MR imaging of dural AV fistulas at the cavernous sinus

The magnetic resonance appearance of dural arteriovenous fistulas (AVFs) at the cavernous sinus (CS) was studied in six angiographically verified cases. Magnetic resonance clearly demonstrated shunted blood as an area of signal void both in the CS and in the superior ophthalmic vein. The relationship between shunted blood, internal carotid artery, and extraocular nerves, as well as proptosis, enlargement of the extraocular muscles, and bulging of the lateral wall of the CS were also depicted in the images. Normal venous flow in the involved CS was shown as a low signal area that enhanced after gadolinium administration. Magnetic resonance is useful for screening and follow-up examinations of dural AVFs at the CS. It is essentially a noninvasive procedure that may be repeated and obviates the need for follow-up angiography. However, it should be noted that a signal void in the CS sometimes represents normal venous flow. A definite diagnosis should rely on angiography, which is essential for therapeutic planning.     

Transorbital puncture for the treatment of cavernous sinus dural arteriovenous fistulas

This report describes a series of patients for whom dural arteriovenous fistulae (DAVFs) of the cavernous sinus were successfully embolized using a percutaneous, transorbital technique to directly cannulate the cavernous sinus. A vascular access needle and catheter are percutaneously advanced along the inferolateral aspect of the orbit to access the cavernous sinus via the superior orbital fissure. Safe and effective embolization is achieved without the need for a surgical cut-down.     

Basal cerebral venous drainage from cavernous sinus dural arteriovenous fistulas

Introduction  This study aimed to define the patterns of basal cerebral venous drainage (BCVD) from cavernous sinus dural arteriovenous fistulas (CSDAVFs). Materials and methods  Forty sets of selective angiographic data from 36 patients with spontaneous CSDAVFs (age range, 53–79 years) were retrospectively analyzed for their drainage patterns. Three types of BCVD were observed, i.e., superolateral type, BCVD via the deep middle cerebral vein or uncal vein; posterolateral type, BCVD via the superior petrosal sinus and petrosal vein; and posteromedial type, BCVD via the bridging vein and the anterior pontomesencephalic vein. MR images and/or 3D-DSA images were also reviewed when available. Results  BCVD from CSDAVF was found in 12 patients (30%), and the other drainage routes included the superior ophthalmic vein in 25 (63%), the inferior petrosal sinus in 17 (43%), the superficial middle cerebral vein in 17 (43%), intercavernous sinus in 15 (38%), the superior petrosal sinus in seven (18%), and pterygoid plexus in two (5%), respectively. In 12 patients with BCVD, superolateral type was found in four (33%), posterolateral type in five (42%), and posteromedial type in seven (58%). Four cases of posteromedial type were associated with other types of BCVD. Conclusion  CSDAVFs are often associated with BCVD via three different pathways. The posteromedial type via the bridging vein is the most frequent type of BCVD.     

Recovery of opthalmoplegia associated with cavernous sinus dural arteriovenous fistulas after transvenous cavernous sinus packing

Background

We report the recovery of ophthalmoplegia in 11 patients with cavernous sinus dural arteriovenous fistula (CSDAVF) after sinus packing at follow-up.

Methods

Of 18 patients with CSDAVF treated with transvenous cavernous sinus packing between August 2002 and December 2007 at Beijing Tiantan Hospital, there were 9 patients with initial CNIII or CNVI dysfunction and 2 patients with CNVI dysfunction immediately after cavernous sinus packing selected and reevaluated.

Results

Of 11 patients with CNIII or CNVI palsy, recovery was complete in 10. In 1 patient, complete CNVI palsy was unchanged because the CSDAVF was not cured. There were 6 men and 5 women with a mean age of 52.9 years. In 5 patients, CNVI palsy was associated with chemosis, proptosis and pulsatile tinnitus. Timing of treatment after onset of symptoms was from 4 to 35 days in 9 patients. All CSDAVFs were Barrow type D. Mean follow-up after treatment was 17.7 months (range, 2-54 months).

Conclusion

CSDAVF-induced CNIII or CNVI palsies can be cured after cavernous sinus packing transvenously in most patients.     

