Clinical presentation and treatment outcomes of spinal epidural arteriovenous fistulas

Clinical presentation and treatment of 26 spinal epidural arteriovenous fistulas: a single-center experience

BACKGROUND

Spinal epidural arteriovenous fistulas (SEDAVFs) are rarely diagnosed vascular malformations that can cause spinal cord compression and congestive myelopathy.

METHODS

This is a single-center, retrospective case series of patients with SEDAVFs who underwent observation or treatment at UCLA medical center between 1993 and 2023.

RESULTS

Between 1993 and 2023 a total of 26 patients at UCLA were found to have a SEDAVF. The median age at treatment was 59 years (range 4 months to 91 years). Compared with sacral, lumbar, and thoracic SEDAVFs, patients with cervical SEDAVF were younger (41 years vs 63 years, P=0.016) and more likely to be female (66.7% vs 14.3%, P=0.006). Possible triggers for development of SEDAVFs may be prior spinal surgery or trauma (n=4), turning the neck (n=1), lifting a heavy box (n=1), a prolonged period of bending over (n=1), and neurofibromatosis type 1 (n=1). Of the 22 patients treated endovascularly, 18 (82%) were angiographically cured on the first attempt without complications. One patient underwent surgical treatment alone and had a failed surgery on the first attempt, and developed a surgical site infection after the second successful attempt at treatment. Of the 16 patients with adequate clinical follow-up, 11 (69%) demonstrated early improved clinical outcome (eg, improved strength on examination, absent bruit).

CONCLUSIONS

SEDAVFs are a rarely diagnosed disease that can be treated effectively and safely with endovascular embolization in most cases. Patients with sacral, lumbar, and thoracic SEDAVFs were older and more often male compared to patients with cervical SEDAVFs.

Comparative outcomes of endovascular vs. surgical treatment in craniocervical junction dural arteriovenous fistulas: A systematic review and meta-analysis

BACKGROUND

Craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) are rare and complex vascular malformations that are challenging to diagnose and treat. This study aims to compare surgical and endovascular treatments for CCJ-DAVFs through a systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis was conducted according to the PRISMA guidelines. PubMed, Scopus, and Web of Science databases were searched from inception to July 2024.

RESULTS

Fifteen studies involving 266 patients were included. Of these, 143 (53.8 %) patients underwent surgical treatment alone and 123 (46.2 %) underwent endovascular treatment alone. In the surgical group, the complete obliteration rate at last follow-up was 89.8 %. Retreatment rate was 6.2 %. Periprocedural complications occurred in 21.6 % of cases. In the endovascular group, the complete occlusion rate at last follow-up was 73.6 %. Retreatment rate was 46.7 %. Periprocedural complications occurred in 18.8 % of cases. Comparative meta-analysis revealed that the rate of complete obliteration at last follow-up was significantly higher in the surgical group (OR: 0.24; CI: 0.07 to 0.89, p = 0.03). Surgical treatment had a significantly higher successful treatment rate (OR: 0.24; CI: 0.07 to 0.89, p = 0.03) and lower retreatment rate (OR: 37.13; CI: 6.31 to 218.59, p < 0.01). No significant differences were observed between the groups in terms of periprocedural complications or complete resolution of symptoms.

CONCLUSION

Surgical treatment for CCJ-DAVFs achieves higher rates of complete obliteration with lower retreatment rates compared to endovascular treatment. However, endovascular treatment showed a tendency towards reducing periprocedural complications while increasing the likelihood of complete resolution of symptoms. Individualized treatment plans for CCJ-DAVFs, should be considered according to their anatomical location and potential surgical accessibility. Further studies are required to confirm these findings.

Dural arteriovenous fistulas at the craniocervical junction: a systematic review and meta-analysis

BACKGROUND

The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management.

METHODS

Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes.

RESULTS

We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2-64.5), 58.8 years (95%CI: 48.4-69.2), and 63.8 years (95%CI: 60.1-67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3-88.2%) in the microsurgery group and 54.9% (95%CI:30.7-77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7-34.5%) in the embolization group, 11.6% (95%CI:3.8-30.4%) in the microsurgery group, and 7.7% (95%CI:1.1-39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1-80.8%), embolization: 51.9% (95%CI:30.8-72.4%), and conservative: 11.6% (95%CI:4.4-27.4%)].

CONCLUSIONS

In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics.

Lower Back Pain Beyond Routine Causes: Sacral Spinal Epidural Arteriovenous Fistula (SEDAVF)

Lower back pain (LBP) is a frequent complaint, even among young people. The most common cause is attributed to slipped discs or vertebral fractures. Less common etiologies should also be considered when presenting with typical symptoms of severe backache. Here, we are presenting one such uncommon case. A 32-year-old man with a history of meningocele repair in neonates presented with severe backache, urinary retention, and constipation in an emergency. Initially, the patient was treated elsewhere, but symptoms persisted. A contrast-enhanced MRI done in the emergency revealed a rare sacral spinal epidural arteriovenous fistula (SEDAVF) with cord congestion. The patient was taken up for digital subtraction angiography, which confirmed the diagnosis, and was treated successfully with endovascular embolization. This case highlights the complex presentation of SEDAVF and the importance of prompt diagnosis and intervention.

