Risk of femoral hernia after inguinal herniorrhaphy

Background: Small case series have suggested an increased risk of femoral hernia after previous inguinal herniorrhaphy, but no large-scale data with complete follow-up are available. Methods: Data were extracted from the Danish Hernia Database covering the interval from 1 January 1998 to 1 July 2001, and included 34 849 groin hernia repairs. Results: Of 1297 femoral hernia repairs, 71 patients had previously had an operation for inguinal hernia within the observation period. These 71 femoral hernias represented 7.9 per cent of all reoperations for groin hernia recorded in the database. The median time to reoperation for a 'recurrent' femoral hernia after previous inguinal herniorrhaphy was 7 months, compared with 10 months for inguinal recurrences. The risk of developing a 'recurrent' femoral hernia after previous inguinal herniorrhaphy was 15 times higher than the rate of femoral hernia repair in the general population. Conclusion: This study of 34 849 groin hernia repairs demonstrated a 15-fold greater incidence of femoral hernia after inguinal herniorrhaphy compared with the spontaneous incidence. These femoral recurrences occurred earlier than inguinal recurrences, suggesting that they were possibly femoral hernias overlooked at the primary operation.