Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.     

Conus perimedullary arteriovenous fistula with multiple shunt points including the cauda equina: a case report

Perimedullary arteriovenous fistula (AVF) is usually located on the surface of the spinal cord and is fed by the anterior spinal artery and/or the posterior spinal artery. We report a rare case of Conus perimedullary AVF with multiple shunt points including the cauda equina. A 68-year-old man presented with leg pain when walking long distances. Magnetic resonance imaging at the thoracic and lumbar level revealed multiple signal voids with marked cord signal change. Angiography showed the perimedullary AVF fed by the anterior spinal artery from the right T9 intercostal artery at the level of the conus medullaris and the fistula fed by the left lateral sacral artery from the left internal iliac artery at the level of the cauda equina. In the first surgery, we performed surgical interruption of feeding arteries from the filum terminale and coagulated AV shunt of the conus medullaris. However residual perimedullary AVF was found at the conus medullaris in the postoperative angiography. Secondary surgery was carried out to treat residual AVF. Follow-up angiography showed complete disappearance of all AVFs. Postoperatively, the patient`s symptoms were improved. Because the Conus perimedullary AVF has the characteristics of multiple feeding arteies, multiple shunt points, and complex venous drainage, it must be kept in mind that other fistula could exist in the cauda equina or filum terminale.     

Paravertebral arteriovenous fistula treated by endovascular coil embolization

A 41-year-old man, without underlying health problems or traumatic episodes, presented with a rare paravertebral arteriovenous fistula (AVF) causing radiculopathy manifesting as gradually progressive right grip weakness, and right thumb, index, and middle finger numbness. Digital subtraction angiography revealed a high flow, single hole paravertebral AVF fed by the right thyrocervical trunk that drained into the epidural venous plexus. The patient underwent endovascular embolization of the AVF via the transarterial approach. The fistula was completely occluded by coil embolization. Postembolization, clinical symptoms improved and 6-month follow-up angiography showed no recurrence of the fistula. Paravertebral AVF is a rare vascular malformation occurring outside the dura mater, fed by dural or epidural branches, and draining primarily into the epidural venous plexus. Paravertebral AVF is usually asymptomatic because of a "reflux-impending mechanism" within the dural sleeves that prevents retrograde drainage into the perimedullary veins. However, in the present case, mechanical compression of the radicular nerve due to a dilated epidural venous plexus resulted in neurological symptoms. We conclude that endovascular surgery is an effective treatment strategy for paravertebral AVF.     

Surgical Management of Combined Intramedullary Arteriovenous Malformation and Perimedullary Arteriovenous Fistula within the Hybrid Operating Room after Five Years of Performing Focus Fractionated Radiotherapy: Case Report

Perimedullary arteriovenous fistula (AVF) shunts occur on the spinal cord surface and can be treated surgically or by endovascular embolization. In contrast, the nidus of an intramedullary arteriovenous malformation (AVM) is located in the spinal cord and is difficult to treat surgically or by endovascular techniques. The benefits of radiotherapy for treating intramedullary AVM have been published, but are anecdotal and consist largely of case reports. We present a case of combined cervical intramedullary AVM and perimedullary AVF which received surgical treatment within a hybrid operating room (OR) after 5 years of focus fractionated radiotherapy. A 37-year-old male presented with stepwise worsening myelopathy. Magnetic resonance imaging and spinal angiography revealed intramedullary AVM and perimedullary AVF at the C3 to C5 levels. In order to reduce nidus size and blood flow, we first performed focal fractionated radiotherapy. Five years later, the lesion volume was reduced. Following this, direct surgery was performed by an anterior approach using corpectomy in the hybrid OR. The spinal cord was monitored by motor-evoked potential throughout the surgery. Complete obliteration of the fistulous connection was confirmed by intraoperative indocyanine green video-angiography and intraoperative angiography, preserving the anterior spinal artery. We conclude that surgical treatment following focal fractionated radiotherapy may become one strategy for patients who are initially deemed ineligible for endovascular embolization and surgical treatment. Furthermore, the hybrid OR enables safe and precise treatment for spinal vascular disorders in the fields of endovascular treatment and neurosurgery.     

