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.     

Angiographically occult epidural arteriovenous fistula of the craniocervical junction

BACKGROUND: Spinal dural and intradural arteriovenous fistulas (AVFs) have been the subject of numerous reports but purely epidural AVFs causing venous congestion within the spinal cord are rare. CASE DESCRIPTION: We describe a patient with an exclusively epidural arteriovenous fistula and congestive myelopathy. There are three interesting features of this case as described below: 1) The presence of a purely epidural AVF of the cranio-cervical junction. According to our knowledge this is the first case of an AVF in this location. 2) The lesion was angiographically occult. This was probably because of the extremely slow flow of the fistula. 3) Despite the negative angiograms, exploratory surgery was conducted because of positive clinical and MR findings. CONCLUSIONS: Epidural AVF/AVM of the foramen magnum should be considered in the differential diagnosis in patients with chronic myelopathy, even if cranial and spinal angiograms are negative. In these cases, we recommend that if clinical and radiological investigations strongly suggest the presence of an arteriovenous fistula, surgical exploration should be performed.     

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.     

Myelopathy caused by tentorial dural arteriovenous fistula: a rare case report

A 51-year-old man with myelopathy due to intracranial dural arteriovenous fistula (dural AVF) is reported. At age 46, the patient experienced subarachnoid hemorrhage caused by rupture of the dural AVF and underwent embolization of the lesion at another hospital. At this time, the patient complained of numbness in his legs and showed paraplegic gait disturbance. MRI scan revealed swelling of the cervical spinal cord. Cerebral angiograms demonstrated the recurrence of tentorial dural AVF fed by bilateral meningohypopheseal trunks and the right posterior inferior cerebellar artery. Arteriovenous shunt (AV shunt) flow was drained into the anterior spinal vein. It seemed that the swelling of the spinal cord and myelopathy was caused by venous hypertension of spinal veins. After surgical interruption of the right petrosal vein which connected dAVF with cerebellar veins, AV shunt was obliterated successfully. Postoperative cerebral angiograms showed disappearance of dural AVF. The patient became ambulant and his cervical spinal cord appeared normal on the postoperative MRI scan. Surgical interruption of the draining vein was simple, effective and essential treatment.     

Cranial and sacral dural arteriovenous fistulas as a cause of myelopathy.

The authors report a series of seven patients with myelopathy who were found to have spinal dural arteriovenous (AV) fistulas in which the nidus was located at some distance from the spinal cord. The nidus was intracranial in three cases and involved a sacral nerve root sheath in the other four; in each case, the arterialized draining vein led into the coronal plexus of medullary veins. A lack of normal draining radicular veins was noted in all cases. Magnetic resonance images were obtained in four patients and demonstrated spinal cord tissue changes only in the lower thoracic cord in three cases and in the cervical cord in one, all consistent with an ischemic process secondary to venous hypertension. Five patients were managed surgically by division of the draining vein, with improvement of the neurological deficit in all. One patient was treated by embolization alone and had stabilization of her deficit. The remaining patient in the series died of unrelated systemic disease before the spinal dural AV fistula could be treated. These cases support the theory that venous hypertension is the dominant pathophysiological mechanism involved in spinal dural AV fistulas independent of their location. In patients with a suspected spinal dural AV fistula, lumbar and thoracic spinal angiography will reveal the site of the fistula in the majority of cases (88% in this series). In the remaining patients, the possibility of a remote fistula must be considered. The lack of normal venous drainage of the cord following injection in the artery of Adamkiewicz is the most reliable indicator of venous hypertension in the cord and can be helpful in making the decision to proceed with a search for a cranial or sacral arterial supply.     

Obliteration of a tentorial dural arteriovenous fistula causing spinal cord myelopathy using the cranio-orbito zygomatic approach

