Transient small bowel angioedema due to intravenous iodinated contrast media

Abstract

Three cases of transient proximal small bowel angioedema induced by intravenous administration of nonionic iodinated contrast media (CM) are presented. Computed tomography (CT) images in the venous phase displayed the proximal small bowel with circumferential thickening of the wall including the duodenum and proximal segment of the jejunum. The bowel wall was normal in non-enhanced images, and normal or inconspicuous in arterial phase enhanced images. In one of the three cases, the bowel wall was thickened in venous phase but disappeared in the 40 s delayed phase images. No filling defect was seen in the lumen of the superior mesenteric artery and vein. No peritoneal effusion or mesentery abnormality was found. Each of these patients reported only mild abdominal discomfort and recovered without specific treatment within a short time. Only one patient suffered mild diarrhea after scanning which had resolved by the following day. The transient anaphylactic small bowel angioedema due to intravenous iodinated contrast media was easily diagnosed based on its characteristic CT findings and clinical symptoms. Differential diagnosis may include inflammatory and ischemic bowel disease, as well as neoplasms. A three-phase CT protocol and good understanding of this disorder are fundamentally important in the diagnosis of this condition. The supposed etiology behind the transient anaphylactic reaction to intravenous administration of iodinated CM in small bowel is similar to other CM-induced hypersensitive immediate reactions. The predilection location of transient anaphylactic bowel angioedema is the small intestine, particularly the proximal segment. A speculated cause may be the richer supply of vessels in the small intestine, ample mucous folds and loose connective tissue in the duodenum and the jejunum.

The molecular mechanism of contrast-induced nephropathy (CIN) and its link to in vitro studies on iodinated contrast media (CM)

“…Chemical effects are mainly referred as contrast-induced nephropathy (CIN) and will be discussed later. Anaphylactic reaction is the most common situation in constitutional effect and may cause mild symptom such as nausea and vomiting, dizziness, rash and itch, or chest discomfort, shock in more severe situation, or even death [ 21 , 23 , 28 , 29 , 32 ]. Iodinated contrast media cause little allergic reactions, especially for low-osmolar contrast media (LOCM).…”

Transient angioedema of small bowel secondary to intravenous iodinated contrast medium

“…Cutaneous allergy-like reactions are well known, but transient angioedema of the small bowel as an adverse contrast reaction is rarely documented, with less than eight cases reported in English literature. [ 2 4 5 ] The incidence of post iodinated contrast angioedema of the skin and upper airway mucosal membranes is 0.01%. [ 6 ] However, the exact incidence of bowel wall angioedema is not known as it is an underreported entity.…”

“…It has been hypothesized that proximal small bowel is predisposed to angioedema because of its richer blood supply, larger mucosal folds, and loose connective tissue. [ 2 ]…”

“…[ 1 ] Gastrointestinal manifestations are uncommon, with transient angioedema of bowel being a rarely reported entity. [ 2 ] This article illustrates the imaging findings of transient angioedema of the bowel on computed tomography (CT) examination.…”

Transient Small Bowel Angio-oedema Secondary to Intravenous Iodinated Contrast Medium

“…The 20-minute delayed scan showed mild reduction in the small bowel mural edema as compared with the venous phase images and also appearance of mild peri-enteric and mesenteric fat stranding (►Fig. 3).…”