Concomitant Medial and Interparietal Inguinal Hernias Repaired by the Onstep Technique

A 68-year-old man presented to our department complaining of a swelling in the right inguinal region. On physical examination, two swellings in the right inguinal region were observed. Abdominal com-puted tomography showed signs suggestive of a medial inguinal hernia and a lateral inguinal hernia, but since the lateral inguinal hernia was prolapsed in the craniolateral direction along the line of the abdominal wall, an interparietal hernia was suspected, and surgery was performed. Intraoperatively, the lateral hernial sac was seen to be prolapsed from the internal inguinal ring and to extend between the external and internal abdominal oblique muscles rather than toward the inguinal canal, and an interparietal hernia was therefore diagnosed. A medial inguinal hernia was also identified, and both were repaired simultaneously by the ONSTEP technique. An interparietal hernia is a rare subtype of inguinal hernia. In Japan, it is usually repaired by laparoscopic surgery, but open surgery has the advantage that the direction in which the hernial sac extends can be confirmed directly by identifying anatomical landmarks during surgery. In cases of concomitant hernias, as in the present case, the ONSTEP technique is useful because it enables their simultaneous repair.