Recanalization of spinal arteriovenous malformations following embolization

Combined surgical and endovascular approach to treat a ventrally located perimedullary arteriovenous fistula

Perimedullary arteriovenous fistulae (PMAVFs) (also called type IV spinal cord arteriovenous malformations) are rare lesions. They are located in the subarachnoid space or just under the pia. The shunt occurs between the anterior spinal artery (ASA) and/or posterior spinal artery (PSA) and a network of perimedullary veins. The aim of the treatment, surgical or endovascular, is to occlude the fistula. This article presents a unique treatment strategy of a demanding strictly ventral PMAVF in the lower thoracic cord. A posterior surgical approach with spinal cord rotation followed by direct puncture of a distally located arterial feeder was achieved. Precise identification of the fistula with superselective contrast injections was obtained and accurate catheterization of the venous pouch with a microcatheter was performed. Complete occlusion of the PMAVF was achieved with coils.

Long term follow-up of endovascular management of spinal cord arteriovenous malformations with emphasis on particle embolization

Objective

To determine long term safety and efficacy of endovascular treatment of spinal cord arteriovenous malformations (AVMs), with calibrated particle embolization as a firstline approach.

Methods

We reviewed clinical and imaging data of consecutive patients who underwent endovascular treatment for both nidal and fistulous type spinal cord AVMs in our center, from 1990 to 2015. Outcome at the last follow-up was assessed by an independent observer.

Results

Embolization of spinal cord AVMs was performed in 61 patients, including 46 (75%) with particles (exclusively in 29 patients), 30 (49%) with cyanoacrylate, and 6 (10%) with combined surgical treatments. Particle embolizations were iterative in 33 patients (median number of sessions 5 (range 3–6)). Neurological deterioration after treatment occurred in 5 patients (cyanoacrylate=4, surgery=1, particles=0; P<0.001). At a median follow-up of 6 years (range 3–13 years), angiographic cure was obtained in 11/61 (18%) patients (nidal type=6/53 (11%), fistulous type=5/8 (63%)). In progressive forms, neurological improvement occurred in 16/28 (57%) patients, stabilized in 9/28 (31%), and worsened in 3/28 (12%). In hemorrhagic forms, the rebleeding rate was 4/14 patient years without standard treatment, 0/322 patient years in partial iterative treatment, and 0/15 patient years in angiographically cured lesions (P=0.001).

Conclusion

Our study suggests that particle embolization as a firstline therapy to treat spinal cord AVMs is safe and offers long term efficacy, especially for those with small, distal, and multiple shunts. Partial occlusion of the AVM may be sufficient to prevent rebleeding, without the potential risks of complete occlusion. Particle calibration and injection technique, ‘one by one’, are critical to safety. Cyanoacrylate embolization or surgery remains necessary if particle embolization fails to occlude large shunts.

Timing, severity of deficits, and clinical improvement after surgery for spinal dural arteriovenous fistulas

OBJECTIVE

Spinal dural arteriovenous fistulas (dAVFs) are rare vascular abnormalities caused by arteriovenous shunting. They often form at the dural root sleeve between a radicular feeding artery and draining medullary vein causing venous congestion and edema, decreased perfusion, and ischemia of the spinal cord. Treatment consists of either surgical ligation of the draining vein or selective embolization via an endovascular approach. There is a paucity of data on which modality provides more durable and effective outcomes.

METHODS

The authors performed a retrospective review of a prospectively maintained database by the senior author to assess clinical outcomes in patients undergoing surgical treatment of spinal dAVFs. Preoperative and postoperative motor and Aminoff-Logue Scale (ALS) scores were collected.

RESULTS

A total of 41 patients with 44 spinal dAVFs were identified, with a mean patient age of 64 years. The mean symptom duration was 14 months, with weakness (82%), urinary symptoms (47%), and sensory symptoms (29%) at presentation. The fistula locations were as follows: 30 thoracic, 9 lumbar, 3 sacral, and 2 cervical. Five patients had normal motor and ALS scores at presentation. Among the remaining 36 patients with motor deficits or abnormal gait and micturition at presentation, 78% experienced an improvement while the remaining 22% continued to be stable. There was a trend toward improved outcomes in patients with shorter symptom duration; mean symptom duration among patients with clinical improvement was 13 months compared with 22 months among those without improvement. Additionally, rates of improvement were higher for lower thoracic and lumbosacral dAVFs (85% and 83%) compared with those in the upper thoracic spine (57%). No patient developed recurrent fistulas or worsening neurological deficits.

CONCLUSIONS

Surgery is associated with excellent outcomes in the treatment of spinal dAVFs. Early diagnosis and treatment are critical, with a trend toward improved outcomes. No patient in this study had fistula recurrence or worsening of symptoms. Among patients with abnormal motor or ALS scores, 78% improved after surgery. Therapeutic embolization is an option for some lesions, but for cases with unfavorable anatomy where embolization is not feasible, surgery is a safe option associated with high success.

Spinal cord

We first present a brief historic review of developments in the understanding of spinal cord clinical neuroanatomy and neurophysiology over the past 200 years. We then discuss the technical aspects that apply to the examination of the human spinal cord giving details on the interrelations between the spinal cord and the overlying structures, including the meninges and vertebrae. The subsequent discussion focuses on diseases of the spinal cord. Diseases that affect the spinal cord are vascular disease, diseases of spinal column, trauma, developmental abnormalities, central nervous system degenerative disease, inflammatory disease, metabolic and nutritional myelopathies, and tumors. We summarize our knowledge regarding general reactions of spinal cord tissue to disease, in particular Wallerian degeneration of descending/ascending tracts and axonal reaction. Two categories of disease will be covered in depth: vascular disease of the spinal cord, including a review of normal vascular anatomy, and diseases of the vertebral column that can affect the cord secondarily.

Spinal Dural Arteriovenous Fistula: A Review

Spinal dural arteriovenous fistula (SDAVF) is a rare disease, the etiology of which is not entirely clear. It is the most common vascular malformation of the spinal cord, comprising 60-80 % of the cases. The clinical presentation and imaging findings may be nonspecific and misleading, often mistaking it for other entities like demyelinating or degenerative diseases of the spine.This chapter describes the imaging findings, clinical signs, and symptoms of this disease and also the available treatment options according to the current literature.Angiography is still considered the gold standard for diagnosis; however, MRI/MRA is increasingly used as a screening tool. Modern endovascular techniques are becoming increasingly more effective in treating SDAVF offering a less invasive treatment option; however, they still lag behind surgical success rates which approach 100 %. The outcome of both treatment options is similar if complete obliteration of the fistula is obtained and depends mainly on the severity of neurological dysfunction before treatment.Heightened awareness by radiologists and clinicians to this rare entity is essential to make a timely diagnosis of this treatable disease. A multidisciplinary treatment approach is required in order to make appropriate treatment decisions.

