Treatment of Spinal Cord Perimedullary Arteriovenous Fistula: Embolization versus Surgery

Peri-medullary anterior spinal artery aneurysm associated with cervical pial arterio-venous fistula

Spinal arteriovenous fistulas represent a heterogenous group of pathologies and are divided into four categories. Type IV fistulas are further stratified into three groups (IVa, IVb and IVc) according to the number and dimensions of the fistulous vessels. Approximately 10% of these fistulas are associated with aneurysms. However, we are not aware of a previously reported case of an aneurysm associated with a Type IVa fistula with an anterior spinal artery (ASA) feeder at the cervico-medullary junction. We therefore describe our experience with a patient presenting with a ruptured aneurysm associated with a fistula in this location.

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.

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.

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.

Remote Intramedullary Hemorrhage in the Thoracic Spinal Cord Secondary to a Perimedullary Arteriovenous Fistula of the Distal End of Conus Medullaris Mimicking Filum Terminale Arteriovenous Fistula

Perimedullary arteriovenous fistulas (PMAVFs) of the conus medullaris are rare and usually manifest with progressive myelopathy secondary to venous congestion resulting from retrograde arterialization of the draining vein into the spinal cord. We present a rare case of conus PMAVF presenting with remote intramedullary spinal cord hemorrhage in the thoracic cord. A 37-year-old woman was transferred to our institute due to sudden severe pain in the left lower leg and weakness of the lower extremities following progressive paresthesia of the lower extremities. Magnetic resonance imaging of the thoracic and lumbosacral spine revealed spinal cord congestion extending from the conus medullaris to the level of T6 with intramedullary hemorrhage at the level of T8–9 on the left side of the spinal cord. There were abnormal serpiginous intradural flow voids along the anterior surface of the spinal cord extending from the level of L2 to the lower cervical with venous varix at the level of T8–9, probably being the source of hemorrhage. Spinal angiography confirmed conus PMAVF at the distal end of the conus medullaris supplied by the sulco-commissural artery arising from the enlarged anterior spinal artery originating from the left T11 intercostal artery with cranial drainage through the dilated anterior spinal vein into the tortuous perimedullary veins up to the lower cervical level. The patient underwent successful endovascular treatment with N-butyl cyanoacrylate and had gradually improved until being ability to walk independently without residual pain of the left lower leg. We speculated that an increased venous flow into a varix may be considered an important risk factor of hemorrhage.

Filum Terminale Arteriovenous Fistula with Additional Arterial Supply by the Posterior Spinal Artery: A Report of Two Cases

Filum terminale arteriovenous fistulas (FTAVFs) are rare and usually supplied by the artery of the filum terminale, distal termination of the anterior spinal artery (ASA). These fistulas may also supply from the lateral sacral artery (LSA) arising from the internal iliac artery and/or middle sacral artery. Additional supply by the posterior spinal artery (PSA) has never been mentioned before. The authors describe two middle-aged men harboring FTAVFs manifested with progressive myelopathy and bowel/bladder dysfunction. The first fistula was supplied by the ASA with additional supply by the dilated PSA connecting with the ASA. Another fistula was supplied by the LSA and the PSA communicating with the ASA. The first case was successfully treated by endovascular treatment with N-butyl cyanoacrylate through the enlarged PSA, whereas the second case was surgically treated by direct obliteration of the fistula. Both patients had good neurological outcome.

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

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

Endovascular Management of Type III Perimedullary Spinal Arteriovenous Malformations in Pediatric Population

BACKGROUND

Spinal arteriovenous malformations (AVMs) are a cause of 20-30 of all spinal vascular malformation. The treatment option for the AVM depends upon the type of AVM. Here, we present a case series to discuss the type, management, and post-operative conclusion of the spinal AVMs.

METHOD

Four patients with spinal AVMs were retrospectively reviewed. All 4 patients were with a nidus-type AVM. Treatment for all patients required embolization. Clinical features, imaging, treatment, and clinical results were observed. All 4 patient's clinical outcome was assessed using the Modified Ranked Scale.