Assessment of dural arteriovenous fistulas of the cavernous sinuses on 3D dynamic MR angiography

BACKGROUND AND PURPOSE: Flow voids within the cavernous sinuses and/or certain venous drainage on spin-echo MR imaging and time-of-flight (TOF) flow enhancement on MR angiography (MRA) have indicated high-velocity shunt flow and have been used for screening patients with dural arteriovenous fistulas (DAVFs) of the cavernous sinuses. In this investigation, the capabilities of 3D dynamic MRA as a flow-independent approach and those of conventional MR imaging techniques were compared with selective angiography for the diagnosis of DAVFs of the cavernous sinuses.MATERIALS AND METHODS: This retrospective study involved 18 patients with angiographically proved DAVFs of the cavernous sinuses and 12 control subjects. Sixteen partially overlapping sequential MR images were acquired on contrast-enhanced 3D dynamic MRA between the petrosal bone and the orbital roof. Two experienced observers blinded to the clinical data and results of angiography independently graded 3D dynamic MRA, fast spin-echo T2-weighted imaging (FSE T2WI), and TOF MRA.RESULTS: The average area under the receiver operating characteristic curve values and interobserver κ scores for the diagnosis of DAVFs on 3D dynamic MRA, FSE T2WI, and TOF MRA were 0.99, 0.89, and 0.95; and 0.92, 0.71, and 0.73, respectively. Those for the diagnosis of anterior, posterior, and retrograde cortical venous drainage on 3D dynamic MRA were 0.72, 0.95, and 0.81; and 0.56, 0.50, and 0.49, respectively.CONCLUSION: In this small series, screening 3D dynamic MRA directly demonstrates DAVFs of the cavernous sinuses and has improved diagnostic capability.

In patients with the classic triad of pulsating exophthalmos, orbital bruit, and conjunctival chemosis, the clinical diagnosis of arteriovenous fistulas (AVFs) of the cavernous sinuses is not difficult, and cerebral angiography is performed for definitive diagnosis. However, dural AVFs (DAVFs) without anterior drainage may not cause typical congestive orbito-ocular features, and thrombosis of the draining veins may lead to spontaneous resolution of the disorder.^1–6 Therefore, it is desirable to perform less invasive diagnostic examinations before conventional angiography. So far, flow voids within the cavernous sinuses and/or inferior petrosal sinuses on spin-echo MR images followed by time of flight (TOF) flow enhancement on source images of MR angiography (MRA) have been indicative of AVF.^7–10 Although these are safe and practical methods, dependence on flow velocity sometimes makes it impossible to distinguish fast normal flow from abnormal shunt flow or slow abnormal shunt flow from normal flow.^9–13The recent advancement of MR imaging technology has allowed first-pass contrast-enhanced dynamic MRA and 2D MR digital subtraction angiography to be applied to cerebral arteriovenous malformations (AVMs) or DAVFs.^14–18 In addition, although the conventional use of 3D dynamic MRA for their diagnosis has been difficult due to the limitation of low temporal resolution, its application has been described in recently published articles.^19,20 However, until now, there has not been a comparative study of dynamic MRA and conventional MR imaging for the diagnosis of DAVFs of the cavernous sinuses.According to a study of dynamic CT of the cavernous sinuses²¹ and physiologic studies on the cerebral circulation time,^22,23 it was hypothesized that imaging temporal resolution under several seconds would demonstrate DAVFs of the cavernous sinuses on dynamic MRA. Therefore, we used the 3D data-acquisition technique, a standard pulse sequence, and postulated that early enhancement of the cavernous sinuses was a main direct feature of the shunts. This methodology will improve the diagnostic capability for screening of DAVFs of the cavernous sinuses.     

Diffuse dural enhancement in cavernous sinus dural arteriovenous fistula

We describe unusually extensive contrast enhancement of the dura mater on MRI in a case of dural arteriovenous fistula of the cavernous sinus.     

