Fluoroscopic Assessment Of Epidural Contrast Spread After Caudal Injection

Abstract

Objective: To assess and document using fluoroscopy the epidural flow patterns and the volume of injectate required to reach the L4/5 and L5/S1 disc levels after caudal epidural steroid injection.

Design: Prospective observational case series.

Methods: 100 consecutive patients who had radicular pain average age 55.7 ±17.9 years underwent caudal epidural steroid injection with contrast enhancement and fluoroscopic guidance. The following data was collected: epidural contrast volume required to reach L5/S1 and L4/5 levels; whether contrast flow pattern is dorsal, ventral, or both; left, right, or bilateral; result of aspiration, presence or absence of vascular pattern or dural puncture.

Results: 99% reached L5/S1 with 2.8 ±1.1 ml of contrast, 85% reached L4/5 with 4.8 ±1.5 ml of contrast. Flow was bilateral in 68%, dorsal in 31%, ventral in 35%, and dorsal and ventral in 34%. Vascular pattern was noted with negative aspiration in 2%.

Conclusion: The data suggests that 8 ml of injectate delivered via the caudal route will usually reach the L4/5 and lower levels. Fluoroscopy and contrast are useful in caudal epidural injection to assure that injectate flow is epidural and reaches the desired region.

Key Words::

• radicular pain
• epidural steroid
• lumbar disc prolapse
• fluoroscopy