Fig. 1

Intraoperative images of a difficult case of No. 6 lymph node dissection. Two representative images of a difficult case are shown (a, b). The top of the pancreas was far from the root of the RGEV, and longer LND was required than in an average case. We defined this characteristic, i.e., dissection along the RGEV required a distance of > 2 cm, as difficulty of No. 6 LND. RGEV right gastroepiploic vein, ASPDV anterior superior pancreaticoduodenal vein, ARCV accessory right colic vein, LND lymph node dissection