In situ photocoagulation of spinal dural arteriovenous malformations using the Nd:YAG laser.

Spinal dural arteriovenous malformations (AVM's) are the most common type of AVM involving the spinal cord in adults. Direct obliteration of the fistula nidus located in the dura is the preferred method of treatment. Five cases of spinal dural AVM were treated by open surgical exposure, microsurgical disconnection of the dural nidus from the coronal venous plexus, and in situ obliteration of the nidus using the Nd:YAG laser. Use of the Nd:YAG laser reduced nidus obliteration to a simple 10-minute technical exercise. All patients improved neurologically following surgery, and complete obliteration of all lesions was verified by delayed angiography. There were no permanent complications related to either the surgical exposure or the use of the Nd:YAG laser. Open surgical treatment of spinal dural AVM's using the Nd:YAG laser appears to be a safe, effective, and durable method of treating these lesions. Photocoagulation is discussed in the context of the other treatment modalities available.     

Management of spinal dural arteriovenous malformations

Dura-based spinal arteriovenous malformations (AVM's) are being diagnosed with increasing frequency. The optimal management of such lesions remains a topic of discussion. In an effort to guide this discussion, the authors review their experience with 17 cases of spinal dural AVM treated between January, 1984, and July, 1987. All patients presented with a slowly progressive paraparesis. The abnormalities were initially identified on myelography and confirmed by selective spinal angiography. Fourteen patients underwent endovascular embolization as a primary treatment, and a total of 18 embolization procedures were performed. After all but two of these, obliteration was confirmed at angiography. Patients' symptoms improved following 15 or these procedures but early improvement was not sustained in 10 instances; patients were unchanged after two procedures and worse after one. Follow-up angiography was performed at varying intervals after 15 of the 18 procedures, and recanalization of the previously obliterated spinal dural AVM was demonstrated in 13 instances. Eight patients ultimately underwent surgical treatment of their dura-based spinal AVM. No patient suffered deterioration of symptoms following operation. While embolization may allow angiographic obliteration of a spinal dural AVM and early clinical improvement, for the majority of patients these are not sustained. The average time to treatment failure was 5 months. Newer embolization materials will be necessary to effect permanent treatment in many of these patients.     

Dural arteriovenous malformations of the spine. Clinical features and surgical results in 55 cases

The clinical and angiographic findings of 55 patients with a spinal dural arteriovenous malformation (AVM) are reviewed, and the results of surgery assessed. The symptoms of dural AVM are usually gradual in onset, and hemorrhage from this type of AVM is less common than in true spinal cord angiomas. Other clinical features and the myelographic findings are similar to those of spinal cord angiomas. On angiography, the nidus of dural AVM's usually projected lateral to the spinal cord. Clipping of communicating vessels between the AVM and the coronal plexus was carried out in 50 patients, and decompressive laminectomy only in five cases. Surgery led to improvement of disturbed gait or arrest of a previously progressive course in 85% of those managed by clipping communicating vessels. The pathophysiology and surgical treatment of dural AVM's are discussed.     

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 arteriovenous malformations: a comparison of dural arteriovenous fistulas and intradural AVM's in 81 patients