Spinal Dural Arteriovenous Fistula: Imaging Features and Its Mimics

Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. Magnetic resonance imaging findings such as spinal cord edema and dilated and tortuous perimedullary veins play a pivotal role in the confirmation of the diagnosis. However, spinal angiography remains the gold standard in the diagnosis of SDAVF. Classic angiographic findings of SDAVF are early filling of radicular veins, delayed venous return, and an extensive network of dilated perimedullary venous plexus. A series of angiograms of SDAVF at different locations along the spinal column, and mimics of serpentine perimedullary venous plexus on MR images, are demonstrated. Thorough knowledge of SDAVF aids correct diagnosis and prevents irreversible complications.

Intramedullary hemorrhage from a thoracolumbar dural arteriovenous fistula

BACKGROUND CONTEXT

Spinal dural arteriovenous fistulas (AVFs) are acquired lesions presenting typically with neurologic deficits secondary to chronic congestive myelopathy. The low-flow and low-volume nature of these lesions makes hemorrhage very unlikely, and intramedullary hemorrhage caused by thoracolumbar dural AVFs is exceedingly rare.

PURPOSE

The purpose of this study was to report a case of intramedullary hemorrhage caused by a thoracolumbar dural AVF.

STUDY DESIGN/SETTING

The study design included a case report and review of literature.

METHODS

A case of intramedullary hemorrhage from a thoracolumbar dural AVF was reported, and the literature regarding hemorrhagic presentations of dural AVF was reviewed.

RESULTS

A 66-year-old woman presented with a sudden onset of abdominal pain, paraplegia, sensory loss below the costal margins, and urinary retention. Magnetic resonance imaging scan showed intramedullary hemorrhage with abnormal flow voids raising suspicion of an intramedullary AV malformation. However, subsequent selective spinal angiography demonstrated a spinal dural AVF fed by the T7 intercostal artery and a varix within the draining vein. Complete obliteration of the dural AVF and the varix was achieved via embolization. As far as we are aware, there are only two other similar cases in the literature. Literature review revealed that presentation of thoracolumbar dural AVFs with hemorrhage is frequently associated with accelerated venous flow and the presence of a venous varix.

CONCLUSIONS

Although very unusual, a spinal dural AVF may present with intramedullary hemorrhage, and hemorrhage in such conditions may be associated with an accelerated venous flow and the presence of a venous varix.

Clinical features and treatment outcomes of the spinal arteriovenous fistulas and malformations

Object

Spinal vascular diseases, such as spinal dural arteriovenous fistulas (DAVFs), perimedullary arteriovenous fistulas (AVFs), and spinal arteriovenous malformations (AVMs), are very rare. The authors analyzed the features and treatment outcomes of these conditions.

Methods

Data from 64 patients were retrospectively reviewed. There were 33 spinal DAVFs (1 patient had 2 lesions), 20 perimedullary AVFs, and 12 spinal AVMs. Clinical features, radiological findings, treatment results, and clinical outcomes were evaluated according to the diseases, subtypes, and treatment modalities. The median duration of follow-up was 20, 42, and 56 months for spinal DAVFs, perimedullary AVFs, and spinal AVMs, respectively.

Results

Spinal DAVFs showed faster progression of symptoms (median 5, 12, and 36 months for spinal DAVFs, perimedullary AVFs, and spinal AVMs, respectively) and worse neurological status at diagnosis (poor neurological status in 56%, 65%, and 33%, respectively). On MRI, signal voids were demonstrated in all except 1 spinal DAVF. At the last follow-up, 94% of spinal DAVFs, 68% of perimedullary AVFs, and 50% of spinal AVMs were completely obliterated. Favorable clinical outcomes were achieved in 91%, 95%, and 58%, respectively. In detail, the majority (78%) of spinal DAVFs were embolized, resulting in complete obliteration in 92% and favorable clinical outcomes in 92%. Most Type IVa and IVb perimedullary AVFs were surgically treated (71% and 88%), with complete obliterations of 86% and 71%, and favorable clinical outcomes in 100% and 86%, respectively. All Type IVc lesions were embolized with a low cure rate of 40%; however, clinical outcomes were satisfactory. Spinal AVMs were generally embolized (67%), and only glomus-type lesions attained a satisfactory cure rate (80%) and clinical outcome (100%).

Conclusions

Embolization produced satisfactory outcomes in spinal DAVFs and glomus-type spinal AVMs. Surgery is advantageous in Type IVa and IVb perimedullary AVFs. Palliative embolization can be effective in Type IVc perimedullary AVFs and juvenile spinal AVMs.

Spinal glomus (type II) arteriovenous malformations: a pooled analysis of hemorrhage risk and results of intervention

BACKGROUND

The natural history and treatment results for spinal glomus (type II) arteriovenous malformations (AVMs) remain relatively obscure.

OBJECTIVE

To calculate spinal glomus (type II) AVM hemorrhages rates and amalgamate results of intervention.

METHODS

We performed a pooled analysis via the PubMed database through May 2012, including studies with at least 3 cases. Data on individual patients were extracted and analyzed using a Cox proportional hazards regression model to obtain hazard ratios for hemorrhage risk factors.

RESULTS

The annual hemorrhage rate before treatment was 4% (95% confidence interval [confidence interval]: 3%-6%), increasing to 10% (95% CI: 7%-16%) for AVMs with previous hemorrhage. The hazard ratio for hemorrhage after hemorrhagic presentation was 2.25 (95% CI: 0.71-7.07), increasing to 13.0 within the first 10 years (95% CI: 1.44-118). The overall rates of complete obliteration were 78% (95% CI: 72%-83%) for surgery and 33% (95% CI: 24%-43%) for endovascular treatment. Long-term clinical worsening occurred in 12% of patients after surgical treatment (95% CI: 8%-16%) and in 13% after endovascular treatment (95% CI: 7%-21%). No hemorrhages occurred after complete obliteration. After partial surgical treatment, the annual hemorrhage rate was 3% (95% CI: 1%-6%); no hemorrhages were reported over 196 patient-years after partial endovascular treatment.

CONCLUSION

Spinal glomus (type II) AVMs with previous hemorrhage, particularly within 10 years, demonstrated a greater risk of hemorrhage. Complete obliteration and even partial endovascular treatment significantly decreased their hemorrhage rate.

