Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks for chronic pain after inguinal hernia repair

PURPOSE: The aim of this study was to evaluate the outcome of ilioinguinal and iliohypogastric nerve blocks in patients with chronic pain after herniorrhaphy, by comparing nerve stimulator and ultrasound guidance to administer the block.

METHODS: A total of 43 patients who received nerve blocks for chronic inguinal post-herniorrhaphy pain received standardized questionnaires. Nerve stimulator-guided blocks were performed prior to January 2009, and thereafter, ultrasound-guided blocks were performed using a local anaesthetic solution and a corticosteroid.

RESULTS: The questionnaire was completed by 38 patients (88 %). The inguinal hernia repair was performed for a median 16 months (range 3-219) ahead of the nerve blocks. A median of 2 pain treatments (range 1-7) was calculated. Median follow-up was 21 months (range 3-68). According to the DN4, 21 patients (55.3 %) no longer reported neuropathic pain. Subjectively, 32 % no longer reported moderate-to-severe pain. After ultrasound-guided blocks, a higher VAS score (at rest and during activities), a higher proportion of daily pain and more anxiety and depression are reported compared to blocks performed after nerve stimulator guidance.

CONCLUSIONS: Ilioinguinal/iliohypogastric nerve blocks can be effective to treat chronic inguinal pain following surgery of the groin. The use of ultrasound was not superior to nerve stimulator-guided blocks. These blocks could be considered prior to more invasive procedures such as neurectomy.