The invention relates to a device and related method for sealing and/or dissecting body tissue using a reverse action instrument. The devices and methods described permit laparoscopic or natural body orifice access to an anatomical space and facilitate sealing portions of tissue together, dissecting tissue or combinations thereof. A surgical instrument for sealing and dissecting body tissue is described having distal and proximal ends with an elongated body. The body includes a jaw member positioned at the distal end that is defined by a stationary arm and a pivotable arm. A moveable closure sleeve is disposed at least partially about the body and the closure sleeve is configured such that coaxial movement of the sleeve along the longitudinal axis of the body causes the jaw member to open or close.