Intramedullary feeder aneurysm of a cervical epidural arteriovenous fistula causing myelopathy: a case report and literature review

While a craniocervical junction (CCJ) epidural arteriovenous fistula (EDAVF) may present with hemorrhagic myelopathy from an associated feeder aneurysm on rare occasions, non-hemorrhagic myelopathy from such an aneurysm remains unreported. A woman in her late sixties presented with cervical myelopathy due to a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF. The intramedullary aneurysm originated from the spinal pial artery supplied by the anterior spinal artery. Direct surgical fistula coagulation and feeder obliteration resulted in the disappearance of the aneurysm and myelopathy improvement. This report illustrates the first case of a non-hemorrhagic intramedullary aneurysm associated with CCJ-EDAVF successfully treated with direct surgery.

Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: A Technical Note and Literature Review

BACKGROUND

Sacral extradural arteriovenous fistula (SEAVF) is relatively rare, and its etiology is unknown. They are mostly fed by the lateral sacral artery (LSA). For endovascular treatment, both the stability of the guiding catheter and accessibility of the microcatheter to the fistula, distal to the LSA are required for sufficient embolization of the fistulous point. Cannulation of these vessels requires either crossover at the aortic bifurcation or retrograde cannulation using the transfemoral approach. However, atherosclerotic femoral and tortuous aortoiliac vessels can make the procedure technically difficult. Although the right transradial approach (TRA) can reduce this difficulty by straightening the access route, a potential risk remains for cerebral embolism because it passes the aortic arch. Herein, we present a case of successful embolization of a SEAVF using a left distal TRA.

METHODS

We report a case of a 47-year-old man with SEAVF treated with embolization using a left distal TRA. Lumbar spinal angiography showed a SEAVF with an intradural vein through the epidural venous plexus fed by the left LSA. A 6-French guiding sheath was cannulated into the internal iliac artery via the descending aorta using the left distal TRA. A microcatheter could be advanced into the extradural venous plexus over the fistula point from the intermediate catheter placed at the LSA. Embolization with coils and n-butyl cyanoacrylate was successfully performed.

RESULTS

The SEAVF completely disappeared on neuroimaging, and the patient gradually recovered.

CONCLUSIONS

Left distal TRA could be a useful, safe, and less invasive option for the embolization of SEAVF, especially for patients with high-risk factors for aortogenic embolism or puncture site complications.

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.

Challenging Myelopathy Cases

Misdiagnosis of myelopathies is common and can lead to irreversible disability when diagnosis- and disease-specific treatments are delayed. Therefore, quickly determining the etiology of myelopathy is crucial. Clinical evaluation and MRI spine are paramount in establishing the correct diagnosis and subsequently an appropriate treatment plan. Herein, we review an approach to myelopathy diagnosis focused on the time course of neurologic symptom progression and neuroimaging pearls, and apply them to a variety of inflammatory, structural, and vascular myelopathy cases.

Recognition of the variant type of spinal dural arteriovenous fistula: a rare but important consideration

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series.

METHODS

Following institutional review board approval, the authors retrospectively analyzed their prospectively maintained database of patients with SDAVFs who presented between 2008 and 2020. For all patients, spinal digital subtraction angiograms were reviewed and variant SDAVFs were identified. Variant types of SDAVFs were defined as cases in which the fistulous point was not located underneath the pedicle. Patient demographics, angiographic features, clinical outcomes, and treatment modalities were assessed.

RESULTS

Of 59 patients with SDAVFs treated at the authors' institution, 4 patients (6.8%) were identified as having a variant location of the shunt zone, pinpointed on the dura mater at the intervertebral level, further posteriorly within the spinal canal. In 3 cases (75%), a so-called bimetameric arterial supply was demonstrated.

CONCLUSIONS

Recognition of the variant type of SDAVF is crucial for management, as correct localization of the fistulous point and bimetameric supply are critical for successful surgical disconnection, preventing delay in achieving definitive treatment.

Spinal epidural arteriovenous fistula in 3 cats

Three young adult cats with intermittent spinal hyperesthesia and paraparesis and diagnosed with spinal epidural arteriovenous fistula are described. In all 3 cases, magnetic resonance imaging (MRI) showed focal dilatation of the veins in the epidural space of the thoracic spinal cord, whereas computed tomography angiography (CTA) showed dilatation and enhancement from the intercostal vein to the azygos vein at the same site in the arterial phase. Dorsal laminectomy and occlusion of the interarcuate branches running across the dorsal aspect of the spinal cord were performed in all 3 cats to decompress the spinal cord, which resulted in a remission of clinical signs and no recurrence during 14 to 40 months of follow‐up after surgery in all cases.

Pathophysiology and classification of intracranial and spinal dural AVF

Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. DAVFs are relatively rare, however, DAVFs can lead to significant morbidity and mortality due to intracranial hemorrhage and non-hemorrhagic neurologic deterioration related to leptomeningeal venous drainage. The etiology and pathophysiology of DAVFs is not fully understood. Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. Herein, incidence, etiology, pathophysiology of development of intracranial and spinal DAVF including their classifications are briefly described with short historical review.