Transvenous embolization of dural fistulas involving the cavernous sinus

Because of the risks associated with arterial embolization of cavernous dural fistulas, we have sought an alternative method to promote fistula closure. Thirteen patients underwent transvenous embolization as a treatment for symptomatic cavernous dural fistulas. All procedures were performed from a femoral vein access through the inferior petrosal sinus or basilar plexus. In five patients the inferior petrosal sinus was not angiographically demonstrable; however, embolization was still possible through this route in two patients. The embolic agents used were detachable balloons in one patient, coils alone in five, coils and liquid adhesives in four, coils plus silk sutures in one, silk sutures alone in one, and liquid adhesives alone in one. Nine patients had follow-up angiograms, which showed complete obliteration of the fistulas and complete resolution of related symptoms. One patient had complete resolution of clinical symptoms but refused follow-up angiography. Another patient had 50% decrease in fistula flow on the follow-up angiogram and improvement in clinical symptoms. Two patients had complete fistula obliteration after embolization and progressive improvement in symptoms but follow-up angiograms had not been obtained. Follow-ups ranged from 1 to 97 months (mean, 15 months). Two complications were related to this treatment. An embolic stroke followed transient placement of a balloon in the internal carotid in one patient, and a second patient developed transient visual loss when the venous outflow pathways were occluded before fistula closure. The fistula was immediately closed with complete recovery of vision. With recent advances in microcatheter and embolic agent technology, transvenous closure of cavernous dural fistulas is now possible.(ABSTRACT TRUNCATED AT 250 WORDS)     

Radiotherapy of dural arteriovenous malformation in the cavernous sinus

Six patients with dural arteriovenous malformation (DAVM) in the cavernous sinus were treated by irradiation. The region of the abnormal vascular network was irradiated with a 10 MV linear accelerator; the total dose given ranged from 3,200 to 5,100 cGy (150-200 cGy per day, 750-1,000 cGy per week). All patients responded favorably to the treatment, with three of the six having no residual symptoms or signs of disease. Postradiotherapy angiography confirmed the complete disappearance of the shunts in two of the three patients. No significant side effects were observed during the follow-up period, which ranged from 10 months to four years. Radiotherapy is considered to be a useful treatment method for DAVM, especially for those patients having shunts from the meningeal branches of the internal carotid artery.     

MR imaging findings of intracranial dural arteriovenous fistulas: relations with venous drainage patterns

BACKGROUND AND PURPOSE: Venous drainage patterns are a major determinant of clinical outcome in intracranial dural arteriovenous fistula (DAVF) patients. In this study, we sought to identify MR imaging finding differences between DAVF types classified on the basis of venous drainage patterns. METHODS: Twenty-seven patients diagnosed as having DAVFs by conventional angiography were included. Medical records (n = 27), and MR imaging (n = 27) and MR angiography (MRA; n = 11) findings were retrospectively reviewed. MR imaging findings included flow void cluster, engorged ophthalmic vein/proptosis, white matter hyperintensity, intracranial hemorrhage, dilated leptomeningeal or medullary vessels, venous pouch, and leptomeningeal or medullary vascular enhancements. MRA findings included identifiable fistula, venous flow-related enhancement, and prominent extracranial vessels. Patients' presentations and MR imaging findings were compared among angiographic type I, II, and III cases (according to Borden's classification), and MRA findings were compared between cases with and without retrograde leptomeningeal venous drainage (RLVD). RESULTS: Patient presentations were aggressive in one (13%) of the type I cases, 5 (50%) of the type II cases, and 8 (100%) of the type III cases (P = .002). Aggressive presentations included hemorrhage, focal neurologic deficits, seizures, intracranial hypertension, and an altered mental status. MR images showed significantly higher frequencies of dilated leptomeningeal or medullary vessels in a higher type [0 in type I, 5 (42%) in type II, and 7 (100%) in type III], and of leptomeningeal or medullary vascular enhancements [0 in type I, 4 (33%) in type II, and 7 (100%) in type III]. By using MRA, fistulas were identified only in cases with RLVD (5 [83%]). Venous flow-related enhancement was present in 10 cases (91%). A sole false-negative case on MRA, as compared with conventional angiography, resulted from nonvisualization of the slow venous flow (8%). No false-positive fistula was found at the other intracranial sites in all cases. Overall, MRA assessment for DAVF was adequate for both fistula and venous flow-related enhancement in 10 cases (91%) and inadequate in a remaining case because of the fistular location out of field. CONCLUSION: MR imaging demonstration of leptomeningeal or medullary vascular dilation and enhancements may be associated with features that are considered predictors of a poor outcome and indicates a need for urgent therapy in intracranial dural AVF patients. MRA is a complementary tool for the identification of dural AVF with venous flow-related enhancement.     

