An anatomical study of the intradural space.

We have previously postulated that it is possible to accidentally insert an epidural needle or catheter into the substance of the dura during attempted epidural block, creating an intradural space. It appears that injection of local anaesthetic into an intradural space leads to an initially inadequate neuraxial block but further doses may produce an extensive life-threatening block. In the laboratory, 54 samples of human thoraco-lumbar dura were obtained from six cadavers and prepared for scanning electron microscopy.

Unintentional subdural placement of epidural catheters during attempted epidural anesthesia: an anatomic study of spinal subdural compartment.

Background: Although infrequent, subdural block is a complication of epidural anesthesia with obvious implications. Knowledge of the spinal subdural compartment (dura-arachnoid interface) may help elucidate controversies arising from evidence that subdural catheter placement is feasible and may be difficult to identify clinically.

Methods: Samples of arachnoid lamina obtained during in vivo lumbosacral surgery (n = 4) and from cadavers (n = 6) were obtained and prepared for transmission electron microscopy and scanning electron microscopy.

Three-dimensional magnetic resonance image of structures enclosed in the spinal canal relevant to anesthetists and estimation of the lumbosacral CSF volume.

Three-dimensional (3D) image-reconstruction of structures inside the spinal canal certainly produces relevant data of interest in regional anesthesia. Nowadays, all hospital MRI equipment is designed mainly for clinical diagnostic purposes. In order to overcome the limitations we have produced more accurate images of structures contained inside the spinal canal using different software, validating our quantitative results with those obtained with standard hospital MRI equipment.

The ultrastructure of the human spinal nerve root cuff in the lumbar spine.

Background: Spinal nerve root cuffs may be relevant in selective nerve root and epidural blockade.

Methods: We examined the ultrastructural aspects of spinal nerve root cuffs, such as their cellular and fibrillar components, using special histological staining methods, transmission and scanning electron microscopy, from six human cadavers.

Results: The morphology of the spinal nerve root cuff resembles that of the spinal subdural compartment.

Ultrastructural findings in human spinal pia mater in relation to subarachnoid anesthesia.

Unlabelled: We examined ultrastructural details such as the cellular component and membrane thickness of human spinal pia mater with the aim of determining whether fenestrations are present. We hypothesized that pia mater is not a continuous membrane but, instead, that there are fenestrations across the pial cellular membrane. The lumbar dural sac from 7 fresh human cadavers was removed, and samples from lumbar spinal pia mater were studied by special staining techniques, immunohistochemistry, and transmission and scanning electron microscopy.