Nerve identification during open inguinal hernia repair: a systematic review and meta-analyses

Purpose: Inguinal hernia repair is one of the most common operations worldwide and despite this, the incidence of chronic pain remains high after inguinal hernia repair. The optimal nerve handling strategy is controversial and the rate at which nerves are identified remains uncertain. This study aimed to determine the identification rates of the ilioinguinal, iliohypogastric, and genitofemoral nerves as well as nerve handling strategies. Methods: This review was registered on PROSPERO (CRD 42023416576). PubMed, Embase, and Cochrane Central were systematically searched. Studies with more than 10 patients were included if they reported an identification rate for at least one of the nerves during elective open inguinal hernia repair in adults. Studies requiring nerve identification in their study design were excluded. Bias was assessed with the JBI critical appraisal tool and Cochrane’s RoB-2 tool. The overall estimate of the prevalence was analysed with prevalence meta-analyses. Results: A total of 23 studies were included. The meta-analyses included 18 studies, which resulted in an identification rate of 82% (95% CI: 76–87%) for the ilioinguinal nerve, 62% (95% CI: 54–71%) for the iliohypogastric nerve, and 41% (95% CI: 27–55%) for the genitofemoral nerve. Nerves were spared in 82% of all repairs. Conclusion: The ilioinguinal, iliohypogastric, and genitofemoral nerves were identified in 82%, 62%, and 41% of surgeries, respectively. Most studies used a nerve-preserving strategy. The role of nerve identification in the development of chronic pain remains uncertain, as well as the optimal nerve handling strategy.