According to a study published in the journal 'Pain and Therapy', the caudal approach with adjustable catheter portrays similar but is more effective for acute severe radicular pain than the other epidural injections methods. It is extremely target-specific and hence, allows the use of small doses of corticosteroids and also makes the procedure free from the risk of significant complications.

The acute lumbosacral radicular syndrome is often a medical disorder of arduous management. Epidural steroid injection is beneficial for the herniated disc and radiculitis. Usually, the transforaminal approach is considered more effective and target-specific, but it can cause permanent lower extremity paralysis. A caudal approach with an adjustable catheter has been extensively used in adhesiolysis in chronic low back pain. However, there are no reports of its use in acute radicular pain.  Maria Clemente et al. aimed to examine the clinical effectiveness of epidural steroid injection by a caudal approach with an adjustable catheter in patients suffering from severe acute radicular pain. A total of 55 patients with severe acute radiculopathy were treated with epidural steroid injection by an epidural catheter whose tip can be directed laterally on the selected site. After 1, 3, 6, and 12 months, the Numerical rating scale (NRS), pain relief, and analgesic consumption were observed. The secondary outcomes comprise of analgesic consumption (AC) and functional recovery (FR). There was a significant reduction of NRS score that was constant every 12 months. The pain relief was good after 1 month and ameliorated further after 3 months. Few patients observed poor pain relief and only 3 patients relapsed. At the 12th month, more than 70% of patients were drug-free. 

The authors explained, "Larger studies and clinical trials should be performed to confirm our preliminary data."