To the Editor:
In a consensus opinion by the multidisciplinary group regarding the safeguards to prevent neurological complications after epidural steroid injections, Rathmell et al.1 correctly point out that the number of cases with catastrophic neurological injury related to epidural steroid injection is not trivial. Whereas spinal cord and brain infarction secondary to particulate steroid embolization is an important concern, it is to be noted that in a recent analysis of malpractice closed claims, neurological injuries related to direct needle trauma outnumbered the injuries related to spinal cord or brain embolic infarction.2 In this analysis, fluoroscopy was used in 76% of cases in which neurological injury occurred; hence, mere use of fluoroscopy does not guarantee safety.2 In the current consensus, the authors correctly point out that in addition to the anteroposterior view, the lateral or the contralateral oblique (CLO) view may be used to gauge needle depth.
Given that devastating injuries continue to occur despite the use of fluoroscopy, an important safety question is, “does a lateral fluoroscopic view reliably visualize the needle tip and estimate the depth of insertion particularly at the C7-T1 level?” The limitation of the lateral view in providing good needle tip visualization when accessing cervical or cervicothoracic epidural space by the interlaminar approach was highlighted by our study where the needle tip was not visualized or not well visualized in the lateral view in 16 of 24 cases in the low cervical and upper cervicothoracic spine.3 Furthermore, the lateral view did not provide consistent location of the needle tip in the epidural space with respect to bony landmarks.3 These limitations of the lateral view could account for some cases of spinal cord injury despite the use of fluoroscopy. In contrast to this, the CLO view provided crisp visualization of the needle tip and less variability in needle tip location when visualized at an angle of 50 degrees. Based on this, we propose that the preferred use of the CLO view for depth of insertion during interlaminar epidural access has the potential of reducing complications related to direct spinal cord injury. This is likely to be especially true in cases where the needle tip is not well visualized in the lateral view. Correct use of the CLO view as well as the pitfalls of the lateral view should be taught routinely in fellowships and in society educational workshops to promote the safe access to the epidural space.
The authors declare no competing interests.