Sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region.
OBJECTIVE
The use of ultrasound to guide peripheral nerve blocks is now a well-established technique in regional anaesthesia. However, despite reports of ultrasound guided epidural access via the paramedian approach, there are limited data on the use of ultrasound for central neuraxial blocks, which may be due to a poor understanding of spinal sonoanatomy. The aim of this study was to define the sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach.


METHODS
The sonoanatomy of the lumbar spine relevant for central neuraxial blocks via the paramedian approach was defined using a "water-based spine phantom", young volunteers and anatomical slices rendered from the Visible Human Project data set.


RESULTS
The water-based spine phantom was a simple model to study the sonoanatomy of the osseous elements of the lumbar spine. Each osseous element of the lumbar spine, in the spine phantom, produced a "signature pattern" on the paramedian sagittal scans, which was comparable to its sonographic appearance in vivo. In the volunteers, despite the narrow acoustic window, the ultrasound visibility of the neuraxial structures at the L3/L4 and L4/L5 lumbar intervertebral spaces was good, and we were able to delineate the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach.


CONCLUSIONS
Using a simple water-based spine phantom, volunteer scans and anatomical slices from the Visible Human Project (cadaver) we have described the sonoanatomy relevant for ultrasound-guided central neuraxial blocks via the paramedian approach in the lumbar region.
Department of Anesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR, China. karmakar@cuhk.edu.hk
M K
MK
Karmakar
X
X
Li
W H
WH
Kwok
A M-H
AM
Ho
W D
WD
Ngan Kee
D000775:Anesthesia, Spinal / Q000379:methods; D005260:Female; D006723:Hong Kong; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008161:Lumbosacral Region / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008297:Male; D008953:Models, Anatomic; D009407:Nerve Block / Q000379:methods*; D019047:Phantoms, Imaging; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D018084:Ultrasonography, Interventional / Q000379:methods; D055815:Young Adult