Ultrastructural Findings in Human Spinal Pia Mater in Relation to Subarachnoid Anesthesia

• Published in: Anesthesia and analgesia Vol. 98; no. 5; pp. 1479 - 1485
• Main Authors: Reina, Miguel Angel, Casasola, Oscar De León, Villanueva, M. C., López, Andrés, Machés, Fabiola, De Andrés, José Antonio
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01-05-2004; Lippincott
• Subjects: Aged; Anesthesia; Anesthesia, Spinal; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Axons - ultrastructure; Biological and medical sciences; Cadaver; Cytoplasmic Vesicles - ultrastructure; Humans; Laminectomy; Medical sciences; Meninges - ultrastructure; Microscopy, Electron; Microscopy, Electron, Scanning; Middle Aged; Mitochondria - ultrastructure; Myelin Sheath - ultrastructure; Pia Mater - cytology; Pia Mater - ultrastructure; Spinal Cord - ultrastructure; Spinal Nerve Roots - ultrastructure; Subarachnoid Space; Human; Subarachnoid; Anesthesia
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/01.ANE.0000113240.09354.E9

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. A pial layer made by flat overlapping cells and subpial tissue was identified. We found fenestrations in samples from human spinal pia mater at the thoracic-lumbar junction, conus medullaris, and nerve root levels, but these fenestrations did not appear at the thoracic level. We speculate whether the presence of fenestrations in human spinal pia mater at the level of the lumbar spinal cord and at the nerve root levels has any influence on the transfer of local anesthetics across this membrane.