Epidural anatomy examined by cryomicrotome section. Influence of age, vertebral level, and disease.

BACKGROUND AND OBJECTIVES: Cryomicrotome section is a means of anatomic examination with minimal artifact ideally suited to delineating details of tissue relationships in the epidural space. In the past, healthy adult lumbar levels have been studied by this method. This report extends observations to other regions of the vertebral column, other age groups, and some abnormal conditions.
METHODS: The bodies of 26 adults were frozen in toto soon after death, and the bodies of 2 children were frozen after embalming. Unstained anatomy was revealed by sectioning, and the exposed surface was photographed.
RESULTS: As compared with the lumbar level, there are diminished epidural contents at the thoracic and cervical levels, and the ligamentum flavum is more frequently discontinuous. A large basivertebral vein with its origin in the anterior epidural space is typical of the lower thoracic and upper lumbar levels. Although the epidural contents are typically divided into compartments, there is incomplete segmentation of the posterior compartments during early childhood and often at thoracic levels in adults. In advanced age with degenerative disc and joint changes, distortion and compression of the epidural space are typical.
CONCLUSIONS: Variations in epidural anatomy due to vertebral level, age, and disease may alter the ease of epidural entry and passage of catheters and injected solution.