Endovascular treatment of spinal arteriovenous lesions: beyond the dural fistula

Perioperative Management of Spinal Arteriovenous Malformation Embolization: Delayed Venous Thrombosis and Implications for Severe Back Pain

BACKGROUND AND PURPOSE

The prognosis of untreated spinal arteriovenous malformations (SAVMs) is poor. Embolization plays an important role in the management of intramedullary SAVMs. Delayed aggravation due to spinal venous thrombosis following successful embolization has been reported; however, perioperative management strategies to prevent thrombosis have not been explored. We present our single-center experience of SAVM embolization and perioperative management, including anticoagulation.

MATERIAL AND METHODS

We retrospectively evaluated 18 patients with SAVMs who underwent transarterial embolization. Perioperative anticoagulation therapy was administered to selected patients. We compared the characteristics of the patients, including perioperative management procedures, between those with and without postoperative worsening following embolization.

RESULTS

Acute postoperative worsening within 1 week occurred in 4 (22.2%) patients. Of these, immediate worsening was observed in one patient as a procedure-related complication. Delayed worsening after 24 h was observed in 3 patients, caused by delayed venous thrombosis with severe back pain. Rescue anticoagulation for delayed worsening improved symptoms in two patients. A comparison between patients with and without acute postoperative worsening revealed significant differences in age (median 46.5 vs. 26.5 years, p = 0.009) and the presence of postoperative back pain (75.0% vs. 0%, p = 0.005); however, there was no significant difference in use of selective anticoagulation (p = 0.274).

CONCLUSION

The results of this study suggest that SAVM embolization can cause acute worsening due to postoperative venous thrombosis with severe back pain, which may be reversed by anticoagulation therapy. Back pain is an important finding that suggests venous thrombosis, and anticoagulation should be urgently administered.

Diagnostic, clinical management, and outcomes in patients with spinal dural arteriovenous fistula

Background

Spinal dural arteriovenous fistulas (SDAVFs) are rare spinal vascular malformations, but account for 70 to 80% of all spinal arteriovenous malformations. SDAVFs can be treated either surgically or endovascularly, with surgical treatment appearing to lead to higher closure rates. Our aim was to analyze the demographic data, diagnostic history, treatment characteristics and clinical short- and long-term outcomes.

Methods

The medical records of 81 patients who underwent surgical (n = 70, 86.4%) and endovascular (n = 11, 13.6%) treatment for SDAVF at a university hospital between 2002 and 2023 were retrospectively analyzed.

Results

SDAVF was observed more frequently in men than women (61, 75.3% vs. 20, 24.7%) with a mean age of 63.5 ± 12.7 years and a mean duration of symptoms to diagnosis of 12.0 ± 12.8 months. The most common first symptom was gait disturbance (36, 44.4%), followed by sensory disturbance (24, 29.6%). The location of the fistula point was most common in the lower thoracic region (36, 44.5%), followed by the lumbar region (23, 28.4%). Incomplete or failed occlusion of the fistula occurred in 8 patients (9.9%), with 6 patients (7.4%) undergoing further treatment either surgically or endovascularly. Treatment- or hospital-related complications were observed in 16 patients (19.8%). A single-level laminectomy was the most common approach (31, 44.3%), followed by single-level hemilaminectomy (28, 40.0%), and unilateral interlaminar fenestration (11, 15.7%). Back pain or radiculopathy was observed in 58% of patients (47/81) pre-treatment and had already decreased to 24.7% at hospital discharge (p < 0.001). No significant differences were observed in sensory disturbances (p = 0.681). The median of American Spinal Injury Association motor score (ASIA-MS) was 94 [82.5-100] at admission, 98 [86.5-100] at hospital discharge, 100 [90-100] at the first, second, and third follow-up (p = 0.019). The median modified Aminoff-Logue scale (mALS) was 5 [2-7] at admission, 3 [1-6] at hospital discharge, 2 [1-5] at the first follow-up, 2 [0.5-5] at the second follow-up and 2 [1-7] at the third follow-up (p = 0.006).

Conclusions

SDAVF occurs predominantly in men in the 6th decade of life and can be safely and effectively treated surgically and endovascularly, improving symptoms such as pain and motor deficits, gait disturbances as well as bowel and bladder dysfunction, but not sensory disturbances.

Endovascular treatment of epidural arteriovenous fistula associated with sacral arteriovenous malformation: case report

Spinal epidural arteriovenous fistulas with sacral arteriovenous malformation (AVM) are a rare type of spinal arteriovenous fistulas. There are two varieties of spinal epidural arteriovenous fistulas (SEDAVFs), with type 1 involving intradural venous drainage and type 2 not involving intradural venous drainage. We present a case of transarterial embolization for type 1 SEDAVFs with sacral AVM. Within 8 months, a 14-year-old boy presented with progressively weaker lower extremities and bladder-bowel dysfunction. Magnetic resonance imaging (MRI) of the whole spine revealed thoracic spinal cord congestion, a single dilated flow void running from the lumbosacral area to the conus medullaris, and continuing cranial draining up to the C5 level via the perimedullary vein. Filling of the venous sac through a preferential feeder after embolizing the AVM nidus was performed. After 3 months, the clinical follow-up showed improvement of motoric function, although mild. Endovascular treatment for SEDAVF type 1 might have achieved total obliteration without any procedural complications. Nevertheless, it can be very challenging due to multiple feeders and the presence of an AVM nidus like in this case. However, the most difficult thing in fistula cases is establishing the diagnosis and finding the fistula point. Early treatment is required, due to the fact that longstanding lesions could cause irreversible damage.