Treatment of Spinal Arteriovenous Malformation and Fistula

With the rapid advancements in endovascular therapy over previous decades, the treatment of spinal arteriovenous malformations (AVMs) continues to evolve. The decision to use endovascular versus surgical therapy largely depends on the type of lesion and its anatomic location. Recent studies demonstrate that endovascular treatment is effective for extradural arteriovenous fistulas (AVFs), intradural ventral (perimedullary) AVMs, and intramedullary spinal AVMs. Treatment of intradural dorsal (dural) AVFs remains largely surgical because of lower recurrence rates, although recent studies demonstrate equivocal outcomes. Extradural-intradural (juvenile) AVMs and conus AVMs remain difficult-to-treat lesions.

Endovascular Treatment of a Lumbar Spinal Epidural Arteriovenous Fistula with Radiculopathy: A Case Report

Spinal epidural arteriovenous fistulas (SEDAVFs) are rare spinal vascular malformations that are difficult to diagnose and treat. SEDAVFs can be asymptomatic; however, symptoms can arise from the compression of adjacent nerve roots by dilated vein and perimedullary venous reflux, caused by shunting into the epidural venous plexus. A 31-year-old male presented to our institution with a 2-year history of progressively worsening low-back pain, radiating thigh pain, and sensory changes in his lower extremities. MRI and CT angiography demonstrated dilated epidural vascular lesion compressing the nerve root. The SEDAVF was embolized with multiple coils, which alleviated the nerve root compression from the engorged venous varix and improved the patient's radiculopathy. Our experience from this case shows that endovascular coil embolization using the transarterial approach can be an effective treatment for SEDAVF and an alternative to surgical ligations.

Incidence and clinical characteristics of spinal arteriovenous shunts: hospital-based surveillance in Okayama, Japan

OBJECTIVE

There have been no accurate surveillance data regarding the incidence rate of spinal arteriovenous shunts (SAVSs). Here, the authors investigate the epidemiology and clinical characteristics of SAVSs.

METHODS

The authors conducted multicenter hospital-based surveillance as an inventory survey at 8 core hospitals in Okayama Prefecture between April 1, 2009, and March 31, 2019. Consecutive patients who lived in Okayama and were diagnosed with SAVSs on angiographic studies were enrolled. The clinical characteristics and the incidence rates of each form of SAVS and the differences between SAVSs at different spinal levels were analyzed.

RESULTS

The authors identified a total of 45 patients with SAVSs, including 2 cases of spinal arteriovenous malformation, 5 cases of perimedullary arteriovenous fistula (AVF), 31 cases of spinal dural AVF (SDAVF), and 7 cases of spinal epidural AVF (SEAVF). The crude incidence rate was 0.234 per 100,000 person-years for all SAVSs including those at the craniocervical junction (CCJ) level. The incidence rate of SDAVF and SEAVF combined increased with advancing age in men only. In a comparative analysis between upper and lower spinal SDAVF/SEAVF, hemorrhage occurred in 7/14 cases (50%) at the CCJ/cervical level and in 0/24 cases (0%) at the thoracolumbar level (p = 0.0003). Venous congestion appeared in 1/14 cases (7%) at the CCJ/cervical level and in 23/24 cases (96%) at the thoracolumbar level (p < 0.0001).

CONCLUSIONS

The authors reported detailed incidence rates of SAVSs in Japan. There were some differences in clinical characteristics of SAVSs in the upper spinal levels and those in the lower spinal levels.

Embolization Tactics of Spinal Epidural Arteriovenous Fistulas

Purpose

Spinal epidural arteriovenous fistulas (SEDAVFs) show an epidural venous sac often with venous congestive myelopathy (VCM) due to intradural reflux at a remote level to which a transarterial approach would be difficult. We present 12 cases of SEDAVF with VCM and describe 3 main tactics for effective transarterial embolization.

Materials and Methods

Among 152 patients with spinal vascular malformations diagnosed in our tertiary hospital between 1993 and 2019, 12 SEDAVF patients with VCM were included. Three different transarterial embolization tactics were applied according to the vascular configuration and microcatheter accessibility. We evaluated treatment results and clinical outcomes before and after treatment.

Results

Transarterial embolization with glue (20–30%) was performed in all patients. The embolization tactics applied in 12 patients were preferential flow (n=2), plug-and-push (n=6), and filling of the venous sac (n=4). Total occlusion of the SEDAVF, including intradural reflux, was achieved in 11 (91.7%) of 12 patients, and partial occlusion was achieved in 1 patient. No periprocedural complications were reported. Spinal cord edema was improved in all patients for an average of 18 months after treatment. Clinical functional outcome in terms of the pain, sensory, motor, and sphincter scale and modified Rankin scores improved during a mean 25-month follow-up (6.3 vs. 3.3, P=0.002; 3.6 vs. 2.3, P=0.002, respectively).

Conclusion

Endovascular treatment for 12 SEDAVF patients with VCM achieved a total occlusion rate of 91.7% without any periprocedural complication. The combined embolization tactics can block intradural reflux causing VCM, resulting in overall good clinical outcomes.

Natural History and Clinical Outcomes of Paravertebral Arteriovenous Shunts

BACKGROUND AND PURPOSE

Paravertebral arteriovenous shunts (PVAVSs) are rare. Whether the intradural venous system is involved in drainage may lead to differences in clinical characteristics through specific pathophysiological mechanisms. This study aims to comprehensively evaluate the natural history and clinical outcomes of PVAVSs with or without intradural drainage.

