Spinal cord vascular shunts: spinal cord vascular malformations and dural arteriovenous fistulas

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Spinal cord vascular malformations are rare, fascinating lesions. In this paper, the authors' goal was to demonstrate how these lesions, more specifically spinal cord arteriovenous malformations and dural arteriovenous fistulas, are assessed, classified, and managed at their institution. They also highlight some aspects of classification and management that may be different from the views of others.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors reviewed the 20-year experience at the senior author's institution regarding the management of spinal cord vascular malformations. They discuss the management, surgical and endovascular treatment results, and the classification that resulted from the combined experience of 3 major reference centers.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>The accumulated knowledge on embryological and pathophysiological aspects in such a rare disease resulted in a more global, patient-oriented (and not radiologically oriented) approach to spinal cord shunts.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The multiple classifications proposed for spinal cord vascular malformations reflect the continuous advancement of the authors' understanding. They adopt a classification based on new physiological and genetic data that treats these lesions as expressions of more complex disease processes and not simply a morphological target, with direct impact on therapeutic options.</jats:p></jats:sec>

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

“…9,17 Successful treatment requires occlusion of the draining, arterialized, intradural vein, which has been found to provide a lasting and durable treatment of the symptoms of spinal DAVFs. 1,8,25 Currently, surgical ligation, endovascular embolization, and a multidisciplinary approach are all used for the treatment of spinal DAVFs. 9,30,32,33 Once the diagnosis of a spinal DAVF has been made and the fistula has been successfully closed, a majority of patients, up to 80%-90% in some series, 17 will demonstrate either improvement or stabilization of symptoms, particularly lower-extremity strength.…”

“…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. 17,23 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.…”

“…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.…”

“…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.…”

Spinal Dural Arteriovenous Fistulas: Clinical and Radiological outcome of Endovascular Treatment

“…37 If the lesion is not treated, 50% of patients will become severely disabled and less than 10% will be able to walk independently after 3 years. 9 Favorable outcome depends on the progression of neurologic deficits at the time of diagnosis, which makes early diagnosis preferable. 15 SDAVFs can be treated by surgery with clip placement or coagulation of the vein from a posterior spinal laminectomy approach.…”