Stump appendicitis: a forgotten diagnosis

Clinical History

A 20-year-old man with a 72-hour history of right iliac fossa pain, loss of appetite, nausea, vomiting and increase in both white blood cell count and CRP level.

His medical history was non-contributory, but surgical history was notable for a laparoscopic appendectomy performed one year ago because of gangrenous appendicitis.

Imaging Findings

An abdominal ultrasound (US) revealed a hypoechoic, aperistaltic, non-compressible, dilated (8.5 mm outer diameter) tubular structure with thickened walls, arising on the caecum in the right iliac fossa. Hyperechogenicity of local fat and a small amount of peritoneal fluid were also noted (Fig. 1).

Because of the possibility of an inflammation of the appendicular stump, an abdominal contrast-enhanced Computed Tomography (CT) examination was also requested, which showed similar findings: a tubular structure extending from the base of the caecum with thickened and enhancing walls, stranding of the adjacent fat (Fig. 2) and a 0.8 cm periappendiceal fluid collection (Fig. 3). There were also findings representing the surgical staple line from the previous appendectomy (Fig. 4).

The patient underwent an urgent laparotomy and a retrocaecal abscess was found close to a 1 cm appendicular stump. A resection of the stump and abscess drainage were performed. Postoperative course was uneventful and he was discharged 4 days after admission.

Discussion

Short-term complications associated with appendectomy include wound and deep infections, stump disruption and bleeding. Late complications include hernias, bowel obstructions and stump appendicitis (SA) [1, 2].

SA is a rare complication first described by Rose in 1945 [3], in which an appendicular remnant becomes inflamed at some point after inadvertent partial appendectomy.

The true incidence of SA is unknown, although it is estimated in 1:50,0000 cases [4]. It has been described after open and laparoscopic appendectomy [2, 4-6]. It appears to be more frequent in men and clinical presentation mimics symptoms and signs of previous appendicitis. Abdominal pain is the commonest symptom [2].

Clinical findings can appear any time, with cases described from 4 days to 50 years after surgery [2, 7]. In our case, symptoms started one year after appendectomy.

Like regular appendicitis, its origin seems to be an obstruction of the remnant´s lumen [2, 4-6]. The length of the appendicular stump in most of the SA reported cases is more than 0.5 cm (0.5 cm to 6.5 cm), and as a consequence it has been recommended that the appendicular stump should be less than 0.5 cm [2, 6]. Severe local inflammation and/or retrocaecal position of the appendix may favour an incomplete appendectomy.

Since the first description of the technique by Puylaert [8], graded compression US became the method of choice in the study of young and thin patients with right iliac fossa pain.

US signs of SA are similar to those found in regular appendicitis [5, 9]. In cases with previous appendectomy as in our patient, the presence of a tubular, non-compressible, aperistaltic structure of more than 6 mm in diameter, close to the caecum, with hyperechogenicity of the adjacent fat should suggest a diagnosis of SA.

Sometimes diagnosis by US could be quite complicated. It is in cases where IV contrast-enhanced CT examination is a good alternative because of its high sensitivity and specificity in the diagnosis of the acute process with abdominal pain [10, 11].

Treatment involves surgery to remove the appendicular remnant.

• SA is an inflammation of a large residual appendicular stump with clinical findings similar to those of previous appendicitis.
• In patients with symptoms of acute appendicitis and a previous history of appendectomy, SA should be incorporated into the differential diagnosis.
• A delayed diagnosis of SA must be avoided and in order to achieve this, imaging techniques such as US and CT should be used.

Differential Diagnosis List

Final Diagnosis

Inflammation of the appendicular remnant: stump appendicitis

URL:	https://www.eurorad.org/case/12710
DOI:	10.1594/EURORAD/CASE.12710
ISSN:	1563-4086