Lumbar epidural steroid injections (LESIs) are associated with a heightened risk for infection after lumbar spine decompression surgery, a new meta-analysis shows.

In a review that included more than 174,000 total patients, those who received a LESI within 6 months before their lumbar spine decompression surgery had more than a twofold risk of developing an infection postoperatively compared with patients who did not receive such an injection.

“Many patients with compressive lesions, such as foraminal stenosis or spinal stenosis, have significant pain, and it’s not uncommon for them to receive an epidural steroid injection prior to an elective operation,” lead author W. Michael Hooten, MD, president of the American Academy of Pain Medicine (AAPM) and professor of anesthesiology at the Mayo Clinic, Rochester, Minnesota, told Medscape Medical News.

“However, as our study shows, receipt of that injection is associated with over twice the risk of developing a postoperative infection,” Hooten said.

The findings were presented this month at the AAPM 2022 Annual Meeting in Scottsdale, Arizona.

Greater Risk Closer to Surgery

Hooten and his team conducted a literature search and identified four studies that reported on the association of preoperative LESIs with postoperative infection.

The studies included 24,191 patients who received LESIs and 149,942 patients who did not. The latter served as the control group.

The analysis showed that risk for infection was greater when injections were given closer to time of surgery.

The incidence of postoperative infections was significantly greater in patients receiving LESIs less than 1 month prior to lumbar spine decompression surgery vs the control group (P = .01).

Similarly, the incidence of postoperative infections was significantly greater if patients received their injections within 1-3 months before their surgery compared with members of the control group (P = .05).

No significant difference in postoperative infections was observed in patients receiving injections within 3 to 6 months of their surgery (P = .07).

Nevertheless, overall, patients receiving LESIs anytime within the 6-month period before their lumbar spine decompression surgery were 2.24 times more likely to develop postoperative infections compared with those who had not received the injections (P = .0003).

Long Half-Life, Immunosuppression

The risk for infection is most likely due to the immunosuppressive effects of steroids, Hooten noted.

He added that in his team’s previous research, they reported the half-life of epidural administration of triamcinolone is over 253 hours, “which is substantial.”

In addition, immunosuppression “is a known effect of steroid administration,” whether taken orally, intravenously, or, as the current analysis suggests, administered epidurally.

“The steroids are in the lumbar spine for a very long period of time, so this is the most likely mechanism for the occurrence of infection,” said Hooten.

This risk should be considered in patients who may be planning to go for elective lumbar spine decompression surgery, he added.

Hooten noted the purpose of the analysis was to raise awareness about this type of complication, not only among pain medicine practitioners but also among spine surgeons.

“If I see somebody in the clinic today who has a lumbar spine stenosis, I can give an epidural for pain relief but I don’t know if that person will go to see a spine surgeon in the next 30 to 60 days, who will then do an operation. But if the spine surgeon is aware of this risk, they could suggest delaying the operation as long as possible, especially as the risk seems to reduce or decline over time,” he said.

Clinically Important

Commenting on the study for Medscape Medical News, Ann Hansen, DVM, MD, a pain and internal medicine specialist in Ketchum, Idaho, agreed it is important for clinicians to be aware of the associated risks of steroid epidural injections.

“This is a timely meta-analysis focused on a clinically important topic,” said Hansen, who was not involved with the research.

“Given the widespread application of spinal interventions, it is important for primary care providers, surgeons, and pain specialists to understand the risks and benefits of these procedures,” she added.

Hansen noted LESIs are frequently performed for therapeutic purposes or in the context of preoperative diagnostic algorithms — and are generally considered to be safe when administered by specialists following modern standards of care.

“We recognize that intra-articular steroids are contraindicated within 3 months prior to joint surgery, but it is still accepted practice to instill epidural steroids prior to planned lumbar spine decompression surgery,” she said.

“And, as this meta-analysis documents, there is an increased risk of infection in patients receiving the steroids within 6 months of surgery. Further research is warranted to assess the impact of variables and to substantiate the conclusion,” she added.

Hansen noted the cornerstone of high-quality patient care includes shared decision-making, including a forthright discussion of the clinical diagnosis, treatment options, potential outcomes, and known complications.

“An educated, informed patient is empowered to make the most appropriate personal health decisions and to engage in longitudinal care with a trusted provider. Pain specialists must have a good understanding of the entire spectrum of multidisciplinary pain care to best advise their patients,” she concluded.

Hooten and Hansen have disclosed no relevant financial relationships.

American Academy of Pain Medicine (AAPM) 2022 Annual Meeting. Presented March 19, 2022.