초록접수[미리보기]

21KF-043
Comparison of Epidural Spreading patterns when retrodiscal approach performed with tuohy needle and the PB needle.

Geon Hyeong Bae, Eun Joo Choi, Pyung-bok Lee

Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital
Introduction
For safety considerations, many practitioners have proposed adopting the retrodiscal (infraneural) approach with the needle tip positioned into Kambin’s triangle. Although this technique may place the needle in a position with less likelihood of radiculomedullary intra-arterial cannulation, there may be other risks associated that the needle tip may unintentionally be placed too far ventrally and enter the intervertebral disc. Using the retrodiscal approach with touhy needle which is end-hole concept and sharp,the needle tip may unintentionally enter the intervertebral disc easily. The PB Needle, which is developed by supplementing this, the front part that approaches intervertebral disc is blocked. And through the analysis of lumbar MRI, the needle hole was made at the calculated distance from the average posterior disc to the upper posterior articular surface in Koreans. These features facilitate effective epidural space spreading without intradiscal injection and entry into the posterior disc probe set. The goal of this study is comparing the technical effectiveness of PB needle with touhy needle in retrodiscal approach.

Case reports
A 74-year-old woman presented with left-sided lumbar radicular pain at the L4-L5 level secondary to lateral recess stenosis. She underwent a left L4 steroid injection via Kambin \'s retrodiscal approach with touhy needle. Although anteroposterior and lateral views revealed optimal needle placement, live and postcontrast fluoroscopy revealed an unavoidable and inadvertent intradiscal spread. At the next time procedure, we performed retrodiscal approach with PB needle. The tip of the PB needles reached intervertebral disc stably, and drug injection through the needle hole effectively spread into the epidural space.

Conclusion
The PB needle effectively spread the drug into the epidural space without intradiscal injection.Furthermore, the risk of vascular injection or nerve injury may be reduced.