DORSAL SPINAL VENOUS OCCLUSION IN THE RAT

Occlusion of the major components of the spinal venous system is usual ly associated with spinal arteriovenous malformations or systemic thro mbophlebitis, Although spinal venous system dysfunction has been impli cated in compressive cord syndromes, myelopathies from decompression s ickness, and spinal cord trauma, its pathophysiology remains unclear, To characterize disorders associated with spinal venous occlusion, we developed a model in the rat produced by focally coagulating the dorsa l spinal vein transdurally at the T7 and T10 vertebral levels, Followi ng such occlusion, venous stasis, sludging and perivascular hemorrhage s in the small venous branches were observed, By 1 week postocclusion, animals developed hindlimb paralysis from which they partially recove red over time, Histologic examination in the acute phase disclosed tis sue necrosis, edema, and hemorrhages predominantly in the dorsal aspec t of the spinal cord, This was gradually replaced by an intense macrop hagic infiltration and the partial formation of a cystic cavity by 1 m onth, These findings indicate that dorsal spinal vein occlusion in the rat causes significant neurologic and pathologic alterations, We conc lude that this procedure produces a relevant animal model for the stud y of the pathophysiology of spinal venous occlusion, and it allows the characterization of its effects on spinal cord blood flow, the blood- spinal cord barrier, and the development of edema independent of cord compression, Our findings in this model provide an insight into one of the mechanisms of injury extension in spinal cord trauma and other di sorders associated with spinal venous dysfunction.