A rare case of sacral epidural arteriovenous fistula with concomitant occult multiple lumbar epidural arteriovenous fistulas

We describe a rare case of sacral epidural arteriovenous fistulas (edAVFs) with atypical clinical course of treatment. A 78-year-old man with a history of spinal surgery presented progressive gait disturbance and urinary incontinence. Spinal angiography demonstrated a sacral spinal AVF fed by bilateral lateral sacral arteries, draining to the venous pouch with subdural drainage. The first treatment by direct interruption of a subdural drainer was incompletely finished. Postoperative reassessment by 3D imaging analysis led to the diagnosis of sacral edAVF and 3D understanding of its angioarchitecture. The second treatment by transarterial embolization (TAE) resulted in complete occlusion of a sacral edAVF. However, spinal venous congestion didn't improve, because the recruitment of occult edAVFs at the multiple lumbar levels and complex-shaped sacral ventral epidural venous plexus (VEP) were involved in the remnant of prior subdural drainage. The third treatment was performed by TAE for three occult edAVFs and the VEP compartment connecting between a patent edAVF and subdural drainage, which resulted in complete disappearance of spinal cord edema. Endovascular embolization of VEP compartment connecting to subdural drainage in addition to fistulous occlusion may be one of the treatment options for several edAVFs at the multiple spinal levels.

Anatomical considerations regarding a high-flow arteriovenous fistula below the conus medullaris in a patient with hereditary hemorrhagic telangiectasia: Case report

BACKGROUND AND IMPORTANCE

Cauda equina radicular arteriovenous fistulas are rare "low flow" shunting lesions characterized by direct communication between the radicular artery and vein of a cauda equina nerve root. None have been associated with hereditary hemorrhagic telangiectasia and a high-flow cauda equina radicular arteriovenous fistula has never been reported. We present a unique case of a high-flow cauda equina radicular arteriovenous fistula in a patient with hereditary hemorrhagic telangiectasia. Marked flow-induced vascular remodeling posed significant diagnostic and therapeutic challenges which will be highlighted in this report.

CLINICAL PRESENTATION

A 39-year-old female with genetically confirmed hereditary hemorrhagic telangiectasia presented with progressive thoracic myelopathy secondary to a high-flow single-hole arteriovenous fistula below the conus. The feeding artery, arising from the anterior spinal artery, and draining vein had a paramedian course, favoring the diagnosis of a cauda equina radicular arteriovenous fistula (supplied by a proximal radicular artery) over a filum terminale arteriovenous fistula. Transarterial embolization was attempted but significant elongation and tortuosity of the anterior spinal artery precluded microcatheter access to the fistulous point. Surgical disconnection was successfully performed. The intraoperative findings supported the diagnosis of cauda equina radicular arteriovenous fistula. Delayed neurologic deterioration secondary to overshooting venous thrombosis was observed. She recovered after the initiation of therapeutic anticoagulation.

CONCLUSION

To the best of our knowledge, we hereby report the first high-flow cauda equina radicular arteriovenous fistula. The accurate differentiation of cauda equina radicular arteriovenous fistula from filum terminale arteriovenous fistulas, while challenging, is important to avoid treatment-related complications. Careful preoperative planning, the use of specialized endovascular and surgical techniques, and meticulous postoperative care can ensure the safe and complete disconnection of high-flow cauda equina radicular arteriovenous fistulas.

Troublemaking Lesions: Spinal Tumor Mimics

There are various mass-like lesions that can mimic true neoplasms in the spine, including inflammatory, infectious, vascular, congenital, and degenerative etiologies. While some lesions have distinctive imaging features that suggest a correct diagnosis, others have overlapping characteristics that do not allow their differentiation based solely on their imaging findings. For entities with nonspecific imaging features, knowledge of the clinical and laboratory information is critical to provide an accurate diagnosis.

Spinal Extramedullary Arteriovenous Fistulas: A 15-Year Endovascular Treatment Experience in a Tertiary Care Hospital in Thailand

BACKGROUND

Spinal arteriovenous shunts are rare diseases. Different classifications have been proposed, but the most widely used are those classified by locations. Different locations (i.e., intramedullary and extramedullary) have different treatment outcomes and different posttreatment angiographical results. Our study presents the 15-year endovascular treatment outcomes of patients who had spinal extramedullary arteriovenous fistulas (AVFs) at Ramathibodi Hospital, which is a tertiary care hospital in Thailand.

METHODS

A retrospective medical record and imaging review of all patients with spinal extramedullary AVFs, which were confirmed by a diagnostic spinal angiogram in our institute from January 2006 to December 2020, were performed. The angiographic complete obliteration rate in the first session of endovascular treatment, clinical outcomes of the patients, and complications of the procedures for all eligible patients were analyzed.