Onyx结合弹簧圈岩下窦入路栓塞海绵窦区硬脑膜动静脉瘘

目的：探讨应用Onyx结合弹簧圈岩下窦入路栓塞海绵窦区硬脑膜动静脉瘘（csDAVF）的优势及疗效。方法：对6例csDAVF患者应用Onyx结合弹簧圈岩下窦入路栓塞,并评价疗效。结果：6例采用＂股静脉-岩下窦＂入路成功栓塞csDAVF,4例csDAVF瘘口完全闭塞,出院时症状消失;2例csDAVF次全闭塞,出院时症状改善,随访1-2个月临床症状消失。全部病例随访1-12个月,未见症状复发。结论：经＂股静脉-岩下窦＂途径,较易到达病变部位;海绵窦为闭塞csDAVF瘘口的理想部位,Onyx能在海绵窦中形成良好弥散,结合弹簧圈的应用有利于瘘口的闭塞。     

Anatomical variations in termination of the uncal vein and its clinical implications in cavernous sinus dural arteriovenous fistulas

Introduction

The aim of the study was to investigate the variations in the uncal vein (UV) termination and its clinical implication in cavernous sinus dural arteriovenous fistulas (CSDAVFs).

Methods

Biplane cerebral angiography in 80 patients (160 sides) with normal cerebral venous return (normal group) was reviewed with special interest in the termination of the UV. Frequency and types of uncal venous drainage from CSDAVFs in consecutive 26 patients were also analyzed.

Results

In the normal group, the UV was identified in 118 sides (74 %). The UV terminated into cavernous sinus (CS) in 41 sides (34 %), the superficial middle cerebral vein (SMCV) in 58 sides (48 %), the laterocavernous sinus (LCS) in 15 sides (13 %), and the paracavernous sinus (PCS) in 4 sides (3 %). Cerebral venous blood via the UV draining into the CS directly (n?=?41) or through the SMCV and/or the LCS (n?=?45) was observed in 86 sides (54 %). Uncal venous drainage from CSDAVFs was found in 13 patients (50 %). The CSDAVFs drained directly into the UV in two patients, drained via LCS into the UV in two patients, and drained through the SMCV into the UV in the remaining nine patients. All cases were successfully treated by transvenous embolization with special attention given to uncal venous drainage.

Conclusion

There are several variations in UV termination according to the embryological development of the primitive tentorial sinus and the deep telencephalic vein. Careful attention should be paid to uncal venous drainage for the treatment of CSDAVFs.     

Bilateral dural arteriovenous fistula in the region of the cavernous sinus

Summary The case of a patient with a fistula between the left internal carotid artery and the cavernous sinus, and another fistula between the right external carotid artery and the cavernous sinus, is reported. The clinical symptomatology, which was of spontaneous onset, was unilateral and consisted of exophthalmos and injection of the conjunctiva on the left side. Almost complete remission occurred after angiography.     

Usefulness of source images from three-dimensional time-of-flight MR angiography after treatment of cavernous dural arteriovenous fistulas

