Influence of needle-insertion depth on epidural spread and clinical outcomes in caudal epidural injections: a randomized clinical trial

Abstract

BackgroundA caudal epidural steroid injection (CESI) is a commonly used method to improve symptoms of lumbosacral pain. We compared the achievement of successful epidurograms and patient-reported clinical outcomes following different needle-insertion depths during CESI.MethodsFor the conventional method group, the needle was advanced into the sacral canal. For the alternative method group, the needle was positioned immediately after penetration of the sacrococcygeal ligament. Epidural filling patterns and vascular uptake during fluoroscopy were determined to verify successful epidural injection. Procedural pain scores were investigated immediately after the procedure. Pain scores and patient global impression of symptom change were evaluated at 1-month follow-up.ResultsAssessments were completed by 127 patients (conventional method, n=64; alternative method, n=63). The incidence of intravascular injection was significantly lower in the alternative method group than in the conventional method group (3.2% vs 20.3%, P=0.005). Procedural pain during needle insertion was significantly lower in the alternative method group (3.7±1.3 vs 5.3±1.2, P<0.001). Epidural contrast filling patterns were similar in both groups. One-month follow-up pain scores and patient global impression of symptom change were comparable in both groups.ConclusionCompared with the conventional method, the alternative method for CESI could achieve similar epidural spread and symptom improvement. The alternative technique exhibited clinical benefits of a lower rate of intravascular injection and less procedural pain.

The Influence of Ultrasound-Guided Technique Using a Catheter-Over-Needle on the Incidence of Accidental Intravascular Injection during Caudal Block-A Retrospective Case Series Study

“…Third, the epidural venous plexus is gathered at the anterior part of the sacral canal and ends at the S4 level or lower [ 17 ]. In the conventional technique, the needle comes into contact with the anterior wall of the sacral spine because of the kyphotic nature of the sacrum [ 10 , 11 ]. Doo et al [ 11 ] reported that intravascular injection incidences during a US-guided conventional technique with a disposable nerve blockade needle (25-gauge, 5 cm short-bevel needle) was 24.0% (6 of 25), as confirmed by fluoroscopy.…”

“…Doo et al [ 11 ] reported that intravascular injection incidences during a US-guided conventional technique with a disposable nerve blockade needle (25-gauge, 5 cm short-bevel needle) was 24.0% (6 of 25), as confirmed by fluoroscopy. Park et al [ 10 ] reported that intravascular injection occurrences were 20.3% (13 of 64) during a fluoroscopically guided conventional technique using a spinal needle (22-gauge, 8 cm Quincke) advanced to the mid-S3 level. They mention that unintentional intravascular injection might be caused by needle trauma in the vessel-rich zone in the sacral canal and direct needle contact to the sacral bone during the execution of the conventional technique.…”

“…The final level of needle tip could affect contrast distribution and analgesic effects. Additionally, Park et al [ 10 ] reported that they saw a ventral epidural spread above the S1 in 94.1% of patients when they had used 15 mL of contrast through a 22-gauge spinal needle advanced to the mid-S3 level. The needle gauge did not seem to affect the level of epidural spread in the caudal blocks [ 13 ].…”

“…Furthermore, a lack of blood flashback on pre-injection aspiration is not a reliable indicator of extravascular needle placement [ 7 , 8 , 9 ]. The occurrence of inadvertent vascular injection during caudal block with the conventional technique was 10.9–24.0% [ 8 , 10 , 11 ]. Previous studies of the conventional technique have noted intravascular injection occurring with a stiff metallic beveled needle.…”

Low incidence of vascular uptake during ganglion impar sympathetic nerve blocks for coccydynia

“…Multiple prior publications regarding contrast injection prior to medication injection demonstrated rates of vascular uptake of contrast at various injection sites. Examples include vascular uptake rates of 20% for caudal epidural steroid injections[ 4 ] and 17%, 6%, 8%, and 21%, for sacral, lumbar, thoracic, and cervical transforaminal epidural injections, respectively. [ 5 ]…”