Endovascular treatment for dural arteriovenous fistula at the foramen magnum: report of five consecutive patients and experience with balloon-augmented transarterial Onyx injection

BACKGROUND

Foramen magnum dural arteriovenous fistulas (DAVF) with perimedullary venous drainage represent a small minority of intracranial DAVF, and only a number of small series with limited cases have been reported. The purpose of this retrospective study is to summarize experience of transarterial Onyx embolisation in the treatment of these lesions, with emphasis on the balloon-augmented technique.

METHODS

Five consecutive patients with DAVF at the foramen magnum were treated by transarterial embolisation using the Onyx system. Their symptoms included myelopathy (n=4) and SAH (n=1). Suppliers were from the vertebral artery (VA) (n=4), occipital artery (OA) (n=4), and ascending pharyngeal artery (APA) (n=2), with drainage to the perimedullary veins. After catheterization of the dilated supplier, the fistulous connections, proximal draining veins and appropriate distal segment of the feeders of these DAVF were transarterial embolized using Onyx-18. In three patients, balloon-augmented technique was used to assist embolisation. The technical feasibility of the procedure, angiographic results, and clinical outcome were evaluated.

RESULTS

In every case, complete obliteration was achieved. Neither intraprocedural vessel rupture nor other procedure-related complications occurred. The results remained stable in all patients on follow-up angiograms (mean, 7.2 months). At the last clinical follow-up (mean, 17.6 months), two patients showed complete resolution of the initial symptoms, and three patients showed significant improvement.

CONCLUSION

We found that Onyx embolisation is a feasible and safe alternative to open surgery in the treatment of selective DAVF at the foramen magnum. The balloon-augmented technique widens indications for transarterial Onyx packing of these lesions, and improved safety of the procedure.

Surgical treatment of Type I spinal dural arteriovenous fistulas

Object

Type I spinal dural arteriovenous fistulas (SDAVFs) are low-flow vascular shunts fed by radicular arteries in patients who most often present with myelopathy. Although some fistulas are amenable to endovascular embolization, nearly all can be treated with direct microsurgical obliteration.

Methods

The authors reviewed their experience in treating 214 craniospinal arteriovenous malformations and/or fistulas over the last 8 years. Of these, 19 were spinal (9%), of which 15 (79%) were Type I SDAVFs. The authors reviewed the patients' epidemiological characteristics, presenting symptoms, and SDAVF angioarchitecture in all cases. They subsequently analyzed surgical obliteration rates and outcomes of all 11 patients who underwent fistula microsurgical obliteration.

Results

In all patients who underwent microsurgical treatment, complete angiographic obliteration of the fistula was achieved. At follow-up, 10 (91%) of 11 patients exhibited improvement, 1 patient (9%) was the same, and no patients were worse. Specifically, 8 (73%) of 11 patients had improvement in strength and sensation, 5 (71%) of 7 had improvement of bowel/bladder function, and 3 (60%) of 5 had improvement of preoperative paresthesias. There were no wound infections, CSF leaks, or permanent neurological deficits.

Conclusions

Microsurgical treatment of SDAVF provides direct access to the fistula point, allowing for high obliteration rates with excellent long-term improvement of preoperative deficits and limited periprocedural complications.

Microsurgical management of glomus spinal arteriovenous malformations: pial resection technique: Clinical article

OBJECT

Intramedullary, or glomus, spinal arteriovenous malformations (AVMs) are rare vascular lesions amenable to resection with or without adjuvant embolization. The authors retrospectively reviewed the senior author's (R.F.S.'s) surgical series of intramedullary spinal AVMs to evaluate clinical and radiographic outcomes.

METHODS

Detailed chart and radiographic reviews were performed for all patients with intramedullary spinal AVMs who underwent surgical treatment between 1994 and 2011. Presenting and follow-up neurological examination results were obtained and graded using the modified Rankin Scale (mRS) and McCormick Scale. Surgical technique, outcomes, complications, and long-term angiographic studies were reviewed.

RESULTS

During the study period, 20 patients (10 males and 10 females) underwent resection of glomus spinal AVMs. The mean age at presentation was 30 ± 17 years (range 7-62 years). The location of the AVMs was as follows: cervical spine (n = 10), thoracic spine (n = 9), and cervicothoracic junction (n = 1). The most common presenting signs and symptoms included paresis or paralysis (65%), paresthesias (40%), and myelopathy (40%). Perioperative embolization was performed in the majority (60%) of patients. Pial AVM resection was performed in 17 cases (85%). Angiographically verified AVM obliteration was achieved in 15 patients (75%). At a mean follow-up duration of 45.4 ± 52.4 months (range 2-176 months), 14 patients (70%) remained functionally independent (mRS and McCormick Scale scores ≤ 2). One perioperative complication occurred, yielding a surgical morbidity rate of 5%. Three symptomatic spinal cord tetherings occurred at a mean of 5.7 years after AVM resection. No neurological decline was observed after endovascular and surgical interventions. No deaths occurred. Long-term angiographic follow-up data were available for 9 patients (40%) at a mean of 67.6 ± 60.3 months (range 5-176 months) following AVM resection. Durable AVM obliteration was documented in 5 (83%) of 6 patients.

CONCLUSIONS

Intramedullary AVMs may be safely resected with satisfactory clinical and angiographic results. The pial resection technique, which provides subtotal AVM nidus resection, effectively devascularized these lesions, as confirmed on postoperative angiography, without violating the spinal cord parenchyma, thereby potentially reducing iatrogenic injury.

Endovascular embolization for symptomatic perimedullary AVF and intramedullary AVM: a series and a literature review

INTRODUCTION

Perimedullary arteriovenous fistula (AVF) has shunt on the spinal cord surface and it can be treated with surgery, or endovascular embolization. Intramedullary arteriovenous malformation (AVM) has its nidus in the cord and is difficult to treat either by surgery or endovascular technique. We report our experience with endovascular embolization in the treatment of perimedullary AVF and intramedullary AVM.

METHODS

Four consecutive cases of spinal perimedullary AVF and six intramedullary AVM were retrospectively reviewed. These cases were evaluated and treated at Beijing Tiantan Hospital, China, over a 2-year period. A review of previously reported cases was also performed.

RESULTS

There was no significant difference in the presentations (P = 0.348), level of lesions (P = 0.350), arterial suppliers (P = 0.801), and associated vascular anomalies between perimedullary AVF and intramedullary AVM, except for age (P = 0.014) and treatment modalities (P = 0.003). The patients with perimedullary AVFs were younger in our cases; the age at onset of symptoms averaged 25.8 years compared to 31.7 years for intramedullary AVMs. There was a significant male predominance for both lesions, and a significantly higher incidence of subarachnoid hemorrhage than in spinal dural AVFs. Regarding treatment, endovascular coil embolization is frequently used in perimedullary AVF and liquid embolic agent is an effective therapeutic choice in intramedullary AVM.

