Concomitant conus medullaris arteriovenous malformation and sacral dural arteriovenous fistula of the filum terminale

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.

Sacral dural arteriovenous fistula of the filum terminale coexisting with partially thrombosed filum vein: A case report and literature review

Background:

Filum terminale arteriovenous fistulas (FTAVFs) are rare and usually classified as intradural ventral AVFs or Type IVa perimedullary fistulas, located on the pia surface along the course of filum terminale internum (FTI). We report an extremely rare case of sacral dural arteriovenous fistula of the FT. We also review the occurrence of FTAVFs in the sacral region.

Case Description:

A 64-year-old man presented with progressive weakness of the lower extremities for 3 months and bowel/bladder dysfunction following long history of back pain radiating to both legs. Magnetic resonance imaging of the lumbosacral and thoracic spine showed spinal cord congestion, extending from the conus medullaris to the level of T3, and partial thrombosis within the abnormal tortuous and dilated flow void, running from the sacral area to conus medullaris. Further findings were compression fracture of L2 vertebra, Grade I degenerative spondylolisthesis at the level of L2-3, and L3-4, and spinal stenosis at L2-3, L3-4, and L4-5. Spinal angiography, maximum intensity projection reformatted image of angiographic computerized tomography, and three-dimensional reconstructed image clearly demonstrated dural AVF of the FT at the level of S2 supplied by bilateral lateral sacral and middle sacral arteries with cranial drainage to perimedullary vein through the enlarged vein of the filum. The patient was indirectly treated by transection of the filum terminale and the draining vein at the level of L5 rostral to the fistula.

Conclusion:

Sacral DAVFs of the FT are extremely rare. In our case, the formation of fistula may cause by venous hypertension secondary to partial thrombosis within the filum vein, probably resulting from long-standing spinal canal stenosis. Sacral FTAVFs may be found on the pia surface of the terminal FTI, dural component at the area of dural sac termination, or dural extension covering the filum terminale externum.

Cauda equina arteriovenous fistula supplied by proximal radicular artery and concomitant sacral dural arteriovenous fistula: A case report and literature review

Background

Cauda equina arteriovenous fistulas (AVFs) fed by the proximal radicular artery are exceedingly rare. Spinal dural arteriovenous fistulas (DAVFs) in the sacral region are rare and usually misdiagnosed. We report a case of a cauda equina AVF with concomitant sacral DAVF. We also review the coexistence of multiple types of spinal vascular malformations in a single patient.

Case Description

A 54-year-old man presented with progressive weakness of the lower extremities for 1 month. Magnetic resonance imaging (MRI) of the lumbosacral and thoracic spine showed spinal cord congestion, extending from the conus medullaris to the level of T7, and abnormal tortuous and dilated flow void, running from the level of L5 to T12 along anterior surface of the spinal cord. Spinal angiography demonstrated the fistula at the level of L2 below the conus medullaris. Based on intraoperative findings, the cauda equina AVF supplied by the proximal radicular artery with cranial drainage through the enlarged radicular vein was confirmed and successfully obliterated. Another enlarged arterialized radicular vein running parallel to another cauda equina nerve root is observed with unknown origin. After the operation, the patient showed mild improvement of his symptoms. Follow-up MRI and contrast-enhanced MR angiography revealed an another sacral DAVF vascularized by the lateral sacral artery.

Conclusion

The coexistence of different spinal vascular malformations in a same patient is extremely rare. Most authors of several studies hypothesized that venous hypertension and thrombosis due to the presence or treatment of the first spinal vascular lesion may produce a second DAVF.

Concomitant Sacral Dural Arteriovenous Fistula and Conus Medullaris Arteriovenous Malformation with Respective Drainage Veins: Case Report and Literature Review

BACKGROUND

Spinal dural arteriovenous fistulas (DAVFs) and spinal arteriovenous malformations (AVMs) are relatively rare. Moreover, multiple spinal cord vascular lesions in an individual, such as double DAVFs and DAVF with AVM, are extremely rare. To date, there are only several reported cases of concomitant spinal DAVFs and AVMs.

