Spinal dural arteriovenous fistulas: long-term follow-up of 44 treated patients

Recurrence Rates Following Treatment of Spinal Vascular Malformations: A Systematic Review and Meta-Analysis

BACKGROUND

Spinal vascular malformations (SVMs), including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), are a varied group of vascular lesions that can be subclassified according to localization, vascular structure, and hemodynamics. Early intervention is necessary to halt progression of disease and minimize irreversible dysfunction. We sought to characterize initial treatment success and recurrence rates following interventional treatment of various types of SVMs.

METHODS

A systematic review and meta-analysis were performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. SVMs were categorized into 4 groups: dural AVFs, perimedullary AVFs, intramedullary AVMs, and extradural-intradural AVMs (e.g., epidural, paraspinal). Initial occlusion, recurrence, and complication rates were compared using random-effects analysis.

RESULTS

There were 112 manuscripts included, with a total of 5626 patients with SVM. For treatment, 2735 patients underwent endovascular embolization, 2854 underwent surgical resection, and 37 underwent stereotactic radiosurgery. The initial treatment success and overall recurrence rates following surgical resection of all SVMs were 89.5% (95% CI: 80.5%-98.5%) and 2.3% (95% CI: 0.9%-3.7%), respectively. Those rates following endovascular embolization were 55.9% (95% CI: 30.3%-81.5%) and 27.7% (95% CI: 11.2%-44.2%), respectively. Higher rates of initial treatment success and lower rates of recurrence with surgery were observed in all subtypes compared to embolization. Overall complication rates were higher after embolization for each of the SVM categories.

CONCLUSIONS

Surgical resection of SVMs provided higher rates of initial complete occlusion and lower rates of recurrence than endovascular techniques. Attaining technical success through obliteration must still be weighed against clinical impact and natural history of the specific vascular malformation.

Acute Myelopathy: Vascular and Infectious Diseases

Vascular and infectious causes are rare but important causes of spinal cord injury. High suspicion for these processes is necessary, as symptoms may progress over hours to days, resulting in delayed presentation and diagnosis and worse outcomes. History and clinical examination findings can assist with localization of the affected vascular territory and spinal level, which will assist with focusing spinal imaging. Open and/or endovascular surgical management depends on the associated vascular abnormality. Infectious myelopathy treatment consists of targeted antimicrobial therapy when possible, infectious source control, and again, close monitoring for systemic complications.

Back Pain in Rare Diseases: A Comparison of Neck and Back Pain between Spinal Cord Ischemia and Spinal Dural Arteriovenous Fistula

Neck and back pain may be noted like a first symptom in rare diseases: spinal cord ischemia and spinal dural arteriovenous fistula (SDAVF). Spinal cord ischemia is a rarer pathology, compared with cerebral ischemia, yet the morbidity and mortality are comparable in both cases; furthermore, classifying the acute loss of function in the spine, encountered in spinal cord ischemia as an important neurological entity. SDAVF presents the same clinical symptoms as spinal cord ischemia, but even though it has a progressive character, the impact in the quality of patients’ lives being equally as important. Between August 2012–August 2017 we admitted through the hospital emergency department 21 patients with spinal cord ischemia and 11 patients with SDAVF (only self-casuistry). Demographic (age, gender), clinical, imagistic (Magnetic Resonance Angiography, Magnetic Resonance Imaging), paraclinical data as well as history, time to diagnosis, the visual analogue scale for pain (VAS score), risk factors, surgical and medical treatment, evolution, neurorehabilitation, were all used to compare the two lots of patients. The aim of this study was to observe potential differences in the demographics, symptomatology, VAS scores and treatment in comparison for spinal cord ischemia and SDAVF, to facilitate the further recognition and management in these diseases. In group A we have 21 patients with spinal cord ischemia (14 females, 7 males). The median age was 41.3 years (range 19–64). The median time to diagnosis was 7 h. The most frequent symptoms were acute neck or back pain at onset (100%), motor deficits (95.24%), sensory loss (85.72%), and sphincters problems (90.48%). The most common location was the lumbosacral spine (14 cases; 66.67%; p-value = 0.03) for spinal cord ischemia and the thoracic spine (7 cases, 63.64%; p-value = 0.065) for SDAVF. The treatment of spinal cord ischemia was medical. In group B we included 11 patients (6 females, 5 males). The median age was 52.6 years (range 28–74). The median time to diagnosis was 3 months (range 2 days–14 months). Patients have progressive symptoms: neck or back pain (100%), gait disturbances (100%) and abnormalities of micturition (100%). The treatment of SDAVF was surgical occlusion of fistula. The proportion of severe VAS score (7–10) in patients with spinal cord ischemia was significantly higher than that in patients with SDAVF (100% vs. 18, 19%; p-value = 0.051). Taking into consideration that the usual findings and diagnosis of spinal cord ischemia and SDAVF are still challenging for neurologists and in some cases the difficulties are related to technical limitations, we consider these entities to be rare but very important for the life of our patients. Patients were grouped into spinal cord ischemia and SDAVF status and those with acute or chronic pain conditions, measured by the VAS score. Patients with spinal cord ischemia develop acute neurological symptoms. They are much younger than the patients with SDAVF and the recovery rate is higher. Patients with SDAVF develop a progressive myelopathy and they suffer considerable neurological deficits. Imaging the lesions with MR angiography or MRI, we can confirm the diagnosis.