RESULT

The follow-up after management showed that all four-patient recovered without any residual deficit. All four-patient scored zero (0) on the Modified Ranked Scale.

CONCLUSION

Pediatric spinal AVMs are rare and require complex multimodal approach to achieve favorable outcomes.

Anterior Approach Combined with Endoscopic Fluorescence Video Angiography for a Cervical Perimedullary Arteriovenous Fistula

BACKGROUND

Perimedullary arteriovenous fistulas (pAVFs) of the anterior cervical spinal cord are rare and difficult to eradicate by surgery because of the limitations of the approach routes. Because of the anatomic relationships, an anterior approach with corpectomy can provide direct observation. However, a narrow corridor to the lesion is the drawback of this approach. Therefore, to overcome this limitation, we introduced angled endoscopes integrated with fluorescence video angiography to observe the real-time blood flow.

CASE DESCRIPTION

A 47-year-old woman was incidentally found to have a pAVF fed by multiple radicular arteries, and she underwent direct surgery via the anterior approach. Although observation of the entire lesion was difficult with the microscope alone, the introduction of the angled endoscope made it possible to observe the lateral portion of the spinal cord hidden behind the dura mater. Furthermore, endoscopic fluorescein video angiography visualized residual fine feeding arteries that were then electrocoagulated, which contributed to complete obliteration of the shunt.

CONCLUSIONS

The anterior approach with endoscopic assistance is a reasonable strategy for the treatment of ventrally located cervical pAVFs. Furthermore, integration of a fluorescence video angiography system with the endoscope enables confirmation of the complicated real-time hemodynamics of the pAVFs, contributing to reliable treatment.

Filum Terminale Arteriovenous Fistula in Association with Degenerative Lumbosacral Spinal Canal Stenosis: Report of 3 Cases and Review of the Literature

BACKGROUND

Filum terminale arteriovenous fistulas (FTAVFs) are rare, and the pathogenesis of these fistulas remains unclear. They may be either congenital or acquired in origin. The authors report 3 cases of FTAVFs in association with severe spinal canal stenosis. The authors also review literature of FTAVFs associated with spinal canal stenosis.

CASE DESCRIPTION

All 3 cases harboring FTAVFs manifested with progressive myelopathy and bowel/bladder dysfunction following long history of back pain, sciatica, and/or intermittent claudication. The fistulas were located around or at the level of spinal canal stenosis and supplied by the anterior spinal and/or lateral sacral arteries with cranial drainage from the dilated vein of the filum terminale to the perimedullary veins. The first and third cases were treated concomitantly by performing instrumented fusion with decompressive laminectomy along with occlusion of the fistula with good results. The second case was unsuccessfully treated by endovascular treatment through the lateral sacral artery and denied further surgical treatment.

CONCLUSIONS

Our 3 case reports may provide additional evidence supporting an acquired etiology of FTAVFs, probably secondary to the severe central canal stenosis. From our review, the level of the fistulas in most patients is correlated with the level of spinal canal stenosis. The authors preferred the concomitant surgical treatment by performing decompressive laminectomy and obliteration of the fistula in the same surgical session.

Spinal Vascular Malformations: Treatment and Outcome

BACKGROUND

Vascular malformations of the spinal cord are a rare and complex clinical entity and can lead to severe morbidity with progressive spinal cord symptoms if not treated properly. In early stages, the disease is characterized by slowly progressive, nonspecific symptoms, such as gait disturbance, paresthesia, diffuse sensory symptoms, and radicular pain; in the late stages, bowel and bladder incontinence, erectile dysfunction, and urinary retention may develop. In recent decades, understanding and treatment of spinal vascular malformations have improved with the evolution of diagnostic tools and treatment modalities; however, it is still difficult to manage these cases because of the complexity of the pathology. The aims of this study were to present the long-term outcomes of our patients and to discuss the optimal management strategies.

METHODS

We reviewed the records of 78 patients with spinal vascular malformations and performed a retrospective, single-center case series evaluating initial occlusion, recanalization, retreatment, and neurologic status of patients with dural arteriovenous fistulas, perimedullary arteriovenous fistulas, arteriovenous malformations, and extradural arteriovenous fistulas who had undergone embolization and/or surgery.