BACKGROUND: Intracranial dural arteriovenous fistulas account for 10 to 15% of all intracranial arteriovenous malformations. Tentorial dural arteriovenous fistulas with spinal medullary venous drainage causing spinal cord myelopathy are very rare, but have been previously described. We describe a case using a cranio-orbito zygomatic approach with intraoperative angiography for the surgical treatment of a tentorial artery dural arteriovenous fistula causing spinal cord myelopathy. CASE PRESENTATION: A 42-year-old male presented complaining of a 1-year history of incoordination and dizziness and a 2-month history of progressive myelopathy with bowel and bladder incontinence. The patient had magnetic resonance imaging (MRI) performed along with cerebral and spinal angiography that revealed a right tentorial artery dural arteriovenous fistula with spinal medullary venous involvement down to T11. Angiographic embolization was attempted, but selective catheterization was unsuccessful. The patient underwent a cranio-orbito zygomatic approach with obliteration of the dural arteriovenous fistula. An intraoperative angiogram confirmed complete obliteration of the dural arteriovenous fistula. CONCLUSION: Intracranial dural arteriovenous fistulas are a rare cause of spinal cord myelopathy. When a patient presents with suspicion of spinal dural fistula and negative spinal angiography, an intracranial origin should be suspected and a cerebral angiogram performed. Skull base approaches along with intraoperative angiography provide an alternative modality for obliteration of the dural arteriovenous fistula nidus, thereby eliminating the venous congestion and hence the spinal cord ischemia.     

Spinal epidural arteriovenous fistula with perimedullary drainage. Case report and pathomechanical considerations

The classic angiographically demonstrated features of spinal dural arteriovenous fistulas are shunts of radiculomeningeal branches with radicular veins draining exclusively in the direction of perimedullary veins and thereby causing venous congestion. These shunts are located at the point where the radicular vein passes the dura mater. Spinal epidural arteriovenous shunts, however, normally do not drain into the perimedullary veins and are, therefore, asymptomatic, presumably because of a postulated reflux-impeding mechanism between the dural sleeves. The authors report on a patient in whom an epidural arteriovenous shunt showed delayed retrograde drainage into perimedullary veins, leading to the classic clinical (and magnetic resonance imaging-based) findings of venous congestion. Intraoperatively the angiographically established diagnosis was confirmed. Coagulation of both the epidural shunt zone and the radicular vein resulted in complete obliteration of the fistula, as confirmed on repeated angiography. This rare type of fistula should stimulate considerations on the role of valvelike mechanisms normally impeding retrograde flow from the epidural plexus to perimedullary veins and suggest that, in certain pathological circumstances, epidural fistulas can drain retrogradely into perimedullary veins as an infrequent variant of spinal arteriovenous shunts.     

Case of cervical paraspinal arteriovenous fistulae with a huge intracanalicular varix successfully treated with transvenous embolization

Paraspinal arteriovenous fistulas (AVFs), with the fistulas draining into the epidural veins alone, are relatively rare and few cases have been reported until now. We reported a case of cervical paraspinal AVFs draining only into the epidural venous plexus without reflux into the intradural venous system. The patient showed myelopathy due to direct compression of the spinal cord by a large varix. A 57-year-old man presented with gait disturbance. Neurological findings on admission revealed that tetraparesis, sensory disturbance of four extremitas below the C5 level and bladder bowel dysfunction. Magnetic resonance imaging and computed tomography at the cervical level disclosed remarkable compression of the spinal cord by a large venous pouch at the C6 level. Digital subtraction angiography (DSA) revealed paraspinal arteriovenous fistulas fed by bilateral C6 radicular arteries, the right ascending cervical arteries, and the right deep cervical artery in the right C6 intervertebral foramen. Three-staged transarterial embolization was performed by selective catheterization of the multiple feeders with n-butylcyanoacrylate, followed by transvenous embolization. During transvenous embolization, motor evoked potential (MEP) monitoring was performed. After retrograde catheterization of the epidural venous plexus, the large varix was occluded with Guglielmi detachable coils. The AV fistulas were completely occluded without any change in MEP monitoring during the procedure. The patient's gait improved well after the procedure and follow up DSA six months later showed no recurrence of the paraspinal AVFs.     

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.     

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.     

Progressive myelopathy caused by dural arteriovenous fistula at the craniocervical junction--case report.

A 68-year-old male presented an unusual dural arteriovenous fistula (AVF) located at the craniocervical junction. Magnetic resonance imaging revealed dilated perimedullary veins around the spinal cord at C-1 and C-2 levels, as well as high intensity signals in the spinal cord on T2-weighted images. Vertebral angiography identified an AVF at the point where the right vertebral artery penetrates the dura. The fistula was a single and direct communication between the vertebral artery and the spinal vein. Surgical interruption of the fistula at its venous side resulted in prompt improvement of both motor and sensory signs and symptoms.     

