Background and Objectives Inadvertent intradiscal injection during a lumbar transforaminal epidural steroid injection (TFESI) can be critical given the possibility of discitis and disc degeneration. Intravascular steroid injection can result in devastating neurologic complications. We sought to identify the incidence of intradiscal and intravascular injection during lumbar TFESI and determine whether an aspiration test and static fluoroscopic image can be used to predict intravascular needle placement.

Methods We evaluated 251 TFESIs in 219 patients. All TFESIs were performed by one of the authors using classic TFESI technique. After final needle position was confirmed using biplanar fluoroscopy, 1 mL of contrast was injected after negative blood or cerebrospinal fluid aspiration. Using static and real-time fluoroscopy, we assessed the incidences of intradiscal injection, blood flashback, and the presence of intravascular contrast spread.

Results The incidence of intradiscal injections was 2.3% (6/251). Six intradiscal injections were observed, all among patients who had not previously undergone disc surgery. Five intradiscal injections occurred at the L4-5 level and 1 at the L5-S1 level. The incidence of overall intravascular injection was 15.5% (39/251), of which the incidence of simultaneous vascular and epidural injection was 12.7% (32/251), whereas intravascular injection only was 2.8% (7/251). The sensitivities for detecting intravascular access via aspiration or static fluoroscopic image with contrast were 20.5% and 51.2%, respectively.

Conclusions Inadvertent intradiscal injection during TFESI is not rare. Physicians who perform interventional pain procedures should increase their awareness of related potential complications. The aspiration test and static image of fluoroscope often fail to detect the intravascular injection during the TFESI. Real-time fluoroscopy should be the gold standard for confirming intravascular injection.