Long-term surgical outcomes of patients with delayed diagnosis of spinal dural arteriovenous fistula

Spinal dural arteriovenous fistula (dAVF) is an extremely rare vascular entity that is usually misdiagnosed. We sought to determine the long-term clinical outcomes of patients undergoing microsurgical treatment for delayed diagnosis of spinal dAVF. This retrospective study identified patients with delayed diagnosed spinal dAVF at our institution from 2009 to 2018. Patients' data, including demographics, imaging, and follow-up data, were evaluated. This cohort included 65 consecutive patients with 68 dAVFs and a male-to-female ratio of 4:1 and a mean age of 53.5 ± 13.7 years. The presenting symptoms consisted of limb weakness (n = 42, 64.6%), paraparesis (n = 34, 52.3%), sphincter disturbances (n = 8, 12.3%), and pain (n = 13, 20.0%). The proportion of patients with each symptom significantly increased and patients experienced increased disability when the diagnosis was finalized. The mean length of delay of diagnosis was 20.7 ± 30.0 months. Surgery resulted in complete occlusion of the fistula on the first attempt in all patients. Three patients developed recurrent fistulas, and three died in the follow-up period. Improved motor function was achieved in 38 patients (59.5%). Other symptoms, such as sensory disorders, sphincter dysfunction, and pain, improved by 37.3%, 32.3%, and 66.7%, respectively. Patients with spinal dAVF usually exhibit progressive ascending myelopathy and often remain misdiagnosed for months to years. Some patients' increased disability cannot be reversed through surgery.

Vascular Disorders of the Spinal Cord

PURPOSE OF REVIEW

Prompt recognition and timely management of vascular disorders of the spinal cord can improve patient outcomes. This article provides contemporary and practical knowledge about the most common vascular myelopathies.

RECENT FINDINGS

New studies have provided additional information on the risk factors and impact of neurologic monitoring on perioperative spinal cord infarction. Additionally, recent publications have provided information on the impact of misdiagnosis, corticosteroid treatment, and postoperative prognosis in the treatment of spinal dural arteriovenous fistulas and have discussed the outcome of patients with spinal arteriovenous malformations treated with embolization, surgery, and stereotactic radiosurgery. Finally, recent studies have provided information on the natural history and postoperative prognosis of spinal cavernous malformations and on the risk factors and surgical outcome of patients with spinal epidural hematomas.

SUMMARY

Diagnostic and therapeutic challenges are inherent in managing patients with vascular disorders of the spinal cord, and clinicians should have a thorough understanding of these disorders to facilitate optimal outcomes for patients with these potentially devastating illnesses. This article begins by reviewing functional vascular anatomy and subsequently describes the fundamental characteristics of both ischemic and hemorrhagic vascular myelopathies to equip clinicians with the knowledge to avoid common pitfalls.

Malignant Melanotic Schwannian Tumor Presenting with Spinal Cord Infarction Due to Occlusion of the Artery of Adamkiewicz: Case Report and Review of the Literature

BACKGROUND

Malignant melanotic schwannian tumors (MMSTs) are rare peripheral nerve sheath tumors that typically exhibit benign clinical presentation and histopathology but malignant long-term behavior.

CASE DESCRIPTION

We report a case of a 22-year-old male with a T9-11 MMST who presented with acute paraplegia and complete loss of sacral function. Despite emergent decompression, he did not recover motor, sensory or bladder function, although bowel function did normalize.

CONCLUSIONS

The anatomic location and rapid presentation of permanent deficits are suggestive of infarction of the spinal cord supplied by the artery of Adamkiewicz, a rare presentation of this disorder and of spinal schwannomas in general.

