Patients with lumbar spinal stenosis will be scheduled for neuroplasty.

The patient is placed in the prone position with a pillow placed under the abdomen to correct the lumbar lordosis. After sterile preparation and draping, the epidural space via the sacral hiatus using a 16 gauge needle is accessed. Then, the Racz catheter is advanced to the site of adhesions under the fluoroscopic guidance. The target site is determined by the location of pathology on lumbar MRI, preprocedural epidurography, and clinical symptoms before the adhesiolysis. Adhesiolysis is performed through the high-volume administration of medications, which consist of a combination of a steroid, local anesthetics, hyaluronidase, and 5% hypertonic saline. As needed, the catheter remains in the epidural space for two days, with the additional injection on each of the days.

Numeric rating scale (0-10) 0=no pain, 10=worst pain imaginable

We are going to compare the change of NRS at 3 months after the procedure to the baseline value.

Oswestry disability index (10-60) 10: least score as possible, 60: most score as possible

We are going to compare the change of ODI at 3 months after the procedure to the baseline value.

Global percieved effect score by Likert scale (1-7)

1: Never satisfied with the procedure, 7: Very satisfied with the procedure

Medication quantification scale is a tool to quantify medication regimen use in chronic pain populations. We are going to use Medication Quantification scale ver 3.

The score starts at 0, and there is no specific maximum limit.

We are going to compare the change of MQS at 3 months after the procedure to the baseline value.

We are going to assess 4 variables above and then decide who is a successful responder or not at 3 months after the procedure.

We defined the successful responders as follows;

1. ≥ 50% or 4-point reduction from baseline leg Numeric rating scale and no increase from baseline Oswestry disability index and medication quantification scale and 4 points on the global perceived scale,
2. ≥ 30% or 2 points reduction from baseline numeric rating scale with any one of the following criteria: simultaneous ≥ 30% (or 10-point) reduction in Oswestry disability index from baseline, or ≥ 5 points on global perceived effects scale, or no increase from the baseline medication quantification scale.

NRS, ODI, and MQS will be evaluated before the procedure and become baseline values.

NRS, ODI, and MQS will be re-evaluated, and GPE score will be newly evaluated 3 months after the procedure.

We are going to compare the change of NRS at 1 and 6 months after the procedure to the baseline value.