Brain stem ischemia from intracranial dural arteriovenous fistula: case report

BACKGROUND: Intracranial dural arteriovenous fistulas (AVFs) with spinal perimedullary venous drainage are rarely reported, but most of the patients initially have presented with myelopathy or subarachnoid hemorrhage. This is the first report of the intracranial dural AVF patient who presented with brain stem infarction. CASE DESCRIPTION: A 38-year-old woman experienced nausea and vomiting with an acute onset, followed by vertigo. Magnetic resonance imaging showed ischemic lesion in the medulla oblongata, and she was then sent to our hospital. On admission, she had nystagmus, swallowing difficulties, Homer syndrome, and right hemiparesis and hemisensory disturbance. Cerebral angiography revealed dural AVF draining into spinal perimedullary veins at the left transverse-sigmoid sinus. The patient was treated by transvenous embolization under local anesthesia. A microcatheter proceeded to the left sigmoid sinus via the internal jugular vein, and embolization of the sinus was performed using coils without complications. The patient's swallowing difficulties improved over a few days after the embolization, and one month later, there remained only a slight mild hemiparesis and hemisensory disturbance. Six months after the onset, there was no ischemic lesion in the brain stem on magnetic resonance imaging. CONCLUSIONS: In this case, we showed the possibility of brain stem infarction, caused by the intracranial dural AVF.     

Exclusively epidural arteriovenous fistula in the cervical spine with spinal cord symptoms: case report

OBJECTIVE AND IMPORTANCE: We describe the case of an epidural arteriovenous fistula (AVF) in the cervical spine draining only into the epidural and paravertebral plexus. An entirely epidural AVF having such drainage is extremely rare. CLINICAL PRESENTATION: A 24-year-old man presented with a 4-month history of gradually progressive sensory and motor disturbances of the upper and lower extremities. Magnetic resonance imaging and magnetic resonance angiography revealed a peridural vascular lesion within the canal compressing the spinal cord from C5 to T2. Diagnostic angiography revealed a perimedullary and/or dural high-flow AVF, fed mainly by branches of ascending cervical and deep cervical arteries. The fistula drained into the epidural and paravertebral venous plexus without reflux into intradural venous systems. INTERVENTION: Multiple feeders of the AVF were embolized with a Liquid coil and n-butylcyanoacrylate via a two-step procedure. One week after embolization, the AVF was surgically removed. CONCLUSION: Interesting points of this case were the exclusively epidural location of the lesion, the exclusively epidural drainage of the AVF, and the etiology of the symptoms. Venous drainage of the fistula had no relation to any dural or intradural veins. Initially, spinal cord and nerve root compression by extradural veins with varicose dilation seemed to cause the radiculopathy and/or the myelopathy, and subsequent myelopathy caused by spinal venous hypertension was believed to be the main etiology in this case.     

Characteristics and treatment of dural and perimedullary arteriovenous fistula at the craniocervical junction presenting with subarachnoid hemorrhage

Dural and perimedullary arteriovenous fistula (AVF) at the craniocervical junction tend to cause subarachnoid hemorrhage (SAH). However, their natural history and clinical manifestations still remain to be elucidated. From 2003 to 2009, we encountered 5 cases of dural and perimedullary AVF presented with SAH. They were all male, ranging in age from 53 to 85 year-old (mean: 68 year-old). Rebleeding occurred in 1 patient on day 11. Outcome estimated by modified Rankin Scale did not change remarkably from 2.6 on admission to 2.4 at 3 months later on average. Cerebral angiography and 3D-CT angiography disclosed feeders originating from radicular or intracranial vertebral arteries which drained into the epidural venous plexus or spinal meningeal veins. One patient died of systemic complication during his clinical course. Thus we performed open surgery in the remaining 4 patients. Of these, we failed to occlude feeders completely in the initial surgery without intraoperative digital subtraction angiography (DSA) in 2 patients. Following this treatment we performed coil embolization and repeated open surgery with the aid of intraoperative DSA, respectively. In 1 patient out of the remaining 2 patients, we utilized intraoperative DSA to confirm complete disappearance of AVF composed of multiple feeders. These observations show that SAH caused by dural and perimedullary AVF at the craniocervical junction should be mainly treated by open surgery with the aid of intraoperative DSA in order to accomplish obliteration of the feeders because, otherwise, we might fail to confirm complete disappearance of AVF.     

