Postangiographic thrombosis of a spinal arteriovenous malformation

Spontaneous thrombosis of high flow pediatric arteriovenous fistulae: Case series of two patients and a comprehensive literature review

Pediatric pial arteriovenous shunts in the brain and spine are challenging to understand because of low incidence, variable presentation, and associations with genetic syndromes. What is known about their natural history comes from reviews of small series. To better understand the natural history and role for intervention, two cases are presented followed by a review of the literature. In the first case, an infant with a prior history of intracranial hemorrhage from a ruptured pial fistula returns for elective embolization for a second pial fistula which was found to be spontaneously thrombosed 2 weeks later. In the second case, a 5-year-old with a vertebro-vertebral fistula, identified on work up for a heart murmur and documented with diagnostic angiography, is brought for elective embolization 6 weeks later where spontaneous thrombosis is identified. In reviewing the literature on pediatric single-hole fistulae of the brain and spine, the authors offer some morphologic considerations for identifying which high-flow fistulae may undergo spontaneous thrombosis to decrease the potentially unnecessary risk associated with interventions in small children.

Spontaneous obliteration of a spinal perimedullary fistula

We herewith report a young patient who had an incidental spinal vascular malformation of the cervicomedullary junction discovered during a work-up for anosmia. Angiography demonstrated a perimedullary spinal arteriovenous fistula with supply from lateral spinal arteries arising from bilateral V3 level segmental arteries. It was decided to manage the patient conservatively with magnetic resonance imaging monitored biannually. On a recent follow-up magnetic resonance, nearly 10 years later, we noted a subtle change in caliber and imaging characteristics at the posterior margin of the cervical medullary junction. Repeat digital-subtraction angiography showed no evidence of early venous filling from the previously involved branches. Microcatheter exploration of the right lateral spinal artery confirmed spontaneous occlusion of the spinal perimedullary arteriovenous fistula, without any persistent shunting. Spontaneous resolution of a spinal vascular malformation is rare; this case demonstrates the dynamic nature of shunting vascular malformations and that spontaneous obliteration of arteriovenous shunts is possible.

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.

Parietal Arteriovenous Malformation Mimicking Carotid-cavernous Fistula in Context of Sinus Thrombosis: Bidirectional or Unidirectional Relationship? Literature Review

Cortically located arteriovenous malformations (AVMs) constitute majority of brain AVMs. A common drainage is through respective cortical veins into superior sagittal or transverse sinuses. Through a case report and literature review, we discuss three issues: first, the anomalous drainage of a cortical AVM into an anterior orbital venous drainage system; second, the impact of this drainage on the clinical picture; and third, importantly, the bidirectional versus unidirectional relationship of AVM and old venous sinus thrombosis.

Spontaneous resolution of a thoracic spinal epidural arteriovenous fistula caused by stabbing injury

STUDY DESIGN

A single case is presented of a spontaneously resolving epidural arteriovenous fistula caused by a stab wound.

OBJECTIVE

To demonstrate a unique case of a spontaneously resolving epidural arteriovenous fistula caused by a stab wound, as well as to present a brief review of pathology.

SUMMARY OF BACKGROUND DATA

Spinal epidural arteriovenous fistulas (SEAVF) are high-flow vascular malformations characterized by an arteriovenous shunt involving the internal vertebral venous plexus (IVVP). SEAVFs can present with intramedullary, subarachnoid or epidural hemorrhages, spinal cord or nerve root compression, and progressive myelopathy secondary to medullary venous hypertension. The type of venous drainage (intradural, extradural, or mixed) strongly influences the mode of presentation. Spontaneous resolution of a spinal vascular malformation is a well-documented yet rare phenomenon.

METHODS

Angiographical and magnetic resonance images of the lesion were obtained pre- and post spontaneous resolution. A brief review of the topic is also presented.

RESULTS

Our observation identifies stabbing as an unusual mechanism for the formation of a SEAVF, and offers an angiographically documented example of complete spontaneous resolution of this type of vascular malformation. SEAVFs of traumatic origin have been previously reported, but we believe that our observation represents the first documentation of such a lesion being caused by stabbing with subsequent spontaneous resolution.

CONCLUSION

Spinal epidural arteriovenous fistulas (SEAVFs) are increasingly diagnosed vascular malformations with the potential to inflict serious neurological damage if not recognized and treated in time. Spontaneous resolution of a spinal vascular malformation is a well-documented yet rare phenomenon. Our observation identifies stabbing as an unusual mechanism for the formation of a SEAVF, and offers an example of complete spontaneous resolution of this type of vascular malformation.

Contrast agent induced obliteration of a spinal arteriovenous malformation

We present a patient undergoing spinal angiography and suspected of having an AVM. During the first injection of nonionic contrast, a nidal AVM supplied by the great anterior radiculomedullary artery at T9 left was found. The second injection at T9 left no longer showed the contrast filling of the AVM. Follow-up angiography showed persistent AVM obliteration with an intact arterial spinal axis. The patient's symptoms resolved. Interaction between nonionic contrast, blood, and vessel wall most likely induced the obliteration.

Spontaneous occlusion of a spinal arteriovenous malformation: is treatment always necessary?

Knowledge of spinal cord arteriovenous malformations (AVMs) has recently been improved by studies on pathophysiology, neuroimaging, and genetic data. Nevertheless, the natural history of these lesions remains poorly understood.

The authors present the case of an angiographic regression of a nidal-type spinal AVM at T-12 to L-1 in a 46-year-old woman with no risk factors. The natural course of untreated lesions is reviewed and discussed. To the best of the authors' knowledge, this is the first study that reports an angiographically proven complete spontaneous occlusion of a spinal AVM.