenous fistulae (AVF). However, data on evaluating long-term effects of endovascular treatment are limited. We report the CDS findings in the feeding arteries of a traumatic temporal extradural AVF before and after transarterial embolization. Volume flow of the left common carotid artery was greater than the right (433 ml/minute versus 294 ml/minute right) and the resistance index of the left external carotid artery was lower than the right (0.69 left versus 0.84 right). Both parameters returned to normal 4 months after embolization, thus confirming successful endovascular treatment.

Assessment of Dural Arteriovenous Fistulae by Transcranial Color-Coded Duplex Sonography

Background and Purpose— To study hemodynamic changes and to determine the value of contrast-enhanced transcranial color-coded sonography (TCCS) for the evaluation of dural arteriovenous fistulae (DAVF) before and after transcatheter embolization.

Methods— Twenty-four patients (mean age 61±11 years) with occipitally located DAVF were studied with contrast-enhanced TCCS using the transtemporal bone window in transverse-axial and coronal insonation planes. Blood flow velocity measurements of all depictable basal cerebral veins and sinuses were obtained before and after transcatheter embolization. Pretreatment and post-treatment flow velocity values were compared. Results of digital subtraction angiography (DSA) were compared with sonographic findings.

Results— Four of the 24 patients (17%) could not be studied because of an insufficient temporal bone window. In all remaining patients (n=20), draining veins/sinuses could be identified because of pathologically increased blood flow velocities with peak systolic flow velocities of >50 cm/s. Of the 27 draining vessels depicted by DSA, TCCS correctly identified 25 (93%): the basal vein (3 of 3), the straight sinus (3 of 3), the superior sagittal sinus (1 of 3), the transverse sinus (9), the sigmoid sinus (4), and the superior petrosal sinus (5/5). However, TCCS failed to depict supplementary drainage via cortical veins. After transcatheter embolization, mean reduction of blood flow velocity was 44±18% ( P <0.01) compared with pretreatment values.

Conclusions— Contrast-enhanced TCCS is a promising technique for monitoring embolization of DAVF, follow-up after complete fistula occlusion, and may even be useful as a screening tool in patients with pulsatile tinnitus.