Fig. 2

a Placement of the four ports. The assistant port was placed on the left side of the abdomen. b Laparoscopic view via the medial-retroperitoneal approach. c The tumor was in the right iliopsoas muscle (yellow arrowheads). d Comparison of the main feeder shown by 3D imaging and as seen in the operative view. The feeding artery (white arrow) depicted on the 3D images was consistent with that seen in the actual operative field