The medical records and arteriograms of 81 patients with spinal arteriovenous malformations (AVM's) were reviewed, and the vascular lesions were classified as dural arteriovenous (AV) fistulas or intradural AVM's. Intradural AVM's were further classified as intramedullary AVM's (juvenile and glomus types) and direct AV fistulas, which were extramedullary or intramedullary in location. Dural AV fistulas were defined as being supplied by a dural artery and draining into spinal veins via an AV shunt in the intervertebral foramen. Intramedullary AVM's were defined as having the AV shunt contained at least partially within the cord or pia and receiving arterial supply by medullary arteries. Of the 81 patients, 27 (33%) had dural AV fistulas and 54 (67%) had intradural AVM's. Several dissimilarities in clinical and radiographic findings of the two subgroups were evident. The patients with intramedullary AVM's were younger; the age at onset of symptoms averaged 27 years compared to 49 years for dural AV fistulas. The most common initial symptom associated with dural AV fistulas was steadily progressive paresis, whereas hemorrhage was the most common presenting symptom in cases of intramedullary lesions. No patients with dural AV fistulas had subarachnoid hemorrhage. Activity exacerbated symptoms more frequently in patients with dural lesions. Associated vascular anomalies occurred only in cases of intradural AVM's. In 96% of the dural lesions the AV nidus was in the low thoracic or lumbar region; in only 15% did the intercostal or lumbar arteries supplying the AVM also provide a medullary artery which supplied the spinal cord. In contrast, most intradural AVM's (84%) were in the cervical or thoracic segments of the spinal cord and all of them were supplied by medullary arteries. Transit of contrast medium through the intradural AVM's was rapid in 80% of cases, suggesting high-flow lesions. Forty-four percent of the patients with AVM's of the spinal cord had associated saccular arterial or venous spinal aneurysms. No dural AV fistulas displayed these characteristics. A good outcome occurred in 88% of patients with dural AV fistulas after nidus obliteration, while 49% of patients with intramedullary AVM's did well after surgery or embolization. These findings suggest that dural and intradural AVM's differ in etiology (acquired vs. congenital) and that they have different pathophysiology, radiographic findings, clinical presentation, and response to treatment.     

Assistance of intraoperative microvascular Doppler in the surgical obliteration of spinal dural arteriovenous fistula: cases description and technical considerations

BACKGROUND: Intraoperative microvascular Doppler may be valuable in assisting in the surgical obliteration of dural arteriovenous fistula of the spinal cord. It enables identification, through flow spectrum analysis, of the anatomic components and haemodynamic features of this type of vascular malformation. METHODS: In two cases, intraoperative microvascular Doppler was used to assist in the surgical obliteration of dural arteriovenous fistula of the spinal cord. The fistulas were identified prior to the dura opening, and for this only minimally invasive surgery was required. Direct recordings of the arterialised draining vein and the nidus of the fistula demonstrated a pathological spectrum caused by the arterial supply and the disturbed venous outflow in which a high-resistance flow pattern and low diastolic flow resembling an arterial-like flow velocity were observed. FINDINGS: The fistulas were obliterated by interruption of the draining vein, and Doppler measurements provided information on flow velocity changes in the medullary veins from an arterial to a venous pattern. The absence of any residual flow in the draining vein confirmed successful haemodynamic treatment. INTERPRETATION: Intraoperative microvascular Doppler recording is valuable assistance in surgical closure of spinal arteriovenous fistula.     

Surgical management of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb

Dural arteriovenous fistulas located in the vicinity of the jugular foramen are complex vascular malformations and belong to the most challenging skull base lesions to treat. The authors comprehensively analyze multiple features in a series of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb. Four patients who underwent surgery via the transcondylar approach to treat dural arteriovenous fistulas around the jugular foramen were retrospectively reviewed. Previously, endovascular treatment was attempted in all patients. The success of the surgical treatment was examined with postoperative angiography. Complete obliteration of the dural arteriovenous fistulas (DAVFs) was achieved in three patients, and significant flow reduction in one individual. All patients had a good postoperative outcome, and only one experienced mild hypoglossal nerve palsy. Despite extensive bone drilling, an occipitocervical fusion was necessary in only one patient with bilateral lesions. The use of an individually tailored transcondylar approach to treat dural arteriovenous fistulas at the region of the jugular foramen is most effective. This approach allows for complete obliteration of the connecting arterial feeders, and removal of bony structures containing pathological vessels.     

The Treatment of dural AVM by embolization with aron alpha (Ethyl-2-cyanoacrylate)

The authors report four cases of dural arteriovenous malformation (AVM) treated by a modified technique of embolization. Three cases had posterior fossa dural AVM and one had bilateral supratentorial dural AVM. The authors think that the best way to treat dural AVM is to close its nidus completely. This could be achieved by a safe and easy technique of embolization. The material used for embolization should intimately adhere to the vascular network and should not become fragmented. We used aron alpha (Ethyl-2-cyanoacrylate). This is a biological glue and it sets in a solid membranous form instantaneously on coming into the contact with an ionic medium. It does not get fragmented. Aron alpha was injected into the nidus of the AVM through a cannula inserted only into the main feeding artery in four cases of dural AVM reported here. Postoperative angiography showed complete obliteration of the AVM's, they did not fill either from the treated artery or from the untreated feeding arteries. The technique is easy and safe. There was no operative or postoperative complication. All the patients have remained asymptomatic to date, i.e. 2, 2, 6 and 7 1/2 years after the procedure.     

