Intra-arterial lidocaine eases early pain after uterine artery embolisation, review finds

Uterine artery embolisation offers many women a minimally invasive way to shrink symptomatic fibroids while keeping the uterus intact, but the procedure has a well-known drawback: intense pain that typically flares within the first few hours afterwards. A new systematic review and meta-analysis now offers the clearest recent picture of whether an experimental analgesic trick—injecting the local anaesthetic lidocaine directly into the uterine arteries—can blunt that pain. The answer is a qualified yes, with the benefit concentrated in a narrow early window and several important caveats attached.

The review, published in CVIR Endovascular, was conducted according to the PRISMA 2020 reporting guidelines and registered prospectively with PROSPERO. The researchers searched MEDLINE, Embase and the Cochrane Library from their inception dates to 19 June 2026, combining MeSH terms and free-text keywords covering uterine artery embolisation and lidocaine. They also hand-searched the reference lists of included studies. From 123 database records, screening and full-text assessment left eight studies that met the eligibility criteria, together enrolling 692 patients.

The evidence base was a mix of designs. Four of the eight studies were randomised controlled trials and four were retrospective cohort studies, conducted across five countries: China, the United States, Canada, Japan and the Republic of Korea. Seven studies examined intra-arterial lidocaine during embolisation for symptomatic uterine fibroids, while one involved a clinically different indication, caesarean scar pregnancy. Pain was measured with a visual analogue scale in six studies, a numerical rating scale in one, and a six-level ordinal pain scale in one. Eligible studies had to enrol adult women undergoing uterine artery embolisation, use intra-arterial lidocaine as the primary pain strategy, and report at least one prespecified outcome.

The technique itself is straightforward in concept. Lidocaine is delivered through the microcatheter directly into the uterine arterial circulation, either during embolisation or immediately afterwards, so the anaesthetic reaches the tissue territory that is about to become ischaemic. Post-embolisation pain is attributed to ischaemia caused by occluding the uterine arteries, and it is thought that lidocaine suppresses the pain response in the remaining myometrial branches that are preserved. Because the worst pain typically occurs within the first several hours after the procedure, an agent acting at that site and time is an attractive candidate.

The meta-analysis found two statistically significant benefits. At four hours after the procedure, intra-arterial lidocaine was associated with significantly lower pain scores than control across four studies, with a mean difference of −1.07 (95% confidence interval −2.13 to −0.01; P = 0.05), though heterogeneity was high (I² = 82%). The second benefit concerned the maximum pain experienced during the first 24 hours: pooling six studies with 511 patients, the mean difference was −1.37 (95% CI −2.30 to −0.45; p = 0.004), again with substantial heterogeneity (I² = 81%). Because not every study reported a maximum score directly, the authors took the highest pain score across the time points each study reported.

Outside that early window, the picture was flat. No significant differences emerged immediately after the procedure (three studies; MD −0.54; 95% CI −2.03 to 0.96; p = 0.48; I² = 96%), at seven hours (three studies, 177 patients; MD −0.36; 95% CI −0.98 to 0.26; P = 0.26; I² = 0%), or at 24 hours (four studies, 393 patients; MD −0.09; 95% CI −0.52 to 0.34; P = 0.70; I² = 24%). The authors suggest the pattern fits lidocaine’s pharmacology: the drug’s short half-life means its effect fades by the later time points, even though the first hours after embolisation are when pain peaks.

Reduced pain also did not translate into reduced opioid use. Five studies with 430 patients entered the meta-analysis of 24-hour morphine consumption, which showed no significant difference between groups (MD −2.00 mg; 95% CI −5.08 to 1.08; P = 0.20; I² = 79%). Two further studies used different opioids and could not be pooled: one reported higher 24-hour fentanyl consumption in the lidocaine group (1037 ± 573 µg versus 881 ± 419 µg), while another reported lower 24-hour sufentanil consumption (38.3 ± 6.25 mg versus 45.7 ± 6.51 mg). Similarly, two studies with 127 patients reported 24-hour CRP and white blood cell counts, and neither inflammatory marker differed significantly between groups. The authors attribute the opioid finding partly to lidocaine’s short duration of action and to variation in opioid protocols across institutions.

Safety signals were broadly reassuring but unevenly documented. Serious adverse events were uncommon, and most studies reported no major procedure-related complications attributable to lidocaine. One study described transient bradycardia with loss of consciousness during administration, which resolved after atropine. The most striking exception came from one of the earliest studies in the field, from the early 2000s, which reported severe vasospasms in 70% of patients and was terminated early; subsequent studies did not reproduce those findings, though two later studies reported mild vasospasm without severe complications. The authors caution that firm safety conclusions cannot be drawn because reporting was inconsistent and sample sizes were limited. Concerns about vasospasm matter beyond safety alone, since spasm could theoretically impair delivery of embolic material and the success of the intervention.

Heterogeneity was a recurring theme in the analysis, and the authors probed it systematically. Lidocaine protocols varied widely across studies, with concentrations from 0.5 to 2%, doses from 40 to 200 mg, injection volumes from 4 to 20 mL, and different embolic agents; some studies gave lidocaine during the procedure alongside the embolic agent while others gave it immediately afterwards. In a sensitivity analysis, excluding the study involving caesarean scar pregnancy—a clinically distinct population—greatly reduced heterogeneity while preserving the pooled effect: the four-hour pain estimate strengthened to MD −1.52 (95% CI −2.58 to −0.46; p = 0.005) with heterogeneity falling from I² = 82% to 56%, and the maximum 24-hour estimate grew slightly to MD −1.71 (95% CI −2.84 to −0.57; p = 0.003). Because relatively few studies were available, subgroup analyses of the procedural variables were not feasible.

Risk of bias added further caution. Among the four non-randomised studies, two were judged to have a serious risk of bias and two a moderate risk, using the ROBINS-I tool; among the four randomised trials, assessed with the Cochrane Risk of Bias 2 tool, one was judged low risk across all domains and three raised some concerns. The authors also note the modest sample size—eight studies and 692 patients—limited statistical power, and that the findings should be interpreted with caution. Their conclusion positions intra-arterial lidocaine as an adjunct to existing pain management protocols rather than a replacement for systemic analgesia, offering meaningful early pain relief with a favourable but incompletely characterised safety profile. They call for larger randomised controlled trials using standardised lidocaine protocols and reporting scales, and point to one intriguing direction: a single case report of intra-arterial ropivacaine, a longer-acting agent, suggests that longer-lasting drugs might address the principal limitation the review identified.

Subject of Research: Intra-arterial lidocaine for pain management during uterine artery embolisation

Article Title: Intra-arterial lidocaine as a pain management strategy for uterine artery embolisation: a systematic review and meta-analysis

Article References: Haridasan, T., Kena, A., Nguyen, L., & Tan, K. T. (2026). Intra-arterial lidocaine as a pain management strategy for uterine artery embolisation: a systematic review and meta-analysis. CVIR Endovascular, 9(1), Article 121. https://doi.org/10.1186/s42155-026-00771-y

Image Credits: AI Generated

DOI: 10.1186/s42155-026-00771-y

Keywords: uterine artery embolisation, intra-arterial lidocaine, uterine fibroids, post-procedural pain, systematic review, meta-analysis, pain management, opioid consumption, vasospasm, interventional radiology, lidocaine, PROSPERO