Electron Microscopy of Dural and Arachnoid Disruptions After Subarachnoid Block.
Reg Anesth Ache Med. 2017 Nov/Dec;42(6):709-718
Authors: Reina MA, Puigdellívol-Sánchez A, Gatt SP, De Andrés J, Prats-Galino A, van Zundert A
BACKGROUND: It has been customary to attribute postdural puncture headache (PDPH) incidence and severity to dimension and nature of the dural gap produced throughout main neuraxial blockade or diagnostic dural puncture. Needle orientation in relation to the path of dural fibers was considered of significance due to the propensity for horizontal bevel placement to trigger reducing relatively than splitting of the dural fibers.
METHODS: In vitro punctures of stringently quality-controlled human dural sac specimens have been obtained with 27-gauge (27G) Whitacre needle (n = 33), with 29G Quincke used parallel to the spinal axis (n = 30), and with 29G Quincke in perpendicular method (n = 40). The samples have been studied with a scanning electron microscope, and the perimeter, look, and space (%) of the lesion have been calculated.
RESULTS: When utilizing small 27G to 29G needles, neither needle tip traits nor needle orientation had a considerable bearing on the harm to dural fibers within the dural lesion. Of final significance was the attribute and dimension of the outlet within the arachnoid. Arachnoid layer lesions produced by several types of spinal needles weren’t markedly completely different.
CONCLUSIONS: Accepted theories of the etiology of PDPH should be revised. This text marks the primary time that arachnoid layer harm has been quantified. Dural fibers are likely to have adequate “reminiscence” to shut again the outlet created by a spinal needle, whereas arachnoid has diminished capability to take action. The pathogenesis of PDPH and its decision algorithm are a much more complicated course of that entails many extra “phases” of growth than hitherto imagined.
PMID: 28991062 [PubMed – indexed for MEDLINE]