PURPOSE: Source images from three-dimensional time-of-flight MR angiography (3D TOF MRA) are useful for the diagnosis of cavernous dural arteriovenous fistulas. The purpose of this study was to assess the accuracy of source images from 3D TOF MRA compared with digital subtraction angiography (DSA) as a follow-up technique for the detection of residual or recurrent fistulas after treatment. We also assessed the effect of embolized materials in the evaluation of MRA. MATERIALS AND METHODS: In 14 patients who were treated with embolization and/or radiation therapy, follow-up MRA and DSA were performed after a mean follow-up duration of 3 months. Two observers independently reviewed the source images from MRA in regard to the presence of hyperintense regions within the cavernous sinus and enlargement of the draining veins. They also assessed whether embolized materials affected the evaluation. RESULTS: Sensitivity, specificity, and positive predictive value of source images from MRA in revealing residual or recurrent fistulas were 100% (9 of 9 true positive findings), 80% (4 of 5 true negative findings), and 90% (9 of 10 positive findings), respectively. In all five patients treated with platinum coils, hypointense areas in the cavernous sinus were observed but did not affect image evaluation. CONCLUSION: Source images from 3D TOF MRA provided accurate diagnosis with no effect of embolized materials in the follow-up of treated cavernous dural arteriovenous fistulas.     

Marginal sinus arteriovenous fistulas mimicking carotid cavernous fistulas: diagnostic and therapeutic considerations

Marginal sinus fistulas (MSFs) are uncommon vascular anomalies. Occasionally, the dominant venous drainage is forced retrograde up the inferior petrosal sinus and into the cavernous sinus, causing chemosis, proptosis, and ocular hypertension, mimicking a carotid cavernous fistula. This atypical clinical presentation may lead to misdiagnosis and inappropriate hazardous treatment of an MSF. Identifying the site of the fistula and understanding the anatomy of the venous drainage are critical in providing appropriate, safe, and efficacious endovascular treatment.     

Gadolinium-DTPA enhanced MR imaging of spinal dural arteriovenous fistulas

To evaluate the role of magnetic resonance (MR) in the diagnosis of dural arteriovenous (AV) fistulas and the resulting myelopathy, the MR examinations of 11 patients with symptoms and signs of slowly progressive myelopathy of the lower spinal cord have been reviewed. Patients with intradural or extradural AV malformations were excluded. Six patients have been examined without the use of a contrast agent. The other five patients were studied prior and after intravenous administration of gadolinium-diethylenetriamine pentaacetic acid (DTPA). Serpentine linear areas of low signal due to flow void effects within the subdural space have been detected in seven patients. The T1-weighted sagittal images and T2-weighted sagittal and axial images demonstrated signal intensity changes within the center of the cord due to prolongation of T1 and T2 relaxation times. In addition, a relatively abrupt increase of the sagittal and transverse diameters of the lower thoracic cord was found in all cases. In nine patients T1-weighted, proton-density and T2-weighted sagittal images presented "blurred" margins of the lower thoracic cord. After intravenous administration of Gd-DTPA (0.1 mmol/kg), contrast enhancement was present not only within these vessels but also within the lower spinal cord. There was only slight enhancement of the cord immediately after injection of the contrast agent, but significant enhancement was observed 40-45 min later.     

Characteristic MR imaging findings of cavernous hemangiomas in the cavernous sinus

Cavernous hemangiomas occur very rarely in the cavernous sinus and are difficult to diagnose preoperatively. MR images obtained in five patients with surgically verified cavernous hemangiomas in the cavernous sinus were reviewed. MR images showed hypointensity on T1-weighted images and well-defined hyperintensity on T2-weighted images with marked homogeneous enhancement after contrast material administration. We report the characteristic MR imaging observations for these lesions.     

Transarterial Onyx packing of the transverse-sigmoid sinus for dural arteriovenous fistulas

Objective

To report transarterial Onyx packing of the transverse–sigmoid sinus for dural arteriovenous fistulae (DAVFs).

Methods

We retrospectively studied consecutive 5 patients (2 female and 3 male) treated for a transverse–sigmoid sinus DAVF since 2008 in whom transverse sinus packing was attempted with a transarterial approach Onyx embolization. The mean clinical follow-up period was 6.2 months.

Results

Of the five lesions, 2 fistulas were type IIa, 3 were type IIb, according to the Cognard classification. Five Onyx embolizations were all performed via the middle meningeal artery. Cure was obtained in all cases after completion of direct sinus packing. No complications were revealed.

Conclusions

Transarterial Onyx packing of transverse–sigmoid sinus for DAVFs via the meningeal arterial system is a safe therapeutic alternative in selected cases.