CONCLUSION

Perimedullary AVF and intramedullary AVM are dissimilar with dural AVF in clinical characteristics. Our experience suggests that the endovascular treatment of spine perimedullary AVFs and intramedullary AVMs is feasible and effective. Endovascular treatment for intramedullary AVMs is still challenging, the main problem is acute ischemia injury of the spinal cord.

Clinical outcome of treatments for spinal dural arteriovenous fistulas: results of multivariate analysis and review of the literature

STUDY DESIGN

This study was a case series study using a prospective single-institute database for the treatment of spinal dural arteriovenous fistulas (SDAVFs).

OBJECTIVE

To evaluate clinical factors that influence the neurological outcomes of treatment for SDAVFs, which were obtained from the analysis of 21 patients treated in our institution, and to provide management recommendations based on the review of former major clinical studies including our own reported over the past 2 decades.

SUMMARY OF BACKGROUND DATA

Since 1977, when Kendall and Logue described the etiology of SDAVFs as hyperpressure of intrathecal veins due to an abnormal shunting from the arteries, treatment strategies have improved dramatically along with developments in neuroimaging, endovascular techniques and materials, and microsurgery based on the underlying pathophysiological process. However, therapeutic guidelines remain controversial.

METHODS

Patients treated for SDAVFs from 2000 to 2008 were eligible. Age, sex, level of shunting, initial symptom, duration of symptom, the treatment method, and clinical symptoms before and 6 months after treatment were investigated.

RESULTS

There were a total of 30 patients (18 male and 12 female), with a mean age of 59 years; 21 of them underwent treatment for the first time. We conducted a univariate analysis using a logistic regression model, on age, sex, the level of SDAVFs, duration of symptoms, symptom (sensory or paralysis), and gait function and micturition before treatment, and the intervention method were set as variables to investigate the risk factors for motor deficit 6 months after the treatment. Only gait function before treatment was correlated with the motor deficit 6 months after treatment (odds ratio = 10.0; 95% confidence interval = 1.28-78.11, P = 0.03).From these results, intervention at an early stage would be the key to a preferable outcome of the treatment for SDAVFs.

CONCLUSION

The clinical status before treatment significantly influenced the clinical outcome after the treatment.

Surgical treatment of spinal dural arteriovenous fistulae: a consecutive series of 154 patients

BACKGROUND

Embolization of spinal dural arteriovenous fistulae (SDVAFs) has emerged as an alternative to surgery. However, surgical disconnection is a simple and effective procedure.

OBJECTIVE

To review results and complications of surgical treatment of 154 consecutive SDAVFs.

METHODS

The records of 154 consecutive patients with SDAVFs were retrospectively reviewed.

RESULTS

There were 120 males and 34 females (male/female ratio 3.5:1, mean age 63.6 years). The SDAVFs were located at the thoracic level in 92 patients and at the lumbar and sacral spine levels in 45 and 15 patients, respectively. The most common presenting symptoms were motor dysfunction (65 patients), sensory loss (31 patients), and paresthesias without sensory loss (13 patients). The mean interval from symptom onset to definitive diagnosis was 24.7 months (median 12 months). Surgery resulted in complete exclusion of the fistula at first attempt in 146 patients (95%). There were no deaths or major neurological complications related to the surgery. Six percent of patients experienced subjective or objective worsening of preoperative symptoms and signs by the time of discharge that persisted at follow-up. Other surgical complications consisted of wound infection in 2 patients and deep venous thrombosis in 3. Eight patients were lost to follow-up; 141 patients (96.6%) experienced improvement (120 patients, 82.2%) or stability (21 patients, 14.4%) of motor function at last follow-up compared with their preoperative status. Other symptoms such as numbness, sphincter dysfunction, and dysesthesias/neuropathic pain improved in 51.5%, 45%, and 32.6%, respectively.

CONCLUSION

Surgical obliteration of SDAVFs is safe and very effective. Prognosis of motor function is favorable after surgical treatment.

Surgical excision of filum terminale arteriovenous fistulae after lumbar fusion: Value of indocyanine green and theory on origins (a technical note and report of two cases)

BACKGROUND

Intradural filum terminale arteriovenous fistulas (AVFs) are uncommon. We report two cases of this rare entity in which we used indocyanine green (ICG) videoangiography to identify the fistulous connection of each lesion.

CASE DESCRIPTION

Two male patients presented with unresolved lower extremity weakness and paresthesias following lumbar fusion surgery. In each case, angiography showed an AVF between the filum terminale artery (FTA), the distal segment of the anterior spinal artery (ASA), and an accompanying vein of the filum terminale. A magnetic resonance image (MRI) obtained before lumbar fusion was available in one of these cases and demonstrated evidence of the preexisting vascular malformation. Surgical obliteration of each fistulous connection was facilitated by the use of ICG videoangiography. This emerging technology was instrumental in pinpointing fistula anatomy and in choosing the exact segment of the filum for disconnection.

CONCLUSION

Our findings indicate that intradural filum terminale AVFs may have a congenital origin and that ICG is a useful tool in their successful surgical management. As these cases demonstrate, spine surgeons should remain vigilant in evaluating patients based on their clinical symptomatology, even in the presence of obvious lumbar pathology.

Clinical Problem-Solving: Aneurysm or Spinal Arteriovenous Fistula—Bait and Switch

OBJECTIVE:

The authors use an instructive case to review the challenges of diagnosis in subarachnoid hemorrhage (SAH) and to reinforce the nuances of clinical management.

IMPORTANCE:

The presented case highlights critical issues in patient selection and challenges in the diagnosis of SAH and the management of both aneurysmal and arteriovenous fistula-related SAH. The critical points in decision making and diagnosis are discussed, and the case is accompanied by a brief review of the literature on the issues being faced.

CLINICAL PRESENTATION:

The present case is a patient presenting with SAH who was found to have an anterior communicating artery aneurysm. However, clues in the presentation and workup point to another etiology.

CONCLUSION:

A strong history of sudden neck pain before headache and abundance of SAH along the brainstem mandates a need to thoroughly evaluate the source of hemorrhage from cervical vessels through an angiogram.

