Background and purposes: Carbon dioxide is the common gas material to establish pneumoperitoneum to provide working space for laparoscopic surgeries, but possesses risks of reduced cardiac output and hypercarbia in cases with limited cardiopulmonary reserve. For such cases, we design a novel trocar to reduce the intrabdominal pressure, so as to perform the same operation safely. Animals and Methods: The novel trocar has four flexible leaflets that can be fixed as ¡§extended status¡¨ to hold the inner surface of abdominal wall. When the trocar was tracted upward with iron wires, the abdominal wall can be elevated. The lowest pressure of pneumoperitoneum with the usage of the novel trocar was tested first. We found the pressure was dependent on the target organ. Laparoscopic cholecystectomy was performed to compare the advantage of the novel trocar over the conventional trocar because it is one of the most commonly performed surgeries. Totally 6 pigs were used. They were divided into two groups: 3 pigs as the control group receiving operation with the conventional trocars (group C) under 15 mm Hg pneumoperitoneum, and another 3 with the novel trocar (group N) under 5 mm Hg pneumoperitoneum. Results: The total operation time was significantly longer in group N but the precise dissection time was comparable with group C. No surgical complication was noted in both groups and the blood loss was minimal. The hypercarbia was of a much lesser degree in group N compared to that in group C. Conclusions: Our preliminary data show that with the novel trocar, the laparoscopic cholecystectomy could be smoothly completed under a lesser pressure of 5 mm Hg CO2 pneumoperitoneum in pigs.