Endoscopic injection sclerotherapy using a transparent overtube with intraluminal negative pressure (np-EIS) for esophageal varices.

Endoscopic injection sclerotherapy (EIS) using the transparent overtube (OT) method can be conducted safely and easily not only in elective esophageal varices but also in emergency cases because of the ability to obtain a good field of view and fixation of the varix. However, application of the OT method is limited because intravariceal injection into small varices through the slit of the OT is impossible. We devised a technique to apply the OT method to small varices by utilizing negative pressure in the OT (np-OT method). By using negative pressure, EIS with a transparent overtube is now suitable for all grades of esophageal varices, and the accuracy of puncture in EIS has been improved. Injection of the target area was successful in all cases. The rate of intravariceal injection has also been improved (47% in low-grade varices) because injection of all sites was possible. We call EIS by the np-OT method "np-EIS".