Trocar arrangement during the robot assisted thoracoscopic phase. (a) Trocar arrangement during robot-assisted thoracoscopic phase. La, left robotic arm (fourth intercostal space); a, assistant thoracoscopic working port (fifth and seventh intercostal space); ca, robotic camera arm (sixth intercostal space); ra, right robotic arm (eighth intercostal space) . (b) Trocar arrangement during the laparoscopic abdominal phase. The camera was inserted through the 10 mm para-umbilical trocar port and two 5 mm trocars were used as laparoscopic working ports. The liver retractor was inserted through the 12 mm right para-rectal trocar port. The harmonic scalpel was inserted through the 12 mm paraumbilical port .