Preeti Soni1, Jyotsna Punj1. 1. Department of Anesthesiology, Pain Medicine and Critical Care, All India Institute of Medical Sciences, New Delhi, India.
To the Editor,I read the paper “Ultrasound-guided lumbar transforaminal injection (USTFI) through interfacet approach” by Kumar et al. with great interest.[1] I congratulate the authors for this excellent report. However, we have certain queries.It is not clear from the article if the present technique for USTFI was validated in patients. It would be informative to know the number of recruited patients in which the technique was performed.The authors have mentioned use of a linear probe to perform USTFI. However, to the best of our knowledge, all but one study on USTFI have used a curved probe for the block due to deep location of neuraxial structures.[2] A linear probe was used in a study when recruited patients had body mass index of less than 25 kg/m2.[3]We are also confused about the orientation of the probe when needle was inserted. The authors mention that the probe was moved medially to laterally in parasagittal plane till trident sign (parasagittal probe orientation at the level of transverse process) was seen. However, the authors mention needle advancement between two articular processes. This is contradictory.The present technique was documented as a new technique. However, three authors previously have mentioned USTFI by similar techniques; two in out of plane interfacet approach and one by parasagittal oblique plane block.[345]The authors used fluoroscopy to confirm needle tip position by dye spread, however patterns of dye spread, which are confirmatory for the block, were not mentioned.There seems to be a typing/printing error in the figure accompanying the article.[1] Superior articular process and inferior articular process mentioned seem to be facet joint of successive lumbar verterbrae.We would also like to mention that one cited reference is not indexed in PubMed.[1]