A single-lumen surgical device intended to be percutaneously inserted through the abdominal wall to create an access port for a laparoscope/laparoscopic instrument during laparoscopy. The cannula is provided with a shut-off valve for gas/fluid supply, and other sealing devices (e.g., dedicated seals/rings, caps, valves), to prevent insufflation gas leakage whilst allowing entry of instruments; it may additionally be intended for thoracoscopy whereby the valve may not be required. It may include a sharp or blunt trocar blade to assist introduction and/or puncture the abdominal wall; if the trocar is included it may be referred to as a trocar or trocar assembly. This is a single-use device.