RESULTS

No mortality was observed. Complete obliteration was achieved in 76 patients (97.4%).

CONCLUSIONS

Both endovascular and surgical treatment of spinal vascular malformations resulted in significant long-term recovery from myelopathic symptoms and improvement in quality of life for most patients.

Intracranial subarachnoid hemorrhage resulting from non-cervical spinal arteriovenous lesions: Analysis of possible cause of bleeding and literature review

Subarachnoid hemorrhage (SAH) or intraventricle hemorrhage (IVH) with negative cerebral digital subtraction angiography (DSA) results, which are due to non-cervical spinal arteriovenous lesions, are uncommon. In this article we presented three cases from our hospital and nineteen cases from prior published literature and discussed clinical features, possible mechanisms underlying the hemorrhage and therapeutic strategies for managing this unusual entity. Our analysis revealed that headache was the most common initial symptom. Almost 60% of patients had symptoms related to the spinal cord at admission. Intramedullary arteriovenous malformations (AVM) were the most common type of malformation, and the thoracic segment was the most common location of the non-cervical spinal arteriovenous lesions. More than half of the patients had additional aneurysms. Surgery was chosen as the primary treatment modality in this series. Therefore, we speculate that thoracolumbar spinal arteriovenous lesions are an unusual cause of intracranial SAH with negative cerebral DSA results. If non-cervical spinal AVMs were associated with DSA-negative SAH, the pattern of hemorrhage could be manifested as the blood in supratentorial cisterns, the fourth ventricle or no copious blood around the foramen magnum as well (somewhat paradoxically), it depends on the timing of detection and image evaluation. The formation and the rupture of associated aneurysms were the most likely immediate cause of the intracranial SAH. If non-cervical spinal AVMs were not associated with DSA-negative SAH and all cases were genuine cases of 'SAH-of-unknown origin', the spinal AVM could be considered as incidental finding. Magnetic resonance imaging (MRI) of the complete spinal neuraxis is recommended to either exclude or identify a spinal lesion in these patients. Catheter-based spinal angiography remains the gold standard for the diagnosis of spinal vascular diseases. The decision regarding a therapeutic strategy is based on the angioarchitecture and on the type of spinal arteriovenous lesions.

Study and therapeutic progress on spinal cord perimedullary arteriovenous fistulas

Spinal cord perimedullary arteriovenous fistulas (PMAVFs) are rare and belong to type IV spinal cord arteriovenous malformations (AVMs). Little is known regarding the treatment and prognosis of spinal cord PMAVFs. In the present study the relevant literature from PubMed was reviewed, and it was found that these fistulas can occur at all ages but are more common in children. In children, most spinal cord PMAVFs are large and with high flow, begin with bleeding and are frequently associated with hereditary hemorrhagic telangiectasia. However, in adults, most spinal cord PMAVFs are small and with low flow and begin with progressive spinal cord dysfunction. The early diagnosis of spinal cord PMAVFs is generally difficult, and symptoms can be very severe at the time of diagnosis. Digital subtraction angiography remains the gold standard; however, computed tomography angiography and magnetic resonance angiography are also promising. Spinal cord PMAVFs can be treated by endovascular embolization, surgical removal or a combination of the two methods. Most spinal cord PMAVFs show good outcomes after the appropriate treatment, and the prognosis is primarily associated with the blood flow of the PMAVF. For high-flow spinal cord PMAVFs, endovascular embolization is more effective and can lead to a good outcome; however, for low-flow spinal cord PMAVFs, surgical removal or the combination with endovascular embolization is the optimal choice. The prognosis for low-flow types is slightly worse than for high-flow spinal cord PMAVFs in children, but the outcome is acceptable.

Spinal arteriovenous fistulas in adults: Management of a series of patients treated at a neurology department

OBJECTIVE

Spinal arteriovenous fístulas (SAVF), a rare type of vascular malformation, account for 3% of all spinal cord lesions. Without early treatment, the associated morbidity is high; furthermore, SAVF pose a major diagnostic challenge. Our purpose was to evaluate the clinical characteristics of SAVF and review their progress after treatment to determine whether it may be too late for treatment in some cases.

