Embolization of Sacral Dural Arteriovenous Fistulas: A Case Series and Literature Review

Neurologic pathologies of the vertebral spine

At some institutions, musculoskeletal and general radiologists rather than neuroradiologists are responsible for reading magnetic resonance imaging (MRI) of the spine. However, neurological findings, especially intrathecal ones, can be challenging. Intrathecal neurological findings in the spine can be classified by location (epidural, intradural extramedullary, and intramedullary) or etiology (tumor, infection, inflammatory, congenital). In this paper, we provide a succinct review of the intrathecal neurological findings that can be seen on MRI of the spine, primarily by location and secondarily by etiology, in order that this may serve as a helpful guide for musculoskeletal and general radiologists when encountering intrathecal neurological pathologies.

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 supplied by bilateral lateral sacral arteries: case report and literature review

Sacral dural arteriovenous fistulas (DAVFs) with bilateral arterial supplies are extremely rare. To date, only two cases with arterial supply from bilateral lateral sacral arteries (LSAs) were reported. We report a rare case of sacral DAVF with arterial supply from bilateral LSAs. A 56-year-old man presented with a 2-month history of progressive weakness and numbness in his lower extremities, along with urinary incontinence. Spinal magnetic resonance imaging (MRI) showed extensive edema of the spinal cord, vascular flow voids, and intraparenchymal enhancement. Spinal angiography revealed a spinal DAVF at the level of S1 supplied by bilateral LSAs and drained ascending into the perimedullary venous plexus. The fistula was successfully treated with endovascular embolization. Sacral DAVFs present various diagnostic and treatment difficulties because of the complex angioarchitecture. Successful management of these lesions requires a profound understanding of the variable patterns of arterial supply in this region.

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.

Clinical and radiographic characteristics of sacral arteriovenous fistulas: a multicenter experience

OBJECTIVE

Available data on management of sacral arteriovenous fistulas (sAVFs) are limited to individual case reports and small series. Management includes observation, endovascular embolization, or surgical ligation, with no clear guidelines on the optimal treatment modality. The authors' objective was to report their multiinstitutional experience with management of sAVF patients, including clinical and radiographic characteristics and postprocedural outcomes.

METHODS

The electronic medical records of patients with a diagnosis of spinal arteriovenous fistula treated from January 2004 to December 2019 at the authors' institutions were reviewed, and data were summarized using descriptive statistics, including percentage and count for categorical data, median as a measure of central tendency for continuous variables, and interquartile range (IQR) as a measure of dispersion.

RESULTS

A total of 26 patients with sAVFs were included. The median (IQR) age was 65 (57-73) years, and 73% (n = 19) of patients were male. Lower-extremity weakness was the most common presenting symptom (n = 24 [92%]), and half the patients (n = 13 [50%]) reported bowel and bladder sphincter dysfunction. The median (IQR) time from symptom onset to treatment was 12 (5.25-26.25) months. Radiographically, all patients had T2 hyperintensity at the level of the conus medullaris (CM) (n = 26 [100%]). Intradural flow voids were identified in 85% (n = 22) of patients. The majority of the lesions had a single identifiable arterial feeder (n = 19 [73%]). The fistula was located most commonly at the S1 level (n = 13 [50%]). The site where the draining vein connects to the pial venous plexus was seen predominantly at the lumbar level (n = 16 [62%]). In total, 29 procedures were performed: 10 open surgeries and 19 endovascular embolization procedures. Complete occlusion was achieved in 90% (n = 9) of patients after open surgery and 79% (n = 15) after endovascular embolization. Motor improvement was seen in 68% of patients (n = 15), and bladder and bowel function improved in 9 patients (41%). At last follow-up, 73% (n = 16) of patients had either resolution or improvement of the pretreatment intramedullary T2 signal hyperintensity.

CONCLUSIONS

T2 hyperintensity of the CM and a dilated filum terminale vein are consistent radiographic signs of sAVF, and delayed presentation is common. Complete occlusion was achieved in almost all patients after surgery, and endovascular embolization was effective in 70% of the patients. Further studies are needed to determine the best treatment modality based on case-specific characteristics.

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.

