Endovascular occlusion of high-flow intracranial arteriovenous shunts: technical note

Endovascular closure of high-flow arteriovenous (AV) shunts in intracranial AV malformations or pial fistulas is technically challenging. In this paper, we illustrate two simple methods to occlude large high-flow AV shunts in a controlled manner.     

Association of distinct intracranial pial and dural arteriovenous shunts

Intracranial pial and dural arteriovenous shunts may exist at different sites in the same patient. The etiology, natural history and treatment of these associated conditions have not been completely determined. We reviewed the records of 765 cases of pial arteriovenous malformation and 137 dural arteriovenous fistulae and malformations. We selected eight patients with both pial and dural arteriovenous shunts, separate anatomically, with distinct feeding arteries and draining veins, representing 1 % of pial and 17 % of dural shunts. Presentation was related to the dural lesion in 5 cases (62.5 %) and to the pial malformation in three (37.5 %). Treatment of these lesions should be considered separately based on their angioarchitecture and natural history. Received: 9 January 2001/Accepted: 10 January 2001     

Transarterial balloon-assisted glue embolization of high-flow arteriovenous fistulas

Introduction We report here our experience in treating high-flow arteriovenous fistulas (AVFs) of the brain and spine using balloon-assisted glue injection. Methods During a 3-year period (2003–2005) five patients with high-flow AVFs were treated at our hospital using transarterial balloon-assisted glue injection. There were two pial AVFs, one dural AVF, one vein of Galen malformation and one perimedullary AVF of the cervical spine. All patients were clinically followed-up for 12–48 months. Results Immediate angiographic obliteration was achieved in all patients. The fistulas remained closed in all patients, as ascertained by follow up-angiograms. No new neurological deficits related to the procedure were detected. Clinically, one patient with severe pre-treatment neurological deficit experienced excellent recovery. Conclusion Transarterial balloon-assisted glue embolization of high-flow AVFs is a feasible and efficient treatment. This technique affords more control in the glue injection and minimizes the risk of distal embolization.     

Embolization of dural arteriovenous fistulas with interlocking detachable coils.

Our clinical experience with interlocking detachable coils for the embolization of high-flow dural arteriovenous fistulas is reported. Interlocking detachable coils are useful for transarterial and transvenous embolizations of dural arteriovenous fistulas because (a) immediate coil detachment is possible, (b) the coils can be replaced easily, (c) detached coils rarely migrate, and (d) fewer interlocking detachable coils than conventional fiber coils are required for successful embolization.     

The use of electrolytically detachable coils in treating high-flow arteriovenous fistulas.

BACKGROUND AND PURPOSEHigh-flow arteriovenous fistulas (AVFs) are commonly treated by using an endovascular approach with a variety of materials. The use of a Guglielmi electrolytically detachable coil (GDC) provides the ability to reposition or remove the coil if its position is not optimal and may minimize the risk of coil migration or distal embolization. This study reports our experience in using these coils alone or in combination with other materials in the treatment of intracranial and cervical high-flow fistulas.METHODSTwelve patients with AVFs were treated with GDCs via the transvenous or transarterial-transfistulous routes. The six dural AVFs treated transvenously were also treated transarterially, and the GDCs were combined with fibered coils in three of these patients and in two other patients with pial AVFs. All patients have been clinically followed up for 12 to 48 months (mean, 28 months).RESULTSAngiographic obliteration was obtained in all 12 patients. The fistulas have remained closed in 11 patients, as ascertained by angiographic confirmation in two patients and by clinical examination in nine patients. The one patient with recurrence experienced neurologic improvement and refused further treatment. GDCs required repositioning before detachment in seven patients, and no migration occurred after detachment.CONCLUSIONGDCs are useful for the treatment of high-flow AVFs. They afford more control in the placement of coils and may provide an anchoring point for more thrombogenic materials.     

Two cases of dural arteriovenous malformation occurring after intracranial surgery

Summary The occurrence of post-operative dural arteriovenous malformation (AVM) has rarely been proved angiographically. The authors report two such cases: in one, a pure dural AVM was located in the region of the cavernous sinus and in another a mixed pial and dural AVM was found in the posterior fossa. The literature about pathogenesis is reviewed.     