CASE DESCRIPTION

A 25-year-old woman presented with pain of the right lower limb persisting for 1 month. Spinal magnetic resonance imaging showed prominent signal flow voids in the lumbosacral canal. Spinal digital subtraction angiography (DSA) showed a sacral DAVF fed by the right lateral sacral artery and a spinal intradural AVM at the conus medullaris fed by the anterior spinal artery from the left T11 intercostal artery. The drainage veins in these 2 lesions were respective and without common anastomosis. The diagnosis of concomitant sacral DAVF and conus AVM was made. Microsurgery was performed to excise these lesions successfully in the same operation. The patient's symptoms gradually improved after surgery. Postoperative spinal DSA confirmed the complete disappearance of the 2 lesions.

CONCLUSIONS

The concomitant presence of sacral DAVF and conus AVM is extremely rare. Nonetheless, clinicians should be aware of the possibility of the coexistence of multiple types of spinal vascular lesions in a single patient.

Case of Cowden Syndrome with 15 Spinal Arteriovenous Fistulas

BACKGROUND

Spinal vascular malformations are rarely multiple: fewer than 50 observations have been documented so far, with a maximum of 4 coexisting lesions per patient, always restricted to a single vertebral region (e.g., cervical or thoracic).

CASE DESCRIPTION

We describe the case of a 61-year-old woman with Cowden syndrome with 15 spinal arteriovenous fistulas (AVFs) at the cervical, thoracic, and lumbar levels and an adrenal AVF. She was initially referred for reevaluation of an upper cervical spinal epidural spinal arteriovenous fistula diagnosed 6 years earlier. Her history included breast carcinoma, a malignant salivary gland tumor, and removal of multiple ovarian, thyroid, and gastric hamartomas. Computed tomography and magnetic resonance imaging confirmed the presence of a prominent cervical vascular lesion. Spinal digital subtraction angiography revealed the presence of 15 additional vascular anomalies.

CONCLUSIONS

This multiplicity of AVFs appears to result from a combination of various factors including local regional hemodynamic changes, growth factor-mediated alterations involving notably vascular endothelial growth factor pathways, and the prothrombotic state associated with abnormalities in blood vessel structure.

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.

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.

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.

Arteriovenous fistulae of the filum terminale

Filum terminale arteriovenous fistulae are a rare type of arteriovenous shunt generally characterized by a single direct communication between the artery of the filum terminale and a single draining vein. These intradural arteriovenous shunts are three times more common in men than women (mean age 55 years). Symptoms are related to venous congestion, vascular hypertension, and a putative chronic steal phenomenon which result in spinal cord ischemia and myelopathy. Interestingly, hemorrhage has never been reported as a mode of presentation. MRI demonstrates increased flow voids and T2 changes involving the conus and the lower spinal cord, and these findings are not dissimilar from those seen with the more common type 1 spinal dural arteriovenous fistulae. Thus conventional spinal angiography is necessary for a definitive diagnosis and to localize exactly the site of the fistula. Both surgical interruption of the fistula and endovascular embolization are safe and effective therapeutic modalities. However, because of the very small caliber of the feeding artery, endovascular therapy is often not feasible; and thus, surgery remains the method more commonly utilized for their treatment. Definitive treatment consists of obliteration of the direct arteriovenous shunt. In this review, we describe the anatomy, pathophysiology, clinical presentation, imaging, and treatment options of these less common intradural arteriovenous shunts.

Concomitant Lumbosacral Perimedullary Arteriovenous Fistula and Spinal Dural Arteriovenous Fistula

BACKGROUND

Although multifocal spinal arteriovenous malformations (AVMs) have been reported before, the present case is the first case of 2 different types, including 1 perimedullary arteriovenous fistula and 2 spinal dural arteriovenous fistulas of lumbosacral AVMs, coexisting in 1 patient. We also report the use of hybrid techniques in treatment of concomitant lumbosacral spinal AVMs.

CASE DESCRIPTION

A 65-year-old man presented with a 4-year history of progressive sensory, motor, and sphincter dysfunction. Spinal magnetic resonance imaging and digital subtraction angiography showed 2 spinal dural arteriovenous fistulas (fed by the right L2 lumbar artery and the right lateral sacral artery, respectively) and 1 perimedullary arteriovenous fistula (fed by the filum terminale artery from the left L2 lumbar artery [i.e., filum terminale arteriovenous fistulas]. A hybrid technique was used to perform embolization of the right L2 spinal dural arteriovenous fistula and microsurgery of the L5 level filum terminale vein. The patient was asymptomatic 1 year later.

