Computed Tomographic (CT) images of bowel (caecum) gangrene secondary to suspected caecal volvulus

Clinical History

A 77-year-old lady presented with right iliac fossa (RIF) pain for 5 days. The pain was sharp and constant with gradual increase in severity. It was associated with decrease in appetite, normal bowel habit and three times vomiting. She had a previous history of hypertension, diabetes, stroke and myocardial infarction 3 years before.

Imaging Findings

Following presentation with above symptoms, abdominal X-ray was performed. The X-ray showed no obvious abnormality apart from distended transverse colon and caecum (Fig. 1). So CT abdomen was done because there was deterioration in the clinical symptoms and signs with increasing abdominal pain and tenderness. CT showed inflammatory changes in the right-sided colon and wall thickening in ascending colon and hepatic flexure (Fig. 2). There was gas within the caecum wall (Intramural pneumatosis) consistent with ischaemic bowel with infarction (Fig. 3, 4). Some gas locules were seen outside the wall which suggests localised perforation (Fig. 5).
The caecum was in an unusual position and there were extensive inflammatory changes in the adjacent colon [1]. It is possible that there was transient caecal volvulus especially in the absence of obvious vascular insufficiency (Fig. 6, 7), diverticulitis or neoplasm.
The surgical report mentioned that there was extensive gangrene without finding the cause.

Discussion

Ischaemic bowel disease encompasses a number of clinical entities [2], all with an end result of insufficient blood supply to a segment or the entire colon. This disease results in ischaemic necrosis of varying severities that can range from superficial mucosal involvement to full-thickness transmural necrosis. Various conditions that cause mesenteric ischaemia are:
1) Hypoperfusion: This may involve heart failure or prolonged shock of any aetiology
2) Thromboembolism
3) Bowel obstruction
4) Neoplasm causing venous compression or hypercoagulability
5) Abdominal inflammatory conditions such as appendicitis, diverticulitis, or abscess, venous congestion from cirrhosis (portal hypertension)
6) Vasculitis
7) Drugs like ergotamines, cocaine and vasopressive drugs
8) Trauma
9) Radiation

Imaging findings of bowel ischaemia are similar regardless of the primary cause. Radiographic findings of bowel ischaemia at plain X-ray are [3, 4]:
1) Normal
2) Thickening of bowel wall
3) Submucosal focal mural thickening or thumbprinting
4) Adynamic ileus
5) Intramural gas (pneumatosis)
6) Dilated bowel loops
Computed tomography (CT) can demonstrate the ischaemic bowel segment and may be helpful in determining the primary cause. The Radiographic findings are [4, 5]:
1) Thickening of bowel wall
2) Mesenteric arterial or venous thromboembolism
3) Portal venous gas
4) Intramural pneumatosis
5) Free air in the abdominal cavity in case of perforation
6) Other CT findings include: bowel obstruction; loss or increase of bowel wall enhancement (Fig. 8); engorgement of mesenteric veins; inflammatory changes in the surrounding organs or infarction of other abdominal organs and finding the underlying cause, for instance, tumour .
Nowadays, CT Angiography is the gold standard for demonstrating diminished blood supply to a bowel segment and shows arterial blockage due to emboli or thrombus and Intraoperative fluorescein administration may be required to highlight those areas of bowel that need resection.
However, regardless of the primary cause, the imaging findings of bowel ischaemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. It is very important for the radiologist to understand the pathogenesis of various conditions that cause mesenteric ischaemia, as this will help to recognise ischaemic bowel disease early and avoid delayed diagnosis of this urgent disease and this will help to provide the optimal management as soon as possible.

Differential Diagnosis List

Final Diagnosis

Caecal gangrene secondary to suspected caecal volvulus

URL:	https://www.eurorad.org/case/9219
DOI:	10.1594/EURORAD/CASE.9219
ISSN:	1563-4086