RESULTS

Sixty-eight eligible patients were included in the study. The most common diagnosis was spinal dural AVF (45.6%). The most common presenting symptoms were weakness, numbness, and bowel-bladder involvement (70.6%, 67.6%, and 57.4%, respectively). Ninety-four percent had spinal cord edema in preoperative magnetic resonance imaging. All patients had pial venous reflux. Sixty-four patients (94.1%) received endovascular treatment as the first option. The complete obliteration rate in the first session of endovascular treatment was 75% and was high in all subgroups except for the perimedullary AVF group. The overall intraoperative complication of endovascular treatment was 9.4%. Follow-up imaging showed no residual AVF in 50 patients (87.7%). Most of the patients (57.4%) had improvement of neurological functions at 3- to 6-month follow-up.

CONCLUSION

Treatment results of spinal extramedullary AVFs were good in terms of angiographic aspects and clinical outcomes. This may have resulted from the locations of the AVFs, which mostly did not involve the spinal cord arterial supply, with the exception of perimedullary AVFs. Although perimedullary AVF is difficult to treat, it can be cured by careful catherization and embolization.

Material-Specific Roadmap Modes Can Improve the Visibility of Liquid Embolic Agents for Endovascular Embolization: A Systematic In Vitro Study

BACKGROUND AND PURPOSE

Endovascular embolization using liquid embolic agents is a safe and effective treatment option for AVMs and fistulas. Because reliable visibility of these liquid embolic agents is essential for intraprocedural visual control to prevent complications, novel angiographic systems are equipped with material-specific roadmap modes. The aim of this study was the systematic in vitro comparison of conventional and material-specific roadmap modes regarding the visibility of the most used liquid embolic agents.

MATERIALS AND METHODS

A recently introduced in vitro model, resembling cerebral vessels, was embolized with Onyx 18, Squid 18, PHIL 25%, and n-BCA mixed with iodized oil (n = 4 for each liquid embolic agent), as well as with contrast medium and saline, both serving as a reference. Imaging was performed in conventional and material-specific roadmap modes. The visibility of the liquid embolic agents in both modes was compared quantitatively and qualitatively.

RESULTS

Significant differences between conventional and material-specific roadmap modes regarding the visibility of the liquid embolic agents were observed for all study groups. All liquid embolic agents were better visible in the material-specific roadmap modes compared with the conventional mode in qualitative and quantitative analyses (eg, Onyx in conventional-versus-material-specific modes along the 1.0-mm sector: mean contrast-to-noise ratio, 5.69 [SD, 0.85] versus 47.18 [SD, 5.72]; P < .001, respectively).

CONCLUSIONS

In this in vitro study, we demonstrated a better visibility of all investigated liquid embolic agents by using material-specific roadmap modes compared with the conventional roadmap technique. Especially in complex anatomic situations, these novel roadmap modes could improve the visual control and thus the safety and efficacy of embolization procedures in clinical practice.

[Spinal arteriovenous malformations]

Spinal vascular malformations include various entities such as spinal arteriovenous malformations (AVM) and represent a rare disease. Patients may present with acute or progressive sensorimotor deficits and/or nonspecific symptoms such as hypoesthesia or paresthesia, diffuse back and muscle pain, or feelings of weakness. When spinal arteriovenous malformation is suspected, magnetic resonance imaging (MRI) is the first diagnostic step to rule out other differential diagnoses, followed by a selective spinal angiography. Therapeutic options include endovascular therapy by embolization and/or surgical resection. If spinal AVM is treated properly, a significant reduction in symptoms can be achieved.

Thoracic spinal arteriovenous malformation in a 16-year-old presenting with headache

Spinal arteriovenous malformations (sAVM) are abnormally developed spinal blood vessels with an increased risk of hemorrhage. Current literature regarding sAVMs is sparse and describes classic presentations in very young children or adults. We report a unique case of a sAVM in an adolescent patient. A 16-year-old female patient presented to the emergency department with a 3-day history of headaches. Initial CT showed no abnormalities. Worsening headaches led the patient to a neurology clinic and a fundoscopy revealed papilledema. The patient was transferred to a pediatric emergency department where repeat head CT showed a possible subarachnoid hemorrhage, and a cranial MRI/MRV showed what appeared to be a non-occlusive sinus venous thrombosis. CT angiography of the head and neck showed no evidence of thrombosis, but it did reveal possible upper thoracic vascular abnormalities. Thoracic MRI revealed an intradural sAVM at T3-T5. The sAVM was successfully resected with thoracic laminectomy with reconstructive laminoplasty. The patient experienced complications with development of right lower extremity motor and sensory deficits intra-op, but is showing continued improvement. This unique case encourages emergency medicine clinicians to expand the differential diagnoses for pediatric patients presenting with a headache and intracranial hypertension without a clear intracranial cause.

Spinal arteriovenous malformation: A case report and review of literature

Spinal arteriovenous malformations are rare vascular anomalies within the paediatric age group. These anomalies are associated with devastating consequences and require prompt management to prevent the long-term neurological sequelae.

We report a case of a 10-year-old boy with tetraparesis secondary to spinal arterio- venous malformation type III (Juvenile AVM) with rapidly deteriorating neurological signs who had to be managed conservatively due to lack of advanced neurosurgical facilities and interventional radiological services in our facility and sub region.

Spinal Vascular Shunts: A Patterned Approach

Spinal vascular shunts, including fistulas and malformations, are rare and complex vascular lesions for which multiple classification schemes have been proposed. The most widely adopted scheme consists of 4 types: type I, dural AVFs; type II, intramedullary glomus AVMs; type III, juvenile/metameric AVMs; and type IV, intradural perimedullary AVFs. MR imaging and angiography techniques permit detailed assessment of spinal arteriovenous shunts, though DSA is the criterion standard for delineating vascular anatomy and treatment planning. Diagnosis is almost exclusively based on imaging, and features often mimic more common pathologies. The radiologist's recognition of spinal vascular shunts may improve outcomes because patients may benefit from early intervention.