Endovascular management of spinal dural arteriovenous fistulas

Spinal dural arteriovenous fistulas (dAVF) are the most common subset of the larger group of spinal vascular malformations. In this chapter, we discuss the definition, epidemiology, clinical presentation, diagnosis, treatment, and outcomes of spinal dAVF. Special attention is given to clinical approach, imaging, and diagnosis with discussion of newer spinal magnetic resonance angiographic techniques. Endovascular management techniques are discussed, including technical and safety considerations for the performance of spinal angiography and various methods of embolization. Embolization media, including liquid embolics, particles, and coils, are introduced. Finally, clinical and imaging outcomes are discussed with attention to the clinical and imaging findings of dAVF recurrence.

Clinical Characteristics and Treatment Outcomes of Spinal Arteriovenous Malformations

PURPOSE

Spinal arteriovenous malformations (SAVMs) are rare events. This study evaluated initial clinical presentations and treatment outcomes of SAVMs.

METHODS

In this study, 91 consecutive patients with SAVM between January 1993 and November 2014 were evaluated. Initial clinical presentations, radiological findings, treatment results, and follow-up outcomes were evaluated according to disease type and treatment modalities. Patient status was scored using the modified Rankin scale (mRS) and Aminoff-Logue Disability scale (ALS).

RESULTS

Of the SAVM patients 69 % were male and 31 % were female with a mean age of 49 years (range 11-82 years). At the time of initial imaging evaluation, myelopathy was the most common finding with main complaints of gait disturbance (69 out of 91, 76 %), sensory disturbances (61/91, 67 %), and bowel or bladder symptoms (51/91, 56 %). Among the 80 patients who received treatment 56 (62 %) underwent endovascular embolization and 24 (26 %) underwent surgery. Complete obliteration was achieved in 47 patients (84 %) after endovascular embolization and in 18 (75 %) after surgical ligation. At the time of final follow-up 67 patients (84 %) showed improvement of more than 1 point on the mRS, while 69 (86 %) showed significant improvement on the ALS after treatment.

CONCLUSION

The SAVMs presented with diverse neurological deficits, including myelopathy. Endovascular or surgical treatment of SAVMs can result in good clinical outcomes in most patients.

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.

Spinal dural arteriovenous fistula presenting with paraplegia following lumbar puncture

Spinal dural arteriovenous fistulas are rare lesions with an annual incidence of 1 per 100,000 population. In patients with this disease, an abnormal vascular dural shunt exists between a dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Generally, patients present with progressive paraparesis, urinary disturbances, and gait ataxia. In this report the authors describe a 61-year-old woman with a spinal dural arteriovenous fistula who developed an acute paraplegia after a nontraumatic lumbar puncture. The possible underlying mechanisms and treatment options are discussed.

Prognostic value of clinical and radiological signs in the postoperative outcome of spinal dural arteriovenous fistula

STUDY DESIGN

Retrospective consecutive case series.

OBJECTIVE

To determine predictors of outcome in patients undergoing surgical treatment of spinal dural arteriovenous fistula (SDAVF).

SUMMARY OF BACKGROUND DATA

Most previous studies assessing postoperative outcome in patients with SDAVF have been limited due to small population size, lack of sufficient information on presurgical variables, or short time of postoperative follow-up. Consequently, the most reliable predictors of functional outcome after treatment of SDAVF are not yet well established.

METHODS

Retrospective analysis of consecutive patients with SDAVF treated surgically between June 1985 and March 2008 in our institution. The Aminoff-Logue gait (G) and micturition (M) scores were used to stratify the degree of disability and the G + M score was used as the primary outcome measure. Demographics, clinical presentation, time to diagnosis, fistula level, presurgical motor and sphincter impairment, and magnetic resonance imaging findings were assessed as prognosticators for postoperative outcomes.

RESULTS

One hundred fifty-three patients were analyzed. Mean follow-up was 31 ± 36.2 months. Most patients were improved (44%) or stable (34%) upon the last follow-up. Among preoperative variables, worsening weakness with exertion was associated with a better G + M score at the last follow-up (P < 0.001) and presence of pinprick level was associated with a worse G + M score at the last follow-up (P = 0.020). On multivariable analysis, worsening weakness with exertion was associated with better outcome at the last follow-up, and higher G score at presentation and higher G + M score at discharge were associated with worse outcome at the last follow-up. Magnetic resonance images obtained postoperatively for 104 patients (mean, 19.1 ± 22.5 mo) showed complete resolution or improvement of the presurgical T2 signal abnormalities in 83.6% of cases. Changes in postoperative magnetic resonance image and fistula level did not correlate with functional outcomes.

CONCLUSION

The degree of preoperative disability from SDAFV does not determine who will benefit most from surgery and even patients with severe deficits can improve after treatment. Patients with preoperative exertional claudication and without pinprick level on examination have greater chances of postsurgical improvement.