Multiple dural arteriovenous fistulas of the cranium and spine

Dural arteriovenous fistulas are acquired lesions that usually involve the dura around the cavernous sinus. The transverse, sigmoid, and superior sagittal sinuses may be affected occasionally. With the exception of bilateral cavernous sinus dural arteriovenous fistulas, the simultaneous occurrence of dural arteriovenous fistulas at two locations is rare. Among 105 patients evaluated for dural arteriovenous fistulas, we identified seven patients with fistulas at two sites. The age of the patients ranged from 27 to 74 years. Presentation was related to hemorrhage in three patients, loss of vision in four, and a bruit and headaches in one. Patients were treated with combined surgical and endovascular techniques. All treated lesions were completely closed with no mortality or permanent morbidity. The presence of multiple fistulas must be considered in patients being evaluated for dural arteriovenous fistulas. Patients with multiple fistulas usually present with life-threatening hemorrhages or acute neurologic decline; the risk factor for hemorrhages, including those related to venous outflow obstruction, is high in patients with multiple dural arteriovenous fistulas.     

Spontaneous resolution of low-flow spinal arteriovenous fistulas

Purpose

Spinal vascular anomalies with arteriovenous blood shunting include spinal arteriovenous malformations (SAVMs) and spinal arteriovenous fistulas (SAVFs), which are distinguished by the presence or absence of an interposed nidus. SAVFs can be further characterized based on their location (perimedullary, dural, or extradural) and flow pattern (high-flow versus low-flow shunts). The spontaneous resolution of a spinal vascular malformation, i.e., the complete disappearance—in the absence of therapeutic measures—of a lesion previously identified by angiography, seems to represent an exceptional phenomenon.

Methods

This study retrospectively analyzed seven patients with spontaneously resolving spinal vascular malformations observed by the senior author between January 2008 and April 2017.

Results

A total of 143 spinal vascular malformations were angiographically evaluated during the considered time period, including nine spontaneously resolving SAVFs in six patients, seven spinal epidural fistulas, and two spinal dural arteriovenous fistula.

Conclusion

The “spontaneous” resolution of spinal vascular malformations appears to selectively involve SAVFs. While vessel wall alterations previously documented on the venous side of SAVFs may play an important role in the regression of these lesions, angiography seems to represent a significant contributing factor, probably through the prothrombotic properties of nonionic contrast agents.

     

Paraspinal arteriovenous shunts in children

Arteriovenous shunts within the spinal canal and in the paraspinal region are unusual. Spinal cord and dural arteriovenous communications have been the subject of numerous reports but paraspinal shunts causing venous congestion in the spinal canal are rarer and may present special problems in diagnosis and management. We describe three children with paraspinal arteriovenous malformation, associated with overt or potential venous congestion in the spinal canal. In each case, the lesion was successfully obliterated by endovascular therapy. Embolisation with permanent occlusive agents is an effective treatment for these rare but potentially debilitating lesions.     

Dural arteriovenous fistula associated with neoplastic dural sinus thrombosis: two cases

Intracranial dural arteriovenous fistulae are direct arteriovenous shunts within the dura matter. We report two cases of arteriovenous fistulae upstream to a neoplastic dural sinus thrombosis. These cases add further support to the acquired etiology of dural arteriovenous fistulae and to the fact that venous hypertension is one of the most important precipitating factors. Received: 9 January 2001/Accepted: 10 January 2001     

Treatment of traumatic cervical arteriovenous fistulas with N-butyl-2-cyanoacrylate

We report 2 cases of traumatic arteriovenous fistulas in the neck treated with transarterial embolization with n-butyl-2-cyanoacrylate (n-BCA). In both cases, covered stent placement across the fistula to preserve the artery was not possible. Detachable coil placement was attempted in one case but was not successful. Both fistulas were successfully treated with n-BCA embolization. To our knowledge, these are the first 2 such cases reported of high-flow cervical arteriovenous fistulas treated with n-BCA embolization.     

Double spinal dural arteriovenous fistulas

We present a patient with double spinal dural arteriovenous fistulas revealed by progressive myelopathy. Numerous dilated veins extending along the entire length of the spinal cord were found on MR imaging. Angiography showed a first spinal dural fistula at the level of T7 with descending venous drainage and a second spinal dural fistula at the level of T5 with ascending venous drainage. Both fistulas were cured by therapeutic embolization.     

