Tierärztliche Hochschule Hannover Vergleichende Studie zur

Publikation 3
lumbar vertebral body, a punctual lesion of less than 1 mm in diameter designated
the puncture site. A small arterial thrombus was firmly attached to the inner surface of
the contralateral vessel wall on an area of approximately 5 mm in diameter and
protruded 1-2 mm into the lumen. Microscopic examination of the arterial thrombus
displayed ongoing organization characterized by infiltrating macrophages
occasionally containing intracytoplasmic brown granular pigment (hemosiderin),
capillary sprouts and fibroblasts. Gross examination of the spinal cord revealed a
locally extensive bilateral malacia and focal hemorrhage of the grey matter extending
from the 4 th lumbar spinal nerve root to the caudal end of the sacral spinal cord
(Figure 2). Microscopically, sections of the affected spinal cord segment contained
extensive bilateral malacia of the grey matter and the adjacent central parts of the
white matter (Figure 3), characterized by necrotic neurons and glial cells,
disintegration of neuropil, myelin sheaths and axons, as well as a peripheral zone of
intercellular edema, multifocal perivascular hemorrhages and infiltrating
macrophages and fewer lymphocytes. Many macrophages / microglia displayed an
enlarged size and foamy cytoplasmic change (“gitter cells”) indicative of phagocytotic
activity. The arteria (A.) spinalis ventralis, and multiple other small to medium sized
arterial vessels (Aa. sulcocomissurales, Aa. radicularis dorsalis; multiple rami
marginales within the white matter) ranging from the area of the 4 th lumbar spinal
nerve root to the caudal end of the sacral cord displayed a multifocal partial to total
occlusion of the vessel lumina by fibrin-rich thrombi, displaying multifocal attachment
to the vessel walls with endothelial necrosis and loss, whereas they exhibited no
contact to the vessel walls in other areas. These thrombi displayed signs of
organization characterized by surface re-endothelization, hyaline change of the fibrin,
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