LEVEL OF EVIDENCE

4.

Correlation between time to diagnosis and rehabilitation outcomes in patients with spinal dural arteriovenous fistula

BACKGROUND

Spinal dural arteriovenous fistulas (SDAVFs) are the most common spinal vascular malformations and can be a significant cause of myelopathy although they are under diagnosed. Surgical or embolization treatment of SDAVFs improved significantly in the last decade. However, a high percentage of patients are still left with severe disability.

OBJECTIVE

To describe the correlation between time to diagnosis and the rehabilitation outcomes of eight patients with SDAVFs.

DESIGN

Retrospective chart study of all SDAVF patients in 20 years.

SETTING

A tertiary university rehabilitation center.

MAIN OUTCOME MEASURES

The lower extremities motor score (LEMS), Functional Independence Measure (FIM), Spinal Cord Independence Measure (SCIM) and Walking Scale for Spinal Cord Injury (WISC II). Overall prognosis was evaluated using the Aminoff-Logue scale (ALS).

RESULTS

There were seven men and one woman with mean age of 61.3 ± 15 (30-72) and mean time until the diagnosis of SDAVF of 265.5 ± 245 days (4-730). At the end of rehabilitation period, five of the eight patients remained wheelchair dependent. Strong correlation was found between LEMS, FIM, SCIM, and WISC II scores and the functional level according to the ALS scale. A significant correlation was found between time to diagnosis and the height of the SDAVF, the clinical and rehabilitation outcomes. Patients with high SDAVF which were diagnosed late had the poorest prognosis.

CONCLUSIONS

The potential for functional ambulation in patients with SDAVF is related to the time of intervention. This finding emphasizes the important of early diagnosis and early intervention in SDAVF.

Spinal dural arteriovenous fistulas: clinical experience with endovascular treatment as a primary therapy at 2 academic referral centers

BACKGROUND AND PURPOSE

Spinal dural arteriovenous fistulas are a rare entity that, if left untreated, can lead to considerable morbidity with progressive spinal cord symptoms. The aim of this study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas that were primarily treated with endovascular embolization.

MATERIALS AND METHODS

A retrospective review was performed of all patients from 1997-2010 who underwent treatment at 2 academic referral centers for a spinal dural arteriovenous fistula. Follow-up was performed by clinical examination, and functional status was measured by use of the Aminoff-Logue Disability Scale, McCormick classification grading, and mRS scores. The nonparametric Wilcoxon signed rank test was used to compare pretreatment and posttreatment Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and mRS scores. P values < .05 were considered significant.

RESULTS

A total of 38 patients were included. Five patients (2 endovascular, 3 surgical) were lost to follow-up and therefore were excluded from the analysis, 29 patients were initially treated from an endovascular approach (9 Onyx, 20 cyanoacrylate), and 4 patients were treated from a standard surgical approach. Five patients in the endovascular group subsequently underwent surgery for various reasons. The clinical improvements in the Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and the mRS scores were statistically significant (P < .05, Wilcoxon signed rank test).

CONCLUSIONS

We conclude that endovascular treatment of spinal dural arteriovenous fistulas can result in good clinical outcomes. Surgery remains the treatment of choice when safe embolization of the proximal radicular draining vein cannot be obtained or because the shunting artery of the spinal dural arteriovenous fistula also supplies the anterior spinal, posterior spinal, or a radiculomedullary artery.

Spinal dural fistulas without swelling and edema of the cord as incidental findings

SUMMARY

SDAVFs cause hypertension and hence outflow obstruction in the perimedullary venous system resulting in swelling and edema of the cord followed by dysfunction. Clinical presentation is usually with gradual progressive paraparesis, numbness, and sphincter problems. MR imaging typically demonstrates the dilated perimedullary veins and the swelling and edema of the cord. During the past few years, we incidentally found an SDAVF on MR imaging with dilated perimedullary veins but without swelling and edema of the cord in 5 patients with unrelated presenting clinical symptoms. Spinal angiography confirmed the presence of an SDAVF in all 5 patients. Although the indication was considered questionable, eventually all 5 fistulas were endovascularly or surgically treated, resulting in normalization of the MR images.

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.

Comparison of rehabilitation outcomes following vascular-related and traumatic spinal cord injury

BACKGROUND

Previous studies have noted similar outcomes between vascular-related spinal cord injury (VR-SCI) and those with traumatic SCI (T-SCI), despite significant difference in their demographics and clinical presentation (age, level of injury (LOI), and degree of incompleteness).

