Pre‐medication with pronase reduces artefacts during endoscopic ultrasonography

Summary Background : Gastric mucus usually induces artefacts during endoscopic ultrasonography. Aim : To investigate the effectiveness of pre‐medication with the proteolytic enzyme, pronase, before endoscopic ultrasonography. Methods : Out‐patients scheduled for endoscopic ultrasonography were randomly assigned to oral pre‐medication with the anti‐foam agent, dimethylpolysiloxane, alone (treatment A; n = 29), with dimethylpolysiloxane plus sodium bicarbonate (treatment B; n = 29) or with dimethylpolysiloxane, sodium bicarbonate and pronase (treatment C; n = 29). All drinks were given about 10 min before the start of the procedure. After insertion of the endoscope, endoscopists recorded visibility scores before the procedure, imaging scores at endoscopic ultrasonography and the numbers of high‐echo spots in the gastric cavity and on the gastric wall surface after the procedure. Results : Pre‐medication with pronase (treatment C) significantly reduced (both at P