Title : Analysis for the optimal angle and injection position in retrodiscal approach transforaminal epidural steroid injection (RA-TFESI)
Abstract:
Background: Transforaminal Epidural Steroid injection(TFESI) is known to be an effective treatment for pain caused by lumbar diseases such as intervertebral disc herniation , spinal stenosis. This study aims to find out the optimal angle of needle insertion at the time of retrodiscal approach-TFESI(RA-TFESI) based on the MRI image and to identify factors affecting it. And we find out the optimal position of needle during drug injection ,measuring by the gap between the point where the needle contacts the disc and the point where the parallel lines drawn from the most swelling part of the disc.
Methods: The subjects of the present study were 250 randomly selected patients are performed TFESI via RD approach due to lumbar herniation of intervertebral disc (HIVD) or lumbar stenosis. A total of 250 patients were analyzed by dividing into three groups, L4-5 level 190 people, L5-S1 level 50 and L3-4 leve 10 people, depending on the major lesion location and observed based on the MRI image retrospectly.
Results: The average needle insertion angle and drug injection site length were 41.6±3.2° and 4.8±1.4 mm at the L3/4 level, 46.4±4.0° and 5.2±1.6 mm at the L4/5 level, 49.0±3.8° and 6.4±1.7 mm at the L5/S1 level, respectively. The average needle insertion angle and drug injection site length at overall level were 46.7±4.2° and 5.4±1.7 mm.
Conclusion: The present study was conducted to investigate the appropriate angle of needle insertion and drug insertion site in the performance of RA-TFESI in Korean patients. The results of the present study may be used as a reference for successful therapeutic outcome and we propose the need for needle with sufficient length and side hole for ideal drug injection location.