METHODS

Sixty-four consecutive patients with PVAVSs from 2 institutes were retrospectively reviewed. Lesions were classified as type A (n=28) if the intradural veins were involved in drainage; otherwise, they were classified as type B (n=36). The clinical course from initial presentation to the last follow-up was analyzed.

RESULTS

The patients with type A shunts were older at presentation (52.5 versus 35.5 years, P<0.0001) and more likely to have lower spinal segments affected than patients with type B PVAVSs (67.8% versus 13.9%, P=0.00006). After presentation, the deterioration rates related to gait and sphincter dysfunction were significantly higher in patients with type A than type B shunts (gait dysfunction: 71.8%/y versus 17.0%/y, P=0.0006; sphincter dysfunction: 63.7%/y versus 11.3%/y, P=0.0002). According to the angiogram at the end of the latest treatment, 79% of type A and 75% of type B PVAVSs were completely obliterated. If the lesions were partially obliterated, a significantly higher clinical deterioration rate was observed in patients with type A shunts than those with type B shunts (69.9%/y versus 3.2%/y, P=0.0253).

CONCLUSIONS

Type A PVAVSs feature rapid progressive neurological deficits; therefore, early clinical intervention is necessary. For complex lesions that cannot be completely obliterated, surgical disconnection of all refluxed radicular veins is suggested.

Challenges in Diagnosis and Management of Previously Embolized Spinal Dural Arteriovenous Fistulae

BACKGROUND

Given the growing prevalence of initial endovascular treatment for type 1 spinal dural arteriovenous fistulae (dAVF), there are an increasing number of patients presenting with progressive symptoms related to recurrent previously embolized spinal dAVF. This study's goal was to identify demographic, clinical, and radiographic variables among patients who have failed embolization of type I spinal dAVF.

METHODS

A retrospective review of 24 consecutive surgeries for type I spinal dAVF performed by the senior author (A.D.L.) identified 5 patients who underwent open surgery for failed embolization. These 5 cases were reviewed for location of fistula, time from embolization to recurrence, preoperative functional status, fistulous point encountered at surgery, and clinical outcome of the patient at 3-month follow-up. A representative example case is reviewed in detail.

RESULTS

The median age at time of recurrence was 63 years (range 51-73 years). The median timing of embolization to recurrence of neurologic symptoms was 5 months (range 1-54) and to surgery 7 months (range 2-60 months). The level of the spinal dAVF was most frequently at T12-L1 (n = 3). Spinal magnetic resonance arteriography led to localization of the spinal dAVF in 2 patients and spinal catheter angiogram in 3 cases. All patients had definitive radiographic cure of the dAVF at last clinical follow-up.

CONCLUSIONS

The increased use of endovascular treatment of spinal dAVF has led to the treatment of refractory cases with a greater degree of surgical complexity. Open surgical ligation continues to provide the most definitive treatment outcomes for this complex spinal vascular entity.

Spinal epidural arteriovenous fistula with intradural venous reflux: The possibility of acquired origin caused by spinal stenosis and/or disc herniation

BACKGROUND

Spinal epidural arteriovenous fistulas (SEAVFs) are relative rare lesions. The pathogenesis of these fistulas remains unclear. Our aim is to review cases of SEAVFs at our institution.

METHODS

We reviewed a consecutive series of spinal vascular disease at our institution and collected all patients harboring SEAVFs. Medical charts were retrospectively reviewed regarding patient demographic data (i.e., gender and age), presenting symptoms and signs, previous history of spinal surgery or trauma, treatment methods, and neurological outcome after treatment. All image studies, including plain radiography, spinal MRI, MRA, and angiography were analyzed.

RESULTS

We identified 9 cases of lumbosacral SEAVFs with intradural venous reflux treated at our institution from June 2010 to August 2020. Their median age was 67 years, range 52-83 years. Only one patient had a history of trauma. Interestingly, our observations found that all fistulas are associated with spinal stenosis and/or disc herniation. An additional literature search about SEAVFs coexisting with spinal stenosis and/or disc herniation was performed and found another 19 cases with median age 69 years, range 39-83 years. Only 2 patients had a history of previous spinal surgery. The level of shunted pouch in all 28 patients was correlated with the level of spinal canal stenosis and/or disc herniation.

CONCLUSIONS

Our study may provide an additional evidence supporting an acquired etiology of SEAVFs, which mainly manifest in late adulthood. It is possible that spinal stenosis and/or disc herniation may result in thrombosis or impairment of venous drainage, causing increased venous pressure, leading to fistulous formation.

Thoracolumbar intraosseous spinal epidural arteriovenous fistulas after vertebral compression fracture: A case report and literature review

BACKGROUND

The pathophysiology of spinal epidural arteriovenous fistulas (SEAVFs) with perimedullary venous drainage remains to be elucidated. This report describes a case of intraosseous SEAVF in a patient with a history of a thoracolumbar vertebral fracture at the same level 10 years before presenting with progressive myelopathy secondary to retrograde venous reflux into the perimedullary vein.

CASE DESCRIPTION

A 71-year-old man presenting with progressive paraparesis was diagnosed with a SEAVF involving a previous Th12 and L1 vertebral compression fracture on which feeders from multiple segmental arteries converged. The interesting feature of this case was that the fistula was located in the fractured vertebral body. The fistula was totally obliterated by transarterial embolization of the segmental arteries followed by symptom improvement.

