Medical Diagnosis
Case 135
【Progress】
She was forbidden to ingest food and water. As her symptoms were not severe, continuous drip infusion was conducted without ileus tube. Two days later, her symptoms almost completely improved.
【Discussion】
At a glance, a gasless abdomen on abdominal radiograph seems to be interpreted as nonspecific (Fig.1) but it includes various diseases such as ascites, pancreatitis, displacement due to large tumor, small bowel obstruction, bowel ischemia and congenital atresia (1). Of these, small bowel obstruction of torsion ileus is the most serious and life-threatening. For making up a gasless abdomen, swallowing air in stomach and gas production in colon should be blocked. Vomiting and diarrhea or defecation appear to be one of the possible factors. Further, small intestine is simultaneously in a state of constriction or filling with fluids. In our patient, she evacuated stool early in the morning. Abdomen CT showed fluid retention in esophagus, stomach, duodenum and small bowels, and constriction of large bowels (Fig.2). Further, abdomen CT showed obturator foramen herniation whose content was fat tissue, part of mesentery (Fig. 2K), indicative of incomplete internal (obturator) hernia, that induced to come off the herniation spontaneously while fasting. She almost completely recovered two days later.
It is sometimes necessary to differentiate small bowel obstruction and infectious enteritis. Features of small bowel obstruction on CT are as follows; dilated small bowel loops > 2.5 – 3.0 cm; normal collapsed loops distally: small feces sign (2). Meanwhile, the typical finding of enteritis is mural thickness of small bowel. The mural thickness and its distribution were key findings to differentiate them and identify the cause of enteritis (3-5). Helicobacter pylori and Anisakis tend to infect stomach, duodenum and proximal bowel. Bacterial infection by Salmonella, Yersinia, and Shigella affect the distal small bowel (3). Further, tuberculosis, amebiasis and Behcet disease involve the distal ileum and cecum, which stay the content for a comparatively long time and own the lymphoid tissue like Peyer’s patches (3-5). In case of Crohn disease, the mural thickness can be greater than 10 mm and the configuration was typically eccentric while in case of ulcerative colitis, the inflamed wall thickness is not as 8 mm with concentric configuration (3-5).
As there is room for writing, I organize here radiological signs about various diseases of bowel diseases (2-5); thumbprinting and accordion sign – pseudomembranous colitis secondary to clostridium difficile; pseudotumor sign – fluid-filled loops of small bowel; small bowel feces sign – proximal to the occlusive transposition point; whirl sign and/or beak sign – volvulus; closed loop sign – two point occlusions; mesenteric edema and ascites – bowel ischemia; pneumatosis and gas in adjacent mesenteric veins – bowel mural necrosis.
【Summary】
We present an eighty nine-year-old female with gasless abdomen due to left obturator canal hernia. For making up a gasless abdomen, swallowing air in stomach and gas production in colon should be blocked Small intestine is simultaneously in a state of constriction or filling with fluids. In our case, CT showed fluid collection in the esophagus, stomach, duodenum and small intestine and constriction of colon due to obturator foramen hernia of mesentery.
It is borne in mind that features of small bowel obstruction on CT are as follows; dilated small bowel loops > 2.5 – 3.0 cm; normal collapsed loops distally: small feces sign. Features of enteritis on CT is mural thickness and its distribution is a key of identifying the causes. Anisakis and Helicobacter pylori affect the proximal small intestine, and bacterial and autoimmune disease affect the distal ileum because of long stay of contents and the existence of specific lymphoid tissue of Peyer’s patches. It should be familiar in radiologic signs to interpret CT findings of small bowel disease: thumbprinting and accordion sign, pseudotumor sign, small bowel feces sign, whirl sign and/or beak sign,and pneumatosis.
【References】
1.Thompson WM. Gasless abdomen in the adult: what does it mean?. AJR Am J Roentgenol. 2008;191 (4): 1093-9.
2.Paulson EK, et al. Review of small-bowel obstruction: the diagnosis and when to worry. Radiology. 2015 May;275(2):332-42.
3.Childers BC, et al. CT Evaluation of Acute Enteritis and Colitis: Is It Infectious, Inflammatory, or Ischemic?: Resident and Fellow Education Feature. Radiographics 2015;35(7):1940-1. doi: 10.1148/rg.2015150125.
4.Finkelstone, L, et al. Etiology of small bowel thickening on computed tomography. Can J Gastroenterol. 2012 Dec; 26(12): 897–901.
5.Macari M, Blathazar EJ. CT of bowel wall thickening: Significance and pitfalls of interpretation. AJR. 2001;176:1105–16.
2019.1.9