Intraoperative microdoppler monitoring for spinal dural arteriovenous fistulae

BACKGROUND: One of the most important goals in the surgical treatment of spinal dural arteriovenous fistulae is complete interruption of the flow in the fistula. To confirm complete interruption, we use intraoperative microdoppler monitoring. METHODS: Three patients with spinal dural arteriovenous fistulae with perimedullary venous drainage underwent surgical treatment using microdoppler monitoring. All of them suffered from congestive myelopathy before treatment. Microdoppler monitoring was performed on the perimedullary draining vein to detect the arterial spectrum before and after the interruption of the arteriovenous shunt. RESULTS: In all patients, an arterial spectrum was detected on the dorsal perimedullary vein. Sequential monitoring demonstrated the effects of each surgical procedure, which included epidural coagulation of the fistulae or intradural ligation of the retrogradely draining radiculomedullary veins. After complete interruption of the fistula, the arterial spectrum disappeared completely. In a patient with duplicated dural arteriovenous fistulae, the direction of the flow of the second arteriovenous shunt could be demonstrated by microdoppler monitoring combined with temporary clipping. This is especially useful in a complex case with duplicated fistulae. In all patients, postoperative angiography demonstrated complete disappearance of the arteriovenous fistulae. The patients all showed remarkable improvement with no therapeutic morbidity. CONCLUSION: Intraoperative microdoppler monitoring is an easily available and useful technique to safely confirm complete obliteration of spinal dural arteriovenous fistulae.     

Spontaneous spinal epidural arteriovenous fistulae in neurofibromatosis type-1

BACKGROUND: NF-1 is one of the most common autosomal-dominantly inherited genetic disorders with an incidence of approximately 1:3500. We report a case and review the literature to characterize spontaneous spinal AVF that occur in neurofibromatosis (NF-1). CASE REPORT: A 51-year-old woman presented with NF-1 and progressive radiculomyelopathy. Angiography revealed an AVF terminating in a giant intraspinal epidural varix extending paraspinally through the C3/4 neural foramen. Trapping of the AVF attempted 18 years earlier prevented endovascular access for embolization, and vigorous bleeding made direct surgical resection impossible. Therefore, as palliation, arterial feeding collaterals were occluded, and surgically exposed tortuous veins were packed with coils. Laminectomies and partial resection of the epidural varix resulted in subtotal occlusion with clinical improvement. CONCLUSION: The spinal AVF associated with NF-1 appears to show dominant venous drainage to the intraspinal extradural and paraspinal venous plexus without evidence of intradural drainage. The vertebral artery is typically the origin of the fistula. A giant venous varix and numerous collateral feeders to the vertebral artery may give an AVM-like appearance. Clinically, the fistulae produce a syndromic triad including symptoms of NF-1, progressive radiculomyelopathy, and a bruit. Treatment is direct attack on the fistula by either surgery or embolization. If, however, a direct approach cannot be chosen, occlusion of feeding vessels combined with laminectomies can result in long-term symptomatic improvement.     

Vascular malformations of the spinal cord and dura

Current techniques of diagnosis and treatment allow for earlier detection, precise delineation of the vascular anatomy, and, most important, successful treatment of most patients with spinal AVMs. Magnetic resonance imaging is useful in the initial assessment of patients with progressive myelopathy but cannot replace myelography or arteriography in screening patients who may have a spinal AVM. The most common variety of spinal AVM is a dural arteriovenous fistula. Dural arteriovenous fistulas cause cord injury by producing venous congestion, and symptoms can be reversed by elimination of venous congestion of the spinal cord. Dural arteriovenous fistulas can be treated successfully by interrupting the arteriovenous fistula either in the dura or by disconnecting the dural fistula from the coronal venous plexus in the subarachnoid space. This can be done by interrupting the medullary vein that drains the arterial blood from the dural fistula into the coronal venous plexus of the spinal cord. Stripping of the engorged venous network on the surface of the spinal cord is unwarranted and may cause further cord injury. In dural arteriovenous fistulas embolization is often beneficial in patients with acute neurologic deterioration, to permit time for stabilization and improvement in spinal cord hemodynamics and in cord function before neurosurgical intervention is undertaken. Embolization also may be indicated in patients with intradural spinal AVMs in which surgery cannot be performed safely. Although embolic occlusion does not permanently occlude most intradural AVMs, it often permits stabilization of neurologic function and may be repeated later if neurologic dysfunction returns or progresses. Although the outcome after treatment is dependent on the type and location of the spinal AVM, as in most treatable neurologic disorders the functional outcome of patients with spinal AVMs is directly related to their neurologic condition at the time of treatment. Patients with minimal dysfunction, and with easily accessible AVMs, such as dural arteriovenous fistulas, have the greatest chance for useful recovery or stabilization. Since these patients represent the largest number of patients with spinal AVMs, they must be diagnosed and treated early to achieve the best possible outcome.     

