Ultrasound-guided caudal epidural steroid injection for sciatica: simplicity, efficacy and safety

The possibility of precisely locating the sacral hiatus, which is greatly facilitated by echography, has rekindled interest in epidural infiltrations via this route, particularly as rare but serious complications have been reported for other epidural injection techniques, such as those using the foraminal route or particulate products. Products injected via the sacral hiatus have been shown to ascend efficiently to the lumbar spine. In recalcitrant sciatica, epidural injections of corticosteroids via the three principal routes (sacral hiatus, interlaminar, foraminal) have similar mean efficacies. Injection via the sacral hiatus, or caudal injection, has similar complications to interlaminar and foraminal injections, but these complications appear to be much rarer by this route, and avoidable if several indispensable technical precautions are applied: five-step asepsis, echographic control to check for the absence of pilonidal cysts, avoidance of canal catheterization, avoidance of the injection of air, allergenic products, anesthetic products or particulate products, and slow injection. The sacral hiatus route can be used to ensure epidural infiltration without a risk of dural leak, in patients on antiplatelet treatment, even after surgery. Further studies are required to increase the efficacy and safety of this technique and to evaluate the benefits of injecting therapeutic agents other than corticosteroids via this route.