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.

Enhanced recovery after surgery in intramedullary and extramedullary spinal cord lesions: perioperative considerations and recommendations

Enhanced recovery after surgery (ERAS) is an evidence-based approach developed to ameliorate the patient recovery process following surgical procedures. Employing a multimodal, multidisciplinary approach, ERAS implements strategies and treatment paradigms that have been shown to improve patient outcomes, reduce hospital length of stay, and ultimately reduce healthcare costs. With a substantial body of the literature supporting the implementation of ERAS in other surgical specialties, ERAS has only recently made its foray into spine surgery. Despite this, current studies are limited to spinal deformity and degenerative disease, with limited data regarding spinal cord surgery. This is due in part to the complex nature and rarity of spinal cord lesions, making the establishment of a formal ERAS protocol difficult. In developing an ERAS protocol, there must be a consensus on what factors are important to consider and implement. To address this, we reviewed the most recent advances in intramedullary and extramedullary spinal cord surgery in order to identify elements that influence patient outcomes. Using this information, the authors provide evidence-based recommendations with the intent of introducing a framework for future ERAS protocols with respect to treating spinal cord lesions.

Primary conus medullaris arteriovenous shunt and secondary lumbo-sacral epidural arteriovenous fistula: One malformation can hide another

We report an anatomical-based association between conus medullaris pial arteriovenous shunt that drain caudally towards the lumbosacral area with very delayed onset of an acquired lumbar epidural shunt, draining secondarily towards intradural veins and responsible for a venous congestive myelopathy with identical clinical symptoms. These patients require close clinical and imaging follow-ups in order to propose adequate treatments before onset of irreversible neurological deficits. MRA should include the lumbo-sacral area in its field of view.

Pediatric perimedullary arteriovenous fistula: clinical features and endovascular treatments

Objective

Pediatric spinal perimedullary arteriovenous fistula (PMAVF) is rare but may cause permanent disability. We aim to summarize the clinical features of pediatric PMAVFs and our clinical experience in their treatment and to evaluate the effect of endovascular treatment in a large cohort.

Methods

From 2008 to 2017, 51 PMAVFs in pediatric patients (<14 years' old) treated with endovascular techniques were retrospectively reviewed, including 24 type IVb (47.1%) and 27 type IVc (52.9%) lesions. Clinical features, radiological findings, treatment, and outcomes were evaluated.

Results

Thirty-eight boys and thirteen girls were included, and the mean age at presentation was 5.6±4.1 years. Acute neurological deterioration was identified in 33 patients, and 21 of those patients (63.6%) suffered from bleeding. The annual bleeding rate before treatment was 2.55%. After transarterial embolization with coils and glue, 46 PMAVFs (90.2%) were completely occluded, and five (9.8%) were obliterated by supplementary microsurgery. During a follow-up period of 6 to 119 months (mean 58.4±16.7 months), the patients’ clinical states were improved in 42 cases (82.4%), stationary in nine cases (17.6%), and aggravated in none. Type IVc patients had a longer preoperative period, more chronic symptoms, a lower cure rate by embolization, and less improvement of symptoms than type IVb patients had (P<0.05).

Conclusions

Pediatric PMAVF is a special subgroup of intradural arteriovenous shunt that should be treated early. Endovascular embolization is safe and effective in the treatment of pediatric PMAVFs.

Ruptured Spinal Arteriovenous Malformation: A Rare Cause of Paraplegia in Pregnancy

Background

Ruptured spinal arteriovenous malformation (AVM) is a rare cause of paraplegia in pregnancy, with only a few case reports describing complications from spinal AVMs during pregnancy in the literature.

Case

A 32-year-old woman presented at 37 weeks gestation with back pain and rapidly progressive lower limb neurological symptoms. MRI showed a previously undiagnosed spinal AVM at T8. A healthy girl was delivered by caesarean under general anaesthesia to facilitate further investigation. After spinal angiography, it was concluded the most likely aetiology was acute rupture of an intra- and perimedullary AVM with associated haemorrhage at T8 secondary to venous compression from the enlarged uterus at L5 causing high pressure within the AVM and subsequent rupture. The neurosurgical and interventional radiology teams felt the lesion was not amenable to surgical or endovascular intervention. The patient remained paraplegic with no sign of neurological recovery six months after delivery.

Conclusion

While new onset paraplegia during pregnancy secondary to ruptured spinal AVM is very rare, it is important to discuss these cases to inform future practice. In contrast to previous case reports, our patient did not spontaneously recover after delivery and was not amenable to surgical or endovascular treatment.

Embolization through the thyrocervical trunk: vascular anatomy, variants, and a case series

Background and purpose

The thyrocervical trunk (TCT) is the second ascending branch of the subclavian artery. It is considered a ‘border territory’ between interventional vascular radiology and interventional neuroradiology because it gives rise to branches both cervical and to the upper limbs. We describe the TCT branches anatomy, the most frequent variants, and expose eight endovascular procedures performed through the thyrocervical trunk.

Methods

A retrospective review of all the interventional radiology procedures carried out through the TCT in our tertiary care center from August 2014 to January 2017 is presented.