CONCLUSION

We presented a rare case of an intraosseous SEAVF secondary to a thoracolumbar compression fracture with perimedullary venous reflux causing progressive myelopathy. The fistula was located in the fractured vertebral body.

Vascular Spinal Cord Disorders

Vascular disorders of the spinal cord are uncommon yet under-recognized causes of myelopathy. Etiologies can be predominantly categorized into clinical and radiographic presentations of arterial ischemia, venous congestion/ischemia, hematomyelia, and extraparenchymal hemorrhage. While vascular myelopathies often produce significant morbidity, recent advances in the understanding and recognition of these disorders should continue to expedite diagnosis and proper management, and ideally improve patient outcomes. This article comprehensively reviews relevant spinal cord vascular anatomy, clinical features, radiographic findings, treatment, and prognosis of vascular disorders of the spinal cord.

Clinical and Imaging Characteristics of Spinal Dural Arteriovenous Fistulas and Spinal Epidural Arteriovenous Fistulas

BACKGROUND

Spinal epidural arteriovenous fistulas (SEDAVFs) are an increasingly recognized form of spinal vascular malformation and are distinct from spinal dural arteriovenous fistulas (SDAVFs). Differentiating between these 2 entities is important as operative strategies often differ based on angioarchitecture.

OBJECTIVE

To compare demographic, clinical, anatomic, and imaging findings of SDAVFs and SEDAVFs.

METHODS

Consecutive patients diagnosed and/or treated for SDAVF or SEDAVF at our institution between January 2000 and November 2018 were included. Data were collected on demographics, clinical presentation, and imaging findings. All cross-sectional and angiographic imaging were reviewed. To compare continuous variables, t-test was used Chi-squared was used for categorical variables.

RESULTS

A total of 169 patients were included. In total 47 patients had SEDAVFs and 122 patients had SDVAFs. Clinical presentation and magnetic resonance imaging (MRI) imaging findings were similar between the 2 groups. SEDAVF patients were significantly more likely to have an epidural venous pouch on gadolinium bolus MR angiography (MRA) (0.0% vs 92.1%, P < .0001). SEDAVFs were more commonly located in the lumbar and sacral spine than SDAVFs (85.1% vs 34.4%, P < .0001). When in the lumbar spine, SEDAVFs unlike SDAVFs were more likely to involve the most caudal segments (L4 and L5, P = .02).

CONCLUSION

SEDAVF share clinical and radiological findings similar to SDAVFS, including high T2 cord signal, cord enhancement, and perimedullary flow voids on conventional MRI. However, they have a characteristic appearance on spinal MRA and DSA with a pouch of epidural contrast. SEDAVFs are more commonly located in the lumbosacral spine.

Spinal Epidural Fistulas-A Separate Entity to Dural Fistulas with Different Angioarchitecture and Treatment Approach

OBJECTIVE

Spinal epidural arteriovenous fistulas (SEAVFs) are the rarest variety of spinal vascular malformation and are often misdiagnosed as type 1 spinal dural fistula. This retrospective study highlights the salient anatomic differentiating points of these entities and also highlights the importance of a planned endovascular treatment approach using different routes of access. Efficacy of the endovascular treatment at 3 months follow-up was also studied.

METHODS

We retrospectively reviewed 11 treated patients with SEAVF. Existence of epidural arteriovenous fistula in all these patients was confirmed by spinal angiography. The Aminoff-Logue Scale score was assigned both before and after the procedure. The statistical results were expressed as percentages, and the preprocedure scale was compared with the postprocedure scale at 3 months by using a nonparametric Wilcoxon signed-rank test.

RESULTS

The patients ranged in age from 7 to 53 years, with male predominance. Paraparesis was the commonest symptom, and 1 patient had congestive cardiac failure caused by a large fistula. Location was mostly dorsolumbar with intradural venous reflux into the perimedullary venous system (Castilla type A) noted in 3/11(27%) patients, and the remaining 73% patients had Castilla type B1 with an enlarged epidural venous sac. Therapeutic embolization was performed from arterial, venous, or combined routes. The 3-month postprocedure clinical assessment showed statistically significant (P < 0.004) improvement in the Aminoff-Logue Scale score.

CONCLUSIONS

The differentiating points between SEAVF compared with type 1 spinal dural fistula are emphasized. The study also highlights the importance of a good angiographic assessment to best access the fistula by arterial, venous, percutaneous, or combined routes. Endovascular treatment resulted in statistically significant clinical improvement at 3 months follow-up.

Microsurgical versus endovascular treatment of spinal epidural arteriovenous fistulas with intradural venous drainage: a multicenter study of 81 patients

OBJECTIVE

Spinal arteriovenous shunts are rare vascular lesions and are classified into 4 types (types I-IV). Due to rapid advances in neuroimaging, spinal epidural AVFs (edAVFs), which are similar to type I spinal dural AVFs (dAVFs), have recently been increasingly reported. These 2 entities have several important differences that influence the treatment strategy selected. The purposes of the present study were to compare angiographic and clinical differences between edAVFs and dAVFs and to provide treatment strategies for edAVFs based on a multicenter cohort.