CONCLUSIONS

Multifocal spinal vascular malformations may coexist in 1 case, and standardized spinal digital subtraction angiography, including the bilateral internal iliac arteries and median sacral artery, should be performed to avoid a missed diagnosis. The concomitant phenomenon indicates that venous hypertension may be a risk factor for the development of arteriovenous fistulas. Hybrid techniques are effective in treatment of multifocal and complex spinal AVMs.

A case of filum terminale arterial venous fistula needed a long arterial access for trans-arterial shunt obliteration

A 78-year-old man was referred to our institution with a predominantly progressive numbness of both legs, and bladder dysfunction with urinary retention. He was diagnosed as the symptomatic arteriovenous fistula of the filum terminale (AVFFT). A trans-arterial embolization (TAE) of the arteriovenous shunt was planned for his symptomatic AVFFT. The long distance between the origin of the radiculo meningeal artery (Th8) and the site of the fistula (S1) resulted in the first TAE having a feeder occlusion. The length of accessible feeder in the first TAE was the longest (about 40 cm) as the past reports of the endovascular therapy. However, complete shunt occlusion was accomplished at a second session two weeks after the initial TAE because a more accessible feeder was developed by the initial feeder occlusion.

Endovascular treatment of spinal arteriovenous malformations

Spinal arteriovenous malformations (AVMs) are a rare but treatable cause of myelopathy and spinal cord hemorrhage. The clinical presentation and ideal treatment of these lesions vary widely, primarily due to differences in anatomic and angioarchitectural features. Six well-defined types of fistula have been defined: (1) intradural dorsal AVM; (2) intramedullary AVM; (3) extradural-intradural AVM; (4) intradural ventral AVF; (5) extradural/epidural AVF; and (6) conus medullaris AVM. Each of these lesions have unique clinical presentations and variable natural histories and endovascular treatment options. The principles of endovascular treatment include: (1) a complete understanding of the angioarchitecture and anatomic features of the lesion, including identification of radiculomedullary arteries; (2) careful spinal angiography; (3) identification of treatment goals prior to the procedure (i.e., complete occlusion versus partial occlusion aimed at altering natural history); (4) selection of proper embolic agent; and (5) careful follow-up in both the immediate postoperative setting and long term.

Comparison of 3 Different Types of Spinal Arteriovenous Shunts below the Conus in Clinical Presentation, Radiologic Findings, and Outcomes

BACKGROUND AND PURPOSE

Spinal arteriovenous shunts below the conus constitute 3 types of lesions, which have previously been mainly described in case reports, given their rarity, and are sometimes misdiagnosed. The purpose of this study was to describe the features of each type and compare these types as to epidemiologic features, clinical and radiologic presentations, treatment, and outcomes in a consecutive series of 48 cases.

MATERIALS AND METHODS

The prospectively collected data bases of 2 referral centers for spinal vascular lesions were retrospectively reviewed. Spinal arteriovenous shunts below the conus were defined as all dural and intradural shunts below the conus medullaris. Clinical features, radiologic findings, treatment results, and clinical outcomes were assessed.

RESULTS

There were filum terminale arteriovenous fistulas in 11 patients (22.9%), radicular arteriovenous shunts in 7 patients (14.6%), and spinal dural arteriovenous fistulas in 30 patients (62.5%). Radicular arteriovenous shunts presented at a younger age (P = .017) and with a higher incidence of back pain symptoms (P = .037). A tethered spinal cord was found in 54.5% of patients with filum terminale arteriovenous fistulas and 23.3% of patients with spinal dural arteriovenous fistulas. After treatment, the angiographic complete obliteration rate was 89.4% and spinal function was improved significantly (P < .001).

CONCLUSIONS

Three groups of spinal arteriovenous shunts below the conus can be differentiated according to clinical and radiologic features. Filum terminale arteriovenous fistulas are frequently associated with dysraphic malformations, which may suggest a particular embryologic origin.