Results

A total of eight endovascular procedures through the TCT including six preoperative embolizations: three paragangliomas, a cervical vertebral metastasis, a cervical vertebral aneurysmal bone cyst, and a very rare case of nerve root extradural cervical hemangioblastoma, as well as two emergency embolizations: a patient with a cervical traumatic active bleeding hematoma and a recurrent hemoptysis in a single ventricle patient.

Conclusions

A correct knowledge of the vascular anatomy, anatomical variants, and anastomosis (especially with the anterior spinal artery) of the TCT is essential for a safe embolization, both preoperatively and on an emergency basis. In cases of recurrent hemoptysis and severe lower-neck injuries, the TCT should always be reviewed.

Concomitant conus medullaris arteriovenous shunts and sacral dural arteriovenous fistulas: pathophysiological links related to the venous drainage of the lesions in a series of five cases

Background

Spinal cord arteriovenous shunts (scAVSs) are a group of lesions located in the spinal cord itself or in the surrounding structures. The most common scAVSs are spinal dural arteriovenous fistulas (sDAVFs), which are acquired lesions. The pathogenesis of sDAVFs involves thrombosis and venous hypertension as trigger factors. Intradural scAVSs such as spinal cord arteriovenous nidus type malformations (AVMs) and pial arteriovenous fistulas are less common than sDAVFs and are considered to have a so-called ‘congenital’ origin. The association between different concomitant scAVSs is very rare and the association of sDAVFs with intradural scAVSs has been described in only a few case reports.

Methods

We describe a case series of five patients presenting with a conus medullaris AVS associated with a lower lumbar or sacral DAVF.

Results

Three of our patients were <30 years old at presentation. In four of these five cases the intradural scAVS drained caudally, engorging the epidural plexus in the same location as the sDAVF. In only one case, who presented with thrombosis of the drainage of the main compartment of a conus medullaris pial AVF, was the location of the DAVF opposite to the location of the residual drainage.

Conclusion

We discuss the pathophysiological link between scAVS and sDAVF on the basis of the rarity of the DAVF, the uncommon association between scAVS and sDAVF, the presence of sDAVF in young patients, and the venous hypertension created by the venous drainage towards the sacral area responsible for angiogenesis creating the dural shunt.

Magnetic Resonance (MR) Imaging of Vascular Malformations

Vascular malformations pose a diagnostic and therapeutic challenge due to the broad differential diagnosis as well as common utilization of inadequate or inaccurate classification systems among healthcare providers. Therapeutic approaches to these lesions vary based on the type, size, and extent of the vascular anomaly, necessitating accurate diagnosis and classification. Magnetic resonance (MR) imaging (MRI) is an effective modality for classifying vascular anomalies due to its ability to delineate the extent and anatomic relationship of the malformation to adjacent structures. In addition to anatomical mapping, the complete evaluation of vascular anomalies includes hemodynamic characterization. Dynamic time-resolved contrast-enhanced MR angiography provides information regarding hemodynamics of vascular anomalies, differentiating high- and low-flow vascular malformations. Radiologists must identify the MRI features of vascular malformations for better diagnosis and classification.

Spinal dural arteriovenous fistulas: the most frequent vascular malformations of the spinal cord

Spinal dural arteriovenous fistulas are produced by direct communication between the arterial and venous systems of the spinal cord, causing hypertension in the latter with spinal cord dysfunction. It is a rare pathology with unknown etiology and non-specific clinical symptoms that usually results in a delayed diagnosis. Often radiologists are the first to guide the disease towards an adequate diagnosis. Characteristic findings can be seen through MR or MR angiography, and may even locate the fistula in a high percentage of cases, although the pathology must be confirmed by spinal angiography. There are two treatment modalities: endovascular and surgical therapy. Endovascular treatment has improved in recent years with the advantages of a less invasive approach and is therefore usually chosen as primary therapy. In this article we review the main clinical manifestations, imaging findings and treatment of this pathology.

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.

An unusual cause of vertigo and headache in childhood

Spinal perimedullary arteriovenous fistulas (PMAVFs) are rare entities among vascular malformations of the spinal cord. Due to progressive myelopathy, spastic paresis, sensory disturbance, and bowl and bladder dysfunction can be the presenting symptoms. Cervical spinal arteriovenous fistulas (AVFs) are even rarer. These lesions differ from the ones in the thoracolumbar region and have an even wider mode of presentation. We report on a 9-year-old boy with a cervical PMAVF manifesting with headache and vertigo.

Cervical cord decompression following embolisation of a giant cervical vertebro-vertebral arteriovenous fistula

Arteriovenous fistulation between the vertebral arteries to extradural (epidural) veins, termed vertebro-vertebral arteriovenous fistulae, are uncommon diagnoses without established diagnostic algorithms or treatment options. Minimal evidence exists describing the management of this pathology. Endovascular treatment was performed under general anaesthesia by coil occlusion of the vertebral artery from the point of the fistula to the mid-vertebral artery. Repeat magnetic resonance angiographic imaging one week following the procedure confirmed an 80% reduction in the size of the epidural vein and decompression of the cervical spinal cord. At four-week follow-up there was significant qualitative improvement in the myelopathic symptoms including walking distance and pain. Normal physiological filling of the collapsed extradural vein was observed on follow-up digital subtraction angiography at five months. Catheter angiography by an experienced interventional neuro-radiologist is critical in defining the anatomy and providing minimally invasive treatment.