Follow-up MRI in dural arteriovenous malformations involving the cavernous sinus: emphasis on detection of venous thrombosis

Summary Six patients with a dural arteriovenous malformation (dural AVM) involving the cavernous sinus were followed up with magnetic resonance imaging in order to assess change in the lesions. Spin-echo (SE) imaging of three patients in whom the AVM appeared to have closed at least 1 month earlier (two of them spontaneously, and one after external carotid artery embolization) showed neither apparent flow void in the involved cavernous sinus nor evidence of venous thrombosis. SE images of the other three patients who had not been cured by external carotid artery embolization (two of whom were examined within a week of treatment), detected persisting arteriovenous shunts, including high-flow cortical venous drainage, seen as flow void. Two-dimensional time-of-flight MR angiography (2D TOF MRA) was performed simultaneously in three patients. Whereas shunting blood and the normal cavernous sinus were of high intensity, presumed thrombosed cavernous sinuses were isointense with stationary brain tissue. SE imaging can confirm the resolution of arteriovenous shunts, but poorly delineates ver acute and chronic thrombosis of the draining veins. In contrast, 2D TOF MRA directly demonstrates flowing blood, permitting the diagnosis of venous thrombosis; it should be included in follow-up of a dural AVM involving the cavernous sinus when venous thrombosis is suspected.     

Diagnosis and therapy of dural arteriovenous fistulas

Intradural arteriovenous fistulas can occur at any location within the dura mater. Patients can be clinically asymptomatic or show symptoms ranging from mild up to fatal hemorrhaging. Previously dural arteriovenous fistulas were often dealt with surgically via a variety of access routes. Since recent years there is now the possibility to close most dural arteriovenous fistulas by endovascular embolisation. In addition, stereotactic radiation therapy is available, which can also achieve good results especially in combination with surgery.     

Prenatal diagnosis of intracranial pial arteriovenous fistula and endovascular treatment during the neonatal period

We present a case with prenatal diagnosis of an intracranial high-flow pial arteriovenous fistula that was draining into the vein of Galen in the third trimester of pregnancy. The child was treated by transcatheter embolization with N-butyl 2-cyanoacrylate (NBCA) via the umbilical artery in the early neonatal period due to intractable cardiac failure. Hydrocephalus developed and a ventriculoperitoneal shunt was placed. At the time this report was prepared, the patient was 20 months old and without cardiac failure, but with a delay in neurological development. Prenatal diagnosis and endovascular treatment in the early neonatal period is important in preventing heart failure and resultant mortality due to such high-flow vascular malformations. To the best of our knowledge, the combination of prenatal diagnosis of an intracranial high-flow pial arteriovenous fistula draining into the vein of Galen and endovascular treatment in the early neonatal period is presented here for the first time.     

Improved distal distribution of n-butyl cyanoacrylate glue by simultaneous injection of dextrose 5% through the guiding catheter: technical note

Introduction The use of n-butyl cyanoacrylate (NBCA) as an adhesive agent for embolization of high-flow intracranial and extracranial vascular lesions is well established. To be successful, the embolization of arteriovenous malformations and fistulas must achieve obliteration of the arteriovenous shunts themselves rather than simply occlude the feeders proximal to the lesion. However, the feeders cannot always be negotiated over their entire length. This is often the case with dural arteriovenous fistulas (DAVF), which are usually vascularized by long and intricate meningeal networks. In such situations, NBCA may not be able to reach the lesion itself, rendering the embolization ineffective. We present a new technique that improves distal distribution of NBCA glue.Methods The technique described in this report consists of injecting dextrose 5% through the guiding catheter simultaneously with the superselective injection of NBCA glue into the targeted feeding branch. The technique is illustrated with three cases of posterior fossa DAVF.Results In the reported cases, flooding the territory of the targeted vessel with non-ionic dextrose 5% allowed deep progression of the glue by delaying contact with ionic substances. Excellent distribution of the NBCA glue reaching the site of the arteriovenous shunts was thus obtained despite suboptimal proximal microcatheter tip positions.Conclusion Simultaneous perfusion of dextrose 5% through the guiding catheter during NBCA injection dramatically improves the distal progression of glue through small, tortuous arterial feeders. This technique has the potential to increase the therapeutic value of transarterial embolization for DAVFs.     

Embolization of intracranial dural arteriovenous fistulas with Onyx-18

Background and purpose

The use of Onyx in the treatment of AVMs has been reported in the literature, but experience in the treatment of DAVF is lacking. We report the clinical outcome obtained in the treatment of dural arteriovenous fistulas (DAVFs) using a new liquid embolic agent, Onyx-18.