METHODS

We present a retrospective series of 10 patients diagnosed with SAVF and treated at a tertiary hospital during a 3-year period.

RESULTS

In our sample, SAVF were found to be significantly more frequent in men (80%). Mean age in our sample was 65.4 years. The most common initial symptom was intermittent claudication/paraparesis (70%). In most patients, symptoms appeared slowly and progressively. At the time of diagnosis, the most common symptoms were motor, sensory, and sphincter disorders. Mean time from symptom onset to diagnosis was 24.3 months. Initial diagnosis was erroneous in 60% of the patients. Spinal MRI was diagnostic in 90% of these cases and arteriography in 100%. The most common location of the fistula was the lower thoracic region and the most frequent type was dural (7 cases). All patients were treated with embolisation, surgery, or both and 70% improved after fistula closure regardless of progression time.

CONCLUSIONS

Diagnosis of SAVF is difficult and often delayed, which leads to poorer patient prognosis. We should have a high level of suspicion for SAVF in patients with intermittent claudication or paraparesis exacerbated by exercise. Early treatment should be started in these patients. Treatment should always aim to improve quality of life or stabilise symptoms, regardless of progression time.

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.

Surgical and Endovascular Treatment for Spinal Arteriovenous Malformations

Spinal arteriovenous malformation (AVM) is a broad term that constitutes diverse vascular pathologies. To date, various classification schemes for spinal AVM have been proposed in literature, which helped neurosurgeons understand the pathophysiology of the disease and determine an optimal treatment strategy. To discuss indications and results of surgical and endovascular interventions for spinal AVM, this article refers to the following classification proposed by Anson and Spetzler in 1992: type I, dural arteriovenous fistula (AVF); type II, glomus intramedullary AVM; type III, juvenile malformations; and type IV, perimedullary AVF. In general, complete obliteration of the fistula is a key for better outcome in type I dural and type IV perimedullary AVFs. On the other hand, in type II glomus and type III juvenile malformations, functional preservation, instead of pursuing angiographical cure, is the main goal of the treatment. In such cases, reduction of the shunt flow can alleviate clinical symptoms. Proper management of spinal AVM should start with neurological examination and understanding of angioarchitectures, which provide critical information that guides the indication and modality of intervention. Finally, close collaboration of the microsurgical and endovascular teams are mandatory for successful treatment.

Influence of indocyanine green angiography on microsurgical treatment of spinal perimedullary arteriovenous fistulas

OBJECTIVE

The microvascular anatomy of spinal perimedullary arteriovenous fistulas (AVFs) is more complicated than that of dural AVFs, and occlusion rates of AVF after open microsurgery or endovascular embolization are lower in patients with perimedullary AVFs (29%–70%) than they are in those with dural AVF (97%–98%). Reports of intraoperative blood flow assessment using indocyanine green (ICG) video angiography in spinal arteriovenous lesions have mostly been for spinal dural AVFs. No detailed reports on spinal perimedullary AVFs are available.

METHODS

Participants were 11 patients with spinal perimedullary AVFs (Type IVa in 5 patients, Type VIb in 4, and Type IVc in 2). Intraoperative ICG video angiography was assessed by measuring the number of cases in which this modality was judged essential by the surgeon to correctly occlude the fistula.

RESULTS

In all patients, arterial feeders were identified and intravenous ICG video angiography was performed before and after blocking the feeders. In one patient, selective intraarterial ICG video angiography was also performed. The findings provided by ICG video angiography significantly changed the surgical procedure in 4 of 11 patients (36%). Postoperatively, complete occlusion of the AVF was achieved in 10 of the 11 patients (91%).

CONCLUSIONS

Intraoperative ICG video angiography can have a significant impact on deciding surgical strategy in the microsurgical treatment of spinal perimedullary AVF.

Cervical perimedullary arteriovenous shunts: a study of 22 consecutive cases with a focus on angioarchitecture and surgical approaches

BACKGROUND

Reports of cervical perimedullary arteriovenous shunt (PMAVS) are limited, and treatment strategies have not been established.

