Spinal Sparganosis Coexisting with Acquired Arteriovenous Fistula of the Filum Terminale

Treatment of filum terminale pial arteriovenous fistulas in the sacral region: A case report and systematic review

Spinal filum terminale pial arteriovenous fistulas (FT PAVFs) are uncommon. Most FT PAVFs are located in the lumbar region; far fewer are located in the sacral region. Due to the rarity of sacral FT PAVFs, the precise surgical dissection and removal of these lesions are challenging. Here, we report an FT PAVF in the sacral region. The patient was a 45-year-old male who suffered from progressive weakness and numbness of the bilateral lower limbs; his symptoms gradually worsened. Digital subtraction angiography (DSA) showed an AVF at the sacral canal at the S3-4 level. Microsurgical treatment with intraoperative DSA was performed, and the FT PAVF was resected. After the operation, the patient gradually recovered. Follow-up magnetic resonance imaging revealed a recession in the dilation of the spinal cord venous plexuses. A literature review was also performed, and a total of 14 FT PAVFs of the sacral region were identified. The patients identified in the literature review had an average age of 58.9 ± 12.9 years, and 92.9% of the patients were male. Spinal cord edema was present in 85.7% of the FT PAVF patients. Regarding treatment, 64.3% of the FT PAVF patients underwent microsurgical resection, 28.6% patients underwent endovascular treatment, and 7.1% patients underwent a hybrid operation; good outcomes were achieved with all three methods. Therefore, FT PAVF of the sacral region is a unique lesion whose angioarchitecture needs to be identified carefully; prompt treatment is necessary, and microsurgery can yield good outcomes.

Arteriovenous malformations of the filum terminale: clinical characteristics, angioarchitecture, and management of a rare spinal vascular pathology

OBJECTIVE

The goal of this study was to describe clinical and neuroradiological features of arteriovenous malformations of the filum terminale (FT AVMs) and to present the authors’ diagnostic and therapeutic management in this rare disease.

METHODS

The presented cases were retrieved from a retrospectively collected database of all spinal vascular malformations treated between June 1992 and December 2021 at the Rheinisch-Westfälische Technische Hochschule (RWTH) University Hospital Aachen. Pretreatment and follow-up clinical and neuroradiological data were analyzed for this study.

RESULTS

Data in 15 patients with FT AVM with a mean age of 60 years were included, with an overall incidence of FT AVM of 19% among all spinal AVMs in our cohort. Twelve of 15 (80%) patients were men. Nonspecific but typical clinical and MR findings of thoracolumbar congestive myelopathy were found in all patients. Spinal MR angiography, performed in 10 patients, identified in all cases the arterialized FT vein as well as a lumbar/lumbosacral location of an AV shunt. Digital subtraction angiography (DSA) showed an arterial supply solely via the FT artery in 12/15 (80%) patients and via an additional feeder from the lumbosacral region in the other 3/15 (20%) patients. All patients were treated surgically. During 1-year follow-up, 2 patients presented with recurrent FT AVM due to further arterial supply from the lumbosacral region, and were treated surgically. Neurological status was improved in all patients within the 1-year follow-up, with marginal further changes during long-term follow-up.

CONCLUSIONS

Congestive myelopathy is the major pathological mechanism of symptoms in these patients, with no evidence for intradural bleeding. Missing the presence of possible multiple arterial supply of FT AVM during DSA may result in misdiagnosis and/or insufficient treatment. Due to the frequently prolonged course of FT artery, resection of the FT AVM may be a favorable treatment modality in comparison with endovascular treatment. Follow-up examinations are obligatory within the first 3 years after treatment, and further MR angiography and DSA examinations are indicated if congestive myelopathy persists.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Filum Terminale Arteriovenous Fistula Coexisting with a Large L2-L3 Disc Sequestration and Associated Diffuse Lumbar Arachnoiditis

The authors describe a case of filum terminale arteriovenous fistula (FTAVF) in association with a large L2–L3 disc sequestration and diffuse lumbar arachnoiditis. A 64-year-old male manifested with chronic back pain and gait difficulty. Magnetic resonance imaging (MRI) of the thoracic and lumbosacral spine revealed spinal cord congestion extending from the conus medullaris to the level of T9. There was a large disc sequestration came from L2–L3 disc herniation. In addition, thickening, clumping, and enhancement of the entire cauda equina were noted, probably representing arachnoiditis. MR angiography (MRA) and spinal angiography confirmed FTAVF at the level of L5. The patient underwent laminectomy with lysis adhesions and obliteration of the fistula. His postoperative course was uneventful. MRI and MRA of the thoracolumbar spine obtained 4 months after surgery revealed complete obliteration of the fistula and significant resolution of spinal cord congestion. Enhancement of the cauda equina roots was no longer visible. Interestingly, the significant resorption of the sequestrated disc was documented on MRI. The formation of the FTAVF in the present study may result from severe spinal canal stenosis caused by a large disc sequestration blocking the rostral venous drainage of the fistula, or chronic inflammation, and adhesions of the caudal nerve roots from lumbar arachnoiditis. It seems that FTAVF may be of acquired origin by this evidence.

Acquired Lumbosacral Spinal Dural Arteriovenous Fistula in Association with Degenerative Lumbosacral Disc Herniation and Spinal Canal Stenosis: Report of Two Cases and Review of the Literature

The authors describe two cases harboring lumbosacral spinal dural arteriovenous fistulas (SDAVFs) manifested with nonspecific initial symptoms, leading to misdiagnosis and unnecessary procedures. A curvilinear flow void in the lumbar region and thoracic cord congestion with subtle perimedullary flow voids were detected on magnetic resonance imaging (MRI) in both patients. Contrast-enhanced magnetic resonance angiography and spinal angiography confirmed the SDAVFs in the lower lumbar and sacral region. Both fistulas were located at the same level of disc herniation and spinal canal stenosis and supplied by branches of the internal iliac arteries (i.e., iliolumbar and lateral sacral arteries) with cranial drainage from the dilated vein of the filum terminale, corresponding to a curvilinear flow void, to the perimedullary veins. The first case was successfully treated with embolization. Another case had recanalization of the fistula 4 months after endovascular treatment and was successfully treated with surgical interruption of the fistula. Our two case reports may provide additional evidence supporting an acquired etiology of SDAVFs, probably secondary to lumbosacral disc herniation and spinal canal stenosis. The authors also reviewed literature about preexistent lumbosacral SDAVFs associated with disc herniation and spinal canal stenosis. From our review, the level of SDAVFs in most patients is correlated with the level of disc herniation, spondylolisthesis, and/or spinal stenosis.

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.