Background: Inguinal hernias are a common cause of groin pain. Most hernias are detectable by clinical examination and many patients proceed to hernia repair on the basis of history and examination findings alone. However, a significant proportion of patients with symptoms suggestive of groin hernia are found to have a normal clinical examination. Several radiological techniques have been developed to solve the dilemma posed by occult inguinal hernias. No systematic review or meta-analysis has addressed this common clinical problem.
Methods: A systematic review and meta-analysis were undertaken of relevant articles in Medline, Embase, and the Cochrane database. Studies were assessed using the QUADAS tool. Statistical analysis was undertaken.
Results: We have shown in this meta-analysis that ultrasound has a sensitivity of 86% and a specificity of 77% in occult inguinal hernias. Computed tomography has a sensitivity of 80% and a specificity of 65%. Herniography has a sensitivity of 91% and a specificity of 83%.
Conclusions: Based on this systematic review, herniography should be considered as the initial investigation for occult inguinal hernia where available. In centers where this is not available, ultrasound of the groin should be used with good clinical judgment. When there is still diagnostic uncertainty, further investigation with magnetic resonance imaging should be considered to exclude alternative pathology.