Non-developed external oblique aponeurosis in inguinal hernia repair: a case report and discussion of the literature

Open inguinal hernia repair is one of the most commonly performed operations in the world. It relies heavily on the presence of an inguinal canal formed by the external oblique aponeurosis and conjoint tendon. Variations of the anatomy of this region are rarely described. We describe a patient with bilateral inguinal hernias and missing external oblique aponeurosis. The patient underwent open repair secondary to previous abdominal surgery and the inability to obtain laparoscopic access. A medline search was performed and we provide a synopsis of the literature. At operation, no clear external oblique aponeurosis could be identified and large defects of the transversalis fascia were corrected. CT images of the anatomic variations are provided. To the best of our knowledge, combined abnormalities of the external oblique aponeurosis and transversalis fascia have not been described before.