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.

Vascular Diseases of the Spinal Cord: Infarction, Hemorrhage, and Venous Congestive Myelopathy

Vascular pathologies of the spinal cord are rare and often overlooked. This article presents clinical and imaging approaches to the diagnosis and management of spinal vascular conditions most commonly encountered in clinical practice. Ischemia, infarction, hemorrhage, aneurysms, and vascular malformations of the spine and spinal cord are discussed. Pathophysiologic mechanisms, clinical classification schemes, clinical presentations, imaging findings, and treatment modalities are considered. Recent advances in genetic and syndromic vascular pathologies of the spinal cord are also discussed. Clinically relevant spinal vascular anatomy is reviewed in detail.

Spinal arteriovenous malformations: Is surgery indicated?

Purpose:

To identify clinico-radiological distinguishing features in various types of spinal arteriovenous malformations (AVM) with an aim to define the role of surgical intervention.

Materials and Methods:

Hero's modified Di Chiro classification differentiated four types of spinal AVMs on digital subtraction angiogram (DSA) in 74 patients: I. Dural arteriovenous fistulae (n = 35, 47.3%); II. Glomus/intramedullary (n = 13, 17.6%); III. Juvenile/metameric (n = 4, 5.4%); and, IV. Ventral perimedullary fistula (n = 21, 28.4%). A patient with extradural AVM remained unclassified. Demographic profiles, DSA features and reason for surgical referral were recorded. Statistical comparison of discrete variables like gender, spinal cord level, presentation and outcome was made using Chi-square test; and, continuous variables like age, feeder number, duration of symptoms and number of staged embolizations by one way analysis of variance with Boneferoni post hoc comparison. Embolization alone (n = 39, 52.7%), surgery alone (n = 16, 21.6%), and combined approach (n = 4, 5.4%) were the treatments offered (15 were treated elsewhere).

Results:

Type I-AVM occurred in significantly older population than other types (P = 0.01). Mean duration of symptoms was 13.18 ± 12.8 months. Thoracic cord involvement predominated in type-I and III AVMs (P = 0.01). Number of feeding arteries were 1 in 59.7%; 2 in 29.0%; and, multiple in 11.3% patients, respectively. Staged embolization procedures in type-III AVM were significant (P < 0.01). Surgical referral was required due to: Vessel tortuosity/insufficient parent vessel caliber (n = 7); residual AVM (n = 4); low flow AVM (n = 3); and, multiple feeders (n = 2). Check DSA (n = 34) revealed complete AVM obliteration in 26 and minor residual lesion in eight patients. Neurological status improved in 26 and stabilized in 25 patients.

Conclusions:

Differentiating between Type I-IV AVMs has a significant bearing on their management. Surgical intervention should be considered as an important adjunct/alternative to therapeutic embolization.

Spinal Dural Arteriovenous Fistula: A Review

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

Lumbar spinal epidural arteriovenous fistula with perimedullary venous drainage after endoscopic lumbar surgery

Spinal epidural arteriovenous fistulas (AVFs) with perimedullary venous drainage are rare. This report describes a case of lumbar epidural AVF in a patient with a history of endoscopic lumbar discectomy at the same level 8 years prior to presenting with progressive myelopathy secondary to retrograde venous reflux into the perimedullary vein. A 69-year-old man presented with progressive lower extremity weakness and sensory disturbance and loss of sphincter control 8 years after endoscopic lumbar discectomy for a disc herniation at L4-5 level. Magnetic resonance imaging showed spinal cord edema and dilated intradural perimedullary vessels. Spinal angiography revealed an epidural AVF at the site of the previous endoscopic lumbar surgery with intradural perimedullary venous drainage. The fistula was successfully occluded via endovascular transarterial embolization, and the patient had stabilization of his neurological deficits. Lumbar spinal epidural AVFs, especially those associated with iatrogenic trauma, are rare. Endoscopic surgical procedure can occlude the epidural venous plexus and disturb venous drainage, thereby inducing local venous hypertension and leading to epidural AVF with perimedullary venous drainage. This type of pathology should be considered within the differential diagnosis of delayed neurological deterioration after spinal surgery.

Intraoperative direct puncture and embolization (IOPE) using a glue material for spinal cord arteriovenous fistula: a case report

INTRODUCTION

Spinal arteriovenous fistula (AVF) is treated by embolization or surgery. However, transarterial embolization or surgery is difficult in rare cases when the fistula site is very complicated to access especially as in fistular nidus supplied by posterior and anterior spinal artery. We present the case which was treated with intraoperative direct puncture and embolization (IOPE) using glue material, since the usual transarterial or transvenous neurointerventional approach was difficult to embolize the AVF.

METHODS

A 36-year-old woman presented with progressive leg weakness and pain after a 20-year history of lower back pain. She had pelvic and spinal AVF combined with arteriovenous malformation (AVM). Despite prior treatment of the pelvic lesion with radiotherapy and coil embolization, the spinal lesion persisted and caused repeated subarachnoid hemorrhages. A spinal angiogram revealed a tortuous and long feeder of the AVF which had growing venous sac, as well as AVM. Two embolization trials failed because of the long tortuosity and associated anterior spinal artery. Four months later, drastic leg weakness and pain occurred, and IOPE was performed using a glue material.