Secondary clinical deterioration after successful embolization of a spinal dural arteriovenous fistula: a plea for prophylactic anticoagulation

We present a case of delayed aggravation of initially-resolved symptoms in a patient after successful embolization of a T5 spinal dural arteriovenous (AV) fistula with N-butyl cyanoacrylate. The symptoms were attributed to venous thrombosis and resolved with systemic anticoagulation after five days of treatment. Although the most adequate treatment for preventing venous thrombosis after spinal dural AV fistula is not known, we describe this patient as a case for more aggressive prophylactic anticoagulation measures in the immediate post-embolization time period.

Spontaneous occlusion of a spinal arteriovenous malformation: is treatment always necessary?

Knowledge of spinal cord arteriovenous malformations (AVMs) has recently been improved by studies on pathophysiology, neuroimaging, and genetic data. Nevertheless, the natural history of these lesions remains poorly understood.

The authors present the case of an angiographic regression of a nidal-type spinal AVM at T-12 to L-1 in a 46-year-old woman with no risk factors. The natural course of untreated lesions is reviewed and discussed. To the best of the authors' knowledge, this is the first study that reports an angiographically proven complete spontaneous occlusion of a spinal AVM.

A Transmedullary Approach to Occlusion of a Ventral Perimedullary Arteriovenous Fistula of the Thoracic Spinal Cord

OBJECTIVE

A spinal perimedullary arteriovenous fistula (PMAVF) is a direct fistula of one or more spinal arteries into the perimedullary venous network with reversed venous flow and subsequent venous congestion of the spinal cord. The therapeutic goal of surgery is to normalize the venous drainage by obliterating the fistula. Strictly ventral lesions typically require an anterior approach to ensure adequate exposure of the fistula as well and the preservation of the physiological blood supply to the spinal cord.

CLINICAL PRESENTATION

We present a case of a ventral PMAVF at the level of T10 with feeders from the anterior spinal artery, caudally draining veins on the ventral spinal cord, and a dilated transmedullary vein filling cranially draining veins on the dorsal aspect of the spinal cord.

TECHNIQUE

The dilated transmedullary vein was approached by a laminectomy. The vein was coagulated, and the gliotic channel was used to approach the ventral fistula site from the dorsal surface of the spinal cord. Complete obliteration of the fistula was achieved, and the preoperative neurological deficit improved.

CONCLUSION

We conclude that transmedullarly draining veins offers a possible dorsal approach for the occlusion of some ventral PMAVFs, thus avoiding more complex anterior approaches to the ventral spinal cord.

Endovascular management of spinal dural arteriovenous fistulas

Object

Spinal dural arteriovenous fistulas (DAVFs) are the most common spinal vascular malformations and can be a significant cause of myelopathy, yet remain inefficiently diagnosed lesions. Over the last several decades, the treatment of spinal DAVFs has improved tremendously due to improvements in neuroimaging, microsurgical, and endovascular techniques. The aim of this paper was to review the existing literature regarding the clinical characteristics, classification, and endovascular management of spinal DAVFs.

Methods

A search of the PubMed database from the National Library of Medicine and reference lists of all relevant articles was conducted to identify all studies pertaining to spinal DAVFs, spinal dural fistulas, and spinal vascular malformations, with particular attention to endovascular management and outcomes.

Results

The ability to definitively treat spinal DAVFs using endovascular embolization has significantly improved over the last several decades. Overall rates of definitive embolization of spinal DAVFs have ranged between 25 and 100%, depending in part on the embolic agent used and the use of variable stiffness microcatheters. The majority of recent studies in which N-butyl cyanoacrylate or other liquid embolic agents were used have reported success rates of 70–90%. Surgical treatment remains the definitive option in cases of failed embolization, repeated recanalization, or lesions not amenable to embolization. Clinical outcomes have been comparable to surgical treatment when the fistula and draining vein remain persistently occluded. Improvements in gait and motor function are more likely following successful treatment, whereas micturition symptoms are less likely to improve.

Conclusions

Endovascular embolization is an increasingly effective therapy in the treatment of spinal DAVFs, and can be used as a definitive intervention in the majority of patients that undergo modern endovascular intervention. A multidisciplinary approach to the treatment of these lesions is required, as surgery is required for refractory cases or those not amenable to embolization. Newer embolic agents, such as Onyx, hold significant promise for future therapy, yet long-term follow-up studies are required.

Endovascular management of spinal vascular malformations: history and literature review

Spinal vascular malformations represent a complex group of entities whose treatment paradigm continually evolves. Given the ever-increasing role of endovascular therapy, it is the goal of the authors to review the current literature regarding this therapeutic tool and to provide recommendations guiding management. A thorough literature search was conducted using Medline, with subsequent articles being identified through cross-referencing. The analysis revealed that, since its introduction in the 1960s, endovascular therapy has been used to manage the entire spectrum of spinal vascular malformations, during which period it has undergone considerable technological and technical evolution. As such, embolization has proved of growing therapeutic utility, largely resulting from the mounting evidence supporting its safety and efficacy, in addition to the inherent minimally invasive nature. This alternative to surgical intervention will be increasingly used as first-line therapy in spinal vascular malformations.

Selective arterial embolization with n-butyl cyanoacrylate in the treatment of aneursymal bone cyst of the thoracic vertebra: a case report

STUDY DESIGN

A case report of aneurysmal bone cyst of the mobile spine.

OBJECTIVE

To present a pediatric case of aneurysmal bone cyst (ABC) of the mobile spine treated successfully by selective arterial embolization (SAE) with n-butyl cyanoacrylate (NBCA).

SUMMARY OF BACKGROUND DATA

The endovascular treatment is an important treatment option for the ABC of the mobile spine. However, there are few reported case treated by SAE with NBCA.

METHODS

A 12-year-old healthy boy was introduced with a complaint of back pain. Computed tomography showed an osteolytic expanding mass in the pedicle, lamina, and spinous process on the level of T10. Magnetic resonance imaging revealed a multicystic mass with fluid-fluid levels that extended into the spinal canal and compressed the spinal cord from the dorsal side. Digital subtraction angiography showed an abnormal blood supply from the posterior spinal branch of the left T9 artery. An abnormal mass was diagnosed as an ABC based on these neuroradiologic examinations.

RESULT

The patient underwent SAE with NBCA (Histoacryl, B. Braun, Melsungen, Germany) diluted with Lipiodol (Laboratorie Guerbet, France) in a rate of 1:4. Computed tomography performed 1 month after treatment revealed partial ossification of the bone cortex. MR imaging showed shrinkage of the cyst and decompression of the spinal cord. Back pain of the patient disappeared and the shrunken cyst was stable without recurrence during the 3-year follow-up period.

CONCLUSION

SAE in a pediatric case with ABC of the mobile spine was effective in improving of clinical symptom and shrinking of the cyst.

