Multiple gastrointestinal tract diverticula with ileal diverticulitis

Clinical History

A 76-year old woman was admitted by the general practitioner to the radiology department for lower abdominal pain and elevated C-reactive protein levels for some weeks. There was mild anorexia reported by the patient but no altered stool pattern was noted. There were no urinary or respiratory complaints.

Imaging Findings

Initially an abdominal ultrasound was performed which didn’t show any abnormality. Because of the remarkable elevated C-reactive protein levels (290 mg/l) and painful hypogastric region a CT-scan was performed with intravenous, oral and rectal non-ionic contrast administration.
The abdominal CT showed concentric wall thickening of the pre-terminal ileum with inflammatory reaction in the adjacent mesentery. Multiple ileal diverticula were seen which were already reported on a prior CT. This ileal diverticulitis was complicated by formation of multiple local abscesses (Fig. 1). The patient was treated with antibiotics (Amoxicillin/clavulanic acid) for 10 days (first intravenous, later oral) with favourable evolution. Furthermore a duodenal diverticulum in the descending part as well as colonic diverticulosis were withheld (Fig. 2).
Some weeks later the patient presented again with dysphagia-complaints and food impaction (beef). Contrast X-ray study showed a non-relaxing upper gastroesophageal sphincter with a small Zenker’s diverticulum that was confirmed during endoscopic extraction of the piece of beef (Fig. 3).

Discussion

Small bowel diverticulosis is a rather rare entity (0.1-1.5%) usually found incidentally because it's asymptomatic. Jejunal diverticula are approximately 5 times more frequent than ileal. Small bowel diverticula are considered false diverticula, and usually are multiple. These are outpouchings of the bowel consisting of mucosal and submucosal tissue protruding through a defect in the muscular bowel wall layer. These false diverticula occur at the mesenteric side because of the weak points in the muscular layer created by the penetrating vascular structures. The more common, congenital Meckel’s diverticulum is a true diverticulum, containing all layers of bowel wall, occurring at the antimesenteric border. Similar as with colonic variants, small bowel diverticulosis can have complications (6-13%) such as infection, perforation, abscess or obstruction.[1] As in this case, elevated CRP levels are suggestive for complications (e.g. infection/abscesses).

In the case we described, the patient had multiple gastrointestinal tract diverticula at different sites (Zenker’s, duodenum, ileam and colon) suggesting an underlying anomaly with increased risk of diverticulum formation however in literature no specific diseases are described.[2]

Because of the non-specific complaints of ileal diverticulitis and the very low incidence of the condition, ultrasound is the first choice of technical investigation, mostly for evaluating for e.g. appendicitis. Ultrasound may demonstrate bowel wall thickening, sometimes with a visible adjacent diverticulum. Infiltration of the surrounding fat tissue is a frequent finding. However, ultrasound has a low sensitivity with most cases not as evident as described above.[3]
Historically barium contrast studies had a diagnostic role but it has lost its place in work-up due to the non-specific findings, such as thickened mucosal folds, pressure defects from the associated inflammatory mass and contrast leakage due to perforation with or without evidence of diverticula.[4, 5]
To date, computed tomography (CT) is the gold standard technique due to its high sensitivity and specificity for diverticulitis (99% for colonic diverticulitis [6]). The diagnosis can be made without contrast. Nevertheless both oral and intravenous contrast are recommended. Uncomplicated small bowel diverticulosis is seen as focal, mostly numerous outpouchings of the gastro-intestinal tract. Focal bowel wall thickening with surrounding fatty inflammation may be an eye-catcher for focal inflammation.[3, 4]

Therapy for small bowel diverticulitis is similar to that of colonic diverticulitis as well. A conservative approach is suggested for simple cases with bowel rest, intravenous hydration and intravenous antibiotics. In case of bleeding, obstruction or perforation a surgical intervention is needed, e.g. segmental resection with primary anastomosis.[1, 7]

Differential Diagnosis List

Final Diagnosis

Ileal diverticulitis with multiple abscesses.

URL:	https://www.eurorad.org/case/15500
DOI:	10.1594/EURORAD/CASE.15500
ISSN:	1563-4086