OBJECTIVES

To review demographic and clinical presentation of VR-SCI and to compare outcomes with a matched group with T-SCI. Design Analysis of 10-year prospective data collection including 30 consecutive patients admitted to an SCI rehabilitation unit with VR-SCI and comparison with 573 patients with T-SCI. Outcomes were further analyzed comparing VR-SCI to T-SCI (n=30), matched for age, LOI, and ASIA (American Spinal Injury Association) Impairment Scale (AIS).

SETTING

A level 1 tertiary university trauma center.

MAIN OUTCOME MEASURES

Functional independence measure (FIM) score changes from admission to discharge. Secondary outcome measures included admission and discharge FIM scores, FIM efficiency, rehabilitation length of stay (LOS), and discharge disposition.

RESULTS

Overall, individuals with VR-SCI were more likely (P<0.0001) to be older (mean age 57.2 vs. 40.0 years) and have paraplegia (87 vs. 48%) than those with T-SCI. Common etiologies for VR-SCI were post-surgical complication (43%), arteriovenous malformation (17%), aortic dissection (13%), and systemic hypotension (13%). Common region of injury and AIS classification in VR-SCI was thoracic (73%) and AIS C (33%). Common SCI-related complications in VR-SCI included neurogenic bowel/bladder (93%), urinary tract infection (73%), pain (67%), pressure ulcers (47%), and spasticity (20%). Matched-group outcome comparisons did not reveal significant differences in FIM change, FIM efficiency, LOS, or disposition between VR-SCI and T-SCI.

CONCLUSION

VR-SCI leads to significant disability and is associated with common secondary SCI complications as well as medical co-morbidities. This study notes differing demographic and injury characteristics between VR-SCI and T-SCI groups. However, when matched for these differences, rehabilitation functional outcomes were not significantly different between the two groups.

Evaluation of angiographically occult spinal dural arteriovenous fistulae with surgical microscope-integrated intraoperative near-infrared indocyanine green angiography: report of 3 cases

BACKGROUND

Spinal dural arteriovenous fistulae (dAVFs), are lesions involving an aberrant connection between a radicular feeding artery and the venous system of the spinal cord at the dural sleeve of the nerve root. When rare dAVFs are occult on digitally subtracted catheter-based angiography, they present a diagnostic and therapeutic challenge.

OBJECTIVE

We report 3 cases of angiographically occult spinal dAVFs that were evaluated during surgery with indocyanine green (ICG) fluorescent microscope-integrated angiography.

METHODS

Three patients with clinical and magnetic resonance imaging features suggestive of a spinal dAVF but no abnormality on digital subtraction angiography underwent surgical exploration with the aid of microscope-integrated ICG videoangiography.

RESULTS

In all 3 cases, ICG identified the intradural vein draining the fistula, clearly distinguishing it from an artery or uninvolved medullary vein.

CONCLUSION

ICG angiography can rapidly identify a draining vein as it enters the spinal canal even in dAVFs not identifiable on catheter-based digital subtraction angiography.

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.

Long-term outcome in the repair of spinal cord perimedullary arteriovenous fistulas

BACKGROUND AND PURPOSE

The natural history of PMAVFs, also known as type IV spinal cord AVFs, is incompletely understood. Both open surgical and endovascular approaches have been described as treatment modalities for this disease. The goal of this study was to evaluate the long-term outcome of patients with PMAVFs treated at a single tertiary care institution.

MATERIALS AND METHODS

We conducted a retrospective study of 32 patients with PMAVFs, evaluated between 1983 and 2009. Data were gathered by reviewing outpatient clinic notes, operative and radiologic reports, and spinal angiograms. The PMAVFs were categorized into 1 of 3 types based on the angiographic imaging criteria. Pretreatment and posttreatment ambulation and micturition symptoms were quantified by using the ALS.

RESULTS

Thirty patients underwent corrective procedures, 4 by embolization alone, 11 by surgery alone, and 15 with a combination of the 2. Twenty-eight patients underwent follow-up spinal angiography, with residual shunt noted in 6 patients. The mean follow-up period was 54 months (range, 1-228 months). Analysis of the ALS scores revealed that treatment of PMAVFs, independent of technique, resulted in significant improvement in ambulation but inconsistent changes in micturition. In addition, residual fistula at the time of the follow-up angiogram was associated with worsened neurologic status or lack of improvement. Outcome analysis based on fistula type showed dramatic improvement in ALS ambulation scores (62%) for type 3 fistulas, compared with types 1 and 2 (26% and 27%, respectively).