Methods

The present series included 21 patients; 9 had DAVFs draining directly into the cortical veins, 6 had DAVFs draining directly into the dural sinus, 4 had DAVFs draining through the ophthalmic veins and 2 had DAVFs involving the dural sinus with leptomeningeal retrograde venous drainage Clinical data were extracted from hospital files and all patients were followed.

Results

In 14 patients (70%) there was complete angiographic elimination of the shunts and resolution of the symptoms. The remaining 7(30%) patients was not cured with residual shunts. Adverse events occurred in 6(30%) of 21 patients with 1 DAVF located at the transverse sigmoid sinus, 2 at tentorium, and 3 at the cavernous sinus. Cranial deficits occurred in 3(15%) patients, brain infarction in 1(5%) patient and microcatheter gluing in 1(3.2%) patient. At final follow up, 20 patients were asymptomatic with 1 showed clinical improvement.

Conclusion

Definitive cure may be attained effectively with Onyx in dural arteriovenous fistulas and adjunctive to surgery and radiotherapy. Location of the DAVFs affected the outcome of transarterial embolization.     

Computed tomographic and digital subtraction angiography evaluation of ophthalmic-ethmoidal artery dural arteriovenous fistula

Ophthalmic-ethmoidal dural arteriovenous fistula (DAVFs) is a rare type of dural arteriovenous fistulas and usually presenting with spontaneous subarachnoid hemorrhage, subdural hemorrhage or ocular symptoms. We present a case of a 59-year old gentleman presenting with acute headache, vomiting and generalized weakness. CT study of the brain revealed a large left frontal hematoma and abnormal aneurysmal sac with dilated cortical vein, communicating with the superior sagittal sinus. Conventional angiography confirmed diagnosis of ruptured ophthalmic-ethmoidal DAVF, resulting in a frontal intra-axial hemorrhage. Anterior fossa DAVFs are extremely rare, difficult to diagnose and treat. CT angiography is initial method of diagnosis, but digital substruction angiography remains the gold standard of confirming dural fistulas.     

Doppler sonographic evaluation of shunts in patients with dural arteriovenous fistulas

BACKGROUND: AND PURPOSE: Doppler sonography has been used to assess global cerebral circulation time (CCT) in healthy volunteers and a small number of patients with cerebral arteriovenous malformations. We evaluated the effect of arteriovenous shunts on global CCT in patients with dural arteriovenous fistulas (DAVFs) by using this Doppler echo contrast-bolus tracking test. METHODS: We measured CCT as the time delay in a contrast bolus to the internal carotid artery (ICA) and internal jugular vein (IJV) in 13 patients with DAVF and 30 age-matched control subjects. Mean CCT and mean arterial and venous rise times (Delta t = 80% of total signal-intensity increase) were compared. Posttreatment follow-up measurements were performed in five patients. RESULTS: Mean CCT and venous Delta t were significantly different between patients and controls (CCT, 1.1 +/- 0.9 vs 6.9 +/- 1.2 seconds, P <.0001; venous Delta t, 5.2 +/- 2.0 vs 7.0 +/- 2.6 seconds, P =.024), but arterial Delta t values were not (4.4 +/- 1.8 vs 4.7 +/- 2.0 seconds). Posttreatment follow-up of two occluded fistulas showed CCT normalization. One near-occlusion showed a two-step increase in signal intensity, and incomplete occlusion in two patients left the CCT unchanged. One patient with an extracranial, highly vascularized glomus tumor draining into the IJV had a CCT of 1.8 seconds. CONCLUSION: In DAVF patients, sonographic CCT is significantly shortened. Our test is highly sensitive for arteriovenous shunts but not specific for DAVF alone. Follow-up measurements in DAVF patients are well correlated with results of angiographic treatment. CCT assessment might become an additional tool for evaluating these patients and monitoring their treatment.     

Diagnosis of spinal dural arteriovenous fistula with multidetector row computed tomography: a case report

Spinal dural arteriovenous fistulas are a rare cause of myelopathy. Nonspecific symptoms may delay the diagnosis. Magnetic resonance imaging and spinal angiography are routinely used to establish the diagnosis. In our case abnormalities on magnetic resonance imaging only suggested spinal dural arteriovenous fistulas. Multidetector row computed tomography (MRCT) led to the diagnosis which was confirmed by angiography.