To the Editor.—The title, the bulk of the text, and the conclusions of a recent article by Fulenwider et al1 imply that their study applies to the double-as well as to the single-valve Denver peritoneovenous shunt. However, only single-valve Denver shunts were included in the nine-unit series. It is commonly known that double-valve Denver shunts are preferred for the vast majority of shunting candidates, and the single-valve type is recommended only when very viscous ascitic fluid is encountered. Since the double-valve type was commercially available at the time of the Fulenwider series, it is not clear why single- instead of double-valve shunts were tested if the series had to be restricted to one type.
A major beneficial feature of the Denver device was apparently not utilized during the management of the patients in this series. There is no indication in the article that the Denver shunt was regularly