OBJECTIVE

To describe angioarchitecture and optimal treatment strategies for cervical PMAVS.

METHODS

We treated 22 patients with cervical PMAVS between 2000 and 2012 (8 women and 14 men; age, 9-80 years). According to the classification, our patients included type IVa (4 patients), type IVb (16 patients), and type IVc (2 patients). Seventeen patients presented with subarachnoid hemorrhage.

RESULTS

A total of 41 shunting points were localized in 22 patients, of which 34 points were located ventral or ventrolateral to the spinal cord. The anterior spinal artery (ASA) contributed to the shunts in 16 patients. Aneurysm formation was identified in 8 patients. Endovascular treatment was attempted in 3 patients, resulting in complete obliteration in 1 patient (type IVc). Overall, 21 patients underwent open surgery. An anterior approach with corpectomy was elected for 2 patients; the other 19 patients underwent the posterior approaches using indocyanine green videoangiography, intraoperative angiography, endoscopy (8 patients), and neuromonitoring. Twenty patients were rated as having a good recovery at 6 months after surgery. No recurrence was observed in any patients during the follow-up (mean, 59.7 months).

CONCLUSION

Shunting points of the cervical PMAVS were predominantly located ventral or ventrolateral to the spinal cord and were often fed by the ASA. Even for ventral lesions, posterior exposure assisted with neuromonitoring and endoscopy, and intraoperative angiography provided a view sufficient to understand the relationships between the shunts and the ASA and contributed to good surgical outcomes.

Surgical management of combined intramedullary arteriovenous malformation and perimedullary arteriovenous fistula within the hybrid operating room after five years of performing focus fractionated radiotherapy: case report

Perimedullary arteriovenous fistula (AVF) shunts occur on the spinal cord surface and can be treated surgically or by endovascular embolization. In contrast, the nidus of an intramedullary arteriovenous malformation (AVM) is located in the spinal cord and is difficult to treat surgically or by endovascular techniques. The benefits of radiotherapy for treating intramedullary AVM have been published, but are anecdotal and consist largely of case reports. We present a case of combined cervical intramedullary AVM and perimedullary AVF which received surgical treatment within a hybrid operating room (OR) after 5 years of focus fractionated radiotherapy. A 37-year-old male presented with stepwise worsening myelopathy. Magnetic resonance imaging and spinal angiography revealed intramedullary AVM and perimedullary AVF at the C3 to C5 levels. In order to reduce nidus size and blood flow, we first performed focal fractionated radiotherapy. Five years later, the lesion volume was reduced. Following this, direct surgery was performed by an anterior approach using corpectomy in the hybrid OR. The spinal cord was monitored by motor-evoked potential throughout the surgery. Complete obliteration of the fistulous connection was confirmed by intraoperative indocyanine green video-angiography and intraoperative angiography, preserving the anterior spinal artery. We conclude that surgical treatment following focal fractionated radiotherapy may become one strategy for patients who are initially deemed ineligible for endovascular embolization and surgical treatment. Furthermore, the hybrid OR enables safe and precise treatment for spinal vascular disorders in the fields of endovascular treatment and neurosurgery.

Management of spinal dural arterio-venous fistulas. Report of 12 cases and review of literature

INTRODUCTION

Spinal cord arteriovenous malformations and fistulae are rare vascular lesions than can lead to myelopathy that is at many instances overlooked during diagnosing the cause of progressive myelopathy and weakness. Treatment options involve either endovascular embolization, surgical disconnection or a combination of both. This study aims to evaluate various treatment methods for sDAVFs and the outcome of these methods.

METHODS

This study involved 12 patients suffering from symptoms attributed to spinal dural arteriovenous fistulas; 11 were male and one was a female patient, with ages ranging between 50 years and 71 years. All patients presented with progressive spastic paraparesis of varying grades, and 6 had sphincter disturbances prior to treatment. Patients were evaluated by Aminoff-Logue motor disability scale.

