Vertebral venous system abnormalities identified with magnetic resonance imaging in sighthounds

Abstract

In humans, abnormalities of the vertebral venous system are considered rare but significant causes of radiculopathy and myelopathy. Published information on abnormalities of the canine vertebral venous system is currently lacking. Aims of this retrospective descriptive study were to characterize magnetic resonance imaging (MRI) abnormalities of the vertebral venous system in a population of sighthounds, report prevalence of vertebral venous system abnormalities within that population and explore possible clinical significance. Our hospital database was searched over the period of 2002-2013 for sighthounds with MRI studies of the vertebral column. Medical records and MRI studies for included dogs were retrieved and findings were recorded by a single observer. A total of 92 sighthounds were sampled. Eleven cases (prevalence 12%) showed abnormal enlargement of the internal vertebral venous plexus (10/11 unilaterally, 1/11 bilaterally), external vertebral venous plexus (7/11 cases unilaterally), and/or intervertebral veins (8/11 unilaterally, 2/11 bilaterally, and 1/11 unilaterally and bilaterally at different sites). The majority of the abnormalities were right sided and the most common location for abnormalities was C6/7. Of the 11 cases, nine did not have a definitive diagnosis. Seven of those nine cases had an abnormality in a neuroanatomical localization that could wholly or partly explain the clinical signs. Findings indicated that, while the prevalence of vertebral venous system abnormalities was low in this sample of sighthounds, the majority of dogs with these abnormalities had clinical signs that matched the location of the abnormalities. Further prospective research is needed to investigate potential underlying aetiologies for vertebral venous system abnormalities in dogs and clarify their clinical significance.

Outcomes and prognostic indicators in 59 paraplegic medium to large breed dogs with extensive epidural hemorrhage secondary to thoracolumbar disc extrusion

“…The ventral internal venous plexus is a bilateral thin‐walled and valveless blood vessel which lies on the floor of the vertebral canal and extends from the basilar sinus of the calvarium to the caudal vertebrae 21 . The vertebral venous system has long been implicated as a route for spread of metastasis or migration of bacterial emboli 22 and, more recently, has been shown to have abnormalities that can cause radiculopathy and myelopathy in dogs 23 . As we confirmed in our study, laceration of this venous plexus due to IVDE can be associated with extensive spinal cord compression, paralysis, and loss of pain perception.…”

“…21 The vertebral venous system has long been implicated as a route for spread of metastasis or migration of bacterial emboli 22 and, more recently, has been shown to have abnormalities that can cause radiculopathy and myelopathy in dogs. 23 As we confirmed in our study, laceration of this venous plexus due to IVDE can be associated with extensive spinal cord compression, paralysis, and loss of pain perception. Our search terms included both IVDE (typically indicating extrusion of calcified nuclear material) and intervertebral disc herniation, which is a broader umbrella term.…”

Morphometrical Study of the Lumbar Segment of the Internal Vertebral Venous Plexus in Dogs: A Contrast CT-Based Study

“…The diagnosis of IVVP engorgement is often mistaken for a herniated disc on radiologic interpretation, and the true diagnosis is finally made in the surgical intervention. In dogs, vertebral venous system abnormalities have been identified on MRI in 12% of all sighthounds, but the underlying cause is unknown [ 14 ]. Recently, severe dilation of the right IVVP causing significant compression of the spinal cord and nerve roots was identified in an adult Scottish Deerhound [ 13 ].…”

“…Recently, venous aneurism of the IVVP in a Scottish Deerhound was reported concurrently with severe dilatation of the venous sinuses [ 13 ]. Additionally, case reports in dogs have described abnormal enlargement of the IVVP in sighthounds by magnetic resonance imaging (MRI) with clinical signs of radiculopathies and myelopathy [ 14 ].…”

MRI characteristics of ventral vertebral venous plexus occlusion due to lymphoma in a large breed dog

“…Lymphoma should be added to other differentials of enlargement of the VVVP that are rare but include congenital malformations and benign neoplasms (sometimes referred to as hamartomas), thrombus, and normal variations (e.g., in Sighthounds). [9][10][11] LIST OF AUTHOR CONTRIBUTIONS…”