Correlation between Epidurographic Contrast Flow Patterns and Clinical Effectiveness in Chronic Lumbar Discogenic Radicular Pain Treated with Epidural Steroid Injections Via Different Approaches

Abstract

BackgroundEpidural steroid injections are an accepted procedure for the conservative management of chronic backache caused by lumbar disc pathology. The purpose of this study was to evaluate the epidurographic findings for the midline, transforaminal and parasagittal approaches in lumbar epidural steroid injections, and correlating them with the clinical improvement.MethodsSixty chronic lower back pain patients with unilateral radiculitis from a herniated/degenerated disc were enrolled. After screening the patients according to the exclusion criteria and randomly allocating them to 3 groups of 20 patients, fluoroscopic contrast enhanced epidural steroids were injected via midline (group 1), transforaminal (group 2) and parasagittal interlaminar (group 3) approaches at the level of the pathology. The fluoroscopic patterns of the three groups were studied and correlated with the clinical improvement measured by the VAS over the next 3 months; any incidences of complications were recorded.ResultsThe transforaminal group presented better results in terms of VAS reduction than the midline and parasagittal approach groups (P < 0.05). The epidurography showed a better ventral spread for both the transforaminal (P < 0.001) and the paramedian approaches (P < 0.05), as compared to the midline approach. The nerve root filling was greater in the transforaminal group (P < 0.001) than in the other two groups. The ventral spread of the contrast agent was associated with improvement in the VAS score and this difference was statistically significant in group 1 (P < 0.05), and highly significant in groups 2 and 3 (P < 0.001). In all the groups, any complications observed were transient and minor.ConclusionsThe midline and paramedian approaches are technically easier and statistically comparable, but clinically less efficacious than the transforaminal approach. The incidence of ventral spread and nerve root delineation show a definite correlation with clinical improvement. However, an longer follow-up period is advisable for a better evaluation of the actual outcom.

Comparison of transforaminal verse interlaminar epidural steroid injection in low back pain with lumbosacral radicular pain: a meta-analysis of the literature

“…The targeted site of interface of the disk and the exiting root was often situated in the ventral epidural space, whereas the injectate from the interlaminar route may be prevented from diffusing from the posterior epidural space to the ventral epidural space. Nevertheless, our meta-analysis based on only three RCTs [21,30,39] suggested that the transforaminal approach was balanced with the interlaminar route for placing contrast into the ventral epidural space. This finding may be explained by the fact that the limited numbers of patients did not have sufficient power to detect differences in the ventral epidural spread between the two groups.…”

“…Four of the nine studies [26,28,31,32] performed patient blinding, and all trials demonstrated assessor blinding, with the exception of one study [32]. Regarding other bias, two studies [21,28] had been unclear. Four observational studies were assessed using NOS ( Table 3).…”

“…The available data regarding post-injection follow-up pain relief in both TFESI and ILESI group were provided in four RCTs [21,27,30,32] and two observational studies [12,33]. The outcome from the pooled analysis of four RCTs showed that patients in the TFESI group had a significant pain relief compared to those in the ILESI group (RR 1.28, 95 % CI 1.05-1.57, P = 0.01; Fig.…”

“…Three RCTs [21,30,39] presented data of ventral epidural spread. The pooled estimates did not identify statistically significant differences in the TFESI and ILESI groups by using random-effect model (RR 0.94, 95 % CI 0.74-1.19, P = 0.61, Fig.…”

“…The transforaminal approach is considered to transmit the medication more closely to the primary site of pathology, requiring less volume than the interlaminar route [20]. Moreover, multiple studies [12,[21][22][23][24][25][26][27][28] and systematic reviews [20,29] have shown that lumbar transforaminal epidural steroid injections (TFESI) to treat lumbosacral radicular pain provides superior short-term (≤1 year) pain relief and functional improvement compared with interlaminar epidural steroid injections (ILESI).…”