Water Immersion Technique in Endoscopy: A Non-Biopsy Tool for Celiac Surveillance?

How underwater visualization of mucosal villi can rival biopsy in detecting villous atrophy—and when to trust what you see.

The water immersion technique is a relatively simple adjunct to endoscopy. The basic principle of the water immersion technique consists of viewing the mucosa under water, which is applied through the working channel or waterjet of the endoscope, inundating the field of view. The mucosa is then viewed through this “water magnification filed”, and the mucosal villi appear larger and can be very well characterized. The immersion technique has been widely studied by Cammarota et al from Italy. The authors were able to demonstrate a high specificity and sensitivity to diagnose celiac disease. In one study designed to monitor the celiac patient’s response to a gluten-free diet the immersion technique was as good as biopsy to detect villous blunting. Nevertheless, biopsy remains standard for the initial diagnosis of celiac disease but when evaluating these patients on follow-up (i.e. surveillance), a good immersion technique investigation of the small bowel mucosa may suffice to detect active disease (i.e. villous blunting and atrophy).