Sonographic diagnosis of intestinal anisakiasis presenting as small bowel obstruction.

BACKGROUND: To evaluate the accuracy of ultrasonography (US) in the diagnosis of intestinal anisakiasis presenting as small bowel obstruction.
METHODS: We retrospectively reviewed the clinical features, US examinations, and CT scans of seven patients with intestinal anisakiasis presenting as small bowel obstruction. We compared the performances of US and CT in demonstrating peritoneal fluid, small bowel dilatation, and segmental edema of Kerckring's folds.
RESULTS: All patients presented with a history of ingesting raw saltwater fish or squid less than 2 days prior to presentation at the emergency department and had significant levels of Anisakis-specific IgE. Both US and CT revealed small bowel obstruction, with dilated small bowel in all patients and accumulations of free peritoneal fluid in six patients. CT showed segmental wall thickening and luminal narrowing with submucosal edema distal to the distended small bowel; US did so in four patients.
CONCLUSIONS: Although US was inferior to CT in demonstrating the segmental intestinal edema causing small bowel obstruction, it can be applied in suspected cases of intestinal anisakiasis presenting as small bowel obstruction, particularly where CT is unavailable or there are concerns about radiation exposure.