RESULTS

Three were managed by endovascular embolization and 9 by surgical disconnection. Three patients showed full recovery after treatment, 7 patients showed no change in their neurological status following treatment, and 2 patients showed partial recovery after treatment.

CONCLUSION

Spinal AVF is a rare curable cause of spinal myelopathy if managed promptly. Good angiographic studies prior to treatment decision are a must, in order to plan the best approach according to the angioarchitecture of the fistula whether it will allow endovascular embolization or will surgery be more feasible.

Endovascular treatment in spinal perimedullary arteriovenous fistula

This study includes 20 patients with 21 spinal perimedullary fistulae. There were nine Type IVa (42.8%) lesions, ten Type IVb (47.6%) and two Type IVc (9.5%) lesions. The dominant arterial supply was from the anterior spinal artery (47.6%), posterior spinal artery (19%) and directly from the radiculomedullary artery (28.5%). Sixteen lesions in 15 patients were treated by endovascular route using n-butyl-2-cyanoacrylate. Endovascular treatment was not feasible in five patients. Of the ten patients with microfistulae, catheterization failed/was not attempted in 40%, complete obliteration of the lesion was seen in 60% but clinical improvement was seen in 40% of patients. Catheterization was feasible in all ten patients with macrofistulae (nine type IVb and two type IVc lesions). Complete obliteration of the lesions was seen in 60% and residue in 30%. Clinical improvement was seen in 80% and clinical deterioration in 10%. In conclusion, endovascular glue embolization is safe and efficacious in type IVb and IVc spinal perimedullary fistulae and should be considered the first option of treatment. It is also feasible in many of the type IVa lesions.

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

Object

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

Methods

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

Results

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

Conclusions

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

Traumatic spinal perimedullary arteriovenous fistula due to knife stabbing and subsequent kyphosis: case report

Perimedullary arteriovenous fistula (AVF) is a relatively rare spinal vascular malformation. Although it has traditionally been considered to be a congenital lesion, some cases identified in adults have suggested that the lesion may be acquired. The etiology and exact mechanism of these lesions are unknown. The authors present a case of a perimedullary AVF caused by a direct stabbing injury of the spinal cord and induced by subsequent kyphosis, and they discuss the pathogenesis and treatment strategy.

Clinical results after the multidisciplinary treatment of spinal arteriovenous fistulas

PURPOSE

We retrospectively evaluated the clinical outcome after multidisciplinary treatment of spinal arteriovenous fistulas (AVFs) in terms of the Aminoff-Logue grading scale (ALS) to depict the outcome in a perspective pertinent to the quality of everyday living.

MATERIALS AND METHODS

Twenty-six spinal AVFs in 25 patients were angiographically diagnosed from April 1998 through April 2012 and treated by endovascular embolization or surgery. When both treatment procedures seemed feasible, embolization was undertaken as the initial treatment. Motor and gait disturbance at follow-up was retrospectively graded according to ALS.

RESULTS

All lesions were localized at the thoracolumbar or sacral levels and include six epidural AVFs with intradural venous reflux, 14 dural AVFs, and six perimedullary AVFs. Embolization was performed as the initial treatment for 17 lesions, while open surgery was performed for the others as well as for residual or recurrent lesions after embolization. All lesions were completely occluded except three perimedullary AVFs. At clinical follow-up of 1-153 months (mean 53.3), amelioration of gait disturbance with reduction of ALS scores was noted for 13 lesions and amelioration of micturition for 13 lesions as well.

CONCLUSION

Clinical functional status was improved for half of the lesions after the multidisciplinary treatment.

Vascular diseases of the spinal cord

Vascular disease affecting the spinal can cause substantial neurologic morbidity. Several vascular spinal cord ailments present as neurologic emergencies, and should thus be recognizable to the practicing neurologist. We review the epidemiology, presentation, management strategies, and prognosis of various pathologies, including infarction, dural arteriovenous fistula, arteriovenous malformation, cavernous malformation, compressive epidural hematoma, vasculitis, and genetic abnormalities.

Spinal Pial (Type IV) Arteriovenous Fistulae

BACKGROUND:

Demographics, hemorrhage risk, and results of surgical and endovascular treatment of spinal pial (type IV) arteriovenous fistulae (AVFs) across a large patient group have not been previously reported.

