Fig. 1

The incisions and port placement of the three-port group (A) and four-port group (B). A: The table surgeon and the robotic arm 1 share the same incision. B: Port 4 as the utility incision is used by the bedside assistant. A maryland bipolar forceps is placed in robotic arm 1 (surgeon left hand); A 30-degree-angle-down stereoscopic camera is placed in robotic arm 2 (middle arm); A permanent cautery hook is placed in robotic arm 3 (surgeon right hand)