Spinal dural arteriovenous shunt presenting with intramedullary hemorrhage

The authors report on a 49-year-old man with a thoracic spinal dural arteriovenous shunt (dAVS) in which rupture of a varix caused intramedullary hemorrhage. In the literature, patients with a thoracic dAVS predominantly present with congestive myelopathy; however, the patient featured in this report presented without increased deep tendon reflexes or muscle weakness, but instead with intermittent stabbing chest pain and paresthesia. Magnetic resonance images and angiograms demonstrated tortuous enlargement and the formation of a varix-like structure of the draining veins, features compatible with those of high-flow angiopathy. Recognition of this phenomenon is important in thoracic dAVS because intramedullary hemorrhage dramatically degrades outcome. A high index of clinical suspicion can prevent a similar case of thoracic dAVS from progressing to intramedullary hemorrhage.

Dural Arteriovenous Shunt Development in Patients with Vein of Galen Malformation

Dural arteriovenous fistulas (DAVF) associated with our series of patients with vein of Galen malformations (VOGM) are analyzed and discussed. We retrospectively analyzed 87 consecutive cases of VOGM treated between May 2002 and December 2011 and identified 26 patients with DAVF. We gathered information from the clinical case records, angiographic images, MRI on presentation and during follow-up. The findings were analyzed to aid discussion. Among 87 patients treated by multi-stage endovascular embolization, age range from newborn to 19 years, 26 (30%) had DAVF. In seven patients (8%), DAVF were found on initial angiogram and were all into the VOGM. Nineteen (21%) DAVF found on follow-up angiograms were all into the VOGM and distant locations. Sprouting and non-sprouting angiogenesis resulted in the formation of a network of vessels around partially thrombosed VOGM, recruiting blood from the surrounding dura mater resulting in a secondary network on the dura mater supplied by the blood vessels of dura mater in the region or from its natural collaterals. Embolization targeting DAVFs was done in 13 (52%) with complete cure in eight (32%) and recurrence in five (20%). Among 12 non-embolized patients (48%), eight (32%) had spontaneous regression with continued treatment of VOGM. In others, the DAVF either remained stable or progressed. DAVF associated with VOGM represent the dural response to angiogenic stimuli. They are observed to regress spontaneously or mature while continuing to treat the primary feeders of VOGM. It is important to include the external carotid system during angiograms. Persistent DAVF with residual VOGM that do not have access though the pial vessels are used as a conduit to treat the dural shunt and to achieve obliteration of residual VOGM at later stages of treatment.

Cognard Type V Intracranial Dural Arteriovenous Shunt

BACKGROUND AND IMPORTANCE: Prompt diagnosis of intracranial dural arteriovenous shunt (DAVS) with spinal venous drainage, classified as Cognard type V, is difficult. We investigated the angiographic and magnetic resonance imaging (MRI) characteristics of Cognard type V DAVS to determine the reason for the difficulty in early diagnosis. CLINICAL PRESENTATION: We systematically reviewed 54 published and 3 new cases of Cognard type V DAVS. The pattern of venous drainage was classified on the basis of relative dominance of the anterior and posterior spinal veins with the use of angiograms. T2-weighted sagittal MRIs were used to detect signal flow voids of enlarged spinal veins. Types of venous drainage were determined in 49 of the 57 cases. Twenty-eight and 8 cases showed a dominance of anterior and posterior spinal venous drainage, respectively. In 13 cases, venous drainage was equally distributed through the anterior and posterior spinal veins. Of 41 cases with an abnormally dilated anterior spinal vein, MRIs were available for 25 cases. Signal flow voids of enlarged anterior spinal veins were detected in 9 cases (36.0%), whereas dilatation of the posterior spinal veins was apparent in 9 of 16 cases (56.3%). Overall, MRI detected enlargement of either anterior or posterior spinal veins in 15 of 41 cases (36.6%). CONCLUSION: In Cognard type V DAVS, anterior venous drainage is dominant. Because the anterior spinal veins are located subpially, flow voids are less prominent on sagittal T2-weighted MRI. This may lead to difficulties in diagnosing. Evaluation with MR angiography may compensate for these limitations.

Regression of a Flow-Related Ophthalmic Artery Aneurysm after Treatment of a Frontal DAVS

We report a case of a frontal dural arteriovenous shunt or fistula (DAVS) adjacent to the left side of the cribriform plate, with bilateral supply from multiple arteries, the most prominent being the dural branches originating from the anterior ethmoidal artery coming from the left ophthalmic artery. Before treatment there was an eight mm flow-related arterial aneurysm proximally on the left ophthalmic artery. After transarterial embolization of the DAVS with N-butyl cyanoacrylate and polyvinyl alcohol, minimal shunting still remained. At follow-up angiography six months after the treatment, the shunt was obliterated and the ophthalmic artery aneurysm had regressed completely. Our case illustrates that complete obliteration of a DAVS may be achieved even though arteriovenous shunting remains at the end of the procedure. Furthermore, a flow-related arterial aneurysm, may not warrant any specific treatment. Elimination of the high flow situation can lead to complete regression of these aneurysms.

Spontaneous Recanalization of Occluded Dural Venous Sinuses after Successful Trans Arterial Embolisation of a Dural Arteriovenous Shunt

Dural arteriovenous shunts (DAVS) occur within the walls of dural venous sinuses or their tributaries. They may be related to previous episodes of sinus thrombosis. The presence of impediments to venous outflow results in venous congestion, predisposing to haemorrhage and cerebral parenchymal damage. Cerebral venous congestion is an indication for treatment. This case is unusual in some respects; firstly, the patient was relatively well despite worrisome features on imaging and secondly the occluded dural venous sinuses appeared to spontaneously recanalize after treatment of the DAVS. Anticoagulation may have had a role in avoiding thrombosis of the patient's precarious venous drainage after embolisation and in encouraging recanalization of the thrombosed dural venous sinuses.