title: Neural-Dural Transition at the Thoracic and Lumbar Spinal Nerve Roots: A Histological Study of Human Late-Stage Fetuses.
abstract: Epidural blocks have been used extensively in infants. However, little histological information is available on the immature neural-dural transition. The neural-dural transition was histologically investigated in 12 late-stage (28-30 weeks) fetuses. The dural sheath of the spinal cord was observed to always continue along the nerve roots with varying thicknesses between specimens and segments, while the dorsal root ganglion sheath was usually very thin or unclear. Immature neural-dural transitions were associated with effective anesthesia. The posterior radicular artery was near the dorsal root ganglion and/or embedded in the nerve root, whereas the anterior radicular artery was separated from the nearest nerve root. The anterior radicular artery was not associated with the dural sheath but with thin mesenchymal tissue. The numbers of radicular arteries tended to become smaller in larger specimens. Likewise, larger specimens of the upper thoracic and lower lumbar segments did not show the artery. Therefore, elimination of the radicular arteries to form a single artery of Adamkiewicz was occurring in late-stage fetuses. The epidural space was filled with veins, and the loose tissue space extended ventrolaterally to the subpleural tissue between the ribs. Consequently, epidural blocks in infants require special attention although immature neural-dural transitions seemed to increase the effect.
authors.affiliation: Department of Neurology, Wonkwang University School of Medicine and Hospital, Institute of Wonkwang Medical Science, Iksan 570-711, Republic of Korea.
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Anatomy, Histology and Embryology, Yanbian University Medical College, Yanji, Jilin, China.
authors.forename: Zhe Wu
authors.initials: ZW
authors.lastname: Jin
authors.affiliation: Department of Anatomy, Akita University School of Medicine, Akita 010-8502, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.affiliation: Maxillofacial Anatomy, Department of Maxillofacial Biology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Division of Internal Medicine, Iwamizawa Kojin-kai Hospital, Iwamizawa 068-0833, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Murakami
authors.affiliation: Department of Anatomy and Human Embryology, Institute of Embryology, Faculty of Medicine, Complutense University, Madrid, Spain.
authors.forename: Jose Francisco
authors.initials: JF
authors.lastname: Rodríguez-Vázquez
mesh_terms: D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D006651:Histocytochemistry; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D013126:Spinal Nerve Roots / Q000033:anatomy & histology*; D013904:Thoracic Vertebrae / Q000033:anatomy & histology*