RESULTS

The subsequent recovery of the patient was rapid. One month later, the use of a strong opioid could be discontinued, and the patient could walk with aid. A follow-up spinal angiogram revealed that the venous sac of the AVF had disappeared.

CONCLUSION

In spinal AVF which is not feasible to access by usual intervention approach and to dissect surgically, IOPE with glue material can be considered for the treatment.

Injectable chitosan thermogels for sustained and localized delivery of pingyangmycin in vascular malformations

Pingyangmycin (PYM) is an effective drug to treat vascular malformations (VM), but can easily diffuse from the injection site, which will reduce its therapeutic effect and increase side effect. Our study was to evaluate PYM-loaded chitosan thermogels for sustained and localized embolization therapy. It was shown that in vitro release of PYM thermogels could be delayed up to 12 days. The results measured by MTT assay showed that PYM thermogels could inhibit proliferation and induce apoptosis of EA.hy926 cells in a concentration and time dependent manner. In vivo pharmacokinetics study demonstrated that compared with PYM injections, PYM thermogels had a better sustained delivery of PYM. Macroscopic observation and histological examination of rabbit ear veins displayed that after administration with PYM thermogels for 18 days, obvious venous embolization and inflammatory response could be found. These results indicate that PYM thermogels is likely to achieve excellent prospects for VM treatment.

High cervical arteriovenous fistulas fed by dural and spinal arteries and draining into a single medullary vein: report of 3 cases

OBJECT

The authors previously reported a case of complex arteriovenous fistula (AVF) at C-1 with multiple dural and spinal feeders that were linked with a common medullary venous channel. The purpose of the present study was to collect similar cases and analyze their angioarchitecture to gain a better understanding of this malformation.

METHODS

Three such cases, affecting 2 males and 1 female in their 60s who had presented with hematomyelia (2) or progressive myelopathy (1), were treated surgically, and the operative findings from all 3 cases were compared using digital subtraction angiography (DSA) to determine the angioarchitecture.

RESULTS

The C-1 and C-2 radicular arteries and anterior and posterior spinal arteries supplied feeders to a single medullary draining vein in various combinations and via various routes. The drainage veins ran along the affected ventral nerve roots and lay ventral to the spinal cord. The sites of shunting to the vein were multiple: dural, along the ventral nerve root in the subarachnoid space, and on the spinal cord, showing a vascular structure typical of dural AVF, that is, a direct arteriovenous shunt near the spinal root sleeve fed by one or more dural arteries and ending in a single draining vein, except for intradural shunts fed by feeders from the spinal arteries. In 2 cases with hemorrhagic onset the drainer flowed rostrally, and in 1 case associated with congestive myelopathy the drainer flowed both rostrally and caudally. Preoperative determination of the shunt sites and feeding arteries was difficult because of complex recruitment of the feeders and multiple shunt sites. The angioarchitecture in these cases was clarified postoperatively by meticulous comparison of the DSA images and operative video. Direct surgical intervention led to a favorable outcome in all 3 cases.

CONCLUSIONS

A high cervical complex AVF has unique angioarchitectural characteristics different from those seen in the other spinal regions.

Multidisciplinary management of multiple spinal dural arteriovenous fistulae

Multiple SDAVFs are quite rare. We present two cases with double synchronous shunts and both were treated during one-stage interventional or surgical procedure. Unique images of the multiple SDAVFs as a PMAVF-like fistula were obtained. These interesting findings suggest the presence of multiple fistulas must be considered in patients being evaluated for SDAVF. A multidisciplinary approach to the management of multiple SDAVFs should depend on the anatomic location and angioarchitecture.

Filum terminale arteriovenous fistulas: the role of endovascular treatment

Object

The authors describe the clinical presentation, imaging features, and management of patients presenting with filum terminale arteriovenous fistulas (FTAVFs) and the role of transarterial treatment in their management.

Methods

The authors retrospectively reviewed data obtained in 10 patients with FTAVFs diagnosed between January 1990 and December 2011.

Results

Most patients (70%) were male, and the age of the population ranged from 31 to 72 years (mean 58.2 years). Clinical presentation was progressive paraparesis and sensory loss in the lower extremities in 9 cases, back pain in 7, radicular pain in 3, bowel/bladder disturbance in 5, and impotence in 1. The duration of symptoms varied between 2 and 24 months. Initial MRI studies showed intramedullary increased T2 signal, swollen cord, and dilated perimedullary veins in all patients. One patient had syringomyelia, presumably caused by venous hypertension transmitted by the perimedullary venous system. Embolization was attempted in 7 patients and was curative in 6 patients. Surgery was performed in the other 4 patients in whom embolization was unsuccessful or deemed not feasible. There was no treatment-related complication in either group. Symptoms, venous congestion in the cord, and syringomyelia improved on follow-up in all patients.

Conclusions

Embolization should be considered the treatment of choice for FTAVFs and can effectively treat the majority of patients presenting with an FTAVF. In a smaller group of patients in whom the angioarchitecture is unfavorable, open surgery is recommended.

Spinal ventral epidural arteriovenous fistulas of the lumbar spine: angioarchitecture and endovascular treatment

Introduction

Spinal ventral epidural arteriovenous fistulas (EDAVFs) are relatively rare spinal vascular lesions. We investigated the angioarchitecture of spinal ventral EDAVFs and show the results of endovascular treatment.

