CASE 9392 Published on 24.06.2011

Appendicitis in an incisional hernia - a case diagnosed prospectively with MDCT

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Hegarty C, Kileen RP, Heaslip I, Heffernan EJ

Patient

57 years, female

Categories
Area of Interest Abdominal wall ; No Imaging Technique
Clinical History
A 57-year-old obese female patient attended the ED with a 3 day history of abdominal pain, nausea and vomiting.
The patient’s medical history was significant for a previous open cholecystectomy via a midline laparotomy incision. She had a very large incisional hernia.
Imaging Findings
A chest X-ray and plain film of the abdomen were unremarkable. The working diagnosis at this time was of incarcerated incisional hernia. The patient was commenced on iv fluids, a naso-gastric tube and urinary catheter were placed and CT abdomen and pelvis (with oral and intravenous contrast) arranged.
CT demonstrated a large midline incisional hernia containing loops of non-distended small bowel. Extensive inflammatory fat stranding was seen to the right of the herniated loops of small bowel in the hernial sac and in the sub-cutaneous soft tissues. The inflammatory changes surrounded a thickened blind ending tubular structure arising from the caecum in keeping with the appendix. A calcified appendicolith was present at the base of the appendix (Fig 1, 2). There was no evidence of perforation, fluid collection or abscess.
Discussion
The patient proceeded to midline laparotomy where the incisional hernial sac was opened and the peritoneal cavity accessed. A perforated gangrenous appendix was encountered and appendectomy performed. The hernial sac was completely excised and primary closure of the hernial defect was performed. Post-operatively the patient made an uneventful recovery and was discharged on the 14th post operative day. Pathological examination of the specimen reported severe, acute, necrotising appendicitis.
Whilst appendicitis is a relatively common condition, appendicitis that occurs in herniae is a rare entity. Acute appendicitis occurring in herniae has a reported incidence of 0.13% of all cases of acute appendicitis [1].

Surgical diagnosis of appendicitis occurring in an incisional hernia has been previously described [2], but we believe this to be the first prospective CT diagnosis of appendicitis occurring in an incisional hernia.
Various eponyms exist when appendicitis occurs in specific herniae.
Amyand’s hernia is defined as the presence of the vermiform appendix within an inguinal hernial sac. The appendix may be normal, inflamed or perforated.
Claudius Amyand practised surgery in the late 17th and early 18th centuries and was surgeon to King George II of England. He is credited with performing the first successful appendectomy in 1735. In this case an 11 year old boy presented with acute appendicitis within an inguinal hernial sac. The appendix had perforated as a result of the child having previously swallowed a pin [3].
The presence of the appendix in a femoral hernia is known as DeGarengot’s hernia who first described this in 1731.
The appendix may also be found in spigelian herniae, obturator herniae [4] and umbilical herniae [5, 6].
The diagnosis of appendicitis in herniae is a difficult clinical diagnosis and the diagnosis is most commonly made intra-operatively [1].
The increasing use of CT imaging prior to surgery in difficult clinical cases, where features of hernia and acute appendicitis co-exist is likely to lead to more prospective diagnoses of these rare entities. The primary consideration in most of these cases is that of incarcerated or strangulated inguinal herniae. As a result it is important to be aware of the possibility of appendicitis occurring in herniae and consider this entity when an inflammatory process in a hernia is encountered.
Differential Diagnosis List
Acute appendicitis occurring in an incisional hernia
Strangulated hernia
Incarcerated Hernia
Bowel Ischaemia
Final Diagnosis
Acute appendicitis occurring in an incisional hernia
Case information
URL: https://www.eurorad.org/case/9392
DOI: 10.1594/EURORAD/CASE.9392
ISSN: 1563-4086