Therapeutic Clues In Spinal Dural Arteriovenous Fistulas – A 30 Year Experience Of 156 Cases

Abstract

Microsurgery can be recommended as the first choice treatment when the fistula's point is unmistakably identified intradurally. Endovascular obliteration may be justifiable in cases with an easy access to a monoradicular feeding artery during diagnostic angiography. Surgery is a definitive treatment with stable long-term results in which procedure-related morbidity is low. During evolution of the combined approach, endovascular coil placement for correct localization of the fistula and the use of intraoperative micro-Doppler was found to be very helpful in increasing the safety of the surgical procedure and minimizing surgical exposure.

Absence of abnormal vessels in the subarachnoid space on conventional magnetic resonance imaging in patients with spinal dural arteriovenous fistulas

“…13,17,20,23 Patients most often present in the 5th or 6th decade of life, with a strong male predominance of approximately 5:1 in reported series. 8,16,17 Although the majority of spinal DAVFs are found in the mid-to lower thoracic spine, 9 venous congestion and subsequent myelopathy often begins in the caudal aspect of the spinal cord irrespective of the actual fistula level.…”

“…17,21 They are slow-flow arteriovenous shunts characterized by an abnormal connection between a radicular artery and vein that is found most often in, or near, the dura of a nerve root sleeve. 8,13,16,17,23 The resulting venous congestion and hypertension, first suggested by , 4 eventually results in a progressive congestive myelopathy from the decrease in the arteriovenous pressure gradient, cord ischemia, and eventually infarction with neuronal loss. 8,13,15,17,21 Hassler and Thron 12 confirmed this hypothesis by demonstrating a venous pressure in a DAVF of approximately 70% of the patient's systemic arterial pressure.…”

“…17,23 Patients consequently most often present with nonspecific symptoms involving changes in sensation and strength in the lower extremities, lowerextremity pain sometimes exacerbated by exercise, and disturbances in gait. 6,8,13,16,29 These symptoms overlap significantly with those of more common diseases such as spinal canal stenosis and polyneuropathy. 9,16,17 As the myelopathy progresses, patient often will experience continued loss of lower-extremity strength leading to paraplegia, as well as develop abnormalities in micturition, defecation, and sexual function.…”

“…9,16,17 As the myelopathy progresses, patient often will experience continued loss of lower-extremity strength leading to paraplegia, as well as develop abnormalities in micturition, defecation, and sexual function. 17 Conventional MRI is frequently the initial diagnostic examination in patients with a spinal DAVF, suspected or otherwise, and this represents a critical decision point for Absence of abnormal vessels in the subarachnoid space on conventional magnetic resonance imaging in patients with spinal dural arteriovenous fistulas 10,13,17,24 The MRI findings of spinal cord T2 prolongation, intramedullary enhancement, and prominent vessels in the subarachnoid space as demonstrated by flow voids on T2-weighted imaging and enhancement on postcontrast T1-weighted imaging are considered characteristic for this disease. 11,14,17,22,24 Although this combination of findings on conventional MRI is thought to be both fairly sensitive and specific for the diagnosis of a spinal vascular malformation, these findings may not all be present in a significant proportion of patients.…”

“…11,14,17,22,24 Although this combination of findings on conventional MRI is thought to be both fairly sensitive and specific for the diagnosis of a spinal vascular malformation, these findings may not all be present in a significant proportion of patients. 11,13,14,22,24 We present a series of 4 cases involving patients with proven spinal DAVF who demonstrated spinal cord edema and enhancement without abnormal flow voids or enhancement in the subarachnoid space on conventional MRI. Three patients presented at our academic referral center, and the fourth presented at another academic practice.…”