Early description of synchronous double spinal vascular malformations by Łucja Frey in 1928

The Polish neurologist Łucja Frey (1889–1942) is principally remembered for her description of the auriculotemporal nerve (or Frey's) syndrome. She also reported a complex case of spinal cord vascular malformation in 1928, which included one of the earliest accurate anatomopathological depictions of a spinal arteriovenous malformation as well as the first known observation of double synchronous spinal cord vascular malformation.

An abbreviated translation of Frey's report is followed by a discussion of the place occupied by her contribution in the development of our current understanding of spinovascular disorders.

Microsurgical anatomy of the arterial basket of the conus medullaris

OBJECT The arterial basket of the conus medullaris (ABCM) consists of 1 or 2 arteries arising from the anterior spinal artery (ASA) and circumferentially connecting the ASA and the posterior spinal arteries (PSAs). The arterial basket can be involved in arteriovenous fistulas and arteriovenous malformations of the conus. In this article, the authors describe the microsurgical anatomy of the ABCM with emphasis on its morphometric parameters and important role in the intrinsic blood supply of the conus medullaris. METHODS The authors performed microsurgical dissections on 16 formalin-fixed human spinal cords harvested within 24 hours of death. The course, diameter, and branching angles of the arteries comprising the ABCM were then identified and measured. In addition, histological sections were obtained to identify perforating vessels arising from the ABCM. RESULTS The ASA tapers as it nears the conus medullaris (mean preconus diameter 0.7 ± 0.12 mm vs mean conus diameter 0.38 ± 0.08 mm). The ASA forms an anastomotic basket with the posterior spinal artery (PSA) via anastomotic branches. In most of the specimens (n= 13, 81.3%), bilateral arteries formed connections between the ASA and PSA. However, in the remaining specimens (n= 3, 18.7%), a unilateral right-sided anastomotic artery was identified. The mean diameter of the right ABCM branch was 0.49 ± 0.13 mm, and the mean diameter of the left branch was 0.53 ± 0.14 mm. The mean branching angles of the arteries forming the anastomotic basket were 95.9° ± 36.6° and 90° ± 34.3° for the right- and left-sided arteries, respectively. In cases of bilateral arterial anastomoses between the ASA and PSA, the mean distance between the origins of the arteries was 4.5 ± 3.3 mm. Histological analysis revealed numerous perforating vessels supplying tissue of the conus medullaris. CONCLUSIONS The ABCM is a critical anastomotic connection between the ASA and PSA, which play an important role in the intrinsic blood supply of the conus medullaris. The ABCM provides an important compensatory function in the blood supply of the spinal cord. Its involvement in conus medullaris vascular malformations makes it a critical anatomical structure.

Multimodality Treatment of Conus Medullaris Arteriovenous Malformations: 2 Decades of Experience With Combined Endovascular and Microsurgical Treatments

BACKGROUND:

Conus medullaris arteriovenous malformations (AVMs) are rare, challenging spinal vascular lesions that cause progressive debilitating myeloradiculopathy. Only sporadic reports of conus AVMs have been published.

OBJECTIVE:

To better define the presentation, prognosis, and optimal treatment of these lesions, we present the first case series of conus AVMs, reflecting over 2 decades of experience with a multimodality endovascular and surgical approach.

METHODS:

We retrospectively reviewed the charts of 16 patients with a conus AVM evaluated at our institution from 1989 to 2010. For each patient, the following clinical data were collected: age, sex, symptoms, angiographic findings, type of treatment, complications, degree of angiographic obliteration, recurrence at follow-up, and need for re-treatment. Ambulatory status, Frankel Grade, motor function, and bladder/bowel function were assessed before treatment, at discharge, and at last follow-up.

RESULTS:

All 16 patients were treated. Eight (50%) patients underwent embolization followed by microsurgical resection, and 8 (50%) underwent microsurgical resection only. The rate of complete angiographic obliteration was 88%. At last follow-up (mean, 70 months), 43% of patients neurologically improved, 43% were stable, and 14% worsened in comparison with before treatment. During follow-up, 3 recurrences were detected, including the only 2 instances of long-term neurological decline. In the absence of recurrence, all patients ambulatory before treatment remained ambulatory at follow-up, whereas 75% of the initially nonambulatory patients regained the ability to walk.

CONCLUSION:

Although conus AVMs are challenging to treat, excellent long-term outcomes are possible with a multimodality approach. Recurrence is associated with long-term neurological decline and calls for close follow-up.