Spinal cord vascular shunts: spinal cord vascular malformations and dural arteriovenous fistulas

Object

Spinal cord vascular malformations are rare, fascinating lesions. In this paper, the authors' goal was to demonstrate how these lesions, more specifically spinal cord arteriovenous malformations and dural arteriovenous fistulas, are assessed, classified, and managed at their institution. They also highlight some aspects of classification and management that may be different from the views of others.

Methods

The authors reviewed the 20-year experience at the senior author's institution regarding the management of spinal cord vascular malformations. They discuss the management, surgical and endovascular treatment results, and the classification that resulted from the combined experience of 3 major reference centers.

Results

The accumulated knowledge on embryological and pathophysiological aspects in such a rare disease resulted in a more global, patient-oriented (and not radiologically oriented) approach to spinal cord shunts.

Conclusions

The multiple classifications proposed for spinal cord vascular malformations reflect the continuous advancement of the authors' understanding. They adopt a classification based on new physiological and genetic data that treats these lesions as expressions of more complex disease processes and not simply a morphological target, with direct impact on therapeutic options.

Overview of the current role of endovascular and surgical treatment in spinal dural arteriovenous fistulas

Dural arteriovenous fistulas are the most common vascular malformations of the spinal cord. These benign vascular lesions are considered straightforward targets of surgical treatment and possibly endovascular embolization, but the outcome in these cases depends mainly on the extent of clinical dysfunction at the time of the diagnosis. A timely diagnosis is an equally important factor, with early treatment regardless of the type more likely to yield significant improvements in neurological functioning. The outcomes after surgical and endovascular treatment are similar if complete obliteration of the fistulous site is obtained. In the present study, the authors evaluated the current role of each modality in the management of these interesting lesions.

Spinal dural arteriovenous fistulas: clinical experience with endovascular treatment as a primary therapeutic modality

OBJECTIVE

The aim of this study was to evaluate the efficacy of endovascular therapy as a primary treatment for spinal dural arteriovenous fistula (DAVF).

METHODS

The authors reviewed 18 patients with spinal DAVFs for whom endovascular therapy was considered as an initial treatment at a single institute between 1993 and 2006. NBCA embolization was considered the primary treatment of choice, with surgery reserved for patients in whom endovascular treatment failed.

RESULTS

Surgery was performed as the primary treatment in one patient because the anterior spinal artery originated from the same arterial pedicle as the artery feeding the fistula. Embolization was used as the primary treatment modality in 17 patients, with an initial success rate of 82.4%. Two patients with incomplete embolization had to undergo surgery. One patient underwent multiple embolizations, which failed to completely occlude the fistula but relieved the patient's symptoms. Spinal DAVF recurred in two patients (one collateral development and one recanalization) during the follow-up period. The collateral development was obliterated by repeated embolization, but the patient with recanalization refused further treatment. The overall clinical status improved in 15 patients (83.3%) during the follow-up period.

CONCLUSION

Endovascular therapy can be successfully used as a primary treatment for the majority of patients with spinal DAVFs. Although it is difficult to perform in some patients, endovascular embolization should be the primary treatment of choice for spinal DAVF.

Long-term follow-up of craniovertebral junction arteriovenous fistulas surgically treated by feeder obliteration: report of three cases

Craniovertebral junction arteriovenous fistulas are still rare and are viewed differently from other arteriovenous fistulas because of their specificity of location and treatment. Intravascular treatment has come to play an important role in this area, but it is still controversial in terms of safety and reliability for complete obliteration. From the anatomical point of view, direct surgery seems to be more efficient and safe than endovascular therapy based on our experience with three surgically treated cases. In all three cases, the surgical approach was intended to obliterate the feeders in the vicinity of the nidus. In 2 of 3 cases, follow-up angiography showed complete obliteration of the fistulas and one case showed partial obliteration. No recurrence of symptoms was encountered 4-7 years postoperatively. Surgical treatment is still advantageous over intravascular treatment in this type of arteriovenous malformation. Simple surgical fistulous obliteration may lead to the gradual complete disappearance of this malformation.

Successful management of an anterior thoracic Type IV spinal arteriovenous malformation with two associated aneurysms utilizing vertebrectomy

Anteriorly located Type IV thoracic arteriovenous malformations (AVMs) are difficult to treat surgically. Although high-flow fistula subtypes are amenable to treatment using endovascular techniques, low-flow fistulas should be treated surgically. There are few reports discussing the diagnosis, behavior, and treatment of these spinal fistulas due to their low incidence. Posterior surgical approaches to Type IV spinal AVMs reported in the literature have been associated with high morbidity rates or aborted procedures. The authors report the successful management of a T-12 Type IV spinal AVM with an emphasis on approach, interoperative angiography, and the use of modern instrumentation. To the authors' knowledge, this is also the first reported case of multiple arterial-side aneurysms in a Type IV AVM of the anterior spinal artery.

Spinal dural arteriovenous fistulae: clinical features and long-term results

OBJECTIVE

The goals of this study were to characterize the clinical, radiological, treatment, and outcome data associated with patients diagnosed with spinal dural arteriovenous fistulae (SDAVFs) at a single tertiary care institution over a 20-year period.

METHODS

A 20-year retrospective study was undertaken at our university hospital. Patients with mixed intracranial and spinal dural fistulas were excluded. A literature review of articles reporting endovascular or combined treatment of SDAVFs was performed.

RESULTS

Between 1984 and 2005, our institution diagnosed and treated 63 patients (mean age, 62; 13 women, 50 men) with SDAVFs. The presenting symptoms were consistent with progressive myelopathy, and included lower extremity weakness (33 patients, 52%), parasthesias (19 patients, 30%), back pain (15 patients, 24%), and urinary symptoms (four patients, 6%). Thirty-nine patients underwent an initial endovascular embolization with 27 requiring only this first procedure for complete obliteration. On the other hand, 24 patients underwent an initial surgical procedure with 20 of them treated successfully with a single operation. Endovascular patients presented at mean age 62.3 years (standard deviation [SD], 10.6), were hospitalized for an average of 3.1 days (SD, 2.6), and were followed-up for 39 months (SD, 33). Surgical patients presented at mean age of 65.8 years (SD, 10.3), were hospitalized for 9.8 days (SD, 2.7), and were followed-up for 35 months (SD, 44). A significant improvement in Aminoff-Logue scores was found in both the endovascular and surgery groups (gait, P < 0.001; micturition, P = 0.005). The endovascular group had reduced hospitalization (P = 0.0001). No differences were found in the magnitude of clinical response to treatment.

