CASE 8978 Published on 08.11.2010

A case of small bowel perforation due to a fish bone (ESGAR 2010 Case of the day)

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Kalogeropoulou C, Kraniotis P, Zampakis P, Petsas T.
University Hospital of Patras, Department of Radiology, Patras, Greece.

Patient

76 years, male

Categories
Area of Interest Abdomen ; Imaging Technique CT
Clinical History
A 76 year old man presented with left lateral abdominal pain and fever. Clinical examination revealed localized tenderness with rebound sign. Laboratory investigation revealed leukocytosis. The patient was submitted to MDCT for further diagnostic work-up.
Imaging Findings
CT depicted the presence of extraluminal air bubbles (red arrows in Fig 1a-d) in the left lateral mid-abdomen; some with linear pattern. There was marked mucosal enhancement in the small bowel loops of the left lateral mid-abdomen (green arrows in Fig 1c-e). Fat stranding was also noted in the aforementioned region, with small amounts of scattered fluid (blue arrows in Fig 1a-e) in the vicinity. The small bowel loops were fluid-filled and dilated with air-fluid levels, consistent with adynamic ileus. Further search revealed the presence of an elongated hyperdense formation (yellow arrow in Fig 1e) within the lumen of a small bowel loop, in the abnormal region. The finding was more conspicuous on the thick slab axial and sagittal reformatted images (Fig 2a-b). Incidentally there were marked atherosclerotic lesions in the aorta and its branches (inferior mesenteric artery). The findings were consistent with small bowel perforation due to the presence of a foreign body. Small bowel perforation due a fish bone was confirmed at surgery.
Discussion
About 80% of ingested foreign bodies that reach the stomach, pass uneventfully through the GI tract. Perforation occurs in less than 1% of cases. This is usually produced by objects with sharp pointed ends, such as fish bones, chicken bones and toothpicks. Although perforation can occur at any site in the GI tract, the ileocecal region is the most common area. Blind segments (appendix, diverticula and hernias) as well as normal flexures, curvatures and areas of bowel narrowing are also predisposed to perforation.
Fish bones are the most common foreign bodies to cause bowel perforation. As foreign bodies, fish bones are effective perforators since they are sharp at both ends, are frequently swallowed and lodge easily in the bowel due to their curvature. Fish bones are also the most common foreign body to cause perforation of Meckel's and jejunal diverticula. Three mechanisms have been suggested for perforation by foreign bodies: 1. A small, sharp foreign body is pushed through the bowel wall with minimal necrosis. 2. A foreign body produces an area of necrosis and works its way through the bowel wall. 3. A foreign body produces an area of necrosis that secondarily perforates after the object has passed on.
Since the symptoms from foreign body perforation of the GI tract are similar to those of other intra-abdominal conditions, the diagnosis was rarely made preoperatively, in the past. These patients often present with acute abdomen, which can be mistaken for appendicitis, diverticulitis, cholecystitis, small bowel obstruction, or incarcerated hernia. The correct diagnosis can be further obscured since most patients are unaware of having ingested a foreign body. Conventional radiographs of the abdomen are often unrevealing. The ingested foreign body will not be identified unless it is sufficiently radiopaque. Although radiographs might show evidence of small bowel obstruction, the aetiology usually remains obscure. CT scan is valuable in this setting since it may demonstrate findings suggestive of small bowel perforation, visualize the foreign body and determine the presence of any associated complications such as abscess or obstruction.
Differential Diagnosis List
Fish bone causing small bowel perforation.
Small bowel obstruction
Ischemia
Final Diagnosis
Fish bone causing small bowel perforation.
Case information
URL: https://www.eurorad.org/case/8978
DOI: 10.1594/EURORAD/CASE.8978
ISSN: 1563-4086