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.     

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.     

Spinal dural arteriovenous fistula with hematomyelia caused by intraparenchymal varix of draining vein

Background ContextHemorrhage that results from spinal dural arteriovenous fistula (Type I arteriovenous malformation [AVM]) is uncommon. There are some reports of subarachnoid hemorrhage and subdural hematoma caused by Type I spinal AVM, but there are few reported cases of hematomyelia caused by spinal dural arteriovenous fistula.PurposeTo describe an interesting patient who had hematomyelia caused by a dural arteriovenous fistula (Type I spinal AVM).Study designA case report.MethodsWe present a case of a 51-year-old man who presented acute onset epigastric pain, paraplegia, and sensory loss below his nipples. Magnetic resonance imaging and selective spinal angiogram demonstrated hematomyelia, subarachnoid hemorrhage, and spinal arteriovenous fistula fed by the right Th7 intercostal artery. By laminotomy of Th6–8, the varix-like draining vein and intramedurally hematoma were partially removed and the arterial supply was interrupted by coagulation of the right Th7 segmental artery.ResultsOne month after surgery, he regained movement against gravity at the left ankle and toe but no functionally significant improvement.ConclusionsIt must be kept in mind that spinal dural arteriovenous fistulas (Type I spinal AVM) has possibility of hematomyelia origin, despite the fact that it is extremely rare.     

Thrombosis of a spinal arteriovenous malformation after hemorrhage: case report

BACKGROUND: Thrombosis of cerebral arteriovenous malformations (AVM) and spinal dural arteriovenous fistulas following hemorrhage rarely have been reported. Rarer still is thrombosis of spinal AVMs following hemorrhage. CASE DESCRIPTION: A 6-year-old boy presented with sudden low back and sciatic pain, bilateral leg weakness, and an intramedullary spinal cord hematoma. Spinal angiography demonstrated dilated feeding arteries without shunting, and no intervention was performed. Over time, these enlarged arteries reduced in caliber, and the patient recovered fully. CONCLUSIONS: The rarity of spinal AVMs and AVM thrombosis make their coincidence in this case unique. Although surgical intervention would have enabled definitive diagnosis of the spinal AVM, it is not mandatory in the absence of arteriovenous shunting. What is mandatory, however, is continued angiographic surveillance, particularly in pediatric patients.     

Unusual clinical manifestations of dural arteriovenous malformations

Fourteen patients had classical angiographic findings of intracranial dural arteriovenous malformations (AVM's). They presented with unusual central neurological signs and symptoms, including visual disturbances, hemiparesis, speech disturbances, gait ataxia, diffuse increased intracranial pressure, and intracranial hemorrhage. In 12 of the 14 patients there was a direct correlation between the clinical presentation and the venous drainage characteristics of the AVM's. The symptoms were probably related to a regional steal phenomenon in two patients. Six patients had direct surgical excision of the dural AVM. Five patients underwent endovascular embolization of the malformation and, in one case, the AVM was removed surgically after embolization. In one patient, the external carotid artery in the neck was ligated. Ten of the 14 patients had substantial clinical improvement or cure. A complete anatomical obliteration of the malformation was obtained in seven cases. None of the patients deteriorated clinically after therapy.     

A case of ruptured aneurysm associated with spinal arteriovenous malformation presenting with hematomyelia: case report

BACKGROUND

Spinal cord arteriovenous malformation (AVM) associated with spinal aneurysm is not particularly rare, but cases presenting with hematomyelia are relatively rare compared to those with subarachnoid hemorrhage (SAH). We report a rare case of successfully treated spinal AVM associated with ruptured aneurysm presenting with hematomyelia.