Cervical perimedullary arteriovenous fistula in an infant presenting with subarachnoid hemorrhage--case report

A 9-month-old boy was transferred to our institute after suffering sudden seizure and loss of consciousness followed by cardiopulmonary arrest. Neurological examination on admission revealed deep coma and tetraparesis. Brain computed tomography revealed diffuse intracranial subarachnoid hemorrhage (SAH), whereas brain magnetic resonance (MR) angiography showed no intracranial abnormalities. MR imaging of the spine demonstrated a remarkable flow void extending from C3 to T1. Digital subtraction angiography revealed a perimedullary arteriovenous fistula (AVF) fed by the left thyrocervical trunk, associated with a varix and a dilated perimedullary vein. He had hypoxic encephalopathy due to transient cardiopulmonary arrest, and remained in the intensive care unit for 2 months. Thereafter, he was transferred to the pediatric ward, where his general condition improved, and after 7 months underwent embolization of the AVF to prevent further SAH. The perimedullary AVF was successfully interrupted by transarterial embolization with n-butyl-2-cyanoacrylate and platinum coils, and no additional neurological deficits developed. Post-embolization MR imaging showed loss of the flow void. The favorable outcome demonstrates the importance of spinal cord imaging in infants with SAH without other intracranial abnormalities to detect the presence of perimedullary AVF. Perimedullary AVFs in children are often associated with huge fistulas and varices, so are good candidates for endovascular surgery.     

Intracranial dural arteriovenous fistula associated with progressive cervical myelopathy and normal venous drainage of the thoracolumbar cord: case report and review of the literature

BACKGROUND: Intracranial dural arteriovenous malformations draining into the perimedullary venous system are rare lesions. In these cases, the selective spinal catheterization of all vessels with potential of causing that malformation was negative, and additional cerebral angiography usually reveals the fistula. Because of venous congestion of the cord caused by the DAVF, a delayed drainage or stagnation of contrast material in the artery of Adamkiewicz was considered as a compelling angiographic disorder so far. CASE DESCRIPTION: We report about a 58-year-old patient with a DAVF of the right posterior fossa draining into the cervical and upper thoracic plexus of medullary veins, followed by progressive cervical myelopathy and a normal venous drainage of the artery of Adamkiewicz. Because of the failing endovascular treatment option, the neurosurgical intervention was performed. The fistula was explored and clipped without any complications. Immediately after operation, the patient reported an improvement of his neurological deficits. CONCLUSION: About 38 cases of intracranial DAVFs draining into the perimedullary venous system are reported, but to our knowledge, this is the second one with a normal drainage of the artery of Adamkiewicz. The pathophysiological mechanisms, diagnostic procedures, and treatment modalities are discussed.     

Endovascular treatment of intracranial dural arteriovenous fistulas with spinal perimedullary venous drainage.

Intracranial dural arteriovenous (AV) fistulas with spinal perimedullary venous drainage are rare lesions that have distinctive clinical, radiological, and therapeutic aspects. Five patients presented with an ascending myelopathy, which extended to involve the brain stem in three cases. Myelography and magnetic resonance imaging showed slightly dilated spinal perimedullary vessels. Spinal angiograms were normal in the arterial phase. Diagnosis was only possible after cerebral angiography, which demonstrated posterior fossa AV fistulas fed by meningeal arteries and draining into spinal perimedullary veins. Endovascular treatment alone resulted in angiographic obliteration of the lesion in three patients. Two patients required surgery in addition to endovascular therapy. One patient died postoperatively, and in one a transient complication of embolization was observed. Improvement after treatment was good in two cases and fair in two. Transverse sinus thrombosis was observed in three cases and was probably the cause of the aberrant venous drainage of the fistula into the spinal perimedullary veins. The pathophysiology is related to spinal cord venous hypertension. These lesions were classified as Type 5 in the Djindjian and Merland classification of dural intracranial AV fistulas. Endovascular therapy is a safe effective method in the treatment of these fistulas and should be tried first.     

