The valve design of disposable and reusable trocars

The advent of video-laparoscopy has led to many recent improvements in the design of both disposable and reusable trocars and cannulae. This paper discusses the various types of trocar sheath valve mechanisms available to the laparoscopic surgeon. For reusable cannulae it is suggested that controllable flap valves are close to ideal, whilst for disposable cannulae controllable flap valves or silicone leaflet valves allow easy access and retrieval of instruments with minimal loss of pneumo-peritoneum.