Figure 2.

Abdominal surgical posture: a supine position, with the head raised at approximately a 20-degree angle. Five abdominal Traco units were used: a Trocar (camera, 10 mm) was placed 1 cm below the umbilicus. One operation hole was set at the xiphoid, a second operation hole was set between the mid clavicular line and the umbilicus, a third operation hole was set between the anterior axillary line and the midaxillary line, and the operation hole for the assistant surgeon was set at the umbilicus level of the upper left abdomen.