The Shunt Point of the Sacral Dural Arteriovenous Fistula: A Case Report and Literature Review

BACKGROUND

The occurrence of sacral dural arteriovenous fistula (dAVF) is rare. The detailed vascular architecture of sacral dAVF, including 3-dimensional (3D) angiographic images with operative findings, has not been evaluated compared with that of the thoracic and lumbar levels. We report a case of sacral dAVF with 3D angiographic examination and operative findings, with a literature review.

CASE DESCRIPTION

A 60-year-old man presented with progressive urinary incontinence and gait disturbance. A sacral dAVF was detected at the S1-2 level. The shunt point was at the medial side of the line between the intermediate sacral crest and the most medial point of the L5 pedicle circle at the anterior posterior view of the angiography; we defined this type as the medial type. After embolization, latent inflow arteries were visualized ipsilaterally and contralaterally. During surgery, because of dAVF recurrence, a vascular tangle was found on the dura. The surgical interruption of the draining vein improved the patient's symptoms. From the literature review, 92% of cases had medial-type shunt point. It is possible for sacral dAVF to have multiple inflow arteries originating ipsilaterally or bilaterally, and a venous pouch.

CONCLUSIONS

The shunt point of sacral dAVF tended to be located medially, not in the sacral foramen. Sacral dAVF has unique angioarchitecture. The differentiation of dAVF from epidural arteriovenous fistula may not be easy in some cases of sacral lesions. Therefore, further studies with a larger number of patients focused on the detailed vascular architecture are needed.

A Rare and Treatable Cause of Medullar Claudication: Spinal Dural Arteriovenous Fistula

Background: Spinal dural arteriovenous fistula is a rare and underdiagnosed disorder. Because of the nonspecific clinical presentation of the condition, patients are often referred to different specialists, resulting in delayed diagnosis.

Case Report: A 76-year-old male presented with a 1-month history of gait trouble. His impairment was asymmetric, distally predominant, sensitive, and motor. Symptoms worsened with standing and walking. The patient also had sphincterial dysfunction. Classic spinal cord magnetic resonance imaging (MRI) showed an extended hypersignal indicating nonspecific myelopathy. Repeat spinal cord MRI that included a T2 spin echo sequence revealed abnormalities suggesting dural arteriovenous fistula. Medullar angiography confirmed the diagnosis, and endovascular treatment was successfully performed. Six months posttreatment, the patient reported resolution of his neurologic disabilities except for some residual paresthesia in his inferior limbs.

Conclusion: Physicians should be aware of the specific abnormalities shown on spinal cord MRI that indicate dural arteriovenous fistula, as well as the criteria for performing medullar angiography, so that the condition can be diagnosed and treated in a timely manner. Early therapeutic treatment is the principal prognosis factor.

Sacral dural arteriovenous fistulas: a diagnostic and therapeutic challenge – single-centre experience of 13 cases and review of the literature

Background

Sacral dural arteriovenous fistulas (DAVFs) are rare vascular abnormalities of the spine characterised by slowly progressive symptoms that can mimic different myelopathy disorders.

Object

To report our single Institution experience with sacral DAVFs.

Methods

We retrospectively reviewed the clinical records of patients admitted from 1 January 2006 to 31 December 2016 with a diagnosis of sacral DAVFs, treated by endovascular embolisation or surgical clipping. Clinical presentation, imaging characteristics, treatment results and follow-up were analysed.

Results

We identify 13 patients with sacral DAVFs supplied by lateral sacral arteries. Clinical presentation was characterised by different degrees of motor weakness and sphincter disturbances. In all patients, spinal MRI showed spinal cord hyperintensities with enhancement and prominent perimedullary vessels. Selective internal iliac angiography was mandatory to identify the exact location of the fistula. A complete embolisation was achieved in eight patients performing a single endovascular embolisation and in three patients performing a single surgical disconnection: two patients required combined procedures. Follow-up imaging showed a complete resolution of the spinal cord hyperintensities in 81% of patients and a reduction of the intramedullary enhancement in 91%. Gait improvement was observed in 73% of patients, while remaining stable in 27%. Sphincter disturbances improved in 36% of patients and remained stable in 64%.

Conclusion

Awareness of sacral location of DAVFs is critical because standard spinal angiography will not identify sacral supplies, unless internal iliac arteries are properly examined. In our experience, the endovascular treatment show results comparable to surgery when the fistula point is correctly disconnected.