OBJECTIVE:

To report demographics, hemorrhage rates, and treatment results for these AVFs.

METHODS:

We performed a pooled analysis via the PubMed and Embase databases through November 2012. Individualized patient data were extracted and analyzed using Cox proportional hazards regression to obtain hazard ratios for hemorrhage risk factors and pooled for baseline demographics and treatment results.

RESULTS:

We extracted information on 213 patients from 28 studies. Only 1% of lesions were incidental; 93% of patients presented with neurologic deficits and 36% with hemorrhage. Patients with type IVa lesions were significantly older (mean age, 46.9 years) and demonstrated a male sex predilection (68% male). Patients with type IVc lesions were significantly younger (mean age, 18.7 years), had no sex predilection, and had the highest prevalence of syndromic conditions (29% of cases). The annual hemorrhage rate was 2.5% (95% confidence interval [CI]: 1.4%-4.7%), increasing to 5.6% for hemorrhagic fistulae (95% CI: 3.0%-10.7%; hazard ratio: 6.31; 95% CI: 0.69-57.4; P = .10). Patient sex, fistula location, and fistula subclass were not significant risk factors for hemorrhage. The surgical obliteration rate was 88%; 68% of patients improved, 26% were the same, and 6% were worse. The endovascular obliteration rate was 74%; 75% of patients improved, 14% were the same, and 11% were worse.

CONCLUSION:

We demonstrate the utility of the Anson-Spetzler a-c subclassification and underscore the efficacy of surgical and endovascular spinal AVF treatment.

Arteriovenous fistula and pseudoaneurysm of the anterior spinal artery caused by an epidural needle in a 5-year-old patient

Authors present the case of a 5-year-old patient with a spinal arteriovenous fistula (AVF) and pseudoaneurysm of the anterior spinal artery (ASA) caused by a traumatic epidural needle stick injury. A discussion and relevant review of the literature follow. The boy had a remote history of a liver transplant and required neuraxial blockade for an unrelated abdominal surgical procedure. Initial insertion of the epidural needle at the T9-10 interspace yielded blood. A second attempt at T10-11 was successful. Delayed left leg weakness developed on postoperative Day 8, with an MR image showing a track injury through the cord and a ventral subarachnoid hematoma. Laminectomies from T-9 to T-11were performed emergently to decompress the spinal cord. The dura mater was opened, the ventral hematoma was evacuated, and brisk venous bleeding was controlled with cauterization. Postoperative spinal angiography demonstrated an AVF and pseudoaneurysm of the ASA. Repeat angiography at postoperative Week 4 demonstrated complete resolution of the AVF and pseudoaneurysm, probably due to intraoperative cauterization of the draining vein. The patient underwent a short course of rehabilitation and had no clinical or electrophysiological evidence of spinal cord damage at the 20-month follow-up. One should be cognizant of the possibility of a cord injury in a patient with new-onset neurological deficits following an interventional spine procedure. Neuroimaging is essential for prompt diagnosis and treatment.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Perimedullary arteriovenous fistulas in children: report on six cases

BACKGROUND

Perimedullary arteriovenous fistulas (PMAVFs) are rare spinal lesions and even more uncommon in children.

OBJECTIVE

The aim of this study was to document rare occurrences of this type of arteriovenous malformation in six children treated at our institution.

METHODS

The clinical data, radiological findings, and treatment in six cases of PMAVFs were reviewed. Six patients with PMAVFs were managed at our institution over a 5-year period. The patients (four girls and two boys), ranging in age from 6 to 15 years, presented with initially fluctuating, and eventually permanent and progressive, sudden-onset paraparesis, sensory disturbances, and sphincter dysfunction. The duration of symptoms before diagnosis ranged from 1 week to 13 years.

RESULTS

All the patients underwent magnetic resonance imaging and spinal selective angiography, which demonstrated the characteristic imaging of an arteriovenous fistula. Embolization of the arteriovenous fistula was initially attempted in three patients with successful occlusion of the fistula in two. For the remaining cases, open surgery was performed, with complete occlusion of the fistula. There was no morbidity, regardless of the treatment performed. All the patients experienced neurological improvement after treatment.

