Diagnosis of spinal dural arteriovenous fistula with multidetector row computed tomography: a case report

Spinal dural arteriovenous fistula presenting as low back pain

Introduction:

Low back pain or numbness of the lower extremities is quite common in the present population. Numerous conditions may cause these symptoms, including spinal vascular anomaly. Identifying and diagnosing the cause of these symptoms are crucial for treatment. Accurate diagnosis based on particular radiological findings in magnetic resonance imaging is crucial for administering adequate therapy to patients, especially in spinal dural arteriovenous fistula.

Case presentation:

We report a case presenting with low back pain and rapid deterioration in paraplegia. Magnetic resonance imaging provided the typical image presentations such as spinal cord edema with tortuous dilated perimedullary venous plexus. The patient was subsequently successfully treated with endovascular embolization.

Discussion:

Spinal dural arteriovenous fistula should be suspected in any patient who presents with myelopathy. Angiography remains the gold standard for confirmation of diagnosis.

Conclusion:

Prompt treatment with endovascular embolization or surgery could improve patients’ outcomes.

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

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

Clinical application and diagnostic value of noninvasive spinal angiography in spinal vascular malformations

OBJECTIVE

The purpose of this study was to explore the value of computed tomographic (CT) spinal angiography with 256-slice CT and fast dynamic contrast-enhanced 3-dimensional magnetic resonance angiography (MRA) at 3.0 T in the diagnosis of spinal vascular malformations.

METHODS

Seventeen patients who presented with suspected spinal vascular diseases by initial magnetic resonance and clinical findings all underwent CT spinal angiography. Among these, 10 patients underwent MRA, 15 patients underwent digital subtraction angiography (DSA) within 3 to 5 days, and 8 patients finally underwent surgical treatment.

RESULTS

Computed tomographic angiography examination clearly showed the abnormal vascular lesions in 16 of the 17 patients, including 7 patients with the diagnosis of spinal dural arteriovenous fistula, 7 patients with perimedullary arteriovenous fistula, and 2 patients with spinal arteriovenous malformations. The results were consistent with the diagnosis of DSA or surgery. One patient was poorly diagnosed. The fistulas could be seen in 12 patients; feeding arteries were correctly displayed in 12 patients. The fistulas and feeding arteries were accurately shown in 7 of 10 patients by MRA; DSA results were also negative in the other 3 patients.

CONCLUSIONS

Spinal angiography with 256-slice CT and contrast-enhanced MRA at 3.0 T can clearly show the extent of spinal vascular malformations, feeding arteries, and fistulas. They are safe, noninvasive, as well as rapid and can shorten the time of DSA diagnosis and treatment.

[Computed tomography (CT) angiography with multidetector row helical CT for detecting spinal dural arteriovenous fistula]

A 59-year-old man had have dysuria and left thigh pain for 2 months. He also experienced transient weakness of both legs twice, which recovered within a few hours. One month ago, he had bowel disturbance. Lumbar MRI showed a swelling of the conus medullaris. Enlarged and tortuous vessels behind the spinal cord on lumbar MRA and CT myelography was demonstrated. Though angiogram through intercostal and lumbar arteries revealed no abnormal findings, CT angiography with multidetector row helical CT (MDCT) showed abnormal vessel in intradural space at sacral level. Angiogram through left internal iliac artery revealed abnormal vessel fed by branches of the lateral sacral artery at the early arterial phase. Thus, diagnosis of dural arteriovenous fistula (DAVF) at the left S1 level was confirmed. It was indicated that CT angiography with MDCT was useful in detecting spinal DAVF especially at sacral level.

Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.

The role of non-invasive computed tomography in patients with suspected dural fistulas with spinal drainage

OBJECTIVE

Accurate diagnosis and demonstration of the angioarchitecture and localization of a spinal dural arteriovenous fistula is of crucial importance before treatment. Selective spinal angiography (DSA) has been considered the standard technique, but is invasive, time-consuming, and may be falsely negative. This report evaluates the use of noninvasive vascular imaging (computed tomographic and magnetic resonance angiography [MRA]) in patients suspected to have a dural fistula with spinal drainage.

METHOD

Ten consecutive patients had DSA and multidetector computed tomographic angiography (MDCTA), eight also had MRA. Nine were men with an average age of 67 years. In nine patients, the diagnosis was confirmed at surgery or intravascular treatment. Eight were proven to have a spinal dural fistula. In two, the fistula was within the cervical cranial dura. In all patients, the venous drainage involved only the spinal venous plexus.

RESULTS

MDCTA identified the level of the feeding artery in nine patients. In two cases, selective DSA failed to show the abnormality found on MDCTA, but both were confirmed at surgery. MRA was diagnostic in a case in which the lesion was not accurately depicted by either MDCTA or DSA. MRA was less accurate than MDCTA in determining the level of the feeding artery.

CONCLUSION

MDCTA and MRA can direct and focus DSA. MDCTA gives additional useful three-dimensional bone detail and localization information for the surgeon. It may replace DSA if surgery is the planned treatment.

Spinal dural arteriovenous fistula

PURPOSE OF REVIEW

To summarize clinical key points, diagnostic features, and results of imaging and therapy of spinal dural arteriovenous fistula (SDAVF).

RECENT FINDINGS

SDAVF accounts for 70% of spinal arteriovenous malformation with an annual incidence of 5-10 cases per million. At least 80% of patients are male, and more than 66% of patients are in the sixth and seventh decade of life indicating preponderance of gender and age. Thrombophilia is not a predisposing factor of disease. Clinical course is predominated by symptoms of congestive myelopathy, but subarachnoid hemorrhage may occur. Double SDAVF is a rare problem in the management of disease. Magnetic resonance imaging has replaced myelography as screening procedure. Contrast-enhanced magnetic resonance angiography and multislice computerized tomographic angiography may facilitate diagnostic procedure, however, spinal angiography is still required to confirm diagnosis. Treatment by permanent occlusion of fistula results in clinical improvement in 70% of cases. Microsurgical shunt interruption has proven secure and reliable. Endovascular shunt embolization has been established as a standardized procedure, but occlusion rates are still lower than in surgical treatment.

SUMMARY

Advances have been made in diagnosis and treatment of SDAVF, but the disease is still not completely understood.