Safety and efficacy of ilioinguinal and iliohypogastric nerve blocks for treatment of pelvic pain

Objective: To assess the safety and efficacy of ilioinguinal/iliohypogastric nerve blocks for patients with lower abdominal wall pain in a gynaecology setting. Methods: A retrospective chart review of 131 patients who received ilioinguinal/iliohypogastric nerve blocks at a tertiary referral centre for pelvic pain between 1 January 2012 and 13 July 2017 was performed. Patient demographics, history, examination findings and block data were extracted. Chi-square and Mann-Whitney U tests explored differences in patient characteristics between patients with and without effective response to their initial ilioinguinal/iliohypogastric nerve block. Results: A total of 465 ilioinguinal/iliohypogastric nerve blocks were performed among patients. The effect of the initial block was available for 99 out of 131 patients. Of these patients, 70% (n = 69) reported a great improvement in pain, 9% (n = 9) some improvement in pain, 18% (n = 18) no response and 3% (n = 3) worsening of pain. A significantly greater number of patients who were not responsive to their first block reported unilateral pain (p = 0.040) and had a history of vulvodynia (p = 0.038) when compared to patients who were responsive to their first block. Seven patients (5%) reported minor adverse events related to blocks. Conclusion: Ilioinguinal/iliohypogastric nerve blocks provide pain relief for those with pelvic pain localized to the lower abdominal wall, with a low rate of minor adverse events.