IS case 517: Amyand hernia
Imaging Sciences URMC 2010
Publication Date: 2010-09-10
Amyand hernia is defined as the herniation of the appendix within the inguinal canal. Claudius Amyand (1680-1740) was a British surgeon who removed an inflamed appendix within the right inguinal hernia of an eleven-year-old boy. The incidence of Amyand hernia is less than 1%. Patients with an inflamed appendix that is incarcerated within the inguinal canal will present with abdominal pain, vomiting, and will variably have fever or leukocytosis. Originally, the term Amyand hernia referred to an inflamed appendix located within the inguinal canal, however, it now encompasses normal appendix within this location as well as inflamed appendix. There are four types of Amyand hernias, which are differentiated based on forms of management. Type one is a normal appendix within an inguinal hernia, and is managed with hernia reduction, mesh repair, with an appendicectomy in young patients. Type two is acute appendicitis within an inguinal hernia, without abdominal sepsis, and is managed with appendectomy with primary repair of the hernia without mesh. Type three is acute appendicitis within an inguinal hernia with abdominal wall or peritoneal sepsis, and is managed with laparotomy, appendectomy, and primary repair of the hernia without mesh. Finally, type four is acute appendicitis within an inguinal hernia with some complicating pathology outside the hernia sac, and is managed with appendectomy through hernia or laparotomy as appropriate, with appropriate investigation of second pathology.
On CT, radiographic features of Amyand hernia include a blind-ending tubular structure that arises from the cecum and courses into the inguinal canal. Sagittal and coronal reconstructions may be of further assistance. There may be mesenteric fat stranding or abscess formation. It is also important to differentiate the appendix from the spermatic cord when evaluating for the presence of this hernia.
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