Evaluation the Impact of the "Pas" Technique Versus the "Standard" Technique on Radiation Exposure

PAS Technique Protocol:

The following steps outline the PAS Technique. While the example below uses 6 injection sites, the approach can be adapted for different pain management procedures with a different number of needle injection sites as needed.

Timer: Begin stopwatch for entire procedure from start to medication insertion. Positioning: The patient is placed in a prone position on the fluoroscopic table. Time out was performed.

Skin Preparation: Clean the injection site with an antiseptic solution and drape it to maintain sterility.

Anesthesia: Administer intravenous sedation Identification of Anatomical Landmark:The spinous process was located and marked as the reference point (SP), which was then used as a guide for the following steps.

Marking Target Points: Using the spinous process (SP) as the anatomical landmark and X-ray guided fluoroscopy, Target Point 1 (TP1) was identified and its position verified. The X value (the horizontal distance from the SP to TP1) was measured. This X value was not just a guide but the exact horizontal distance used for the placement of all subsequent target points. For the vertical distance between target points, a consistent distance of 3 cm was applied. This value was determined as the average vertical distance between the target points based on prior findings.

Refer to Figure 2 for a detailed illustration of the target point positions in relation to the spinous process and the distances applied.

Horizontal Distance (X Values):

The X value represents the horizontal distance from the spinous process (SP) to each target point (TP).

The X value measured for TP1 was used as the fixed horizontal distance for all target points on both sides of the SP.

For target points on the opposite side of the SP, the same X value was mirrored.

Thus, for the entire procedure:

TP1 and TP4 were placed at an equal X distance to the right and left of the SP, respectively.

TP2 and TP5 followed the same X distance as TP1 and TP4, located on their respective sides of the SP.

Vertical Distance (Y Values):

The Y value represents the vertical distance between the target points. A consistent vertical distance was applied between the target points. This was determined as the average distance between the target points based on prior findings.

Therefore:

TP2 was positioned 3 cm below TP1. TP3 was positioned 3 cm above TP1. TP5 was positioned 3 cm below TP4. TP6 was positioned 3 cm above TP4.

Final Verification: One final fluoroscopic image was taken to verify the accurate placement of all needles at the marked target points.

**Inclusion Criteria:**

• Adult patients aged 19 and older
• No history of:
• Convictions
• Infections
• Cancer
• Contraindications for surgical procedures
• Patients scheduled for pain injections who:
• Agree to participate in the study
• Sign informed consent and IRB approval consent
• Complete preoperative, postoperative, and 1-week postoperative questionnaires
• Patients with chronic lower back pain (lasting over three months) that has not responded to conventional treatments (e.g., NSAIDs, back muscle strengthening, physiotherapy)
• Symptoms indicating facet pain, including:
• Lower back pain with or without radiation to the buttocks, thigh, or groin
• Pain increasing on hyperextension
• Pain during initial movements
• Focal tenderness over the facet joint when pressed
• Post-lumbar disc surgery patients with persistent pain but no MRI evidence of arachnoiditis or infection
• All procedures conducted under fluoroscopic guidance for spinal needle placement
• Data collection parameters:
• Gender, race, height, weight, BMI
• Radiation exposure from fluoroscopy dosage logbook
• Procedure time
• Horizontal and longitudinal distance measurements between spinal levels (in cm)
• Study period: October 1, 2023, to May 15, 2024

**Exclusion Criteria:**

• Evidence of:
• Infection (elevated WBC >12,000 or UTI)
• Neoplastic disease
• Possible pregnancy, bleeding diathesis, or anticoagulant therapy
• History of sensitivity to local anesthetics

**Preoperative and Postoperative Assessments:**

• Visual Analog Scale (VAS)
• Numeric Pain Scale
• Disability Oswestry Index questionnaires
• Additional data collection for both cohorts:
• Patient demographics (age, gender, race, height, weight, BMI)
• Radiation exposure from fluoroscopy (in mGy)
• Procedure duration
• Horizontal and vertical distance measurements (in cm) between spinal needle placements