CHARLOTTESVILLE, VA (MARCH 14, 2017). Research conducted at the University of Virginia suggests that patients may wish to take a 1 to 3 month break from lumbar epidural steroid injections (LESIs) before undergoing lumbar spinal fusion surgery. Why? An increased risk of infection has been identified when LESIs are administered within 3 months prior to surgery. Full details can be found in the article "The impact of preoperative epidural injections on postoperative infection in lumbar fusion surgery" by Anuj Singla, M.D., and colleagues, published online today in the Journal of Neurosurgery: Spine.
Background
Lumbar epidural steroid injections (LESIs) are administered to patients with low-back pain and associated leg pain. The injection delivers corticosteroid medications to the epidural space, an area just outside the spinal sac containing the spinal cord and nerve roots. Once there, the medicine's anti-inflammatory effects reduce nerve root inflammation, local ischemia, and the pain resulting from both. LESI is a standard nonsurgical option to treat persistent and severe low-back pain and radicular leg pain (sciatica). LESI treatment is generally considered safe, although sometimes complications, such as infection, nerve damage, or bleeding, can occur. In some cases lumbar spinal fusion surgery must be performed if LESI fails to provide durable pain relief.
Lumbar spinal fusion surgery is performed to stabilize parts of the spine that, through injury or age-related degeneration, may have weakened, shifted location, or changed shape, causing inflammation, pain, and/or reduced function. During surgery, a bone graft is used to bind two adjacent vertebrae together, eliminating painful movement in that portion of the spine.
The Study
Using the nationwide, insurance-based PearlDiver patient record database, the authors collected information on patients 65 years of age or older who had undergone a one-level or two-level lumbar spinal fusion. The search identified 88,540 patients. Of these, 1,699 patients received LESI within 1 month before surgery, 5,491 patients received the injection 1 to 3 months before surgery, and 10,493 patients received the injection 3 to 6 months before surgery; the remaining 70,857 patients did not receive LESI prior to lumbar surgery.
The researchers reviewed data on patient outcomes during the first 90 days following surgery, paying specific attention to incidences of postoperative infection. They found infection rates of 3.9% in patients who underwent surgery within 1 month after LESI, 2.2% in patients who underwent surgery 1 to 3 months after LESI, and 1.3% in patients who underwent surgery 3 to 6 months after LESI. The infection rate in patients who did not receive LESI prior to surgery (the control group) was 1.5%. The differences in infection rates between both groups of patients who underwent surgery within 3 months of receiving LESI and the control group were statistically significant. There was no significance in the difference in infection rates between patients who underwent surgery 3 to 6 months after receiving LESI and the control group of patients who did not receive LESI prior to surgery.
These findings show a significant added risk of infection when LESI is administered less than 3 months before the patient undergoes lumbar fusion surgery. The risk of infection is greatest when LESI is administered within 1 month before surgery.
The importance of this study lies both in the large number of patient records reviewed and the timing of injections that were examined. Previous studies indicated that administration of LESI shortly before lumbar spinal fusion surgery may result in an increased rate of infection, but fewer patient records were reviewed and varying times of injections were not compared. In the present study, the researchers found that the incidence of infection was highest when LESI was administered within 1 month before surgery and lowest when administered 3 to 6 months before surgery. The researchers pose the possibility that the immunosuppressive effect of LESI may wear off after a specific time and no longer increase the risk of infection. They admit that a very brief time between LESI and surgery could also indicate that patients had more severe symptoms indicating a greater disability and longer operative time, which could lead to a higher risk of infection. The researchers encourage future in-depth studies.
The researchers recommend that their findings be included when advising patients who have received LESI on the timing of future lumbar fusion surgery. They conclude, "Although the overall infection rate remains low despite the use of preoperative LESIs, increasing the time interval to more than 3 months from injections to surgery may help to reduce this increased risk."
When asked about the importance of this study, Dr. Singla responded, "Patients tend to undergo LESI routinely before surgery, which was always considered a risk for infection because of its steroidal content. The results of this study provide a clear association between the timing of the injections and the risk of infection after subsequent spinal fusion surgery."
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Singla A, Yang S, Werner BC, Cancienne JM, Nourbakhsh A, Shimer AL, Hassanzadeh H, Shen FH: The impact of preoperative epidural injections on postoperative infection in lumbar fusion surgery, Journal of Neurosurgery: Spine, published today online, ahead of print, March 14, 2017; DOI: 10.3171/2016.9.SPINE16484.
Disclosure: Dr. Shimer is a consultant for NuVasive and serves on the speaker board for Stryker. Dr. Hassanzadeh is a consultant for NuVasive and receives support for non-study-related clinical or research efforts from Orthofix and Pfizer. Dr. Shen is a consultant for DePuy Synthes, Medtronic, and Globus.
For additional information, please contact: Ms. Jo Ann M. Eliason, Communications Manager, JNS Publishing Group, One Morton Drive, Suite 200, Charlottesville, VA 22903; Email jaeliason@thejns.org; Phone 434-982-1209.
The Journal of Neurosurgery: Spine is a monthly peer-reviewed journal focused on neurosurgical approaches to treatment of diseases and disorders of the spine. It contains a variety of articles, including descriptions of preclinical and clinical research as well as case reports and technical notes. The Journal of Neurosurgery: Spine is one of four monthly journals published by the JNS Publishing Group, the scholarly journal division of the American Association of Neurological Surgeons. Other peer-reviewed journals published by the JNS Publishing Group each month include the Journal of Neurosurgery, Neurosurgical Focus, and the Journal of Neurosurgery: Pediatrics. All four journals can be accessed at http://www.thejns.org.
Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 8,300 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system including the brain, spinal column, spinal cord, and peripheral nerves. For more information, visit http://www.AANS.org.