CONCLUSION

SDAVFs most commonly present with progressive myelopathy, yet often remain undiagnosed for months or years. Endovascular therapies and surgical therapies are associated with significantly improved symptoms once the definitive diagnosis of SDAVF is made.

Recanalization and particle exclusion after embolization of uterine arteries in sheep: a long-term study

OBJECTIVE

To compare the long-term evolution of uterine arteries after embolization with the two most commonly used embolic agents for fibroid embolization: nonspherical polyvinyl alcohol (PVA) particles and trisacryl gelatin microspheres (TGMS).

DESIGN

Prospective study.

SETTING

University-based interventional radiology, pathology, and reproductive physiology units.

ANIMAL(S)

Two groups of 10 sheep embolized in the uterine artery.

INTERVENTION(S)

Embolization of the uterine artery with either 600-1000 microm nonspherical polyvinyl alcohol (PVA) particles or with 700-900 microm trisacryl gelatin microspheres (TGMS). Animals were synchronized and naturally inseminated. Animals were killed at 26 months.

MAIN OUTCOME MEASURE(S)

Uteri were examined pathologically for vessel size, site of occlusion, recanalization rate of vessels, and particle location within the vascular wall.

RESULT(S)

The PVA particles were more numerous in the vessels' lumen than the TGMS particles (13.3 +/- 20.8 vs. 2.5 +/- 2.7), were located more proximally than TGMS (97% vs. 68% in the trunk and first branches of the uterine artery), and were found almost exclusively in the intima (99.2%). In contrast, 54.4% of the TGMS particles were found in the intima, and 45.6% partially or totally excluded. The rate of recanalization was not statistically significantly different for PVA and TGMS (65.2% vs. 60.6%).

CONCLUSION(S)

The long-term evolution of uterine arteries was different after uterine artery embolization with PVA and TGMS because PVA particles formed large-sized aggregates that occluded proximal vessels and remained in the vessel intima. Microspheres occluded more distal vessels, and about 50% of them were partially or totally excluded from the vessel.

Long-term outcome of a multidisciplinary concept of spinal dural arteriovenous fistulae treatment

INTRODUCTION

The optimal treatment of spinal dural arteriovenous fistulae (SDAVF) remains controversial and long-term follow-up data, especially data from multidisciplinary treatment, are rarely available. Thus, long-term outcomes following a multidisciplinary approach to the treatment of SDAVF were investigated.

METHODS

The investigation included 26 patients with SDAVF treated at the authors' department over a 15-year period including a follow-up of more than 2 years. The treatment strategy when occlusion of the draining vein could be achieved was to embolize the fistula with Histoacryl, with surgery reserved for those patients unsuitable for embolization. Posttreatment angiography followed by MRI was performed in all patients. Clinical follow-up was performed using the gait and micturition Aminoff-Logue scale scores and the modified Rankin scale score.

RESULTS

Embolization was performed in 19 patients (73.1%), and direct surgery in 7 patients (26.9%). Follow-up angiography (at a mean of 21.7 months) showed occlusion of the SDAVF in 24 patients (92.3%). Of the 19 embolized patients, 2 (10.5%) developed recurrence secondary to insufficient occlusion of the SDAVF draining vein, and one of these two patients underwent re-embolization and one re-operation. No negative effects of SDAVF recurrence on the final clinical outcome were identified in either patient. MRI after angiography (at a mean of 91.5 months) demonstrated occlusion of all SDAVFs. After a mean clinical follow-up of 103.4 months there was a statistically significant improvement in both the modified Rankin scale score and the Aminoff-Logue gait scale score (P < 0.05).

CONCLUSION

The present multidisciplinary study showed for the first time that embolization leads to stable neuroradiological results and favourable clinical outcomes even for very long follow-up times of more than 100 months. Microsurgery remains the treatment of choice when safe embolization of the draining vein cannot be achieved.

Endovascular treatment of spinal cord arteriovenous malformations

Spinal cord arteriovenous malformations are rare lesions that represent one-tenth of the brain arteriovenous malformations. Depending on their location and relationship to the dura, these lesions are divided into four categories. Their clinical manifestations may vary from mild symptoms to severe motor deficits. Spinal angiography remains the "gold standard" for diagnosing spinal cord vascular lesions. Although the type of shunting remains difficult to determine by the magnetic resonance imaging, it is well analyzed by spinal angiography. The cure of the shunting is not by itself a therapeutic goal, but the objective is the creation of a new hemodynamic equilibrium between the lesion and the spinal cord to decrease the risk of hemorrhage and prevent the progression of the spinal cord ischemia. The endovascular tools seem to be a reasonable therapeutic option for the treatment of the majority of the spinal cord arteriovenous malformations.

Management of spinal dural arteriovenous fistulae with emphasis on an endovascular approach

Spinal arteriovenous shunts are rare and present at a rate of approximately 1:10 with cerebral arteriovenous shunts. Spinal dural arteriovenous fistulas (SDAVF) are the most common type of spinal vascular malformation in the adult and account for about 60% of all, with a marked male predominance (5:1). Endovascular treatment has gained force as the treatment of choice in recent years. We reviewed the patients sent to our service at Clinica del Rosario in Madrid and Hospital General de Cataluña in Barcelona between January 1991 and December 2005 with a diagnosis of SDAVF made clinically or by imaging for possible endovascular treatment. Location, presenting symptoms, and clinical outcome according to treatment were analyzed. A total of 104 patients were diagnosed and treated for a SDAVF, 85 were men and 19 women aged between 23 and 79 years (average 58). Seventy-six were treated with embolization alone (73%), 21 with a combination of endovascular therapy and surgery (20.1%) and seven patients had surgery alone (6.7%). Of the embolization group, 62 patients were cured (81.5%), 11 improved (14.4%) and three (3.9%) worsened. Of the group with combined therapy, 13 (61.9%) were cured, five (23.8%) improved and three (14.2%) worsened. Among the surgery group, four (57.2%) were cured and three (42.8%) worsened. Endovascular approach with liquid adhesive is gaining more acceptance as the treatment of choice for SDAVF if the conditions allow a super selective catheterization of the shunt. These patients benefit most when diagnosis is made early in the course of the pathology and have a better chance of a complete remission of symptoms.

Cervical dural arteriovenous fistula presenting with brainstem dysfunction: case report and review

STUDY DESIGN

We present a rare case of cervical dural arteriovenous fistula (C-DAVF) presenting with brainstem dysfunction. We discuss the details of the case and review previous articles on C-DAVF.

OBJECTIVES

Our case study illustrates the relation between uncommon neurologic findings and altered hemodynamics resulting from the anatomic features of the neural pathway. Based on a review of 31 cases of C-DAVFs published since 1990 (30 patients, including our own), we sought to determine which surgical treatment for C-DAVF, endovascular surgery, or direct interruption of the draining vein, is more effective.