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.     

Spinal dural arteriovenous fistula associated with a spinal perimedullary fistula: case report

Among spinal cord vascular malformations, dural arteriovenous fistulas (DAVFs) must be distinguished from intradural malformations. The concurrence of both is extremely rare. The authors report the case of a 35-year-old man who suffered from progressive myelopathy and who harbored both a DAVF and an intradural perimedullary fistula. During surgery, both fistulas were identified, confirmed, and subsequently obliterated. The fistulas were located at two levels directly adjacent to each other. Although the incidence of concurrent spinal DAVFs is presumed to be approximately 2%, the combination of a dural and an intradural fistula is exceedingly rare; only two other cases have been reported in the literature. One can speculate whether the alteration in venous drainage caused by the (presumably congenital) perimedullary fistula could possibly promote the production of a second dural fistula due to elevated pressure with concomitant venous stagnation and subsequent thrombosis. The authors conclude that despite the rarity of dual pathological entities, the clinician should be aware of the possibility of the concurrence of more than one spinal fistula in the same patient.     

A sudden C3-C4 tetraplegia revealing an intracranial dural arteriovenous draining into the spinal medullary veins

We report a case of intracranial dural arteriovenous (DAVF) draining into the spinal medullary veins. A 49-year-old woman presented a rapidly progressive ascending myelopathy resulting in a C3-C4 tetraplegia associated with acute respiratory failure at the twelfth hour. MRI revealed swelling of the cervical spinal cord, hyperintensity on T2 and enhancement of enlarged veins on MR angiography. A conventional angiography showed the DAVF with venous drainage into the spinal vein extending to the conus medullaris. After embolization, neurological recovery occurred during the first week, allowing tracheal extubation on day 2. Clinical, radiological and therapeutic aspects of this uncommon pathology are presented.     

Dural arteriovenous fistula presenting as brainstem ischaemia

Summary Dural arteriovenous fistulas presenting with ascending myelopathy are characterised by the presence of an abnormal retrograde drainage through spinal veins. The authors present a case of cranial dural arteriovenous fistula causing brainstem dysfunction secondary to venous hypertension, treated by surgical interruption of the pial venous drainage which resulted in complete clinical and radiological resolution of the brainstem lesion.     

Spinal epidural arteriovenous fistulas associated with progressive myelopathy. Report of four cases

The authors report the cases of four patients who presented with progressive myelopathy (one patient had been asymptomatic for 25 years) due to spinal epidural arteriovenous fistulas (AVFs). Clinical symptoms and magnetic resonance imaging findings were similar to those of dural AVFs. In contrast to dural AVFs, angiography showed that the lesions were fed by multiple vessels and drained in one case in multiple veins. Perimedullary venous drainage was visible in three of the four cases. All fistulas were cured by embolization; arterial access was used in two cases and venous in two. The authors' aim in this paper is to emphasize the differences between dural and epidural AVFs in terms of their physiopathology and angioarchitecture as well as the therapeutic strategy.     

Ventriculoperitoneal shunt failure causing myelopathy in a patient with bilateral jugular vein occlusion. Case report

The authors describe the case of a 36-year-old woman with bilateral internal jugular vein occlusion, hydrocephalus, and Dandy-Walker variant who presented with myelopathy that was ultimately attributed to ventriculoperitoneal (VP) shunt failure. Computed tomography (CT) angiography of the head and neck revealed epidural venous engorgement within the cervical spine, greater that 50% narrowing of the C2-5 spinal canal, and compression of the cervical spinal cord. After successful shunt revision, postoperative CT angiography revealed decreased venous engorgement as well as decompression of the cervical spinal cord, and the patient's myelopathy improved. This case represents a fascinating clinical presentation of VP shunt failure, highlighting the physiological importance of the external jugular pathways involved in cerebral venous drainage.