Seven studies (3,314 participants) were included. Three studies (n=933) were RCTs, three (n=2,291) were prospective cohort studies and one (n=90) was a retrospective cohort study.
Based on the pooled results of the RCTs which compared ilioinguinal nerve identification and division with ilioinguinal nerve identification and preservation, there was no significant difference in the percentage of people who had reported pain at 6 months after surgery. However, in the retrospective cohort study, a significantly lower percentage of people who had ilioinguinal nerve identification and division reported pain at 6 months (3%) compared with people who had ilioinguinal nerve identification and preservation (26%).
There was a significantly lower incidence of pain reported by people who had had identification and preservation of all inguinal nerves in both prospective cohort studies (1.6% and 0%, respectively) compared with people in whom no nerve had been identified (3.7% and 4.7%, respectively).
Pain was also reported to be significantly lower in the prospective cohort study of people in whom there had been identification and facultative pragmatic division of the genitofemoral nerve (1.4%) compared with people in whom there had been no identification of the genital branch of the genitofemoral nerve (4.2%).