CASE DESCRIPTION

A 52-year-old male was admitted to our hospital with sudden onset of tetraplegia, respiratory disturbance, and superficial sensory disturbance. Computed tomography revealed hematomyelia at the level of C3–4. Gadolinium-enhanced magnetic resonance imaging showed small, enhanced lesions. Angiography revealed an intradural perimedullary arteriovenous malformation associated with two aneurysms on the feeding arteries. Administration of high-dose methylprednisolone gradually ameliorated his symptoms. Direct surgical obliteration was performed on the 30th day after the onset. The bilateral C3 cervical radicular arteries and the nidus were coagulated. Angiography performed after surgery showed neither the aneurysms nor the nidus. He was discharged with only mild weakness in the left upper extremity and mild left hypesthesia 3 months after surgery, and was fully independent.

CONCLUSION

We report a case of hematomyelia caused by ruptured aneurysm associated with spinal arteriovenous malformation that was successfully treated with surgical obliteration.     

Spinal dural arteriovenous fistulas: a plea for neurosurgical treatment

Summary Spinal dural arteriovenous fistulas are the most common type of arteriovenous malformation involving the spinal cord, especially in middle-aged men. We report 21 patients with this malformation who had signs and symptoms of myelopathy. The diagnosis was established by selective spinal angiography in patients whose neurological deficits, myelograms or magnetic resonance tomographies suggested the presence of a spinal arteriovenous fistula. They were treated by microsurgical coagulation of the fistula nidus located in the dura and intradural division of the draining vein. Twenty patients improved neurologically following surgery, one remained unchanged. Complete obliteration of all lesions was verified by intra-operative microvascular Doppler sonography and in 3 cases by postoperative angiography. There were only a few minor and transient complications after surgery: one neurological deterioration where venous thrombosis was suspected, one cerebrospinal fluid accumulation and, in one case a transient wound healing impairment. Two patients had to be operated on again. In one case with difficult localization of a fistula at the L5/S1 level, the fistula was still visible in the postoperative angiogram. In another patient, a spinal epidural haematoma occurred a few hours after surgery. We conclude that microsurgical treatment of spinal dural arteriovenous fistulas is a safe, fast, simple and effective method of treating these lesions. However, recovery after surgical management was often incomplete because the diagnosis was established too late and the patient already presented with severe and long-lasting deficit. Thus, the main problem remains a diagnostic and not a surgical one. This paper is dedicated to Professor Fritz Loew, Chief-editor emeritus of Acta Neurochirurgica     

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.     

Staged treatment of arteriovenous malformations of the brain

Twenty-eight patients treated for arteriovenous malformations (AVMs) of the brain had staged therapy consisting of multiple surgical procedures or endovascular embolization followed by surgical treatment. There were 10 men and 18 women, aged 15 to 60 years (mean, 34 years). The clinical symptoms were those associated with intracranial hemorrhage in 13 patients, progressive neurological deficit not due to hemorrhage in 6, intractable headache in 5, and seizures in 4. Four groups were identified based upon the reason for staging therapy. Thirteen patients with large high flow AVMs (Group A) had staged treatment because of the risk of normal perfusion pressure breakthrough. The initial afferent artery occlusion was accomplished surgically in 9 patients and by endovascular embolization in 4. Postoperatively, no patient in this group had malignant cerebral edema or intracranial hemorrhage suggestive of normal perfusion pressure breakthrough, but 1 patient had an intraventricular hemorrhage after initial embolization. In 9 patients (Group B), the AVM had a complex multiple arterial supply that precluded resection from a single operative exposure. Seven had supratentorial AVMs, and 2 had AVMs of the posterior fossa. In 6 of these cases, the AVM was located in the midline and received bilateral arterial input. Six patients had staged surgical procedures, and 3 had an initial endovascular embolization followed by operation. Two patients had intracerebral hemorrhages, one after an initial surgical procedure and another after initial embolization. In 4 patients (Group C), the AVM had a major dural component that was treated separately from the parenchymal component. In 3 of these patients, embolization through the external carotid artery satisfactorily obliterated the dural component; in the remaining patient, a persistent internal carotid supply necessitated resection of the dural malformation. The parenchymal component was excised surgically in 2 patients. Two patients (Group D) had separate surgical procedures to treat an aneurysm associated with a parenchymal AVM. Overall, 19 of 28 patients had complete excision and 9 had partial obliteration of their AVMs. Late follow-up of 27 patients at a mean of 18.6 months showed that 16 patients were in excellent condition and 8 were in good condition. Three patients were in poor condition with debilitating neurological deficits. One patient had a delayed intracranial hemorrhage 22 months after incomplete obliteration of her AVM. Staged treatment of selected AVMs of the brain may avoid the occurrence of normal perfusion pressure breakthrough.(ABSTRACT TRUNCATED AT 400 WORDS)     

