Transforaminal Versus Interlaminar Approaches to Epidural Injections: A Comparitive Study for Symptomatic Lumbar Intervertebral Disc Herniation

Background: Transforaminal epidural steroid injections (TFESI) and interlaminar epidural steroid injections (ILESI) are commonly performed procedures for the management of unilateral lumbosacral radicular pain (LSRP) due to intervertebral disc herniations. Unilateral LSRP is thought to originate from inflammation in the proximity of a damaged intervertebral disc or a narrowed neuralforamen that irritates an exiting spinal nerve root. Aims: present study was designed to compare the efficacy of  Transforaminal Versus Interlaminar Approaches to Epidural Steroid Injections for Symptomatic Lumbar Intervertebral Disc Herniation. Methods: In a prospective study, 60 patients with low back pain were randomly allocated to one of the two groups of 30 patients each. In Group IL( interlaminar approach), with the patient in lateral position, under strict aseptic precautions, 18G Tuohy needle is placed by loss of resistance technique and confirmed using iohexol dye and 80 mg (2 mL) of methyprednisolone with 2 mL of normal saline is injected. In group TF(transforaminal approach), with the patient in prone position, under strict aseptic precautions, 23 G Quinke needle is placed in epidural space under C-arm guidance and confirmed by using Iohexol dye and 80 mg (2 mL) of   methyprednisolone with  2 mL of  normal saline is  injected. Patient monitored for 15 mins after the procedure. Pain relief assessed by using Numerical Rating Scale(NRS), Verbal Rating Scale(VRS), Straight Leg Raising Test(SLRT) etc. Results: In Group IL, NRS decreased from 7.77±1.2 (pre-procedure) to 4.73±1.1 and 4.27±1.5 at the end of 2nd and 3rd week respectively. In Group TF, NRS decreased from 7.8±1.3 (pre-procedure) to 2.77±1.7 and 2.63±1.7 at the end of 2nd and 3rd week respectively. This difference in NRS was statistically significant both at the end of 2nd week and 3rd week with a P value of 0.001 with Group TF having better pain relief. There was no statistically significant difference among the 2 groups with respect to SLRT, improvement in walking tolerance, reduction in analgesic use and reversal of paraesthesia at the end of 3rd week. Conclusions: Epidural steroid injection by transforaminal route provides better subjective pain relief in the short term