Venous embolization of dural arterio-venous fistulas. Transcranial approach under neuronavigation

OBJECT: Transvenous embolization is an effective treatment for dural arterio-venous fistulas. In the event of dural sinus thrombosis, embolization can be performed by direct puncture via craniectomy. We report our experience with transcranial venous embolization in two patients. METHODS: Two patients underwent transcranial venous embolization of a type-III dural arterio-venous fistula of the transverse sinus. The craniectomy was performed with neuronavigation assistance. RESULTS: The surgical approach consisted in a minimal exposure of the sinus with a drill. Neuronavigation allowed accurate placement of the craniectomy. The endovascular treatment was performed in a second stage, enabling complete and stable occlusion of the fistula in both patients. CONCLUSION: This combined treatment of dural AVFs associating craniectomy and transcranial puncture of the sinus is simple and efficient when retrograde navigation through the internal jugular vein cannot be achieved. Neuronavigation is helpful in accurately positioning the craniectomy.     

A case report of spinal dural AV fistula which showed drastic recovery

Spinal dural AVF is the most common type of spinal AVMs. It affects especially old male with slowly progressive paraparesis in most cases. We have experienced a rare case of a middle aged male with spinal dural AVF who showed rapid deterioration in its course. The patient was treated with surgical interruption of AVF after transarterial embolization with NBCA. The patient improved well after the treatment, and intramedullary lesion on MRI disappeared after 4 years. The authors would like to stress the importance of early diagnosis and proper treatment for spinal dural AVFs.     

Dural arteriovenous fistula associated with meningioma: spontaneous disappearance after tumor removal

A 45-year-old woman presented with a non-dominant transverse-sigmoid sinus dural arteriovenous fistula (AVF) associated with convexity meningioma on the same side. The dural AVF disappeared spontaneously after surgical removal of the meningioma, even though there was no manipulation of the dural AVF. Dural AVFs are usually acquired lesions, and may develop after trauma, surgery, and dural sinus thrombosis. Dural AVFs of the acquired origins are rarely associated with brain tumor. Dural AVFs associated with a tumor may develop even in the absence of sinus occlusion.     

Perimedullary arteriovenous fistula at the craniocervical junction - case report -

Perimedullary arteriovenous fistulas (AVFs) at the craniocervical junction are uncommon, and are often fed by the anterior spinal artery, with only a few cases fed by the intradural vertebral artery (VA). A 55-year-old man presented with a case of perimedullary AVF fed by the VA at the craniocervical junction manifesting as subarachnoid hemorrhage. Left vertebral angiography demonstrated an AVF supplied by branches from the VA. Three-dimensional computed tomography angiography (3D-CTA) revealed that the feeding arteries originated from the VA at the intradural position. Two feeding arteries were coagulated and dissected, followed by coagulation of a small feeder. The draining veins became discolored and shrank. 3D-CTA performed 2 months after the operation revealed disappearance of the AVF. Open surgery was successfully performed for the almost perimedullary AVF at the craniocervical junction, and is considered to be preferable for the treatment of this disease.     

