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Review
. 2022 May;22(5):182-189.
doi: 10.1016/j.bjae.2021.12.006. Epub 2022 Feb 23.

Update on applied epidural anatomy

D Macpherson  1 , F Quondamatteo  2 , M Broom  1
Affiliations
Review

Update on applied epidural anatomy

D Macpherson et al. BJA Educ. 2022 May.
No abstract available

Keywords: anaesthesia; analgesia; anatomy; epidural; obstetrical.

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Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Fig 1
Fig 1
Characteristic features of a typical (A, B) cervical, (C, D) thoracic and (E, F) lumbar vertebra, in (A, C, E) posterior and (B, D, F) right lateral views, respectively. Vertebral bodies (VB), laminae (L), vertebral foramen (white asterisks) and spinous processes (black arrows) are indicated. Articular processes (black arrowheads) in cervical vertebrae are oriented in an oblique but shallow direction in order to enable rotational movement of the cervical vertebral column, becoming more vertical in thoracic and lumbar vertebrae. White arrows show transverse processes in cervical and thoracic vertebrae and costal process of a lumbar vertebra. The mark on the cloth represents 10 mm.
Fig 2
Fig 2
(A) Posterior aspects of the vertebral laminae (black arrowheads) and the ligamentum nuchae (white arrow). Black arrow: spinous processes covered by the supraspinous ligament, O: occipital bone, white arrowhead: right external ear. (B) Opening of the epidural space after laminectomy in the thoracic and lumbar region. White arrows show emerging spinal nerve roots covered by dura. DS: dural sac. (C) Internal aspect of the posterior wall of the vertebral canal (removed after laminectomy and held by the spinous processes). In the area indicated by the black arrow, epidural fat and the venous plexus can be seen. (D) Image shows a close-up (plexus veins marked by black arrows, surrounded by epidural fat marked by black arrowheads). In the lower part of image (C), the epidural content has been removed to expose the anterior aspect of the vertebral laminae (white asterisks) and the ligamenta flava (black asterisks). Image (E) shows a close-up of this area.
Fig 3
Fig 3
(A) Opening of the dural sac (white arrows) to expose arachnoid mater (AM). The white arrowhead shows where the arachnoid mater has been incised to expose the cobweb-like structure of the subarachnoid space and the underlying pial surface of the spinal cord, shown as a close-up in image (B). The black arrowhead in (B) shows a point of adhesion of the dura and arachnoid mater in which the two layers have not been peeled off each other. Image (C) exposes the pial surface of the posterior aspect of the spinal cord (SC) after removal of arachnoid mater. The white arrow shows a posterior spinal nerve root. The white arrowhead shows a posterior root, incised and retracted, revealing the denticulate ligament (black arrowhead) and an anterior spinal nerve root (black arrow). Image (D) shows the conus medullaris of the spinal cord (SC) with cauda equina (white arrows) and filum terminale (black arrow). In image (E), removal of a segment of spinal cord (SC), dural sac and arachnoid mater, exposes the posterior longitudinal ligament (black asterisk) projecting into the anterior compartment of the epidural space. White arrows indicate incision points of dura and arachnoid mater.
Fig 4
Fig 4
This cross-sectional image of the vertebral canal shows the path a Touhy needle takes when accessing the epidural space from the midline. From the surface, the needle traverses the skin, fat and subcutaneous tissue. The first spinal ligament engaged is the supraspinous ligament, followed by the interspinous ligament as the needle passes between two spinous processes. The last ligament engaged is the ligamentum flavum (seen here in light blue). The tip of the needle is shown in the epidural space (orange). The epidural space surrounds the dura (seen here in dark grey).
Supplementary Fig S1
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Supplementary Fig S6
Supplementary Fig S6
See this image and copyright information in PMC

References

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