Persistent neuropathic pain after inguinal herniorrhaphy depending on the procedure (open mesh v. laparoscopy): a propensity-matched analysis

A recent systematic review estimated the risk of postsurgical persistent pain (PSPP) to be 7%–12% after inguinal herniorrhaphy, depending on the method of meta-analysis.1 This finding may have relevant consequences for public health, as inguinal herniorrhaphy is one of the most frequently practised surgeries in industrialized countries. Furthermore, a proportion of the reported cases of PSPP after inguinal herniorraphy is suspected to be neuropathic, as nerve dysfunction has been reported after inguinal herniorrhaphy.2 In addition, a literature-based estimation that took into account certain symptoms of persistent pain, such as numbness, paroxysmal pain or touch-evoked allodynia, stated that 30.5% of persistent pain was probably or definitely of neuropathic origin.1 It has also been suggested that there is less risk of persistent pain with laparoscopic than with open inguinal hernia repair.3 However, it is unknown whether this difference between the 2 techniques is maintained for neuropathic aspects of persistent pain. This mechanism is widely considered to be a factor of severity and chronicization.4 In a recently published prospective open-ended French multicentric cohort study, the risk of persistent neuropathic pain in the 6 months following inguinal hernia repair was estimated at 12.4% for open mesh surgery and 3.2% for laparoscopic surgery.5 We further studied these 2 subcohorts to assess the risk of persistent neuropathic pain associated with laparoscopic and open inguinal hernia repair. Our observational nonrandomized design resulted in unequal distributions of relevant covariates between comparison groups, but the level of evidence was improved by using an analysis based on propensity score.