Angiographic aspects and management of dural arteriovenous fistulas

The angiographic analysis of a dural arteriovenous fistula (AVF) is a determinant step in the evaluation of the lesion with regard to its prognosis and treatment. The clinical presentation of the dural AVFs is very dependent on the venous drainage, and the classification of these lesions draws attention to the venous drainage pattern, combining the clinical course and the venous drainage angiographic features. Dural AVFs with retrograde venous drainage into the leptomeningeal veins are associated with an increased incidence of intracranial hemorrhage, neurological deficits, and increased intracranial pressure allowing impairment of cognitive functions and dementia. Other risky findings are venous dilatations and dural sinus stenosis/occlusion. Different therapeutic approaches are available including noninvasive, endovascular, and surgical techniques. However, the treatment of dural AVFs should be considered in relation to the different types of lesions carrying different clinical presentation and prognosis. Prompt treatment allowing complete and permanent cure is mandatory in dural AVFs with an aggressive clinical course and/or with radiological findings predicting a severe prognosis.     

A case of pial single-channel cerebral arteriovenous fistula

A 60-year-old man presented with dizziness, dysarthria, and right hemifacial palsy with sudden onset. Computed tomography scan revealed a small cerebellar hematoma near the left flocculus. Since the site of the hemorrhage was atypical for cerebellar hemorrhages, emergency angiography was performed and revealed a pial single-channel arteriovenous fistula (AVF) in the early arterial phase with drainage into the dilated perimedullary vein. The feeding artery was a peripheral branch of the left anterior inferior cerebellar artery. There were no angiographical findings indicating a nidus or capillary network. The patient underwent left lateral suboccipital craniotomy. A small dilated perimedullary vein and an abnormally red spherical varix were found during the operation. A peripheral branch of the left anterior inferior cerebellar artery was thought to be a feeder because it seemed to be firmly attached to the dilated vein. Based on the operative technique for dural AVFs, electrocoagulation of the varix was performed aiming at obliteration of the fistula. The postoperative angiogram demonstrated the obliteration of the fistula and of the early filling vein. Feeders of cerebral AVF are cerebral arteries. A pial single-channel AVF is defined as a vascular malformation with a single venous channel in communication with one or more arteries with no intervening nidus or vessels. To date, reports in the literature of cerebral arteriovenous fistula have been very few. Its clinical entities such as origin, bleeding rate and the necessity of surgery remain subjects of debate. Here we report our experience and discuss its issues of the treatment we used.     

Intracranial dural arteriovenous fistula showing diffuse MR enhancement of the spinal cord: case report and review of the literature

BACKGROUND: Cervical myelopathy resulting from intracranial dural arteriovenous fistula (AVF) is uncommon. Knowledge of the magnetic resonance imaging (MRI) appearance of such lesions is important because many patients with myelopathy are initially examined by MRI, and an incorrect diagnosis could result in delayed or improper treatment. We describe a rare case of myelopathy due to an intracranial dural AVF showing diffuse enhancement of the cervical spinal cord. CASE DESCRIPTION: A 64-year-old male presented with progressive myelopathy and respiratory insufficiency. Cerebral angiography disclosed an AVF at the craniocervical junction draining intrathecally into the spinal medullary veins. MRI revealed dilated perimedullary vessels around the craniocervical junction, as well as spinal cord swelling with high signal intensity changes. Diffuse intense enhancement of the cervical spinal cord was also seen on postcontrast images. Embolization via the afferent artery was successfully performed, and the fistula was then microsurgically obliterated via a lateral suboccipital approach. This procedure arrested a rapidly progressive myelopathy. CONCLUSION: Intracranial dural AVF showing diffuse enhancement of the spinal cord is extremely rare, and this enhancement effect may indicate pathologic changes of the spinal cord. MRI only is not useful for diagnosis, but also for demonstrating pathologic changes and predicting the outcomes of patients with intracranial dural AVF.     