CONCLUSIONS

Significant improvement in ambulation but in not micturition was observed following treatment. Residual fistula on follow-up angiography was associated with progressive worsening or lack of improvement in neurologic function. Patients with type 3 fistulas were shown to benefit most from treatment, with marked improvement in posttreatment ambulation scores. As endovascular and surgical techniques continue to evolve, further studies are warranted.

Indocyanine green video-angiography as an aid to surgical treatment of spinal dural arteriovenous fistulae

PURPOSE

To illustrate the use of indocyanine green (ICG) video-angiography to confirm abolition of spinal dural arteriovenous fistula (SDAVF) and preserve the normal vascular anatomy intraoperatively.

METHODS

A 73-year-old woman presenting with progressive myelopathy was diagnosed with an SDAVF, where the origin of the fistula was in close proximity to the origin of the posterior spinal artery. ICG was injected intravenously. Using a filter on the microscope, dynamic filling of the abnormal vasculature was visualised.

RESULTS

After applying a clip to the fistulous connection, we were able to see the successful interruption of the dural fistula, on-table in real time.

CONCLUSION

ICG video angiography confirmed interruption of the fistula and preservation of the associated posterior spinal artery. We find the application of this relatively new technology has the potential to shorten operating times, gives additional reassurance of completeness of surgical treatment and preservation of normal spinal vasculature.

Recovery from paraplegia after the treatment of spinal dural arteriovenous fistula: case report and review of the literature

BACKGROUND

Spinal dural arteriovenous fistula (SDAVF) is a rare and enigmatic disease. Functional outcome is particularly uncertain for the small group of patients that are unable to stand at the time of diagnosis (grade 5 gait disturbance on the Aminoff-Logue scale, ALS). The objective of this study is to examine the final functional outcome of patients with SDAVF in grade 5 gait ALS before treatment.

METHODS

We conducted a PubMed search using the keyword "spinal dural arteriovenous fistula." A review of the clinical series and single well-detailed case reports of SDAVF gathered 106 patients with grade 5 gait ALS on the initial examination. Additionally, we report the case of a 56-year-old man presenting acute paraplegia and urinary retention on admission who had complained of sporadic motor and sphincter disturbances for 1 year. Spine T2-weighted MR imaging showed a central hyperintensity within the spinal cord, and the angiography demonstrated a T-11 SDAVF. Interruption of the fistula was performed through an urgent one-level laminectomy.

RESULTS

Grade 5 gait ALS was present in 25% of the patients with SDAVF included in the clinical series. Latest follow-up showed that gait disturbance improved in 73% of patients after treatment, although less than 6% became grade 1 gait ALS. Micturition disturbances improved in 39%. Exploration of our patient showed improvement to grade 1 gait ALS 1 year after the surgical treatment.

CONCLUSION

Interruption of SDAVF in paraplegic patients may improve the final functional gait outcome in some cases. No complete recovery (grade 0 gait ALS) was achieved after treatment. Micturition disturbances had a worse prognosis than motor deficits.

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.

Spinal dural arteriovenous fistulas

Spinal dural arteriovenous (AV) fistulas are the most commonly encountered vascular malformation of the spinal cord and a treatable cause for progressive para- or tetraplegia. They most commonly affect elderly men and are classically found in the thoracolumbar region. The AV shunt is located inside the dura mater close to the spinal nerve root where the arterial blood from a radiculomeningeal artery enters a radicular vein. The increase in spinal venous pressure leads to decreased drainage of normal spinal veins, venous congestion, and the clinical findings of progressive myelopathy. On MR imaging, the combination of cord edema, perimedullary dilated vessels, and cord enhancement is characteristic. Therapy has to be aimed at occluding the shunting zone, either by superselective embolization with a liquid embolic agent or by a neurosurgical approach. Following occlusion of the fistula, the progression of the disease can be stopped and improvement of symptoms is typically observed.

Curable cause of paraplegia: spinal dural arteriovenous fistulae

BACKGROUND AND PURPOSE

The rarity of spinal dural arteriovenous fistulae makes physicians often overlook this potential diagnosis in patients with progressive gait disturbance and paraparesis. Consequently, patients with spinal dural arteriovenous fistulae can gradually become completely paraplegic if the final diagnosis is delayed considerably. The objective of the current study is to demonstrate that, particularly in patients with paraplegia, surgical treatment of fistula is necessary and often has a favorable outcome.

METHODS

Of 42 patients with spinal dural arteriovenous fistulae treated in our institution (surgery or endovascular treatment), 6 were paraplegic preoperatively (Grade IV on the McCormick scale and Grade V on the Aminoff scale, Grade 5 of modified Rankin Scale with motor ASIA between 0 and 10 for both lower limbs). Their clinical history revealed that paraplegia appeared progressively within a period of <3 months. All patients were clinically evaluated at 6 weeks, 6 months, and then annually during an average follow-up of 3 years. Patients received at least one spinal angiography and MRI test during the follow-up period.

