A flexible, fluid tight envelope (278) (324) (364) provides access for a hand and surgical instruments through a body tissue incision while maintaining insufflation pressure or a pneumoperitoneum within the body. The envelope is transparent and has an internal volume with opposite proximal and distal ends. A first opening in the envelope at the proximal end adjoins the incision and is secured and sealed to the body tissue. The second opening at the envelope distil end is provided with a closure member (350) that seals closed the second opening on itself or around the forearm of a surgeon or a surgical instrument inserted therein. An access port (284) (292) is provided at the first opening. The access port includes a housing (250) (290) (362) containing a valve element (282) [300) (392) that can be selectively opened and closed to provide access to the incision while maintaining insufflation pressure in the body cavity.
