Superior Hypogastric Nerve Block as Post-Uterine Artery Embolization Analgesia: A Randomized and Double-Blind Clinical Trial.

Purpose To evaluate the effectiveness of superior hypogastric nerve block (SHNB) in reducing narcotic use after uterine artery embolization (UAE). Materials and Methods This study was a prospective, randomized, double-blind, parallel clinical trial in patients referred to a tertiary care university teaching hospital for UAE. Forty-four participants were enrolled (mean age, 46 years; range, 32-56 years). No consenting patient was excluded. All participants were randomized 1:1 to undergo either a sham procedure or SHNB. There were 22 participants in each group. One participant was lost to follow-up regarding home survey results. Use of narcotics and antiemetics was recorded in-hospital. Pain scores were recorded at home for 10 days with use of a visual analog scale (range, 1-10). Statistical analysis was performed by using the t test and χ test, with P < .05 considered indicative of a statistically significant difference. The full study protocol can be found at www.clinicaltrials.gov (NCT02270255). Results Participant demographic characteristics, fibroid volume, symptoms, and perceived sensitivity to pain were similar in both groups. Immediately after embolization, the pain score was lower in the SHNB group than in the sham group (mean, 1.0 ± 2.1 vs 2.6 ± 2.0, respectively; P = .01). The total need for fentanyl in the postanesthesia care unit was lower in the SHNB group than in the sham group (mean, 56 μg ± 67 vs 124 μg ± 91, respectively; P = .009). The morphine-equivalent dose needed was lower in the SHNB group than in the sham group (mean, 5.1 mg ± 5.8 vs 11.0 mg ± 9.0, respectively; P = .014). Of the 22 participants in the SHNB group, five (23%) needed antiemetics versus 12 of 22 participants (55%) in the sham group (P = .03). No difference in hospital admissions was observed between the two groups, and no major complications occurred from the SHNB. Conclusion Use of superior hypogastric nerve block reduces the amount of pain-related narcotics and antiemetics after uterine artery embolization. © RSNA, 2018.