METHODS

A total of 280 consecutive patients with thoracic and lumbosacral spinal dural arteriovenous fistulas (dAVFs) and edAVFs with intradural venous drainage were collected from 19 centers. After angiographic and clinical comparisons, the treatment failure rate by procedure, risk factors for treatment failure, and neurological outcomes were statistically analyzed in edAVF cases.

RESULTS

Final diagnoses after an angiographic review included 199 dAVFs and 81 edAVFs. At individual centers, 29 patients (36%) with edAVFs were misdiagnosed with dAVFs. Spinal edAVFs were commonly fed by multiple feeding arteries (54%) shunted into a single or multiple intradural vein(s) (91% and 9%) through a dilated epidural venous plexus. Preoperative modified Rankin Scale (mRS) and Aminoff-Logue gait and micturition grades were worse in patients with edAVFs than in those with dAVFs. Among the microsurgical (n = 42), endovascular (n = 36), and combined (n = 3) treatment groups of edAVFs, the treatment failure rate was significantly higher in the index endovascular treatment group (7.5%, 31%, and 0%, respectively). Endovascular treatment was found to be associated with significantly higher odds of initial treatment failure (OR 5.72, 95% CI 1.45-22.6). In edAVFs, the independent risk factor for treatment failure after microsurgery was the number of intradural draining veins (OR 17.9, 95% CI 1.56-207), while that for treatment failure after the endovascular treatment was the number of feeders (OR 4.11, 95% CI 1.23-13.8). Postoperatively, mRS score and Aminoff-Logue gait and micturition grades significantly improved in edAVFs with a median follow-up of 31 months.

CONCLUSIONS

Spinal epidural AVFs with intradural venous drainage are a distinct entity and may be classified as type V spinal vascular malformations. Based on the largest multicenter cohort, this study showed that primary microsurgery was superior to endovascular treatment for initial treatment success in patients with spinal edAVFs.

Posttraumatic Vertebral Arteriovenous Fistula: A Lifeline from Tetraplegia?

BACKGROUND

Vertebral artery (VA) rupture is a rare condition that occurs about in 0.5% of cervical trauma. The management of our case was complicated by a spinal epidural hematoma (SEH) leading to worsening neurologic deficits. Only 1 similar case has been reported before in the literature.

CASE DESCRIPTION

We report the case of a 37-year-old victim of a serious car accident. Shortly after admission to the emergency department, she developed weakness in all 4 limbs and sensory deficit below T6 level. Cervical spine computed tomography scan revealed an SEH from C1 to T3. Computed tomography angiography scan showed rupture of the left VA at C3 level, with a posttraumatic vertebral arteriovenous fistula at the same level, draining in the epidural venous plexus and to the right jugular internal vein. Immediately after embolization of the left VA, we performed a cervical decompression from C2 to C7. Three months after surgery the patient had a full recovery.

CONCLUSIONS

No guidelines exist to treat this situation. We propose consequential steps to treat a posttraumatic cervical SEH with evidence of VA rupture.

Transvenous embolization for craniocervical junction epidural arteriovenous fistula with a pial feeder aneurysm

Arteriovenous fistulas at the craniocervical junction are rare vascular malformations with frequent hemorrhagic presentations, which may have a concurrent pial feeder aneurysm. A 65-year-old man presented with subarachnoid hemorrhage and angiography showed an epidural arteriovenous fistula at the C-2 level with an anterior spinal feeder aneurysm without perimedullary venous drainage. Transarterial coil embolization of the ruptured aneurysm and partial Onyx embolization of the shunt led to thrombosis of the aneurysm. However, three years later angiography showed an increased shunt flow and recurrence of the aneurysm. Transvenous embolization of the shunt using coils and Onyx yielded complete obliteration of the shunt, thus leading to occlusion of the aneurysm. This case demonstrates that partial transarterial embolization of arteriovenous fistula leaves a risk of rebleeding, whereas complete obliteration of the shunt with a transvenous approach can lead to disappearance of the flow-related aneurysm without embolization of the aneurysm itself.

Challenging dogma: report of a spinal cord arteriovenous malformation as an acquired lesion in a pediatric patient

Spinal cord intramedullary arteriovenous malformations (AVMs) have classically been considered congenital lesions that are present from birth. The reason for this dogmatic principal is the fact that a vast majority of these lesions present in pediatric and young adult patients. Interestingly, while many authors have demonstrated the development of de novo nidus-type brain AVMs, there have been no reported cases of a de novo intramedullary or perimedullary AVM of the spine. In this paper the authors describe what they believe to be the first reported case of a de novo AVM of the spinal cord in a young patient who underwent serial imaging from birth for evaluation of a syrinx. Potential pathophysiological mechanisms for the development of de novo vascular malformations of the spinal cord are discussed.

Osseous versus Nonosseous Spinal Epidural Arteriovenous Fistulas: Experiences of 13 Patients

BACKGROUND AND PURPOSE

Spinal epidural arteriovenous fistulas are rare vascular malformations. We present 13 patients with spinal epidural arteriovenous fistulas, noting the various presenting symptom patterns, imaging findings related to bone involvement, and outcomes.

MATERIALS AND METHODS

Among 111 patients with spinal vascular malformations in the institutional data base from 1993 to 2017, thirteen patients (11.7%) had spinal epidural arteriovenous fistulas. We evaluated presenting symptoms and imaging findings, including bone involvement and mode of treatment. To assess the treatment outcome, we compared initial and follow-up clinical status using the modified Aminoff and Logue Scale of Disability and the modified Rankin Scale.