Endovascular Treatment of Transverse-Sigmoid Sinus Dural Arteriovenous Malformations Presenting as Pulsatile Tinnitus

Transverse-sigmoid sinus dural arteriovenous malformations (DAVM) are uncommon vascular lesions for which complete cure may be difficult to obtain. A wide variety of treatments for these lesions include observation, arterial compression, surgical resection, and endovascular embolization. We propose that transverse-sigmoid sinus DAVM can be completely cured by occluding the ipsilateral dural sinus with detachable balloon and Guglielmi detachable coils (GDC) coils before arterial feeder embolization with histoacryl. Three patients who presented with pulsatile tinnitus and normal magnetic resonance imaging (MRI) studies underwent angiography, which demonstrated transverse-sigmoid sinus DAVM. All three patients wer treated with retrograde transvenous sinus embolization with complete occlusion of the transverse-sigmoid sinus with detachable balloons and GDC coils with preservation of the vein of Labbé. Subsequently, the various feeders from the external carotid artery were embolized. The tentorial arteries arising from the ipsilateral internal carotid arteries were not embolized in any of the cases, which were still contributing to the DAVM. Complete cure with thrombosis of the tentorial branch of the internal carotid artery (ICA) was seen on follow-up angiogram 1 day after embolization in one patient and on 4-week and 6-week follow-up angiograms in the other two patients. Complete occlusion of the transverse sinus proximal to the vein of Labbé, in spite of incomplete arterial feeder embolization, can result in complete cure of the transversesinus dural AVF if adequate time is given for the remaining feeders to occlude, once the fistula is obliterated.     

Factors that affect the surgical outcomes of spinal dural arteriovenous fistulas

BACKGROUND: Authors disclose the factors that affect the surgical outcome of the spinal dural AVFs from the retrospective analysis of 13 cases. METHODS: Thirteen patients with spinal dural AVF underwent microsurgical treatments between 1990 and 2004 at the Department of Neurosurgery, Aso Iizuka Hospital. The mean age was 62 years, and the median time to diagnosis was 38 months (range, 4-120 months). There were 12 men and 1 woman. The clinical features were characterized by spastic paraparesis in all 13 patients and micturition problem in 11 patients. All 13 patients showed the longitudinal extension of the high T2 intramedullary signals in magnetic resonance (MR) image. The microsurgical obliterations of the spinal dural AVFs were performed for all 13 patients because the endovascular treatments were difficult or failed to obliterate the lesions. RESULTS: The durations of the symptoms were not directly correlated to the preoperative neurological conditions and the postoperative outcomes. The patient's age and the preoperative severity of myelopathy affected the postoperative outcomes. The mode of the longitudinal extension of the high T2 intramedullary signals in MR image, rostral or caudal, did not show the statistical significance to the outcome. The poor outcomes were observed in elderly patients and patients with preoperative modified Rankin Scale 4 and 5. A case with multiple spinal dural AVFs is also presented. CONCLUSION: The spinal AVFs are treatable lesions through microsurgery or embolization. The likelihood of favorable outcome was affected by the severity of deficits and the patient's age.     

Usefulness of three-dimensional digital subtraction angiography in endovascular treatment of a spinal dural arteriovenous fistula

The use of 3D digital subtraction (DS) angiography provides a better understanding of spinal vascular lesion architecture. The authors report on 2 cases involving a spinal dural arteriovenous fistula (DAVF) and demonstrate the usefulness of 3D DS angiography for endovascular treatment of these spinal DAVFs. In both cases, middle-aged male patients suffered from bilateral leg hypesthesia, gait disturbance, and urinary dysfunction several months before treatment. Spinal angiography revealed DAVFs that were fed by a radicular artery branching from the intercostal artery and draining veins proceeding superiorly along the perimedullary veins. Endovascular embolization was performed in both cases. Selective 3D DS angiography of the intercostal artery clearly demonstrated the tortuous course of the feeder and the relationship among the feeding artery, fistula point, and draining veins in each case. This information was very useful in selecting a working angle for manipulating the microcatheter and for glue injection. In addition, the maximum intensity projection image from rotational DS angiography data clearly showed the fistula point at the dural sleeve and feeder entering the spinal canal via the intervertebral foramen and the relationship with the bone structure. Successful obliteration of the fistulae was achieved in both cases. Selective spinal 3D DS angiography was very useful in understanding the complex spinal vascular architecture and in choosing the best working angle and therapeutic strategy for endovascular treatment of spinal DAVFs.