SUMMARY OF THE BACKGROUND DATA

A combination of endovascular techniques and direct interruption procedures was successful in curing the C-DAVF in our patient. The selection between endovascular surgery and surgical interruption in the treatment of C-DAVF is controversial.

METHODS

We sought to identify the characteristics and surgical methods most closely associated with complete cure for C-DAVF. RESULTS.: According to the reports on 31 cases of C-DAVF treated surgically (including our own), 20 DAVFs were managed by open surgery with interruption, 8 were treated by endovascular surgery, and 3 underwent a combined open and endovascular approach. Twenty-one patients showed symptomatic improvement or stabilization without additional treatment during the postsurgical course. Surgical revisions were performed in 3 patients (10.0%) (including the present case), all of whom initially underwent endovascular surgery. None of the cases treated by surgical interruption of the draining vein showed signs of recurrence.

CONCLUSIONS

Surgical interruption of the draining vein is more effective than endovascular surgery in bringing about an absolute cure for C-DAVF. In exceptional cases, however, endovascular surgery is the preferred treatment. This is particularly so for elderly or medically compromised cases with contraindications against general anesthesia, as well as for moribund cases which, like our own case, present with rapidly deteriorating neurologic status on admission.

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.

Spinal dural arteriovenous fistula

PURPOSE OF REVIEW

To summarize clinical key points, diagnostic features, and results of imaging and therapy of spinal dural arteriovenous fistula (SDAVF).

RECENT FINDINGS

SDAVF accounts for 70% of spinal arteriovenous malformation with an annual incidence of 5-10 cases per million. At least 80% of patients are male, and more than 66% of patients are in the sixth and seventh decade of life indicating preponderance of gender and age. Thrombophilia is not a predisposing factor of disease. Clinical course is predominated by symptoms of congestive myelopathy, but subarachnoid hemorrhage may occur. Double SDAVF is a rare problem in the management of disease. Magnetic resonance imaging has replaced myelography as screening procedure. Contrast-enhanced magnetic resonance angiography and multislice computerized tomographic angiography may facilitate diagnostic procedure, however, spinal angiography is still required to confirm diagnosis. Treatment by permanent occlusion of fistula results in clinical improvement in 70% of cases. Microsurgical shunt interruption has proven secure and reliable. Endovascular shunt embolization has been established as a standardized procedure, but occlusion rates are still lower than in surgical treatment.

SUMMARY

Advances have been made in diagnosis and treatment of SDAVF, but the disease is still not completely understood.

Early Disappearance of Cord Signal Changes Following Endovascular Treatment of a Spinal Dural AV Fistula

SUMMARY

Spinal dural arterio venous fistulas (SDAVFs) are the commonest type of spinal vascular malformations and are encountered mostly among adult patients. Magnetic Resonance Imaging (MRI) in patients with SDAVFs demonstrates features like spinal cord swelling and signal changes. Cord signal changes are believed to be due to venous stasis.Treatment of a spinal vascular malformation may result in complete or partial resolution of MR findings with associated clinical improvement. The earliest documentation of reduction or disappearance of cord signal changes on post treatment MR images, was one month later in one series in the literature.We present and discuss disappearance of cord signal changes on MRI within 72 hours following endovascular treatment by liquid glue injection in a patient with SDAVF.

Treatment of Spinal Cord Perimedullary Arteriovenous Fistula: Embolization versus Surgery

OBJECTIVE

To provide the optimal treatment strategy for perimedullary arteriovenous fistula (PMAVF).

METHODS

Nineteen patients with PMAVF (Type IVa in 9 patients, Type IVb in 6, and Type IVc in 4) were treated at Seoul National University Hospital between January 1988 and March 2001. Their mean age was 28 years (range, 6-52 yr), and the male-to-female ratio was 1.7:1. The mean follow-up period was 20 months (range, 2-55 mo). Most patients presented with symptoms of slowly progressive myelopathy (13 patients). On spinal angiography, all but 2 showed fistula at the level of the conus medullaris. The feeder was the anterior spinal artery and/or the posterior spinal artery in 14 patients and the posterior spinal artery in 5. All patients underwent endovascular or surgical treatment.

RESULTS

With endovascular treatment (11 patients; IVa, n = 5; IVb, n = 2; IVc, n = 4), complete angiographic obliteration of fistula was performed in 5 and partial obliteration in 4 (IVa, n = 1; IVb, n = 2; IVc, n = 1). Symptomatic improvement or arrest of progression was achieved in 5 of 9 patients with complete or partial occlusion. Embolization failed in two (IVa, n = 1; IVc, n = 1). With surgery (10 patients [IVa, n = 6; IVb, n = 4], including 2 patients with partial or failed embolization), most (9 of 10) were improved or stable.

CONCLUSION

Good results were achieved with surgery for Types IVa and IVb PMAVF located at the level of the conus medullaris. For Type IVc PMAVF, a fistula located on the ventral side of the spinal cord or above the conus medullaris, endovascular treatment might be considered. Because of rapidly evolving endovascular techniques, however, further studies are warranted.

Excision of high and mid cervical spinal cord arteriovenous malformations by anterior operation

Symptomatic cervical spinal arteriovenous malformations (AVMs) located on the anterior aspect of the spinal cord are rare and surgical removal of these AVMs presents considerable challenges and risks. Surgical techniques to date have usually been by posterior approach and lateral dissection around the cord or via midline myelotomy, both approaches involving cord manipulation and retraction and in the latter, dissection through the spinal cord. We present two teenage patients with symptomatic anteriorly placed mid to high cervical spinal AVMs and associated aneurysm in which excision of the AVMs and aneurysm was performed by an anterior approach using vertebrectomy/corpectomy. The first case had a small perimedullary glomus-type AVM with an aneurysm on the anterior aspect of the cord at the C3/4 level; excision was performed using a single level vertebrectomy/corpectomy, the patient remaining neurologically intact. The second case had a medium-sized juvenile AVM with an aneurysm, both perimedullary and intramedullary, centred at the C5/6 level; excision was performed using a two-level vertebrectomy/corpectomy with no deterioration in the marked pre-operative tetraparesis, which at long-term follow up had improved and stabilised. Anterior approaches have been recently described for treatment of anteriorly placed cervical arteriovenous fistulas (AVFs) and an intramedullary haemangioblastoma, but not as yet for spinal AVMs. These are the first two reported cases of anteriorly situated cervical AVMs successfully removed surgically by an anterior approach and with good neurological outcomes.