CONCLUSIONS

No specific clinical or radiological characteristic of PMAVFs in the pediatric population was observed when our series was compared with a general series. Early diagnosis and timing of the therapeutic intervention seemed to avoid the development of irreversible ischemic myeloradiculopathy and prevented hemorrhage. Treatment for PMAVFs is difficult to standardize because these are extremely rare lesions with different angioarchitecture configurations.

Endovascular Treatment of Cervical Giant Perimedullary Arteriovenous Fistulas

BACKGROUND

Giant perimedullary arteriovenous fistulas (GPMAVFs) located in the cervical region are a rare pathology with distinctive characteristics.

OBJECTIVE

To evaluate clinical presentation and different endovascular treatment options of cervical GPMAVFs and review previously published data in the literature regarding cervical GPMAVFs.

METHODS

Six patients with cervical GPMAVFs were found in the spinal vascular malformations database of our group collected between 1990 and 2009. Endovascular techniques and treatment outcomes were evaluated and compared with other published series.

RESULTS

Clinical presentations were progressive motor deficit (5 patients), hematomyelia (1 patient), meningeal syndrome (1 patient), and respiratory arrest and gait apraxia (1 patient). Three patients were treated by the transarterial approach. One patient was treated by the transvenous approach due to previous embolizations resulting in a proximal occlusion and preventing a safe transarterial approach. A transvenous approach was used in another patient due to complex arterial anatomy. In 1 patient, direct percutaneous puncture of the venous pouch was necessary because of previous proximal occlusion of the arteries. All embolizations resulted in complete occlusions with clinical improvement, and there was no recanalization during a mean follow-up of 21 months.

CONCLUSION

Transarterial embolization of cervical GPMAVFs is safe and effective when it is done in highly experienced centers. Cervical GPMAVFs that cannot be accessed by the transarterial technique due to their complex angioarchitecture can be treated by transvenous embolization or direct puncture of the venous pouch.

Pediatric high-flow, cervical spinal, macro-arteriovenous fistula, treated with the endovascular cotton candy glue injection technique

A 3-year-old boy presented to our hospital with progressive neurological deficits. Spinal magnetic resonance imaging (MRI) revealed a perimedullary macro-arteriovenous fistula (PMAVF) resulting in a large venous pouch within the parenchyma of the lower cervical spinal cord. Transarterial varix embolization of the fistula from the venous side was performed using N-butyl cyanoacrylate with tantalum powder. Postembolization angiography confirmed obliteration of the fistula, and MRI revealed thrombosis and reduction in size of the venous component. The patient's clinical symptoms were reduced dramatically following the intervention, and no neurological complications occurred due to the treatment. The prognosis of spinal PMAVF depends primarily on the presence of medullar signs and symptoms and on time to treatment. The volume of the venous pouch after the intervention was markedly reduced, and complete clinical recovery was obtained. Urgent endovascular intervention, as seen in this case, is considered first-line therapy and aims to decrease the risk of neurological sequela.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Endovascular treatment of spinal arteriovenous lesions: beyond the dural fistula

During the past few decades, there have been significant advances in the understanding of spinal vascular lesions, mainly because of the evolution of imaging technology and selective spinal angiography techniques. In this article, we discuss the classification, pathophysiology, and clinical manifestations of spinal vascular lesions other than DAVFs and provide a review of the endovascular approach to treat these lesions.

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

OBJECTIVE

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

CLINICAL PRESENTATION

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

TECHNIQUE

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

CONCLUSION

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

Direct percutaneous venous puncture and embolization of giant perimedullary arteriovenous fistulas

PMAVFs are rare entities that are formed by a direct communication between an artery that feeds the spinal cord and a vein. The goal of treatment is to occlude the shunt; this is done endovascularly either from an arterial or a venous approach. When these approaches are not possible, direct percutaneous puncture of the draining veins may be attempted to embolize the arteriovenous shunt directly.

Endovascular management of spinal vascular malformations: history and literature review

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