Epidural Hematoma Caused by a Spinal Osseous Epidural Arteriovenous Fistula in a 14-Year-Old Patient

Spinal dural arteriovenous fistulae are the most common type of spinal vascular malformations (AVMs). They have been classified into four types: dural AVM (type I), glomus AVM (type II), juvenile AVM (type III), and intradural direct arteriovenous fistula (type IV). Intradural AVMs manifest as subarachnoid or intramedullary hemorrhages, whereas dural AVM manifest as epidural hematoma. Spinal osseous epidural arteriovenous fistula (AVF) is not a well-defined vascular abnormality in the spine and consists in a high-flow vascular lesion outside the dura or spinal canal. It is located in the extradural space involving a bone at the area of the dilated venous sac to which all the feeders converge to the margin. We describe the case of a 14-year-old girl with cervical epidural hematoma caused by a spinal epidural arteriovenous fistula.

Paraplegia after Tethered Cord Surgery: An Uncommon Combined Anomaly of Spinal Arteriovenous Fistula and Sacral Lipoma— Case Report

ABSTRACT OBJECTIVE AND IMPORTANCE: The coexistence of spinal arteriovenous malformation (AVM) with congenital abnormalities is relatively common. However, the association of a spinal AVM and lipoma is rare. We present an adult patient with this combined anomaly and discuss the clinical relevance of this case. CLINICAL PRESENTATION: A 42-year-old Caucasian man with progressive paraparesis initially underwent surgery for a tethered spinal cord. Postoperatively, he became paraplegic. He improved gradually over an interval of 8 months and, at that point, worsened again. Subsequent angiographic study revealed a spinal dural arteriovenous fistula located at S1–S2. Additionally, an occipital dural AVM was discovered near the transverse sinus. INTERVENTION: The spinal arteriovenous fistula was excised along with the sacral lipoma. The occipital arteriovenous fistula was embolized successfully at a later time. CONCLUSION: The patient had immediate improvement in sensory symptoms after surgery. At a 9 month follow-up examination, he had regained the ability to walk with crutches, but his bladder dysfunction persisted. Recognition of co-existing vascular anomalies, such as spinal AVMs, is important in patients with tethered cords. The mechanisms involved in this patient's worsening neurological condition after release of the tethered cord are discussed.

Paravertebral Arteriovenous Malformation Supplied by Branches of the Iliac Arteries

Arteriovenous malformations of the spine and spinal cord can be classified into spinal cord arteriovenous malformations (AVMs) and fistulas (AVFs) and dural AVM and AVF occurring outside the dura but draining into the epidural veins called paravertebral AVM and AVF 1. Paravertebral malformations are rare arteriovenous communications outside the dura but draining into the epidural veins. These malformations produce symptoms from either venous congestion of the cord or cord compression from dilated epidural veins resulting in a myelopathy. We present a case of a patient with a lumbar paravertebral malformation treated successfully by endovascular occlusion of the feeders.

Combined transvenous and transarterial embolization of a tentorial—incisural dural arteriovenous malformation followed by primary stent placement in the associated stenotic straight sinus

✓ Dural arteriovenous malformations (AVMs) involving the tentoria—incisura are associated with an aggressive clinical course characterized by subarachnoid and intracranial hemorrhage (ICH). In these lesions, venous outflow obstruction precipitates leptomeningeal venous drainage, resulting in the arterialization of pial veins and the formation of venous aneurysms, both of which are prone to hemorrhage. Stenotic lesions of the dural sinuses also contribute to the development of retrograde leptomeningeal drainage, which is responsible for the aggressive clinical course of the dural AVM. Endovascular approaches are successful in the treatment of these lesions and of any potential venous outflow obstruction caused by stenosis of a dural sinus. The authors report on a patient with a tentorial—incisural dural AVM and an accompanying stenotic venous sinus. A combined transvenous and transarterial embolization procedure was performed, resulting in complete obliteration of the dural AVM, followed by primary stent placement across a stenotic segment of the straight sinus and normalization of venous outflow. The authors conclude that dural AVMs can be treated safely by using a combined transarterial and transvenous approach and that an extensive search for venous outflow obstruction often reveals stenosis of a draining sinus. Consideration should be given to primary stent placement in the stenotic sinus to protect against ICH.

Arteriovenous fistula with associated aneurysms coexisting with dural arteriovenous malformation of the anterior inferior falx

✓ This 24-year-old man presented with an unusual case of a high-flow arteriovenous fistula (AVF). This lesion was similar to giant AVFs in children that have been previously described in the literature. In patients in whom abnormalities of the vein of Galen have been excluded and in whom presentation occurs after 20 years of age, a diagnosis of congenital AVF is quite unusual.The fistula in this case originated in an enlarged callosomarginal artery and drained into the superior sagittal sinus via a saccular vascular abnormality. Two giant aneurysmal dilations of the fistula were present. In an associated finding, a small falcine dural arteriovenous malformation (AVM) was also present. Arterial supply to the AVM arose from both external carotid arteries and the left vertebral artery, with drainage through an aberrant vein in the region of the inferior sagittal sinus into the vein of Galen.Craniotomy with exposure and trapping of the AVF was performed, with subsequent radiosurgical (linear accelerator) treatment of the dural AVM. Through this combination of microsurgical trapping of the AVF and radiotherapy of the dural AVM, an excellent clinical outcome was achieved.

Usefulness of MRA in the Treatment of Dural AVM

We report 5 cases of dural AVMs, in which MRA images were considered very useful for evaluating the effectiveness of treatments, such as transvenous embolization therapy. MRA by time of flight method (TOF) with contrast medium for dural AVMs involving the cavernous sinus (dural CCFs) is necessary to assess the caliber of superior ophthalmic veins (SOVs) prior to treatment as well as immediately after treatment and during follow-up. MRA for dural AVM at the transverse-sigmoid sinus is useful for verifying thrombosed sinus in the dural AVM prior to transvenous embolization therapy and necessary to determine the approach to the nidus of the dural AVM2.

Redefined role of angiogenesis in the pathogenesis of dural arteriovenous malformations

✓ To investigate the role of angiogenesis in the pathogenesis of dural arteriovenous malformations (AVMs), 40 rats underwent common carotid artery—external jugular vein (CCA-EJV) anastomosis, bipolar coagulation of the vein draining the transverse sinus, and sagittal sinus thrombosis to induce venous hypertension. Fifteen rats underwent a similar surgical procedure, but venous hypertension was not induced. The 55 rats were divided into seven groups. Four groups, each containing 10 rats, underwent induced venous hypertension. The other three groups, each containing five rats, did not undergo induced venous hypertension. After 1, 2, or 3 weeks, dura mater was obtained from one group of hypertensive rats and from one group of nonhypertensive rats and was assayed for angiogenic activity (rabbit cornea bioassay). The remaining group of 10 hypertensive rats was not assayed to determine if sampling affected dural AVM formation. Unlike rats without CCA-EJV anastomosis, rats with CCA-EJV anastomosis had significantly increased postoperative sagittal sinus pressures (p < 0.0001). Mean angiogenesis indices were significantly greater in rats with venous hypertension than in rats without venous hypertension (p = 0.004). Dural AVMs formed in 42% of the 55 rats and facial AVMs formed in 51%. Angiogenic activity correlated positively with venous hypertension (ρ = 0.74). Development of dural AVMs correlated positively with both venous hypertension (p = 0.0009) and angiogenic activity (p = 0.04). These data indicate that venous hypertension may induce angiogenic activity either directly or indirectly by decreasing cerebral perfusion and increasing ischemia, and that dural AVM formation may be the result of aberrant angiogenesis.