RESULTS

Total exclusion of the fistula was performed surgically in all cases and was confirmed by spinal angiography. No surgical complications were recorded. All patients improved postoperatively. Three patients showed almost normal walking (Grade I on the McCormick scale, I on the Aminoff scale, Grade 1 of modified Rankin Scale) and 3 were able to walk with a cane (Grade II on McCormick, Grade III on Aminoff scale, Grade 2 of modified Rankin Scale). MRI tests were normal in all patients.

CONCLUSIONS

Our results indicate that treatment of fistula is a necessary intervention, even in patients with complete paraplegia.

Endovascular and surgical treatment of spinal dural arteriovenous fistulas

INTRODUCTION

The aim of this retrospective study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas (SDAVFs) that were treated with surgery, catheter embolization, or surgery after incomplete embolization.

METHODS

The study included 21 consecutive patients with SDAVFs of the thoracic, lumbar, or sacral spine who were treated in our institution from 1994 to 2007. Thirteen patients were treated with catheter embolization alone. Four patients underwent hemilaminectomy and intradural interruption of the fistula. Four patients were treated by endovascular techniques followed by surgery. The clinical outcome was assessed using the modified Aminoff-Logue scale (ALS) for myelopathy and the modified Rankin scale (MRS) for general quality of life. Patient age ranged from 44 to 77 years (mean 64.7 years).

RESULTS

Surgical as well as endovascular treatment resulted in a significant improvement in ALS (-62.5% and -31.4%, respectively, p < 0.05) and a tendency toward improved MRS (-50% and -32%, respectively) scores. Patients that underwent surgery after endovascular treatment due to incomplete occlusion of the fistula showed only a tendency for improvement in the ALS score (-16.7%), whereas the MRS score was not affected.

CONCLUSION

We conclude that both endovascular and surgical treatment of SDAVFs resulted in a good and lasting clinical outcome in the majority of cases. In specific situations, when a secondary neurosurgical approach was required after endovascular treatment to achieve complete occlusion of the SDAVF, the clinical outcome was rather poor. The best first line treatment modality for each individual patient should be determined by an interdisciplinary team.

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.

[Spinal dural arteriovenous fistula with peri-medullary venous drainage: analysis of a series from a single centre and review of the literature]

INTRODUCTION

The optimal diagnosis and therapeutic managements of spinal dural arteriovenous fistulae, a rare disease, is discussed.

MATERIAL AND METHODS

We report a series of 10 patients seen in a 7-year period, treated by embolization.

RESULTS

There were 6 males and 4 females, with an average age of 58.4 years (range: 31 to 74 years). Diagnosis was made 2 days to 5 years (mean 15.3 months) after symptom onset with a high rate of incomplete or atypical clinical patterns (prolonged isolated sensory disorder, lumbo-sciatalgia, claudication, monoplegia), or sudden-onset deficit. In all cases, spinal MRI showed an intramedullary high-intensity signal on T2-weighted images but enlarged intradural vessels in only 70p.cent of cases. Angiography showed in all cases an arteriovenous fistula at the upper dorsal level (T1 to T7, 5 cases), lower dorsal (T8-T12, in 3 cases) and lumbar levels (2 cases). The fistula was successfully obliterated after initial embolization in 3 cases, but two (2 cases) or 3 procedures (2 cases) were sometimes required. The endovascular therapy failed in 3 cases.

CONCLUSION

In this series, the fistula was successfully obliterated in 70p.cent of patients. In the literature, fistula of 96.8p.cent to 97.9p.cent of patients were obliterated by surgery, which is a more invasive treatment. Embolization could be used as the first-line therapy, but incomplete obliteration requires rapid surgery. While the success of embolization is demonstrated, MRI and angiography must still be performed 6 months later.

The role of non-invasive computed tomography in patients with suspected dural fistulas with spinal drainage

OBJECTIVE

Accurate diagnosis and demonstration of the angioarchitecture and localization of a spinal dural arteriovenous fistula is of crucial importance before treatment. Selective spinal angiography (DSA) has been considered the standard technique, but is invasive, time-consuming, and may be falsely negative. This report evaluates the use of noninvasive vascular imaging (computed tomographic and magnetic resonance angiography [MRA]) in patients suspected to have a dural fistula with spinal drainage.

