Can epidurals manage LDH-related sciatica?

Transforaminal epidural steroid injection (TFESI) showed promise for the management of radicular pain/uncomplicated sciatica secondary to lumbar disc herniation (LDH), the phase III NERVES trial has shown.

“For the first time, NERVES reports that use of TFESI as the initial invasive treatment is similarly effective to surgery at reducing pain and disability from sciatica with symptom duration between 6 weeks and 12 months,” said the researchers.

Treatment outcomes for LDH are generally favourable, with most patients improving with conservative care within a year or two. [N Engl J Med 2007;356:2245-2256] However, if not promptly managed, loss of livelihood is likely, as most patients are typically between 40 and 45 years. [BMJ 2007;334:1313-1317, BMJ 2019; 367: l6273] “The main aim of treatment [is] to relieve sciatica symptoms … as quickly and safely as possible,” said the researchers.

Severe cases of sciatica often require steroid injections or surgery upon failure of analgesics and lifestyle modifications. Despite favourable outcomes with surgery, [Health Technol Assess 2011;15:1-578] the procedural and hospitalization costs can be a drawback, averaging ~£4,500 in the UK (for a 2-night hospitalization) vs £700 for TFESI. [https://webarchive.nationalarchives.gov.uk/20200501111106/https://improvement.nhs.uk/resources/reference-costs, accessed June 30, 2021]

TFESI is a newer and more precise treatment option, but evidence on its efficacy and cost-effectiveness is limited. “There is considerable uncertainty about the clinical effectiveness of epidurals in sciatica vs surgery for LDH treatment … The optimal invasive treatment for sciatica secondary to LDH [thus continues to remain] controversial,” said the researchers.

The team evaluated 163 individuals who had MRI-confirmed non-emergency sciatica secondary to LDH with symptom duration between 6 weeks and 12 months, and had leg pain that was unresponsive to noninvasive management. Participants were randomized 1:1 to receive either TFESI* or standard open surgical microdiscectomy and followed for 54–62 weeks. [Lancet Rheumatol 2021;3 e347–e356]

Mean improvement in ODQ** scores was similar between TFESI and surgery at week 18 (24.52 vs 26.74 points). A comparison between study arms generated an estimated treatment difference of –4.25 points (95 percent confidence interval, –11.09 to 2.59; p=0.22).

Eight adverse events were reported in the TFESI arm, as opposed to 18 in the surgery arm. Of these, four were serious – all in the surgery arm.  “[The] complications of surgery were significant, offsetting any benefits of surgery as an early treatment, whereas only minor AEs were seen with TFESI,” said the researchers.

The costs were higher for surgery vs TFESI (£6,683 vs £4,422), yielding a mean difference of £2,261, primarily owing to admitted patient care. Economic evaluation still yielded higher total costs for surgery vs TFESI (£6,919 vs £4,706). “TFESI would be less costly as an initial alternative to surgery for this condition, while achieving similar levels of improved outcomes,” they explained.

Surgery had an incremental cost-effectiveness ratio of £38,737 per quality-adjusted life-year (QALY) gained, and a 0.17-probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY compared with TFESI.

Considering the NICE*** cost-effectiveness threshold of £20,000 per QALY, and the incremental cost-effectiveness results in the current analysis, the researchers noted that “it is unlikely that surgery as a first invasive treatment would be considered a cost-effective use of NHS^# resources compared with TFESI. Our findings were robust to several modelling scenarios and assumptions, and indicated that incremental QALY gains did not justify the increased costs of surgery.”

Although surgery might still be required should TFESI fail, in view of the current findings, “we recommend that treating physicians strongly consider the use of TFESI as a stepwise invasive treatment for sciatica without neurological deficit of up to 12 months’ duration,” said the researchers.