Prospective evaluation of a jelly-like conducting medium for catheter US probe imaging of esophageal and duodenal lesions.

BACKGROUND: The catheter probe EUS(C-EUS) relies on luminal water for acoustic coupling. However, in tubular structures, such as the esophagus and the duodenum, instilled water drains away rapidly. The use of water-filled balloons is limited by air artifact and other problems. This study evaluated the image quality, the penetration depth, the tumor staging accuracy, and the safety of C-EUS by using carboxymethylcellulose, an edible, nontoxic, transparent jelly-like substance (JC-EUS).
METHODS: Forty patients with an esophageal or a duodenal submucosal lesion or an esophageal carcinoma were evaluated prospectively in a crossover study with both C-EUS and JC-EUS when using a 12-MHz US catheter probe. Based on still images, depth of US penetration and image quality (by using a predefined 1 to 5 scale) were assessed by a blinded, independent endosonographer. OBSERVATIONS: JC-EUS was superior in image quality compared with C-EUS overall (mean score: 4.9 vs. 2.6; p <0.001), as well as in each subgroup (esophageal carcinoma, esophageal submucosal lesion, duodenal submucosal lesion). Penetration depth was not significantly different (2.5 cm). Staging was 100% accurate in 14 patients with esophageal cancer who underwent surgery. There was no procedure-related complication.
CONCLUSIONS: JC-EUS is safe, provides superior image quality to C-EUS, and is accurate for local staging of esophageal cancer.