Clinical History
A 67-year-old man had progressive abdominal complaints, which were non-specific and eventually caused substantial weight loss. Thirty minutes after eating he suffered from severe pain and sometimes cramp attacks in his upper abdomen. His previous medical history was unremarkable. Blood analysis, ultrasound and upper endoscopy did not show any abnormalities.
Imaging Findings
A multislice abdominal CT after intravenous contrast was performed, which at the first glance showed abnormal dilatation of the proximal small bowel in the left upper abdomen. When inspecting this region more carefully, multiple diverticula with small orifices could be identified. Focal intestinal pneumatosis was seen in a few diverticula. There were no signs of perforation or portal venous air. Some bowel parts showed the “small bowel faeces sign” [1], consistent with subacute or low-grade obstruction. There was no obvious identifiable transition point, mass or mural thickening. The jejunal villous architecture was preserved. The mesenteric fat was not infiltrated and the mesenteric lymph nodes were not enlarged.
A laparoscopy was performed, which showed massive jejunal dilatation and multiple jejunal diverticula with a small part at the distal end having a thickened bowel wall. The surgeon resected 1.5 meters of the proximal jejunum. The complaints disappeared completely after the operation.
Discussion
Small bowel diverticula are sac-like extraluminal mucosal herniations emerging within the internal lining at the entrance of the mesenterial vessels (locus minoris resistentiae), probably as a result of dyskinesia and increased intraluminal pressure.
Small-bowel diverticulosis is most frequently located in the duodenum. Jejunal diverticula are more rare, with a prevalence in barium studies and autopsy from 1 to 2% [2]. Patients are typically in their 6th or 7th decade.
Generally, these lesions are only discovered incidentally or in case of complications causing acute abdominal symptoms due to perforation, bleeding, obstruction (bezoar/stricture), or infection. [2-5] The diverticula can cause longstanding non-specific abdominal complaints like epigastric pain or a bloating sensation, but most patients are symptom-free. Stasis in the diverticula causes bacterial overgrowth, which can result in diarrhoea and malabsorption.
Until recently, these lesions were more often described in small-bowel barium studies, but due to a shift toward CT, barium studies are currently seldom performed. Fintelmann et al. point out the pitfall of missing or underestimating the diverticular disease on CT probably because of the subtle criteria and the relatively rare diagnosis [2]. Diverticula can be seen on CT images as ovoid or round structures outside the lumen of the small bowel with smooth, barely discernible walls without small-bowel folds. Sometimes, small-bowel wall emphysema is present because the thin wall of the diverticula enables luminal gas to translocate into the wall. This pneumatosis has to be differentiated from other causes like ischemia or infection. No portal venous air should be found. The diverticula are filled with fluid, air or, in chronic stasis, stool-like components can be seen because of water absorption (small bowel faeces sign). [1] They can be easily overlooked and mistaken for loops themselves. Recognition of the eccentric location and multiplanar analysis visualizing the orifices can give the clue. In complicated diverticular disease the affected area is identified by secondary signs like fatty infiltration (diverticulitis), contrast extravasation (active bleeding), or free intra-abdominal air (perforation).
Treatment is generally surgical resection of the affected bowel segment.
In conclusion, jejunal diverticulosis can be related to aspecific abdominal complaints. The diverticula can be seen as spheric structures with a thin, smooth wall without folds outside, but with a connection to the small-bowel lumen. Careful reading of the CT examination paying special attention to the small bowel can lead to the diagnosis and may prevent the risk of possible complications.
Differential Diagnosis List
Jejunal diverticulosis
Perforated neoplasm
Foreign body perforation
Crohn’s disease
Small bowel ulcerations from non-steroidal anti-inflammatory drugs
