Endoscopic ultrasonography using a 15/20 MHz probe in a direct contact technique: evaluation and application in...

Endoscopic ultrasonography (EUS) has been recently developed as a new diagnostic technique for portal hypertension. However, its conventional water-filled balloon technique is not suitable for the evaluation of esophageal varices, because the vessel lumen is compressed by the inflated balloon. Particularly for small varices, the vessel tends to collapse and is difficult to display. A miniature ultrasonic probe for use via the forceps channel in EUS has been developed and is expected to overcome this difficulty. Here we report the efficacy of this new probe in patients with esophago-gastric varices. Instead of using a water-filled balloon for an acoustic window, we displayed the EUS findings from the new probe in direct contact with gastrointestinal wall by removing air from the lumen under vacuum. Both conventional endoscopy and the new EUS were performed on 3 patients with esophageal varices. The transforceps-channel ultrasonic probe visualized grade 1 varices in addition to the larger varices, confirming this technique to be a useful method for assessing of esophageal varices. Moreover, this method does not require a specially designed endoscope for EUS, rather it can be employed in combination with conventional endoscopy. We conclude that this new technique is a preferred diagnostic technique, and it should become more widely accepted for routine clinical applications.