Don't assume that particulate clogging and artery and causing an infarct as being the only way a TF esi can cause a cord infarct. The perforating spinal arteries are small and if using a cutting needle (Quinke) and depending on size (22g worse than 25g, obviously) one could tear or cut such an artery simply by hitting it or going through it with the needle, especially if its someone who already has a propensity to vascular disease with atherosclerosis (dissection can be caused by needle trauma to a calcified artery), and especially if a difficult injection with multiple passes with the needle, turning of a bent tip needle or other trauma. Certainly injection particulate into an artery can shut down arterial flow, but certainly isn't the only way to cause arterial trauma or infarct.
I favor using dex in TF ESIs as risk reduction, but I don't assume that risk reduction gets me down to zero risk.
I'm curious what you all think regarding infraneural approach. It is less likely to hit artery but higher risk of intradiscal injection. I haven't seen any reports of infarct with infraneural TFESI but granted it is less common.
Needle position analysis in cases of paralysis from transforaminal epidurals: consider alternative approaches to traditional technique.
Atluri S1, Glaser SE, Shah RV, Sudarshan G. Author information
Abstract
BACKGROUND:
Transforaminal technique for epidural steroid injections, unlike other approaches, is uniquely associated with permanent, bilateral, lower extremity paralysis.
OBJECTIVE:
To review the literature and analyze the reported cases of paralysis from lumbar transforaminal epidural steroid injections to possibly establish a cause and to prevent this complication.
STUDY DESIGN:
Eighteen cases of paralysis from transforaminal epidural injection have been reported. We could analyze the position of the needle within the neural foramen based on the available images and/or description among 10 of these 18 cases. Five cases were performed with computed tomography guidance and 12 cases were performed with fluoroscopic guidance [unknown in one case]. Additionally, other variables associated with the procedure, including the technique, were also examined.
METHODS:
Analysis of the needle position in the neural foramen in cases of paralysis from transforaminal epidural steroid injections. This analysis is based on images and/or description provided in published reports.
RESULTS:
Paralysis in these cases seems to be associated with a well performed traditional safe triangle approach with good epidural contrast spreads. Analyzed data shows that 77.7% of the time, the needle was in the superior part of the foramen. In 71.4% of the cases, the needle was in the anterior part of the foramen. This coincides with the location of the radicular artery in the foramen. In 22.2%, the needle was in the midzone (neither in the superior nor inferior zone). No level was spared as this event occurred at every foramen from T12 to S1. Ten of these events happened during a left-sided procedure and 8 during a right-sided procedure. No relation to this complication was noted when other variables like type and size of the needles, side of the injection, local anesthetic, contrast, or volume of injectate were taken into consideration.
LIMITATIONS:
Only 18 cases of paralysis from transforaminal epidurals have been reported. Out of these, only 10 cases included images or descriptions which could be evaluated for our study.
CONCLUSION:
In light of the anatomical and radiological evidence in the literature that radicular arteries dwell in the superior part of the foramen and along with our needle position analysis, we suggest that the traditional technique of placing the needle in the superior and anterior part of the foramen must be reexamined. Alternative, safer techniques must be considered, one of which is described.