Spigelian Hernia

An Amyand hernia is an inguinal hernia containing the vermiform appendix.

The appendix may be completely normal, incarcerated, inflamed, gangrenous or perforated. The condition is most commonly right sided, although left sided cases occur with intestinal malrotation, situs abnormalities or a highly mobile caecum.

Management depends almost entirely on the condition of the appendix and degree of contamination, rather than on the label Amyand hernia itself.

Most cases resemble an ordinary inguinal hernia.

When appendicitis develops within the sac, the patient may have an acutely painful irreducible groin swelling with local erythema and tenderness.

Classical migratory appendicitis pain may be absent because the inflamed appendix is confined within the hernia.

Perforation can produce a groin abscess, scrotal infection, abdominal wall infection or generalised sepsis.

Most cases are diagnosed intraoperatively.

CT abdomen and pelvis: can identify the appendix entering an inguinal hernia sac and determine whether inflammation, abscess or bowel obstruction is present.

If the appendix is normal, reduce it into the abdomen and perform standard mesh inguinal hernia repair.

Routine removal of a normal appendix is usually unnecessary in adults because appendicectomy converts a clean operation into a potentially contaminated one and provides no clear benefit. Removal can be considered if the appendix is traumatised, densely adherent within the sac or anatomically abnormal.

If the appendix is acutely inflamed but not perforated, perform appendicectomy. The choice of hernia repair depends on contamination. Carefully selected clean contaminated cases may still undergo synthetic mesh repair, but the decision should account for local contamination, tissue quality and infection risk. Evidence remains limited because Amyand hernia data largely consist of small series and case reports.

If the appendix is gangrenous or perforated, perform appendicectomy and adequate source control. Avoid permanent synthetic mesh when there is frank pus, gross enteric contamination or established local infection.

When perforation produces diffuse peritonitis or the appendix cannot be safely managed through the groin incision, add laparoscopy or laparotomy as required.

For uncomplicated appendicitis within the sac:

Ceftriaxone 2 g IV plus metronidazole 500 mg IV before surgery provides appropriate enteric Gram negative and anaerobic coverage.

For perforation or established complicated intra abdominal infection:

Ceftriaxone 2 g IV every 24 hours plus metronidazole 500 mg IV every 12 hours.

Severe sepsis or extensive contamination may instead be treated with piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, adjusted for renal function.