METHOD

Ten consecutive patients had DSA and multidetector computed tomographic angiography (MDCTA), eight also had MRA. Nine were men with an average age of 67 years. In nine patients, the diagnosis was confirmed at surgery or intravascular treatment. Eight were proven to have a spinal dural fistula. In two, the fistula was within the cervical cranial dura. In all patients, the venous drainage involved only the spinal venous plexus.

RESULTS

MDCTA identified the level of the feeding artery in nine patients. In two cases, selective DSA failed to show the abnormality found on MDCTA, but both were confirmed at surgery. MRA was diagnostic in a case in which the lesion was not accurately depicted by either MDCTA or DSA. MRA was less accurate than MDCTA in determining the level of the feeding artery.

CONCLUSION

MDCTA and MRA can direct and focus DSA. MDCTA gives additional useful three-dimensional bone detail and localization information for the surgeon. It may replace DSA if surgery is the planned treatment.

Factors that affect the surgical outcomes of spinal dural arteriovenous fistulas

BACKGROUND

Authors disclose the factors that affect the surgical outcome of the spinal dural AVFs from the retrospective analysis of 13 cases.

METHODS

Thirteen patients with spinal dural AVF underwent microsurgical treatments between 1990 and 2004 at the Department of Neurosurgery, Aso Iizuka Hospital. The mean age was 62 years, and the median time to diagnosis was 38 months (range, 4-120 months). There were 12 men and 1 woman. The clinical features were characterized by spastic paraparesis in all 13 patients and micturition problem in 11 patients. All 13 patients showed the longitudinal extension of the high T2 intramedullary signals in magnetic resonance (MR) image. The microsurgical obliterations of the spinal dural AVFs were performed for all 13 patients because the endovascular treatments were difficult or failed to obliterate the lesions.

RESULTS

The durations of the symptoms were not directly correlated to the preoperative neurological conditions and the postoperative outcomes. The patient's age and the preoperative severity of myelopathy affected the postoperative outcomes. The mode of the longitudinal extension of the high T2 intramedullary signals in MR image, rostral or caudal, did not show the statistical significance to the outcome. The poor outcomes were observed in elderly patients and patients with preoperative modified Rankin Scale 4 and 5. A case with multiple spinal dural AVFs is also presented.

CONCLUSION

The spinal AVFs are treatable lesions through microsurgery or embolization. The likelihood of favorable outcome was affected by the severity of deficits and the patient's age.

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.

Spinal dural arteriovenous fistulas--an underdiagnosed disease. A review of patients admitted to the spinal unit of a rehabilitation center

BACKGROUND

Spinal dural arteriovenous fistulas (SDAVF) are rare and present with non-specific symptoms. The diagnosis is difficult and it is therefore conceivable that patients may not be recognized.

METHODS

We reviewed the intake forms of patients who had been admitted to the spinal cord injury ward of a rehabilitation center in the period 1980-2004 to identify possible patients with an undiagnosed SDAVF. Clinical and radiological data were evaluated in selected cases.

RESULTS

In 20 of 1429 newly admitted patients to the rehabilitation center (in 614 of whom trauma was not the cause), we restudied the CT myelograms, MRI scans or spinal angiograms and in two of these we found an undiagnosed SDAVF, and one cerebral dural arteriovenous fistula. One of these three was diagnosed with SDAVF 8 years after the admission to the rehabilitation center; the other two patients had never been diagnosed with SDAVF. In 9 patients a diagnosis of SDAVF had already been established by the time they were admitted to the spinal cord unit. In 20 other patients the admission diagnosis was a vascular lesion or 'progressive myelopathy' but appropriate radiological studies had been destroyed or had never been performed.

CONCLUSION

Our results suggest that spinal dural arteriovenous fistulas are an underdiagnosed condition.

Embolization of spinal dural arteriovenous fistulas: importance of occlusion of the draining vein

OBJECT

The aim of this study was to assess whether glue-induced occlusion of the draining vein predicts permanent closure of the fistula following embolization of spinal dural arteriovenous fistulas (SDAVFs).

METHODS

Between 1994 and 2004, 36 consecutive patients with an SDAVF were treated at the authors' institution. Twelve patients underwent surgery and 24 glue-based embolization. In 12 of 24 embolization procedures the draining vein was occluded and no recurrence or persistent fistula was seen during the follow-up period. In the other 12 patients the glue had not reached the draining vein and in eight of these the fistula recurred, necessitating additional treatment.

CONCLUSIONS

In embolization of SDAVFs penetration of the glue into the draining vein predicts permanent closure of the fistula. When penetration of the glue into the draining vein can be expected, embolization is the preferred treatment option. In other cases surgery should be the treatment of choice.