RESULTS

The presenting symptoms were lower back pain (n = 2), radiculopathy (n = 5), and myelopathy (n = 7). There is overlap of symptoms in 1 patient (No. 11). Distribution of spinal epidural arteriovenous fistulas was cervical (n = 3), thoracic (n = 2), lumbar (n = 6), and sacral (n = 2). Intradural venous reflux was identified in 7 patients with congestive venous myelopathy. The fistulas were successfully treated in all patients who underwent treatment (endovascular embolization, n = 10; operation, n = 1) except 2 patients who refused treatment due to tolerable symptoms. Transarterial glue (n = 7) was used in nonosseous types; and transvenous coils (n = 3), in osseous type. After 19 months of median follow-up, the patients showed symptom improvement after treatment.

CONCLUSIONS

Although presenting symptoms were diverse, myelopathy caused by intradural venous reflux was the main target of treatment. Endovascular treatment was considered via an arterial approach in nonosseous types and via a venous approach in osseous types.

Lumbar tap-induced subarachnoid hemorrhage in a case of spinal epidural arteriovenous fistula

The authors report the case of a 70-year-old woman with lumbar spinal epidural arteriovenous fistula (SEDAVF) who experienced subarachnoid hemorrhage (SAH) after a diagnostic lumbar puncture. According to the literature, perimedullary spinal vein enlargement is a hallmark of spinal vascular diseases; however, there are certain cases in which routine sagittal MRI fails to disclose signal flow voids. In such cases, patients may undergo a lumbar tap to investigate the possible causes of spinal inflammatory or demyelinating disease. Recognizing this phenomenon is essential because lumbar puncture of the epidural venous pouch or an enlarged intradural vein in SEDAVF may induce severe SAH. A high clinical index of suspicion can prevent similar cases in lumbar SEDAVF.

Spinal Epidural Arteriovenous Fistula with Perimedullary Venous Reflux: Clinical and Neuroradiologic Features of an Underestimated Vascular Disorder

BACKGROUND AND PURPOSE

The purpose of this study was to discuss the clinical and radiologic characteristics of spinal epidural arteriovenous fistulas (SEAVF) and demonstrate their specific angiomorphology in a single-center series.

MATERIALS AND METHODS

Thirteen consecutive patients were diagnosed with SEAVF at RWTH Aachen University Hospital between 2006 and 2018 and were included in this study. All patients had MR imaging and DSA before treatment; 10 of these 13 patients received contrast-enhanced MRA (CE-MRA).

RESULTS

The mean patient age was 72 ± 8 years. Paraparesis was present in 12 (92%) patients. Sphincter dysfunction and sensory symptoms were observed in 7 (54%) and 6 (46%) patients, respectively. The mean duration of symptoms was 6 ± 8 months. Congestive myelopathy on MR imaging was present in all patients. Prominent arterialized perimedullary veins were demonstrated in only 3 cases. CE-MRA revealed arterialized perimedullary veins and an arterialized epidural pouch in 9/10 (90%) patients, mostly located ventrolaterally. DSA demonstrated a multisegmental extension of the arterialized ventrolateral epidural pouch in 6 (46%) cases. An intradural radicular drainage vein was localized distant from the original fistula point in 3 (23%) patients.

CONCLUSIONS

Congestive myelopathy with an acute/subacute clinical course was the dominant finding in spinal epidural arteriovenous fistulas. CE-MRA is a powerful diagnostic tool for identifying arterialized perimedullary veins as well as an arterialized epidural pouch. While arterialized perimedullary veins frequently present with only mild enlargement and elongation in spinal epidural arteriovenous fistulas, the arterialized epidural pouch is frequently located ventrolaterally and may extend over several vertebral levels. DSA remains the criterion standard to precisely visualize a spinal epidural arteriovenous fistula and its intradural radicular drainage vein, which may be located distant from the fistulous point.

Dilated Vein of the Filum Terminale on MRI: A Marker for Deep Lumbar and Sacral Dural and Epidural Arteriovenous Fistulas

BACKGROUND AND PURPOSE

Conventional MR imaging can provide important clues regarding the location of a spinal vascular malformation. We hypothesized that a dilated vein of the filum terminale, identified as a curvilinear flow void on T2WI, could be an imaging marker for a lower lumbar (L3-L5) or sacral fistula.

MATERIALS AND METHODS

We retrospectively identified all spinal dural and spinal epidural arteriovenous fistulas from 2 large tertiary referral centers from 2005 to 2018. All patients had a lumbar spinal MR imaging and a conventional spinal angiography. Images were reviewed by 2 neuroradiologists who categorized the level of the arterial feeder to the fistula and the presence or absence of a dilated vein of the filum terminale on T2WI and T1 postcontrast images. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula.

RESULTS

One hundred sixty-two patients were included. An enlarged filum terminale vein was identified in 39 patients. Sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula were 86%, 98.3%, 94.9%, and 95.1%, respectively.

CONCLUSIONS

The presence of a dilated vein of the filum terminale can accurately localize a spinal dural arteriovenous fistula/spinal epidural arteriovenous fistula to the lower lumbar or sacral spine in patients being evaluated for such lesions. This finding can be used to facilitate both noninvasive and conventional spinal angiography.

