Comparing the effects of local intraoperative epidural use of triamcinolone-soaked Gelfoam with normal saline -soaked Gelfoam on postoperative outcomes in patients undergoing posterolateral lumbar spinal fusion surgery

This study aims to compare the effects of intraoperative local epidural administration of triamcinolone acetonide-soaked Gelfoam on postoperative outcomes of patients undergoing posterolateral spinal fusion surgery, with normal saline-soaked Gelfoam.

This study is a single center, phase 3, parallel group, double-blind, randomized, palacebo-controlled trial with 100 patients.

This study will be performed in the neurosurgery department of Shohada e Tajrish hospital. In the present study, 100 patients undergoing posterolateral lumbar spinal fusion will be randomly assigned into two groups (1:1) including treatment and control groups. Patients, outcome assessors, and data analyzers will be blind throughout the study. The surgeon who performs the operations will not be blind to the intervention and patient allocation.

Patients who undergo posterolateral lumbar instrumented spinal fusion surgery for degenerative indications will be included in the present study. Patients with non-degenerative indications such as tumor, trauma, and infection, as well as ASA physical status> 2 will be excluded.

Patients in the intervention group will receive a Gelfoam soaked in 1 ml of triamcinolone acetonide (40 mg). The Gelfoam will be placed over the nerve roots intraoperatively. Patients in the control group will receive a Gelfoam soaked in 1 ml of normal saline similarly.

The primary outcome measure of the study is postoperative pain according to the 10-point visual analog scale (VAS) at rest and with movement. Secondary outcome measures are cumulative postoperative 24 h morphine consumption, Oswestry Disability Index (ODI), length of stay, postoperative nausea and vomiting (PONV), and the incidence of postoperative complications.

Block randomization (1:1) with a block size of 4 will be performed using the SPSS 24, and sealed opaque envelopes will be used for allocation concealment. In SPSS, after dividing the study population into blocks, random numbers between 0 and 1 will be generated for each patient using RV.UNIFORM(0,1) and after determining the rank within each block, the two lower ranks will be assigned to treatment group 1, and the two upper ranks will be assigned to treatment group 2. Except for the surgeon performing the study intervention, patients, principal investigator, outcome assessors, and data analyzers will remain blind to the randomization and allocation.

Patients, the principal investigator, outcome assessors, and data analyzers will be blind to the study intervention. For allocation concealment, sealed opaque envelopes will be used (treatment 1 or 2). Due mainly to the nature of the study intervention, the surgeon will not be blind to the allocation process and intervention received by the patients and will perform the study intervention or placebo based on the study group (treatment 1 or 2). The surgeon will remain out of the process of data collection, outcome assessment, or analysis. Postoperatively, all patients, outcome assessors and analyzers, and the principal investigator will only know the study group (treatment 1 or 2) and will remain blind to the intervention performed in each group throughout the study.