Minimally invasive surgical closure of a spinal dural arteriovenous fistula

OBJECTIVE AND IMPORTANCE: The treatment of a spinal dural arteriovenous fistula (DAVF) via a minimally invasive approach utilizing a tubular retraction system is described. CLINICAL PROBLEM: Spinal dural arteriovenous fistulas are treated by either direct surgical obliteration or endovascular embolization to close the fistula. Surgical treatment traditionally requires a full or hemi-laminectomy with intradural exposure and obliteration of the draining vein of the fistula. TECHNIQUE: Surgical treatment is performed via a targeted, minimally invasive approach to close the draining vein of the DAVF intradurally utilizing a tubular retraction system. CONCLUSION: Surgical treatment of spinal DAVFs can be performed in a targeted, minimally invasive manner with a short operative time and minimal tissue disruption.     

A case of secondary anterior fossa dural arteriovenous fistula following posterior fossa craniotomy

The etiology of dural arteriovenous fistula (AVF) remains uncertain. The authors present a case presenting with anterior fossa dural AVF, which developed after the resection of cerebellar arteriovenous malformation (AVM). The anterior fossa dural AVF, which was not observed on the preoperative angiography, was diagnosed on the follow-up angiography, after the resection of cerebellar AVM. A mechanism underlying the present case is not clearly understood. To the best of our knowledge, some cases of dural AVF secondary to craniotomy have been reported. It is postulated that intracranial vascular anomaly should be analyzed after the surgery.     

Outcome after the treatment of spinal dural arteriovenous fistulae: a contemporary single-institution series and meta-analysis

OBJECTIVE: Spinal dural arteriovenous fistulae (Type I spinal AVMs) are the most common type of spinal vascular malformations. The optimal treatment strategy has yet to be defined, and endovascular embolization is being offered with increasing frequency. A 7-year single-institution retrospective review of outcome with surgical management of Type I spinal AVMs is presented along with a meta-analysis of existing literature. METHODS: For the institutional analysis, a retrospective review of all patients who underwent treatment at our institution for Type I spinal AVMs was performed. Between 1995 and the present (the time frame during which endovascular treatments were available), 19 consecutive patients were treated. Follow-up was performed by clinical examination or telephone interview, and functional status was measured by use of the Aminoff-Logue score. For the meta-analysis, a MEDLINE search between 1966 and the present was performed for surgical, endovascular, or combined treatment of spinal dural arteriovenous fistula. These series were included in a meta-analysis to evaluate success and failure rates, complications, and functional outcome. Specifically, embolization and microsurgery were compared. RESULTS: For the institutional analysis, 18 of 19 patients were available for long-term follow-up after surgery. There were no surgical failures, but one complication was seen. Patients demonstrated a statistically significant improvement in gait and bladder function after surgery. For the meta-analysis, 98% of those patients treated with microsurgery had their dural arteriovenous fistulae successfully obliterated after the initial treatment, compared with only 46% with embolization, as judged by radiographic or clinical follow-up. 89% percent of patients demonstrated improvement or stabilization in neurological symptoms after surgical treatment. Few complications were demonstrated with either surgery or embolization. CONCLUSION: At this point, surgery seems to be superior to embolization for the management of spinal dural arteriovenous fistula. The fistula is usually obliterated after the initial treatment, with few clinical or radiographic recurrences. The majority of patients either improve or stabilize after treatment. Few worsen, and the morbidity is minimal. It is reasonable to attempt initial embolization, especially at the time of the initial diagnostic spinal angiogram. The treating physicians and patients should be aware of the high chance of recurrence, and patients may ultimately require surgery or repeat embolization. After endovascular therapy, patients are committed to repeat angiography and probably embolization. For these reasons, it is the authors' opinion that surgery should be used as the first-line therapy for spinal dural arteriovenous fistulae.