Presentation and outcomes of patients with thoracic and lumbosacral spinal epidural arteriovenous fistulas: a systematic review and meta-analysis

Background and purpose

Thoracolumbar and sacral spinal epidural arteriovenous fistulas (SEDAVFs) are an increasingly recognized form of spinal vascular malformation. The purpose of this study was to perform a systematic review of the demographics, clinical presentation and treatment results of thoracolumbar SEDAVFs.

Materials and methods

Pubmed, Scopus and Web of Science databases were searched from January 2000 to January 2018 for articles on treatment of SEDAVFs. Pooled data of individual patients were analyzed for demographic and clinical features of SEDAVFs as well as treatment outcomes.

Results

There were 125 patients from 11 studies included. Mean age was 63.5 years. There was a male sex predilection (69.6%). Sensory symptoms including pain or numbness were the most frequently presenting symptoms. Fistula location was the lumbosacral spine in 79.2% and the thoracic spine in 20.8%. Involvement of intradural venous drainage was more common than extradural venous drainage only (89.6% vs 10.4%). Of the 123 treated patients, endovascular therapy was performed in 67.5% of patients, microsurgery in 23.6%, and combined treatment in 8.9%. The overall complete obliteration rate was 83.5% and did not differ between groups. Clinical symptoms improved in 70.7% of patients, were stable in 25%, and worsened in 1.7% with no difference between treatment modalities.

Conclusions

Thoracic and lumbosacral SEDAVFs often present with symptoms secondary to congestive myelopathy or compressive symptoms. Both endovascular and microsurgical treatments were associated with high obliteration rates and good clinical outcomes.

Spinal Arteriovenous Vascular Malformations in Patients with Neural Tube Defects

BACKGROUND AND PURPOSE

Neural tube defects, such as tethered cord, intradural lipoma, or myelomeningocele may coexist with spinal vascular malformations. The coexistence of these 2 rare entities is suggestive of a causal relationship between them, which may lead to further understanding of their pathogenesis. We present a series of 6 patients with epidural spinal arteriovenous fistulas associated with neural tube defects.

MATERIALS AND METHODS

We retrieved cases of spinal vascular malformations associated with neural tube defects seen at our institution. The clinical presentation, MR imaging/MRA and angiographic imaging, treatment outcomes, and long-term neurologic outcomes were analyzed. Descriptive statistical analyses are reported.

RESULTS

Six patients with epidural arteriovenous fistulas and neural tube defects were included in this study. The mean age at presentation was 42 years, and the most common presenting symptoms were lower extremity weakness followed by sensory disturbances and bladder/bowel dysfunction. In most cases (5/6), the fistulas were located at the sacral level. All cases were fed by the lateral sacral artery (6/6). Four patients had prior spine surgery, but the fistula was in the operative bed in 2 cases. All fistulas were extradural with secondary intradural venous drainage. Five patients underwent transarterial embolization with Onyx, and 1 patient had a treatment-related complication.

CONCLUSIONS

It is conceivable that there is a pathophysiologic link between neural tube defects and development of spinal vascular malformations. Delayed neurologic deterioration or high conus signal in a patient with a neural tube defect should suggest the possibility of such an association.

Angiographic and Clinical Characteristics of Thoracolumbar Spinal Epidural and Dural Arteriovenous Fistulas

BACKGROUND AND PURPOSE

The purpose of this study is to compare the angiographic and clinical characteristics of spinal epidural arteriovenous fistulas (SEAVFs) and spinal dural arteriovenous fistulas (SDAVFs) of the thoracolumbar spine.

METHODS

A total of 168 cases diagnosed as spinal dural or extradural arteriovenous fistulas of the thoracolumbar spine were collected from 31 centers. Angiography and clinical findings, including symptoms, sex, and history of spinal surgery/trauma, were retrospectively reviewed. Angiographic images were evaluated, with a special interest in spinal levels, feeders, shunt points, a shunted epidural pouch and its location, and drainage pattern, by 6 readers to reach a consensus.

RESULTS

The consensus diagnoses by the 6 readers were SDAVFs in 108 cases, SEAVFs in 59 cases, and paravertebral arteriovenous fistulas in 1 case. Twenty-nine of 59 cases (49%) of SEAVFs were incorrectly diagnosed as SDAVFs at the individual centers. The thoracic spine was involved in SDAVFs (87%) more often than SEAVFs (17%). Both types of arteriovenous fistulas were predominant in men (82% and 73%) and frequently showed progressive myelopathy (97% and 92%). A history of spinal injury/surgery was more frequently found in SEAVFs (36%) than in SDAVFs (12%; P=0.001). The shunt points of SDAVFs were medial to the medial interpedicle line in 77%, suggesting that SDAVFs commonly shunt to the bridging vein. All SEAVFs formed an epidural shunted pouch, which was frequently located in the ventral epidural space (88%) and drained into the perimedullary vein (75%), the paravertebral veins (10%), or both (15%).

CONCLUSIONS

SDAVFs and SEAVFs showed similar symptoms and male predominance. SDAVFs frequently involve the thoracic spine and shunt into the bridging vein. SEAVFs frequently involve the lumbar spine and form a shunted pouch in the ventral epidural space draining into the perimedullary vein.