Methods

We reviewed six consecutive patients (four males and two females; mean age, 67.3 years) with spinal ventral EDAVFs treated at our institutions from May 2011 to October 2012. All patients presented with progressive myelopathy. The findings of angiography, including 3D/2D reformatted images, treatments, and outcomes, were investigated. A literature review focused on the angioarchitecture and treatment of spinal ventral EDAVFs is also presented.

Results

The EDAVFs were located in the ventral epidural space at the L1–L5 levels. All EDAVFs were supplied by the dorsal somatic branches from multiple segmental arteries. The ventral somatic branches and the radiculomeningeal arteries also supplied the AVFs in two patients. The AVFs drained via an epidural venous pouch into the perimedullary vein in four patients and into both the perimedullary vein and paravertebral veins in two patients. Four cases without paravertebral drainage were treated by transarterial embolization with diluted glue, and two cases with perimedullary and paravertebral drainages were treated by transvenous embolization alone or in combination with transarterial embolization. An angiographic cure was obtained in all patients. Clinical symptoms resolved in two patients, markedly improved in three patients, and minimally improved in one patient.

Conclusion

In our limited experience, spinal ventral EDAVFs were primarily fed by somatic branches. EDAVFs can be successfully treated by endovascular techniques selected based on the drainage type of the AVF.

Complex arteriovenous fistulas at C1 causing hematomyelia through aneurysmal rupture of a feeder from the anterior spinal artery

A 64-year-old woman presented with left occipital headache and right dissociated sensory loss due to hematomyelia on the left ventral side of C1 caused by rupture of an aneurysm on one of the feeders extending from the anterior spinal artery to complex epidural or dural and intradural arteriovenous fistulas (AVFs). Branches from the left occipital and ascending pharyngeal arteries and those from the left C2 radicular, left posterior spinal and anterior spinal arteries formed these multiple shunts, linking with a common venous drain flowing into the right petrosal vein. Surgical interception of all the shunts was achieved, making it unnecessary to directly treat the aneurysm in the spinal cord. The feeders, aneurysm and AVFs were not visualized on postoperative angiography, and the patient returned to a normal working life.

Angioarchitecture of Spinal Dural Arteriovenous Fistula - Evaluation with 3D Rotational Angiography

Purpose

The complex angioarchitecture of spinal dural arteriovenous fistulas (SDAVFs) sometimes preclude angiographic analyses or superselective procedures. Therefore, the effectiveness of 3 dimensional rotational angiography (3DRA) as a detailed imaging technique for SDAVFs was evaluated.

Materials and Methods

Of 57 patients with spinal vascular malformations, recent 13 SDAVF patients underwent 3DRA. The advantage of 3DRA compared to digital subtraction angiography (DSA) in imaging SDAVF was assessed. Angioarchitecture of SDAVF was focused on location, number, and course of feeders and draining vein. Appropriate angled views were also selected to reveal the segmental artery and feeders.

Results

3DRA technique provided additional information for imaging evaluation of SDAVFs compared to DSA; the presence of multiple feeders, including their transdural portions, as well as their courses. The contralaterally angled anterior-oblique-caudal (spider) view showed the radicular feeder by separating the intercostal artery and the dorsal muscular branch. The bottom-to-up (tunnel) view was useful for revealing the location (ventral vs. dorsal) including sharp medial turn of the dural feeder. The dual mode, which displays both vessels and bones, revealed the course of the feeders and the fistula related to the spinal bony column.

Conclusion

Because spinal vasculature overlaps in DSA, 3DRA revealed additional information for evaluations of the number and transdural course of fistular feeders in SDAVFs, and it offers working angles to obtain appropriate views.

Sacral Intradural Arteriovenous Fistula Treated Indirectly by Transection of the Filum Terminale: Technical Case Report

BACKGROUND AND IMPORTANCE:

Type A intradural arteriovenous fistulae of the sacral filum terminale are rare lesions fed primarily by the distal anterior spinal artery. The artery is frequently too narrow or tortuous for endovascular obliteration, and direct surgical resection of the fistula requires an invasive sacrectomy. We present a less invasive indirect surgical approach through an L4 laminectomy and transection of the filum terminale rostral to the fistula.

CLINICAL PRESENTATION:

A 62-year-old man presented with a 6-month history of progressive bilateral lower extremity paresthesias and weakness and associated incontinence and impotence. Spinal magnetic resonance imaging demonstrated perimedullary flow voids. Selective spinal angiography revealed a fistula at S2-3 between the distal anterior spinal artery and an early draining vein returning cranially along the filum terminale, diagnostic of an intradural arteriovenous fistula. An L4 laminectomy and transection of the filum terminale rostral to the lesion were performed to disrupt the medullary arterial supply to the intradural fistula and outflow to the medullary venous plexus of the spinal cord. At 10-month clinical follow, up the patient had regained bowel and bladder continence, was able to ambulate with a cane, and reported subjective improvement of lower extremity paresthesias. Selective spinal angiography at 1 year demonstrated no residual arteriovenous shunt.

CONCLUSION:

Pathological venous hypertension of a type A intradural arteriovenous fistula of the sacral filum terminale can be treated by transection of the filum terminale at L4. This avoids posterior partial sacrectomy required for direct resection; however, subsequent clinical follow-up is necessary to monitor for reconstitution.